Wang Tian-Li, Huang Jian-An, Yu Ge-Hua, Mao Yi-Xiang, Wang Guang-Jie, Zhang Xue-Guang
Department of Respiratory Medicine, the First Affiliated Hospital, Soochow University, Suzhou, Jiangsu 215 006, P.R. China.
Ai Zheng. 2004 Nov;23(11):1278-82.
BACKGROUND & OBJECTIVE: Although the roles of CD40 in B cells have been intensively studied, little is known on the function of CD40 in lung cancer cell lines. This study was to investigate biological effects of soluble CD40 ligand (sCD44L) on lung cancer cell line A549 (CD40 positive), and its possible mechanism.
A549 cells were co-incubated with sCD40L, cell proliferation was detected by MTT assay and 3H-TdR incorporation method. Immunofluorescence technique and flow cytometry (FCM) were used to evaluate changes in cell phenotypes and cell cycle. Cell apoptosis, and expression changes of Bcl-2 and Bax were observed by FCM, reverse transcriptase-polymerase chain reaction (RT-PCR), and Western blot.
Compared with control cells, proliferation of A549 cells co-incubated with sCD40L was inhibited (P< 0.05). Positive rates of cell surface molecules, CD49e, CD54, TNFRI, and CD95L, in A549 cells co-incubated with sCD40L for 72 h were (61.2+/-4.8)%, (31.2+/-6.1)%,(42.7+/-5.9)%, and (38.2+/-3.4)%, respectively, while those in control cells were (34.7+/-2.1)%, (7.1+/-1.6)%, (15.2+/-4.1)%, and (10.1+/-2.3)%, respectively (P< 0.05). However, positive rate of TNFRII in A549 cells co-incubated with sCD40L[(8.7+/-0.8)%] was lower than that in control cells [(58.1+/-3.6)%] (P< 0.05). G1 phase of A549 cells treated with sCD40L for 72 h was (76.0+/-9.1)%, more than that of control cells [(56.7+/-6.9)%], while S phase of sCD40L-treated A549 cells [(10.3+/-5.7)%] was less than that of control cells [(32.7+/-5.5)%]. No significant apoptosis of A549 cells was observed after co-incubated with sCD40L for 72 h, but Bax expression was up-regulated.
sCD40L may inhibit cell proliferation, cause changes in phenotype and cell cycle of A549 cells, and alter expression of apoptosis-associated gene, such as Bax.
尽管CD40在B细胞中的作用已得到深入研究，但对其在肺癌细胞系中的功能了解甚少。本研究旨在探讨可溶性CD40配体（sCD40L）对肺癌细胞系A549（CD40阳性）的生物学效应及其可能机制。
将A549细胞与sCD40L共同孵育，采用MTT法和3H-TdR掺入法检测细胞增殖。运用免疫荧光技术和流式细胞术（FCM）评估细胞表型和细胞周期的变化。通过FCM、逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹法观察细胞凋亡以及Bcl-2和Bax的表达变化。
与对照细胞相比，与sCD40L共同孵育的A549细胞增殖受到抑制（P<0.05）。与sCD40L共同孵育72小时的A549细胞表面分子CD49e、CD54、TNFRI和CD95L的阳性率分别为（61.2±4.8）%、（31.2±6.1）%、（42.7±5.9）%和（38.2±3.4）%，而对照细胞分别为（34.7±2.1）%、（7.1±1.6）%、（15.2±4.1）%和（10.1±2.3）%（P<0.05）。然而，与sCD40L共同孵育的A549细胞中TNFRII的阳性率[（8.7±0.8）%]低于对照细胞[（58.1±3.6）%]（P<0.05）。用sCD40L处理72小时的A549细胞G1期为（76.0±9.1）%，高于对照细胞[（56.7±6.9）%]，而sCD40L处理的A549细胞S期[（10.3±5.7）%]低于对照细胞[（32.7±5.5）%]。与sCD40L共同孵育72小时后，未观察到A549细胞明显凋亡，但Bax表达上调。
sCD40L可能抑制A549细胞增殖，导致其表型和细胞周期改变，并改变凋亡相关基因如Bax的表达。
