Research IndicatorsGraph generated 01 September 2019 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 01 September, 2019 using data from PubMed, MeSH and CancerIndex
Specific Cancers (3)
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
GEO Profiles, NCBI
Search the gene expression profiles from curated DataSets in the Gene Expression Omnibus (GEO) repository.
Latest Publications: PRDM2 (cancer-related)
The PR/SET domain gene family (PRDM) encodes 19 different transcription factors that share a subtype of the SET domain [Su(var)3-9, enhancer-of-zeste and trithorax] known as the PRDF1-RIZ (PR) homology domain. This domain, with its potential methyltransferase activity, is followed by a variable number of zinc-finger motifs, which likely mediate protein⁻protein, protein⁻RNA, or protein⁻DNA interactions. Intriguingly, almost all PRDM family members express different isoforms, which likely play opposite roles in oncogenesis. Remarkably, several studies have described alterations in most of the family members in malignancies. Here, to obtain a pan-cancer overview of the genomic and transcriptomic alterations of
Taniguchi H, Imai KPRDM14, a Zinc Finger Protein, Regulates Cancer Stemness.
Methods Mol Biol. 2018; 1867:3-13 [PubMed
] Related Publications
PRDI-BF1 and RIZ homology (PR) domain zinc finger protein 14 (PRDM14) contains a PR domain related to the SET methyltransferase domain and zinc finger motifs. PRDM14 maintains stemness in embryonic stem cells and primordial germ cells via epigenetic mechanisms. PRDM14, however, is not expressed in normal differentiated tissues. We and other groups previously reported that PRDM14 expression is markedly higher in some types of cancers compared to the corresponding normal tissues. PRDM14 confers stem cell-like characteristics upon cancer cells, such as sphere formation, dye efflux, chemotherapy resistance, proliferation, and distant metastasis. Cancer stem cells (CSCs) are thought to be responsible for tumor initiation, drug and radiation resistance, invasive growth, metastasis, and tumor relapse, which are the primary causes of cancer-related deaths. Because CSCs are also thought to be resistant to conventional therapies, an effective and novel therapeutic approach for CSCs is imperative.RNAi silencing of PRDM14 expressed by breast and pancreatic cancer cells reduced tumor size and distant metastasis of these cells in nude mice. Inhibition of PRDM14 expression by cancer cells may be an effective and radical therapy for solid cancers. In this chapter, we discuss methods for studying CSC-like properties in cancer cells and describe the use of siRNA with a drug delivery system by systemic injection in vivo.
Chang YS, Chang CC, Huang HY, et al.Detection of Molecular Alterations in Taiwanese Patients with Medullary Thyroid Cancer Using Whole-Exome Sequencing.
Endocr Pathol. 2018; 29(4):324-331 [PubMed
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Genetic and epigenetic alterations are associated with the progression and prognosis of medullary thyroid carcinoma (MTC). We performed whole-exome sequencing of tumor tissue from seven patients with sporadic MTC using an Illumina HiSeq 2000 sequencing system. We conducted Sanger sequencing to confirm the somatic mutations in both tumor and matched normal tissues. We applied Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis with the Database for Annotation, Visualization, and Integrated Discovery and STRING for pathway analysis. We detected new somatic mutations in the BICD2, DLG1, FSD2, IL17RD, KLHL25, PAPPA2, PRDM2, PSEN1, SCRN1, and TTC1 genes. We found a somatic mutation in the PDE4DIP gene that had previously been discovered mutated in other tumors but that had not been characterized in MTC. We investigated pathway deregulation in MTC. Data regarding 1152 MTCs were assembled from the Catalogue of Somatic Mutations in Cancer (COSMIC) and seven of our patients. Ontological analysis revealed that most of the variants aggregated in pathways that included the signaling pathways of thyroid cancer, central carbon metabolism, microRNAs in cancer, PI3K-Akt, ErbB, MAPK, mTOR, VEGF, and RAS. In conclusion, we conducted wide-ranging exome-wide analysis of the mutational spectrum of MTC in Taiwan's population and detected novel genes with potential associations with MTC tumorigenesis and irregularities in pathways that resulted in MTC pathogenesis.
PR (PRDI‑BFI and RIZ) domain containing (PRDM) proteins have been shown to be important in several types of human cancer. PRDM13, a member of the PRDM family, contains transcriptional regulators involved in modulating several cellular processes. However, the function of PRDM13 in glioma remains to be elucidated. The purpose of the present study was to evaluate the expression and effect of PRDM13 on glioma cells. It was found that the expression of PRDM13 was reduced in glioma cells, and the overexpression of PRDM13 significantly decreased the proliferation, migration and invasion of U87 glioma cells. Through validation of RNA‑sequencing analysis, genes regulating cell proliferation and migration were classified from Gene Ontology sources. In addition, PRDM13 was shown to be associated with Rho protein and GTP enzyme activation protein. The over-expression of PRDM13 upregulated deleted in liver cancer 1 (DLC1) to inhibit the proliferation and invasion of U87 cells. In conclusion, PRDM13 decreased the proliferation and invasion of U87 cells, and may be of potential value for glioma therapy.
Yang S, Xing L, Gu L, et al.Combination of RIZ1 Overexpression and Radiotherapy Contributes to Apoptosis and DNA Damage of HeLa and SiHa Cervical Cancer Cells.
