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Dive into the research topics where Mohammad Arafa is active.

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Featured researches published by Mohammad Arafa.


International Journal of Oncology | 2011

High incidence of high-risk HPV in benign and malignant lesions of the larynx

Anaelle Duray; Géraldine Descamps; Mohammad Arafa; Christine Decaestecker; Myriam Remmelink; Nicolas Sirtaine; Perle Ernoux-Neufcoeur; Eugene Mutijima; Joan Somja; Christophe Depuydt; Philippe Delvenne; Sven Saussez

The aim of this study was to determine the prevalence of human papillomavirus (HPV) in patients with laryngeal benign lesions (LBLs) and laryngeal squamous cell carcinomas (LSCCs) using a sensitive E6/E7 type-specific PCR. Paraffin-embedded samples from LBL (n=39) and LSCC patients (n=67) were evaluated for the presence of HPV DNA by GP5+/GP6+ consensus PCR and E6/E7 type-specific PCR for HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68. In LSCCs, immunohistochemical staining of p16, p53 and EGFR was also assessed. The E6/E7 type-specific PCR showed that 44 out of 59 LSCC patients (i.e., 75%) had high-risk (hr) HPV types and that 27 out of 35 LBL patients (i.e., 77%) had hrHPV types. HPV-16 viral load was significantly higher in LSCC than in LBL patients (p<10-6). The presence of hrHPV DNA did not correlate with the proportion of disease-free patients. Comparable levels of p16, p53 and EGFR expression were observed in the hrHPV+ tumor group (100% p16+, 56% p53+ and 97% EGFR+) and in the HPV- or low-risk (lr) HPV+ tumor group (92% p16+, 66% p53+ and 100% EGFR+). A very high prevalence of oncogenic HPV-16 was found in a series of benign and malignant laryngeal lesions. LSCC appears to be characterized by an active hrHPV infection. In LSCCs, the hrHPV+ subgroup had a similar prognosis (in terms of risk of recurrence) as the HPV- subgroup.


Cancer Immunology, Immunotherapy | 2009

High expression of PGE2 enzymatic pathways in cervical (pre)neoplastic lesions and functional consequences for antigen-presenting cells

Michael Herfs; Ludivine Herman; Pascale Hubert; Frédéric Minner; Mohammad Arafa; Patrick Roncarati; Yves Henrotin; Jacques Boniver; Philippe Delvenne

Although human papillomavirus (HPV) DNA is detected in the majority of squamous intraepithelial lesions (SIL) and carcinoma (SCC) of the uterine cervix, the persistence or progression of cervical lesions suggest that viral antigens are not adequately presented to the immune system. This hypothesis is reinforced by the observation that most SIL show quantitative and functional alterations of Langerhans cells (LC). The aim of this study was to determine whether prostaglandins (PG) may affect LC density in the cervical (pre)neoplastic epithelium. We first demonstrated that the epithelial expression of PGE2 enzymatic pathways, including cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase 1 (mPGES-1), is higher in SIL and SCC compared to the normal exocervical epithelium and inversely correlated to the density of CD1a-positive LC. By using cell migration assays, we next showed that the motility of immature dendritic cells (DC) and DC partially differentiated in vitro in the presence of PGE2 are differentially affected by PGE2. Immature DC had a lower ability to migrate in the presence of PGE2 compared to DC generated in vitro in the presence of PGE2. Finally, we showed that PGE2 induced a cytokine production profile and phenotypical features of tolerogenic DC, suggesting that the altered expression of PGE2 enzymatic pathways may promote the cervical carcinogenesis by favouring (pre)cancer immunotolerance.


