Genome wide analysis of chromosomal alterations in oral squamous cell carcinomas revealed over expression of MGAM and ADAM9

Gains of 20q11.21 in human pluripotent stem cells: Insights from cancer research

The genetic abnormalities observed in hPSC cultures worldwide have been suggested to pose an important hurdle in their safe use in regenerative medicine due to the possibility of oncogenic transformation by mutant cells in the patient posttransplantation. One of the best-characterized genetic lesions in hPSCs is the gain of 20q11.21, found in 20% of hPSC lines worldwide, and strikingly, also amplified in 20% of human cancers. In this review, we have curated the existing knowledge on the incidence of this mutation in hPSCs and cancer, explored the significance of chromosome 20q11.21 amplification in cancer progression, and reviewed the oncogenic role of the genes in the smallest common region of gain, to shed light on the significance of this mutation in hPSC-based cell therapy. Lastly, we discuss the state-of-the-art strategies devised to detect aneuploidies in hPSC cultures, avoid genetic changes in vitro cultures of hPSCs, and strategies to eliminate genetically abnormal cells from culture.

Association of Inherited Copy Number Variation in ADAM3A and ADAM5 Pseudogenes with Oropharynx Cancer Risk and Outcome

Inherited copy number variations (CNVs) can provide valuable information for cancer susceptibility and prognosis. However, their association with oropharynx squamous cell carcinoma (OPSCC) is still poorly studied. Using microarrays analysis, we identified three inherited CNVs associated with OPSCC risk, of which one was validated in 152 OPSCC patients and 155 controls and related to pseudogene-microRNA-mRNA interaction. Individuals with three or more copies of ADAM3A and ADAM5 pseudogenes (8p11.22 chromosome region) were under 6.49-fold increased risk of OPSCC. ADAM5 shared a highly homologous sequence with the ADAM9 3'-UTR, predicted to be a binding site for miR-122b-5p. Individuals carrying more than three copies of ADAM3A and ADAM5 presented higher ADAM9 expression levels. Moreover, patients with total deletion or one copy of pseudogenes and with higher expression of miR-122b-5p presented worse prognoses. Our data suggest, for the first time, that ADAM3A and ADAM5 pseudogene-inherited CNV could modulate OPSCC occurrence and prognosis, possibly through the interaction of ADAM5 pseudogene transcript, miR-122b-5p, and ADAM9.

A seven-gene prognosis model to predict biochemical recurrence for prostate cancer based on the TCGA database

Background

The incidence rate of prostate cancer is increasing rapidly. This study aims to explore the gene-associated mechanism of prostate cancer biochemical recurrence (BCR) after radical prostatectomy and to construct a biochemical recurrence of prostate cancer prognostic model.

Methods

The DEseq2 R package was used for the differential expression of mRNA. The ClusterProfiler R package was used to analyze the functional enrichment of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) to explore related mechanisms. The Survival, Survminer, and My.stepwise R packages were used to construct the prognostic model to predict the biochemical recurrence-free probability. The RMS R package was used to draw the nomogram. For evaluating the prognostic model, the timeROC R package was used to draw the time-dependent ROC curve (receiver operating characteristic curve).

Result

To investigate the association between mRNA and prostate cancer, we performed differential expression analysis on the TCGA (The Cancer Genome Atlas) database. Seven protein-coding genes (VWA5B2, ARC, SOX11, MGAM, FOXN4, PRAME, and MMP26) were picked as independent prognostic genes by regression analysis. Based on their Cox coefficient, a risk score formula was proposed. According to the risk scores, patients were divided into high- and low-risk groups based on the median score. Kaplan-Meier plot curves showed that the low-risk group had a better biochemical recurrence-free probability compared to the high-risk group. The 1-year, 3-year, and 5-year AUCs (areas under the ROC curve) of the model were 77%, 81%, and 86%, respectively. In addition, we built a nomogram based on the result of multivariate Cox regression analysis. Furthermore, we select the GSE46602 dataset as our external validation. The 1-year, 3-year, and 5-year AUCs of BCR-free probability were 83%, 82%, and 80%, respectively. Finally, the levels of seven genes showed a difference between PRAD tissues and adjacent non-tumorous tissues.