Basic Clin Pharmacol Toxicol. 2018; 123(2):137-146 [PubMed
] Related Publications
Although radiotherapy has been widely applied to treating cervical cancer in the clinic, its therapeutic efficacy is often restricted to the radioresistance of cancer cells. Retinoblastoma protein-interacting zinc finger gene 1 (RIZ1) has been suggested as a tumour suppressor gene, whereas its role in cervical cancer with or without radiotherapy has been unclear. In this study, two cervical cancer cell lines, HeLa and SiHa cells, stably transfected with RIZ1 overexpression plasmid were subjected to ionizing radiation, and their survival fractions were calculated by assessing their clonogenic abilities. Our results showed that the forced overexpression of RIZ1 significantly reduced the clonogenic survival rates of both HeLa and SiHa cells exposed to ionizing radiation. By analysing the cell apoptotic status, we found that the RIZ1-overexpressed cervical cancer cells under ionizing radiation were more vulnerable to damage, and more γ-H2AX foci were found in these cells. Furthermore, the volumes of tumour xenografts formed by the RIZ1-overexpressed cells in nude mice under ionizing radiation were smaller than those generated by the control cells. There were more morphological changes, apoptosis cells and lower expression of PCNA in RIZ1-overexpressed tumour tissues of mice after exposure to ionizing radiation. Taken together, our study demonstrates that the overexpression of RIZ1 combined with radiotherapy facilitates apoptosis and DNA damage of cervical cancer cells.
T-cell prolymphocytic leukemia (T-PLL) is an aggressive malignancy with a median survival of the patients of less than two years. Besides characteristic chromosomal translocations, frequent mutations affect the ATM gene, JAK/STAT pathway members, and epigenetic regulators. We here performed a targeted mutation analysis for 40 genes selected from a RNA sequencing of 10 T-PLL in a collection of 28 T-PLL, and an exome analysis of five further cases. Nonsynonymous mutations were identified in 30 of the 40 genes, 18 being recurrently mutated. We identified recurrently mutated genes previously unknown to be mutated in T-PLL, which are SAMHD1, HERC1, HERC2, PRDM2, PARP10, PTPRC, and FOXP1. SAMHD1 regulates cellular deoxynucleotide levels and acts as a potential tumor suppressor in other leukemias. We observed destructive mutations in 18% of cases as well as deletions in two further cases. Taken together, we identified additional genes involved in JAK/STAT signaling (PTPRC), epigenetic regulation (PRDM2), or DNA damage repair (SAMHD1, PARP10, HERC1, and HERC2) as being recurrently mutated in T-PLL. Thus, our study considerably extends the picture of pathways involved in molecular pathogenesis of T-PLL and identifies the tumor suppressor gene SAMHD1 with ~20% of T-PLL affected by destructive lesions likely as major player in T-PLL pathogenesis.
Zhang S, Zhang Q, Sun Q, et al.Genome Evolution Analysis of Recurrent Testicular Malignant Mesothelioma by Whole-Genome Sequencing.
Cell Physiol Biochem. 2018; 45(1):163-174 [PubMed
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BACKGROUND/AIMS: Malignant mesothelioma of the tunica vaginalis testis is a rare and lethal disease. The genomic characteristics and genetic changes of tumor cells during the progression of this disease are unknown.
METHODS: we performed whole-genome sequencing of four successive tumor samples derived from surgery and a blood sample in a single patient.
RESULTS: All tumors were found to have significant C-to-T and T-to-C mutations, and amplification of copy number in chromosomes 1 and 12 were notified in all tumor samples. Subclone analysis revealed a parallel evolution of the tumor in this patient. We also identified some mutations in mesothelioma-associated genes such as KIF25, AHNAK, and PRDM2.
CONCLUSIONS: The results showed a comprehensive genomic change in malignant mesothelioma of the tunica vaginalis testis and provide a better understanding of the clonal evolution during tumor recurrence and metastasis.
Maruvka YE, Mouw KW, Karlic R, et al.Analysis of somatic microsatellite indels identifies driver events in human tumors.
Nat Biotechnol. 2017; 35(10):951-959 [PubMed
] Related Publications
Microsatellites (MSs) are tracts of variable-length repeats of short DNA motifs that exhibit high rates of mutation in the form of insertions or deletions (indels) of the repeated motif. Despite their prevalence, the contribution of somatic MS indels to cancer has been largely unexplored, owing to difficulties in detecting them in short-read sequencing data. Here we present two tools: MSMuTect, for accurate detection of somatic MS indels, and MSMutSig, for identification of genes containing MS indels at a higher frequency than expected by chance. Applying MSMuTect to whole-exome data from 6,747 human tumors representing 20 tumor types, we identified >1,000 previously undescribed MS indels in cancer genes. Additionally, we demonstrate that the number and pattern of MS indels can accurately distinguish microsatellite-stable tumors from tumors with microsatellite instability, thus potentially improving classification of clinically relevant subgroups. Finally, we identified seven MS indel driver hotspots: four in known cancer genes (ACVR2A, RNF43, JAK1, and MSH3) and three in genes not previously implicated as cancer drivers (ESRP1, PRDM2, and DOCK3).
Xue Y, Chen R, Du W, et al.RIZ1 and histone methylation status in pituitary adenomas.
Tumour Biol. 2017; 39(7):1010428317711794 [PubMed
] Related Publications
RIZ1 displays strong tumor-suppressive activities, which has a potential histone methyltransferase activity. The objective of the study was to evaluate the level and the methylation status of RIZ1 and analyze its association with clinicopathological features and the histone in the pituitary adenomas. We found that RIZ1-positive cases were 11/50 and H-Scores 22.75 ± 11.83 in invasive pituitary adenomas and 26/53 and 66.3 ± 21.7 in non-invasive pituitary adenomas (χ
Yang T, Ren C, Jiang A, et al.RIZ1 is regulated by estrogen and suppresses tumor progression in endometrial cancer.
