Transforming growth factor-alpha production and autoinduction in a colorectal carcinoma cell line (DiFi) with an amplified epidermal growth factor receptor gene.

摘要: The DiFi colorectal carcinoma cell line, derived from a patient with familial adenomatous polyposis, was examined for gene expression and production of the autocrine growth factor transforming alpha (TGF-alpha) epidermal receptor (EGFR) copy number. cells expressed TGF-alpha transcripts as identified on Northern (RNA) blots. Addition (10 ng/ml) or EGF to cultures (lacking serum) up-regulated basal mRNA levels, suggesting that autoinduction occurs in these cells. log phase secreted measurable amounts (347 pg/10(6) cells/24 h) into their culture medium, determined by radioimmunoassay. showed strong overexpression EGFR blots relative three other colon cancer lines examined. Immunoperoxidase staining enhanced subpopulation among original (uncultured) ascitic fluid which line established. This observed expand dramatically between passages 1 25. Immune complex kinase assay were functional ability autophosphorylate. not found be rearranged genetically altered using Southern blot analysis. Dot analysis DNA revealed amplification range 60-80 copies/cell, is approximately twice number seen A-431 epidermoid To our knowledge represent first example adenocarcinoma. Because uniquely show auto-induction addition gene, valuable tool studying role(s) regulation tumor growth.