Biology of colorectal and gastric cancer cell lines

Cell lines established from the human colorectal and gastric cancers may provide very useful tools to the study of the disease and to develop and test new therapeutic approaches, and a large bank of well-characterized cell lines should reflect the diversity of tumor phenotypes and provide adequate models for the study of tumor heterogeneity. Colorectal lines are relatively easy to establish, while gastric cancer cell lines remain extremely difficult to propagate in long-term culture, and the number of cell lines is very limited. In this paper, we describe the up-to-date results of the characteristics of our nine colorectal cancer cell lines and four gastric cancer cell lines. Based on culture, xenograft, and ultrastructural morphologies, these cell lines could be subtyped into well-differentiated, moderately differentiated, poorly differentiated, and mucinous carcinomas. Basic properties concerning expression and secretion of antigens, neuroendocrine features, receptor binding of various gastrointestinal hormones and neurotransmitters, cytogenetic studies, gene amplification and expression, and chemosensitivity profiles are described. In particular, a greater number of receptors for hormones and neurotransmitters are expressed on human colorectal cancer cell lines compared to gastric cancer cell lines, raising the possibility that gastrointestinal hormones may have a greater autocrine effect on colon cancer cell growth. Despite major differences in the biology of colorectal cancer and gastric cancer as indicated by clinical studies, the multiple properties that we examined reveals marked similarities between the colorectal and gastric cancer cell lines. However, in vitro chemosensitivity patterns to cytotoxic drugs are very different in colorectal and gastric cell lines. Some of these observations may be due to the relatively low expression of the multidrug-resistance-associated (MDR1) gene in gastric cancer cell lines. In addition, colorectal cancer cell lines express receptors for peptide hormones more frequently.