Biochem Biophys Res Commun. 2017; 489(2):96-102 [PubMed
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Endometrial cancer (EC) is the estrogen-dependent gynecologic malignancy, however the molecular mechanism involved in the development and progression of EC remain unclear. The aim of this study was to investigate the role of RIZ1 in EC. Immunohistochemical analysis revealed that RIZ1was decreased in EC than in normal endometrium. Lower RIZ1 level was correlated with high-grade carcinoma (p = 0.048) and positive expression of ERα (p = 0.004). In EC cells, estrogen could down regulated the expression of RIZ1, however, ICI182,780 could up regulated the expression of RIZ1. Besides, in vitro and in vivo, RIZ1 could remarkably suppress tumor proliferation, metastasis and invasion. Our data support that RIZ1 was a novel tumor suppressor and could provide a potential therapeutic target in human EC.
Zhao Z, Hu Y, Shen X, et al.HBx represses RIZ1 expression by DNA methyltransferase 1 involvement in decreased miR-152 in hepatocellular carcinoma.
Oncol Rep. 2017; 37(5):2811-2818 [PubMed
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Hepatitis B virus (HBV) is mainly suspected to promote hepatocellular carcinoma (HCC) development by epigenetic alteration. The HBV X protein (HBx) plays a key role in the molecular pathogenesis of HBV-related HCC. However, the mechanism of HBx-mediated hepatocarcinogenesis remains to be elucidated. RIZ1 gene, a candidate HCC suppressor gene, is frequently found to be hypermethylated and downregulated in HCC. In the present study, we show that the expression of RIZ1 was downregulated in 65% HCC tissues. Decreased expression of RIZ1 was restored by 5'-Aza in MHCC-97H HCC cell lines. HBx recombinant transfection increased DNMT1 expression level and suppressed RIZ1 expression. Moreover, knockdown of DNMT1 by siRNA restored RIZ1 expression in HCC cell SMMC-7721 and reduced methylated CpG sites of RIZ1. ChIP results showed that DNMT1 protein could bind to RIZ1 promoter, and this interaction was further enhanced with the transfected HBX recombinant. Moreover, miR-152 was decreased and involved in upregulation of DNMT1 in HBx transfected cells, at least partly, contributed to the epigenetic inactivation of RIZ1. Taken together, our data found that HBx repressed RIZ1 expression via DNMT1, which offered a new mechanism of RIZ1 inactivation in HCC, except for the widely known DNA methylation. These results enriched the epigenetic mechanism by which HBx contributes to pathogenesis of HBV-HCC.
Cai Z, Zhang C, Zou Y, et al.Tissue thioredoxin-interacting protein expression predicted recurrence in patients with meningiomas.
Int J Clin Oncol. 2017; 22(4):660-666 [PubMed
] Related Publications
BACKGROUND: The redox regulatory protein, thioredoxin-interacting protein (TXNIP), has been confirmed as an important tumor suppressor gene in various types of human cancers. In previous studies, we found that overexpression of tumor suppressor gene RIZ1 in meningiomas can significantly improve the expression of TXNIP by microarray data analysis. Therefore, we hypothesized that TXNIP was associated with the initiation and progression of meningiomas.
METHODS: First, we evaluated the expression of TXNIP and Ki-67 in meningioma tissues from 65 patients using immunohistochemistry. We also analyzed the correlation between TXNIP immunoreactivity and clinicopathological features, as well as patient prognostic factors.
RESULTS: According to immunohistochemistry results, high-grade meningioma tissues had significantly lower expression of TXNIP than benign meningioma tissues (29.31 ± 18.70 vs 74.61 ± 7.51, P < 0.0001). TXNIP and Ki67 were negatively correlated (P < 0.0001). Moreover, the expression of TXNIP was higher in nonrecurrent high-grade meningiomas (P < 0.05). In addition, Kaplan-Meier analysis indicated that expression of TXNIP and Ki-67 was related to recurrence-free time. Multivariate Cox analysis showed that TXNIP expression level was the only independent predictor for meningioma prognosis.
CONCLUSION: Our results demonstrated that high expression of TXNIP indicates a lower pathological grade of meningnioma, and is also associated with longer recurrence-free time. Therefore, TXNIP could be regarded as a potential molecular marker to predict recurrence in patients with meningiomas.
Mori N, Ohwashi-Miyazaki M, Yoshinaga K, et al.Tumor suppressor gene methylation on the short arm of chromosome 1 in chronic myelogenous leukemia.
Eur J Haematol. 2017; 98(5):467-477 [PubMed
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OBJECTIVES: We previously reported loss of heterozygosity on 1p in chronic myelogenous leukemia (CML). We analyzed promoter methylation and mutation of tumor suppressor genes on 1p36 in CML.
METHODS: We performed methylation-specific PCR (MS-PCR) analysis of the PRDM2, RUNX3, and TP73 genes in 61 patients with CML (43 chronic phase, CP; two accelerated phase; and 16 blast crisis, BC). Oxidative MS-PCR, PCR-single-strand conformation polymorphism, and real-time reverse transcriptase PCR were also analyzed. K-562 cells were grown in the presence of 5-Aza-dC and trichostatin A.
