cAMP类似物对人肺癌细胞生长抑制及诱导分化作用

Effect of the two cAMP Analogs on Human Lung Cancer Cell Line PGCC

目的 研究 2种cAMP类似物 ,DBcAMP (无位点选择性 )和 8-Cl -cAMP (位点选择性 )对高转移人肺癌细胞系PGCC细胞生长及分化的调控作用。方法 采用MTT法、Boydern小室法和软琼脂集落形成实验检测PGCC细胞体外生长、浸润及集落形成能力 ,观察用药后PGCC细胞形态、神经特异性烯醇化酶 (NSE)和嗜铬素的表达。结果 DBcAMP 1mmol/L处理第 8天 ,对PGCC细胞生长的抑制率为 30 % ,8-Cl -cAMP抑制率为 75 %～ 80 % ,磷酸二酯酶抑制剂IBMX与 8-Cl -cAMP合用没有增加其抑制作用 ,而与DBcAMP合用则有明显协同作用。 2种药物处理后 ,PGCC细胞浸润及集落形成能力均降低 ,且 8-Cl -cAMP的作用强于DBcAMP。光镜见处理细胞突起伸长或增多。结论 8-Cl -cAMP和DBcAMP可能通过不同的机理抑制PGCC细胞的生长和浸润 ,具有PKAⅡ位点特异性的cAMP类似物 ,8-Cl -cAMP是 1个新的有效的肿瘤抑制剂。

Objective To study the effect of two cAMP analogs,8-Cl-cAMP(with site-selective for PKAⅡ) and DBcAMP(non-site-selective) on growth and differentiation of highly metastatic human lung cancer cells PGCC.Methods The growthin vitro,invasion and colony formation of the PGCC cells were assessed byMTT method,Boydern Chamber method and soft agar colony formation assay.The expression of neuron-specific enolase(NSE) and Chromogranin in PGCC cells was detected by HE and immunocytochemistry before and after treatment of 8-Cl-cAMP and DBcAMP.Results At the 8th day of the treatment,the inhibition rate of PGCC cells was much lower in group with DBcAMP(1 mmol/L) than in group with 8-Cl-cAMP(10～20 mmol/L)(30% vs.75%～80%).When phosphodiesterase inhibitor IBMX was added simultaneously,the inhibitory effect of 8-Cl-cAMP was not enhanced,but that of DBcAMP was significantly enhanced.8-Cl-cAMP had a stronger effect on the ability of PGCC cells to penetrate matrigel-coated membrane and to form colonies in soft agar than did DBcAMP.Microscopic observation showed the formation of elongated cytoplasmic processes after drug therapy.The expression of NSE and Chromogranin increased after treatment.Conclusion The inhibition effect of 8-Cl-cAMP and DBcAMP on PGCC cells growth and invasion may be mediated by different mechanisms.The results suggest that 8-Cl-cAMP,a PKAⅡ site-specific cAMP analogue is a new effective tumor inhibitor.