Conclusions

This study shows that establishing a biochemical recurrence prediction prognostic model comprising seven protein-coding genes is an effective and precise method for predicting the progression of prostate cancer.

Identification of Novel MeCP2 Cancer-Associated Target Genes and Post-Translational Modifications

Abnormal regulation of DNA methylation and its readers has been associated with a wide range of cellular dysfunction. Disruption of the normal function of DNA methylation readers contributes to cancer progression, neurodevelopmental disorders, autoimmune disease and other pathologies. One reader of DNA methylation known to be especially important is MeCP2. It acts a bridge and connects DNA methylation with histone modifications and regulates many gene targets contributing to various diseases; however, much remains unknown about how it contributes to cancer malignancy. We and others previously described novel MeCP2 post-translational regulation. We set out to test the hypothesis that MeCP2 would regulate novel genes linked with tumorigenesis and that MeCP2 is subject to additional post-translational regulation not previously identified. Herein we report novel genes bound and regulated by MeCP2 through MeCP2 ChIP-seq and RNA-seq analyses in two breast cancer cell lines representing different breast cancer subtypes. Through genomics analyses, we localize MeCP2 to novel gene targets and further define the full range of gene targets within breast cancer cell lines. We also further examine the scope of clinical and pre-clinical lysine deacetylase inhibitors (KDACi) that regulate MeCP2 post-translationally. Through proteomics analyses, we identify many additional novel acetylation sites, nine of which are mutated in Rett Syndrome. Our study provides important new insight into downstream targets of MeCP2 and provide the first comprehensive map of novel sites of acetylation associated with both pre-clinical and FDA-approved KDACi used in the clinic. This report examines a critical reader of DNA methylation and has important implications for understanding MeCP2 regulation in cancer models and identifying novel molecular targets associated with epigenetic therapies.

The circEPSTI1/mir-942-5p/LTBP2 axis regulates the progression of OSCC in the background of OSF via EMT and the PI3K/Akt/mTOR pathway

Oral squamous cell carcinoma (OSCC) in the background of oral submucous fibrosis (OSF) caused by areca nut chewing has a high incidence in Asia-Pacific countries. However, the molecular mechanism remains unclear. Here, we performed circRNA microarray analysis to screen the circRNA expression profiles in OSCC and OSF. We identified circEPSTI1 as a circRNA with consistent, sequential upregulation from normal buccal mucosa (NBM) to OSF to OSCC. Functionally, circEPSTI1 significantly promoted OSCC cell proliferation and invasion, as evidenced by the CCK8, colony formation, wound healing, and transwell assays with circEPSTI1 overexpression and silencing. OSCC patients with circEPSTI1^high status exhibited poor prognoses. CircEPSTI1 sponged miR-942-5p and accelerated epithelial-mesenchymal transition (EMT) to increase LTBP2 expression in OSCC through phosphorylation of PI3K/Akt/mTOR signaling pathway components. Blocking the PI3K/Akt/mTOR signaling pathway with the dual PI3k/mTOR inhibitor BEZ235 reversed OSCC progression induced by overexpression of circEPSTI1 and LTBP2. Collectively, these results indicate that the circEPSTI1/miR-942-5p/LTBP2 axis affects OSCC cell proliferation and invasion via the acceleration of EMT and the phosphorylation of PI3K/Akt/mTOR signaling pathway components. CircEPSTI1 may be an independent diagnostic and prognostic marker and a potential therapeutic target for OSCC patients with OSF.

Downregulation of ZC3H14 driven by chromosome 14q31 deletion promotes hepatocellular carcinoma progression by activating integrin signaling

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. Genomic copy number deletion at chromosome 14q31.1-32.13 was frequently observed in HCC; however, the relevant functional target(s) at that locus is not well determined. Here, we performed integrative genomic analyses and identified zinc finger CCCH-type containing 14 (ZC3H14) as a promising candidate at 14q31.1-32.13. We observed frequent copy number deletion (17.1%) and downregulation of ZC3H14 in primary HCC tissues. Downregulation of ZC3H14 was significantly associated with poor outcomes of patients with HCC. Overexpression of ZC3H14 in HCC cell lines significantly suppressed HCC cells growth in vitro and metastasis in vivo. In contrast, RNA interference silencing of ZC3H14 inhibited its tumor-suppressive function. Mechanismly, through combing bioinformatics analyses and experimental investigation, we demonstrated that loss of ZC3H14 promotes HCC progression through enhancing integrin pathway. This study suggests that ZC3H14 functions as a novel tumor suppressor and is a candidate prognostic biomarker for HCC patients.

