Oral Cancer


Literature Analysis

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Tag cloud generated 08 August, 2015 using data from PubMed, MeSH and CancerIndex

Mutated Genes and Abnormal Protein Expression (39)

How to use this data tableClicking on the Gene or Topic will take you to a separate more detailed page. Sort this list by clicking on a column heading e.g. 'Gene' or 'Topic'.

NODAL 10q22.1 HTX5 -NODAL and Oral Cavity Cancer
GSTM1 1p13.3 MU, H-B, GST1, GTH4, GTM1, MU-1, GSTM1-1, GSTM1a-1a, GSTM1b-1b -GSTM1 and Oral Cavity Cancer
MMP2 16q12.2 CLG4, MONA, CLG4A, MMP-2, TBE-1, MMP-II -MMP2 and Oral Cancer
GSTT1 22q11.23 -GSTT1 and Oral Cavity Cancer
BAX 19q13.3-q13.4 BCL2L4 -BAX and Oral Cavity Cancer
CA9 9p13.3 MN, CAIX -CA9 and Oral Cavity Cancer
NAT2 8p22 AAC2, PNAT, NAT-2 -NAT2 and Oral Cancer
BCL2 18q21.3 Bcl-2, PPP1R50 -BCL2 and Oral Cavity Cancer
FGF4 11q13.3 HST, KFGF, HST-1, HSTF1, K-FGF, HBGF-4 -FGF4 and Oral Cavity Cancer
GSTM3 1p13.3 GST5, GSTB, GTM3, GSTM3-3 -GSTM3 and Oral Cavity Cancer
MARCO 2q14.2 SCARA2 -MARCO and Oral Cavity Cancer
CTTN 11q13 EMS1 -CTTN and Oral Cavity Cancer
ALDH2 12q24.2 ALDM, ALDHI, ALDH-E2 -ALDH2 and Oral Cavity Cancer
TWIST1 7p21.2 CRS, CSO, SCS, ACS3, CRS1, BPES2, BPES3, TWIST, bHLHa38 -TWIST1 and Oral Squamous Cell Carcinoma
PDPN 1p36.21 T1A, GP36, GP40, Gp38, OTS8, T1A2, TI1A, T1A-2, AGGRUS, HT1A-1, PA2.26 -PDPN and Oral Cavity Cancer
ADH1C 4q23 ADH3 -ADH1C and Oral Cavity Cancer
ABCG2 4q22 MRX, MXR, ABCP, BCRP, BMDP, MXR1, ABC15, BCRP1, CD338, GOUT1, CDw338, UAQTL1, EST157481 -ABCG2 and Oral Cavity Cancer
EDNRB 13q22 ETB, ET-B, ETBR, ETRB, HSCR, WS4A, ABCDS, ET-BR, HSCR2 -EDNRB and Oral Cavity Cancer
CDK2AP1 12q24.31 DOC1, ST19, DORC1, doc-1, p12DOC-1 -CDK2AP1 and Oral Cavity Cancer
AIDA 1q41 C1orf80 -AIDA and Oral Cavity Cancer
LAMC2 1q25-q31 B2T, CSF, EBR2, BM600, EBR2A, LAMB2T, LAMNB2 -LAMC2 and Oral Cavity Cancer
KIAA1524 3q13.13 p90, CIP2A -KIAA1524 and Oral Cavity Cancer
FAT1 4q35 FAT, ME5, CDHF7, CDHR8, hFat1 -FAT1 and Oral Cavity Cancer
MMP10 11q22.3 SL-2, STMY2 -MMP10 and Oral Cavity Cancer
RPS6 9p21 S6 -RPS6 and Oral Cavity Cancer
IMP3 15q24 BRMS2, MRPS4, C15orf12 -IMP3 and Oral Cavity Cancer
ENDOU 12q13.1 P11, PP11, PRSS26 -ENDOU and Oral Cavity Cancer
CSMD1 8p23.2 PPP1R24 -CSMD1 and Oral Cavity Cancer
MALL 2q13 BENE -MALL and Oral Cavity Cancer
FGF19 11q13.1 -FGF19 and Oral Cavity Cancer
THBS2 6q27 TSP2 -THBS2 and Oral Cavity Cancer
NTRK2 9q22.1 TRKB, trk-B, GP145-TrkB -NTRK2 and Oral Cavity Cancer
HOXC13 12q13.3 HOX3, ECTD9, HOX3G -HOXC13 and Oral Cavity Cancer
ING5 2q37.3 p28ING5 -ING5 and Oral Cavity Cancer
BCL2A1 15q24.3 GRS, ACC1, ACC2, BFL1, ACC-1, ACC-2, HBPA1, BCL2L5 -BCL2A1 and Oral Cavity Cancer
CFLAR 2q33-q34 CASH, FLIP, MRIT, CLARP, FLAME, Casper, FLAME1, c-FLIP, FLAME-1, I-FLICE, c-FLIPL, c-FLIPR, c-FLIPS, CASP8AP1 -CFLAR and Oral Cavity Cancer
RXRB 6p21.3 NR2B2, DAUDI6, RCoR-1, H-2RIIBP -RXRB and Oral Cavity Cancer
GHRH 20q11.2 GRF, INN, GHRF -GHRH and Oral Cavity Cancer
BDNF 11p13 ANON2, BULN2 -BDNF and Oral Cavity Cancer

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications

Fan S, Chen WX, Lv XB, et al.
miR-483-5p determines mitochondrial fission and cisplatin sensitivity in tongue squamous cell carcinoma by targeting FIS1.
Cancer Lett. 2015; 362(2):183-91 [PubMed] Related Publications
Mitochondria play an important role in the initiation of apoptosis. However, whether cisplatin can induce apoptosis by initiating a mitochondrial fission pathway and the mechanism underlying this effect remain poorly understood. In this study, we show that the mitochondrial fission protein FIS1 is upregulated upon cisplatin treatment in tongue squamous cell carcinoma (TSCC) cells. FIS1 knockdown can attenuate mitochondrial fission and cisplatin sensitivity. We found that FIS1 is a direct target of miR-483-5p and that miR-483-5p can inhibit mitochondrial fission and cisplatin sensitivity in vitro and in vivo. Furthermore, we found that miR-483-5p and FIS1 are significantly associated with cisplatin sensitivity and with overall survival in patients with TSCC in a retrospective analysis of multiple centers. This study revealed that a novel mitochondrial fission pathway composed of miR-483-5p and FIS1 regulates cisplatin sensitivity. The modulation of miR-483-5p and FIS1 levels may provide a new approach for increasing cisplatin sensitivity.

