摘要
背景与目的:去甲基化作用可能是三氧化二砷(arsenic trioxide,As2O3)对抗造血系统恶性肿瘤的另一种机制。本研究探讨As2O3对淋巴瘤细胞系T2细胞中抑癌基因酪氨酸磷酸酶(SH2-containinphosphatase-1,SHP-1)的去甲基化作用及对T2细胞生长增殖的生物学影响。方法:T2细胞以As2O3或5-氮杂胞苷(5-aza-2'-deoxyoytidine,5-AC)单独处理,或两药联合处理。采用甲基化特异性PCR、荧光定量PCR和Western检测As2O3处理前后SHP-1基因启动子过甲基化及其mRNA和蛋白表达状况、c-kit蛋白表达变化。MTT法检测细胞存活率。流式细胞术检测细胞凋亡率。结果:As2O3能逆转SHP-1基因启动子甲基化,使T2细胞SHP-1mRNA和蛋白重新表达,同时c-kit蛋白表达呈下降趋势;As2O3明显抑制T2细胞的增殖,随浓度增加及作用时间延长,其增殖抑制效应增加(P<0.05);2.5μmol/L浓度的As2O3作用T2细胞1,2,3d细胞增殖抑制率(9.8%,20.3%,47.5%)明显低于联合作用组(11.0%,36.7%,61.0%)。As2O3可使T2细胞凋亡率增加,且随作用时间延长和浓度增加,凋亡细胞逐渐增多(P<0.05),联合作用组细胞凋亡率(1d:17.3%;2d:37.9%;3d:67.9%)明显高于2.5μmol/LAs2O3单独作用组(6.1%,26.5%,50.9%)。结论:As2O3能去除T2细胞中SHP-1基因甲基化,使其重新表达,并可能通过抑制c-kit受体及其信号转导路径的活化而抑制肿瘤细胞增殖,并诱导细胞凋亡。
Background and Objective. Inducing gene demethylation may be a mechanism of arsenic trioxide （As2O3） in treating hematologic cancers. This study was to investigate the effect of As2O3 on demethylation of SH2- containing phosphatase-1 （SHP-1） in human lymphoma cell line T2 and on the proliferation of T2 cells. Methods： T2 cells were treated with As2O3 and 5-aza-2′-deoxyoytidine （5-AC） alone or in combination. The methylation of SHP-1 in T2 cells was detected by methylation-specific polymerase chain reaction （MSP）. The mRNA and protein expression of SHP-1 were determined by fluorescence quantitative-polymerase chain reaction （FQ-PCR） and Western blot. The expression of p-c-kit was detected by Western blot. Cell proliferation was detected by M-IF assay. Cell apoptosis was detected by flow cytometry. Results. As2O3 led to progressive demethylation and re-expression of SHP-1 in T2 cells, as well as down-regulation of phosphorylated c-kit. As2O3 inhibited the proliferation and promoted the apoptosis of T2 cells, and its effects were enhanced along with the increase of concentration and treatment time （P〈0.05）. The proliferation inhibition rates were significantly lower in As2O3 （2.5 μmol/L） group than in combination （2.5 μmol/L As2O3 plus 2 μmol/L 5-AC） group （9.8% vs. 11.0% on Day 1, 20.3% vs. 36.7% on Day 2, 47.5% vs. 61.0% on Day 3, P〈 0.05）. The apoptosis rates were significantly higher in combination group than in As2O3 group （17.3% vs. 6.1% on Day 1, 37.9% vs. 26.5% on Day 2, 67.9% vs. 50.9% on Day 3, P〈0.05）. Conclusions： As2O3 could cause demethylation and re-expression of SHP-1 in T2 cells, and may inhibit proliferation and induce apoptosis of T2 cells via suppressing activation of c-kit receptor and its signal transduction.
出处
《癌症》
SCIE
CAS
CSCD
北大核心
2009年第3期249-254,共6页
Chinese Journal of Cancer
基金
河北省自然科学基金项目(No.C2005000744)
河北省科技厅指导项目(No.052761615)~~
