A study on expression of miR-145-5p in colorectal cancer and its targeted regulation on GTPBP2 gene

WANG Yongfu; ZHENG Ziheng; XU Chunjin

doi:10.3969/j.issn.1674-3806.2024.05.07

Abstract：Objective To explore the expression of miR-145-5p in colorectal cancer and its regulatory effect on guanosine triphosphate(GTP)-binding protein 2(GTPBP2).Methods The cancer tissues and cancer-adjacent tissues of 44 patients with colorectal cancer who underwent radical resection of colorectal cancer in Shangqiu First People's Hospital,Xinxiang Medical College from January 2022 to December 2022 were selected.Normal human colorectal mucosa cell FHC and colorectal cancer cell HCT116 were selected for basic experiments.Fluorescent quantitative polymerase chain reaction(qPCR)was used to detect the expression levels of miR-145-5p and GTPBP2 mRNA in cancer tissues,cancer-adjacent tissues and the cells.Western blot method was used to detect the expression level of GTPBP2 protein in the cells.Dual luciferase reporter gene assay was used to verify the targeting relationship between miR-145-5p and GTPBP2 gene.The correlation between the expression level of miR-145-5p in colorectal cancer tissues and the clinicopathological features of the patients was analyzed.Results Compared with that in the cancer-adjacent tissues,the expression level of miR-145-5p in cancer tissues was significantly decreased(t=8.189,P＜0.001),and the mRNA expression level of GTPBP2 was significantly increased(t=11.230,P＜0.001).The results of Pearson correlation analysis showed that the expression level of miR-145-5p in colorectal cancer tissues was negatively correlated with the mRNA expression level of GTPBP2(r=-0.503,P＜0.001).The expression level of miR-145-5p was significantly associated with distant metastasis,lymph node metastasis and TNM stage of colorectal cancer(P＜0.05),but was not significantly associated with the patients'gender,age,lesion location,clinical T stage and tumor diameter(P＞0.05).Compared with that in the FHC cells,the expression level of miR-145-5p in the HCT116 cells was significantly decreased(P＜0.001),and the mRNA and protein expression levels of GTPBP2 were significantly increased(P＜0.001).Overexpression of miR-145-5p could down-regulate the expressions of GTPBP2 mRNA and protein in the HCT116 cells.The results of dual luciferase reporter gene assay suggested a targeting relation-ship between miR-145-5p and GTPBP2 gene.Conclusion The expression of miR-145-5p is low in colorectal cancer and miR-145-5p is significantly associated with distant metastasis,lymph node metastasis,and TNM stage and it may affect the occurrence and development of colorectal cancer through targeted regulation of GTPBP2 expression.