Yu C, Guo J, Liu Y, et al.
Oral squamous cancer cell exploits hnRNP A1 to regulate cell cycle and proliferation.
J Cell Physiol. 2015; 230(9):2252-61 [PubMed] Related Publications
Oral squamous cell carcinoma (OSCC) is a common human malignant tumor with high mortality. So far, the molecular pathogenesis of OSCC remains largely unclear. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is an important multi-function splicing factor and closely related to tumorigenesis. hnRNP A1 is overexpressed in various tumors, and promotes aerobic glycolysis and elongation of telomere, but the function of hnRNP A1 in cell cycle and proliferation remains unclear. We found that hnRNP A1 was overexpressed in OSCC tissues, and was required for the growth of OSCC cells. Moreover, hnRNP A1 was highly expressed in the G2/M cell cycle phase. Knockdown of hnRNP A1 induced G2/M arrest. DNA microarray assay result showed that hnRNP A1 regulated the expression of a number of target genes associated with G2/M phase. Moreover, hnRNP A1 controlled the alternative splicing of CDK2 exon 5. These findings suggested that hnRNP A1 plays key roles in the regulation of cell cycle progression and pathogenesis of OSCC.

Arantes LM, de Carvalho AC, Melendez ME, et al.
Validation of methylation markers for diagnosis of oral cavity cancer.
Eur J Cancer. 2015; 51(5):632-41 [PubMed] Related Publications
PURPOSE: Activation of proto-oncogenes and inactivation of tumour suppressor genes are the major genetic alterations involved in carcinogenesis. The increase in methylation at the promoter region of a tumour suppressor gene can lead to gene inactivation, selecting cells with proliferative advantage. Thus, promoter hypermethylation is considered a marker in a variety of malignant tumours, including oral cavity.
EXPERIMENTAL DESIGN: The methylation pattern of eight genes was evaluated in 40 oral cavity squamous cell carcinomas (OSCCs) and 40 saliva samples from healthy individuals by Q-MSP. Different combinations of genes were also assessed in order to identify gene panels that could better distinguish between OSCC and saliva samples.
RESULTS: CCNA1, DAPK, DCC and TIMP3 methylation were highly specific for being found in the OSCC samples. Moreover, the combination of these genes improved detection when compared with single markers, reaching values of 92.5% for sensitivity and specificity (when using the panel CCNA1, DCC, TIMP3). Moreover, DAPK, DCC and TIMP3 were hypermethylated in nearly 90% of clinically T1 and T2 cases.
CONCLUSION: The pursuing of this panel of hypermethylated genes is an important tool for the detection of individuals with OSCC. Moreover, the identification of these markers in early stages of OSCC shows the feasibility of using the panel on saliva as possible biomarkers for early diagnosis. The lack of association between the methylation status of these genes and clinical characteristics shows that they are able to distinguish OSCC cases irrespective of social and clinical factors (gender, age, human papillomavirus (HPV) status, clinical stage, vascular embolisation and perineural invasion).

Chang CC, Chang YS, Chan WL, et al.
Detection of SF3B3 gene mutations in oral cancer by high resolution melting analysis.
Clin Lab. 2014; 60(12):2023-9 [PubMed] Related Publications
BACKGROUND: There is a high prevalence of oral cancer in Taiwan, which is associated with betel quid chewing. Gene encoding splicing factors, especially splicing factor 3b subunit 1 (SF3B1), have been shown to be the most highly mutated in various hematological malignancies and have a great influence on clinical outcomes. However, few splicing targets have been identified for oral cancer. The aim of this study was to explore splicing factor 3b subunit 3 (SF3B3) gene mutations in oral cancer.
METHODS: High resolution melting (HRM) analysis was used to characterize SF3B3 polymorphisms. Genomic DNA was extracted from 78 oral cancer tissues, and every exon from exon 2 to exon 26 of the SF3B3 gene was screened by HRM analysis. All results were confirmed by direct DNA sequencing over the range of codons of interest.
RESULTS: Only one single nucleotide polymorphism with amino acid substitution was found to change from serine to asparagine at codon 811 (S811N) in exon 18 with an allele frequency of 1.3%.
CONCLUSIONS: The molecular effects of drugs targeting the splicing factors in various cancers may offer a new perspective for the role in cancer progression and the development of novel antitumor therapy. HRM analysis with direct sequencing over the range of codons of interest is a fast, reliable, accurate, and cost-effective screening method to detect unknown gene mutations.

Ito Y, Ishibashi K, Masaki A, et al.
Mammary analogue secretory carcinoma of salivary glands: a clinicopathologic and molecular study including 2 cases harboring ETV6-X fusion.
Am J Surg Pathol. 2015; 39(5):602-10 [PubMed] Related Publications
Mammary analogue secretory carcinoma (MASC) is a recently described low-grade carcinoma with morphologic and genetic similarity, including ETV6-NTRK3 fusion, to secretory carcinoma of the breast. ETV6 is frequently involved in other epithelial and nonepithelial tumors, and many fusion partners of ETV6 have been reported. In the present study, 14 Japanese MASC cases were clinicopathologically and molecularly analyzed. The median age of the patients was 39 years, and the male:female ratio was 6:8. All cases showed histopathologic findings compatible with those previously described for MASC and harbored an ETV6 split as visualized by fluorescence in situ hybridization. Two cases showed thick fibrous septa and invasive features including vascular or perineural tumor involvement, findings that are rare in MASC. In addition, in these 2 cases, non-NTRK3 genes appeared to fuse with ETV6 (ETV6-X fusion). NTRK1 and NTRK2, both members of the NTRK family, were not involved. Of the 14 MASC cases, the ETV6-NTRK3 fusion transcript was positive in 6 cases, and the relative expression level of the ETV6-NTRK3 fusion transcript was variable, ranging from 1 to 5.8. Results of the present study of MASC suggest that (1) ETV6 occasionally fuses with unknown non-NTRK3 genes, (2) ETV6-X cases might have an invasive histology, (3) for molecular diagnosis of MASC, fluorescence in situ hybridization to detect ETV6 splits is the method of choice, and (4) the expression level of the ETV6-NTRK3 fusion transcript is considerably variable. These findings provide a novel insight into the oncogenesis, histopathology, diagnosis, treatment, and prognosis of this newly recognized carcinoma.

Ma L, Chen J, Song X, et al.
Evidence that the genetic polymorphism rs1412115 on chromosome 10 is associated with risk for oral squamous cell carcinoma.
Gene. 2015; 560(2):137-9 [PubMed] Related Publications
A genome-wide association study on schizophrenia in Jewish population discovered a novel single nucleotide polymorphism (SNP), rs1412115, on chromosome 10. It has been proved that neuropilin-1 (NRP-1) gene located on chromosome 10, tightly close to rs1412115, is associated with increased risk for oral squamous cell carcinoma (OSCC). In the present study, we hypothesized that SNP rs1412115:A>G is associated with increased risk for OSCC. We therefore genotyped this polymorphism in 295 patients with OSCC and 594 cancer-free controls in the Chinese Han population, using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy. The pooled odds ratio was 1.42 (95% confidence interval [CI]=1.01-1.99, p=0.042) for carriers with the A version of the allele (AA and AG) compared with GG, and 1.46 (95% CI=1.02-2.09, p=0.036) for AG compared with GG. Our data provide evidence that the rs1412115: A>G polymorphism increases the risk of OSCC in Chinese Han populations. Larger population-based studies are needed to confirm these results.

