Research IndicatorsGraph generated 25 June 2015 using data from PubMed using criteria.
Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic. Tag cloud generated 25 June, 2015 using data from PubMed, MeSH and CancerIndex
Specific Cancers (4)
Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.
Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).
OMIM, Johns Hopkin University
Referenced article focusing on the relationship between phenotype and genotype.
International Cancer Genome Consortium.
Summary of gene and mutations by cancer type from ICGC
Cancer Genome Anatomy Project, NCI
COSMIC, Sanger Institute
Somatic mutation information and related details
Search the Epigenomics database and view relevant gene tracks of samples.
Latest Publications: SCGB3A1 (cancer-related)
Dai D, Dong XH, Cheng ST, et al.Aberrant promoter methylation of HIN-1 gene may contribute to the pathogenesis of breast cancer: a meta-analysis.
Tumour Biol. 2014; 35(8):8209-16 [PubMed
] Related Publications
We conducted the present meta-analysis of relevant cohort studies to evaluate whether promoter methylation of the high in normal-1 (HIN-1) gene contributes to breast cancer. The MEDLINE (1966 ~ 2013), Cochrane Library (Issue 12, 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), Web of Science (1945 ~ 2013), and Chinese Biomedical (CBM) (1982 ~ 2013) databases were searched without any language restrictions. Meta-analyses were conducted using Stata software (version 12.0; Stata Corporation, College Station, TX, USA). Crude odds ratios (ORs) with their 95 % confidence interval (CI) were calculated. Nine clinical cohort studies that enrolled a total of 693 breast cancer patients were included in the meta-analysis. The results of our meta-analysis demonstrated that HIN-1 methylation frequency in cancer tissue was significantly higher than that of normal and benign tissues (cancer tissue vs. normal tissue: OR = 52.60, 95 % CI = 33.77 ~ 81.92, P < 0.001; cancer tissue vs. benign tissue: OR = 2.38, 95 % CI = 1.53 ~ 3.70, P < 0.001; respectively). Ethnicity-stratified analysis indicated that HIN-1 promoter methylation was correlated with the pathogenesis of breast cancer among both Asians and Caucasians (all P < 0.05). Our findings provide empirical evidence that aberrant HIN-1 promoter methylation may contribute to the pathogenesis of breast cancer. Thus, aberrant HIN-1 promoter methylation could be an independent and important biomarker used in predicting the prognosis and progression of breast cancer.
Vasiljević N, Scibior-Bentkowska D, Brentnall AR, et al.Credentialing of DNA methylation assays for human genes as diagnostic biomarkers of cervical intraepithelial neoplasia in high-risk HPV positive women.
Gynecol Oncol. 2014; 132(3):709-14 [PubMed
] Free Access to Full Article Related Publications
OBJECTIVE: Testing for high risk human papillomavirus (HR-HPV) is increasing; however due to limitations in specificity there remains a need for better triage tests. Research efforts have focused recently on methylation of human genes which show promise as diagnostic classifiers.
METHODS: Methylation of 26 genes: APC, CADM1, CCND2, CDH13, CDKN2A, CTNNB1, DAPK1, DPYS, EDNRB, EPB41L3, ESR1, GSTP1, HIN1, JAM3, LMX1, MAL, MDR1, PAX1, PTGS2, RARB, RASSF1, SLIT2, SOX1, SPARC, TERT and TWIST1 was measured by pyrosequencing in cytology specimens from a pilot set of women with normal or cervical intraepithelial neoplasia grade 3 (CIN3) histology. Six genes were selected for testing in Predictors 1, a colposcopy referral study comprising 799 women. The three genes EPB41L3, DPYS and MAL were further tested in a second colposcopy referral study, Predictors 2, comprising 884 women.
RESULTS: The six genes selected from the pilot: EPB41L3, EDNRB, LMX1, DPYS, MAL and CADM1 showed significantly elevated methylation in CIN2 and CIN3 (CIN2/3) versus ≤CIN1 in Predictors 1 (p<0.01). Highest methylation was observed in cancer tissues. EPB41L3 methylation was the best single classifier of CIN2/3 in both HR-HPV positive (p<0.0001) and negative samples (p=0.02). Logistic regression modeling showed that other genes did not add significantly to EPB41L3 and in Predictors 2, its classifier value was validated with AUC 0.69 (95% CI 0.65-0.73).
CONCLUSION: Several methylated genes show promise for detecting CIN2/3 of which EPB41L3 seems the best. Methylated human gene biomarkers used in combination may be clinically useful for triage of women with HR-HPV infections.
BACKGROUND: The aim of the present study was to investigate within ovarian carcinoma and normal ovarian biopsies the gene expression of multiple secretoglobin family members relative to mammaglobin B, which we previously reported as a promising novel ovarian carcinoma prognostic marker.
METHODS: Using quantitative real-time Reverse Transcription PCR we tested 53 ovarian carcinoma and 30 normal ovaries for the expression of 8 genes belonging to the secretoglobin family: mammaglobin A, lipophilin A, lipophilin B, uteroglobin, HIN-1, UGRP-1, RYD5 and IIS. Next, we decided to expand the LipB gene expression analysis to a further 48 ovarian carcinoma samples, for a total of 101 tumor tissues of various histologies and to study its protein expression by immunohistochemistry in formalin-fixed paraffin-embedded tumors and normal ovaries. Finally, we correlated lipophilin B gene and protein expression to conventional patient clinico-pathological features and outcome.
RESULTS: We found significant mammaglobin A, lipophilin A, lipophilin B and RYD5 gene overexpression in ovarian carcinomas compared to normal ovaries. Lipophilin B mRNA showed a higher presence in tumors (75.4%) compared to normal ovaries (16.6%) and the most significant correlation with mammaglobin B mRNA (rs =0.77, p < 0.001). By immunohistochemical analysis, we showed higher lipophilin B expression in the cytoplasm of tumor cells compared to normal ovaries (p < 0.001). Moreover, lipophilin B gene overexpression was significantly associated with serous histology (serous vs clear cell p = 0.027; serous vs undifferentiated p = 0.007) and lower tumor grade (p = 0.02). Lower LipB mRNA levels (low versus high tertiles) were associated to a shorter progression-free (p = 0.03, HR = 2.2) and disease-free survival (p = 0.02, HR = 2.5) by univariate survival analysis and, importantly, they remain an independent prognostic marker for decreased disease-free (p = 0.001, HR = 3.9) and progression-free survival (p = 0.004, HR = 2.8) in multivariate Cox regression analysis.
CONCLUSIONS: The present study represents the first quantitative evaluation of secretoglobin gene expression in normal and neoplastic ovarian tissues. Our results demonstrate lipophilin B gene and protein upregulation in ovarian carcinoma compared to normal ovary. Moreover, lipophilin B gene overexpression correlates with a less aggressive tumor phenotype and represents a novel ovarian carcinoma prognostic factor.
