The effect of extracellular calcium on colonocytes: evidence for differential responsiveness based upon degree of cell differentiation
| Autor: | Robert R. Buras, F. Davoodi, S. Byers, K. J. Cullen, Russell J. Nauta, Stephen R.T. Evans, Mohsen Shabahang, Lisa M. Schumaker |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
medicine.medical_specialty
Cellular differentiation chemistry.chemical_element Calcium Tritium Epithelium Calcium in biology chemistry.chemical_compound Carcinoembryonic antigen Internal medicine Tumor Cells Cultured medicine Extracellular Humans biology Cell Cycle Cell Differentiation Sodium butyrate Cell Biology General Medicine Alkaline Phosphatase digestive system diseases Carcinoembryonic Antigen Endocrinology chemistry Cell culture Colonic Neoplasms biology.protein Alkaline phosphatase Cell Division Thymidine |
| Zdroj: | Cell Proliferation. 28:245-262 |
| ISSN: | 1365-2184 0960-7722 |
| DOI: | 10.1111/j.1365-2184.1995.tb00067.x |
| Popis: | Calcium supplementation decreases the incidence of colon cancer in animal models and may prevent colon cancer in man. Potential mechanisms include binding of mitogens and direct effects of calcium on colonic epithelial cells. In this study, the effects of extracellular calcium on epithelial cell growth and differentiation were studied in three colon carcinoma and two colonic adenoma cell lines. The characteristics studied included morphology, cell cycle kinetics, [Ca2+]IC (intracellular calcium concentration), proliferation, and expression of differentiation markers such as carcinoembryonic antigen (CEA) and alkaline phosphatase (AP). Sodium butyrate (NaB) and 1,25-dihydroxyvitamin D3 were used as controls in the latter three assays as these two agents are known differentiating agents. Alteration of [Ca+2]EC (extracellular calcium concentration) did not affect carcinoembryonic antigen (CEA) or alkaline phosphatase (AP) expression. NaB enhanced the expression of AP three-fold and CEA five-fold. This effect was augmented by increasing [Ca2+]EC. The exposure of cells to 1,25-(OH)2-Vitamin D3 increased CEA but not AP. [Ca2+]IC increased in response to 1,25-(OH)2-vitamin D3 and NaB but not with variation in [Ca2+]EC. Increased [Ca2+]EC inhibited proliferation of well-differentiated cells, but had no effect on poorly-differentiated cells. Morphological studies showed that extracellular calcium was necessary for normal cell—cell interactions. These studies have demonstrated direct effects of calcium on colonic epithelial cells which may contribute to the protective effects of dietary calcium against colon cancer. Loss of responsivess to the antiprotective effects of [Ca2+]EC with de-differentiation suggests that calcium supplementation may be most beneficial prior to the development of neoplastic changes in colonic epithelium. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|