Circular RNA hsa_circ_102209 promotes the growth and metastasis of colorectal cancer through miR-761-mediated Ras and Rab interactor 1 signaling
Abstract Background: In our study, has_circ_102209 was the most upregulated gene in colorectal cancer (CRC) tissues according to circRNA array data. The levels of hsa_circ_102209 in CRC specimens and cells, as well as its effects on CRC cells were investigated. Methods: The expression of hsa_circ_102209 in CRC and paired non-cancerous samples, human CRC and normal colonic epithelial cells were examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cells with hsa_circ_102209 knockdown were established using lentiviral vectors . Cell proliferative ability was evaluated using CCK-8 assay; cell migration and invasion were assessed by wound healing and Transwell assay. Cell cycle arrest and apoptosis were determined; apoptosis and EMT markers were examined using RT-qPCR and western blotting. Tumour development and levels of associated proteins were determined in hsa_circ_102209 knockdown mice. Results: Our results revealed that expression of hsa_circ_102209 was remarkably increased in CRC tissues, where the levels of miR-761 were notably reduced (p<0.05). Additionally, the levels of hsa_circ_102209 was associated with tumor stage and occurrence of liver metastasis in CRC patients, and the expression of hsa_circ_102209 and miR-761 were negatively correlated (p<0.05). Moreover, hsa_circ_102209 was upregulated in CRC cell s compared with normal colonic epithelial cells. Knockdown of hsa_circ_102209 notably inhibited the proliferation, migration, invasion and EMT of CRC cell s (p<0.05), whereas enhanced cell cycle arrest at G0/G1 phase and apoptosis (p<0.05). Furthermore, miR-761/ Ras and Rab interactor 1 ( RIN1) axis was the putative target of hsa_circ_102209 in CRC and involved in hsa_circ_102209 -modulated growth and metastasis in CRC cell s (p<0.05). Knockdown of hsa_circ_102209 also remarkably suppressed tumor growth in vivo (p<0.05). Conclusions: our data revealed that the expression of hsa_circ_102209 was elevated in CRC samples and cells. Furthermore, hsa_circ_102209 could promote the progression of CRC through miR-761/RIN1 axis. More importantly, hsa_circ_102209 /miR-761/RIN1 signaling may be a novel therapeutic target for the treatment of CRC patients .