Twelves D, Nerurkar A, Osin P, et al.DNA promoter hypermethylation profiles in breast duct fluid.
Breast Cancer Res Treat. 2013; 139(2):341-50 [PubMed
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DNA methylation of tumor-suppressor genes occurs early in the molecular transformation of precursor events to breast cancer and is therefore of interest to screening in high-risk women. The aim of this study was to use tumor-suppressor genes that have previously been shown to be cancer predictive in tissue to evaluate the potential of DNA methylation assays in cells from duct lavage (DL) fluid. The frequency of target gene DNA methylation in tissue and DL of cancer and healthy control patients was assessed, and an association of DNA methylation between different duct systems in the same breast was explored. The cancer and control groups were identified in the outpatient clinic when surgical treatment was finalized. Tumor, adjacent tissue and bilateral DL samples for comparative DNA methylation studies were obtained during surgery from women with cancer. In the healthy control group, samples of tissue and DL were collected. Reverse transcriptase methylation-specific PCR was conducted on modified DNA purified from 42 cancer biopsies, 41 benign excision cavity biopsies (internal control), 29 benign biopsies (external control), and 119 DL specimens. A validated panel of cancer predictive genes was analyzed in the study bank of tissue and DL samples from cancer and healthy patients. The sensitivity of DNA methylation in DL samples compared with matched cancer tissue was highest for SCGB3A1 (90 %), CDH13 (91 %), and RARB (83 %). The genetic algorithm selected RASSF1A, RARB, and IGFBP7 as the optimum predictor set for detecting DNA methylation in cancer tissue. The optimum area under the ROC curve for DNA methylation in cancer compared with internal control healthy tissue from excision margins was 0.84. The area under the ROC curve for DNA methylation in cancer DL compared with contralateral benign DL was 0.76. DL cytology was not a helpful predictor of breast cancer. This study shows that relative patterns of tumor-suppressor gene hypermethylation in breast cancer tissue are significantly reflected in the DL from the cancer affected breast. Using DL, nonconcordant patterns of DNA methylation between different duct systems confer independent oncologic potential for distinct breast lobes. The approach of DNA methylation in DL may be substantiated by a larger trial of breast cancer biomarkers.
García-Baquero R, Puerta P, Beltran M, et al.Methylation of a novel panel of tumor suppressor genes in urine moves forward noninvasive diagnosis and prognosis of bladder cancer: a 2-center prospective study.
J Urol. 2013; 190(2):723-30 [PubMed
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PURPOSE: Changes in DNA methylation of tumor suppressor genes early in carcinogenesis represent potential indicators of cancer detection and disease evolution. We examined the diagnostic, stratification and prognostic biomarker roles in urine of the methylation of a novel panel of tumor suppressor genes in bladder cancer.
MATERIAL AND METHODS: We evaluated the methylation of 18 tumor suppressor genes in 2 prospective, independent sets of urine samples (training set of 120 preparations and validation set of 128) from patients with bladder cancer (170) and controls (78) using methylation specific multiplex ligation-dependent probe amplification. Diagnostic performance was evaluated with ROC curves. Recurrence, progression and disease specific survival were analyzed using univariate and multivariate Cox models.
RESULTS: PRDM2, HLTF, ID4, DLC1, BNIP3, H2AFX, CACNA1G, TGIF and CACNA1A were methylated in bladder cancer. CCND2, SCGB3A1, BNIP3, ID4 and RUNX3 were the most frequently methylated tumor suppressor genes in each urine set. Methylation of several tumor suppressor genes correlated with clinicopathological variables, such as stage, tumor grade, focality or age. ROC analysis revealed significant diagnostic accuracy for RUNX3 and CACNA1A in the training set, and for RUNX3 and ID4 in the validation set. On univariate and multivariate analysis CACNA1A methylation correlated with recurrence in the training set, while in the validation set PRDM2 and BNIP3 were significantly associated with recurrence and disease specific survival, respectively.
CONCLUSIONS: Tumor suppressor gene methylation allowed for histopathological and clinical stratification. Urine methylation has noninvasive usefulness not only for diagnostic assessment but also as independent bladder cancer prognosticators.
Verschuur-Maes AH, de Bruin PC, van Diest PJEpigenetic progression of columnar cell lesions of the breast to invasive breast cancer.
Breast Cancer Res Treat. 2012; 136(3):705-15 [PubMed
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Promoter hypermethylation of several tumour suppressor genes often occurs during breast carcinogenesis, but little is known about epigenetic silencing in the possible precursor columnar cell lesion (CCL). Promoter hypermethylation of 50 different tumour suppressor genes was assessed in normal breast tissue (N = 10), CCL (N = 15), ductal carcinoma in situ (DCIS) grade I originating in CCL (N = 5) and paired CCL (N = 15) with DCIS (N = 7) and/or invasive carcinoma (N = 14) by Methylation-specific multiplex ligation-dependent probe amplification. Increasing mean cumulative methylation levels were found from normal breast tissue to CCL to DCIS and invasive carcinoma (P < 0.001) with similar methylation levels in DCIS and invasive carcinoma. Methylation levels and frequencies (in the overall analysis and analysis of only the synchronous lesions) were the highest for RASSF1, CCND2, ID4, SCGB3A1 and CDH13. The methylation levels of ID4, CCND2, and CDH13 increased significantly from normal breast tissue to CCL and to DCIS/invasive carcinoma. RASSF1, SCGB3A1 and SFRP5 had significant higher methylation levels in CCL compared to normal breast tissue, but showed no significant differences between CCL, DCIS and invasive carcinoma. Also, no difference was found between CCLs with and without atypia, or CCLs with or without synchronous cancer. In conclusion, promoter hypermethylation for several established tumour suppressor genes is already present in CCLs, underlining that promoter hypermethylation is an early event in breast carcinogenesis. Atypia in CCL or the presence of synchronous more advanced lesions does not seem to be accompanied by higher methylation levels.
Kim GE, Kweon SS, Lee JS, et al.Quantitative assessment of DNA methylation for the detection of cervical and endometrial adenocarcinomas in liquid-based cytology specimens.
Anal Quant Cytopathol Histpathol. 2012; 34(4):195-203 [PubMed
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OBJECTIVE: To investigate the aberrant promoter hypermethylation as a screening tool for cervical adenocarcinomas (CAs) and endometrial adenocarcinomas (EAs) in cervical scrapings.
STUDY DESIGN: A quantitative multiplex methylation-specific polymerase chain reaction approach was used to examine promoter methylation of 5 genes (APC, HIN-1, RAR-beta, RASSF1A and Twist) in biopsy-confirmed CA (n = 31) and EA (n = 27) residual, liquid-based cytology samples. The data of negative for intraepithelial lesions or malignancy and low-grade squamous intraepithelial lesions were used as controls.
