LNCRNA UCA1 REGULATING CELL AUTOPHAGY THROUGH AKT/MTOR SIGNAL PATHWAY FOR INHIBITING COLON CANCER CELL PROLIFERATION, PROMOTING CELL APOPTOSIS, AND INCREASING CELL CYCLE ARREST

Fangfang Lin^{1, 2}, Zhangfa Song^{3, *}

¹Medical College of Zhejiang University, Hangzhou 310011, PR China - ²Department of Pathology, Jiangshan People's Hospital, Jiangshan 324100, PR China - ³Department of Anorectal Surgery, Shao Yifu Hospital Affiliated to Zhejiang University Medical College, Hangzhou 310016, PR China

Objective: To analyze long-chain non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) regulating cell autophagy through the protein kinase B/rapamycin target protein (AKT/mTOR) signaling pathway, which inhibits colon cancer cell proliferation and promotes apoptosis and cell cycle arrest. 

Methods: Caco-2 cells were cultured at the same concentration and transfected into si-NC, si-UCA1, and si-UCA1 + 100nmol LRAPA (autophagy inhibitor) groups. Each group was set up with four replicate wells. After 6 h, it was replaced with dual antibodies and the medium of serum to be cultured for 24 h. Cell proliferation was measured using the CCK-8 method in each group. The cell apoptosis and cell cycle changes in each group were detected using flow cytometry, away from light. The expression of microtubule-associated protein light chain 3 (LC3), p62, AKT, and mTOR of cells in each group were determined using Western blotting and PCR. 

Results: The cell proliferation of each group was the same after 24 h. After longer periods of time, the differences in cell proliferation of each group were more obvious. At 72 h, compared with the Si-nc group, the proliferation ability of the si-uca1 and si-uca1 + Rapa group decreased significantly (P < 0.05), and the proliferation ability of the si-uca1 + Rapa group increased significantly (P<0.05). Compared with the Si-nc group, the apoptosis ability of the si-uca1 and si-uca1 + Rapa group was significantly higher (P<0.05), and the apoptosis ability of the si-uca1 + Rapa group was significantly lower than that of the si-uca1 group (P<0.05). In comparison to the Si-nc group, the G1 phase cells in the si-uca1 group were significantly reduced, and the S phase and G phase cells were significantly increased (P<0.05); compared with the si-uca1 group, the G1 phase cells of the si-uca1 + Rapa group were significantly increased, and the S phase and G phase cells were significantly reduced (P<0.05). In comparison to the Si-nc group, the expression level of LC3 and p62 in the Si UCA1 group was significantly lower, and the expression levels of Akt and mTOR were significantly higher (P<0.05)

Conclusion: lncRNA UCA1 may regulate cell autophagy through the AKT/mTOR signaling pathway, thereby inhibiting colon cancer cell proliferation, promoting apoptosis, and blocking the G2 phase of the cell cycle.