RESULTS: Methylation of the PRDM2, RUNX3, and TP73 genes was detected in 24/60 (40%), 21/61 (34%), and 28/60 (47%) patients, respectively. Methylation of all three genes was detected in 19/59 (32%) patients. Methylation was more frequent in BC than in CP. Oxidative MS-PCR analysis detected 5-mC in the PRDM2, RUNX3, and TP73 genes in 10/22 (45%), 15/21 (71%), and 16/26 (62%) samples with methylation detected by MS-PCR, respectively. Decreased expression was observed in several samples with methylation, while no mutations were found in the genes. Treatment of K-562 cells induced growth suppression, demethylation, and reexpression of the PRDM2 and RUNX3 genes.
CONCLUSION: Multiple tumor suppressor genes on 1p were inactivated in CML by methylation.
Rajajeyabalachandran G, Kumar S, Murugesan T, et al.Therapeutical potential of deregulated lysine methyltransferase SMYD3 as a safe target for novel anticancer agents.
Expert Opin Ther Targets. 2017; 21(2):145-157 [PubMed
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INTRODUCTION: SET and MYND domain containing-3 (SMYD3) is a member of the lysine methyltransferase family of proteins, and plays an important role in the methylation of various histone and non-histone targets. Proper functioning of SMYD3 is very important for the target molecules to determine their different roles in chromatin remodeling, signal transduction and cell cycle control. Due to the abnormal expression of SMYD3 in tumors, it is projected as a prognostic marker in various solid cancers. Areas covered: Here we elaborate on the general information, structure and the pathological role of SMYD3 protein. We summarize the role of SMYD3-mediated protein interactions in oncology pathways, mutational effects and regulation of SMYD3 in specific types of cancer. The efficacy and mechanisms of action of currently available SMYD3 small molecule inhibitors are also addressed. Expert opinion: The findings analyzed herein demonstrate that aberrant levels of SMYD3 protein exert tumorigenic effects by altering the epigenetic regulation of target genes. The partial involvement of SMYD3 in some distinct pathways provides a vital opportunity in targeting cancer effectively with fewer side effects. Further, identification and co-targeting of synergistic oncogenic pathways is suggested, which could provide much more beneficial effects for the treatment of solid cancers.
DNA methylation is an epigenetic mechanism in the pathogenesis of hepatocellular carcinoma (HCC). Here, we conducted a systematic meta-analysis to evaluate the contribution of DNA methylation to the risk of HCC. A total of 2109 publications were initially retrieved from PubMed, Web of Science, Cochrane Library, Embase, CNKI and Wanfang literature database. After a four-step filtration, we harvested 144 case-control articles in the meta-analysis. Our results revealed that 24 genes (carcinoma tissues vs adjacent tissues), 17 genes (carcinoma tissues vs normal tissues) and six genes (carcinoma serums vs normal serums) were significantly hypermethylated in HCC. Subgroup meta-analysis by geographical populations showed that six genes (carcinoma tissues vs adjacent tissues) and four genes (carcinoma tissues vs normal tissues) were significantly hypermethylated in HCC. Our meta-analysis identified the correlations between a number of aberrant methylated genes (p16, RASSF1A, GSTP1, p14, CDH1, APC, RUNX3, SOCS1, p15, MGMT, SFRP1, WIF1, PRDM2, DAPK1, RARβ, hMLH1, p73, DLC1, p53, SPINT2, OPCML and WT1) and HCC. Aberrant DNA methylation might become useful biomarkers for the prediction and diagnosis of HCC.
Mir R, Najar IA, Guru S, et al.A deletion polymorphism in the RIZ gene is associated with increased progression of imatinib treated chronic myeloid leukemia patients.
Leuk Lymphoma. 2017; 58(7):1694-1701 [PubMed
] Related Publications
RIZ1 encodes a retinoblastoma (Rb)-interacting zinc finger protein, is commonly lost or expressed at reduced levels in cancer cells. The RIZ1 gene locus commonly undergoes LOH in many cancers. Here, we analyzed Proline insertion-deletion polymorphism at amino acid position 704 in the RIZ1 gene and its association with CML. The RIZ1 pro-704 LOH genotypes were determined by AS-PCR in 100 CML patients among which 50 were in CP-CML, 25 in AP-CML, and 25 in BC-CML. Pro704 ins/del polymorphism (LOH) was detected in 27% CML patients. Proline ins-ins homozygosity, del-del homozygosity and ins-del heterozygosity was detected in 9%, 18%, and 73% CML patients compared with 3%, 3%, and 94% in healthy controls, respectively (p < .0003). A four-fold increased risk was found to be associated del-del genotype. We found a statistically significant association between RIZ1 LOH and stage (p > .01) and hematological resistance (p > .001). However, there were no correlations found with other clinical parameters like age, gender, thrombocytopia, type of BCR-ABL, and molecular response. Our findings suggest that proline 704 del-del homozygosity phenotype can play an important role in progression of CML.
Zhang C, Meng W, Wang J, et al.Methylation Status of the RIZ1 Gene Promoter in Human Glioma Tissues and Cell Lines.