Genetically-defined novel oral squamous cell carcinoma cell lines for the development of molecular therapies

Emerging biological and translational insights from large sequencing efforts underscore the need for genetically-relevant cell lines to study the relationships between genomic alterations of tumors, and therapeutic dependencies. Here, we report a detailed characterization of a novel panel of clinically annotated oral squamous cell carcinoma (OSCC) cell lines, derived from patients with diverse ethnicity and risk habits. Molecular analysis by RNAseq and copy number alterations (CNA) identified that the cell lines harbour CNA that have been previously reported in OSCC, for example focal amplications in 3q, 7p, 8q, 11q, 20q and deletions in 3p, 5q, 8p, 18q. Similarly, our analysis identified the same cohort of frequently mutated genes previously reported in OSCC including TP53, CDKN2A, EPHA2, FAT1, NOTCH1, CASP8 and PIK3CA. Notably, we identified mutations (MLL4, USP9X, ARID2) in cell lines derived from betel quid users that may be associated with this specific risk factor. Gene expression profiles of the ORL lines also aligned with those reported for OSCC. By focusing on those gene expression signatures that are predictive of chemotherapeutic response, we observed that the ORL lines broadly clustered into three groups (cell cycle, xenobiotic metabolism, others). The ORL lines noted to be enriched in cell cycle genes responded preferentially to the CDK1 inhibitor RO3306, by MTT cell viability assay. Overall, our in-depth characterization of clinically annotated ORL lines provides new insight into the molecular alterations synonymous with OSCC, which can facilitate in the identification of biomarkers that can be used to guide diagnosis, prognosis, and treatment of OSCC.

Overexpression of ADAM9 in oral squamous cell carcinoma

Overexpression of a disintegrin and metalloproteinase 9 (ADAM9) has been shown in various types of cancer. Some studies have reported inconclusive findings regarding chromosomal aberrations in the ADAM9-containing region and ADAM9 expression in oral cancer. Therefore, in this study, ADAM9 protein expression was determined and compared between oral squamous cell carcinoma (OSCC) and normal oral tissues, and between oral cancer cell lines and human oral keratinocytes (HOKs). In total, 34 OSCC and 10 healthy paraffin-embedded tissue sections were probed with an anti-ADAM9 antibody, and the immunohistochemical score was determined by multiplying the percentage of positively stained cells with the intensity score. Four different oral cancer and eight independent HOK cell lines were cultured, and the expression of membrane ADAM9 and active ADAM9 at 84 kDa in these cell lines was assayed by flow cytometry and western blot hybridization, respectively. The results showed that the median immunohistochemical score of ADAM9 expression in OSCC tissues was significantly greater than that in normal tissues (P<0.001). Furthermore, among OSCC cases, intense staining of ADAM9 expression was detected in well-differentiated and in moderately-differentiated OSCC; ADAM9 expression was also correlated with an increased degree of cell differentiation (r=0.557; P=0.001). Expression of membrane ADAM9 was present in 3/4 cancer cell lines. Expression of active ADAM9 varied among all the tested cell lines, but significantly higher ADAM9 expression was present in certain cancer cell lines than those in HOKs (P<0.05). In summary, ADAM9 expression is enhanced in OSCC and oral cancer cell lines, suggesting its role in the pathogenesis of oral cancer. Similar to the overexpression of ADAM9 in well-differentiated prostate cancer, high degrees of ADAM9 expression have also been observed in well-differentiated OSCC.

Genome wide profiling in oral squamous cell carcinoma identifies a four genetic marker signature of prognostic significance

BACKGROUND

Cancers of the oral cavity are primarily oral squamous cell carcinomas (OSCCs). Many of the OSCCs present at late stages with an exceptionally poor prognosis. A probable limitation in management of patients with OSCC lies in the insufficient knowledge pertaining to the linkage between copy number alterations in OSCC and oral tumourigenesis thereby resulting in an inability to deliver targeted therapy.

