Presence of circulating anti-c-myb oncogene product antibodies in human sera.

Bacterially expressed mouse c-myb protein was purified from E. coli extracts and used as antigen to screen human sera for circulating anti-c-myb oncogene product antibodies. Using Western blotting, we have found that human sera contain IgG antibodies to the c-myb gene product. The percentage of positive sera in cancer patients appears to be dependent upon cancer type and is significantly higher in breast-cancer patients than in normal donors: 43% of sera from breast-cancer patients are positive, whereas in neuroblastoma cancer patients the production of IgG anti-c-myb appears to be rare. No significant correlation was observed between the presence of circulating anti-c-myb antibodies and the expression of the c-myb gene in breast tumors.