[In vitro cloning of human tumor stem cells].

This study summarizes a one-year work experience in the area of human tumor stem cells cloning techniques. We found that it was more advisable to use an enzymatic method for dissociating solid tumors. The breast tumors possessing an unfavourable histoprognostic grade were found to grow up more easily in culture, which is a confirmation of known relationships between cell differentiation degree and cell proliferation. The high frequency of failures in the obtention of colonies did not allow to use this technique in daily clinical practice to study the in vitro sensitivity to drugs of a definite tumor. An improvement in the conditions of culture and the comparison with other in vitro methods for the prediction of response to oncostatics--particularly the incorporation of radioactive precursors (Livingston and coll., 1980)--will be attempted in future work.