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 Printable version |
Warts and squamous cell carcinomas in organ transplant patientWarts and squamous cell carcinomas in organ transplant patients: is the human papillomavirus responsible for carcinogenesis? |
European Journal of Dermatology. Volume 7, Number 1, 5-11, January - February 1997, Synthèse
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 Free Article
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Author(s) : Y. Chardonnet, J. Viac, S. Euvrard |
Summary : As a consequence of immunosuppressive treatment, organ transplant recipients are prone to develop warts and skin carcinomas several years after transplantation. The incidence of human papillomavirus (HPV) infection and skin cancers in these patients is also related to factors which include genetic and immunologic host factors, exposure to UV light, viral and cellular oncogenes and deregulation of transcription factors. Among viral infections of the epidermis, HPVs are widespread in transplant recipients. Several types may be detected in wart lesions and skin carcinomas including benign types 1, 2 or 4, a series of EV-associated HPV types (5/8) and benign or potentially oncogenic mucosal types (6/11 and 16, 18, 35 respectively). The increased susceptibility of transplant recipients to develop skin tumors may be in part attributed to a defect of the local skin immunity with modifications of the epidermal microenvironment under viral infection. UV irradiation represents an additional deleterious factor of paramount importance by increasing immunosuppression and by causing DNA damage. The cooperation of HPV oncogenes E6 and E7 with tumor suppressor genes, p53 and pRB, involved in the cell transformation of genital cancer is less evident in transplant lesions but may contribute to deregulate the cell cycle. Transcription factors (mainly NFkB, E2F and AP-1) activated under cyclosporin A and UVB irradiation, together with growth factors, may also interact to induce keratinocyte activation leading to neoplastic cells. All these factors could be involved in the tumor escaping the immunosurveillance mechanisms which are present under normal conditions and which are drastically altered in grafted patients. It is likely that persistent HPV infection could play a role in the initiation of keratinocyte deregulation and instability leading to hyperproliferation and cell activation leading further to malignancy |
Keywords : human papillomavirus, HPV, organ transplant recipients, squamous cell carcinoma, immunosuppressive treatment, UV irradiation. |
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