Background: Transcribed ultraconserved regions (T-UCRs) are a subset of long noncoding RNAs. It has been reported that T-UCRs are dysregulated in cancers and play an important role in the development and progression of malignancies. uc.160 was found to be a suppressive factor of cancer development, but its role has not been fully elucidated.
Methods: The uc.160 expression was examined in gastric cancer tissues and established cell lines by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The biological function of gastric cancer cells with uc.160 over-expression were investigated, and the interaction between uc.160 and microRNA miR-155 was examined by dual-luciferase reporter assay. PTEN levels were detected by Western blotting. Anti-tumor effects of uc.160 were further explored in tumor transplantation models.
Results: uc.160 expression was significantly down-regulated in gastric cancer tissues and gastric cell lines as compared to adjacent normal tissues and immortalized gastric epithelial cell line (GES-1), respectively. Over-expression of uc.160 in SGC-7901 and AGS gastric cancer cells significantly suppressed their proliferation in vitro and in vivo. Moreover, uc.160 positively regulated the tumor suppressor protein PTEN. Interestingly, uc.160 was inhibited by microRNA miR-155 that is also a negative regulator of gastric cancer.
Conclusion: uc.160 is significantly down-regulated in gastric carcinomas and can inhibit the tumor growth both in vitro and in vivo, suggesting that uc.160 may be used as a diagnostic marker and therapeutic target of gastric malignancies.
Keywords: Noncoding RNA; tumor suppressor; uc.160.