[In situ expression of connexins in various carcinomas].

Background & Objective: Malignant cells are often associated with aberrant expression or localization of connexins. Expression of Cx26, Cx32, Cx43, and Cx45 genes were studied to gain their expression profile in tissue microarrayers consisting of various carcinomas and to elucidate their function in carcinogenesis.

Methods: Basing on the principle of constructing tissue microarrays, the authors take use of self-made tissue arrayer to construct tissue microarrays for the different kinds of cancer specimens. Meanwhile, expression of connexin(Cx) genes, such as Cx32, Cx26, Cx43, and Cx45 in the tissue microarrays were detected in 292 cases of tumor tissues and 89 paratumor tissues by immunohistochemistry.

Results: (1) Three kinds of tissue microarrays consisting samples from 20 different carcinomas were constructed successfully, which contained 360, 200, or 100 spots in each receptive paraffin block with tissue cylinder of 0.75mm or 0.6mm diameter respectively.(2) The expression profiles of Cx32, Cx26, Cx43, and Cx45 in 20 kinds of carcinomas and their related adjacent-cancer tissues were gained, which were widely low expressed in carcinomas especially in nasopharyngeal carcinomas. Expression of Cx26, Cx32, Cx43, and Cx45 in carcinomas such as carcinomas of colon and recta, hepatocellular carcinomas, gastric carcinomas, lung carcinomas and thyroid cancers were significantly lower than their related adjacent-cancer tissues.

Conclusion: Low expression of Cx26, Cx32, Cx43, and Cx45 might play crucial roles in carcinogenesis of many kinds of carcinomas. Tissue microarrays consisting of many different kinds of carcinomas provide a new high-throughout tool for rapid and comprehensive molecular expression profiles of carcinomas, such as connexin genes.