miRNA as viral transcription tuners in HPV-mediated cervical carcinogenesis

High-risk human papillomaviruses (HPVs) are oncogenic DNA viruses that promote carcinogenic signaling by their oncoproteins mainly E6 and E7. A well-defined promoter regulates expression and enhancer region on HPV genome containing number of cis elements that essentially require a set of cognate host transcription factors to regulate viral promoter gene activity. Expression of these host factors is tightly regulated at multiple levels such as transcriptional, post-transcriptional and post-translational level. Discovery of microRNAs (miRs) in recent years and differential expression of a set of specific miRs in HPV infection and cervical lesions indicate that among various regulatory mechanisms, role of these differentially expressed miRs in the post-transcriptional control is pivotal. Present review analyses and attempts to compile currently available miR data related to HPV infection and cervical carcinogenesis with a special focus on miRs that may regulate expression of the host and viral factors particularly responsible for viral transcription leading to carcinogenic progression of the lesion. Further, the review attempts to assess the therapeutic potential of miR-based strategies in therapeutic targeting of HPV infection during cervical carcinogenesis.