A human breast adenocarcinoma with chromosome and isoenzyme markers similar to those of the HeLa line.

Pleural effusion was obtained from a 51-year-old black woman who had breast adenocarcinoma and had received chemotherapy and radiation therapy after a radical mastectomy. Cytogenetic and isoenzymic analyses of the cells were performed within a few hours of obtaining the sample. Similar analyses were also done with a cell line established from this effusion. The stemline chromosome number was 35, one of the lowest in human neoplasms. In addition to a marker chromosome involving 1q, which is common in human breast tumors, we found several other marker chromosomes whose G-banding patterns were similar to some of the typical HeLa markers. Genetic signature analysis of 15 isoenzyme loci revealed that 13 were identical to those of HeLa. Both HeLa and the cell line described here express glucose-6-phosphate dehydrogenase type a, yet they were derived from heterozygotic individuals (ab). Our data indicate the necessity to extensive cytogenetic and biochemical analysis before conclusions are made that cell lines are actually intercell-line contaminants.