OBJECTIVES

The current study aimed to identify copy number alterations (CNAs) in OSCC using array comparative genomic hybridization (array CGH) and to correlate the CNAs with clinico-pathologic parameters and clinical outcomes.

MATERIALS AND METHODS

Using array CGH, genome-wide profiling was performed on 75 OSCCs. Selected genes that were harboured in the frequently amplified and deleted regions were validated using quantitative polymerase chain reaction (qPCR). Thereafter, pathway and network functional analysis were carried out using Ingenuity Pathway Analysis (IPA) software.

RESULTS

Multiple chromosomal regions including 3q, 5p, 7p, 8q, 9p, 10p, 11q were frequently amplified, while 3p and 8p chromosomal regions were frequently deleted. These findings were in confirmation with our previous study using ultra-dense array CGH. In addition, amplification of 8q, 11q, 7p and 9p and deletion of 8p chromosomal regions showed a significant correlation with clinico-pathologic parameters such as the size of the tumour, metastatic lymph nodes and pathological staging. Co-amplification of 7p, 8q, 9p and 11q regions that harbored amplified genes namely CCND1, EGFR, TPM2 and LRP12 respectively, when combined, continues to be an independent prognostic factor in OSCC.

CONCLUSION

Amplification of 3q, 5p, 7p, 8q, 9p, 10p, 11q and deletion of 3p and 8p chromosomal regions were recurrent among OSCC patients. Co-alteration of 7p, 8q, 9p and 11q was found to be associated with clinico-pathologic parameters and poor survival. These regions contain genes that play critical roles in tumourigenesis pathways.

Genomic Alteration in Head and Neck Squamous Cell Carcinoma (HNSCC) Cell Lines Inferred from Karyotyping, Molecular Cytogenetics, and Array Comparative Genomic Hybridization

Genomic alteration in head and neck squamous cell carcinoma (HNSCC) was studied in two cell line pairs (HN30-HN31 and HN4-HN12) using conventional C-banding, multiplex fluorescence in situ hybridization (M-FISH), and array comparative genomic hybridization (array CGH). HN30 and HN4 were derived from primary lesions in the pharynx and base of tongue, respectively, and HN31 and HN12 were derived from lymph-node metastatic lesions belonging to the same patients. Gain of chromosome 1, 7, and 11 were shared in almost all cell lines. Hierarchical clustering revealed that HN31 was closely related to HN4, which shared eight chromosome alteration cases. Large C-positive heterochromatins were found in the centromeric region of chromosome 9 in HN31 and HN4, which suggests complex structural amplification of the repetitive sequence. Array CGH revealed amplification of 7p22.3p11.2, 8q11.23q12.1, and 14q32.33 in all cell lines involved with tumorigenesis and inflammation genes. The amplification of 2p21 (SIX3), 11p15.5 (H19), and 11q21q22.3 (MAML2, PGR, TRPC6, and MMP family) regions, and deletion of 9p23 (PTPRD) and 16q23.1 (WWOX) regions were identified in HN31 and HN12. Interestingly, partial loss of PTPRD (9p23) and WWOX (16q23.1) genes was identified in HN31 and HN12, and the level of gene expression tended to be the down-regulation of PTPRD, with no detectable expression of the WWOX gene. This suggests that the scarcity of PTPRD and WWOX genes might have played an important role in progression of HNSCC, and could be considered as a target for cancer therapy or a biomarker in molecular pathology.

Quantitative proteomic analysis for novel biomarkers of buccal squamous cell carcinoma arising in background of oral submucous fibrosis

Background

In South and Southeast Asian, the majority of buccal squamous cell carcinoma (BSCC) can arise from oral submucous fibrosis (OSF). BSCCs develop in OSF that are often not completely resected, causing local relapse. The aim of our study was to find candidate protein biomarkers to detect OSF and predict prognosis in BSCCs by quantitative proteomics approaches.

