No abstract

In most human primary cancers, the expression, or telomerase activity, of telomerase reverse transcriptase (TERT) is detectable. However, the mechanism ofTERTactivity within oncogenesis of thyroid cancer remains largely unknown. In this study, we identified miR-195-5p as having involvement in cell proliferation, apoptosis, and invasion in human thyroid cancer. MTT was used to measure cell proliferation, Transwell chamber was used to measure invasion. Western blotting was used to detect the expressions of TERT, PCNA, and Ki67. Target gene prediction software predicted that TERT may be the target gene of miR-195-5p. Luciferase reporting system was used to identify the targeting relationship. A significant increase of in TERT expression was observed by immunohistochemistry compared with normal tissue, however, a decrease in miR-195-5p expression using qRT-PCRand western blot compared with normal cells. Functional analysis demonstrates that miR-195-5p negatively correlated withTERTand inhibitedTERTexpression through its interaction with theTERT3ʹ-untranslatedregion (3ʹ-UTR). Overexpression of miR-195-5p was shown to inhibit proliferation and invasion, and promote apoptosis of CAL-62 thyroid cancer cells. miR-195-5p-mediatedeffects were rescued by the overexpression ofTERT. Altogether, our data demonstrate that miR-195-5p regulates cell proliferation, apoptosis, and invasion in human thyroid cancer viaTERT, providing evidence of a new potential therapeutic target for further investigation.

Objective: This study aimed to assessment the functions of lncRNA WT1-AS in papillary thyroid carcinoma (PTC). Methods: Expression levels of WT1-AS in PTC and non-tumor tissues from 66 PTC patients were measured and compared by performing qPCR and paired t test, respectively. Cell proliferation (CCK-8) assay was performed to evaluate the effects of the overexpression of WT1-AS, miR-203 and survivin on the proliferation of IHH-4 (a human PTC cell line) cells. Results: We found that WT1-AS was significantly downregulated in PTC and associated with clinical stages. In PTC tissues, WT1-AS was negatively correlated with survivin but positively correlated with miR-203. In PTC cells, WT1-AS overexpression led to significantly upregulated miR-203 and downregulated survivin. MiR-203 overexpression failed to affect WT1-AS but downregulated survivin. Cell proliferation assay showed that overexpression of WT1-AS and miR-203 led to decreased, while survivin overexpression led to increased proliferation of PTC cells. In addition, survivin overexpression attenuated the effects of WT1-AS and miR-203 overexpression. Conclusion: Therefore, WT1-AS may downregulate survivin by upregulating miR-203 in PTC to inhibit cancer cell proliferation.