HPV18 E6 and E7 Intratumour Heterogeneity in Esophageal Cancer

Abstract

The development of esophageal cancer accompanied by the presence of human papillomavirus (HPV) DNA into the host genome. By evaluating the expression of this virus for tumor cell origin and also their cell grows and migrations, we examined esophageal cancer clonality in the context of intra-tumor heterogeneity. In this research, we have checked the expression of HPV18 E6 and E7 in different single cell clones by the manual cell picking method in the HPV positive esophageal cancer (EC109), EC109 cell line used as a negative control, and Hela cell line used as the positive control. Quantitative real-time PCR (QRT-PCR) was run to detect the expression levels of HPV E6 and E7, Cell Counting Kit-8 (CCK-8) assay was used to examine cell proliferation, invasion assays performed using Costar chambers and wounding assay to study cell migrations in vitro. We investigated the intra-tumor heterogeneity of HPV E6 and E7 in esophageal cancer and the evaluation of the growth and migrations at the clonal level, using 10 single cell clones. In particular clones, C7 & C10 displayed a highly variable expression in both HPV E6 and E7 and weak in four clones (C1, C3, C4, and C9) consequently, the cell invasion, proliferation, and migration increase with increasing the level of HPV expression and inverse. In conclusion, the resulting based on single cell cloning showed the relationship between HPV and cell growth and migration in esophageal cancer. Future study in HPV DNA integration needed to explore the mains specific integration site of HPV DNA in esophageal cancer and molecular monitoring of the HPV for future prevention researches and also effective therapeutic strategies.

A Drosophila model of HPV16-induced cancer reveals conserved disease mechanism

“…We have reported similar observations for a HPV18 E6-induced effect, in which only a subset of the cell population co-expressing E6 and activated Ras were transformed to cancer-like cells and those were the cells that expressed higher levels of E6 oncogene [ 49 ]. Single-cell clone analysis of HPV18 E6 and E7 positive human esophageal cancer cells also showed that the intra-tumor heterogeneity is due to variation in the level of E6 and E7 expression, with cells expressing higher levels exhibiting cell proliferation and invasive behavior [ 89 ]. Hence, the Drosophila model could be a valuable in vivo system for understanding the mechanisms underlying the intra-tumor genetic heterogeneity, which is currently a great problem in the treatment of cancers including HPV-associated cancers [ 90 , 91 ].…”