目的探讨肿瘤坏死因子-α(TNF-α)和NF.KB在人单核巨噬细胞系(THP-1)细胞促煤焦沥青烟气提取物(CTPE)诱导人支气管上皮细胞系(BEAS-2B)细胞恶性转化中的作用。方法在第10代BEAS-2B和THP-1细胞共培养组中分别加入NF—KB的抑制剂一吡咯烷二硫代氨基甲酸(PDTC)和TNF-α中和抗体,用细胞周期检测、染色体核型分析和软琼脂集落形成实验检测第20代PDTC组和TNF-α中和抗体组BEAS-2B细胞的恶性转化情况,并与第10代、第20代共培养组进行比较;采用实时定量PCR和免疫印迹法(Westernblot)法检测各组BEAS.2B细胞中TNFR相关因子2(TRAF2)和细胞周期蛋白D1(CyclinDl)基因及其蛋白的表达。结果第20代PDTC组和TNF-α中和抗体组BEAS.2B细胞中S期细胞的比例分别为(33.97%±2.16%)和(34.29%±2.04%),明显低于第20代共培养组(44.46%±0.83%%),差异有统计学意义(P〈0.05)。第20代PDTC组和TNF-α中和抗体组100个细胞中出现异常染色体核型的细胞数量为40个和37个,而第20代共培养组为75个,差异有统计学意义(P〈0.05)。第20代PDTC组软琼脂集落形成数(15.17±2.48)个,集落形成率为(1.51‰±0.25‰),第20代TNF—α中和抗体组集落形成数为(13.33±2.58)个;集落形成率为(1.33‰±0.26‰),均明显低于20代共培养组[集落形成数:(172.33±12.09)个和集落形成率:(17.23‰±1.20‰)],差异有统计学意义(P〈0.05);PDTC组和TNF.d中和抗体组TRAF2和CyclinD1基因及其蛋白的表达明显低于第20代共培养组,差异有统计学意义(P〈0.05)。结论TNF.仅和NF-KB在THP-1细胞促进煤焦沥青烟气提取物诱导BEAS-2B细胞恶性转化的早期阶段发挥重要的作用,并可能通过影响TRAF2和CyelinD1的表达促使细胞恶性变发生。
Objective To characterize the role of tumor necrosis factro-ot (TNF-α) and NF-KB play a role in macrophage-like THP-1 cells promoting coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells (BEAS-2B). Methods From passage 10, CTPE-induced BEAS-2B cells co- cultured with THP-1 cells were treated with NF-KB inhibitor-Pyrrolidine dithiocarbamate (PDTC) every 3 passages and TNF-α antibody every passage. Alterations of cell cycle, karyotype and colony formation in soft agar of BEAS-2B cells at passages 20, indicative of tumorigenecity, were determined, respectively. In addition, mRNA and protein levels of TNF receptor associated factor2 (TRAF2) and Cyclin D 1 in BEAS-2B cells were measured with Real Time-PCR and Western blot, respectively. Results The percentages of S-phase BEAS-2B cells at passage 20 in PDTC group and TNF-α antibody group were (33.97±2.16)% and (34.29±2.04)% respectively, which were less than that in Co-euhure+CTPE group of 20th passage [(44.46±0.83)%], P〈O.05; The number of cells with aneuploidy in 100 cells in 20th passage PDTC group and TNF-α antibody group were 40 and 37, and there were significantly different when comparing to that of 20th passage Co-euhure+CTPE group (75); The number of colony formation and the rate of colony formation of BEAS-2B cells in soft agar at passage 20 in PDTC group were ( 15.17 ±2.48) and ( 1.51‰±0.25‰), ( 13.33±2.58) and ( 1.33‰±0.26‰) in TNF-α antibodygroup, which were less that those in 20th passage Co-cuhure+CTPE group [(172.33±12.09) and (17.23‰± 1.20‰)], P〈0.05; at the same time, the mRNA and protein levels of TRAF2 and Cyclin D1 in BEAS-2B cells were decreased after PDTC and TNF-α antibody treatment. Conclusion TNF-α and NF-KB could play an important role in THP-1 cells promoting coal tar pitch extract-induced tumorigenic transformation of BEAS-2B cells by influencing the expression of TRAF2 and Cyelin D1.