Methods

We compared normal oral mucosa (NBM) and paired biopsies of BSCC and OSF by quantitative proteomics using isobaric tags for relative and absolute quantification (iTRAQ) to discover proteins with differential expression. Gene Ontology and KEGG networks were analyzed. The prognostic value of biomarkers was evaluated in 94 BSCCs accompanied with OSF. Significant associations were assessed by Kaplan-Meier survival and Cox-proportional hazards analysis.

Results

In total 30 proteins were identified with significantly different expression (false discovery rate < 0.05) among three tissues. Two consistently upregulated proteins, ANXA4 and FLNA, were validated. The disease-free survival was negatively associated with the expression of ANXA4 (hazard ratio, 3.4; P = 0.000), FLNA (hazard ratio, 2.1; P = 0.000) and their combination (hazard ratio, 8.8; P = 0.002) in BSCCs.

Conclusion

The present study indicates that iTRAQ quantitative proteomics analysis for tissues of BSCC and OSF is a reliable strategy. A significantly up-regulated ANXA4 and FLNA could be not only candidate biomarkers for BSCC prognosis but also potential targets for its therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2650-1) contains supplementary material, which is available to authorized users.

Genetic variation and gastric cancer risk: a field synopsis and meta-analysis

BACKGROUND

Data on genetic susceptibility to sporadic gastric carcinoma have been published at a growing pace, but to date no comprehensive overview and quantitative summary has been available.

METHODS

We conducted a systematic review and meta-analysis of the evidence on the association between DNA variation and risk of developing stomach cancer. To assess result credibility, summary evidence was graded according to the Venice criteria and false positive report probability (FPRP) was calculated to further validate result noteworthiness. Meta-analysis was also conducted for subgroups, which were defined by ethnicity (Asian vs Caucasian), tumour histology (intestinal vs diffuse), tumour site (cardia vs non-cardia) and Helicobacter pylori infection status (positive vs negative).

RESULTS

Literature search identified 824 eligible studies comprising 2 530 706 subjects (cases: 261 386 (10.3%)) and investigating 2841 polymorphisms involving 952 distinct genes. Overall, we performed 456 primary and subgroup meta-analyses on 156 variants involving 101 genes. We identified 11 variants significantly associated with disease risk and assessed to have a high level of summary evidence: MUC1 rs2070803 at 1q22 (diffuse carcinoma subgroup), MTX1 rs2075570 at 1q22 (diffuse), PSCA rs2294008 at 8q24.2 (non-cardia), PRKAA1 rs13361707 5p13 (non-cardia), PLCE1 rs2274223 10q23 (cardia), TGFBR2 rs3087465 3p22 (Asian), PKLR rs3762272 1q22 (diffuse), PSCA rs2976392 (intestinal), GSTP1 rs1695 11q13 (Asian), CASP8 rs3834129 2q33 (mixed) and TNF rs1799724 6p21.3 (mixed), with the first nine variants characterised by a low FPRP. We also identified polymorphisms with lower quality significant associations (n=110).

CONCLUSIONS

We have identified several high-quality biomarkers of gastric cancer susceptibility. These data will form the backbone of an annually updated online resource that will be integral to the study of gastric carcinoma genetics and may inform future screening programmes.

Immortalization of epithelial cells in oral carcinogenesis as revealed by genome-wide array comparative genomic hybridization: A meta-analysis

BACKGROUND

This purpose of this meta-analysis study was to identify the most frequent and potentially significant copy number alteration (CNA) in oral carcinogenesis.

METHODS

Seven oral squamous cell carcinoma (OSCC)-related publications, corresponding to 312 samples, were identified for this meta-analysis. The data were analyzed in a 4-step process that included the genome assembly coordination of multiple platforms, assignment of chromosomal position anchors, calling gains and losses, and functional annotation analysis.

RESULTS

Gains were more frequent than losses in the entire dataset. High-frequency gains were identified in chromosomes 5p, 14q, 11q, 7p, 17q, 20q, 8q, and 3q, whereas high-frequency losses were identified in chromosomes 3p, 8p, 6p, 18q, and 4q. Ingenuity pathway analysis showed that the top biological function was associated with immortalization of the epithelial cells (p = 1.93E-04).

CONCLUSION

This study has identified multiple recurrent CNAs that are involved in various biological annotations associated with oral carcinogenesis. © 2015 Wiley Periodicals, Inc. Head Neck 38: E783-E797, 2016.

