A 30-year-old woman has a Pap smear showing high-grade squamous intraepithelial lesion (HSIL). Colposcopy-directed biopsy shows CIN 3. The HPV genotypes most commonly implicated and their target in carcinogenesis are:

• A HPV 6 and 11; E6 protein degrading p53
• B HPV 16 and 18; E5 activating EGFR signalling only
• C HPV 31 and 45; L1 protein integrating into the genome
• D HPV 16 and 18; E6 degrading p53 and E7 inactivating Rb ✓

Explanation

High-risk HPV genotypes 16 and 18 account for approximately 70% of cervical cancers. Their oncoproteins E6 and E7 are the key transforming factors: E6 binds p53 and targets it for ubiquitin-proteasome degradation (bypassing G1/S checkpoint); E7 binds and inactivates Rb, releasing E2F transcription factors to drive cell cycle progression. HPV 6 and 11 are low-risk types causing condylomas; E5 upregulates EGFR but is a weaker oncogene; L1 is the major capsid protein used in vaccines.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.