吉西他滨与埃罗替尼联用对人胰腺癌细胞生长的影响

Effects of gemcitabine plus erlotinib on the proliferation of pancreatic cancer cells

目的探讨吉西他滨与埃罗替尼不同用药次序联合应用对人胰腺癌细胞BXPC-3及PANC-1生长的影响及其可能的机制。方法RT-PCR法和Western blotting法分别检测表皮生长因子受体(EGFR)mRNA及蛋白表达。MTT法检测吉西他滨(3×10-11～3×10-2mol/L)与埃罗替尼(10-8～10-4mol/L)单药对细胞生长的影响,并计算IC50浓度;观察吉西他滨(IC50浓度)与埃罗替尼(10-5mol/L)单药、同时或续贯应用(间隔24h或72h)对细胞生长的影响。流式细胞术检测细胞周期。结果BXPC-3及PANC-1细胞内均有EGFRmRNA及蛋白表达。吉西他滨(3×10-10～3×10-2mol/L)和埃罗替尼(10-6～10-4mol/L)呈时间和浓度依赖性地抑制细胞生长。两药联用对细胞的影响与给药次序有关:与单药组比较,同时给埃罗替尼和吉西他滨(P=0.034,P=0.049)或先用埃罗替尼后用吉西他滨(P=0.001,P=0.025)对2种细胞的抑制作用显著增强;先用吉西他滨后用埃罗替尼对细胞的抑制作用与单用吉西他滨相比无明显变化(P=0.499,P=0.824);同时给予埃罗替尼和吉西他滨与先用埃罗替尼后用吉西他滨相比对细胞的抑制作用无显著差异(P=0.199,P=0.767)。各用药组均将BXPC-3细胞周期阻断在G1期。结论吉西他滨与埃罗替尼均能抑制人胰腺癌细胞的生长,两者联合同时给药或先用埃罗替尼后用吉西他滨的作用强于吉西他滨单独用药,这种作用与药物对细胞周期的影响无关。

Objective To investigate the sequence-dependent effects of gemcitabine plus erlotinib on the proliferation of human pancreatic carcinoma cells, BXPC-3 and PANC-1, and the possible mechanisms involved. Methods The expressions of mRNA and protein of endothelial growth factor receptor （EGFR） were determined by RT-PCR and Western blotting respectively. MTT assay was used to examine the effects of gemeitabine （3 × 10^-11 -3 × 10^-2mol/L） and erlotinib （ 10 ^-8 - 10^ -4 mol/L）, respectively, on the proliferation of human pancreatic carcinoma cells, then the IC50 was calculated subsequently. The effects of gemcitabine （IC50） and erlotinib （10 s mol/L） either administered alone, simultaneously, or sequentially （with 72h or 24h interval） on the proliferation of cells with MTT assay. Cell cycle was detected by flow cytometry. Results Both mRNA and protein of EGFR were expressed in BXPC 3 and PANC 1 cells. Gemcitabine （3 × 10^-10-3 × 10^-2mol/L） and erlotinib （10 ^-4- 10^-4 mol/L） significantly inhibited the proliferation of BXPC-3 and PANC-1 ceils in a timeand concentration-dependent manner. The effects of gemcitabine plus erlotinib on cell proliferation were sequence-dependent. The inhibitory effects on cell proliferation was enhanced when administered simultaneously （P= 0. 034; P= 0. 049） or erlotinib was administered 24h prior to gemcitabine （P=0. 001; P=0. 025） in comparison to that of each drug used alone. However, administration of erlotinib 24h after that of gemcitabine （P=0. 499, P=0. 824） exerted no additive effects on the cell proliferation when compared with the effect of gemcitabine used alone. No statistical difference existed in the inhibitory effects on cell proliferation between the simultaneous administration of both drugs and the gemcitabine administration following erlotinib （P=0. 199, P=0. 767）. Erlotinib plus/or gemcitabine treatment resulted in the block of cell cycle of BXPC-3 cells at G1 phase. Conclusions Both gemcitabine and erlotinib can inhibit the proliferation of BXPC-3 and PANC-1 cells. The concurrent administration or sequential administration of gemcitabine following erlotinib exerts stronger additive effects on cell proliferation than when gemcitabine is used alone. However, the additive effects are not related to the influence of the both drugs on cell cycles.