In vitro synthesis of immunoglobulins and other proteins by dysplastic and neoplastic human mammary tissues.

The synthesis of several proteins in human mammary carcinomas and in dysplastic breast tissues was studied by tissue culture and by immunofluorescence. The synthesis of immunoglobulins showed marked quantitative and qualitative variations from one specimen to another, and a preferential synthesis of immunoglobulin G and C'3 in the carcinomas with lymphocytic infiltration. Fixation of immunoglobulins G and M on the surface of neoplastic cells was noted in some carcinomas. Secretory component was detectable in some cases by immunofluorescence, but no synthesis could be found in vitro, presumably because of unfavorable culture conditions. The synthesis of lactoferrin, casein, and some serum alpha- and beta-globulins was significantly greater in noncancerous tissues than in carcinomas. Synthesis of lactoferrin was also more frequent in the well differentiated carcinomas than in the poorly differentiated carcinomas. The tissue culture technique used in this study, although in need of better adaptation to the requirements in vitro of human mammary tissues, proved to be a useful tool for investigating the synthesis of several protein components by the epithelial cells of cancerous and dysplastic tissues of the human breast. Whether a preferential synthesis of 1 class of immunoglobulins or of other proteins might influence the evolution of a mammary lesion could not be determined in this material but it should be studied further.