Lactate dehydrogenase isozymes in teratoma 402AX and other tumor cell lines.

Abstract

Lactate dehydrogenase (LDH) isozymes of mouse teratoma 402AX, teratocarcinoma F9, and human epidermoid carcinoma A431 were studied. The isozyme patterns were analyzed by activity staining of the isozymes on the polyacrylamide gel after electrophoresis of the crude extract of each cell type and by densitometric tracing of the activity bands. The LDH isozyme patterns of 402AX and F 9 cells thus obtained were almost the same as those obtained by DEAE-Sephadex A-50 column chromatography of the extracts. In 402AX cells, LDH-5 and LDH-4 represented about 87 % and 13 %, respectively, of the total lactate dehydrogenase activity. Only trace activity was detected for LDH-3, LDH- 2, and LDH-1. The isozyme pattern of 402 AX cells was similar to that of skeletal mus cle or spleen rather than that of cartilage. Although the treatment of 402AX cells with both retinoic acid and dibutyryl cyclic AMP, which are known to induce cell differentia tion of various teratocarcinoma cell lines, affected the total lactate dehydrogenase activity, the isozyme pattern was not changed.