255082

CASC2

C10orf5;cancer susceptibility candidate 2 (non-protein coding);CASC2;cancer susceptibility candidate 2 (non-protein coding)

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10q26.11

ncRNA

"Long non-coding RNAs (lncRNAs) are aberrantly expressed in many diseases including cancer. LncRNA CASC2 (cancer susceptibility candidate 2) has been characterized as a tumor suppressor in endometrial cancer and colorectal cancer. However, the role and function of CASC2 in human gliomas remain unknown. In this study, we confirmed that CASC2 was lowly expressed in glioma tissues as well as in U251 and U87 glioma cell lines. Overexpression of CASC2 inhibited the malignancy of glioma cells, including proliferation, migration, and invasion, and promoted cell apoptosis. microRNA-21 (miR-21) has been reported to be overexpressed in human glioma tissues and cell lines, which is responsible for the malignant progression of glioma. We found that up-regulated CASC2 decreased the expression of miR-21 significantly and there is a reciprocal repression between CASC2 and miR-21 in an Argonaute2-dependent manner. Furthermore, bioinformatics, luciferase reporter assays and pull-down assay confirmed that miR-21 binds to CASC2 in a sequence-specific manner. Introduction of miR-21 largely abrogated CASC2-mediated inhibition of glioma cell proliferation, migration, and invasion, and promotion of cell apoptosis. This study demonstrated that CASC2 plays a tumor suppressive role in glioma via negative regulation of miR-21, which may be a novel therapeutic target for treating gliomas."

"BACKGROUND: Chromosome 10q25-q26 has been strongly correlated to endometrial tumorigenesis. A novel human gene, CASC2, has previously been identified at chromosome 10q26. One out of the three alternative transcripted forms, CASC2a, has been demonstrated to be mutated at a low frequency in endometrial cancer (EC). In this study, the role of the CASC2a gene in cancer has been further defined. MATERIALS AND METHODS: Tumour and corresponding normal tissues were analysed for CASC2a mRNA expression by real-time RT-PCR and mutation status by PCR-based approaches. RESULTS: A significantly decreased level of CASC2a transcripts was observed in 13/17 (76%) EC tissues, as well as in 6/9 (67%) colorectal cancers. Exogenous expression of CASC2a in undifferentiated AN3CA endometrial cancer cells inhibited cellular growth in anchorage-independent growth assays. Finally, infrequent CASC2a mutations were able to impair the gene function. CONCLUSION: Altogether, our findings strongly suggest that CASC2a may act as a tumour suppressor gene, with both epigenetic and genetic alterations concurring to gene inactivation. Down-regulation of CASC2a may provide a growth advantage in EC cells."