Cell Mol Neurobiol. 2017; 37(6):1021-1027 [PubMed
] Related Publications
Retinoblastoma protein-interacting zinc-finger gene 1 (RIZ1), a strong tumor suppressor, is silenced in many human cancers. Our previous studies showed that RIZ1 expression was negatively correlated with the grade of glioma and was a key predictor of patient survival. Therefore, RIZ1 could be a potential tumor suppressor during glioma pathogenesis, although the mechanism underlying RIZ1 gene inactivation in gliomas is unknown. We investigated the methylation status of the RIZ1 promoter in human glioma tissues and four glioblastoma (GBM) cell lines, and verified the effect of the methyltransferase inhibitor 5-aza-2-deoxycytidine (5-aza-CdR) on RIZ1 transcription and cell proliferation. Methylation-specific PCR (MSP) was performed to determine RIZ1 promoter methylation in human glioma specimens. The correlation between RIZ1 hypermethylation in tumors and clinicopathological features also was analyzed. 5-Aza-CdR treatment was used to reactivate gene expression silenced by hypermethylation in the U87 glioblastoma cell line, and real-time PCR was then used to measure RIZ1 expression. The ability of 5-aza-CdR to inhibit the proliferation of glioma cell lines whose RIZ1 promoters were hypermethylated was measured by bromodeoxyuridine (BrdU) incorporation. Among 51 human glioma specimens, RIZ1 promoter methylation was detected in 23 cases. Clinicopathological evaluation suggested that RIZ1 hypermethylation was negatively associated with tumor grade and patient age (P < 0.05). Hypermethylation of the RIZ1 promoter was detected in the U87 and U251 cell lines. RIZ1 mRNA expression in U87 cells was upregulated after treatment with 5-aza-Cdr, which correlated with inhibition of cell proliferation in a time- and concentration-dependent manner. Promoter hypermethylation may play an important role in the epigenetic silencing of RIZ1 expression in human glioma tissues and GBM cell lines.
Cheng HY, Zhang T, Qu Y, et al.Synergism between RIZ1 gene therapy and paclitaxel in SiHa cervical cancer cells.
Cancer Gene Ther. 2016; 23(11):392-395 [PubMed
] Related Publications
RIZ1 is a tumor suppressor gene. The purpose of the present study was to investigate the inhibitory effect of RIZ1 gene therapy on the growth of SiHa cervical cancer cells and its synergism with paclitaxel. The expression levels of RIZ1 were examined by real-time PCR and western blotting before and after transfection of RIZ1. The effects of paclitaxel or pcDNA3.1(+)-RIZ1 alone or in combination, on the proliferation of SiHa cells were evaluated by MTT method. The inhibitory effect on the proliferation of SiHa cells was more significant in the pcDNA3.1(+)-RIZ1 combined with paclitaxel group than in the pcDNA3.1(+)-RIZ1 or paclitaxel groups (P<0.05). The expression level of RIZ1 in SiHa cells increased after treatment with paclitaxel, which indicated a synergism between them. RIZ1 gene therapy combined with paclitaxel showed stronger cell inhibition than paclitaxel alone, which indicated a synergism between them.
Riz I, Hawley TS, Marsal JW, Hawley RGNoncanonical SQSTM1/p62-Nrf2 pathway activation mediates proteasome inhibitor resistance in multiple myeloma cells via redox, metabolic and translational reprogramming.
Oncotarget. 2016; 7(41):66360-66385 [PubMed
] Free Access to Full Article Related Publications
Multiple Myeloma (MM) is a B-cell malignancy characterized by the accumulation of clonal plasma cells in the bone marrow, with drug resistance being a major cause of therapeutic failure. We established a carfilzomib-resistant derivative of the LP-1 MM cell line (LP-1/Cfz) and found that the transcription factor NF-E2 p45-related factor 2 (Nrf2; gene symbol NFE2L2) contributes to carfilzomib resistance. The mechanism of Nrf2 activation involved enhanced translation of Nrf2 as well as its positive regulator, the autophagy receptor sequestosome 1 (SQSTM1)/p62. The eukaryotic translation initiation factor gene EIF4E3 was among the Nrf2 target genes upregulated in LP-1/Cfz cells, suggesting existence of a positive feedback loop. In line with this, we found that siRNA knockdown of eIF4E3 decreased Nrf2 protein levels. On the other hand, elevated SQSTM1/p62 levels were due at least in part to activation of the PERK-eIF2α pathway. LP-1/Cfz cells had decreased levels of reactive oxygen species as well as elevated levels of fatty acid oxidation and prosurvival autophagy. Genetic and pharmacologic inhibition of the Nrf2-EIF4E3 axis or the PERK-eIF2α pathway, disruption of redox homeostasis or inhibition of fatty acid oxidation or autophagy conferred sensitivity to carfilzomib. Our findings were supported by clinical data where increased EIF4E3 expression was predictive of Nrf2 target gene upregulation in a subgroup of patients with chemoresistant minimal residual disease and relapsed/refractory MM. Thus, our data offer a preclinical rationale for including inhibitors of the SQSTM1/p62-Nrf2 pathway to the treatment regimens for certain advanced stage MM patients.
BACKGROUND: Retinoblastoma protein-interacting zinc-finger gene 1 (RIZ1) displays strong tumor suppressive activities, and its expression is often silenced in many types of human tumors. However, the relationship between RIZ1 expression and glioma prognosis remains unclear.
METHODS: The dysregulation of RIZ1 was evaluated using real-time polymerase chain reaction, western blot, and immunohistochemical analysis of gliomas from 51 patients. Correlation analysis was performed to examine relationships between RIZ1 immunoreactivity, clinicopathological features, and patient prognosis. Also, human malignant glioma U87 and U251 cell lines were stably transduced with ectogenic RIZ1 using a lentiviral vector to investigate the effects of induced expression of RIZ1 on cell proliferation, cell cycle, and apoptosis.
