Hsa_circ_0001696 modulates cell proliferation and migration in colorectal cancer.

Circular RNAs (circRNAs) are a novel class of endogenous non-coding RNA molecules that are extensively expressed in a variety of species. Recently, increasing evidence suggests that circRNAs have vital functions indifferent types of human cancer, such as gastric cancer, papillary thyroid cancer and lung cancer. However, the roles of circRNAs in the development of colorectal cancer (CRC) remain unclear. The present study aimed to determine the molecular mechanism underlying hsa_circ_0001696 on the proliferation and migration of CRC cells. Reverse transcription-quantitative PCR analysis was performed to detect hsa_circ_0001696 expression in 18 paired CRC tissues and matched adjacent normal tissues. RNA interference was also performed to decrease hsa_circ_0001696 expression, and its biological effects were further assessed via flow cytometry, wound healing, colony formation and western blot assays. The results demonstrated that hsa_circ_0001696 expression was significantly lower in CRC tissues compared with adjacent normal tissues. Furthermore, hsa_circ_0001696 knockdown promoted cell proliferation and migration, and the number of cell colonies significantly increased. In addition, western blot analysis demonstrated that the protein expression levels of cyclin-dependent kinase 4 (CDK4), cyclin D, cyclin E and matrix metalloproteinase 9 (MMP9) increased. Taken together, the results of the present study demonstrated that hsa_circ_0001696 expression was downregulated in CRC tissues, and inhibition of hsa_circ_0001696 promoted cell proliferation and migration by regulating the levels of CDK4, cyclin D, cyclin E and MMP9.