Expression of pRb and p16INK4 in human thymic epithelial tumors in relation to the presence of human polyomavirus 7

Abstract

BackgroundWe have recently reported the presence of the Human polyomavirus 7 (HPyV7) in human thymic epithelial tumors as assessed by diverse molecular techniques. Here we report on the co-expression of p16, retinoblastoma protein (pRb) and phosphorylated retinoblastoma protein (phospho-Rb) in human thymic epithelial tumors in relation to HPyV7.MethodsPRB, phospho-RB and p16 expression was assessed by immuno-histochemistry in 37 thymomas and 2 thymic carcinomas. 17 thymomas (46 %) and 1 thymic carcinoma (50 %) were recently tested positive for HPyV7. In addition, 20 follicular hyperplasias were tested.ResultsExpression of pRb was observed in 35 thymomas (94.6 %), in 16 thymomas (43.2 %) the expression was strong. Phospho-Rb was observed in 31 thymomas (83.8 %). 19 thymomas (51.4 %) showed immunoreactivity for p16 of which 8 thymomas revealed very strong p16 expression. No p16 expression was detected in thymic carcinomas. In addition, no significant correlation between the presence of HPyV7 and pRb-, phospho-Rb- and p16-expression could be established. No correlation between pRb, phospho-Rb, p16 and WHO staging, Masaoka-Koga staging or the presence of MG was found. All 20 follicular hyperplasias showed expression of pRb and less expression of phospho-Rb.ConclusionsAlthough polyomaviruses have been shown to interact with cell cycle proteins no correlation between the presence of HPyV7 and the expression of pRb, phospho-Rb and p16 in human thymic epithelial tumors was observed. In as much HPyV7 contributes to human thymomagenesis remains to be established. Our data indicate pRb, phospho-Rb and p16 expression are rather unlikely to be involved in HPyV7 related thymomagenesis.

Seroprevalence of fourteen human polyomaviruses determined in blood donors

“…Less is known about the incidence of diseases caused by other polyomaviruses, for example trichodysplasia spinulosa caused by the trichodysplasia spinulosa polyomavirus (TSPyV) [ 2 , 12 ]. Karolinska Institute polyomavirus (KIPyV) and Washington University polyomavirus (WUPyV) have been implicated in respiratory disease [ 13 – 15 ], HPyV6 and HPyV7 in dyskeratotic dermatosis, and HPyV7 in thymomagenesis [ 16 – 19 ]. Furthermore, the New Jersey polyomavirus likely caused a unique but severe case of vasculitis resulting in blindness, dermatitis and myositis.…”

Human polyomavirus-7–associated eruption successfully treated with acitretin

“…In addition to MCPyV and TSV, human polyomavirus‐7 (HPyV‐7) also displays epithelial tropism and is a common virus present on and shed from normal adult skin. HPyV‐7 has additionally been identified in human thymic epithelial tumors . Like other HPyVs, asymptomatic low‐level cutaneous shedding of HPyV‐7 can occur with an intact immune system.…”

Seroprevalence of fourteen human polyomaviruses determined in blood donors

“…Less is known about the incidence of diseases caused by other polyomaviruses, for example trichodysplasia spinulosa caused by the trichodysplasia spinulosa polyomavirus (TSPyV) [2,11]. Karolinska Institute polyomavirus (KIPyV) and Washington University polyomavirus (WUPyV) have been implicated in respiratory disease [12–14], HPyV6 and HPyV7 in dyskeratotic dermatosis, and HPyV7 in thymomagenesis [15–18]. Furthermore, the New Jersey polyomavirus likely caused a unique but severe case of vasculitis resulting in blindness, dermatitis and myositis.…”