Schwaller B, Meyer-Monard S, Gander J C, Pugin P, Celio M R, Ludwig C
Institute of Histology and General Embryology, University of Fribourg, Switzerland.
Anticancer Res. 1998 Sep-Oct;18(5B):3661-7.
Calretinin-22k (CR-22k), an alternatively spliced form of calretinin (CR) belongs to the EF-hand family of calcium-binding proteins and is expressed in several colon adenocarcinoma cell lines (e.g. WiDr, HT-29).
Serum samples of cancer patients were screened with a sandwich ELISA technique using the CR-specific antiserum 7696. Highly positive samples were analyzed by Western blots and immunohistochemistry.
CR-22k was detected in the serum of several patients and values were as high as 0.19 microgram/ml. Western blot analysis confirmed the identity of the bound protein as CR-22k. The highest concentrations were detected in patients with colon or breast cancer, but also in a patient with ischemic necrosis of the gut. CR immunoreactivity was localized to epithelial cells, nerve fibres, cells of the connective tissue and to mesothelial cells.
Our results establish that CR-22k is detectable in the serum of cancer patients under specific pathological conditions.
