Transcribed ultraconserved noncoding RNA uc.160 acts as a negative regulator in gastric cancer.

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.