Collagen Triple Helix Repeat Containing-1 (CTHRC1) Expression in Oral Squamous Cell Carcinoma (OSCC): Prognostic Value and Clinico-Pathological Implications

BACKGROUND

Collagen Triple Helix Repeat Containing 1 (CTHRC1) is a protein often found to be over-expressed in various types of human cancers. However, correlation between CTHRC1 expression level with clinico-pathological characteristics and prognosis in oral cancer remains unclear. Therefore, this study aimed to determine mRNA and protein expression of CTHRC1 in oral squamous cell carcinoma (OSCC) and to evaluate the clinical and prognostic impact of CTHRC1 in OSCC.

METHODS

In this study, mRNA and protein expression of CTHRC1 in OSCCs were determined by quantitative PCR and immunohistochemistry, respectively. The association between CTHRC1 and clinico-pathological parameters were evaluated by univariate and multivariate binary logistic regression analyses. Correlation between CTHRC1 protein expressions with survival were analysed using Kaplan-Meier and Cox regression models.

RESULTS

Current study demonstrated CTHRC1 was significantly overexpressed at the mRNA level in OSCC. Univariate analyses indicated a high-expression of CTHRC1 that was significantly associated with advanced stage pTNM staging, tumour size ≥ 4 cm and positive lymph node metastasis (LNM). However, only positive LNM remained significant after adjusting with other confounder factors in multivariate logistic regression analyses. Kaplan-Meier survival analyses and Cox model demonstrated that patients with high-expression of CTHRC1 protein were associated with poor prognosis and is an independent prognostic factor in OSCC.

CONCLUSION

This study indicated that over-expression of CTHRC1 potentially as an independent predictor for positive LNM and poor prognosis in OSCC.

Identification of multiple DNA copy number alterations including frequent 8p11.22 amplification in conjunctival squamous cell carcinoma

PURPOSE

Little is known about the molecular alterations that drive formation and growth of conjunctival squamous cell carcinoma (cSCC). We therefore sought to identify genetic changes that could be used as diagnostic markers or therapeutic targets.

METHODS

The DNA extracted from 10 snap-frozen cSCC tumor specimens and 2 in situ carcinomas was analyzed using array-based comparative genomic hybridization (aCGH), and further examined with NanoString and quantitative PCR.

RESULTS

The number of regions of DNA loss ranged from 1 to 23 per tumor, whereas gains and amplifications ranged from 1 to 15 per tumor. Most large regions of chromosomal gain and loss were confirmed by NanoString karyotype analysis. The commonest alteration was amplification of 8p11.22 in 9 tumors (75%), and quantitative PCR analysis revealed 100-fold or greater overexpression of ADAM3A mRNA from 8p11.22 locus. In addition, recurring losses were observed at 14q13.2 and 22q11.23, both lost in 5 (42%) of the 12 tumors, and at 12p13.31, lost in 4 (33%) of the 12 samples. Of the eight loci associated with the DNA damage repair syndrome xeroderma pigmentosum, three showed loss of at least one allele in our aCGH analysis, including XPA (9q22.33, one tumor), XPE/DDB2 (11p11.2, one tumor) and XPG/ERCC5 (13q33.1, three tumors).

CONCLUSIONS

Conjunctival SCC contains a range of chromosomal alterations potentially important in tumor formation and growth. Amplification of 8p11.22 and overexpression of ADAM3A suggests a potential role for this protease. Our findings also suggest that defects in DNA repair loci are important in sporadic cSCC.

Overexpression of MMP13 is associated with clinical outcomes and poor prognosis in oral squamous cell carcinoma

