Establishment and characterization of a human rectal neuroendocrine cell carcinoma in vitro.

Human colorectal neuroendocrine cell carcinoma ( NECC ) is uncommon. Treatment of the disease has not yet been established, and NECC of the colon and rectum behave clinically more aggressively than their exocrine counterparts, so the prognosis is generally worse. One reason for the lack of established treatment is that there are no model systems of this disease. There have been a few reports on cell lines from neuroendocrine tumors, because these tumors are difficult to culture, and there are even fewer reports on colorectal carcinoma cell lines with neuroendocrine features. We therefore attempted to establish a permanent cell line in order to investigate the biological behavior and treatment of NECC. The cell line we succeeded in culturing is called N-TAK1. Gastrin promotes the growth of gastrointestinal epithelial cells and also stimulates the growth of gastrointestinal cancers. Hormone-receptor antagonists restrict the growth of hormone-dependent tumors. The growth of colon cancer was promoted by the application of gastrin, whereas it was restricted by proglumide, which is known to be a gastrin receptor antagonist. We demonstrated that gastrin has a stimulatory effect on the growth of N-TAK1 cells and that it could be detected by immunohistochemistry in the cells. We also showed that proglumide inhibited the growth effect of gastrin.