Differential pp60c-src activity in well and poorly differentiated human colon carcinomas and cell lines.
The results presented in this report demonstrate increased pp60c-src kinase activity associated with moderate to well differentiated colon tumors, corroborating previous observations by other groups. Extension of this analysis to include a small number of poorly differentiated colon carcinomas revealed src kinase activity comparable to that observed in normal colonic mucosa, considerably less than that observed in moderate/well differentiated lesions. Correlations of src kinase activity with differentiation was confirmed within a panel of colon cell lines where increased activity, associated with moderate/well differentiated lines, was accompanied by increased expression of pp60c-src protein. Use of an antiphosphotyrosine antibody in immunoprecipitation revealed the presence of novel phosphotyrosyl cellular substrates in human colon cell lines displaying elevated pp60c-src kinase activity. These observations suggest a role for the src protooncogene in colonic differentiation pathways.
Weber
T K
TK
Department of Surgery, New England Deaconess Hospital, Boston, Massachusetts 02115.
Steele
G
G
Summerhayes
I C
IC
D002454:Cell Differentiation; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D010750:Phosphoproteins / Q000032:analysis; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000032:analysis* / Q000502:physiology; D014407:Tumor Cells, Cultured
D010750:Phosphoproteins; D016392:Proto-Oncogene Proteins pp60(c-src)