Pleckstrin Homology Domain Leucine-rich Repeat Protein Phosphatase Acts as a Tumor Suppressor in Oral Squamous Cell Carcinoma.

The pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) family has been found to have both tumor-suppressor and oncogenic properties across various types and locations of cancer. Given that PHLPP has not been previously studied in oral squamous cell carcinoma (SCC), we conducted an assessment of the expression of both its isoforms in oral SCC tissues and cell lines and compared these findings to their corresponding normal counterparts. In addition, we assessed the relationship between PHLPP and clinicopathological factors and patient survival. Quantitative real-time polymerase chain reaction was used to detect the mRNA levels of PHLPP1 and PHLPP2 in cancerous and normal cell lines in addition to 124 oral SCC and noncancerous adjacent epithelia (N = 62, each). Correlations between their expression rate and clinicopathological parameters were further evaluated in 57 patients. Data were statistically analyzed with t test and paired t test, analysis of variance, Mann-Whitney U , and Cox Regression tests ( P < 0.05). We found significantly lower levels of both PHLPP isoforms in oral SCC tissues compared with noncancerous epithelia ( P < 0.001, for both). However, in the cell lines, this difference was significant only for PHLPP1 ( P = 0.027). The correlation between the two isoforms was significant only in cancerous tissues ( P < 0.001). None of the clinicopathologic factors showed significant associations with either of the isoforms and there was no correlation with survival. We showed for the first time that PHLPP1 and PHLPP2 act as tumor suppressors in oral SCC at the mRNA level. The regulation of their mRNA appears to be different between normal and cancerous tissues.

Exploring the interplay between Fusobacterium nucleatum with the expression of microRNA, and inflammatory mediators in colorectal cancer.

Background: Fusobacterium nucleatum has been recognized as an important key bacterium in the cause and spread of colorectal carcinogenesis. Nevertheless, the clinical relevance of F. nucleatum in colorectal cancer (CRC) and its effect on immune factors and the tumor microenvironment have not been fully elucidated. Materials and methods: The frequency of F. nucleatum was measured in 100 paired tumor and normal tissue specimens by TaqMan quantification Real-Time Polymerase Chain Reaction (qPCR). The mRNA expression levels of cytokines (IL-6, IL-10, IL-12ß, IL-17, TNF-α, TLR-2, and TLR-4), and miRNAs (miR-21, miR-31) were examined. Eventually, any potential correlations between the molecular and clinicopathological features of the neoplastic samples and the abundance of F. nucleatum were analyzed. Results: The relative frequency of F. nucleatum was significantly increased in cancerous tissue compared to adjacent non-tumor tissues. Furthermore, the high level of F. nucleatum was significantly associated with histological grade III and IV CRC tissues (P = 0.027 and P = 0.022, respectively) and perineural invasion-positive patients (P = 0.037). In addition, the expression levels of IL-6, IL-17, TNF-α,IL-12ß, TLR-2, and TLR-4 as well as miR-21 and miR-31 showed a significant increase in the cancer group. A notable correlation was also observed between the high status of F. nucleatum and the expression of IL-6, TNF-α and miR-21. Conclusion: Our results emphasize the importance of F. nucleatum and changes in the expression of genes involved in CRC. Studying the microbial profile and gene expression changes in CRC patients may be a promising approach to improve screening methods and provide therapeutic strategies.

Molecular mechanisms of miR-1236 in the assessment of tumor lymphangiogenesis in human ovarian cancer patients.

