Potentiation of Anticancer Activity of G(2)/M Blockers by Mild Hyperthermia.

BACKGROUND/AIM: Hyperthermia (HT), combined with chemotherapy, has been used to treat various types of cancer. This study aimed to investigate the HT-sensitivity of malignant and non-malignant cells, and then evaluate the combination effect of docetaxel (DTX) and a newly synthesized chromone derivative (compound A) with HT. MATERIALS AND METHODS: The number of viable cells was determined using the MTT method. Cell cycle distribution was analyzed using a cell sorter, and DNA fragmentation pattern was detected using agarose gel electrophoresis. RESULTS: Among 12 cultured cells, oral squamous cell carcinoma (OSCC), especially Ca9-22 cells, and myelogenous leukemia cells showed higher sensitivity to HT than lung carcinoma and glioblastoma cell lines, while normal oral cells were the most resistant. Cytotoxicity of DTX on Ca9-22 cells was maximum at 41-42 degrees C and 45~60 min exposure to HT. DXT, compound A, and HT induced G(2)/M arrest of Ca-22 cells. Mild HT enhanced the DTX- and compound A-induced subG(1) arrest, in a synergistic fashion. CONCLUSION: The combination G(2)/M blockers and mild-HT can potentially be used for the treatment of OSCC.