The sensitivity of hyperthermo-chemo-radiotherapy for neoplastic cells in vitro on contact-sensitive plates

On plastic dishes, the Chinese hamster cell line (V-79) easily formed colonies and enabled us to examine the effects of various treatments utilizing a colony formation assay while a different human cancer cell line (KSE-1) was found to have a low colony-forming ability which made it difficult to examine when using only a small number of cells. However, on the contact-sensitive plate (CSP), the KSE-1 line was able to form a sufficient amount of colonies in order to conduct examinations. Using CSPs, we were able to investigate the killing effects of various treatments on two malignant cells (V-79 and KSE-1). For the V-79 cells, hyperthermo-chemo-radiotherapy (HCR) was observed to be more effective than any other treatment. For KSE-1 cells, on the other hand, bleomycin had little killing effect, while both radiotherapy alone or hyperthermo-radiotherapy in doses of more than 4 Gy X-ray were found to be effective. These results indicated that it is necessary to examine the sensitivities of cells to different treatments in clinical cases in order to avoid non-effective treatments. In this report, we suggest that the use of CSPs allows for the effective examination of the effects of HCR while using only a small number of malignant cells, which have a low cloning efficiency on plastic surfaces.