BACKGROUND: Tumor lymphangiogenesis is a critical component in the progression of cancers and specific microRNAs have been reported to be implicated in this process. Recent studies revealed the involvement of miR-1236 in lymphangiogenic signaling by targeting vascular endothelial growth factor receptor 3 (VEGFR3). However, the prognostic importance of miR-1236 and its clinical relevance for lymphangiogenesis in ovarian cancer (OC) remains unclear. METHODS: The study included 52 ovarian tumors and 28 normal ovarian tissues. Quantitative real-time PCR was utilized to analyze the VEGFR3, VEGF-C, LYVE-1 and PROX1 mRNA expression as well as miR-1236. VEGFR3 protein expression was measured by immunohistochemistry staining. Immunohistochemistry for the podoplanin marker (D2-40) was performed to measure lymphatic vessel density (LVD). In addition, diagnostic evaluation based on the receiver-operating characteristic (ROC) curve was performed. The influence of miR-1236 on overall survival was evaluated by Kaplan-Meier method. RESULTS: Here, we show that miR-1236 expression was significantly decreased in ovarian tumors compared with control tissues (p < 0.001) and correlated with advanced clinical stage, lymph node metastasis, distant metastasis and patient survival (All P < 0.05). Moreover, in ovarian tumors, LVD as well as the gene expression of VEGFR3, VEGF-C and LYVE-1, but not PROX1, were found to be remarkably higher compared with control tissues. We also detected a more robust positive staining for VEGFR3 in OC tissues than in control tissues. Furthermore, our results demonstrated an inverse association of miR-1236 expression with LVD, VEGFR3, LYVE-1 and PROX1 expression in OC tissues. The ROC curve analysis indicated that miR-1236 expression has the potential to be used as a diagnostic and prognostic biomarker in OC. Survival analysis further verified a lowered overall survival rate in patients with low miR-1236 expression than in those with high expression. CONCLUSIONS: Our results provide evidence for the translational involvement of miR-1236 in the lymphangiogenesis of OC by regulating lymphangiogenesis-related factors and support the clinical importance of miR-1236 as a new diagnostic and prognostic biomarker for OC.

Association between the Expression Levels of MicroRNA-101, -103, and -29a with Autotaxin and Lysophosphatidic Acid Receptor 2 Expression in Gastric Cancer Patients.

Background: Gastric cancer (GC) is regarded as the most prevalent malignancy with the high mortality rate, worldwide. However, gastroscopy, a biopsy of suspected sample, and detecting CEA, CA19-9, and CA72-4 are presently used, but these diagnostic approaches have several limitations. Recently, microRNAs as the most important member of noncoding RNAs (ncRNAs) have received attention; recent evidence demonstrates that they can be used as the promising candidate biomarkers for GC diagnosis. We aimed to investigate the association between the microRNA-29a, -101, and -103 expression and autotaxin (ATX) and lysophosphatidic acid receptor 2 (LPA2) expression in GC patients. Material and Methods. The present study was conducted on 40 paired samples of primary GC tissue and adjacent noncancerous tissue. The gene expression levels of miR-101, -103, -29, ATX, and LPA2 were analyzed by quantitative reverse-transcription PCR (qRT-PCR). Besides, the protein levels of ATX and LPA2 were evaluated using western blot. Results: The expression levels of miR-29 and miR-101 were significantly lower (p value < 0.0001), but the miR-103 and LPA2 were significantly higher in gastric tumor samples compared to the corresponding nontumor tissues (p value < 0.0001). Moreover, the diagnostic accuracy of miRs to discrimine the GC patients from noncancerous controls was reliable (miR-101, sensitivity: 82.5% and specificity: 85%; miR-103, sensitivity: 72.5% and specificity: 90%; miR-29, sensitivity: 77.5% and specificity: 70%). Conclusion: It seems that determining the expression level of miR-101, -103, and -29, as the novel diagnostic biomarkers, has diagnostic value to distinguish GC patients from healthy individuals.

Aberrant methylation of miR-124 upregulates DNMT3B in colorectal cancer to accelerate invasion and migration.

The dysregulation of microRNA expression is significantly associated with the initiation and development of CRC. miR-124 is markedly downregulated in colorectal cancer. In the present study, the effects of methylation, over expression and downregulation of miR-124 and its target gene DNMT3B on the proliferation, migration and invasion of colorectal cell line were investigated. The promoter methylation status of miR-124 in the CRC was investigated by methylation specific PCR (MSP). The potential role of miR-124 expression in CRC cells was investigated using the demethylation reagent 5-Aza-CdR and transfection of miR-124 mimic/antimir. MSP revealed that miR-124 promoter region was hypermethylated, result in its significant downregulation in tumour tissues. We showed miR-124 expression was upregulated following 5-AZA-CdR treatment. Transfected Hct-116 cell line with miR-124 leads to decreased DNMT3B expression, cell proliferation, migration and invasion of HCT-116. In conclusion, our data indicate that miR-124 suppress colorectal cancer proliferation, migration and invasion through downregulating DNMT3B level.

