磷脂酰肌醇-3激酶p55γ-N末端24个氨基酸抑制结肠癌细胞增殖的作用  

Inhibitory Effect of N-Terminal 24 Amino Acids of the p55 Gamma,a Regulatory Subunit of Phosphoinositide 3-Kinase,on Proliferation of Colon Carcinoma Cell Line HT29

作　　者：王桂华[1] 罗学来[1] 孙黎[2] 邓豫[1] 李小兰[1] 陶德定[1] 胡俊波[1] 龚建平[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院分子医学中心,湖北武汉430030 [2]华中科技大学同济医学院第二临床学院,湖北武汉430030

出　　处：《癌症》2008年第10期1034-1038,共5页Chinese Journal of Cancer

基　　金：国家自然科学基金(No.30300338);国家973项目(No.2002CB513100-2)~~

摘　　要：背景与目的:p55γ是磷脂酰肌醇3激酶(phosphoinositide 3-kinase,PI3K)的调节亚单位之一,在调节PI3K活性上具有重要的作用。本研究旨在观察PI3K的一个调节亚基p55γ-N末端24个氨基酸抑制结肠癌细胞增殖的作用。方法:构建含有PI3K-p55γ-N末端24个氨基酸的腺病毒载体Ad-N24p55-GFP及对照病毒Ad-GFP,以其感染结肠癌HT29细胞,流式细胞仪检测细胞周期进程,应用BrdU掺入法检测其对细胞DNA合成的影响,通过建立体内肿瘤裸鼠移植瘤模型进一步证实Ad-N24p55-GFP的抗肿瘤作用。结果:对照腺病毒Ad-GFP感染的细胞中G0/G1期细胞为65.11%,S期和G2/M期细胞数分别为17.37%和17.51%;而带有插入目的基因的腺病毒Ad-N24p55-GFP感染后的细胞G0/G1期细胞增至73.39%,S期和G2/M期细胞减少至15.08%和11.13%。BrdU掺入法结果显示BrdU阳性的细胞数由24.82%降至9.27%(P<0.05)。HT29细胞裸鼠移植瘤模型局部应用Ad-N24p55-GFP后肿瘤生长显著减慢,其瘤重明显低于空白对照组和腺病毒对照组[(0.32±0.08)gvs.(0.67±0.30)g,(0.72±0.28)g,P<0.05]。结论:过表达PI3K-p55γ-N末端24个氨基酸可有效阻滞HT29细胞周期进程,抑制细胞DNA合成;并可有效抑制结肠癌裸鼠移植瘤模型的肿瘤生长。BACKGROUND ＆ OBJECTIVE= p55 gamma is one of the regulatory subunits of phosphoinositide 3-kinase （PI3K）, which plays an important role in the regulation of PI3K activity. This study was to explore the inhibitory effect of the N-terminal 24 amino acids of the p55 gamma on proliferation of colon carcinoma cell line HT29. METHODS. Ad-N24p55-GFP, containing N-terminal 24 amino acids of the p55 gamma, and control vector Ad-GFP were constructed, and used to infect HT29 cells. The cell cycle progression was detected using flow cytometry. DNA synthesis was analyzed using the BrdU/PI method. The nude mice model bearing HT29 xenograft tumors was used to study the effect of Ad-N24p55-GFP against the tumor. RESULTS.. Compared with cells infected with Ad-GFP, cells infected with Ad- N24p55-GFP at the G0/G1 phase were increased from 65.11% to 73.39% P〈 0.05, and cells at S and G2/M phases were decreased from 17.37% to 15.08% and from 17.51% to 11.13%, respectively; BrdU-positive cells were decreased from 24.82% to 9.27%. In the nude mice model, the tumor growth was inhibited after the administration of Ad-N24p55-GFP. The tumor weight was （0.32±0.08）g vs. （10.67±0.3）g and （0.72±0.28）g in the Ad-N24P55-GFP group,the blank control group and the Ad-GFP group, respectively, CONCLUSION= In HT29 cells, overexpression of the N-terminal 24 amino acids of the p55 gamma can induce cell cycle arrest, inhibit DNA synthesis and inhibit tumor growth in the nude mice model of HT29 xenograft tumors.

关 键 词：结肠肿瘤 HT29细胞 腺病毒 BrdU掺入 磷脂酰肌醇-3激酶 细胞周期 DNA合成 

分 类 号：R735.35[医药卫生—肿瘤]