USE OF A MULTIPARAMETRIC PANEL TO TARGET SUBPOPULATIONS IN A HETEROGENEOUS SOLID TUMOR-MODEL FOR IMPROVED ANALYTICAL ACCURACY

The exclusion of non-tumor and dead cells from the analysis of live tu mor cells can significantly improve the accuracy of prognostic indicat ors such as proliferative and DNA indexes. To target live breast tumor cells in a heterogeneous breast tumor model, we have designed a panel consisting of the DNA-specific dye DAPI and epithelial tissue-specifi c (cytokeratin), tumor-associated (MC5), proliferation-associated (pro liferating cell nuclear antigen), and viability-associated (tubulin) m arkers, The breast tumor model consisted of a mixture of equal numbers of live and dead MDA-MB-175-VII (breast tumor) cells, live CEM (leuke mic) cells, and Live peripheral blood mononuclear cells. Targeting the live MDA cells in the mixture by gating on tubulin, cytokeratin, and MC5 resulted in a sevenfold increase in PCNA positivity (from 3% ungat ed to 22.3%), a 60% decrease in the %S-phase fraction (from 37.2% unga ted to 15%), and elimination of extraneous hypodiploid and diploid com ponents, enriching the tetraploid MDAs, These results are consistent w ith those obtained for unmixed Live MDA cells, The combined utilizatio n of this panel and ''cumulative'' electronic gating of the targeted p opulation increases the number of relevant parameters that can be anal yzed per sample and the accuracy of the resultant data. (C) 1995 Wiley -Liss, Inc.