Matrix metalloproteinase 13 (MMP13) plays a central role in the MMP activation cascade that enables degradation of the extracellular matrix and basement membranes, and it is identified as a potential driver in oral carcinogenesis. Therefore, this study aims to determine the copy number, mRNA, and protein expression of MMP13 in oral squamous cell carcinoma (OSCC) and to associate these expressions with clinicopathological parameters. Copy number, mRNA, and protein expression analysis of MMP13 were determined using real-time quantitative PCR and immunohistochemistry methods in OSCC samples. The correlations between MMP13 expressions and clinicopathological parameters were evaluated, and the significance of MMP13 as a prognostic factor was determined. Despite discrepancies between gene amplification and mRNA and protein overexpression rates, OSCC cases showed high amplification of MMP13 and overexpression of MMP13 at both mRNA and protein levels. High level of MMP13 protein expression showed a significant correlation with lymph node metastasis (P = 0.011) and tumor staging (P = 0.002). Multivariate Cox regression model analysis revealed that high level of mRNA and protein expression of MMP13 were significantly associated with poor prognosis (P < 0.050). Taken together, these observations indicate that the MMP13 protein overexpression could be considered as a prognostic marker of OSCC.

Upregulated ROS production induced by the proteasome inhibitor MG-132 on XBP1 gene expression and cell apoptosis in Tca-8113 cells

Exposure of Tca-8113 cells to proteasome inhibitor carbobenzoxy-Leu-Leu-leucinal (MG-132) causing apoptosis is associated with endoplasmic reticulum (ER) stress. X-box-binding protein-1 (XBP1) is an important regulator of a subset of genes active during ER stress, which is related to cell survival and is required for tumor growth. The present study is to evaluate the effect of MG-132 on ROS production, XBP1 gene expression, tumor necrosis factor receptor-associated factor 2 (TRAF2), ASK1 and c-jun protein expression in tongue squamous cell carcinoma cell line Tca-8113 cells. ROS production was measured by reactive oxygen species assay. X-box binding protein-1 (XBP1) mRNA was analyzed by real-time-PCR, TRAF2, ASK1 and c-jun protein were investigated by western blot and immunocytochemistry respectively. The result indicated that ROS production, TRAF2, ASK1 and c-jun were elevated in MG-132 treated cells. Giving ROS scavenger N-acetyl-L-cysteine (NAC) largely prevented the effects of MG-132. Furthermore, treating with MG-132 lead to decreased XBP1 mRNA expression but could not completely block the expression of XBP1. Taken together, these findings provide the evidence that MG-132 induced ER stress lead to Tca-8113 cells apoptosis through ROS generation and TRAF2-ASK1-JNK signal pathway activation.

ADAM9 up-regulates N-cadherin via miR-218 suppression in lung adenocarcinoma cells

Lung cancer is the leading cause of cancer death worldwide, and brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker of the epithelial-mesenchymal transition) and ADAM9 (a type I transmembrane protein) are related to lung cancer brain metastasis; however, it is unclear how they interact to mediate this metastasis. Because microRNAs regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9-regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and western blot analysis showed that CDH2 is a target gene of miR-218. MiR-218 was generated from pri-mir-218-1, which is located in SLIT2, in non-invasive lung adenocarcinoma cells, whereas its expression was inhibited in aggressive lung adenocarcinoma. The down-regulation of ADAM9 up-regulated SLIT2 and miR-218, thus down-regulating CDH2 expression. This study revealed that ADAM9 activates CDH2 through the release of miR-218 inhibition on CDH2 in lung adenocarcinoma.

Genomic DNA copy number alterations from precursor oral lesions to oral squamous cell carcinoma

Oral cancer is a multifactorial disease in which both environmental and genetic factors contribute to the aetiopathogenesis. Oral cancer is the sixth most common cancer worldwide with a higher incidence among Melanesian and South Asian countries. More than 90% of oral cancers are oral squamous cell carcinoma (OSCC). The present study aimed to determine common genomic copy number alterations (CNAs) and their frequency by including 12 studies that have been conducted on OSCCs using array comparative genomic hybridization (aCGH). In addition, we reviewed the literature dealing with CNAs that drive oral precursor lesions to the invasive tumors. Results showed a sequential accumulation of genetic changes from oral precursor lesions to invasive tumors. With the disease progression, accumulation of genetic changes increases in terms of frequency, type and size of the abnormalities, even on different regions of the same chromosome. Gains in 3q (36.5%), 5p (23%), 7p (21%), 8q (47%), 11q (45%), 20q (31%) and losses in 3p (37%), 8p (18%), 9p (10%) and 18q (11%) were the most common observations among those studies. However, losses are less frequent than gains but it appears that they might be the primary clonal events in causing oral cancer.