Flow cytometric DNA content of fresh tumor specimens using keratin-antibody as second stain for two-parameter analysis.
Studies concerning flow cytometric assessed DNA content reveal problems in interpretating DNA histograms of tumor specimens. The main problems are histograms with a broad coefficient of variation in the G0/G1 fraction; a high G2M fraction and samples with a low percentage of tumor cells. Therefore, in the present study, 382 fresh tumor specimens of carcinomas were analysed routinely, double labeled with, on the one hand, propidium-iodide for assessing DNA content and, on the other, a monoclonal keratin-antibody for marking epithelial and tumor cells. Of the 311 tumor samples, using single parameter analysis 165 (54%) were classified as DNA aneuploid and 146 (46%) as DNA "euploid." By double parameter analysis, 224 (72%) samples were keratin positive and 87 (27%) keratin negative and, of the 224 keratin positive tumors, 175 (78%) were DNA aneuploid and 49 (22%) DNA euploid. The DNA histograms of single and double parameter analysis were compared and it was concluded that in 24 cases (11%) keratin labeling was necessary to recognize DNA aneuploidy. In another 23 (10%) cases, keratin labeling was helpful in assessing DNA aneuploidy. Finally when the results of the 311 samples were combined, 215 (68%) were scored as DNA aneuploid and 99 (32%) DNA euploid. Thus the overall gain in assessing DNA aneuploidy using the double labeling technique is 14%. In conclusion, it is shown that keratin labeling on fresh tumor cell suspensions of epithelial tumors is of additional value in establishing DNA content. Because single parameter DNA assessment is adequate in approximately 60% of the tested samples, the double labeling technique can be performed routinely, or after initial single parameter DNA assessment. Histograms having a broad CV and/or a high G2M are good candidates for the double labeling technique. Using this technique, DNA-content assessment becomes more reliable.
Department of Pathology, Free University Hospital, Amsterdam, The Netherlands.
J C
JC
van der Linden
C J
CJ
Herman
J G
JG
Boenders
M M
MM
van de Sandt
J
J
Lindeman
D000906:Antibodies / Q000032:analysis* / Q000276:immunology; D002277:Carcinoma / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis*; D004848:Epithelium / Q000737:chemistry / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007633:Keratins / Q000276:immunology*; D011003:Ploidies; D011419:Propidium
D000906:Antibodies; D004273:DNA, Neoplasm; D011419:Propidium; D007633:Keratins