Oncogenic viruses
About one cancer in eight worldwide is caused by a virus. HPV, hepatitis B and C, Epstein-Barr, HTLV-1, KSHV and Merkel cell polyomavirus each hijack the same brakes cancer normally has to mutate, which is why vaccines against HPV and HBV are among the most effective anti-cancer drugs ever made.
Direct carcinogens express viral oncoproteins: HPV E6 degrades p53 and E7 inactivates RB (cervical, anal, oropharyngeal; p16 overexpression is the surrogate); EBV LMP1 mimics CD40 to drive NF-κB and EBNA proteins immortalise B cells (nasopharyngeal, Burkitt, Hodgkin, post-transplant lymphoma; plasma EBV DNA is a biomarker); HTLV-1 Tax/HBZ (adult T-cell leukaemia); KSHV vFLIP/vCyclin (Kaposi sarcoma); MCPyV truncated large T antigen (Merkel cell). Indirect carcinogens act via chronic inflammation and regeneration: HBV (also integrates and expresses HBx) and HCV cause cirrhosis and HCC; H. pylori (a bacterium) drives gastric cancer via CagA and inflammation. Virus-driven tumours carry foreign antigens, explaining high immunotherapy response in Merkel cell carcinoma and HPV+ head and neck cancer, and enabling viral-antigen TCR-T and vaccines. Prevention: HPV (Gardasil 9) and HBV vaccination, HCV cure with direct-acting antivirals, H. pylori eradication.
In one picture
A burglar who does not need to pick the locks because he carries a master key: E6 and E7 are keys that open p53 and RB directly, saving the virus the years of mutation a spontaneous cancer needs. The upside is that the burglar's face is on every camera, so the immune system can be taught to spot him.
Diagram
top- HPV vaccination (Gardasil 9) and HBV vaccination prevent the infection; HCV direct-acting antivirals and H. pylori eradication remove the driver
- HPV testing and colposcopy find and excise precursor lesions
- Checkpoint inhibitors work well in Merkel cell (avelumab, retifanlimab) and HPV+ cancers; EBV- and HPV-specific TCR-T and vaccines are in trials
- Plasma EBV DNA screens for nasopharyngeal carcinoma and tracks response
Pages like this
not linked directly; found by shared links- PathwayBasement membrane & tissue barriers
Shares Colposcopy and excisional treatment (LEEP/LLETZ, cone), Cervical precancer (CIN, HSIL/LSIL), HPV & HBV vaccination, Cervical cancer and the tags mechanism, mechanics-atlas.
- PathwayThe cancer-immunity cycle
Shares Antigen presentation & immune editing, PD-L1, PD-1, Pembrolizumab and the tags mechanism, mechanics-atlas.
- PathwayMismatch repair & microsatellite instability
Shares Antigen presentation & immune editing, PD-L1, PD-1, Pembrolizumab and the tags mechanism, mechanics-atlas.
- PathwayT-cell exhaustion
Shares Antigen presentation & immune editing, PD-L1, PD-1, Pembrolizumab and the tags mechanism, mechanics-atlas.
- PathwayThe cell-cycle engine (cyclins & CDKs)
Shares CDK4/6, p53 / RB / cell-cycle checkpoint, TP53 and the tags mechanism, mechanics-atlas.
- PathwayMutagenesis & mutational signatures
Shares HPV & HBV vaccination, PD-1, Pembrolizumab and the tags mechanism, mechanics-atlas.
- PathwayComplement in cancer
Shares Inflammation & NF-κB, PD-1 and the tags mechanism, mechanics-atlas.
- PathwayUbiquitin–proteasome system & protein homeostasis
Shares Inflammation & NF-κB, The p53 network (guardian of the genome) and the tags mechanism, mechanics-atlas.