结直肠癌中Kras 基因表达与放射治疗的研究进展

结直肠癌(Colorectal cancer，CＲC)是由抑癌基因和致癌基因的突变积累导致。Kras 是原癌基因作
用于表皮生长因子(Vascular endothelial growth factor，EGFＲ)的下游，通过小鼠肉瘤病毒癌基因同源基因B 1(vraf
murine sarcoma viral oncogene homolog B1，BＲAF) 传递信号，触发促分裂原活化的蛋白激酶(mitogenactivated
protein kinase，MAPK)通路，诱导细胞增殖，阻止细胞凋亡，引起了55% ～ 60%的CＲC．因此，Kras 基因的突变与
CＲC 的发生、发展、预后、及其药物治疗与放射治疗有着密不可分的联系，本文对CＲC 中Kras 基因表达与放射治
疗的研究进展进行系统的综述。     

A modular and flexible ESC-based mouse model of pancreatic cancer

Genetically engineered mouse models (GEMMs) have greatly expanded our knowledge of pancreatic ductal adenocarcinoma (PDAC) and serve as a critical tool to identify and evaluate new treatment strategies. However, the cost and time required to generate conventional pancreatic cancer GEMMs limits their use for investigating novel genetic interactions in tumor development and maintenance. To address this problem, we developed flexible embryonic stem cell (ESC)-based GEMMs that facilitate the rapid generation of genetically defined multiallelic chimeric mice without further strain intercrossing. The ESCs harbor a latent Kras mutant (a nearly ubiquitous feature of pancreatic cancer), a homing cassette, and other genetic elements needed for rapid insertion and conditional expression of tetracycline-controlled transgenes, including fluorescence-coupled shRNAs capable of efficiently silencing gene function by RNAi. This system produces a disease that recapitulates the progression of pancreatic cancer in human patients and enables the study and visualization of the impact of gene perturbation at any stage of pancreas cancer progression. We describe the use of this approach to dissect temporal roles for the tumor suppressor Pten and the oncogene c-Myc in pancreatic cancer development and maintenance.     

非小细胞肺癌中Kras与Braf蛋白的表达及其意义

[目的]明确Kra和Braf蛋白在非小细胞肺癌的表达状况,并探讨其临床意义.[方法]应用免疫组织化学SP法检测126例手术切除非小细胞肺癌组织和其中26例癌旁组织的Kras和Braf蛋白表达情况.分析Kras和Braf蛋白的表达与临床病理学参数之间的关系.[结果]Kras蛋白阳性表达率在肺癌组与癌旁组之间的差异无显著性...