The effect of ΔNp63 knockdown on the growth of pancreatic cancer PANC1 cells

Objective To investigate the effect of deltaNp63(ΔNp63) silencing on the proliferation of pancreatic cancer PANC1 cells. Methods ΔNp63 mRNA level in 23 pairs of pancreatic cancer and adjacent tissue specimen was detected by real-time PCR, and ΔNp63 protein in human normal pancreatic ductal cell line HPDE6-C7 and pancreatic cancer cell line PANC1, CFPAC1 and BXPC3 was detected by Western blot. PANC1 cells were transfectedΔNp63 specific siRNA (ΔNp63-siRNA) and scramble siRNA (Con-siRNA) using liposome, and untransfected cells served as control.ΔNp63 mRNA and protein was detected by real-time PCR and Western blot to validate the silencing ofΔNp63 expression. MTT assay and BrdU method were used to detect the proliferation and DNA synthesis of transfected PANC1 cells. Results The ΔNp63 mRNA expression in pancreatic cancer tissues and matched adjacent normal tissues was 0.99± 0.07and 0.70±0.07, respectively. ΔNp63 mRNA expression in pancreatic cancer tissue was significantly up-regulated compared with that in the normal tissue (P=0.0034). The ΔNp63 protein expression in HPDE6-C7, PANC1, CFPAC-1 and BxPC3 cells was 0.97±0.09, 3.06±0.16, 2.57±0.11 and2.45±0.08, respectively. TheΔNp63 protein level in pancreatic cancer cells were higher than that in HPDE6-C7 cells (P<0.001). ΔNp63 mRNA level in control, Con-siRNA and ΔNp63-siRNA group was 0.97±0.07, 0.97±0.07 and0.28±0.03, respectively, and ΔNp63 protein expression level was 0.97±0.06, 1.00±0.10 and 0.26±0.03. The expression of ΔNp63 mRNA and protein inΔNp63-siRNA group were significantly down-regulated comparing with those in Con-siRNA group (P<0.01). Significant inhibition on cell proliferation was observed in ΔNp63-siRNA group, which was statistically different from that in control and Con-siRNA group. The A490 value (DNA synthesis) of control, Con-siRNA and ΔNp63-siRNA group was 0.55±0.04, 0.56±0.01 and 0.55±0.00 at 24 h after transfection, and 0.84±0.05, 0.87±0.07 and0.71±0.05 at 48 h after transfection. The DNA synthesis in ΔNp63-siRNA group was significantly down-regulated compared with that in control and Con-siRNA group (P<0.05). Conclusions Knockdown of ΔNp63 could greatly inhibit the proliferation and DNA synthesis of pancreatic cancer PANC1 cells. Key words: Pancreatic neoplasms; Gene silencing; Genes, p53; Cell prdiferation