Identification of differentially expressed genes involved in the enhancement of mild hyperthermia sensitivity by chroloquine in HSC-3 human oral squamous cell carcinoma cells.

Hyperthermia (HT) is an effective treatment for cancer. When combined with chemotherapy, radiotherapy, or both, HT is expected to show high therapeutic efficacy against various tumors. Chloroquine (CQ), a clinically used treatment for malaria, has been found to inhibit autophagy. CQ has also been reported to enhance thermosensitivity in cancer cells. However, the molecular mechanisms underlying CQ-induced enhancement of thermosensitivity remain unclear. Here, we identified the differentially expressed genes involved in the enhancement of mild HT (MHT) sensitivity by chroloquine in HSC-3 human oral squamous cell carcinoma (OSCC) cells using GeneChip oligonucleotide microarrays. Human OSCC HSC-3 cells were treated with mild hyperthermia (MHT) at 42°C for 90 min, followed by incubation at 37°C for 3 h. Chloroquine (CQ) was added to the culture medium 30 min prior to MHT treatment. Total RNA samples were prepared from the cells, and quality of the RNA was analyzed using a Bioanalyzer 2100. Gene expression was analyzed by an Affymetrix GeneChip system with a GeneChip Human Genome U133 Plus 2.0 array. Sample preparation for array hybridization was carried out as described in the manufacturer’s instructions.