Asamoto M, Toriyama-Baba T, Krutovskikh V, Cohen S M, Tsuda H
Chemotherapy Division, National Cancer Center Research Institute, Tokyo.
Jpn J Cancer Res. 1998 May;89(5):481-6. doi: 10.1111/j.1349-7006.1998.tb03287.x.
We previously demonstrated a clear tendency for actively communicating rat bladder carcinoma cell lines with elevated expression of connexin 43 mRNA to possess strong tumorigenicity. In the present study, immunohistochemical analysis established that normal bladder epithelium did not express connexin 43 protein, but bladder carcinomas often expressed the protein, particularly on the membranes of cells within areas of squamous cell differentiation. To investigate the role of connexin 43 overexpression in rat bladder carcinoma cells, an anti-sense connexin 43 expression vector was transfected into BC31 cells having a high communication capacity. In the resultant transfectants, there was little or no communication capacity and connexin 43 expression. The growth rate in vitro was not changed compared to that of cells treated with the vector alone (without the anti-sense sequence), but tumorigenicity in nude mice was dramatically enhanced. The results indicate that connexin 43 overexpression in rat bladder carcinogenesis is related to squamous cell differentiation, and the protein can have tumor suppressor characteristics, as in other organs.
我们之前证明，连接蛋白43 mRNA表达升高的具有活跃通讯能力的大鼠膀胱癌细胞系明显倾向于具有强致瘤性。在本研究中，免疫组织化学分析证实，正常膀胱上皮不表达连接蛋白43蛋白，但膀胱癌常表达该蛋白，尤其是在鳞状细胞分化区域的细胞膜上。为了研究连接蛋白43过表达在大鼠膀胱癌细胞中的作用，将反义连接蛋白43表达载体转染到具有高通讯能力的BC31细胞中。在所得转染子中，几乎没有或完全没有通讯能力和连接蛋白43表达。与单独用载体（无反义序列）处理的细胞相比，体外生长速率没有变化，但裸鼠体内的致瘤性显著增强。结果表明，大鼠膀胱癌发生过程中连接蛋白43过表达与鳞状细胞分化有关，并且该蛋白与其他器官一样，可能具有肿瘤抑制特性。