PAX2 promoter methylation and AIB1 overexpression promote tamoxifen resistance in breast carcinoma patients.

INTRODUCTION: Disease recurrence is an important obstacle in estrogen receptor positive (ER+) tamoxifen treated breast carcinoma patients. Tamoxifen resistance-related molecular mechanisms are not fully understood. Alteration in DNA methylation which contributes to transcriptional regulation of cancer-related genes plays a crucial role in tamoxifen response. In the present study, the contribution of promoter methylation and mRNA expression of PAX2 and AIB1 in the development of breast carcinoma and tamoxifen refractory was assessed. METHODS: Methylation specific-high resolution melting (MS-HRM) analysis and Real-time quantitative PCR (RT-qPCR) experiment were performed to analyze the promoter methylation and mRNA expression levels of PAX2 and AIB1 genes in 102 breast tumors and adjacent normal breast specimens. RESULTS: We indicated that PAX2 expression is decreased in breast tissues due to hypermethylation in its promoter region. Compared to the adjacent normal tissues, the tumors exhibited significantly lower relative mRNA levels of PAX2 and increased expression of AIB1. Aberrant promoter methylation of PAX2 and overexpression of AIB1 was observed in tamoxifen resistance patients compared to the sensitive ones. Cox regression analysis exhibited that the increased promoter methylation status of PAX2 and overexpression of AIB1 remained as unfavorable identifiers which influence patients' survival independently. CONCLUSIONS: Our results revealed that the aberration in PAX2 promoter methylation and AIB1 overexpression are associated with the tamoxifen response in breast carcinoma patients. Further research is needed to demonstrate the potential of using PAX2 and AIB1 expression and their methylation-mediated regulation as predictive or prognostic biomarkers or as a new target therapy for better disease management.

HE4, A New Potential Tumor Marker for Early Diagnosis and Predicting of Breast Cancer Progression.

BACKGROUND & OBJECTIVE: This study examined the potential of human epididymis protein 4 (HE4) as a marker in early diagnosis or as a prognostic factor for breast cancer (BC) patients. METHODS: A total of 31 patients diagnosed with BC were enrolled in the study between 2008 and 2018. The mRNA and protein expression levels of HE4 were analyzed by immunohistochemistry (IHC) and real-time polymerase chain reaction (PCR) in the BC tissue and the non-tumoral adjacent tissue. Using ELISA technique, HE4 plasma levels were also measured in 43 BC patients compared to 43 healthy individuals. The correlation between HE4 expression and clinicopathological features was then investigated. RESULTS: An increase in HE4 expression was observed at mRNA and protein levels in the BC group compared to the control group (P<0.01, P<0.0001, respectively). In addition, the relative expression of HE4 mRNA in BC patients showed a significant correlation with the differentiation grade of cancer cells (P<0.001). Plasma levels of HE4 was also associated with grade (P<0.0001), stage, and tumor size in BC patients (for both P<0.01). Patients with metastatic BC (P<0.01), lymphatic invasion, and lymph node involvement (for both P<0.05) showed significantly higher plasma levels of HE4 expression than patients without metastasis. CONCLUSION: According to our findings, upregulation of HE4 may be related to invasive BC phenotype. Measuring plasma levels of HE4 could be useful as a screening test in early diagnosis of BC.

The Frequency of Human Papillomavirus Positivity in Iranian Patients with Head and Neck Squamous Cell Carcinoma.

