Early synergistic interactions between the HPV16-E7 oncoprotein and 17β-oestradiol for repressing the expression of Granzyme B in a cervical cancer model

Although high-risk human papillomavirus (HR-HPV) infection has a prominent role in the aetiology of cervical cancer (CC), sex steroid hormones may also be involved in this process; however, the cooperation between oestrogen and HR-HPV in the early stages of cervical carcinogenesis is poorly understood. Since 17β-oestradiol (E(2)) and the HPV type 16-E7 oncoprotein induce CC in transgenic mice, a microarray analysis was performed in the present study to generate global gene expression profiles from 2-month-old FVB (non-transgenic) and K14E7 (transgenic) mice who were left untreated or were treated for 1 month with E(2). Upregulation of cancer-related genes that have not been previously reported in the context of CC, including glycerophosphodiester phosphodiesterase domain containing 3, interleukin 1 receptor type II, natriuretic peptide type C, MGAT4 family member C, lecithin-retinol acyltransferase (phosphatidylcholine-retinol-O-acyltransferase) and glucoside xylosyltransferase 2, was observed. Notably, upregulation of the serine (or cysteine) peptidase inhibitor clade B member 9 gene and downregulation of the Granzyme gene family were observed; the repression of the Granzyme B pathway may be a novel mechanism of immune evasion by cancer cells. The present results provide the basis for further studies on early biomarkers of CC risk and synergistic interactions between HR-HPV and oestrogen.