Covalent Inhibition of the Human Papillomavirus Type 16 E6 Protein Restores p53 and Suppresses HPV-Driven Tumorigenesis

High-risk human papillomavirus (HPV) infections are the etiology of approximately 5% of all cancers worldwide, including cervical, anal, and oropharyngeal malignancies. HPV E6 is a multifunctional oncoprotein that drives tumorigenesis and is best known for bridging the ubiquitin ligase E6AP (UBE3A) and p53 into a complex that leads to proteasome mediated destruction of p53. We developed small molecule inhibitors that covalently bind to cysteine-51 (Cys-51) in HPV16 E6. In HPV16-positive cancer cells, these compounds increase p53 protein levels and activate p53-dependent transcriptional programs associated with apoptosis and senescence, resulting in reduced tumor cell viability. In vivo , E6 inhibition suppresses the growth of human HPV16 expressing cervical and oropharyngeal tumor cell lines in mice. The strategy of targeting a viral oncoprotein with a covalent inhibitor demonstrates a genotype-specific therapeutic strategy for HPV-associated cancers and premalignant infections, addressing a significant unmet need in current treatment options.