BACKGROUND & OBJECTIVE: Human papillomavirus (HPV) has been associated with prognosis in patients with head and neck squamous cell carcinoma (HNSCC). Similar to the global studies, different prevalence rates of this viral infection have been reported in Iran. Therefore, we aimed to report the prevalence of this virus and its significance in HNSCC patients. METHODS: Patients who were referred to the five hospitals of Tehran city from May 2018 to May 2019 were enrolled in this study. All patients were diagnosed with HNSCC based on pathologic study. The pathologic disease staging was defined, and DNAs were extracted from the fresh tissue samples via kits. After polymerase chain reaction (PCR), HPV positive samples were evaluated for determining genotypes and data analysis. RESULTS: Of the 46 patients, three patients (6.5%) showed positive HPV results with the following subtypes: 18 (in two patients), 52 (in three patients), 61 (in two patients), 67, and 73.Comparison of variables between the groups with and without HPV showed a significant difference based on the tumor's lymphatic invasion (P=0.041), peripheral lymph node involvement (P=0.008), and histologic grade (P=0.011), but no statistically significant difference in terms of other variables such as age, primary tumor site, size, pathologic stage, vascular or perineural invasion, metastasis, smoking, and alcohol consumption was found.

An integrated analysis to predict micro-RNAs targeting both stemness and metastasis in human gastric cancer.

BACKGROUND AND AIM: Cancer stem cells (CSCs), a subpopulation of tumor cells, assess the capacity of self-renewal, metastasis, and therapeutic resistance. Regulation of CSCs and their epithelial to mesenchymal transition (EMT) potential is one of the promising strategies to eliminate cancer or to inhibit metastasis. Micro-RNAs (miRNAs) as regulators of several cell properties, such as self-renewal, metastasis, and resistance to the drug, could be proper targets in cancer diagnosis and therapy. The aim of the present study is to select common miRNAs targeting both self-renewal and metastasis in gastric cancer. METHODS: Stemness-related and EMT-related genes were selected by literature mining. The common miRNAs targeting genes were chosen using different databases and r programming language. The expression pattern of selected miRNAs and genes was evaluated in gastrospheres-as a gastric CSC model-and gastric tumor biopsies. RESULTS: Based on the integrated analysis, six miRNAs common to both stemness and metastasis were identified. miR-200c-3p and miR-520c-3p overexpressed in MKN-45 gastrospheres and grade III tumors. In AGS spheres, however, miR-520c-3p and miR-200c-3p upregulation and miR-34a-5p downregulation were similar to grade II tumors. Interestingly, miR-200c-3p and miR-520c-3p indicated a positive correlation with OCT4 and NOTCH1 expression in grade III tumors and MKN-45 spheres. Protein-protein network revealed that the EMT acquisition can be induced by stemness activation through intermediated core-regulatory genes, including CTNNB1, CTNND1, MAML1, KAT2A, and MAML3. CONCLUSION: The upregulation of mir-200c-3p and mir-520c-3p could effect on stemness and metastasis in gastric cancer as well as gastric CSCs. Therefore, they can be used as diagnosis and prognostic factors.

Involved microRNAs in alternative polyadenylation intervene in breast cancer via regulation of cleavage factor "CFIm25".

Cleavage factor "CFIm25", as a key repressor at proximal poly (A) site, negatively correlates to cell proliferation and tumorigenicity in various cancers. Hence, understanding CFIm25 mechanism of action in breast cancer would be a great benefit. To this aim four steps were designed. First, potential miRNAs that target 3'-UTR of CFIm25 mRNA, retrieved from Targetscan web server. Second, screened miRNAs were profiled in 100 breast cancer and 100 normal adjacent samples. Third, miRNAs that their expression was inversely correlated to the CFIm25, overexpressed in MDA-MB-231 cell line, and their effect on proliferation and migration monitored via MTT and wound healing assays, respectively. Fourth, interaction of miRNAs of interest with 3'-UTR of CFIm25 confirmed via luciferase assay and western blot. Our results indicate that CFIm25 considerably down-regulates in human breast cancer tissue. qRT-PCR assay, luciferase test, and western blotting confirm that CFIm25 itself could be directly regulated by oncomiRs such as miR-23, -24, -27, -135, -182 and -374. Besides, according to MTT and wound healing assays of cell lines, CFIm25 knockdown intensifies cell growth, proliferation and migration. Our results also confirm indirect impact of CFIm25 on regulation of mRNA's 3'-UTR length, which then control corresponding miRNAs' action. miRNAs directly control CFIm25 expression level, which then tunes expression of the oncogenes and tumor proliferation. Therefore, regulation of CFIm25 expression level via miRNAs is expected to improve treatment responses in breast cancer.

