目的:了解磷酸化细胞信号传导与转录活化因子3(phosphorylated signal tranducers and activators of transcription,p-STAT3)和磷酸化Akt(p-Akt)在黑素瘤中的表达及与肿瘤浸润、转移的关系;方法:采用免疫组化法检测41例黑素瘤和23例色素痣中的p-STAT3和p-Akt,评估它们与肿瘤浸润、转移的关系。结果:p-STAT3在23例色素痣中有2例表达阳性,在41例黑素瘤中有29例表达阳性;p-Akt在23例色素痣中有3例表达阳性,41例黑素瘤中有26例表达阳性,经卡方检验,P<0.05,差异有统计学意义。在黑素瘤中,p-STAT3与p-Akt的阳性表达之间呈正相关,并且p-STAT3和p-Akt的表达阳性率在有浸润或转移的黑素瘤中远高于无浸润或转移的黑素瘤,差异有统计学意义。结论:p-STAT3和p-Akt在黑素瘤的发病、浸润及转移机制中具有重要作用。
In order to investigate the expression of endothelin receptor B （ETR-B） in human malignant melanoma （MM） cells A375 and SK-mel-1 and the proliferative effects of endothelin 3 （ET3） on A375 cells, RT-PCR was applied to detect the expression of ETR-B gene in human MM cells A375 and SK-mel-1. MTT method was used to evaluate the growth enhancing effects of ET3 on A375 cell line in vitro. The results showed that ETR-B gene was expressed in both MM A375 and SK-mel-1 cells. ET3 had stronger ability to enhance the proliferation of A375 cells in vitro in a concentration-dependent manner. It was suggested that ET3/ETR-B might play an important proliferative role in MM.
Summary： Endothelin-3 （ET-3） is aberrantly expressed in both metastatic melanoma tissues and cul tured melanoma cells. Our previous work showed that ET-3 could promote survival of metastatic mela noma cells via its altered expression. In this study, we investigated the mechanisms responsible for these gene-induced phenotypes in melanoma cells. An ET-3 gene sequence-specific shRNA vector pLVTHM-ET3-RNAi was constructed and transfected into human malignant melanoma cells A375 and MMRU, and the resultant molecular events and cellular changes were examined. As compared with the empty-vector group, cell proliferation was slowed down, and the growth inhibition rates were 38.9% in A375 cells and 38.4% in MMRU cells after transfection. In addition, cell invasion capability was also inhibited, with a reduction of 62.2% in A375 cells and 54.3% in MMRU cells. The percentage of apoptotic cells was found to increase. Meanwhile, in both cell lines, secreted protein acidic and rich in cy teine （SPARC） levels were down-regulated together with inhibition of its upstream signaling molecule, NF-kB. Thus, the current results suggested that down-regulated expression of ET3 attenuates the ma lignant behaviors of human melanoma ceils partially by decreasing the expression of SPARC and NF-kB.
