Human papillomavirus type 16 E6 oncoprotein and Human papillomavirus type 16 E7 oncoprotein (HPV16 E6 (for E6 protein), HPV16 E7 (for E7 protein))

The Human papillomavirus type 16 E6 and E7 oncoproteins are the principal viral proteins responsible for transforming host cells and driving HPV-associated cancers, most notably cervical cancer[5][7][8]. E6 promotes the degradation of the tumor suppressor p53 through direct interaction with the cellular E6-AP ubiquitin ligase, resulting in impaired apoptosis, deregulated cell cycle, and loss of genomic integrity[5][7][8]. E7 binds and inactivates the retinoblastoma protein (pRb) and related pocket proteins, releasing E2F transcription factors to force cell cycle progression and proliferation, even in differentiating epithelium or in the presence of DNA damage[8][9]. Collectively, their cooperative activity leads to immortalization, loss of growth control, cellular transformation, and the acquisition of all canonical hallmarks of cancer cells[7][8]. E6 and E7 disrupt multiple cellular processes including cell adhesion, polarity (via targeting PDZ domain–containing proteins), cell migration, and regulation of apoptosis, and are absolutely required for the maintenance and progression of HPV-induced malignancy[4][5][7]. Due to their indispensable role in HPV-driven tumorigenesis, they are considered premier therapeutic targets for anti-HPV strategies, with both protein- and nucleic acid-based inhibitors under investigation. No direct small molecule drugs are currently available, but various therapeutic vaccines and inhibitory RNAs are in development.

Other names

HPV-16 E6 proteinHPV-16 E7 proteinHPV16 early protein 6HPV16 early protein 7HPV E6/E7 oncoproteins

Inhibition/degradation of tumor suppressor proteins (p53 by E6, pRb by E7); Promotion of cell cycle progression (E7 disrupts pRb-E2F complex, freeing E2F); Evasion of apoptosis (E6 mediates p53 degradation via E6-AP ubiquitin ligase); Induction of genomic instability