Abstract:Objective To detect the expression of the early growth response 1 (EGR1) gene after knocked down the expression of ubiquitin specific protease 7 (USP7) of laryngeal cancer cells, so as to understand the pathogenesis of laryngeal carcinoma. Methods Specific siRNA sequences were designed with lentivirus and the speciality of laryngeal carcinoma HEp-2 cells was transfected to knock down USP7 expression, and then the expressions of immediate early (EGR1) gene from the mRNA and protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Results ①The USP7 mRNA and protein expressions significantly decreased in the knockdown group.② In the knockdown group, RT-PCR revealed increased expression of EGR1 mRNA and Western blot showed elevated expression of EGR1 protein in laryngeal carcinoma cells. ③CCK8 colorimetery revealed that the cell proliferation ability of the knockdown group was significantly lower than those of the negative and blank control groups. Transwell migration assays showed that cell migration ability of the knockdown group was significantly lower than those of the negative and blank control groups. Conclusion Increased expressions of EGR1 at the levels of mRNA and protein after knocking down the USP7 indicates that USP7 may inhibit the expression of EGR1 during the development of laryngeal carcinoma. Therefore, USP7 may play a role in the development of laryngeal cancer by inhibiting the expression of EGR1, providing an experimental evidence for clinical research of laryngeal cancer.