不同化疗方案对裸鼠MCF-7乳腺癌移植瘤PCNA和Bcl-2表达的影响

目的：研究不同化疗方案对乳腺癌组织PCNA和Bcl-2的影响，探讨二者与化疗的关系及评价疗效的价值。方法：制备MCF-7乳腺癌荷瘤裸鼠模型，化疗后观察移植瘤病理组织学疗效，用免疫组化SP法显示乳腺癌组织PCNA和Bcl-2表达情况。结果：（1）各化疗组瘤组织PCNA表达显著低于对照组（P〈0．05），且NP、TP和Xeloda组显著低于CMF、CAF组（P〈0．05）。PCNA表达与病理疗效显著相关（P=0．001）。（2）CAF、NP、TP和Xeloda化疗组Bcl-2蛋白表达显著高于对照组（P〈0．05），且TP组显著高于CMF、CAF组（P〈0．05）。Bcl-2表达与病理疗效无显著相关性（P=0．093）。结论：化疗可降低乳腺癌组织PCNA表达，并增强Bcl-2的表达，且不同化疗方案对二者影响的差异有显著性。PCNA可作为评价乳腺癌化疗效果的参考指标，对选择化疗方案可能有指导意义。

The effects of various chemotherapy regimens on the expression of PCNA and Bcl-2 in human breast cancer xenograft (MCF-7) transplanted in nude mice

Objective:To investigate the effects of various chemotherapy regimens on the expression of PCNA and Bcl-2 of breast cancer. To assess relationships between chemotherapy and two markers, and to evaluate the value of them to predict the response of chemotherapy. Methods:Forty-eight nude mice models of human breast cancer xenograft (MCF-7) were established, and then were randomly divided into control and 5 chemotherapy groups (each group, n=8). Among 5 chemotherapy groups, mice were treated intraperitoneallyoral by 5 chemotherapy regimens (CMF, CAF, NP, TP, Xeloda) respectively at two-thirds LD10 (dose lethal to 10% of the mice). Control animals were administered intraperitoneally with normal saline. The pathological feature of transplanted tumor was studied by HE stain, and the expression of Bcl-2 and PCNA was studied by SP immunohistochemical method. Results:(1)The expression of PCNA in 5 chemotherapy group was significantly lower than that of control (P<0.05), and the expression of PCNA in NP, TP and Xeloda groups was significantly lower than that of CMF and CAF groups (P<0.05). Moreover, the expression of PCNA was significantly correlated with pathological therapeutic response(P=0.001). (2)The expression of Bcl-2 in CAF, NP, TP, Xeloda groups was significantly higher than that of control (P<0.05). Moreover, the expression of Bcl-2 in TP group was significantly higher than that of CMF and CAF groups (P<0.05). The expression of Bcl-2 was not significantly correlated with the pathological therapeutic response(P=0.093). Conclusion:Chemotherapy can increase the expression of PCNA, and decrease the expression of Bcl-2. Different chemotherapy regimens have different effects on PCNA and Bcl-2. PCNA can become a factor to evaluate the response to chemotherapy, and become possibly the prospective factor of chemoselect.