RESULTS: Methylation levels of APC, RAR-beta, RASSF1A and Twist were significantly higher in CA than in control cervical samples. For EA, only the methylation levels of RASSF1A differed significantly from those of control. Receiver-operating characteristic analysis demonstrated that APC, RAR-beta and RASSF1A had the ability to distinguish CA/EA, CA and EA from control samples. In CA/EA and CA samples, the best 3-gene combination was RASSF1A/RAR-beta/APC. This 3-gene panel had a sensitivity of 87.0% for CA/EA and of 80.6% for CA and a specificity of 79.3% for both CA/EA and CA. In EA samples, RASSF1A showed the best performance in distinguishing EA from control. The estimated sensitivity of RASSF1A for detecting EA was 63.0%, and its specificity was 96.3%.
CONCLUSION: This feasibility study demonstrates that quantitative detection of aberrant DNA methylation in cervical scrapings may be a promising new diagnostic tool for the detection of CA and EA.
Sturgeon SR, Balasubramanian R, Schairer C, et al.Detection of promoter methylation of tumor suppressor genes in serum DNA of breast cancer cases and benign breast disease controls.
Epigenetics. 2012; 7(11):1258-67 [PubMed
] Free Access to Full Article Related Publications
Tumors are capable of shedding DNA into the blood stream. This shed DNA may be recovered from serum or plasma. The objective of this study was to evaluate whether pyrosequencing promoter DNA in a panel of 12 breast cancer-related genes (APC, BRCA1, CCND2, CDH1, ESR1, GSTP1, HIN1, P16, RARβ, RASSF1, SFRP1 and TWIST) to measure the degree of methylation would lead to a useful serum-based marker of breast cancer. Serum was obtained from women who were about to undergo a breast biopsy or mastectomy at three hospitals from 1977 to 1987 in Grand Rapids, MI USA. We compared the methylation status of 12 genes in serum DNA obtained from three groups of postmenopausal women (mean age at blood collection: 63.0 y; SD 9.9; range 35-91): breast cancer cases with lymph node-positive disease (n = 241); breast cancer cases with lymph node-negative disease (n = 63); and benign breast disease control subjects (n = 234). Overall, median levels of promoter methylation were low, typically below 5%, for all genes in all study groups. For all genes, median levels of methylation were higher (by 3.3 to 47.6%) in lymph node-positive breast cancer cases than in the controls. Comparing mean methylation level between lymph-node positive cases and controls, the most statistically significant findings, after adjustment of the false-positive rate (q-value), were for TWIST (p = 0.04), SFRP1 (p = 0.16), ESR1 (p = 0.17), P16 (p = 0.19) and APC (p = 0.19). For two of these four genes (TWIST, P16), the median methylation level was also highest in lymph-node positive cases, intermediate in lymph node-negative cases and lowest in the controls. The percent of study subjects with mean methylation scores ≥ 5% was higher among lymph node-positive cases than controls for ten genes, and significantly higher for HIN1 and TWIST (22.0 vs. 12.2%, p = 0.04 and 37.9 vs. 24.5%, p = 0.004, respectively). Despite relatively consistent variation in methylation patterns among groups, these modest differences did not provide sufficient ability to distinguish between cases and controls in a clinical setting.
BACKGROUND: This study is to analyze promoter methylation of various tumor suppressor genes in different types of ovarian carcinoma and to identify potential therapeutic targets of ovarian clear cell adenocarcinoma (OCCA).
MATERIALS AND METHODS: The promoter methylation statuses of 40 genes in primary ovarian carcinomas including 47 clear- and 63 non-clear-cell type tissues, 6 OCCA cell lines, 29 benign ovarian endometriotic cysts, and 31 normal controls were analyzed by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). The MS-MLPA results were correlated with clinicopathological features and outcomes of 47 OCCA patients. Functions of the target genes were further explored by Western Blot Analysis, apoptosis assay, and caspase-3/7 activity analysis.
RESULTS: Frequencies of methylated RASSF1A, CDH13, CACNA1A, HIN-1, and sFRP5 genes in OCCA tissues were significantly higher than those in non-OCCA cancerous tissues and benign endometriotic cysts. The expected OS for patients with methylated promoters of HIN-1 was significantly worse than those for patients without methylated HIN-1 (30% vs. 62%, p = 0.002). The HIN-1 gene was over-expressed in ES2 cells, a significant reduction in cell growth and induction of apoptosis, and increasing paclitaxel sensitivity by reducing phosphorylation of Akt were observed.
CONCLUSIONS: Methylation of HIN-1 promoter is a novel epigenetic biomarker associated with poor outcomes in OCCA patients. Ectopic expression of the HIN-1 gene increased paclitaxel sensitivity which is partly through Akt pathway.
Epigenetic aberrations and a CpG island methylator phenotype are associated with poor outcome in children with neuroblastoma (NB). Previously, we have shown that valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, exerts antitumor effects in an NB xenograft model. However, the underlying antitumor molecular mechanisms are largely unknown. In this study, we examined the role of HDAC in cell proliferation, cell cycle progression, gene expression patterns, and epigenome in NB. Cell proliferation, cell cycle progression, caspase activity, RNA and protein expression, quantitative methylation, and global DNA methylation were examined in NBL-W-N and LA1-55n NB cell lines. Our studies showed that inhibition of HDAC decreased NB proliferation, and induced caspase activity and G1 growth arrest. Expression patterns of cancer-related genes were modulated by VPA. The expression of THBS1, CASP8, SPARC, CDKN1A, HIC1, CDKN1B, and HIN1 was upregulated, and that of MYCN and TIG1 was downregulated. HDAC inhibition decreased methylation levels of THBS1 and RASSF1A promoters. Inhibition of HDAC increased acetylation of histone 4 and overall DNA methylation levels. Our studies showed that inhibition of HDAC blocked cell proliferation and cell cycle progression in relation to alteration in cancer-related genes, increased overall DNA methylation, and decreased methylation of tumor suppressor genes. Further studies examining the antitumor effects of VPA in NB are warranted.
Fonseca AL, Kugelberg J, Starker LF, et al.Comprehensive DNA methylation analysis of benign and malignant adrenocortical tumors.
