p55PIK N末端24个氨基酸抑制甲状腺癌细胞增殖的研究

目的 观察P55PIK的N端的24个氨基酸抑制甲状腺癌细胞增殖的作用.方法 构建含有P55PIK-N端24个氨基酸的腺病毒载体Ad-N24-p55PIK-GFP及对照病毒Ad-GFP,以其感染甲状腺癌YTC236细胞,流式细胞仪检测细胞周期进程,应用BrdU掺人的方法 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-N24p55PIK-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(69.83±3.50)%,S期和G2/M期细胞数分别为(18.56±3.10)%和(11.61±2.90)%,而带有插入目的 基因的腺病毒Ad-N24p55PIK-GFP感染后的细胞G0/G1期细胞减少为(45.81±2.10)%,S期和G2/M期细胞增加至(30.12±2.60)%和(24.07±2.90)%,BrdU掺入显示BrdU阳性的细胞数由(21.2±3.0)%降至(8.1±2.2)%,FTC236细胞裸鼠移植瘤模型局部应用Ad-N24p55PIK-GFP后肿瘤生长显著减慢.结论 在FTC236细胞中,过表达p55PIK的N末端的24个氨基酸可有效阻滞细胞周期进程,抑制细胞DNA合成,体外有效抑制甲状腺癌裸鼠移植瘤模型的肿瘤生长.

The study of the N-terminal 24 amino acids of the p55PIK Inhibiting the proliferation of thyroid carcinoma cells

Objeetive To elucidate the role of the N-terminal 24 amino acid8 of the p55PIK inhibiting the proliferation of thyroid carcinoma cells.Methods The adenovirus vector Ad-N24p55PIK-GFP containing the N-terminal 24 amino acids of the p55 PIK and the control adenovirus Ad-GFP were constructed,and transfected into the thyroid cancer cell line FTC236.The cell cycle progression was detected by flow cytometer and the DNA synthesis was analyzed by BrdU/PI medthod.By using the nude mice model of FTC236 xenograft tumor.the inhibitory effects of Ad-N24p55PIK-GFP against the tumor were examined.Results In Ad-GFP group,the number of cells in G0/G1 phases was(69.83±3.50)%,and that in the S and G2/M phases was(18.56±3.10)% and(11.61±2.90)% respectively,but in Ad-N24 p55PIK-GFP group,the number of cells in G0/G1 phases was(45.81±2.10)%,and that in the S and G2/M phases cells was(30.12±2.6)% and(24.07±2.90)%respectively.The DNA synthesis was decreased from(21.2±3.0)%in the Ad-GFP group to(8.1±2.2)%in the Ad-N24 p55PIK-GFP group.In the nude mice model of FTC236 xenogratf tumor,after local administration of the Ad-N24p55PIK-GFP,the tumor growth was significantly slowed down.Conclusion In thyroid cancer cell line FTC236.over-expression of the N-terminal 24 amino acid8 of the p55PIK can induce the cell cycle arrest.inhibit the DNA synthesis and suppress the tumor growth in nude mice model of FTC236 xenograft tumor.