Transforming growth factor-alpha precursors in human colon carcinoma cells.
Among the proteins of the epidermal growth factor family, transforming growth factor-alpha (TGF-alpha) may be an especially reliable indicator of metastasis or prognosis in human colorectal carcinomas. Moreover, anomalous forms of TGF-alpha have been detected in several tissues of cancer origin, suggesting a role of these forms in the development of the disease. This study was designed to identify the presence of TGF-alpha precursors in different colon cancer cell lines by mean of immunocytochemistry and western blotting techniques. Pro-TGF-alpha was detected in all cell lines tested. Staining for pro-TGF-alpha was observed in cytoplasm. Monoclonal antibody to TGF-alpha detected two bands of 20 and 21 kDa. Polyclonal antibody to pro-TGF-alpha revealed five bands ranging from 15 to 24 kDa. All these proteins were also detected in nonmalignant cells expressing a transfected rat pro-TGF-alpha gene. In conclusions, transformation in these human colon carcinoma cells is not due to the presence of anomalous forms of TGF-alpha precursors.
Asbert
M
M
Departament de Biologia Cellular i Anatomia Patòlogica, Universitat de Barcelona, L' Hospitalet de L lobregat, Spain.
Montaner
B
B
Pérez-Tomás
R
R
D000230:Adenocarcinoma / Q000737:chemistry* / Q000473:pathology* / Q000556:secondary; D003110:Colonic Neoplasms / Q000737:chemistry* / Q000473:pathology*; D006133:Growth Substances / Q000032:analysis*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D011498:Protein Precursors / Q000032:analysis*; D016211:Transforming Growth Factor alpha / Q000032:analysis*; D014407:Tumor Cells, Cultured
D006133:Growth Substances; D011498:Protein Precursors; D016211:Transforming Growth Factor alpha; C052268:protransforming growth factor alpha