Genes Chromosomes Cancer. 2012; 51(10):949-60 [PubMed
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The molecular pathogenesis of benign and malignant adrenocortical tumors (ACT) is incompletely clarified. The role of DNA methylation in adrenocortical tumorigenesis has not been analyzed in an unbiased, systematic fashion. Using the Infinium HumanMethylation27 BeadChip, the DNA methylation levels of 27,578 CpG sites were investigated in bisulfite-modified DNA from 6 normal adrenocortical tissue samples, 27 adrenocortical adenomas (ACA), and 15 adrenocortical carcinomas (ACC). Genes involved in cell cycle regulation, apoptosis, and transcriptional regulation of known or putative importance in the development of adrenal tumors showed significant and frequent hypermethylation. Such genes included CDKN2A, GATA4, BCL2, DLEC1, HDAC10, PYCARD, and SCGB3A1/HIN1. Comparing benign versus malignant ACT, a total of 212 CpG islands were identified as significantly hypermethylated in ACC. Gene expression studies of selected hypermethylated genes (CDKN2A, GATA4, DLEC1, HDAC10, PYCARD, SCGB3A1/HIN1) in 6 normal and 16 neoplastic adrenocortical tissues (10 ACA and 6 ACC), displayed reduced gene expression in benign and malignant ACT versus normal adrenocortical tissue. Treatment with 5-aza-2'-deoxycytidine of adrenocortical cancer H-295R cells increased expression of the hypermethylated genes CDKN2A, GATA4, DLEC1, HDAC10, PYCARD, and SCGB3A1/HIN1. In conclusion, the current study represents the first unbiased, quantitative, genome-wide study of adrenocortical tumor DNA methylation. Genes with altered DNA methylation patterns were identified of putative importance to benign and malignant adrenocortical tumor development.
Wang S, Dorsey TH, Terunuma A, et al.Relationship between tumor DNA methylation status and patient characteristics in African-American and European-American women with breast cancer.
PLoS One. 2012; 7(5):e37928 [PubMed
] Free Access to Full Article Related Publications
Aberrant DNA methylation is critical for development and progression of breast cancer. We investigated the association of CpG island methylation in candidate genes and clinicopathological features in 65 African-American (AA) and European-American (EA) breast cancer patients. Quantitative methylation analysis was carried out on bisulfite modified genomic DNA and sequencing (pyrosequencing) for promoter CpG islands of p16, ESR1, RASSF1A, RARβ2, CDH13, HIN1, SFRP1 genes and the LINE1 repetitive element using matched paired non-cancerous and breast tumor specimen (32 AA and 33 EA women). Five of the genes, all known tumor suppressor genes (RASSF1A, RARβ2, CDH13, HIN1 and SFRP1), were found to be frequently hypermethylated in breast tumor tissues but not in the adjacent non-cancerous tissues. Significant differences in the CDH13 methylation status were observed by comparing DNA methylation between AA and EA patients, with more obvious CDH13 methylation differences between the two patient groups in the ER- disease and among young patients (age<50). In addition, we observed associations between CDH13, SFRP1, and RASSF1A methylation and breast cancer subtypes and between SFRP1 methylation and patient's age. Furthermore, tumors that received neoadjuvant therapy tended to have reduced RASSF1A methylation when compared with chemotherapy naïve tumors. Finally, Kaplan Meier survival analysis showed a significant association between methylation at 3 loci (RASSF1A, RARβ2 and CDH13) and reduced overall disease survival. In conclusion, the DNA methylation status of breast tumors was found to be significantly associated with clinicopathological features and race/ethnicity of the patients.
Xu J, Shetty PB, Feng W, et al.Methylation of HIN-1, RASSF1A, RIL and CDH13 in breast cancer is associated with clinical characteristics, but only RASSF1A methylation is associated with outcome.
BMC Cancer. 2012; 12:243 [PubMed
] Free Access to Full Article Related Publications
BACKGROUND: Aberrant promoter CpG island hypermethylation is associated with transcriptional silencing. Tumor suppressor genes are the key targets of hypermethylation in breast cancer and therefore may lead to malignancy by deregulation of cell growth and division. Our previous pilot study with pairs of malignant and normal breast tissues identified correlated methylation of two pairs of genes - HIN-1/RASSFIA and RIL/CDH13 - with expression of estrogen receptors (ER), progesterone receptors (PR), and HER2 (HER2). To determine the impact of methylation on clinical outcome, we have conducted a larger study with breast cancers for which time to first recurrence and overall survival are known.
METHODS: Tumors from 193 patients with early stage breast cancer who received no adjuvant systemic therapy were used to analyze methylation levels of RIL, HIN-1, RASSF1A and CDH13 genes for associations with known predictive and prognostic factors and for impact on time to first recurrence and overall survival.
RESULTS: In this study, we found that ER was associated with RASSF1A methylation (p < 0.001) and HIN-1 methylation (p = 0.002). PR was associated with RIL methylation (p = 0.012), HIN-1 (p = 0.002), and RASSF1A methylation (p = 0.019). Tumor size was associated with RIL and CDH13 methylation (both p = 0.002), and S-phase was associated with RIL methylation (p = 0.036). Only RASSF1A was associated with worse time to first recurrence (p = 0.045) and worse overall survival (p = 0.016) after adjusting for age, tumor size, S-phase, estrogen receptor and progesterone receptor.
CONCLUSIONS: Methylation of HIN-1, RASSF1A, RIL and CDH13 in breast cancers was associated with clinical characteristics, but only RASSF1A methylation was associated with time to first recurrence and overall survival. Our data suggest that RASSF1A methylation could be a potential prognostic biomarker.
Yu Y, Yin D, Hoque MO, et al.AKT signaling pathway activated by HIN-1 methylation in non-small cell lung cancer.
Tumour Biol. 2012; 33(2):307-14 [PubMed
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The purpose of this study is to determine the epigenetic changes and function of High in Normal-1 (HIN-1) in non-small cell lung cancer (NSCLC). HIN-1 expression was examined by semiquantitative RT-PCR before and after 5-aza-2'-deoxycytidine (5-aza) treatment in NSCLC cell lines. Promoter methylation status of HIN-1 was tested by methylation-specific PCR (MSP). Effect of forced expression of HIN-1 on different key molecules of AKT signaling pathway was tested by Western Blot analysis in H157 and H23 cell lines. Promoter methylations are inversely correlated with expression of HIN-1 in eight (H23, H157, 95D, H1299, H358, H1752, H460, A549) of ten NSCLC cell lines and re-expression was observed by 5-aza treatment. We then tested promoter methylation of HIN-1 in primary NSCLC tissues. Methylation was detected in 73 out of 152 (48%) NSCLC cases. Forced expression of HIN-1 in NSCLC cell lines inhibited colony formation and induce apoptosis. Furthermore, overexpression of HIN-1 reduces the expression of phosphorated-AKT (p-AKT), c-myc, Bcl-2 and cyclinD1 while Bax was increased. Our data suggest that HIN-1 is a potential tumor suppressor gene in NSCLC, silenced by promoter hypermethylation and negatively regulate AKT signaling pathway.
