Mehta P P, Lokeshwar B L, Schiller P C, Bendix M V, Ostenson R C, Howard G A, Roos B A
Department of Medicine, University of Miami School of Medicine, Florida, USA.
Mol Carcinog. 1996 Jan;15(1):18-32. doi: 10.1002/(SICI)1098-2744(199601)15:1<18::AID-MC4>3.0.CO;2-O.
Gap-junctional communication and expression of gap junction-forming proteins were investigated in normal human prostate epithelial cells and in several malignant prostate cell lines. In comparison with normal cells, gap-junctional communication in malignant cells, as assayed by the transfer of 443-Da fluorescent tracer Lucifer yellow, was either reduced or not detected. Malignant cells expressed mRNA transcripts for connexin (Cx) 43, whereas normal cells expressed mRNA transcripts for Cx32 and Cx40. In both normal and malignant cells, gap-junctional communication was enhanced twofold to fivefold by treatment with forskolin, an agent known to increase intracellular levels of cAMP. Immunocytochemical staining with a Cx43-specific antibody revealed that in malignant cells this enhancement correlated with the number of gap junctions and occurred without any qualitative or quantitative alteration in Cx43 mRNA or protein. Moreover, western blot analyses showed that both control and forskolin-treated malignant cells expressed only one form of Cx43. Our data suggest that gap-junctional communication in both normal and malignant prostate cells may be regulated by hormones that work via a cAMP-dependent signal transduction pathway. Thus, both normal and malignant cells offer a new experimental model system in which interactions between a hormonal form of cellular communication and intercellular communication mediated via gap junctions can be studied.
在正常人类前列腺上皮细胞和几种恶性前列腺细胞系中，研究了间隙连接通讯和间隙连接形成蛋白的表达。与正常细胞相比，通过443道尔顿荧光示踪剂路西法黄的转移测定，恶性细胞中的间隙连接通讯要么减少，要么未检测到。恶性细胞表达连接蛋白（Cx）43的mRNA转录本，而正常细胞表达Cx32和Cx40的mRNA转录本。在正常和恶性细胞中，用福斯高林处理可使间隙连接通讯增强两到五倍，福斯高林是一种已知可增加细胞内cAMP水平的试剂。用Cx43特异性抗体进行免疫细胞化学染色显示，在恶性细胞中，这种增强与间隙连接的数量相关，并且在Cx43 mRNA或蛋白没有任何定性或定量改变的情况下发生。此外，蛋白质印迹分析表明，对照和福斯高林处理的恶性细胞均仅表达一种形式的Cx43。我们的数据表明，正常和恶性前列腺细胞中的间隙连接通讯可能受通过cAMP依赖性信号转导途径起作用的激素调节。因此，正常和恶性细胞都提供了一个新的实验模型系统，在该系统中可以研究细胞通讯的激素形式与通过间隙连接介导的细胞间通讯之间的相互作用。
