不同方法检测K-Ras基因突变与转移性结直肠癌疗效及预后的关系

Correlation between K-Ras mutations in different detections and prognosis of colorectal cancer

目的探讨直接测序法和肽核酸钳制PCR(PNA-PCR)法检测K-Ras基因突变状态与转移性结直肠癌患者疗效及预后的相关性。方法收集110例转移性结直肠癌患者的石蜡包埋肿瘤组织,采用直接测序法和PNA-PCR法分别检测肿瘤组织的K-Ras基因第2外显子第12、13密码子的突变状态,并分析其与患者预后的关系。结果直接测序法检测到43例K-Ras基因突变,PNA-PCR法除了检测出这些突变之外,还在直接测序法检测的野生型中发现了10例突变。对K-Ras突变状态与患者的预后分析发现,直接测序法检测的K-Ras野生型及突变型患者的中位生存时间(OS)分别为20.5个月和15.6个月(P=0.067)。PNA-PCR法检测的野生型和突变型患者的中位OS分别为21.3个月和15.8个月(P=0.014)。两种方法检测的野生型与突变型的有效率和无病进展时间(PFS)差异均无统计学意义。按照这两种方法的检测结果分为3组,高突变组、低突变组和野生型组,仅高突变组与野生型组的OS差异有统计学意义(15.6个月vs.21.3个月,P=0.040)。Cox多因素分析显示,ECOG评分(HR=2.70,95%CI:1.39～5.25,P=0.003)和K-Ras丰度(HR=1.52,95%CI:1.52～2.19,P=0.026)与患者的预后相关。结论 K-Ras突变不是以伊立替康或奥沙利铂为主方案的疗效预测因子。PNA-PCR法检测的K-Ras突变状态与患者的预后有关。建议用PNA-PCR法确定野生型患者,而突变型患者则用直接测序法来确定。

Objective To investigate the possible signal pathway of multi-drug resistant P-glycoprotein（P-gp）expression induced by cyclooxygenase-2（COX-2）in hunman gastric adenocarcinoma cell line SGC-7901 stimulating with pacliaxel（TAX）.Methods The effects of TAX on SGC-7901 cells growth was assessed by MTT assay,and so did the effects of COX-2 selective inhibitor NS-398 and nuclear factor-κB（NF-κB） pathway inhibitor pyrrolidine dithiocarbamate（PDTC）.The effect of a dose-ranging TAX and the change of combining NS-398 or PDTC with TAX on the COX-2,p65 and P-gp expression were detected by Western blotting.Results TAX,NS-398 and PDTC all had the effect of cellular toxicity on SGC-7901 cell line growth in a dose-dependent manner.When the dose of TAX（0.1,0.3,0.5μmol/L） increased,the expression of COX-2,p65 and P-gp showed rising trend in SGC-7901 cell line.And the expression of three proteins could decrease with the increase of dose and extension of time after combined with NS-398（5,10μmol/L）.When combined with PDTC（0.2μmol/L）,the expression of p65 and P-gp decreased significantly.Conclusion COX-2 may induce the expression of P-gp in SGC-7901 cell line via NF-κB pathway with the stimulation of TAX.