"Human Papillomavirus (HPV)"
Human Papillomavirus (HPV) Nazanin Sharifi, Greg Richart Human Papillomavirus (HPV) What is HPV ? Taxonomy Symptoms The HPV genome HPV and Cancer Diagnosis Epidemiology Risk factors Treatment/Current Research Taxonomy Family: Papillomaviridae Genus: Alphapapillomavirus Approximately 70 species (6, 11,16,18,) Betapapillomavirus Approximately 20 species Gammapapillomavirus 7 species Mupapillomavirus 2 species Nupapillomavirus 1 species What is HPV? HPV is a double-stranded DNA virus that is a sexually transmitted disease (STD) Over 100 different strains, more than 30 sexually transmittable Targets: Skin and mucosal membranes Oral mucosa Esophagus Larynx (voice box) Trachea (airway) Conjunctiva of the eye Cervix primarily affected, but also vagina, penis, etc. \ Hand, Feet, Strains 16 and 18 considered “High Risk,” cancer-causing types Strains 6 and 11 considered “High Risk” and responsible for genital warts Symptoms of Infection! Typically, no signs of infection Infections usually transient, but can be carried dormant for days/months/years Genital warts may develop weeks or months after initial infection Genital cancer can result from infection The HPV Genome HPV and Cancer Strains 6, 11, 16, and 18 responsible for 70% of cervical cancer and 90% genital warts Strain 16 prevalent in penile carcinoma Viral genes E6 and E7 are oncogenes E6 subjugates cellular p53 protein E7 subjugates cellular pRB protein p53 and pRB are critical for regulation of cancerous cells Diagnostic tests Pap test should be done approx. 3 years after the onset of sexual activity or earlier Around 55 million Pap tests are performed each year 3.5 million tests show abnormality Pap test should be done once every three years (depending on the test result) The area where the two types of cells reside is where the sample To get a free or low-cost Pap tissue is taken from and sent out test, please call 1800-4- CANCER to have PAP test done As of now, there are no diagnostic tests to be done for men Epidemiology HPV is the most common STD in the US 20 million Americans infected (15% population) Over half infected 15-24 years old Approx. 30% infected with multiple strains 6.2 million new infections each year By age of 50, at least 80% of women will have been infected In 2006, >9,700 women will be diagnosed with cervical cancer and 3,700 will die Risk Factors and Prevention No “cure” for HPV – prevention most effective Regular gynecological exams Frequent, proper screening for cervical cancer Pap Test (Three years after the onset of sexual activity) Colonoscopy Abstinence Use of condoms Risk Factors: “High risk” sexual activity Smoking Co-infections Treatment – HPV Vaccine “Gardasil” vaccine Approved by FDA on June 8, 2006 Protects against HPV strains 6, 11, 16, and 18 Made from non-infectious virus- like particles (VLPs) Advisory Committee on Immunization Practices recommends use of vaccine for females 9-26 years of age Cryosurgery - Freezing off the warts Virus-like particles assembled from L1 protein of HPV16 Treatment – Current Research RNA Interference Targets high-risk HPV strain 16 Inhibits E6 oncogene expression Great potential, but very new (more testing) Blockage of estrogen receptors Estrogen may stimulate HPV oncogene expression Also very new Resources “Doorbar Group: Human Papillomavirus.” National Institute for Medical Research. Online Resource. Accessed December 10, 2006. Available at http://www.nimr.mrc.ac.uk/virology/doorbar/ Human Papillomavirus: HPV Information for Clinicians. Centers for Disease Control and Prevention. Prepared November 2006. PDF available at http://www.cdc.gov/std/hpv/default.htm “Human Papillomavirus (HPV) Infection.” Centers for Disease Control and Prevention. Online Resource. Accessed December 10, 2006. Available at http://www.cdc.gov/std/hpv/default.htm Au WW, Abdou-Salama S, Al-Hendy A. Inhibition of Growth of Cervical Cancer Cells Using a Dominant Negative Estrogen Receptor Gene. Gynecologic Oncology. Nov. 28, 2006. Niu XY, Peng ZL, Duan WQ, Wang H, Wang P. Inhibition of HPV 16 E6 oncogene expression by RNA interference in vitro and in vivo. International Journal of Gynecological Cancer. March-April, 2006. Higgins GD, Davy M, Roder D, Uzelin DM, Phillips GE, Burrell CJ. Increased Age and M ortality Associated with Cervical Carcinomas Negative for Human Papillomavirus RNA. The Lancet. Oct. 12, 1991. Ortiz, Yarissa. High HPV Concentrations Combined with Cigarette Smoking Significantly Raise Risks of Later Cervical Cancer. American Association for Cancer Research. November 17, 2006. Pics Taken From http://www.uiowa.edu/~oprm/AtlasWIN/C/CondylomaClinf.html http://www.thesahara.net/verrucas_plantar_warts.htm