Heterogeneity of expression of the calcium-binding protein calretinin in human colonic cancer cell lines.

We searched for the presence of calretinin (CR) in 12 colonic cancer cell lines using immunohistochemistry, Western blot analysis and the reverse transcriptase-polymerase chain reaction (RT-PCR). We were able to demonstrate that calretinin is expressed in the cell lines HT-29, WiDr, LoVo, LS180, CO112, CO115. SW480, SW620, COLO205 and SK-CO-1, while no detectable amounts were found in the cell lines SW1116 and Caco-2. In general, rapidly proliferating cell lines expressed calretinin, whereas the protein was absent from cell lines with a low multiplication rate. A possible role for calretinin in maintaining the proliferative cycle of tumor cells is discussed.