Objective To summarize the current advancement of preoperative radiotherapy for rectal cancer. Methods Relevant literatures about current advancement of preoperative radiotherapy for rectal cancer published domesticly and abroad recently were collected and reviewed. Results The lower local recurrence rate and longer disease-free survival time were observed in preoperative radiotherapy， compared with postoperative radiotherapy for rectal cancer. The recurrence rate was higher in short-course radiotherapy， compared with conventionally radiotherapy for stageⅢrectal cancer， but there was no significant difference for stageⅡrectal cancer. The biology molecular such as p53， CEA， Cox-2， EGFR， and VEGF had shown to be radiosensitive. Conclusions The proposal of preoperative radiotherapy for rectal cancer， could be prone to conventionally radiotherapy. There are more screening targets for preoperative radiotherapy in extensive exploration of diverse radiosensitivity. Biology molecular， developed gene expression profiling， and gene chips for rectal cancer may contribute to the individualization treatment.
目的:探讨人凋亡相关新基因PNAS-4(hPNAS-4)基因通过脂质体转染至Lewis肺癌LL2细胞后对放射治疗的增敏作用。〖HTH〗方法〖HTSS〗:用脂质体介导的转染技术,将hPNAS-4基因导入Lewis肺癌LL2细胞中,Western blot鉴定其过表达后,观察X射线照射对其集落形成的影响;流式细胞仪检测hPNAS-4基因或／和放疗(0,1,2,4,6 Gy)对LL2细胞生长抑制及凋亡的影响。〖HTH〗结果〖HTSS〗:通过Western blot证实了hPNAS-4基因在LL2细胞中的过表达。Lip-hPNAS-4加放射治疗处理组细胞的生存能力明显降低,肿瘤细胞的克隆形成明显减少,流式细胞术检测体外培养的肿瘤细胞凋亡明显增加。〖HTH〗结论〖HTSS〗:hPNAS-4基因联合放射治疗能产生协同抗肿瘤效应。