8 research outputs found
miR-198 targets TOPORS: implications for oral squamous cell carcinoma pathogenesis
Get PDFBackgroundmiRNAs play a critical role in the progression of various diseases, including oral squamous cell carcinoma (OSCC), which represents a major health concern and is one of the leading causes for new cancer cases worldwide. The miRNA dysregulation causes havoc and could be attributed to various factors, with epigenetic silencing of tumor suppressor genes being a major contributor to tumorigenesis. In this study, we have explored the tumor suppressive role of miR-198 in OSCC.MethodsThe tumor suppressive effect of miR-198 is established using miRNA analysis in OSCC cell lines, patient samples and xenograft nude mice model. The relationship between the miR-198 and TOPORS is explored using bioinformatics analyses, qRT-PCR, dual-luciferase reporter assay, Western blotting and cancer hall marks assays. The hypermethylation of the MIR198 promoter is confirmed using bisulfite sequencing PCR.ResultsWe have found miR-198 to be upregulated in OSCC cells treated with 5-Azacytidine, a known DNA methyltransferase inhibitor. Upregulation of miR-198 in 5-Azacytidine treated OSCC cells appears to be due to methylation of the MIR198 promoter. Using bioinformatics analysis and dual-luciferase reporter assay, we have identified TOPORS (TOP1 binding arginine/serine rich protein, E3 ubiquitin ligase) as a novel gene target for miR-198. miR-198-mediated repression of TOPORS decreases cell proliferation and anchorage-independent growth and enhances apoptosis of OSCC cells, which is dependent on the presence of the 3′UTR in TOPORS. An inverse correlation between the expression levels of miR-198 and TOPORS is observed in OSCC patient samples, highlighting the biological relevance of their interaction. Delivery of a synthetic miR-198 mimic to OSCC cells results in a significant decrease in xenograft size in nude mice, potentiating its use in therapeutics.ConclusionsThese results suggest that miR-198 is epigenetically silenced in OSCC, which promotes tumor growth, in part, by upregulating the levels of TOPORS
Fine-needle aspiration cytology of salivary gland lesions: A revised classification based on “Milan system”—4years experience of tertiary care cancer center of South India
No full textmiR-617 interacts with the promoter of DDX27 and positively regulates its expression: implications for cancer therapeutics
Get PDFBackgroundPervasive transcription of the eukaryotic genome generates noncoding RNAs (ncRNAs), which regulate messenger RNA (mRNA) stability and translation. MicroRNAs (miRNAs/miRs) represent a group of well-studied ncRNAs that maintain cellular homeostasis. Thus, any aberration in miRNA expression can cause diseases, including carcinogenesis. According to microRNA microarray analyses, intronic miR-617 is significantly downregulated in oral squamous cell carcinoma (OSCC) tissues compared to normal oral tissues.MethodsThe miR-617-mediated regulation of DDX27 is established by performing experiments on OSCC cell lines, patient samples, and xenograft nude mice model. Overexpression plasmid constructs, bisulphite sequencing PCR, bioinformatics analyses, RT-qPCR, Western blotting, dual-luciferase reporter assay, and cell-based assays are utilized to delineate the role of miR-617 in OSCC.ResultsThe present study shows that miR-617 has an anti-proliferative role in OSCC cells and is partly downregulated in OSCC cells due to the hypermethylation of its independent promoter. Further, we demonstrate that miR-617 upregulates DDX27 gene by interacting with its promoter in a dose-dependent and sequence-specific manner, and this interaction is found to be biologically relevant in OSCC patient samples. Subsequently, we show that miR-617 regulates cell proliferation, apoptosis, and anchorage-independent growth of OSCC cells by modulating DDX27 levels. Besides, our study shows that miR-617 exerts its effects through the PI3K/AKT/MTOR pathway via regulating DDX27 levels. Furthermore, the OSCC xenograft study in nude mice shows the anti-tumorigenic potential of miR-617.ConclusionmiR-617-mediated upregulation of DDX27 is a novel mechanism in OSCC and underscores the therapeutic potential of synthetic miR-617 mimics in cancer therapeutics. To the best of our knowledge, miR-617 is the 15th example of a miRNA that upregulates the expression of a protein-coding gene by interacting with its promoter
Study of Biomarker Discordance between Primary and Recurrent Sites and its Clinical Implications in Metastatic Breast Cancer : A Single Institutional Study from India
No full textProteomic Signatures of Diffuse and Intestinal Subtypes of Gastric Cancer
No full textGastric cancer is a leading cause of death from cancer globally. Gastric cancer is classified into intestinal, diffuse and indeterminate subtypes based on histology according to the Laurén classification. The intestinal and diffuse subtypes, although different in histology, demographics and outcomes, are still treated in the same fashion. This study was designed to discover proteomic signatures of diffuse and intestinal subtypes. Mass spectrometry-based proteomics using tandem mass tags (TMT)-based multiplexed analysis was used to identify proteins in tumor tissues from patients with diffuse or intestinal gastric cancer with adjacent normal tissue control. A total of 7448 or 4846 proteins were identified from intestinal or diffuse subtype, respectively. This quantitative mass spectrometric analysis defined a proteomic signature of differential expression across the two subtypes, which included gremlin1 (GREM1), bcl-2-associated athanogene 2 (BAG2), olfactomedin 4 (OLFM4), thyroid hormone receptor interacting protein 6 (TRIP6) and melanoma-associated antigen 9 (MAGE-A9) proteins. Although GREM1, BAG2, OLFM4, TRIP6 and MAGE-A9 have all been previously implicated in tumor progression and metastasis, they have not been linked to intestinal or diffuse subtypes of gastric cancer. Using immunohistochemical labelling of a tissue microarray comprising of 124 cases of gastric cancer, we validated the proteomic signature obtained by mass spectrometry in the discovery cohort. Our findings should help investigate the pathogenesis of these gastric cancer subtypes and potentially lead to strategies for early diagnosis and treatment
Intronic miR-6741-3p targets the oncogene SRSF3: Implications for oral squamous cell carcinoma pathogenesis
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Estrogen receptor, Progesterone receptor, and human epidermal growth factor receptor-2 status in breast cancer: A retrospective study of 5436 women from a regional cancer center in South India
No full textAim: The aim of the study was to analyze the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) status over 7 years in South Indian women with breast cancer. Further analysis of a subgroup was done to study clinically defined subtypes and the role of preanalytical factors in needle core biopsies (NCBs) and excised specimens. Materials and Methods: This was a retrospective study from January 2010 to December 2016. Patients diagnosed with invasive breast cancer and available immunohistochemistry (IHC) reports of ER, PR, and HER2 status were analyzed. The cases for the year 2016 were analyzed further to observe the impact of preanalytical factors on the IHC staining patterns and surrogate status. Results: A total of 5436 patients were included with a median age of 48 years. Among these, 65% were ≤ 55 years. The overall incidence of hormone receptor (HR)-positive patients was 48%; HER2 positive, 15%; and triple-negative breast cancer (TNBC), 37%. The incidence of HR positive, HER2 positive, and TNBC were 45%, 16%, and 39% and 53%, 13%, and 34% in patients <56 years and over 55 years, respectively (P < 0.001). There was an increase in HR positivity and decrease in TNBCs over time. There was no significant difference in the staining patterns in NCBs and excised specimens. Conclusion: With time, there is an increase in hormone-positive tumors which may be attributed to better IHC techniques and tissue handling. There was no statistical difference in the patterns of ER, PR, and HER2 immunostaining in core biopsy and excised specimens
