Premature chromosome condensation--studies on human metastatic carcinoma cells.

Utilizing the phenomenon of premature chromosome condensation (PCC) studies were carried out on interphase chromatin of metastatic cells from 52 cancerous effusions obtained from 45 patients presenting with various solid carcinomas. A highly individual pattern of distribution of the various interphase stages was detected, reflecting the heterogeneity of human solid tumors in an advanced stage. Nevertheless a variety of clinical, biologic, and technical factors were examined for their possible influence on these PCC patterns. The duration in culture was one of the influencing factors, as were the time lapse between the first diagnosis and the sampling of the respective effusion, or the nature of cytostatic therapy. Cytogenetic equivalents of gene amplification, as represented by "double minutes", could be found in the prematurely interphase chromatin of 35 of the 52 effusions. G1-PCC proved to be most reliable with regard to screening of double minutes. In addition, an adequate quality of Giemsa banding was achieved in PCC of 21 out of 24 effusions yielding a sufficient number of well-spread PCC. In six of these 21 cases PCC was superior to metaphase analysis in obtaining karyotypes, while the same was true for 14 of the 52 effusions screened for double minutes. Thus the PCC technique was shown to be an indispensable additional source of cytogenetic information in cells of human solid tumors.