Ultrasound hyperthermia enhances chemo-sensitivity in oral squamous cell carcinoma by TRIF-mediated pathway

Hyperthermia is currently used as an alternative to surgery or in combination with chemotherapy and/or radiation therapy in the treatment of oral squamous cell carcinoma. However, little has been known about the change in chemo-sensitivity after hyperthermia and the mechanism underlie it in oral squamous cell carcinoma.

The aim of this study was to explore the influence of chemo-sensitivity of CAL-27 and SCC-4 cells by histoculture drug response assay after the animal model treated by the ultrasound hyperthermia. Then, we conducted a microarray between xenograft after hyperthermia at 42°C for 45 minutes and that with no treatment. We further confirmed the expression of TRIF in hyperthermia by immunohistochemistry, RT-PCR and Western blot.

The chemo-sensitivity to five kinds of drugs demonstrated ultrasound hyperthermia performed in 42°C for 45 minutes would reach the highest inhibition rate in CAL-27 and SCC-4 cells. The microarray dataset revealed that 847 mRNA were upregulated and 1031 were downregulated. GO and pathway analyses indicated that they play an important role in translational initiation, nucleoplasm, and poly (A) RNA binding in the hyperthermia process. We further confirmed the expression of TRIF was downregulated in hyperthermia along with inactivation of NF-κB pathway.

The experiments confirms the rationality of synchronous combination of hyperthermia and chemotherapy and may provide a better treatment that the use of sensitivity testing in such cases may lead to individualized, more effective therapy.