583 research outputs found

    Human papillomavirus-associated increase in p16INK4A expression in penile lichen sclerosus and squamous cell carcinoma

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    Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2·5, which does not permit commercial exploitationBackground: Human papillomaviruses (HPVs) are sexually transmitted human carcinogens that may play a role in the oncogenesis of penile cancer. Objectives: To investigate the role of HPV infection and expression of the tumour suppressor protein p16INK4A in the pathogenesis of penile cancer. Methods: By means of polymerase chain reaction amplification and reverse hybridization line probe assay to detect HPV infection, and immunohistochemical staining for p16INK4A and Ki67, we analysed 26 penile squamous cell carcinomas (SCCs) and 20 independent penile lichen sclerosus (LS) lesions from 46 patients. Results: HPV DNA was found in 54% of penile SCCs and 33% of penile LS cases in single and multiple infections. High-risk HPV 16 was the predominant HPV type detected. No relationship between Ki67 expression and HPV infection was observed. Strong immunostaining for p16INK4A correlated with HPV 16/18 infection in both penile LS and penile SCC. In our penile SCC series the cancer margins were also associated with penile LS in 13 of 26 lesions, and HPV was detected in seven of the 13 SCC cases associated with LS and in six of the 11 SCC lesions not involving LS. Conclusions: Our study shows a high prevalence of HPV 16 and p16INK4A expression in penile lesions, consistent with an active role for HPV in interfering with the retinoblastoma pathway. High-risk HPV infection could be involved in the tumorigenic process in 50% of penile cancers, and the use of prophylactic HPV vaccines has the potential to prevent these cancers.Peer reviewedFinal Published versio

    Multifocal Aggressive Squamous Cell Carcinomas Induced by Prolonged Voriconazole Therapy: A Case Report

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    Voriconazole is a treatment for severe fungal infections. Prolonged voriconazole therapy may induce skin reactions, with 1% of severe photosensitivity accidents. Recently the imputability of voriconazole in skin carcinogenesis has been suggested. This report concerns a 55-year-old man suffering from pulmonary aspergillosis who presented a phototoxic reaction a few months after introduction of voriconazole, followed by multiple squamous cell carcinomas of sun-exposed skin areas. After voriconazole discontinuation, no new carcinoma was observed. The detection of EBV and HPV in skin lesions was negative. Exploration of gene mutations involved in skin carcinogenesis showed two variants of the MICR gene. The occurrence of multiple, recurrent, aggressive squamous cell carcinomas is rare with voriconazole, but its imputability is strongly suggested. A plausible hypothesis is that several factors including voriconazole uptake, immunosuppression, and genetic background could explain the phenotype of fast-developing skin carcinomas. Voriconazole therapy should be accompanied by stringent photoprotection and skin monitoring

    Expanding the clinical spectrum of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis due to <i>FAM111B </i>mutations

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    BACKGROUND: Hereditary Fibrosing Poikiloderma (HFP) with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP [MIM 615704]) is a very recently described entity of syndromic inherited poikiloderma. Previously by using whole exome sequencing in five families, we identified the causative gene, FAM111B (NM_198947.3), the function of which is still unknown. Our objective in this study was to better define the specific features of POIKTMP through a larger series of patients. METHODS: Clinical and molecular data of two families and eight independent sporadic cases, including six new cases, were collected. RESULTS: Key features consist of: (i) early-onset poikiloderma, hypotrichosis and hypohidrosis; (ii) multiple contractures, in particular triceps surae muscle contractures; (iii) diffuse progressive muscular weakness; (iv) pulmonary fibrosis in adulthood and (v) other features including exocrine pancreatic insufficiency, liver impairment and growth retardation. Muscle magnetic resonance imaging was informative and showed muscle atrophy and fatty infiltration. Histological examination of skeletal muscle revealed extensive fibroadipose tissue infiltration. Microscopy of the skin showed a scleroderma-like aspect with fibrosis and alterations of the elastic network. FAM111B gene analysis identified five different missense variants (two recurrent mutations were found respectively in three and four independent families). All the mutations were predicted to localize in the trypsin-like cysteine/serine peptidase domain of the protein. We suggest gain-of-function or dominant-negative mutations resulting in FAM111B enzymatic activity changes. CONCLUSIONS: HFP with tendon contractures, myopathy and pulmonary fibrosis, is a multisystemic disorder due to autosomal dominant FAM111B mutations. Future functional studies will help in understanding the specific pathological process of this fibrosing disorder