Abnormal methylation in gene promoters is a hallmark of the cancer genome; however, factors that may influence promoter methylation have not been well elucidated. As the one-carbon metabolism pathway provides the universal methyl donor for methylation reactions, perturbation of this pathway might influence DNA methylation and, ultimately, affect gene functions. Utilizing approximately 800 breast cancer tumor tissues from a large population-based study, we investigated the relationships between dietary and genetic factors involved in the one-carbon metabolism pathway and promoter methylation of a panel of 13 breast cancer-related genes. We found that CCND2, HIN1 and CHD1 were the most "dietary sensitive" genes, as methylation of their promoters was associated with intakes of at least two out of the eight dietary methyl factors examined. On the other hand, some micronutrients (i.e., B 2 and B 6) were more "epigenetically active" as their intake levels correlated with promoter methylation status in 3 out of the 13 breast cancer genes evaluated. Both positive (hypermethylation) and inverse (hypomethylation) associations with high micronutrient intake were observed. Unlike what we saw for dietary factors, we did not observe any clear patterns between one-carbon genetic polymorphisms and the promoter methylation status of the genes examined. Our results provide preliminary evidence that one-carbon metabolism may have the capacity to influence the breast cancer epigenome. Given that epigenetic alterations are thought to occur early in cancer development and are potentially reversible, dietary modifications may offer promising venues for cancer intervention and prevention.
Park SY, Kwon HJ, Choi Y, et al.Distinct patterns of promoter CpG island methylation of breast cancer subtypes are associated with stem cell phenotypes.
Mod Pathol. 2012; 25(2):185-96 [PubMed
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Although DNA methylation profiles in breast cancer have been connected to breast cancer molecular subtype, there have been no studies of the association of DNA methylation with stem cell phenotype. This study was designed to evaluate the promoter CpG island methylation of 15 genes in relation to breast cancer subtype, and to investigate whether the patterns of CpG island methylation in each subtype are associated with their cancer stem cell phenotype represented by CD44+/CD24- and ALDH1 expression. We performed MethyLight analysis of the methylation status of 15 promoter CpG island loci involved in breast cancer progression (APC, DLEC1, GRIN2B, GSTP1, HOXA1, HOXA10, IGF2, MT1G, RARB, RASSF1A, RUNX3, SCGB3A1, SFRP1, SFRP4, and TMEFF2) and determined cancer stem cell phenotype by CD44/CD24 and ALDH1 immunohistochemistry in 36 luminal A, 33 luminal B, 30 luminal-HER2, 40 HER2 enriched, and 40 basal-like subtypes of breast cancer. The number of CpG island loci methylated differed significantly between subtypes, and was highest in the luminal-HER2 subtype and lowest in the basal-like subtype. Methylation frequencies and levels in 12 of the 15 genes differed significantly between subtypes, and the basal-like subtype had significantly lower methylation frequencies and levels in nine of the genes than the other subtypes. CD44+/CD24- and ALDH1+ putative stem cell populations were most enriched in the basal-like subtype. Methylation of promoter CpG islands was significantly lower in CD44+/CD24-cell (+) tumors than in CD44+/CD24-cell (-) tumors, even within the basal-like subtype. ALDH1 (+) tumors were also less methylated than ALDH1 (-) tumors. Our findings showed that promoter CpG island methylation was different in relation to breast cancer subtype and stem cell phenotype of tumor, suggesting that breast cancers have distinct patterns of CpG island methylation according to molecular subtypes and these are associated with different stem cell phenotypes of the tumor.
The association between promoter methylation status and survival was investigated in a large cohort of women with breast cancer, participants in the Long Island Breast Cancer Study Project. Archived tumor tissues (n = 839) were collected from women diagnosed with a first primary invasive or in situ breast cancer in 1996-1997. Vital status was followed through the end of 2005 with a mean follow-up time of 8 years. Promoter methylation of eight breast cancer-related genes was assessed by MethyLight. The frequencies of methylation for HIN1, RASSF1A, DAPK1, GSTP1, CyclinD2, TWIST, CDH1 and RARβ were 62.9, 85.2, 14.1, 27.8, 19.6, 15.3, 5.8 and 27.6%, respectively. Since survival rates of in situ and invasive breast cancers are substantially different, survival analyses were conducted within 670 invasive cases with complete data on all genes. Age-adjusted Cox proportional hazards models revealed that GSTP1, TWIST and RARβ methylation was significantly associated with higher breast cancer-specific mortality. Methylation of GSTP1 and RARβ was significantly associated with higher all-cause mortality. To investigate the relationship between the number of methylated genes and breast cancer-specific mortality, we included previously published MethyLight data on p16 and APC methylation status. Breast cancer-specific mortality increased in a dose-dependent manner with increasing number of methylated genes (P (trend) = 0.002), although confidence intervals were wide. Our results suggest that promoter methylation, particularly for a panel of genes, has the potential to be used as a biomarker for predicting prognosis in breast cancer.
BACKGROUND: High serum levels of estradiol are associated with increased risk of postmenopausal breast cancer. Little is known about the gene expression in normal breast tissue in relation to levels of circulating serum estradiol.
METHODS: We compared whole genome expression data of breast tissue samples with serum hormone levels using data from 79 healthy women and 64 breast cancer patients. Significance analysis of microarrays (SAM) was used to identify differentially expressed genes and multivariate linear regression was used to identify independent associations.
RESULTS: Six genes (SCGB3A1, RSPO1, TLN2, SLITRK4, DCLK1, PTGS1) were found differentially expressed according to serum estradiol levels (FDR = 0). Three of these independently predicted estradiol levels in a multivariate model, as SCGB3A1 (HIN1) and TLN2 were up-regulated and PTGS1 (COX1) was down-regulated in breast samples from women with high serum estradiol. Serum estradiol, but none of the differentially expressed genes were significantly associated with mammographic density, another strong breast cancer risk factor. In breast carcinomas, expression of GREB1 and AREG was associated with serum estradiol in all cancers and in the subgroup of estrogen receptor positive cases.
CONCLUSIONS: We have identified genes associated with serum estradiol levels in normal breast tissue and in breast carcinomas. SCGB3A1 is a suggested tumor suppressor gene that inhibits cell growth and invasion and is methylated and down-regulated in many epithelial cancers. Our findings indicate this gene as an important inhibitor of breast cell proliferation in healthy women with high estradiol levels. In the breast, this gene is expressed in luminal cells only and is methylated in non-BRCA-related breast cancers. The possibility of a carcinogenic contribution of silencing of this gene for luminal, but not basal-like cancers should be further explored. PTGS1 induces prostaglandin E2 (PGE2) production which in turn stimulates aromatase expression and hence increases the local production of estradiol. This is the first report studying such associations in normal breast tissue in humans.
