ZHANG Zhiyong,QIU Feng. The expression of long non-coding RNA Linc00658 in colorectal cancer and its relationship with cetuximab resistance[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2020, 50(11): 890-895.
Abstract：Objective: To investigate the expression of long non-coding RNA (lncRNA) Linc00658 in colorectal cancer (CRC) and its relationship with cetuximab resistance. Methods: Bioinformatics was used to predict the lncRNA which are closely related to the expression of miR-19a-3p and PTEN. CaCo2 cells were treated with cetuximab and DMSO as the resistance group and the control group, and overexpressing Linc00658 was used as the overexpression group in resistance group. miR-19a-3p mimic and NC transfected into CaCo2 cells were respectively as mimic group and NC group. The expression levels of Linc00658, miR-19a-3p and PTEN mRNA were detected by real-time fluorescent quantitative PCR (qRT-PCR) in the control, resistance, overexpression group. The expression of PTEN and its downstream genes phosphorylated Akt (p-Akt) and phosphorylated mTOR (p-mTOR) were detected by Western blot. The 50% inhibitory concentration (IC50) of cetuximab was detected by CCK-8 assay, and the binding of Linc00658 and miR-19a-3p and its effect on the binding of miR-19a-3p and PTEN were verified by dual luciferase reporter gene. Results: Compared with the control group, the expression of Linc00658, PTEN mRNA and protein decreased significantly in the resistant group, the expression of miR-19a-3p, p-Akt and p-mTOR increased significantly, and the IC50 of cetuximab enhanced significantly(P<0.01). Compared with the resistant group, the expression of Linc00658, PTEN increased significantly in the overexpression group, and the expression of miR-19a-3p, p-Akt, p-mTOR and cetuximab IC50 decrease dsignificantly(P<0.05). Compared with NC group, IC50 of cetuximab in mimic group was significantly higher(P<0.01). miR-19a-3p mimic could significantly inhibit luciferase activity of pGL3-basic-Linc00658, suggesting that miR-19a-3p and linc00658 had binding effect. Overexpression of Linc00658 could restore the fluorescence inhibition mediated by miR-19a-3p mimic on pGL3-basic-PTEN. Conclusion: Linc00658 could promote PTEN re-expression and sensitivity to cetuximab of CRC cells by sorption of miR-19a-3p.
