OBJECTIVETo study the effect of hyperthermia on expressions of multidrug resistance (MDR) genes in tongue squamous cell carcinoma cell line Tca8113 and its MDR cell line Tca8113/CBDEA and intracellular ADM concentration.

METHODSCell lines were hyperthermia-treated (42 degrees C for 0.5 h), 4 h and 24 h later real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) detected expressions of MDR relative genes (MDR1, MRPI, GST-pi) and HTS 7000 Plus Bio Assay Reader measured intracellular ADM concentration.

RESULTSExpressions of MDR1, MRPI, GST-'pi genes in Tca8113/CBDEA significantly descended at 4 h and 24 h post-hyperthermia (P < 0.01). Expressions of MDR1, MRP1 genes in Tca8113 significantly descended at 4 h and 24 h post-hyperthermia (P < 0.05), but there was not statistical difference between 4 h and 24 h post-hyperthermia. GST-pi expression had not statistical descent at 4 h, but there was significantly descend at 24 h post-hyperthermia (P < 0.01). Drug tolerance decreased and hyperthermia increased intracellular drug concentration in Tca8113/CBDEA and Tca8113 (P < 0.01).

CONCLUSIONHyperthermia enhance chemotherapy effect and reverse MDR genes expression in tongue squamous cell carcinoma cell line. It is suggested that hyperthermia could be used as a method to overcome MDR, which is worth more investigation.