Association of High Expression Levels of SOX2, NANOG, and OCT4 in Gastric Cancer Tumor Tissues with Progression and Poor Prognosis.

BACKGROUND: Expression of the essential regulator genes, SOX2, NANOG, and OCT4, so-called as stemness factors, is prerequisite for the tumorigenic capability of cancer stem cells (CSCs) and their potential role in the formation and progression of various human cancers. METHODS: In this study, the expression levels of SOX2, NANOG, and OCT4 were quantified by a qRT-PCR method in 100 gastric cancer tumor tissues vs the paired adjacent normal tissues. Then, the relationship between the expression of the three genes in gastric cancer tumor tissues and the clinicopathological characteristics and overall survival of patients was investigated. RESULTS: Higher expression levels of SOX2, NANOG, and OCT4 were found in gastric cancer tumor tissues compared with those in paired adjacent normal tissues (P = 0.0001). Overexpression of the mentioned genes in gastric cancer tumor tissues was resolved to be significantly associated with tumor size (P < 0.05), TNM stage (P = 0.001), tumor grade (P < 0.01), and shortened overall survival time (P = 0.0001). CONCLUSIONS: These findings indicted that the stemness factors SOX2, NANOG, and OCT4 are significantly overexpressed in gastric cancer and may serve as potential biomarkers of gastric cancer progression and prognosis.

Association of MAPK and its regulatory miRNAs (603, 4301, 8485, and 4731) with the malignant transformation of oral lichen planus.

Oral lichen planus (OLP) is a potentially malignant oral lesion that may transform into oral squamous cell carcinoma (OSCC). The purpose of this study was to assess the level of expression of MAPK/ERK1/2 gene, and microRNA (miR)-603, 4301, 8485, and 4731 in the MAPK signaling pathway in OLP and OSCC lesions. This case-control study evaluated 26 OSCC, 20 OLP and 20 healthy control tissue specimens. After RNA extraction, the respective miRNA and MAPK/ERK1/2 mRNA levels were assessed by quantitative reverse transcription polymerase chain reaction (RT-PCR). Significant upregulation of MAPK/ERK1/2 gene was noted in the OLP and OSCC specimens compared with healthy controls (p < 0.001). The expression level of miR-4731 was significantly lower in the OLP and OSCC specimens than in the healthy specimens (p < 0.001). The expression of MiR-603 was the lowest in OLP, followed by OSCC and then the control group (p < 0.001). No significant difference was found in miR-4801 levels between OSCC and OLP specimens compared with healthy controls (p = 0.43 and p = 0.86, respectively). In addition, a non-significant decrease in miR-8485 levels was noted in the OSCC and OLP specimens compared with healthy controls (p = 0.98 and p = 0.61, respectively). A significant decrease in level of miR-603 was noted in OLP compared with OSCC group (p < 0.001). The miR-4801 and miR-8485 expression levels were directly correlated with MAPK/ERK1/2 mRNA expression (p = 0.01). Higher expression level of MAPK/ERK1/2, miR-603, miR-4801, and miR-4731, and lower expression level of miR-8485 were correlated with significantly lower overall survival rate in OSCC patients. The increased expression of MAPK/ERK1/2 and decreased expression of miR-603 and miR-4731 are associated with greater risk of OLP malignant transformation and poor histopathological characteristics of OSCC.

Differential Expression Pattern of Epithelial Mesenchymal Transition Gens: AXL, GAS6, Claudin-1, and Cofilin-1, in Different Stages of Epithelial Ovarian Cancer.