    Inhibition of the Proprotein Convertases Represses the Invasiveness of Human Primary Melanoma Cells with Altered p53, CDKN2A and N-Ras Genes

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    Altered tumor suppressor p53 and/or CDKN2A as well as Ras genes are frequently found in primary and metastatic melanomas. These alterations were found to be responsible for acquisition of invasive and metastatic potential through their defective regulatory control of metalloproteinases and urokinase genes.Using primary human melanoma M10 cells with altered p53, CDKN2A and N-Ras genes, we found that inhibition of the proprotein convertases (PCs), enzymes involved in the proteolytic activation of various cancer-related protein precursors resulted in significantly reduced invasiveness. Analysis of M10 cells and their gastric and lymph node derived metastatic cells revealed the presence of all the PCs found in the secretory pathway. Expression of the general PCs inhibitor alpha1-PDX in these cells in a stable manner (M10/PDX) had no effect on the mRNA expression levels of these PCs. Whereas, in vitro digestion assays and cell transfection experiments, revealed that M10/PDX cells display reduced PCs activity and are unable to process the PCs substrates proIGF-1R and proPDGF-A. These cells showed reduced migration and invasion that paralleled decreased gelatinase MMP-2 activity and increased expression and secretion of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. Furthermore, these cells showed decreased levels of urokinase-type plasminogen activator receptor (uPAR) and increased levels of plasminogen activator inhibitor-1 (PAI-1).Taken together, these data suggest that inhibition of PCs activity results in decreased invasiveness of primary human melanoma cells despite their altered p53, CDKN2A and N-Ras genes, suggesting that PCs may serve as novel therapeutic targets in melanoma

    Vismodegib resistant mutations are not selected in multifocal relapses of locally advanced basal cell carcinoma after vismodegib discontinuation.

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    Hedgehog pathway inhibitors (HPI) inactivating SMO 1, have become first line treatment for patients with locally advanced BCC (laBCC). HPI safety and efficacy have been shown in clinical trials2,3. Nevertheless, common adverse events lead to treatment discontinuation

    Individuals with presumably hereditary uveal melanoma do not harbour germline mutations in the coding regions of either the P16INK4A, P14ARF or cdk4 genes

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    In familial cutaneous malignant melanoma (CMM), disruption of the retinoblastoma (pRB) pathway frequently occurs through inactivating mutations in the p16 (p16INK4A/CDKN2A/MTS1) gene or activating mutations in the G1-specific cyclin dependent kinase 4 gene (CDK4). Uveal malignant melanoma (UMM) also occurs in a familial setting, or sometimes in association with familial or sporadic CMM. Molecular studies of sporadic UMM have revealed somatic deletions covering the INK4A-ARF locus (encoding P16INK4Aand P14ARF) in a large proportion of tumours. We hypothesized that germline mutations in the p16INK4A, p14ARFor CDK4 genes might contribute to some cases of familial UMM, or to some cases of UMM associated with another melanoma. Out of 155 patients treated at the Institut Curie for UMM between 1994 and 1997, and interviewed about their personal and familial history of melanoma, we identified seven patients with a relative affected with UMM (n = 6) or CMM (n = 1), and two patients who have had, in addition to UMM, a personal history of second melanoma, UMM (n = 1), or CMM (n = 1). We screened by polymerase chain reaction single-strand conformation polymorphism the entire coding sequence of the INK4A-ARF locus (exon 1α from p16INK4A, exon 1β from p14ARF, and exons 2 and 3, common to both genes), as well as the exons 2, 5 and 8 of the CDK4 gene, coding for the functional domains involved in p16 and/or cyclin D1 binding. A previously reported polymorphism in exon 3 of the INK4A-ARF locus was found in one patient affected with bilateral UMM, but no germline mutations were detected, either in the p16INK4A, p14ARFor CDK4 genes. Our data support the involvement of other genes in predisposition to uveal melanoma. © 2000 Cancer Research Campaig