Aberrant DNA methylation plays a pivotal role in carcinogenesis and its mapping is likely to provide biomarkers for improved diagnostic and risk assessment in prostate cancer (PCa). We quantified and compared absolute methylation levels among 28 candidate genes in 48 PCa and 29 benign prostate hyperplasia (BPH) samples using the pyrosequencing (PSQ) method to identify genes with diagnostic and prognostic potential. RARB, HIN1, BCL2, GSTP1, CCND2, EGFR5, APC, RASSF1A, MDR1, NKX2-5, CDH13, DPYS, PTGS2, EDNRB, MAL, PDLIM4, HLAa, ESR1 and TIG1 were highly methylated in PCa compared to BPH (p < 0.001), while SERPINB5, CDH1, TWIST1, DAPK1, THRB, MCAM, SLIT2, CDKN2a and SFN were not. RARB methylation above 21% completely distinguished PCa Separation based on methylation level of SFN, SLIT2 and SERPINB5 distinguished low and high Gleason score cancers, e.g. SFN and SERPINB5 together correctly classified 81% and 77% of high and low Gleason score cancers respectively. Several genes including CDH1 previously reported as methylation markers in PCa were not confirmed in our study. Increasing age was positively associated with gene methylation (p < 0.0001).Accurate quantitative measurement of gene methylation in PCa appears promising and further validation of genes like RARB, HIN1, BCL2, APC and GSTP1 is warranted for diagnostic potential and SFN, SLIT2 and SERPINB5 for prognostic potential.
Cigarette smoke creates a molecular field of injury in epithelial cells that line the respiratory tract. We hypothesized that transcriptome sequencing (RNA-Seq) will enhance our understanding of the field of molecular injury in response to tobacco smoke exposure and lung cancer pathogenesis by identifying gene expression differences not interrogated or accurately measured by microarrays. We sequenced the high-molecular-weight fraction of total RNA (>200 nt) from pooled bronchial airway epithelial cell brushings (n = 3 patients per pool) obtained during bronchoscopy from healthy never smoker (NS) and current smoker (S) volunteers and smokers with (C) and without (NC) lung cancer undergoing lung nodule resection surgery. RNA-Seq libraries were prepared using 2 distinct approaches, one capable of capturing non-polyadenylated RNA (the prototype NuGEN Ovation RNA-Seq protocol) and the other designed to measure only polyadenylated RNA (the standard Illumina mRNA-Seq protocol) followed by sequencing generating approximately 29 million 36 nt reads per pool and approximately 22 million 75 nt paired-end reads per pool, respectively. The NuGEN protocol captured additional transcripts not detected by the Illumina protocol at the expense of reduced coverage of polyadenylated transcripts, while longer read lengths and a paired-end sequencing strategy significantly improved the number of reads that could be aligned to the genome. The aligned reads derived from the two complementary protocols were used to define the compendium of genes expressed in the airway epithelium (n = 20,573 genes). Pathways related to the metabolism of xenobiotics by cytochrome P450, retinol metabolism, and oxidoreductase activity were enriched among genes differentially expressed in smokers, whereas chemokine signaling pathways, cytokine-cytokine receptor interactions, and cell adhesion molecules were enriched among genes differentially expressed in smokers with lung cancer. There was a significant correlation between the RNA-Seq gene expression data and Affymetrix microarray data generated from the same samples (P < 0.001); however, the RNA-Seq data detected additional smoking- and cancer-related transcripts whose expression was were either not interrogated by or was not found to be significantly altered when using microarrays, including smoking-related changes in the inflammatory genes S100A8 and S100A9 and cancer-related changes in MUC5AC and secretoglobin (SCGB3A1). Quantitative real-time PCR confirmed differential expression of select genes and non-coding RNAs within individual samples. These results demonstrate that transcriptome sequencing has the potential to provide new insights into the biology of the airway field of injury associated with smoking and lung cancer. The measurement of both coding and non-coding transcripts by RNA-Seq has the potential to help elucidate mechanisms of response to tobacco smoke and to identify additional biomarkers of lung cancer risk and novel targets for chemoprevention.
AIM: To clarify the role of high in normal-1 (HIN-1) gene promoter methylation during gastric cancer development.
METHODS: Gastric cancer cell lines and tissue specimens were analyzed for expression of HIN-1 mRNA and protein using the semi-quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The methylation of the HIN-1 gene promoter was detected in gastric carcinoma cells and tissues using methylation-specific polymerase chain reaction. The 3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium cell viability assay and flow cytometry were used to assess the changes in behaviors of gastric cancer cells with or without 5-aza-2'-deoxycytidine treatment.
RESULTS: HIN-1 was not expressed in 4 of 5 gastric cancer cell lines. The demethylation reagent 5-aza-2'-deoxycytidine was able to induce or upregulate HIN-1 expression in gastric cancer cell lines, which is associated with reduction of tumor cell viability. Furthermore, methylation of the HIN-1 gene promoter was shown in 57.8% (26/45) of the primary gastric cancer and 42.1% (17/38) of adjacent tissue samples, but was not shown in normal gastric mucosa (0/10). From the clinicopathological data of the patients, methylation of the HIN-1 gene promoter was found to be associated with tumor differentiation (P = 0.000).
CONCLUSION: High methylation of HIN-1 gene promoter results in silence of HIN-1 expression in gastric cancer. 5-aza-2'-deoxycytidine reverses HIN-1 methylation and reduces viability of gastric cancer cells.
Dhir M, Yachida S, Van Neste L, et al.Sessile serrated adenomas and classical adenomas: an epigenetic perspective on premalignant neoplastic lesions of the gastrointestinal tract.
Int J Cancer. 2011; 129(8):1889-98 [PubMed
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The diagnosis of sessile serrated adenomas (SSAs) is challenging, and there is a great deal of interobserver variability amongst pathologists in differentiating SSAs from hyperplastic polyps (HPPs). The aim of this study was (i) to assess the utility of epigenetic changes such as DNA methylation in differentiating SSAs from HPPs and (ii) to identify common methylation based molecular markers potentially useful for early detection of premalignant neoplastic lesions of gastrointestinal tract. A total of 97 primary patient adenoma samples were obtained from The Johns Hopkins Hospital pathology archive with IRB approval and HIPAA compliance. We analyzed the promoter associated CpG island methylation status of 17 genes using nested multiplex methylation specific PCR (MSP). Methylation of CDX2, hMLH1 and TLR2 was detected in SSAs and SSAs with dysplasia but not in HPPs. A subset of genes including EVL, GATAs (4 and 5), HIN-1, SFRPs (1, 2, 4 and 5), SOX17 and SYNE1 were methylated frequently in all premalignant gastrointestinal adenomas including tubular adenomas, villous adenomas, SSAs and SSAs with dysplasia but infrequently in non-premalignant polyps such as HPPs. Methylation of CDX2, hMLH1 and TLR2 may be of diagnostic utility in differentiating, histologically challenging cases of SSAs from HPPs. Genes such as EVL, GATAs, HIN-1, SFRPs, SOX17 and SYNE1, which are frequently methylated in all types of tested premalignant adenomas, may be useful as biomarkers in stool-based strategies for early detection of these adenomas and CRCs in future.
