[In vitro tumor sensitivity tests to chemotherapeutic agents by the suppression of dehydrogenase activity]

A test system using dehydrogenase activity for predicting the response to chemotherapeutic agents against cancer cells was introduced. Agar plate assay, INK which test, and SDI test commonly employed in the clinical study were also reviewed. Agar plate assay resembles antibiotic disc sensitivity test. The cancer uniformly suspended in the agar medium was exposed to drugs on paper discs for few hours. After removal of the disc, methylene blue or 2, 6-dichlorophenol indophenol was applied as a dehydrogenase indicator. INK test was introduced by Nishioka et al. in 1957. Several fragments of fresh cancer tissue were incubated with chemotherapeutic agents in roller test tubes. Twenty-four hours later, 2, 6-dichlorophenol indophenol was applied as a dehydrogenase indicator. To develop a simple, rapid, and comparable test, SDI test was introduced by us in 1964. A fresh cancer tissue was minced and made into the cell suspension. After cancer cells were exposed to chemotherapeutic agents, the activities of succinic dehydrogenase of the treated cells were measured by the reduction of 2, 3, 5-triphenyl tetrazolium chloride. Some points to be improved were investigated and discussed.