Pathogenic role of exosomes and microRNAs in HPV-mediated inflammation and cervical cancer: A review

Cervical cancer (CC) is the fourth most common cause of cancer death in women. The most important risk factor for the development of CC is cervical infection with human papilloma virus (HPV). Inflammation is a protective strategy that is triggered by the host against pathogens such as viral infections that acts rapidly to activate the innate immune response. Inflammation is beneficial if it is brief and well controlled; however, if the inflammation is excessive or it becomes of chronic duration, it can produce detrimental effects. HPV proteins are involved, both directly and indirectly, in the development of chronic inflammation, which is a causal factor in the development of CC. However, other factors may also have a potential role in stimulating chronic inflammation. MicroRNAs (miRNAs) (a class of noncoding RNAs) are strong regulators of gene expression. They have emerged as key players in several biological processes, including inflammatory pathways. Abnormal expression of miRNAs may be linked to the induction of inflammation that occurs in CC. Exosomes are a subset of extracellular vesicles shed by almost all types of cells, which can function as cargo transfer vehicles. Exosomes contain proteins and genetic material (including miRNAs) derived from their parent cells and can potentially affect recipient cells. Exosomes have recently been recognized to be involved in inflammatory processes and can also affect the immune response. In this review, we discuss the role of HPV proteins, miRNAs and exosomes in the inflammation associated with CC.