BACKGROUND: Epithelial ovarian cancer (EOC), is the fatal form of gynecological cancer. Almost 70% of ovarian cancer patients are detected at an advanced stage (III-IV) with metastases. Epithelial-mesenchymal transition (EMT) is a critical process associated with metastasis. This study investigated the expression levels of AXL, GAS6, Claudin-1, and Cofilin-1, as genes involved in EMT in relation to clinicopathologic features in ovarian cancer patients. METHODS: In this descriptive study, 78 ovarian epithelial cancer patients were enrolled. Samples were provided by the Iran National Tumor Bank, founded by the Cancer Institute of Tehran University of Medical Sciences in 2017. The expression levels of AXL, GAS6, Claudin-1, and Cofilin-1 genes were investigated in a fresh, frozen tumor sample and normal adjacent tissue by real-time PCR (RT-PCR). RESULTS: Findings showed a significant relationship between the overexpression of AXL and TNM staging (P=0.03). The expression level of GAS6 decreased in more advanced stages (P=0.01). There is a negative relationship between Cofilin-1 expression level and TNM staging (P=0.002). Claudin-1 expression level was higher in low stages compared with that in high stages (P=0.01). There was no relationship between gene expression levels of target genes with size and grade of the tumor. CONCLUSION: Given the importance of these genes in EMT, alteration in their expression pattern can contribute to the progression of the disease and distant metastasis of cancer cells. Additionally, knowing the alteration pattern of these genes expression can help to better understanding and prediction of the prognosis of EOC.

A retrospective institutional study of histopathologic pattern of Oral Squamous Cell Carcinoma (OSCC) in Tehran, Iran during 2006-2015.

BACKGROUND: Despite the available data on demographic information of oral squamous cell carcinoma (OSCC), the changing trend of histopathologic pattern of OSCC has not conducted yet, in Iran. The aim was to investigate the pattern of histopathologic features of OSCC in Iran by analyzing the patients referred to Cancer Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran, during 2006-2015. MATERIALS AND METHODS: The study was a retrospective institutional study. The pathology records with the diagnosis of OSCC were retrieved from Iran National Tumor Bank, Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran, during 2006-2015. The demographic characteristics and histopathologic features were recorded and analyzed for possible trend. Descriptive analysis was used for statistical interpretation. RESULTS: The data showed an increasing number of moderately and poorly differentiated OSCC. Accordingly, higher increasing rate in tumor size and vascular, perineural invasion was detected. CONCLUSION: On the basis of histopathologic features, moderately differentiated OSCC with increasing rate of tumor size and vascular, perineural invasion was indicated in recent decade. Based on the findings, lower differentiation potentially is compatible with worsen prognosis.

The insulin-like growth factor binding protein-3 and its death receptor in pancreatic ductal adenocarcinoma poor prognosis.

Insulin-like growth factor binding protein-3 (IGFBP-3) and its newly discovered death receptor (IGFBP-3R) have been reported to involve in a wide variety of cancers. However, their role in pancreatic ductal adenocarcinoma (PDAC) has not been elucidated yet. Here, 478 pancreatic cancers were screened for primary PDAC tumors. The samples were evaluated using quantitative reverse-transcriptase polymerase chain reaction, western blotting, and immunohistochemistry staining. The results indicated that relative IGFBP-3 mRNA expression and its protein level were reduced stage dependently in the PDAC tumors (p < .001 and p < .05, respectively). The subcellular distribution of IGFBP-3 was mainly nuclear only in Stage 0 + 1 (about 150% compared to adjacent normal tissues [p < .05]). The value for IGFBP-3R messenger RNA (mRNA) and protein were also reduced in tumors in compared to adjacent normal pancreatic tissues (p < .05). The Kaplan-Meier analysis also showed that mRNA expression of IGFBP-3 and IGFBP-3R was positively associated with survival, (p = .001). In addition, there is a strong association between low expression of IGFBP-3 and tumor size (p = .032), the lymphatic invasion (p = .001), the TNM (tumor, node, metastasis) staging (p = .001), tumor differentiation (p = .001), and PNI status (p = .021). Down-regulation of IGFBP-3R was also correlated with the tumor size (p = .01), the lymphatic invasion (p = .012) TNM staging (p = .001), tumor differentiation (p = .021) and PNI status (p = .038). In conclusion, IGFBP-3 and its receptor were down-regulated and their expression was associated with poor prognosis of PDAC.