Su S, Chien M, Lin C, et al.
RAGE gene polymorphism and environmental factor in the risk of oral cancer.
J Dent Res. 2015; 94(3):403-11 [PubMed] Related Publications
Oral squamous cell carcinoma is a common neoplasm that is known to be causally associated with genetic factors and environmental carcinogens. The receptor for advanced glycosylation endproducts (RAGE) is a transmembrane protein of the immunoglobulin superfamily with broad specificity for multiple ligands, and it has been shown to play vital roles in several pathophysiologic processes, including diabetes, Alzheimer disease, renal disease, cardiovascular disease, and cancer. The present study aimed to assess the influences of RAGE gene polymorphisms, combined with environmental carcinogens on the predisposition to oral tumorigenesis. Five polymorphisms of the RAGE gene-including -374T>A (rs1800624), -429T>C (rs1800625), 1704G>T (rs184003), Gly82Ser (rs2070600), and a 63-bp deletion allele (-407 to -345)-were examined from 592 controls and 618 patients with oral cancer. We found that individuals carrying the polymorphic allele of rs1800625 are more susceptible to oral cancer (odds ratio [OR], 1.899; 95% confidence interval [CI], 1.355 to 2.661; adjusted OR [AOR], 2.053; 95% CI, 1.269 to 3.345) after adjustment for age, sex, betel nut chewing, and tobacco consumption. Moreover, we observed a significant association of rs1800625 variants with late-stage tumors (stage III/IV, OR, 1.736; 95% CI, 1.126 to 2.677; AOR, 1.771; 95% CI, 1.101 to 2.851) and large-size tumors (>2 cm in the greatest dimension; OR, 1.644; 95% CI, 1.083 to 2.493; AOR, 1.728; 95% CI, 1.089 to 2.741). Based on behavioral exposure of environmental carcinogens, the presence of 4 RAGE single-nucleotide polymorphisms (SNPs), combined with betel quid chewing and/or tobacco use, greatly augmented the risk of oral cancer. In addition, carriers of particular haplotypes of the 4 RAGE SNPs examined are more prone to develop oral cancer. These results indicate an involvement of RAGE SNP rs1800625 in the development of oral squamous cell carcinoma and implicate the interaction between RAGE gene polymorphisms and environmental mutagens as a predisposing factor of oral carcinogenesis.

Skálová A, Weinreb I, Hyrcza M, et al.
Clear cell myoepithelial carcinoma of salivary glands showing EWSR1 rearrangement: molecular analysis of 94 salivary gland carcinomas with prominent clear cell component.
Am J Surg Pathol. 2015; 39(3):338-48 [PubMed] Related Publications
This study examines the presence of the EWSR1 rearrangement in a variety of clear cell salivary gland carcinomas with myoepithelial differentiation. A total of 94 salivary gland carcinomas with a prominent clear cell component included 51 cases of clear cell myoepithelial carcinomas de novo (CCMC), 21 cases of CCMCs ex pleomorphic adenoma (CCMCexPA), 11 cases of epithelial-myoepithelial carcinoma (EMC), 6 cases of EMC with solid clear cell overgrowth, and 5 cases of hyalinizing clear cell carcinoma of minor salivary glands. In addition, 10 cases of myoepithelial carcinomas devoid of clear cell change and 12 cases of benign myoepithelioma were included as well. All the tumors in this spectrum were reviewed, reclassified, and tested by fluorescence in situ hybridization (FISH) for the EWSR1 rearrangement using the Probe Vysis EWSR1 Break Apart FISH Probe Kit. The EWSR1 rearrangement was detected in 20 of 51 (39%) cases of CCMC, in 5 of 21 (24%) cases of CCMCexPA, in 1 of 11 (9%) cases of EMC, and in 4 of 5 (80%) cases of hyalinizing clear cell carcinoma. The 25 EWSR1-rearranged CCMCs and CCMCexPAs shared similar histomorphology. They were arranged in nodules composed of compact nests of large polyhedral cells with abundant clear cytoplasm. Necrosis, areas of squamous metaplasia, and hyalinization were frequent features. Immunohistochemically, the tumors expressed p63 (96%), cytokeratin CK14 (96%), and S100 protein (88%). MIB1 index varied from 10% to 100%, with most cases in the 20% to 40% range. Clinical follow-up information was available in 21 cases (84%) and ranged from 3 months to 15 years (mean 5.2 y); 4 patients were lost to follow-up. Ten patients are alive with no evidence of recurrent or metastatic disease in the follow-up period from 3 months to 15 years (mean 5 y), 3 patients are alive with recurrent and metastatic disease, and 8 died of disseminated cancer 9 months to 16 years after diagnosis (mean 6 y). Lymph node metastasis appeared in 5 patients within 5 months to 4 years after diagnosis (mean 22 mo), distant metastases were noted in 7 patients with invasion of orbit (2 cases), and in 1 case each metastasis to the neck soft tissues, liver, lungs, mediastinum, and thoracic vertebra was noted. We describe for the first time EWSR1 gene rearrangement in a subset of myoepithelial carcinomas arising in minor and major salivary glands. The EWSR1-rearranged CCMC represents a distinctive aggressive variant composed predominantly of clear cells with frequent necrosis. Most EWSR1-rearranged CCMCs of salivary glands are characterized by poor clinical outcomes.

Li N, Zhang C, Chen Z, et al.
Interleukin 17A and interleukin 17F polymorphisms are associated with oral squamous cell carcinoma susceptibility in a Chinese population.
J Oral Maxillofac Surg. 2015; 73(2):267-73 [PubMed] Related Publications
PURPOSE: Several studies have investigated the association of the interleukin (IL) 17A and IL-17F polymorphisms and cancer of various organs. However, the role of the IL-17A and IL-17F polymorphisms in oral squamous cell carcinoma (OSCC) remains unclear. Thus we sought to clarify the association of the rs2275913, rs763780, and rs2397084 polymorphisms with OSCC in a Chinese population.
MATERIALS AND METHODS: A TaqMan single-nucleotide polymorphism Genotyping Assay (ABI, Foster, CA) was used to measure the distributions of the IL-17A (rs2275913) and IL-17F (rs763780, rs2397084) polymorphisms in 121 OSCC patients and 103 healthy controls. The association of those polymorphisms and clinical OSCC patient characteristic also was evaluated.
RESULTS: Individuals carrying the rs2275913 A allele and AA genotype had an increased risk of OSCC (odds ratio [OR], 1.463; 95% confidence interval [CI], 0.807 to 2.652; and OR, 2.713; 95% CI, 1.250 to 5.889, respectively). The frequency of the rs2397084 T allele was significantly associated with a higher risk of OSCC than the G allele (OR, 1.501; 95% CI, 1.026 to 2.196). No difference in rs763780 frequencies was observed. The rs2275913 AA and rs2397084 TT genotypes also were associated with late clinical stages and poor tumor differentiation. In addition, stratification analysis indicated that the rs2275913 AA genotype increased OSCC risk among smoking and drinking populations (OR, 4.000; 95% CI, 1.404 to 11.394; and OR, 3.500; 95% CI, 1.018 to 12.030, respectively). In a smoking population, an rs9382084 T-allele carrier has a greater potential risk of OSCC than the overall population (OR, 2.200; 95% CI, 1.009 to 4.797).
CONCLUSIONS: The results of this study suggest a significant association of rs2275913 and rs2397084 but not rs763780 with OSCC risk, and this was related to tumor stage and differentiation. In addition, the IL-17A and IL-17F polymorphisms can interact with smoking and drinking to enhance the risk of OSCC developing.