RESULTS: Real-time polymerase chain reaction and western blot analysis showed that RIZ1 was downregulated in high-grade gliomas compared with low-grade gliomas and normal brain tissue. Immunohistochemistry showed less RIZ1 labeling in high-grade gliomas than in low-grade gliomas. There was a negative correlation between RIZ1 and Ki-67 immunoreactivity. Clinicopathological evaluation revealed that RIZ1 expression was negatively correlated with tumor grade and patient age. Kaplan-Meier survival analysis showed a positive correlation between RIZ1 immunoreactivity level and progression-free and overall survival times. Multivariate analysis showed that high RIZ1 expression was an independent prognostic factor for patients with gliomas. Induced expression of RIZ1 in U87 and U251 cells reduced cell proliferation and increased apoptosis, and cell cycle analysis revealed that a majority of cells were arrested at G2-M. Moreover, transfection with a RIZ1 expression vector increased p53 and caspase-3 expression and decreased p-IKBα and p-AKT protein levels, suggesting that RIZ1 may stimulate p53-mediated apoptosis and inhibit p-IKBα and p-AKT signaling pathways.
CONCLUSIONS: Our results suggest that high RIZ1 labeling is indicative of lower grades of gliomas and is associated with better progression-free and overall survival rates. Therefore, RIZ1 may be a promising therapeutic target for patients with gliomas.
Lee SH, Lee EH, Lee SH, et al.Epigenetic Role of Histone 3 Lysine Methyltransferase and Demethylase in Regulating Apoptosis Predicting the Recurrence of Atypical Meningioma.
J Korean Med Sci. 2015; 30(8):1157-66 [PubMed
] Free Access to Full Article Related Publications
Alteration of apoptosis is related with progression and recurrence of atypical meningiomas (AMs). However, no comprehensive study has been conducted regarding histone modification regulating apoptosis in AMs. This study aimed to determine the prognostic values of certain apoptosis-associated factors, and examine the role of histone modification on apoptosis in AMs. The medical records of 67 patients with AMs, as diagnosed during recent 13 yr, were reviewed retrospectively. Immunohistochemical staining was performed on archived paraffin-embedded tissues for pro-apoptotic factors (CASP3, IGFBP, TRAIL-R1, BAX, and XAF1), anti-apoptotic factors (survivin, ERK, RAF1, MDM2, and BCL2), and the histone modifying enzymes (MLL2, RIZ, EZH1, NSD2, KDM5c, JMJD2a, UTX, and JMJD5). Twenty-six (38.8%) patients recurred during the follow-up period (mean duration 47.7 months). In terms of time-to-recurrence (TTR), overexpression of CASP3, TRAIL-R1, and BAX had a longer TTR than low expression, and overexpression of survivin, MDM2, and BCL2 had a shorter TTR than low expression (P<0.05). Additionally, overexpression of MLL2, UTX, and JMJ5 had shorter TTRs than low expression, and overexpression of KDM5c had a longer TTR than low expression. However, in the multi-variate analysis of predicting factors for recurrence, low expression of CASP3 (P<0.001), and BAX (P<0.001), and overexpression of survivin (P=0.007), and MDM2 (P=0.037) were associated with recurrence independently, but any enzymes modifying histone were not associated with recurrence. Conclusively, this study suggests certain apoptosis-associated factors should be associated with recurrence of AMs, which may be regulated epigenetically by histone modifying enzymes.
Duan K, Gomez Hernandez K, Mete OClinicopathological correlates of hyperparathyroidism.
J Clin Pathol. 2015; 68(10):771-87 [PubMed
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Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.
Multiple myeloma (MM) is an incurable clonal plasma cell malignancy. Because of a high rate of immunoglobulin synthesis, the endoplasmic reticulum of MM cells is subjected to elevated basal levels of stress. Consequently, proteasome inhibitors, which exacerbate this stress by inhibiting ubiquitin-proteasome-mediated protein degradation, are an important new class of chemotherapeutic agents being used to combat this disease. However, MM cells still develop resistance to proteasome inhibitors such as carfilzomib. Toward this end, we have established carfilzomib-resistant derivatives of MM cell lines. We found that resistance to carfilzomib was associated with elevated levels of prosurvival autophagy, and Kruppel-like factor 4 (KLF4) was identified as a contributing factor. Expression levels as well as nuclear localization of KLF4 protein were elevated in MM cells with acquired carfilzomib resistance. Chromatin immunoprecipitations indicated that endogenous KLF4 bound to the promoter regions of the SQSTM1 gene encoding the ubiquitin-binding adaptor protein sequestosome/p62 that links the proteasomal and autophagic protein degradation pathways. Ectopic expression of KLF4 induced upregulation of SQSTM1. On the other hand, inhibitors of autophagy sensitized MM cells to carfilzomib, even in carfilzomib-resistant derivatives having increased expression of the multidrug resistance protein P-glycoprotein. Thus, we report here a novel function for KLF4, one of the Yamanaka reprogramming factors, as being a contributor to autophagy gene expression which moderates preclinical proteasome inhibitor efficacy in MM.
Cheng TY, Makar KW, Neuhouser ML, et al.Folate-mediated one-carbon metabolism genes and interactions with nutritional factors on colorectal cancer risk: Women's Health Initiative Observational Study.
Cancer. 2015; 121(20):3684-91 [PubMed
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BACKGROUND: Investigations of folate-mediated one-carbon metabolism (FOCM) genes and gene-nutrient interactions with respect to colorectal cancer (CRC) risk are limited to candidate polymorphisms and dietary folate. This study comprehensively investigated associations between genetic variants in FOCM and CRC risk and whether the FOCM nutrient status modified these associations.
