Objective: This study aimed to investigate the role of protein kinase D (PKD)1 in regulating the growth, apop-tosis, and drug sensitivity of the squamous carcinoma cell line SCC-25.
Methods: The SCC-25 cell line was transfected with either the control-shRNA or PKD1-shRNA plasmids. The stable transfected cells were selected, and the efficiency of PKD1 knockdown was detected by Western blot. The growth and apoptosis of SCC-25 were analyzed with a cell counting kit-8 (CCK8) and flow cytometry. The 50% inhibitory concentrations (IC50) of paclitaxel in the control and PKD1 knockdown cell lines were detected by CCK-8. The expression levels of Bax, Bcl-2, and P-gp were detected by Western blot.
Results: PKD1 was constitutively expressed and phosphorylated in various cancer cell lines. Inhibiting the expression of PKD1 in SCC-25 cells by RNA interference could inhibit the growth and promote the apoptosis of SCC-25 cells via downregulating Bcl-2 expression. Additionally, inhibiting PKD1 expression could downregulate the expression of P-gp, thereby decreasing both the IC50 and resistance index of paclitaxel.
Conclusions: PKD1 plays an important role in regulating the biobehavior of SCC-25. It is a potential therapeutic target for oral squamous carcinoma.
目的 探讨蛋白激酶D1（PKD1）在人口腔鳞癌细胞SCC-25生长、凋亡及化疗药物敏感性中的作用和机制。方法 转染control-shRNA和PKD1-shRNA质粒，建立PKD1基因沉默的SCC-25细胞系；CCK-8及流式细胞术检测PKD1基因沉默后细胞的增殖、凋亡及细胞对化疗药物紫杉醇的敏感性；Western blot检测凋亡相关蛋白Bax、Bcl-2及多药耐药蛋白P-gp的表达变化。结果 PKD1在口腔肿瘤细胞SCC-25、CAL-27、SACC-83中呈现高表达；PKD1基因沉默后SCC-25细胞内抗凋亡蛋白Bcl-2表达显著降低，细胞生长受到抑制，凋亡增加；多药耐药蛋白P-gp表达下调，紫杉醇半数抑制浓度及耐药指数明显降低。结论 PKD1通过调控SCC-25细胞内凋亡相关蛋白表达和多药耐药蛋白P-gp表达，调控SCC-25生长、凋亡和对药物敏感性，是口腔鳞癌细胞生物治疗潜在靶点。.
Keywords: multi-drug resistance; oral squamous carcinoma; paclitaxel; protein kinases D1.