Maimaiti A, Abudoukeremu K, Tie L, et al.
MicroRNA expression profiling and functional annotation analysis of their targets associated with the malignant transformation of oral leukoplakia.
Gene. 2015; 558(2):271-7 [PubMed] Related Publications
In spite the tremendous achievements that have been acquired in the field of molecular biology, the underlying mechanism associated with malignant transformed oral leukoplakia (OLK) is still unclear and poorly understood. The aim of this study is to investigate the microRNA (miRNA) expression profiles in OLK and its aggressive transformed tissues from the white lesion of human oral mucosa. The original miRNA expression dataset was downloaded from Gene Expression Omnibus (GEO) database and differentially expressed miRNAs were identified using two-sample t test method. Unsupervised hierarchical clustering and principal component analysis of these differentially expressed miRNAs indicated that 38-miRNA candidates could significantly discriminate OLK from malignant transformed oral mucosa samples. Besides, potential transcription factors were predicted using CyTargetLinker plugin and the miRNA-mRNA regulatory network associated with the malignant pathogenesis was visualized in Cytoscape environment. Totally, 3-miRNA signatures (miR-129-5p, miR-339-5p and miR-31*) were found to be hubs that mediated the initiation and progression of OLK from the non-malignant to the aggressive one via targeting various transcription factors. Functional enrichment analysis based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) suggested that the dysregulation of immune response was responsible for oral carcinogenesis. In conclusion, we constructed a miRNA-mRNA regulatory network associated with the malignant transformation of OLK, and screened out some miRNAs and transcription factors that may have prominent roles during OLK malignant progression.

Datta S, Chattopadhyay E, Ray JG, et al.
D-loop somatic mutations and ∼5 kb "common" deletion in mitochondrial DNA: important molecular markers to distinguish oral precancer and cancer.
Tumour Biol. 2015; 36(4):3025-33 [PubMed] Related Publications
Apart from genomic DNA, mutations at mitochondrial DNA (mtDNA) have been hypothesized to play vital roles in cancer development. In this study, ∼5 kb deletion and D-loop mutations in mtDNA and alteration in mtDNA content were investigated in buccal smears from 104 healthy controls and 74 leukoplakia and 117 cancer tissue samples using Taqman-based quantitative assay and re-sequencing. The ∼5 kb deletion in mtDNA was significantly less (9.8 and 10.5 folds, P < 0.0001) in cancer tissues compared to control and leukoplakia tissues, respectively. On the other hand, somatic mutations in D-loop, investigated in 54 controls, 50 leukoplakias and 56 cancer patients, were found to be significantly more in cancer tissues, but not in leukoplakia tissues, compared to control (Z-score = 5.4). MtDNA contents were observed to be significantly more in leukoplakia (2.1 folds, P = 0.004) and cancer (1.6 folds, P = 0.03) tissues compared to control tissues. So, D-loop somatic mutations and ∼5 kb deletion patterns could be used as distinguishing markers between precancer and cancer tissues. This observation further suggests that somatic mutations in D-loop may facilitate carcinogenesis and cancer cells with less ∼5 kb deletion, i.e., intact mtDNA, may become resistant to apoptosis.

Rodrigues MF, de Oliveira Rodini C, de Aquino Xavier FC, et al.
PROX1 gene is differentially expressed in oral cancer and reduces cellular proliferation.
Medicine (Baltimore). 2014; 93(28):e192 [PubMed] Related Publications
Homeobox genes are a family of transcription factors that play a pivotal role in embryogenesis. Prospero homeobox 1 (PROX1) has been shown to function as a tumor suppressor gene or oncogene in various types of cancer, including oral squamous cell carcinoma (OSCC). We have previously identified PROX1 as a downregulated gene in OSCC. The aim of this study is to clarify the underlying mechanism by which PROX1 regulates tumorigenicity of OSCC cells. PROX1 mRNA and protein expression levels were first investigated in 40 samples of OSCC and in nontumor margins. Methylation and amplification analysis was also performed to assess the epigenetic and genetic mechanisms involved in controlling PROX1 expression. OSCC cell line SCC9 was also transfected to stably express the PROX1 gene. Next, SCC9-PROX1-overexpressing cells and controls were subjected to proliferation, differentiation, apoptosis, migration, and invasion assays in vitro. OSCC samples showed reduced PROX1 expression levels compared with nontumor margins. PROX1 amplification was associated with better overall survival. PROX1 overexpression reduces cell proliferation and downregulates cyclin D1. PROX1-overexpressing cells also exhibited reduced CK18 and CK19 expression and transcriptionally altered the expression of WISP3, GATA3, NOTCH1, and E2F1. Our results suggest that PROX1 functions as a tumor suppressor gene in oral carcinogenesis.

Gurtsevitch VE, Iakovleva LS, Shcherbak LN, et al.
[The LMP1 oncogene sequence variations in patients with oral tumours associated or not associated with the Epstein Barr].
Mol Biol (Mosk). 2013 Nov-Dec; 47(6):987-95 [PubMed] Related Publications
The role of the Epstein-Barr virus (EBV), a ubiquitous lymphotropic human herpesvirus type 4, in the etiology of nasopharyngeal carcinoma (NPC) is not fully understood. The mechanism of NPC carcinogenesis, associated with the virus, is also not clear. The objective of present investigation was to carry out comparative analysis of the structure of an LMP1 oncogene of EBV in viral isolates obtained from patients with two types of tumors of the oral cavity: (a) associated (i.e., NPC) and (b) not associated (other tumors of the same anatomical region, OTOC) with EBV. Comparative analysis of C-terminal regions of LMP1 variants that was based on a sequence analysis of LMP1 from tumor, blood and throat washing samples of NPC and OTOC patients showed that all structural characteristics of LMP1 in both groups of patients were genetically similar, and differences found between compared parameters were statistically insignificant. Thus, for the first time it has been revealed that in NPC and OTOC patients in Russia genetically related EBV strains with structurally similar LMP1 variants are persisting that are likely to reflect a polymorphism of the virus circulating in population. The findings allow us to suggest that in non-NPC-endemic regions of the world, which include Russia, the risk of NPC development does not depend on the EBVstrain and its variant of LMP1 so much, but mostly from the genetic predisposition of infected persons to the disease and the exposure to other, as yet unknown agents.

