Clonogenic growth of tumor cells in vitro

: We expose here our first results concerning clonogenic growth of 40 cases of malignant tumor plated in semi-solid medium (methylcellulose). The growth is determined by the presence at day 21 of colonies (cellular group with more than 60 micron diameter). 26 cases were considered significant. A 61% growth has been observed with primary solid tumors, and 83.4% with ascites, ovarian carcinoma growing the best. Cellular viability, plating efficiency and when the cellular number allowed it, linear graphic curves have been established. An ultrastructural morphological study, illustrated here by 2 cases--one ovarian carcinoma and one colonic adenocarcinoma cell line--has shown that all colony 's cells belong to a same cellular type and present various degrees of differentiation, suggesting a possible analogy between our observations and the hypothetical tumor cell model, concerning human carcinoma's organisation and self renewal.