Neoplasm Studies: III. Organization of Cells of Human Tumors in Tissue Culture

Abstract

From time to time the growth of human tumors in vitro has been reported in the literature. In this paper is presented evidence of differentiation in the cellular outgrowths from explants of several human tumors. 1 Differentiation and functional activity have been reported in cultures of normal tissues. A striking example is the observation of Ebeling (1) on thyroid gland epithelium in which colloid-filled cysts were observed in cultures for as long as 129 days in vitro. Chambers and Kempton (2) have also reported the formation of secreting cysts in outgrowing renal epithelium of the chick mesonephros. The differentiations to be described here include the formation of acini in cultures of primary mammary carcinoma and of mixed tumors of the parotid gland, of “pearls” in cultures of metastatic squamous-cell epithelioma, and of endothelial tubes in cultures of angio-endothelioma. Cultures of all these specimens were maintained in a state of active proliferation for at least two months, and in many cases for four months. The most satisfactory culture medium was found to be a mixture of one part chicken blood-plasma, three parts human serum, and one part extract of either mouse or chick embryos in Tyrode solution. No attempt was made to use placental blood and bovine embryonic extract recently recommended by Gey (3). Many cultures were grown in media in which the serum used was from patients with carcinoma or sarcoma, the serum being either homologous or heterologous to the tumors to be grown. No significant differences were observed between growths in such media and in those with normal blood serum. The replacement of human serum with ascitic fluid or with sheep serum was unsatisfactory.