FDE related signal gene therapy especially melanoma

CAMP和cGMP是细胞内重要的第二信使，介导由不同的细胞外信号启动的生物反应。通过催化环核苷酸的水解，磷酸二酯酶(PDE)调节这些第二信使的细胞内浓度和作用。目前已鉴定出这些酶的至少11个PDE基因家族。一些PDE亚型在各种正常细胞中选择性表达。然而，关于PDE在恶性肿瘤细胞中的表达和功能的报道很少。因此，本研究以四株人口腔恶性黑色素瘤细胞株(HMG、PMP、MMN9和MAA)、人阴道恶性黑色素瘤细胞株(MVH-II)、两株人皮肤恶性黑色素瘤细胞株(G361和C32)、人淋巴结转移性恶性黑色素瘤细胞株(WM-266-4)和人肝腺癌细胞株(SK-Hep-1)为研究对象，研究了PDES在恶性黑色素瘤细胞特别是恶性黑色素瘤细胞中的表达和功能。每株细胞均表达一定数量的PDE。HMG细胞表达PDE3A、PDE3B、PDE4B、PDE4D和PDE7A。PDE4特异性抑制剂促进细胞生长，而PDE3和PDE7特异性抑制剂不改变细胞生长。PMP细胞高表达PDE2，PDE2特异性抑制剂和PDE2 siRNA抑制PMP细胞生长和侵袭。在这些细胞中没有发现PDE基因突变。利用杆状病毒表达载体系统，在Sf9细胞中表达重组PDE。从这些数据来看，PDE信号在恶性黑色素瘤细胞中是非常重要的，可能针对PDE相关信号的基因治疗是有效的。

cAMP and cGMP are critical intracellular second messengers that mediate biological responses initiated by diverse extracellular signals. By catalyzing hydrolysis of cyclic nucleotides, phosphodiesterases (PDEs) regulate intracellular concentrations and effects of these second messengers. At least 11 PDE gene families of these enzymes have been identified. Some PDE isoforms are selectively expressed in various normal cells. However, there are a few reports as to expression and function of PDEs in malignant tumor cells. So, we studied the expression and function of PDEs in malignant tumor cells, especially malignant melanoma cells.Four human oral malignant melanoma cell line (HMG, PMP, MMN9 and MAA), human vaginal malignant melanoma cell line (MVH-II), two human skin malignant melanoma cell line (G361 and C32), human lymph-node metastatic malignant melanoma cell line (WM-266-4), and human liver adenocarcinoma cell line (SK-Hep-1) were used in this study. Each cell line expressed some PDEs. HMG cells expressed PDE3A, PDE3B, PDE4B, PDE4D and PDE7A. PDE4 specific inhibitors stimulated the cell growth, but PDE3 and PDE7 specific inhibitors did not changed the cell growth. PMP cells highly expressed PDE2, and PDE2 specific inhibitor and PDE2 siRNA inhibited the cell growth and invasion. There was no mutation in PDE genes in these cells. By baculovirus expression vector system, recombinant PDEs were expressed in Sf9 cells. From these data, PDE signals are very important in malignant melanoma cells, and maybe gene therapies for PDE related signal are effective.