    Concomitant Xeroderma pigmentosum and disseminated small plaque psoriasis: first case of an antinomic association

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    We present the case of an eighteen-year-old Caucasian white boy who was diagnosed with xeroderma pigmentosum type A at age 5 and who experienced over the past year disseminated small plaque psoriasis confirmed with skin punch biopsy. The psoriatic lesions were successfully treated with multipotent topical corticosteroids and systemic retinoids. To our knowledge, the association between psoriasis and xeroderma pigmentosum has not been previously reported and may be regarded as unlikely when considering the pathogenesis of both diseases

    p16INK4a-induced senescence is disabled by melanoma-associated mutations

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    The p16INK4a-Rb tumour suppressor pathway is required for the initiation and maintenance of cellular senescence, a state of permanent growth arrest that acts as a natural barrier against cancer progression. Senescence can be overcome if the pathway is not fully engaged, and this may occur when p16INK4a is inactivated. p16INK4a is frequently altered in human cancer and germline mutations affecting p16INK4a have been linked to melanoma susceptibility. To characterize the functions of melanoma-associated p16INK4a mutations, in terms of promoting proliferative arrest and initiating senescence, we utilized an inducible expression system in a melanoma cell model. We show that wild-type p16INK4a promotes rapid cell cycle arrest that leads to a senescence programme characterized by the appearance of chromatin foci, activation of acidic β-galactosidase activity, p53 independence and Rb dependence. Accumulation of wild-type p16INK4a also promoted cell enlargement and extensive vacuolization independent of Rb status. In contrast, the highly penetrant p16INK4a variants, R24P and A36P failed to arrest cell proliferation and did not initiate senescence. We also show that overexpression of CDK4, or its homologue CDK6, but not the downstream kinase, CDK2, inhibited the ability of wild-type p16INK4a to promote cell cycle arrest and senescence. Our data provide the first evidence that p16INK4a can initiate a CDK4/6-dependent autonomous senescence programme that is disabled by inherited melanoma-associated mutations

    Divergence between the high rate of p53 mutations in skin carcinomas and the low prevalence of anti-p53 antibodies

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    Circulating anti-p53 antibodies have been described and used as tumoural markers in patients with various cancers and strongly correlate with the p53 mutated status of the tumours. No study has yet looked at the prevalence of such antibodies in skin carcinoma patients although these tumours have been shown to be frequently p53 mutated. Most skin carcinoma can be diagnosed by examination or biopsy, but aggressive, recurrent and/or non-surgical cases' follow up would be helped by a biological marker of residual disease. We performed a prospective study looking at the prevalence of anti-p53 antibodies using an ELISA technique in a series of 105 skin carcinoma patients in comparison with a sex- and age-matched control skin carcinoma-free group (n = 130). Additionally, p53 accumulation was studied by immunohistochemistry to confirm p53 protein altered expression in a sample of tumours. Anti-p53 antibodies were detected in 2.9% of the cases, with a higher prevalence in patients suffering from the more aggressive squamous cell type (SCC) of skin carcinoma (8%) than for the more common and slowly growing basal cell carcinoma type or BCC (1.5%). p53 protein stabilization could be confirmed in 80% of tumours studied by IHC. This low level of anti-p53 antibody detection contrasts with the high rate of p53 mutations reported in these tumours. This observation shows that the anti-p53 humoral response is a complex and tissue-specific mechanism. © 2001 Cancer Research Campaign http://www.bjcancer.co
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