[A study on sensitivity testing of ovarian cancer cells to anticancer chemotherapy - with special reference to the use of LDH and its isozymes as indicators (author's transl)].

The malignant ovarian cancer cells removed on operation were cultured and exposed to the anticancer drug (either 5-fluorouracil or mitomycin C) for 30 minutes or 24 hours respectively. The activity of the LDH and LDH isozyme in the culture medium was measured. Also the activity of the LDH and its isozyme was determined in the patients undergoing chemotherapy with either 5-fluorouracil or mitomycin C. The results are summarized as follows: 1) The LDH isozyme pattern of the culture medium prior to exposure of malignant cells to the anticancer drugs was classified into 2 types i.e., M type which is characterized by a predominance of LDH4,5 (referred hereinafter to as group M) and H type with a predominance of LDH1,2 (referred to as group H). 2) Of 11 cases studied, 7 were classified as group M and 4 were categorized as group H. there was no distinct relationship between histological type and LDH isozyme pattern. 3) In the group with exposure to anticancer drugs the total LDH activity in both group H and group M was lower than in the control group. Control specimens in group H showed increased total LDH activity. 4) The H/M ratio based on subunits of LDH isozyme was virtually unchanged by exposure to anticancer drugs in group M, while rapidly lowered by the same treatment in group H. 5) The death rate of malignant cells as estimated by dye exclusion methods was higher with exposure to anticancer drugs than without it. 6) The serum LDH was more markedly lowered after treatment in group H than in group M. However, there was no substantial difference between the two groups in M/H ratio before and after treatment.