Majewska H, Skálová A, Stodulski D, et al.
Mammary analogue secretory carcinoma of salivary glands: a new entity associated with ETV6 gene rearrangement.
Virchows Arch. 2015; 466(3):245-54 [PubMed] Free Access to Full Article Related Publications
Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumour that harbours the recurrent ETV6-NTRK3 translocation. This is the first series of MASC cases identified in the historic cohort of carcinomas of salivary glands with clinical/pathological correlation and follow-up data. We reviewed 183 primary carcinomas of major and minor salivary glands resected at the Medical University of Gdańsk, Poland, between 1992 and 2012. Based on morphology and immunohistochemistry, cases suspicious for MASC were selected, and the diagnosis was confirmed by fluorescence in situ hybridization (FISH) for ETV6 rearrangement and by RT-PCR for the ETV6-NTRK3 fusion transcript. Seven carcinomas met the criteria of MASC, as they exhibited a typical appearance with solid/microcystic and papillary architecture and intraluminal secretions, and cells completely devoid of basophilic cytoplasmic zymogen granules indicative of true acinar differentiation. The only paediatric case was an unencapsulated tumour composed of macrocystic structures covered by a mostly single but, focally, double layer of cells with apocrine morphology. In all cases, the neoplastic cells revealed immunoreactivity for S100, mammaglobin, cytokeratin CK7, CK8, STAT5a and vimentin. FISH for ETV6 gene rearrangement was positive in six out of seven cases, and RT-PCR was positive in three cases. MASC is a new entity of malignant epithelial salivary gland tumours not included in the 2005 WHO Classification of Head and Neck Tumours. There is a growing body of evidence that it is not as rare as was assumed, as is also indicated by our series (3.8 %). In most cases, MASC shares some microscopic features with AciCC, adenocarcinoma/cystadenocarcinoma NOS and low-grade MEC. In rare cases, MASC with high-grade transformation may mimic the morphological appearances of high-grade salivary gland malignancies, such as salivary duct carcinoma.

Paluszczak J, Sarbak J, Kostrzewska-Poczekaj M, et al.
The negative regulators of Wnt pathway-DACH1, DKK1, and WIF1 are methylated in oral and oropharyngeal cancer and WIF1 methylation predicts shorter survival.
Tumour Biol. 2015; 36(4):2855-61 [PubMed] Free Access to Full Article Related Publications
The deregulation of Wnt signaling has recently emerged as one of the drivers of head and neck cancers. This is frequently related to the methylation of several antagonists of this pathway. This study aimed at the assessment of the profile of methylation of Wnt pathway antagonists and the determination of the prognostic value of the methylation of selected genes in oral carcinomas. The methylation of DACH1, DKK1, LKB1, PPP2R2B, RUNX3, SFRP2, and WIF-1 was analyzed in 16 oral squamous cell carcinoma cell lines using the methylation-specific polymerase chain reaction. The methylation of selected genes was further analyzed in tumor sections from 43 primary oral carcinoma patients. The analysis of oral carcinoma cell lines showed very frequent methylation of SFRP2 and WIF-1 and also a less frequent methylation of DACH1 and DKK1. On the other hand, RUNX3 was methylated only in one cell line, while LKB1 and PPP2R2B were not methylated in any of the cell lines. The biallelic methylation of DKK1 correlated with the low level of expression of this gene. Further evaluation of the methylation of DACH1, DKK1, and WIF1 in a clinical patient group confirmed the frequent methylation of WIF1 and intermediate or low frequency of methylation of DACH1 or DKK1, respectively. Importantly, the methylation of WIF-1 correlated with shorter survival in oral cancer patients. Overall, the methylation of the antagonists of Wnt pathway is frequently detected in oral squamous cell carcinomas. The methylation of WIF1 may be considered a prognostic marker in oral cancers.

Jiang F, Zhao W, Zhou L, et al.
MiR-222 targeted PUMA to improve sensitization of UM1 cells to cisplatin.
Int J Mol Sci. 2014; 15(12):22128-41 [PubMed] Free Access to Full Article Related Publications
microRNAs have been shown to play critical roles in regulating the chemosensitivity of cancer cells. As a member of the oncogenic miRNAs (oncomiRs), miR-222 has been reported to drive the oncogenesis of many types of malignancies. However, little is known concerning the specific role of miR-222 in human oral squamous cell carcinoma (OSCC). The present study explored the role and mechanism of miR-222 in increasing the expression of p53 up-regulated modulator of apoptosis (PUMA) and enhancing the sensitivity of OSCC to cisplatin (CDDP). Results showed that antisense (As)-miR-222 inhibits the expression of miR-222. In contrast, PUMA was dramaticallyup-regulated. IC50 values were significantly decreased in cells treated with As-miR-222 combined with CDDP, to a greater extent than in cells treated with CDDP alone. Furthermore, As-miR-222 enhanced apoptosis and inhibited the invasiveness of UM1 cells. Analysis of the above data suggested that, in UM1 cells, there might be a regulatory loop between miR-222 and PUMA, and that miR-222 inhibition increased the chemosensitivity to CDDP. These findings demonstrated that down-regulation of miR-222 could enhance the chemosensitivity of human OSCC cells to CDDP, and that the combination of As-miR-222 and CDDP could be an effective therapeutic strategy by boosting the expression of PUMA for controlling the growth of OSCC.

Zhang D, Ni Z, Xu X, Xiao J
MiR-32 functions as a tumor suppressor and directly targets EZH2 in human oral squamous cell carcinoma.
Med Sci Monit. 2014; 20:2527-35 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: MicroRNA-32 (miR-32) is dysregulated in certain human malignancies and correlates with tumor progression. However, its expression and function in oral squamous cell carcinoma (OSCC) remain unclear. Thus, the aim of this study was to explore the effects of miR-32 expression on OSCC tumorigenesis and development.
MATERIAL/METHODS: Real-time quantitative PCR was applied to evaluate the expression level of miR-32 in OSCC cell lines and primary tumor tissues. The association of miR-32 expression with clinicopathological factors and prognosis was also analyzed. In vitro cell proliferation, apoptosis, invasion, and migration assays were executed to elucidate biological effects of miR-32. Western blotting and luciferase assays were performed to confirm the regulation of EZH2 by miR-32.
RESULTS: Down-regulation of miR-32 was found in OSCC tissues compared with corresponding noncancerous tissues (P<0.001). Decreased miR-32 expression was significantly associated with advanced T classifications, positive N classification, advanced TNM stage, and shorter overall survival (all P<0.05). Multivariate regression analysis corroborated that low-level expression of miR-32 was an independent unfavorable prognostic factor for OSCC patients. In vitro functional assays showed that overexpression of miR-32 reduced OSCC cell proliferation, migration, and invasion, and promoted cell apoptosis. In contrast, miR-32 knock-down resulted in an increase in cell growth and invasiveness. Finally, we identified EZH2 as the functional downstream target of miR-32 by directly targeting the 3'-UTR of EZH2.
CONCLUSIONS: These findings indicate that miR-32 may act as a tumor suppressor in OSCC and could serve as a novel therapeutic agent for miR-based therapy.

