Effect of hyperthermia on multidrug resistance of tongue squamous cell carcinoma cell line (Tca8113) and its multidrug resistance cell line Tca8113/CBDEA / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Cell 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.</p><p><b>RESULTS</b>Expressions 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).</p><p><b>CONCLUSION</b>Hyperthermia 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.</p>

Expression and implication of Pgp, MRP, LRP, GST-pi, Topo II alpha in tongue squamous cell carcinoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the correlation of chemotherapy efficacy in tongue squamous cell carcinoma(SCC) with expression level of P-glycoprotein(Pgp), multidrug resistance-associated protein (MRP), lung resistance-related protein (LRP), glutathiones-tranferase (GST-pi), DNA topo-isomerase II alpha (Topo II alpha).</p><p><b>METHODS</b>The expression patterns of Pgp, MRP, LRP, GST-pi and Topo II alpha in 40 patients (pre and post-chemotherapy, respectively) with tongue SCC were examined by immunohistochemically labelled streptavidin bioein method (LsAB).</p><p><b>RESULTS</b>The expression ratios of Pgp, MRP, LRP, GST-pi and Topo II alpha in pre-chemotherapy cases were 47.5%, 50%, 35%, 45%, 82.5%, respectively. No relations between expression of Pgp, MRP, LRP, GST-pi, Topo II alpha and clinic indexes were established (P > 0.05). Expression ratios of Pgp, MRP in post-chemotherapy cases were higher than that in pre-chemotherapy cases (P < 0.05). Expression of Pgp and MRP showed relevance with drug resistance (P < 0.05). The co-expression was common, the ratios of co-expression of Pgp, MRP, GST-pi and MRP, GST-pi in chemotherapy non-responders were 40% and 50%, respectively, but 0 in responders.</p><p><b>CONCLUSION</b>The intrinsic multidrug resistance of tongue SCC is relevant to the effects of Pgp, MRP, GST-pi.</p>