The Relation between Polymorphisms in Exon 5 and Exon 6 of GSTP1 Gene and the Risk of Lung Cancer in Iranian People

Objective: The GSTP1 gene, which is located on chromosome 11q13, consists of 7 exons and 6 introns. There are two polymorphisms in GSTP1 that have been exposed to a transposition for codon 105 (Ile/Val) and 114 (Ala/Val) in exons 5 and 6, which have been studied previously in relation to lung cancer. Since the level of GSTP1 expression in lung tissues and other human epithelial tissues is high, GSTP1Val-105 polymorphism is recognized as a sensitive factor for tobacco-related cancers, especially lung cancer. Methods: One hundred and twenty tissue block samples of patients with lung cancers and 120 peripheral blood samples of the control group were obtained from two referral cancer centers in Tehran, Iran, from 2011 to 2016. Genomic DNA was extracted from tissue blocks and buffy coat of study cases to detect SNP of GSTP1 gene using Tetra-primer ARMS-PCR. Results: There was a notable correlation between the incidence of lung cancer and variant Val105 (P-value=0.001; OR=2/6; 95% CI=1.49-4.53) and Ile105 (P-value=0.003; OR=0.41; 95% CI=0.23-0.73). The odds ratio for lung cancer in the homozygous Ile105/Ile105 genotype was 3.56 times higher than that of individual with heterozygous Ile105/Val105 (P-value<0.001; OR=3/56; 95% CI=1.826-6.934) genotype, that was statistically significant. Furthermore, the results showed that there was no significant correlation between Ala114/Val114 genotypes and lung cancer. The BC (P-value=0.007; OR=0.16; 95% CI=0.04-0.61) and AA (P=0.001) genotypes were statistically significant (P-value <0.05); and for those who had AA genotype, the odds ratio was almost six times higher than those with BC genotype. Conclusions: The study of GSTP1 polymorphisms indicated that unlike the polymorphism in exon 5, the GSTP1 exon 6 polymorphism correlated with the lung cancer risk in the select group of Iranian people. Likewise, the potential use of this genetic polymorphism as a lung cancer predictor is confirmed.

MicroRNA-203 reinforces stemness properties in melanoma and augments tumorigenesis in vivo.

One of the challenges encountered in microRNA (miRNA) studies is to observe their dual role in different conditions and cells. This leads to a tougher prediction of their behavior as gene expression regulators. miR-203 has been identified to play a negative role in the progression of malignant melanoma; however, it has been reported, with dual effect, as both an oncomiR and tumor suppressor miRNA in some malignancies, such as breast cancer, meanwhile, the role of miR-203 in melanoma stem cells or even metastatic cells is unclear. In the present study, after observation of upregulation of miR-203 in melanoma patient's serum and also melanospheres as cancer stem cells model, we examined its overexpression on the stemness potential and migration ability of melanoma cells. Our data demonstrated that the increased miR-203 level was significantly associated with significant increase in the ability of proliferation, colony and spheres formation, migration, and tumorigenesis in A375 and NA8 cells. All of these changes were associated with enhancement of BRAF, several epithelial to mesenchymal transition factors, and stemness genes. In conclusion, our results clearly determined that miR-203 could be down-regulateddownregulated in melanoma tissues but be overexpressed in melanoma stem cells. It has an important role as oncomiR and promote repopulation, tumorigenicity, self-renewal, and migration. Therefore, we suggested overexpression of miR-203 as biomarker for early detection of metastasis. However, more studies are needed to validate our data.

PTEN and miR-26b: Promising prognostic biomarkers in initiation and progression of Oral Squamous Cell Carcinoma.

BACKGROUNDS: Oral Squamous Cell Carcinoma (OSCC) is the most common malignancy of the oral cavity. Phosphatase and TENsin homolog (PTEN) is a well-known tumor suppressive gene regulated by several biomarkers including a small single-stranded molecule, microRNA26b (miR-26b). Here, we studied the expression of PTEN and miR-26b in OSCC specimens in comparison with adjacent normal mucosa. METHODS: The expressions of PTEN and miR-26b genes were evaluated at mRNA level in OSCC and adjacent normal fresh frozen tissues in 49 patients using Quantitative Real-Time PCR and analyzed their associations with clinicopathological factors. RESULTS: The expression level of PTEN was significantly lower in OSCC specimens comparing with adjacent normal tissues (P-value = 0.000). The expression of PTEN was associated with T stage (P-value = 0.006) and N stage (P-value = 0.043). A nonsignificant decrease in miR-26b expression level was also observed in OSCC tissues. Additionally, in patients with more aggressive tumoral behavior, including vascular invasion (P-value = 0.012) and positive N stage (P-value = 0.02), significant decreases were found. CONCLUSIONS: These findings suggest that inactivation of PTEN may have an impact on initiation and progression of OSCC. Additionally, miR-26b might have a tumor suppressive role in OSCC.