Park SY, Kwon HJ, Lee HE, et al.Promoter CpG island hypermethylation during breast cancer progression.
Virchows Arch. 2011; 458(1):73-84 [PubMed
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This study was designed to evaluate the changes in promoter CpG islands hypermethylation during breast cancer progression from pre-invasive lesions [flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS)] to invasive ductal carcinoma (IDC). We performed MethyLight analysis for the methylation status of 57 promoter CpG island loci in 20 IDCs and their paired normal breast tissues. After selecting 15 CpG island loci showing breast cancer-specific DNA methylation, another set of normal breast tissue (n = 10), ADH/FEA (n = 30), DCIS (n = 35), and IDC (n = 30) of the breast were analyzed for these loci. We found six new methylation markers of breast cancer, namely DLEC1, GRIN2B, HOXA1, MT1G, SFRP4, and TMEFF2, in addition to APC, GSTP1, HOXA10, IGF2, RARB, RASSF1A, RUNX3, SCGB3A1 (HIN-1), and SFRP1. The number of methylated genes increased stepwise from normal breast to ADH/FEA and DCIS, while IDC did not differ from DCIS. Methylation levels and frequencies of APC, DLEC1, HOXA1, and RASSF1A promoter CpG islands were significantly higher in ADH/FEA than in normal breast tissue. GRIN2B, GSTP1, HOXA1, RARB, RUNX3, SFRP1, and TMEFF2 showed higher methylation levels and frequencies in DCIS than in ADH/FEA. DICS and IDC did not differ in the methylation levels or frequencies for most CpG island loci except SFRP1 and HOXA10. Our findings showed that promoter CpG island methylation changed significantly in pre-invasive lesions, and was similar in IDC and DCIS, suggesting that CpG island methylation of tumor-related genes is an early event in breast cancer progression.
Paluszczak J, Krajka-Kuźniak V, Małecka Z, et al.Frequent gene hypermethylation in laryngeal cancer cell lines and the resistance to demethylation induction by plant polyphenols.
Toxicol In Vitro. 2011; 25(1):213-21 [PubMed
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Promoter hypermethylation is one of the mechanisms in the transcriptional inactivation of certain carcinoma - associated genes. In laryngeal cancers hypermethylation of tumor suppressor genes is related to their major risk factors- cigarette smoking and drinking strong alcohols. Since DNA methylation is reversible, modulation of the activity of DNA methyltransferases is an established therapeutic strategy, which can be also applied in cancer chemoprevention. Here, using the MSP procedure, we evaluated the frequency of hypermethylation of RARbeta, RASSF1A, HIN-1, GSTP1, MGMT, VHL and DAPK genes in several laryngeal and other head and neck squamous cell carcinoma cell lines and the effect of various polyphenols on the methylation of RARbeta and MGMT genes in the UT-SCC 42B cell line. Most of the cell lines tested were characterized by the hypermethylation of at least one of the genes analyzed. The most frequently hypermethylated genes were RARbeta and MGMT, while GSTP1 and VHL were not methylated in any of the cell lines. None of the tested compounds, including decitabine used as a reference compound, changed the methylation of RARbeta and MGMT genes. These findings suggest that although hypermethylation of RARbeta and MGMT may be considered as potential epigenetic biomarker, their application as therapeutic/chemopreventive targets requires further studies.
Suijkerbuijk KP, Pan X, van der Wall E, et al.Comparison of different promoter methylation assays in breast cancer.
Anal Cell Pathol (Amst). 2010; 33(3):133-41 [PubMed
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BACKGROUND: Promoter hypermethylation has emerged as a promising cancer biomarker. Currently, a large variety of quantitative and non-quantitative techniques is used to measure methylation in clinical specimens. Here we directly compared three commonly used methylation assays and assessed the influence of tissue fixation, target sequence location and the amount of DNA on their performance.
METHODS: We used Methylation-Specific PCR (MSP), Quantitative Multiplex MSP (QM-MSP) and Methylation-Specific Multiplex Ligation-dependent Probe Amplification (MS-MLPA) to compare methylation of CCND2, SCGB3A1, RARB and RASSF1 on DNA from 40 breast carcinomas.
RESULTS: A comparison between MSP and QM-MSP on the same samples showed a high discrepancy: 20% of tumors that showed no methylation in MSP gave >10% methylation in QM-MSP. In contrast, QM-MSP correlated strongly with MS-MLPA when targeting the same sequence in DNA from paraffin embedded as well as fresh frozen tissue. This correlation declined when target sequences were non-overlapping. In titration experiments, MSP and MS-MLPA performed robust with 10 ng of DNA, while QM-MSP was at least ten-fold more sensitive.
CONCLUSION: Despite the difference in molecular basis, QM-MSP and MS-MLPA showed moderate to strong correlations. In contrast, there was a poor concordance between either of these techniques and non-quantitative MSP. For biological samples with scarce DNA, QM-MSP is the method of choice.
BACKGROUND: Changes in DNA methylation of crucial cancer genes including tumor suppressors can occur early in carcinogenesis, being potentially important early indicators of cancer. The objective of this study was to examine a multiplexed approach to assess the methylation of tumor suppressor genes as tumor stratification and clinical outcome prognostic biomarkers for lung cancer.
METHODS: A multicandidate probe panel interrogated DNA for aberrant methylation status in 18 tumor suppressor genes in lung cancer using a methylation-specific multiplex ligation-dependent probe amplification assay (MS-MLPA). Lung cancer cell lines (n = 7), and primary lung tumors (n = 54) were examined using MS-MLPA.
RESULTS: Genes frequently methylated in lung cancer cell lines including SCGB3A1, ID4, CCND2 were found among the most commonly methylated in the lung tumors analyzed. HLTF, BNIP3, H2AFX, CACNA1G, TGIF, ID4 and CACNA1A were identified as novel tumor suppressor candidates methylated in lung tumors. The most frequently methylated genes in lung tumors were SCGB3A1 and DLC1 (both 50.0%). Methylation rates for ID4, DCL1, BNIP3, H2AFX, CACNA1G and TIMP3 were significantly different between squamous and adenocarcinomas. Methylation of RUNX3, SCGB3A1, SFRP4, and DLC1 was significantly associated with the extent of the disease when comparing localized versus metastatic tumors. Moreover, methylation of HTLF, SFRP5 and TIMP3 were significantly associated with overall survival.
CONCLUSIONS: MS-MLPA can be used for classification of certain types of lung tumors and clinical outcome prediction. This latter is clinically relevant by offering an adjunct strategy for the clinical management of lung cancer patients.
