Expression of miR-4695-5p in the serum of colorectal cancer patients and the mechanism of its effect on the proliferation and invasion of colorectal cancer cells / 国际外科学杂志

ABSTRACT

Objective:To explore the expression of microRNA-4695-5p in the serum of colorectal cancer patients and its effect on the proliferation and invasion of colorectal cancer CACO-2 cells.Methods:A total of 43 serum samples of colorectal cancer patients who were admitted to the Department of Gastrointestinal Surgery, Luoyang Central Hospital Affiliated to Zhengzhou University from March 2018 to November 2021 were selected, and serum samples of 43 healthy people who underwent outpatient physical examination were used as controls. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the relative expression levels in the serum of colorectal cancer patients and those of healthy individuals. The miR-4695-5p overexpression plasmid or the negative control plasmid were transfected into CACO-2 cells, namely the miR-4695-5p group and the control group, and the transfection efficiency was verified by qRT-PCR. CCK8 method and Transwell experiment were used to detect the effect of overexpression of miR-4695-5p on the proliferation and invasion of CACO-2 cells. The dual luciferase reporter gene experiment was used to verify the targeted binding relationship between miR-4695-5p and Ras-related C3 botulinum toxin substrate 1 (RAC1). qRT-PCR and Western blot were used to detect the effect of overexpression of miR-4695-5p on the expression of RAC1 gene and Wnt/β-Catenin signaling pathway protein.The software of SPSS28.0 was used to conduct data analysis. The measurement data of normal distribution were espressed by Mean±SD. The t-test was used to compare the means between two groups, and the one-way analysis of variance was used to compare the means of multiple groups. Results:The expression level of miR-4695-5p in the serum of patients with colorectal cancer was significantly lower than that of healthy individuals ( P<0.01). The relative expression levels of miR-4695-5p in the control group and miR-4695-5p group were 1.09 ± 0.65 and 8.83±2.03, respectively. The expression level of miR-4695-5p in CACO-2 cells in the miR-4695-5p group was 8.10 times that of the control group, and CACO-2 cells overexpressing miR-4695-5p were successfully constructed ( P<0.01). Compared with the control group, the proliferation ability of CACO-2 cells in the miR-4695-5p group was significantly reduced ( P<0.05), and the invasion ability of CACO-2 cells was significantly reduced ( P<0.01). Bioinformatics tools and dual luciferase reporter gene experiments confirmed that miR-4695-5p can target and bind RAC1 ( P<0.01). Compared with the control group, the expression of RAC1 gene in the miR-4695-5p group was significantly decreased ( P<0.01), and the expression of Wnt/β-Catenin signaling pathway proteins Wnt3a, β-catenin, and c-MYC decreased significantly. Conclusions:miR-4695-5p is lowly expressed in the serum of colorectal cancer patients. miR-4695-5p inhibits the proliferation and invasion of colorectal cancer CACO-2 cells by targeting the inhibition of RAC1 gene expression and down-regulating the activity of the Wnt/β-Catenin signaling pathway.