Effects of hyperthermia on the expression of E6 and E7 genes of human papillomavirus type 6 and 11

Abstract

Objective To investigate the effect of hyperthermia on the expression of E6 and E7 genes of human papillomavirus (HPV) type 6 and 11 in HPV-infected human skin. Methods Tissue samples were obtained from the lesions of condyloma accuminatum (CA) in 6 patients after informed consent. Each sample was divided into 4 parts: one was embedded and directly stored at -80 ℃; the other 3 parts were placed in culture medium and the surface of the samples was irradiated for 30 minutes with a thermotherapy apparatus at 37℃, 42 ℃, 45 ℃, respectively, then the samples were taken out and stored at -80 ℃. RNA was extracted from the specimens, real time quantitative PCR (qPCR) was performed to detect the expression of E6 and E7 genes of HPV-6 and -11. Results Of the 6 patients, 2 were infected with HPV-6 and -11 respectively, 4 with both HPV-6 and HPV-11. The expression of E6 and E7 mRNA decreased with the increase in irradiation temperature. The relative mRNA expression levels at 37 ℃, 42 ℃ and 45 ℃ were 1.00 ± 0.00, 0.61 ± 0.17, 0.27 ± 0.15, respectively, for HPV-6 E6 gene, 1.00 ± 0.00, 0.56 ± 0.21, 0.16 ± 0.11 respectively, for HPV-6 E7 gene, 1.00 ± 0.00, 0.60 ± 0.22, 0.16 ± 0.08, respectively, for HPV-I1 E6 gene, 1.00 ± 0.00, 0.55 ± 0.15, 0.24 ± 0.06, respectively, for HPV-11 E7 gene; statistical difference was noted among them between the specimens irradiated at different temperature (all P < 0.01). Conclusion Hyperthermia can remarkably suppress the expression of HPV-6/I 1 E6 and E7 genes, which may be a possible mechanism under the regression of warts induced by local hyperthermia. Key words: Human papillomavirus 6; Human papillomavirus 11; fever, Papillomavirus E7 proteins