Identification of E6/E7-dependent microRNAs in HPV-positive cancer cells

Abstract

Oncogenic types of human papillomaviruses (HPVs) are closely linked to the development of anogenital and head and neck cancers. The expression of the viral E6 and E7 genes is crucial for the transforming activities of HPVs. There is accumulating evidence that the HPV E6/E7 oncogenes can profoundly affect the cellular microRNA (miRNA) composition. Since alterations of miRNA expression levels can contribute to cancer development and maintenance, it will be important to understand in depth the crosstalk between the HPV oncogenes and the cellular miRNA network. Here, we describe a method to identify E6/E7-dependent intracellular miRNAs by small RNA deep sequencing, upon silencing of endogenous E6/E7 expression in HPV-positive cancer cells in vitro. In addition, we provide a protocol to identify E6/E7-dependent miRNA alterations in exosomes that are secreted by HPV-positive cancer cells in vitro.