Abstract：Objective To evaluate the effect of down-regulation of RACK1 expression on growth and radiosensitivity of oral squamous cell carcinoma cells. Methods The shRNA vector for RACK1 gene was constructed and transfected into HSC-3 cells by lipofectamine. The stably-transfected cell line was obtained by constructing G418. The expression levels of RACK1 mRNA and protein were detected by RT-PCR and Western blot. The cell proliferation was detected by CCK8 assay. Cell apoptosis was examined by flow cytometry. The invasive and metastatic capabilities of cancer cells were assessed by cell invasion assay in vitro.The effect of X-ray irradiation combined with down-regulation of RACK1 expression upon cell proliferation was assessed by clone formation assay. The xenograft tumor nude mouse model was established to observe the inhibitory effect of down-regulating RACK1 gene expression combined with X-ray irradiation on oral squamous cell carcinoma. Results RT-PCR revealed that the expression level of RACK1 mRNA of transfected HSC-3 cells was significantly down-regulated (P<0.05). Western blot showed that the expression level of RACK1 protein was significantly down-regulated (P<0.05). CCK8 assay demonstrated that down-regulation of RACK1 expression could remarkably inhibit the growth of HSC-3 cells (P<0.05). RACK1 gene shRNA interference combined with X-ray irradiation significantly enhanced the apoptosis rate of HSC-3 cells (P<0.05). The number of invasion cells in vitro in the RACK1 silencing group was evidently decreased (P<0.05). Clone formation assay showed that the survival fraction in the shRACK1 group was significantly lower than that in the control group. The sensitization enhancement ratio was 1.37(ratio of D0 value). Xenograft tumor experiment in nude mice showed that tumor growth was significantly inhibited in the shRACK1 group, the tumor volume was significantly decreased and the tumor mass was significantly lower than those in the control group (all P<0.05). Conclusion Down-regulating RACK1 expression can enhance the radiosensitivity of oral squamous cell carcinoma cells, providing novel thinking to improve the radiosensitivity of oral squamous cell carcinoma.
Liu Dongmei,Liu Xinju,Wang Wen et al. Study of effect of silencing RACK1 expression by shRNA on enhancing radiosensitivity of oral squamous cell carcinoma cells[J]. Chinese Journal of Radiation Oncology, 2021, 30(4): 397-402.
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