Expression and clinicopathological significance of DNA methyltransferase 1, 3A and 3B in tamoxifen-treated breast cancer patients.

Progression of tamoxifen resistance remained as a crucial obstacle to treatment of estrogen receptor positive breast carcinoma patients. Recent studies demonstrated the importance of DNA methylation pattern on tamoxifen refractory. This study aimed to investigate the protein expression pattern and clinicopathological significance of DNA methyltransferase 1, 3A and 3B, as leading factors in regulation of DNA methylation process, in breast carcinoma patients with adjuvant tamoxifen therapy. Seventy two Formalin-Fixed Paraffin-Embedded (FFPE) breast tumor tissues of tamoxifen sensitive (TAMS) and tamoxifen resistance (TAM-R) patients were recruited for immunohistochemical experiments. DNMT1, DNMT3a, and DNMT3b expressions were observed in 86, 72.2 and 100% of tamoxifen resistance patients, respectively. Data analysis indicated that DNMTs were overexpressed in TAM-R tumors (P < 0.05). In TAM-S subgroup, DNMT1, DNMT3A and DNMT3B expression was associated with high histologic grade (P = 0.049, P = 0.01 and P = 0.02, respectively). DNMT3B expression was also correlated with lymphatic invasion (P = 0.034). In TAM-R subgroup, DNMT1 expression associated with extracapsular nodal extension (P = 0.019). DNMT3A and DNMT3B expression showed a significant association with high histologic grade (P = 0.001) and DNMT3A expression was also associated with HER-2 status (P = 0.027). Cox proportional hazard model demonstrated that overexpression of DNMT3B remained as an independent and unfavorable prognostic factor for disease free survival (P < 0.001). Taken together, these results suggest that DNMTs could be an effective factor in development of tamoxifen resistance in breast tumors.

Altered DNA methyltransferases promoter methylation and mRNA expression are associated with tamoxifen response in breast tumors.

Tamoxifen is a standard anti-hormone treatment in estrogen receptor positive breast carcinoma patients. Unfortunately, about 50% of patients relapse during treatment. Promoter hypermethylation contributes to the epigenetic modulation of tamoxifen resistance-related genes. To evaluate the contribution of DNMTs expression and their promoter methylation as diagnostic biomarkers in development of breast malignancy and tamoxifen resistance, the present study was designed and 107 breast tumors and normal breast tissues were recruited. Methylation-specific high-resolution melt curve analysis and quantitative RT-PCR were performed to evaluate DNMTs promoter methylation and mRNA expression, respectively. Our results indicated that DNMT3A and DNMT3B promoters were demethylated in breast tumors as compared to control tissues. The mRNA expression levels of all three DNMTs were significantly increased in tumor specimens in comparison to control tissues (p < 0.05). Among tumor tissues, DNMT3A promoter methylation was significantly higher in tamoxifen sensitive patients (p = 0.001). Overexpression of DNMT3A (p = 0.037) and DNMT3B (p < 0.001) mRNA were observed in tamoxifen resistance group. Multivariate logistic regression analysis indicated that low methylation status of DNMT3A and overexpression of DNMT3B could be as independent predictors of disease recurrence. Multivariate Cox regression analysis, revealed that high methylation status of DNMT3A could be an independent and favorable predictor for disease free survival (p = 0.002) and overall survival (p = 0.026); high expression of DNMT1 (p = 0.03) remained significant and unfavorable predictive factor for overall survival. In conclusion, our data for the first time indicated that low methylation status of DNMT3A promoter and overexpression of DNMT3B could contribute to disease recurrence in tamoxifen-treated breast cancer patients.