METHODS: Two hundred eighty-eight candidate and tagging single-nucleotide polymorphisms (SNPs) in 30 FOCM genes were genotyped for 821 incident CRC case-control matched pairs in the Women's Health Initiative Observational Study cohort. FOCM biomarkers (red blood cell [RBC] folate, plasma folate, pyridoxal-5'-phosphate [PLP], vitamin B12, and homocysteine) and self-reported alcohol consumption were measured at the baseline. Conditional logistic regression was implemented; effect modification was examined on the basis of known enzyme-nutrient relations.
RESULTS: Statistically significant associations were observed between CRC risk and functionally defined candidate SNPs of methylenetetrahydrofolate dehydrogenase 1 (MTHFD1; K134R), 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR; P450R), and PR domain containing 2 with ZNF domain (PRDM2; S450N) and a literature candidate SNP of thymidylate synthase (TYMS; g.676789A>T; nominal P < .05). In addition, suggestive associations were noted for tagging SNPs in cystathionine-β-synthase (CBS), dihydrofolate reductase (DHFR), DNA (cytosine-5-)-methyltransferase 3β (DNMT3B), methionine adenosyltransferase I α (MAT1A), MTHFD1, and MTRR (nominal P < .05; adjusted P, not significant). Significant interactions between nutrient biomarkers and candidate polymorphisms were observed for 1) plasma/RBC folate and folate hydrolase 1 (FOLH1), paraoxonase 1 (PON1), transcobalamin II (TCN2), DNMT1, and DNMT3B; 2) plasma PLP and TYMS TS3; 3) plasma B12 and betaine-homocysteine S-methyltransferase 2 (BHMT2); and 4) homocysteine and methylenetetrahydrofolate reductase (MTHFR) and alanyl-transfer RNA synthetase (AARS).
CONCLUSIONS: Genetic variants in FOCM genes are associated with CRC risk among postmenopausal women. FOCM nutrients continue to emerge as effect modifiers of genetic influences on CRC risk.
Ge P, Yu X, Wang ZC, Lin JAberrant Methylation of the 1p36 Tumor Suppressor Gene RIZ1 in Renal Cell Carcinoma.
Asian Pac J Cancer Prev. 2015; 16(9):4071-5 [PubMed
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BACKGROUND: Retinoblastoma protein-interacting zinc finger gene 1(RIZ1) functions as a tumor suppressor. Hypermethylation-mediated RIZ1 silencing has been reported in several cancers, but not in renal cell carcinoma (RCC) yet.
MATERIALS AND METHODS: We examined the RIZ1 expression and methylation in a panel of RCC cell lines and 50 primary tumors using semiquantitative/quantitative polymerase chain reaction (PCR), methylation specific PCR, and bisulfite sequencing genomic. We also explored the relationship between methylation status of RIZ1 and clinicopathological features in RCC patients.
RESULTS: RIZ1 expression was down-regulated or lost in OS-RC-2, 769-P, Caki-1, 786-O and A498 RCC cell lines. Restored expression of RIZ1 was detected after addition of 5-aza-2'-deoxycytidine with/without trichostatin A, suggesting that DNA methylation directly mediates its silencing. The RIZ1 expression was significantly reduced in RCCs compared to adjacent non-malignant renal samples (P<0.001). Aberrant methylation was detected in 15 of 50 (30%) RCCs and in 2 of 28 (7%) adjacent non- malignant renal samples (P=0.02). No statistically significant correlation between methylated and unmethylated cases with regard to age, gender, pathological stage and grade was observed.
CONCLUSIONS: RIZ1 expression is down-regulated in human RCC, and this down-regulation is associated with methylation. RIZ1 methylation may play a role in renal carcinogenesis.
Ding MH, Wang Z, Jiang L, et al.The transducible TAT-RIZ1-PR protein exerts histone methyltransferase activity and tumor-suppressive functions in human malignant meningiomas.
Biomaterials. 2015; 56:165-78 [PubMed
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Malignant meningiomas are a rare meningioma subtype and tend to have post-surgical recurrence. Significant endeavors have been taken to identify functional therapeutic targets to halt the growth of this aggressive cancer. We have recently discovered that RIZ1 is downregulated in high-grade meningiomas, and RIZ1 overexpression inhibits proliferation while promoting cell apoptosis of the IOMM-Lee malignant meningioma cell line. In this report, we show that the N-terminal PR domain of RIZ1 alone possessed growth-inhibitory activity and anticancer activity in primary human meningioma cells. Interestingly, the effects seem to be dependent on differential RIZ1 protein levels. Transducible TAT-RIZ1-PR protein could also inhibit meningioma tumor growth in nude mice models. We further demonstrate that PR protein exerts histone methyltransferase activity. A microarray analysis of TAT-RIZ1-PR-treated human malignant meningioma cells reveals 969 differentially expressed genes and 848 alternative splicing exons. Moreover, c-Myc and TXNIP, two putative downstream targets of H3K9 methylation, may be involved in regulating RIZ1 tumor-suppressive effects. The reciprocal relationship between RIZ1 and c-Myc was then validated in primary meningioma cells and human tumor samples. These findings provide insights into RIZ1 tumor suppression mechanisms and suggest that TAT-RIZ1-PR protein is a potential new epigenetic therapeutic agent for advanced meningiomas.
BACKGROUND: Dopamine agonists (DAs) are the first-line treatment for prolactinomas, which account for 25-30% of functioning pituitary adenomas, and bromocriptine (BRC) is the only commercially available DAs in China. However, tumors are resistant to therapy in 5-18% of patients.
METHODS: The exomes of six responsive prolactinomas and six resistant prolactinomas were analyzed by whole-exome sequencing.
