Inhibitory Effect of Macrolide Antibiotics on Invasion and Proliferation of Lung Cancer Cell Lines

最近有人推测，大环内酯类抗生素除了具有抗菌作用外，还具有抗肿瘤作用，但确切的作用机制尚不清楚。我们检测了大环内酯类化合物对癌细胞侵袭的影响。细胞株为PA-1、HT-1080、A-549和SBC-3。对于大环内酯类抗生素，用10μg/ml的克拉霉素和阿奇霉素，用物质侵袭小室评价大环内酯类抗生素对细胞侵袭的影响。CAM和AZM均能抑制所有细胞株的侵袭。此外，两种大环内酯类化合物均能抑制肺癌患者胸腔积液中分离出的腺癌细胞的侵袭。为探讨大环内酯类化合物对细胞侵袭的抑制作用机制，采用MATRIGEL包被平板和结晶紫染色技术研究了大环内酯类化合物对鳗鱼细胞黏附的影响。CAM和AZM均能抑制所有细胞系的细胞黏附。用流式细胞仪检测了整合素家族的黏附分子CD49c在A-549和SBC-3细胞中的表达。CaM可显著降低CD49c的表达，而Azm则无此作用。抗CD49c单抗可抑制A-549和SBC-3细胞的侵袭。用四甲基偶氮唑盐比色法检测AZM对HT-1080和PA-1细胞的增殖抑制作用，ELISA法检测两种细胞株的凋亡率。这些结果表明，大环内酯类化合物部分通过抑制细胞黏附和增加细胞凋亡率来抑制癌细胞的侵袭。

It has recently been speculated that macrolide antibiotics have an antineoplastic effect besides their antimicrobial one, but the exact mechanism is unknown. We examined the effect of macrolides on invasion of carcinoma cells. Cell lines PA-1, HT-1080, A-549 and SBC-3 were used. For macrolide antibiotics, clarithromycin (CAM) and Azythromycin (AZM) were used at 10 μg/ml. The effect of macrolides on cell invasion was estimated by using a MATRIGEL invasion chamber. Both CAM and AZM inhibited the invasion of all cell lines. Moreover, both macrolides inhibited the invasion of adenocarcinoma cells which were separated from the pleural effusion of patients with lung carcinoma. To determine the mechanism of inhibitory effect on invasion, the effect of macrolides on eell adhesion was estimated by using a MATRIGEL coated plate and crystal violet staining technique. Both CAM and AZM inhibited the cell adhesion in all cell lines. The expression of CD49c, one of the adhesion molecules belonging to the integrin family, was also investigated in A-549 and SBC-3 by flow cytometry. CAM significantly reduced the CD49c expression, but AZM did not. Anti-CD49c monoclonal antibody inhibited the invasion of A-549 and SBC-3. Inversely, AZM but not CAM inhibited the proliferation of HT-1080 and PA-1 by using of MTT assay, and increased the apoptosis of both cell lines by using of ELISA.These results suggest that macrolides suppress the invasion of carcinoma cells partly through inhibition of cell adhesion and through increase of cell apoptosis.