Comments on cultured human sarcoma cells.

Human sarcoma cell populations maintained in culture reflect to the native tumor cells better if the culture retains those nonmalignant cells that comprised the tumor's microenvironment in vivo [Hu M, et al. Characterization of 11 human sarcoma cell strains. Cancer 2002; 95: 1569-76] and thus provide paracrine growth factors and protection from apoptotic death to the tumor cells. Whereas sarcoma cell cultures obtained through meticulous efforts aimed at the elimination of all non-malignant cells of the tumor's original microenvironment consist of subpopulations of tumor cells growing exclusively with the support of their own autocrine growth loops [Sinkovics JG, et al. Growth of human tumor cells in established cultures. In: Busch H, ed. Methods in Cancer Research. Vol 14. New York: Academic Press, 1978; 243-323].