BACKGROUND: Promoter hypermethylation and global hypomethylation in the human genome are hallmarks of most cancers. Detection of aberrant methylation in white blood cells (WBC) has been suggested as a marker for cancer development, but has not been extensively investigated. This study was carried out to determine whether aberrant methylation in WBC DNA can be used as a surrogate biomarker for breast cancer risk.
PATIENTS AND METHODS: Promoter hypermethylation of 8 tumor suppressor genes (RASSF1A, APC, HIN1, BRCA1, CYCLIND2, RARbeta, CDH1 and TWIST1) and DNA methylation for three repetitive elements (LINE1, Sat2 and Alu) were analyzed in invasive ductal carcinoma of the breast, paired adjacent normal tissue and WBC from 40 breast cancer patients by the MethyLight assay. Methylation in WBC from 40 controls was also analyzed.
RESULTS: Tumor and adjacent tissues showed frequent hypermethylation for all genes tested, while WBC DNA was rarely hypermethylated. For HIN1, RASSF1A, APC and TWIST1, there was agreement between hypermethylation in tumor and adjacent tissues (p=0.04, p=0.02, p=0.005 and p<0.0001, respectively). DNA methylation for the three repetitive elements was lower in tumor compared to adjacent tissue and WBC DNA. Significant correlations in the methylation of Sat2M1 between tumor and adjacent tissues and WBC DNA were found (p<0.0001 and p=0.046, respectively). There was also a significant difference in methylation of Sat2M1 between cases and controls (p=0.01).
CONCLUSION: These results suggest that further studies of WBC methylation, including prospective studies, may provide biomarkers of breast cancer risk.
Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths worldwide. The oxygen-sensitive hypoxia inducible factor (HIF) transcriptional regulators HIF-1alpha and HIF-2alpha are overexpressed in many human NSCLCs, and constitutive HIF-2alpha activity can promote murine lung tumor progression, suggesting that HIF proteins may be effective NSCLC therapeutic targets. To investigate the consequences of inhibiting HIF activity in lung cancers, we deleted Hif-1alpha or Hif-2alpha in an established Kras(G12D)-driven murine NSCLC model. Deletion of Hif-1alpha had no obvious effect on tumor growth, whereas Hif-2alpha deletion resulted in an unexpected increase in tumor burden that correlated with reduced expression of the candidate tumor suppressor gene Scgb3a1 (HIN-1). Here, we identify Scgb3a1 as a direct HIF-2alpha target gene and demonstrate that HIF-2alpha regulates Scgb3a1 expression and tumor formation in human Kras(G12D)-driven NSCLC cells. AKT pathway activity, reported to be repressed by Scgb3a1, was enhanced in HIF-2alpha-deficient human NSCLC cells and xenografts. Finally, a direct correlation between HIF-2alpha and SCGB3a1 expression was observed in approximately 70% of human NSCLC samples analyzed. These data suggest that, whereas HIF-2alpha overexpression can contribute to NSCLC progression, therapeutic inhibition of HIF-2alpha below a critical threshold may paradoxically promote tumor growth by reducing expression of tumor suppressor genes, including Scgb3a1.
INTRODUCTION: Metastasis represents a major adverse step in the progression of breast carcinoma. Lymph node invasion is the most relevant prognostic factor; however little is known on the molecular events associated with lymph node metastasis process. This study is to investigate the status and role of methylation in lymph node metastatic tumors.
MATERIALS AND METHODS: Bisulfite pyrosequencing is used to screen 6 putative tumor suppressor genes (HIN-1, RASSF1A, RIL, CDH13, RARbeta2 and E-cadherin) in 38 pairs of primary breast tumors and lymph node metastases.
RESULTS: We found that HIN-1, CDH13, RIL, RASSF1A and RARbeta2 were frequently methylated both in primary and metastatic tissues (range: 55.3% approximately 89.5%). E-cadherin was not frequently methylated in either setting (range: 18.4% approximately 23.7%). The methylation status of HIN-1, CDH13, RIL, and RARbeta2 in lymph nodes metastasis were correlated with that in primary tumors. The Pearson correlation values ranged from 0.624 to 0.472 (p values < 0.01 to 0.001). Interestingly, we observed an association between HIN-1 methylation and hormone status in metastatic lymph nodes. Hypermethylation of HIN-1 in metastasis lymph nodes was significantly associated with expression of ER (odds ratio, 1.070; P = 0.024) and with PR (odds ratio, 1.046; P = 0.026).
CONCLUSIONS: This study suggests that hypermethylation of tumor suppressor genes is extended from primary to metastatic tumors during tumor progression.
BACKGROUND: Colorectal cancer (CRC) is 1 of the leading causes of death in the Western world. CRC develops from premalignant lesions, chiefly colorectal adenomas. Currently, the most accurate and recommended screening method for finding colorectal adenomas is colonoscopy performed on all individuals aged>50 years. However, the costs and risks associated with this procedure are relatively high. The objectives of the current study were to correlate epigenetic alterations that occur in normal rectal mucosa, smoking status, and age with the presence or absence of concomitant colorectal adenomas and to assess the potential clinical value of methylation in normal rectal biopsies as a screening assay for the presence of polyps and, hence, the need for a full colonoscopy.
METHODS: One hundred thirteen normal rectal mucosal biopsies from 113 patients were studied. DNA was extracted, modified with sodium bisulfite, and subjected to real-time quantitative, methylation-specific polymerase chain reaction analysis for the following genes: adenomatous polyposis coli (APC); cadherin 1, type 1, E-cadherin (epithelial) (CDH1); estrogen receptor 1 (ESR1); cytokine high in normal 1 (HIN1); hyperplastic polyposis protein 1 (HPP1); O-6 methylguanine-DNA methyltransferase (MGMT); neural epidermal growth factor-like 1 (NELL1); splicing factor 3B, 14-kDa subunit (p14); cyclin-dependent kinase (CDK) inhibitor 2B (inhibits CDK4) (p15); retinoic acid receptor beta (RARβ); somatostatin (SST); tachykinin, precursor 1 (TAC1); and tissue inhibitor of metalloproteinase (TIMP) metallopeptidase inhibitor 3 (TIMP3). Data were then analyzed using several proprietary software programs.
RESULTS: By using several sets of genes, clinical characteristics, and multivariate analyses, the authors developed a prediction model for the presence of concomitant colorectal adenomas at the time of rectal biopsy. They also observed strong correlations between smoking status and rectal methylation pattern and between smoking status and the presence or risk of concomitant adenomas.
CONCLUSIONS: A prediction model was developed for the presence of colorectal adenomas based on gene methylation patterns in the normal rectum. The results indicated that these genes may be involved in early stages of adenoma formation. The observed epigenetic alterations in these markers may be caused in part by the effects of smoking and/or age. Normal rectal methylation may be useful as a biomarker for narrowing the population in need of screening colonoscopy.