Andisheh-Tadbir A, Ashraf MJ, Khademi B, Ahmadi S
Clinical implication of CD166 expression in salivary gland tumor.
Tumour Biol. 2015; 36(4):2793-9 [PubMed] Related Publications
CD166 is a glycoprotein of immunoglobulin superfamily of adhesion molecules which is overexpressed in many tumors. However, no published literature was found concerning CD166 expression in salivary gland tumor. The purpose of this study was to examine the CD166 expression in the salivary gland tumor by an immunohistochemical approach, to examine the clinical implication of this marker in the prognosis and diagnosis of the salivary gland tumor. In this study, 45 samples of salivary tumors from Khalili Hospital archive including 15 cases of pleomorphic adenoma, 16 cases of mucoepidermoid carcinoma, 14 cases of adenoid cystic carcinoma, and 15 normal salivary glands were selected for immunohistochemistry (IHC) method staining for CD166. CD166 immunoreactivity in malignant tumors (adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC)) (56.7 ± 14.05) was significantly higher than that of pleomorphic adenoma (PA) (34.3 ± 17.07) (P < 0.000) and higher in the PA than normal salivary gland (13.2 ± 12.1) (P = 0.001). CD166 expression was significantly higher in the high-grade tumors (90.3 ± 11.07) compared to low-grade (65.11 ± 27.08) malignant tumors (P = 0.002). CD166 expression showed a significant association with tumor size and the clinical stage (P < 0.001). In conclusion, an overexpression of CD166 was detected in the benign and malignant salivary gland tumors and its expression in the malignant tumor was associated with the aggressive behavior and tumor progression. For this reason, CD166 may be one of the potential biomarkers for predicting tumor behavior in the prognosis of this disease.

Urano M, Nagao T, Miyabe S, et al.
Characterization of mammary analogue secretory carcinoma of the salivary gland: discrimination from its mimics by the presence of the ETV6-NTRK3 translocation and novel surrogate markers.
Hum Pathol. 2015; 46(1):94-103 [PubMed] Related Publications
Mammary analogue secretory carcinoma (MASC) is a recently recognized salivary gland tumor harboring an ETV6-NTRK3 translocation similar to secretory carcinoma of the breast. Histologically, MASC mimics papillary-cystic, microcystic, and follicular-type acinic cell carcinoma (AciCC) and low-grade cribriform cystadenocarcinoma (LGCCC) of the salivary gland. Using histology, immunohistochemistry (IHC), and molecular genetic techniques, we reevaluated 18 cases originally diagnosed as AciCC between 1993 and 2012. The last of these methods was used to detect the ETV6-NTRK3 translocation. The results reconfirmed 6 cases as AciCC (3 men; average age, 63 years) and helped us reclassify 10 cases as MASC (6 men; mean age, 46 years) and 2 as LGCCC (2 women; mean age, 48 years). Using IHC, we identified the 3 histologic types according to the expression patterns of vimentin, high-molecular-weight cytokeratin, cytokeratin 19, S-100, mammaglobin, MUC1, GATA-binding protein 3, adipophilin, α-amylase, DOG-1, SOX-10, and p63. The number of tumors diagnosed as MASC indicates that AciCC includes bona fide MASC cases. Because differential diagnosis among zymogen granule-poor AciCC, MASC, and LGCCC tumors is challenging, we recommend using molecular genetic tests for ETV6-NTRK3 for accurate diagnosis. Furthermore, detailed analyses of hematoxylin and eosin-stained tissues and IHC studies using the markers described here should be incorporated into routine practices.

Zhang XY,
Expression of growth arrest and DNA damage inducible 45a in human oral squamous cell carcinoma is associated with tumor progression and clinical outcome.
J Cancer Res Ther. 2014; 10 Suppl:C108-13 [PubMed] Related Publications
OBJECTIVES: The aim of this study was to examine the growth arrest and DNA damage-inducible (Gadd45a) expression and its role in tumor progression, invasion and metastasis in oral squamous cell carcinoma (OSCC).
MATERIALS AND METHODS: Growth arrest and DNA damage-inducible 45a distribution was detected by immunohistochemistry in tumor sections of 106 patients with primary OSCC and sections of adjacent pericancerous tissues from 60 patients among the 106. The association between the Gadd45a expression and clinical prognosis of OSCC were performed by statistical analysis. Gadd45a gene knockdown was performed in Tca8113 cells by small interfering ribonucleic acid treatment and its effects on cell cycle, and migration were detected by Flow Cytometric (Becton Dickinson, USA) and transwell chamber assay respectively.
RESULTS AND CONCLUSION: The results showed that Gadd45a was redistributed to cytoplasm in poorly differentiated carcinoma from its nucleus location in normal tissue (P < 0.05). The expression of Gadd45a was significantly associated with lymph node metastasis, tumor stage and tumor histological grade (P < 0.05). Knockdown of Gadd45a gene abolished the G2/M arrest and increased migrating ability of Tca8113 cell (P < 0.05). The results indicate that Gadd45a play an important role in OSCC metastasis by affecting the bioactivity of the tumor cells, and its distribution may serve for the prediction of clinical outcome of OSCC.

Goyal B, Duncavage EJ, Martinez D, et al.
Next-generation sequencing of salivary high-grade neuroendocrine carcinomas identifies alterations in RB1 and the mTOR pathway.
Exp Mol Pathol. 2014; 97(3):572-8 [PubMed] Related Publications
Salivary gland high-grade neuroendocrine carcinomas are rare, aggressive tumors that are morphologically and immunohistochemically similar to cutaneous high-grade neuroendocrine (Merkel cell) carcinomas. The majority of Merkel cell carcinomas harbor Merkel cell polyomavirus, while the virus is rare or absent in salivary high-grade neuroendocrine carcinomas. Inactivation of retinoblastoma 1 (RB1) has been implicated in the pathogenesis of both virus-positive and -negative Merkel cell carcinomas but by different mechanisms. In virus-positive tumors, a portion of the viral genome, the large T antigen, may inactivate RB1, and in virus-negative Merkel cell carcinomas truncating mutations in the RB1 gene have been identified. The molecular genetics of salivary high-grade neuroendocrine carcinomas are not well understood. Here, we performed targeted next-generation sequencing of 151 cancer-related genes on 4 four Merkel cell polyomavirus-negative primary salivary gland high-grade neuroendocrine carcinoma cases. Somatic mutations were predominantly found within tumor suppressor genes [TP53 (3 cases), PTEN (2 cases), RB1 (1 case)]. Truncating RB1 mutations, as seen in virus-negative Merkel cell carcinomas, were not identified. However, 3 of 4 cases had RB1 deletions by copy number variation analysis. The 4th case had loss of heterozygosity for RB1. Fluorescence in situ hybridization confirmed RB1 deletions in 2 of 3 cases, and the absence of RB1 deletion in the 4th case that had loss of heterozygosity. All 4 cases showed loss of RB1 protein expression by immunohistochemistry, indicating that RB1 inactivation is important. However, the mechanism of RB1 inactivation appears different than that seen in Merkel cell carcinomas. In addition, copy number variation consistent with activation of the PI3KCA/AKT/mTOR pathway was also observed in all 4 cases. The mTOR pathway may be a potential therapeutic target in these tumors as mTOR inhibitors are currently used to treat other tumor types.

