【摘要】 目的 :通过检测直肠癌术前放疗患者放疗前后凋亡、增殖指数以及凋亡调控基因表达的变化 ,探讨直肠癌自发性凋亡及放射性凋亡的可能调控机制。方法 :分析 2 3例接受术前放疗的直肠癌患者的临床资料。采用TUNEL法观察放疗前活检标本及放疗后手术切除标本的细胞凋亡情况。免疫组化方法检测所取标本的p5 3、p2 1、PCNA、bcl 2、bax等表达情况。结果 :放疗前活检标本中凋亡指数为 2 8± 1 4,而放疗后标本中凋亡指数为 4 9± 1 3 ,P <0 0 1。放疗后p5 3、p2 1、bcl 2、PCNA染色阳性率较放疗前均下降 ,而bax表达阳性率由放疗前的 3 4 8%上升到放疗后的 65 2 % ,但差异均无统计学意义 ,P >0 0 5。在放疗前活检标本中 ,p5 3 ( -)p2 1( +)组的凋亡指数为 4 2± 1 0 ,高于p5 3 ( +)p2 1( -)组的 2 3± 0 6,P <0 0 5。放疗后手术标本中 ,p5 3 ( -)p2 1( +)组的凋亡指数为 5 8± 1 5 ,高于p5 3 ( +)p2 1( -)组的 4 3±0 6,P <0 0 5。结论 :在直肠癌组织的自发凋亡和放射性凋亡过程中 ,p5 3 /p2 1途径均起到了关键作用 ,bax也可能起到一定的作用。更多还原

【Abstract】 OBJECTIVE:To investigate the relationship between apoptotic cell death and the expression of apoptosis regulating proteins in rectal cancer tissues prior to and after pre-operative radiotherapy,and probe into the possible mechanism of spontaneous apoptosis and radiation induced apoptosis in rectal carcinoma.METHODS: In 23 patients received preoperative radiotherapy for locally advanced rectal carcinoma, pretherapy biopsies and the final resected specimen of the cases were available for analyses. Immunohistochemistry for proliferating cell nuclear antigen, p53, p21, bcl-2, bax was performed. Pre- and post- operative apoptosis indexes were examined by TUNEL method.RESULTS: After radiotherapy, the apoptotic index increased significantly from 2.8±1.4 to 4.9±1.3, P<0.01. In pre-radiotherapy biopsy specimen,tumors that were p53(-)p21(+) were more likely to exhibited higher rate of apoptosis (4.2±1.0) than that of p53(+)p21(-)(2.3±0.6), P<0.05. In post-therapy resected specimen, tumors that were p53(-)p21(+) were more likely to exhibited higher rate of apoptosis (5.8±1.5) than that of p53(+)p21(-)(4.3±0.6),P<0.05.CONCLUSIONS: The p53/p21 path and bax might be possible regulating factors of spontaneous or radiation-induced apoptosis in rectal carcinoma.更多还原