Role of protein kinase D1 in regulating the growth, apoptosis and drug sensitivity of oral squamous carcinoma cells / 华西口腔医学杂志

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.

Effect of Paclitaxel on Expression of PD-L1 in Surface of Cervical Cancer TC-1 Cells / 医药导报

Objective To investigate effect of paclitaxel on expression of programmed death ligand-1 ( PD-L1 ) in the surface of cervical cancer TC-1 cells and its mechanism. Methods ①The cells were divided into two groups: paclitaxel group, paclitaxel combined with PKD blocker (G? 6976) group. There were 4 concentration gradient and 5 holes for each group, and each hole has its corresponding concentration of drugs. Influence of paclitaxel on TC-1 cell viability and effect of PKD blocker G? 6976 on IC50 value of paclitaxel were evaluated by MTT method.②The cells were divided into 0. 9% sodium chloride solution ( NS) group and paclitaxel group, There were 5 holes of each group. Effect of paclitaxel on PD-L1 expression on the surface of TC-1 cells were measured by immunohistochemistry.③The cells were divided into 4 groups:NS+DMSO group, G? 6976 group, paclitaxel group and paclitaxel+G? 6976 group. There were 5 holes for each group. Effect of paclitaxel and G? 6976 on PD-L1 expression on the surface of TC-1 cells were measured by immunohistochemistry. The expressions of PD-L1 on the surface of cells were measured by immunofluorescence treated with different drugs. Results The IC50 value of paclitaxel was 40 μg·mL-1 in paclitaxel group, and 38. 9 μg·mL-1 in paclitaxel combined with PKD blocker G? 6976 group, without significant difference between the two groups (P>0. 05). The expression of PD-L1 in the surface of TC-1 cells were significantly higher in paclitaxel group than in negative control group [(88. 48±13. 44)% vs. (39. 59±5. 99)%, P<0. 05]. The expression of PD-L1 in the surface of TC-1 cells was (79. 7%±4. 7)% after treatment with paclitaxel combined with PKD blocker G? 6976 for 24 h, and it was significantly lower than that in paclitaxel group [(96. 8±2. 5)%, P<0. 05]. Conclusion Paclitaxel promotes the expression of PD-L1 in the surface of TC-1 cells, which could be significantly inhibited by blocking PKD pathway. Paclitaxel may exert its effect through PKD pathway.