Katabi N, Ghossein R, Ho A, et al.
Consistent PLAG1 and HMGA2 abnormalities distinguish carcinoma ex-pleomorphic adenoma from its de novo counterparts.
Hum Pathol. 2015; 46(1):26-33 [PubMed] Related Publications
Carcinoma ex-pleomorphic adenoma (CA ex-PA) is a malignant salivary gland tumor that arises in association with pleomorphic adenoma (PA). Both PA and CA ex-PA have a broad spectrum of histology, and distinction from their histologic mimics may be difficult based on morphology alone. PLAG1 and HMGA2 abnormalities are the most common genetic events in both PA and CA ex-PA; however, the use of PLAG1 and HMGA2 as adjunct molecular tests has not been well established. Fluorescence in situ hybridization for PLAG1 and HMGA2 was performed on 22 CA ex-PA (10 myoepithelial carcinomas [MECAs], 10 salivary duct carcinomas [SDCs], 1 carcinoma with squamoglandular features, and 1 mixed MECA-adenocarcinoma not otherwise specified), 20 de novo carcinomas (11 MECAs and 9 SDCs), 16 PAs, and 11 PA-histologic mimics. All except 3 CAs ex-PA (86%) were positive for PLAG1 or HMGA2 rearrangements/amplifications. In contrast, 18 (90%) of 20 de novo carcinomas lacked abnormalities in PLAG1 or HMGA2 (P < .01). PLAG1 or HMGA2 rearrangements were identified in 6 (67%) of 9 hypocellular myxoid PAs and in 2 (29%) of 7 cellular PAs. Furthermore, all morphologic mimics of PA were negative for PLAG1 or HMGA2. PLAG1 and HMGA2 rearrangements are the most common genetic events in CA ex-PA regardless of the histologic subtype. Unlike CA ex-PA, de novo carcinomas were negative for PLAG1 and HMGA2. Interestingly, rearrangements of PLAG1/HMGA2 were identified in most hypocellular PAs but only in a small subset of cellular PAs. Fluorescence in situ hybridization for PLAG1 or HMGA2 can be used to distinguish between PA and CA ex-PA and their morphologic mimics.

Chen IC, Chiang WF, Huang HH, et al.
Role of SIRT1 in regulation of epithelial-to-mesenchymal transition in oral squamous cell carcinoma metastasis.
Mol Cancer. 2014; 13:254 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The epithelial-to-mesenchymal transition (EMT) process results in a loss of cell-cell adhesion, increased cell mobility, and is crucial for enabling the metastasis of cancer cells. Recently, the enzyme SIRT1 has been implicated in a variety of physiological processes; however, its role in regulating oral cancer metastasis and EMT is not fully elucidated. Here, we propose a mechanism by which the enzyme sirtuin1 (SIRT1) regulates the EMT process in oral cancer by deacetylating Smad4 and repressing the effect of TGF-β signaling on matrix metalloproteinase-7 (MMP7).
METHODS: The roles of SIRT1 in tumor cell migration/invasion and metastasis to the lungs were investigated using the Boyden chamber assay and orthotopic injections, respectively. RNA interference was used to knockdown either SIRT1 or Smad4 expression in oral squamous cell carcinoma (OSCC) cell lines. Immunoblotting, zymographic assays, and co-immunoprecipitation were used to examine the effects of SIRT1 overexpression on MMP7 expression and activity, as well as on SIRT1/ Smad4 interaction.
RESULTS: We found that compared with normal human oral keratinocytes (HOKs), SIRT1 was underexpressed in OSCC cells, and also in oral cancer tissues obtained from 14 of 21 OSCC patients compared with expression in their matched normal tissues. Overexpression of SIRT1 inhibited migration of OSCC cells in vitro, as well as their metastasis to the lung in vivo. Furthermore, up-regulation of SIRT1 in metastatic OSCCs significantly inhibited the migration and invasion abilities of OSCC cells, while concomitantly increasing the expression of E-cadherin, and decreasing the expressions of mesenchymal markers. We also identified Smad4, a TGF-β-activated transcription factor, as a direct target protein for SIRT1. Overexpression of SIRT1 in OSCC cells led to decreased levels of acetylated Smad4, and inhibition of TGF-β-induced signaling. By associating and deacetylating Smad4, SIRT1 enzyme can influence MMP7 expression, MMP enzyme activity, and consequently, cell migration, invasion, and tumor metastasis in OSCCs.
CONCLUSIONS: These findings provide a valuable insight into the potential role of the SIRT1 enzyme in regulating cell migration and invasion in oral squamous cell carcinoma. Our findings suggest the SIRT1/Smad4/MMP7 pathway as a target for oral cancer driven by EMT.

Abbasi MM, Monfaredan A, Hamishehkar H, Jahanban-Esfahlan R
New formulated "DOX-MTX-loaded nanoparticles" down- regulate HER2 gene expression and improve the clinical outcome in OSCCs model in rat: the effect of IV and oral modalities.
Asian Pac J Cancer Prev. 2014; 15(21):9355-60 [PubMed] Related Publications
BACKGROUND: Oral squamous cell carcinoma (OSCC) remains as one of the most difficult malignancies to control because of its high propensity for local invasion and cervical lymph node dissemination. In this study, we evaluate the efficacy of our novel pH and temperature sensitive doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NP) in affecting HER2 expression profile in OSCC model in rat.
RESULTS: DOX-MTX- nanoparticle complexes caused significant decrease in mRNA level of HER2 compared to untreated cancers (p<0.05) and this finding was more pronounced with the IV mode (p<0.000). Surprisingly, HER2 mRNA was not affected in DOX treated as compared to the control group (p>0.05). On the other hand, in the DOX-MTX NP treated group, fewer tumors characterized with advanced stage and decreased HER2 paralleled improved clinical outcome (P<0.05). Moreover, the effectiveness of the oral route in the group treated with nanodrug accounted for the enhanced bioavailability of nanoparticulated DOX-MTX compared to free DOX. Furthermore, there was no significant difference in mRNA level of HER2 (p>0.05).
CONCLUSIONS: Influence of HER2 gene expression is a new feature and mechanism of action observed only in dual action DOX-MTX-NPs treated groups. Down-regulation of HER2 mRNA as a promising marker and prognosticator of OSCC adds to the cytotoxic benefits of DOX in its new formulation. Both oral and IV application of this nanodrug could be used, with no preferences in term of their safety or toxicity. As HER2 is expressed abundantly by a wide spectrum of tumors, i DOX-MTX NPs may be useful for a wide-spectrum of lesions. However, molecular mechanisms underlying HER2 down regulation induced by DOX-MTX NPs remain to be addressed.

Kolude B, Adisa AO, Lawal AO, et al.
Stoichiometric expression of MMP-2/TIMP-2 in benign and malignant tumours of the salivary gland.
Tumour Biol. 2015; 36(4):2351-7 [PubMed] Related Publications
The aim of this study was to determine the expression of matrix metalloproteinase 2 (MMP-2) and tissue inhibitors of matrix metalloproteinase 2 (TIMP-2) and the MMP-2/TIMP-2 expression ratio in salivary gland tumours (SGTs). Forty-three FFPE SGTs were prepared for antibody processing to MMP-2 and TIMP-2. Two investigators utilizing Sinicrope's method scored the uptake of immuno-stains. Cytoplasmic staining was considered as positive. Data was analysed using SPSS version 20. The significance level was set at p < 0.05. In benign SGTs, the mean score for MMP-2 was not significantly lower than that of TIMP-2 (p = 0.37). However, the mean scores for MMP-2 stain intensity and proportion were significantly higher in malignant than benign SGTs (p = 0.01 and p = 0.02 respectively). There was no significant difference in the mean MMP-2/TIMP-2 expression ratio of the malignant SGTs according to histological grade and histogenesis (p = 0.4 and p = 0.19 respectively). The MMP-2/TIMP-2 expression ratio has a higher prognostic value than the separate expressions of MMP-2 and TIMP-2.

