肽核酸对大肠癌LS-174T细胞生长抑制作用

Inhibitory effect of peptide nucleic acid on the growth of colorectal cancer LS-174T cells

目的:探讨肽核酸(peptideorpolyamidenucleicacid,PNA)对大肠癌细胞端粒酶活性的抑制作用及对大肠癌细胞生长的影响.方法:应用脂质体LipfectamineTM介导不同浓度(25,50,100,200,400nmol/L)PNA-DNA杂交混合物转染LS-174T细胞,通过细胞克隆生长抑制试验来测定PNA对细胞生长的最佳抑制剂量;选用最佳抑制剂量PNA转染LS-174T细胞,同时设置脂质体组(LipfectamineTM)组和空白对照组,观察克隆形成率、细胞形态及群体生长差异.结果:PNA对LS-174T细胞最佳抑制浓度为200nmol/L.PNA实验组端粒酶活性和克隆形成率明显低于脂质体组和空白对照组(0.003±0.001vs2.334±0.025,2.528±0.032,P<0.01;5.20%vs45.45%,47.13%,P<0.01).PNA组癌细胞生长出现典型形态学改变,细胞变圆、胞膜皱缩、细胞核边集于核膜,通过群体生长曲线,转染后11d出现抑制作用,15、17d抑制作用最显著.结论:体外试验中PNA对大肠癌LS-174T细胞生长有明显的抑制作用,其作用机制可能是PNA对大肠癌细胞端粒酶活性的抑制.

AIM： To explore the inhibitory effect of peptide nucleic acid （PNA） on the telomerase activity and the growth of colorectal cancer cells. METHODS： LS-174T cells were transfected with the mixture of PNA-DNA at different concentrations （25, 50, 100, 200, 400 nmol/L） mediated by LipfectamineTM. Cell cloning experiment was used to select the best inhibition concentration of PNA, and then LS-174T cells were transfected with this concentration. At the same time, liposome （using LipfectamineTM） group and empty control group were established. The clone formation rate, cancer cell morphology and group growth difference were compared between groups. RESULTS： Cell cloning experiment identified that the best inhibition concentration was 200 nmol/L. The telomerase activity and clone formation rate were notably lower in PNA-transfected group than those in Lipfectamine^TM and empty control group （0.003 ± 0.001 vs 2.334 ± 0.025, 2.528 ± 0.032, P 〈 0.01; 5.20% vs 45.45%, 47.13%, P 〈 0.01）. In the PNA-transfected group, cancer cells showed typical morphological changes, such as becoming round, membrane shrinkage, and nucli concentrating at karyotheca, etc. Group growth curve manifested that the inhibition emerges 11 d after transfection and became notable 15 d or 17 d later. CONCLUSION： PNA can inhibit the growth of LS-174T cells obviously through suppressing telomerase activity.