ABSTRACT
Objective:To investigate the differences between the expression levels of ribosomal protein L32 (RPL32) in human breast cancer tissue and normal breast tissue and the effects on the proliferation of breast cancer cells.Methods:Paraffin samples of breast cancer tissues and adjacent tissues (more than 3 cm from the tumor margin) were collected from 56 breast cancer patients in the Department of Thyroid and Breast Surgery of the First People's Hospital of Shangqiu City from July 2020 to May 2022. The expression of RPL32 in 56 breast cancer patients and their corresponding paracancer tissues was detected by immunohistochemistry. MCF7 cells were divided into experimental group (ribosomal protein L32, RPL32) and control group (negative control, NC). MCF7 cells in experimental group were transfected with RPL32-siRNA vector, while MCF7 cells in control group were transfected with scramble siRNA vector. RPL32 mRNA content in each group was detected by RT-PCR. The expressions of RPL32 and P53 in the experimental group and control group were detected by western blot. The proliferative ability of cells in each group was detected by CCK8 assay. The clonogenesis ability of each group of cells was detected by clone formation experiment.Results:The positive rate of RPL32 in breast cancer patients was 8.93% (5/56), and the expression rate of RPL32 in paracancer tissues was 78.57% (44/56). The expression rate of RPL32 in breast cancer patients was significantly higher than that in paracancer tissues, with statistical significance ( P=0.007). After transfection with siRNA vector, the mRNA content of RPL32 in MCF7 cells of experimental group and control group decreased, and the protein expression level of RPL32 was 1.09±0.21 and 0.40±0.11, respectively. The expression levels of P53 protein were 1.24±0.32 and 0.37±0.09, respectively. The absorbance of CCK8 at 120 h was 1.11±0.24 and 2.19±0.28, respectively, and the proliferation ability of MCF7 cells in the experimental group was significantly decreased ( P=0.043). The results of clone formation experiment showed that the cell clone formation rate of the experimental group and the control group was (21.11±3.46) % and (58.75±4.29) %, respectively, and the cell clone formation of the experimental group was decreased ( P=0.026) . Conclusions:The expression of RPL32 is significantly increased in breast cancer, which may be related to the malignant degree of breast cancer. Inhibition of RPL32 expression in breast cancer cells affects its proliferation ability.