Palve V, Mallick S, Ghaisas G, et al.
Overexpression of Mcl-1L splice variant is associated with poor prognosis and chemoresistance in oral cancers.
PLoS One. 2014; 9(11):e111927 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Altered expression of Mcl-1, an anti-apoptotic member of the Bcl-2 family, has been linked to the progression and outcome of a variety of malignancies. We have previously reported the overexpression of Mcl-1 protein in human oral cancers. The present study aimed to evaluate the clinicopathological significance of the expression of three known Mcl-1 isoforms in oral tumors and the effect of targeting Mcl-1L isoform on chemosensitivity of oral cancer cells.
METHODS: The expression of Mcl-1 isoforms- Mcl-1L, Mcl-1S & Mcl-1ES was analyzed in 130 paired oral tumors and 9 oral cell lines using quantitative real-time PCR & protein by western blotting. The Mcl-1 mRNA levels were correlated with clinicopathological parameters and outcome of oral cancer patients. The effect of Mcl-1L shRNA or Obatoclax (a small molecule Mcl-1 inhibitor), in combination with Cisplatin on chemosensitivity of oral cancer cells was also assessed.
RESULTS: Anti-apoptotic Mcl-1L was predominantly expressed, over low or undetectable pro-apoptotic Mcl-1S and Mcl-1ES isoforms. The Mcl-1L transcripts were significantly overexpressed in all cancer cell lines and in 64% oral tumors versus adjacent normals (P<0.02). In oral cancer patients, high Mcl-1L expression was significantly associated with node positivity (P = 0.021), advanced tumor size (P = 0.013) and poor overall survival (P = 0.002). Multivariate analysis indicated Mcl-1L to be an independent prognostic factor for oral cancers (P = 0.037). Mcl-1L shRNA knockdown or its inhibition by Obatoclax in combination with Cisplatin synergistically reduced viability and growth of oral cancer cells than either treatment alone.
CONCLUSION: Our studies suggest that overexpression of Mcl-1L is associated with poor prognosis and chemoresistance in oral cancers. Mcl-1L is an independent prognostic factor and a potential therapeutic target in oral cancers.

Singh PK, Ahmad MK, Kumar V, et al.
Effects of interleukin-18 promoter (C607A and G137C) gene polymorphisms and their association with oral squamous cell carcinoma (OSCC) in northern India.
Tumour Biol. 2014; 35(12):12275-84 [PubMed] Related Publications
Interleukin-18 (IL-18) is one of the immunomodulatory cytokines that plays an important role in cellular functions against tumor development and progression. IL-18 (-607) C/A and (-0137) G/C gene promoter polymorphisms and their haplotypes variants are associated with risk of various cancers. We evaluated a possible association of IL-18 (-607) C/A and (-137) G/C gene promoter polymorphisms in the susceptibility to oral squamous cell carcinoma (OSCC). A total number of 272 patients with OSCC and 185 healthy volunteers were genotyped for the IL-18 (-607) C/A and (-137) G/C polymorphism. Polymorphism variants were examined by using tetra-primer amplification refractory mutation system (T-ARMS). Genotype frequencies were evaluated by chi-square test and odds ratio (OR) relative risk. IL-18 (-137) G/C gene polymorphism was significantly associated with the risk of OSCC as compared to healthy volunteers (genotype GG vs GC: OR 2.238; 95 % CI 1.455-3.441; p = 0.0003 and allele G vs C: OR 1.984; 95 % CI 1.335-2.947; p = 0.0007). The genotype and allele frequencies of the IL-18 promoter -607 C/A polymorphism in OSCC patients were not significantly different than that in healthy controls (p > 0.05). Our results suggest that IL-18 -137 G/C polymorphism is significantly associated with the progression of oral cancer but -607 C/A polymorphism is not associated with this.

Chen PH, Huang B, Shieh TY, et al.
The influence of monoamine oxidase variants on the risk of betel quid-associated oral and pharyngeal cancer.
ScientificWorldJournal. 2014; 2014:183548 [PubMed] Free Access to Full Article Related Publications
Betel quid (BQ) and areca nut (AN) (major BQ ingredient) are group I human carcinogens illustrated by International Agency for Research on Cancer and are closely associated with an elevated risk of oral potentially malignant disorders (OPMDs) and cancers of the oral cavity and pharynx. The primary alkaloid of AN, arecoline, can be metabolized via the monoamine oxidase (MAO) gene by inducing reactive oxygen species (ROS). The aim of this study was to investigate whether the variants of the susceptible candidate MAO genes are associated with OPMDs and oral and pharyngeal cancer. A significant trend of MAO-A mRNA expression was found in in vitro studies. Using paired human tissues, we confirmed the significantly decreased expression of MAO-A and MAO-B in cancerous tissues when compared with adjacent noncancerous tissues. Moreover, we determined that MAO-A single nucleotide polymorphism variants are significantly linked with oral and pharyngeal cancer patients in comparison to OPMDs patients [rs5953210 risk G-allele, odds ratio = 1.76; 95% confidence interval = 1.02-3.01]. In conclusion, we suggested that susceptible MAO family variants associated with oral and pharyngeal cancer may be implicated in the modulation of MAO gene activity associated with ROS.

Khor GH, Froemming GR, Zain RB, et al.
Screening of differential promoter hypermethylated genes in primary oral squamous cell carcinoma.
Asian Pac J Cancer Prev. 2014; 15(20):8957-61 [PubMed] Related Publications
BACKGROUND: Promoter hypermethylation leads to altered gene functions and may result in malignant cellular transformation. Thus, identification of biomarkers for hypermethylated genes could be useful for diagnosis, prognosis, and therapeutic treatment of oral squamous cell carcinoma (OSCC).
OBJECTIVES: To screen hypermethylated genes with a microarray approach and to validate selected hypermethylated genes with the methylation-specific polymerase chain reaction (MSPCR).
MATERIALS AND METHODS: Genome-wide analysis of normal oral mucosa and OSCC tissues was conducted using the Illumina methylation microarray. The specified differential genes were selected and hypermethylation status was further verified with an independent cohort sample of OSCC samples. Candidate genes were screened using microarray assay and run by MSPCR analysis.
RESULTS: TP73, PIK3R5, and CELSR3 demonstrated high percentages of differential hypermethylation status.
CONCLUSIONS: Our microarray screening and MSPCR approaches revealed that the signature candidates of differentially hypermethylated genes may possibly become potential biomarkers which would be useful for diagnostic, prognostic and therapeutic targets of OSCC in the near future.

PRKD1 mutations characterize salivary gland polymorphous low-grade adenocarcinoma.
Cancer Discov. 2014; 4(11):1255 [PubMed] Related Publications
Salivary gland polymorphous low-grade adenocarcinomas commonly harbor activating PRKD1 mutations.

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