RESULTS: Using stringent variant calling and filtering parameters, ten somatic variants that were mainly associated with DNA repair or protein metabolic processes were identified. New resistant variants were identified in multiple genes including PRDM2, PRG4, MUC4, DSPP, DPCR1, RP1L1, MX2, POTEF, C1orf170, and KRTAP10-3. The expression of these genes was then quantified by real-time reverse-transcription PCR (RT-qPCR) in 12 prolactinomas and 3 normal pituitary glands. The mRNA levels of PRDM2 were approximately five-fold lower in resistant prolactinomas than in responsive tumors (p < 0.05). PRDM2 protein levels were lower in resistant prolactinomas than in responsive tumors, as determined by Western blotting and immunohistochemical analysis (p < 0.05). Overexpression of PRDM2 upregulated dopamine receptor D2 (D2DR) and inhibited the phosphorylation of ERK1/2 in MMQ cells. PRDM2 showed a synergistic effect with BRC on the inhibition of prolactin (PRL) secretion and MMQ cell viability, and low PRDM2 expression was associated with tumor recurrence.
CONCLUSIONS: PRDM2 downregulation may play a role in dopamine-agonist resistance and tumor recurrence in prolactinomas.
Brown fat generates heat to protect against cold and obesity. Adrenergic stimulation activates the thermogenic program of brown adipocytes. Although the bioactivity of brown adipose tissue in adult humans had been assumed to very low, several studies using positron emission tomography-computed tomography (PET-CT) have detected bioactive brown adipose tissue in adult humans under cold exposure. In this study, we collected adipose tissues obtained from the perirenal regions of adult patients with pheochromocytoma (PHEO) or non-functioning adrenal tumors (NF). We demonstrated that perirenal brown adipocytes were activated in adult patients with PHEO. These cells had the molecular characteristics of classical brown fat rather than those of beige/brite fat. Expression of brown adipose tissue markers such as uncoupling protein 1 (UCP1) and cell death-inducing DFFA-like effector A (CIDEA) was highly correlated with the amounts of PRD1-BF-1-RIZ1 homologous domain-containing protein-16 (PRDM16) - euchromatic histone-lysine N-methyltransferase 1 (EHMT1) complex, the key transcriptional switch for brown fat development. These results provide novel insights into the reconstruction of human brown adipocytes and their therapeutic application against obesity and its complications such as type 2 diabetes.
Verdelli C, Forno I, Vaira V, Corbetta SEpigenetic alterations in human parathyroid tumors.
Endocrine. 2015; 49(2):324-32 [PubMed
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Epigenetics alterations are involved in tumorigenesis and have been identified in endocrine neoplasia. In particular, DNA methylation, microRNAs deregulations and histone methylation impairment are detected in tumors of the parathyroid glands. Parathyroid tumors are the second most common endocrine neoplasia following thyroid cancer in women, and it is associated with primary hyperparathyroidism, a disease sustained by PTH hypersecretion. Despite the hallmark of global promoter hypomethylations was not detectable in parathyroid tumors, increase of hypermethylation in specific CpG islands was detected in the progression from benign to malignant parathyroid tumors. Furthermore, deregulation of a panel of embryonic-related microRNAs (miRNAs) was documented in parathyroid tumors compared with normal glands. Impaired expression of the histone methyltransferases EZH2, BMI1, and RIZ1 have been described in parathyroid tumors. Moreover, histone methyltransferases have been shown to be modulated by the oncosuppressors HIC1, MEN1, and HRPT2/CDC73 gene products that characterize tumorigenesis of parathyroid adenomas and carcinomas, respectively. The epigenetic scenario in parathyroid tumors have just began to be decoded but emerging data highlight the involvement of an embryonic gene signature in parathyroid tumor development.
miR-17-92 is an oncogenic miRNA cluster implicated in the development of several cancers; however, it remains unknown whether the miR-17-92 cluster is able to regulate cholangiocarcinogenesis. This study was designed to investigate the biological functions and molecular mechanisms of the miR-17-92 cluster in cholangiocarcinoma. In situ hybridization and quantitative RT-PCR analysis showed that the miR-17-92 cluster is highly expressed in human cholangiocarcinoma cells compared with the nonneoplastic biliary epithelial cells. Forced overexpression of the miR-17-92 cluster or its members, miR-92a and miR-19a, in cultured human cholangiocarcinoma cells enhanced tumor cell proliferation, colony formation, and invasiveness, in vitro. Overexpression of the miR-17-92 cluster or miR-92a also enhanced cholangiocarcinoma growth in vivo in hairless outbred mice with severe combined immunodeficiency (SHO-Prkdc(scid)Hr(hr)). The tumor-suppressor, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), was identified as a bona fide target of both miR-92a and miR-19a in cholangiocarcinoma cells via sequence prediction, 3' untranslated region luciferase activity assay, and Western blot analysis. Accordingly, overexpression of the PTEN open reading frame protein (devoid of 3' untranslated region) prevented miR-92a- or miR-19a-induced cholangiocarcinoma cell growth. Microarray analysis revealed additional targets of the miR-17-92 cluster in human cholangiocarcinoma cells, including APAF-1 and PRDM2. Moreover, we observed that the expression of the miR-17-92 cluster is regulated by IL-6/Stat3, a key oncogenic signaling pathway pivotal in cholangiocarcinogenesis. Taken together, our findings disclose a novel IL-6/Stat3-miR-17-92 cluster-PTEN signaling axis that is crucial for cholangiocarcinogenesis and tumor progression.