BMC Cancer | 2008

Cervix carcinoma is associated with an up-regulation and nuclear localization of the dual-specificity protein phosphatase VHR

Rachel Henkens; Philippe Delvenne; Mohammad Arafa; Michel Moutschen; Mustapha Zeddou; Lutz Tautz; Jacques Boniver; Tomas Mustelin; Souad Rahmouni

BackgroundThe 21-kDa Vaccinia virus VH1-related (VHR) dual-specific protein phosphatase (encoded by the DUSP3 gene) plays a critical role in cell cycle progression and is itself regulated during the cell cycle. We have previously demonstrated using RNA interference that cells lacking VHR arrest in the G1 and G2 phases of the cell cycle and show signs of beginning of cell senescence.MethodsIn this report, we evaluated successfully the expression levels of VHR protein in 62 hysterectomy or conization specimens showing the various (pre) neoplastic cervical epithelial lesions and 35 additional cases of hysterectomy performed for non-cervical pathologies, from patients under 50 years of age. We used a tissue microarray and IHC technique to evaluate the expression of the VHR phosphatase. Immunofluorescence staining under confocal microscopy, Western blotting and RT-PCR methods were used to investigate the localization and expression levels of VHR.ResultsWe report that VHR is upregulated in (pre) neoplastic lesions (squamous intraepithelial lesions; SILs) of the uterine cervix mainly in high grade SIL (H-SIL) compared to normal exocervix. In the invasive cancer, VHR is also highly expressed with nuclear localization in the majority of cells compared to normal tissue where VHR is always in the cytoplasm. We also report that this phosphatase is highly expressed in several cervix cancer cell lines such as HeLa, SiHa, CaSki, C33 and HT3 compared to primary keratinocytes. The immunofluorescence technique under confocal microscopy shows that VHR has a cytoplasmic localization in primary keratinocytes, while it localizes in both cytoplasm and nucleus of the cancer cell lines investigated. We report that the up-regulation of this phosphatase is mainly due to its post-translational stabilization in the cancer cell lines compared to primary keratinocytes rather than increases in the transcription of DUSP3 locus.ConclusionThese results together suggest that VHR can be considered as a new marker for cancer progression in cervix carcinoma and potential new target for anticancer therapy.


Histopathology | 2008

High frequency of RASSF1A and RARb2 gene promoter methylation in morphologically normal endometrium adjacent to endometrioid adenocarcinoma

Mohammad Arafa; Frédéric Kridelka; Valérie Mathias; Jean-François Vanbellinghen; Isabelle Renard; Jean-Michel Foidart; Jacques Boniver; Philippe Delvenne

Aims:  To identify a DNA methylation signature of endometrioid carcinoma of the endometrium (EEC) in the early stages of endometrial carcinogenesis.


Bulletin Du Cancer | 2009

Implication des papillomavirus humains dans Les cancers des voies aérodigestives supérieures

P. E. Neufcoeur; Mohammad Arafa; Philippe Delvenne; Sven Saussez

Human papillomavirus (HPV) is one of the most common causes of sexually transmitted infection in the world. France and Belgium present one of the highest incidence of head and neck squamous cell carcinomas (HNSCC) worldwide. Besides, considering only the male population, HNSCCs represent the fourth most frequent cancer after prostate, lung and colon cancers. Although the causal link between high-risk HPVs and cervical carcinoma is well established, the implication of this viral infection in HNSCC remains debatable. Here, we discuss current knowledge concerning the HPV implication in HNSCCs. Based on our literature review, 20 to 25% of HNSCCs could be associated with oncogenic HPVs, in particular HPV type 16. The oropharynx--more precisely the tonsil--is the head and neck location presenting the highest incidence of HPV infection. Moreover, a clear increase of tonsillar carcinoma incidence has been described. As observed in cervical carcinomas, HPV positive HNSCCs are sexually transmitted and characterized by alterations of p53 and pRb signalling pathways. Several studies have shown that HPV positive subgroup presented better prognosis particularly if these patients overexpressed p16INK4. New studies regarding HPV status in HNSCCs are warranted to provide a rationale for large scale HPV vaccination in young male populations.


Applied Immunohistochemistry & Molecular Morphology | 2008

Detection of HPV-induced cervical (pre) neoplastic lesions: a tissue microarray (TMA) study.

Mohammad Arafa; Jacques Boniver; Philippe Delvenne

The aim of this study was to evaluate the usefulness of a panel of biomarkers in the characterization of human papillomavirus (HPV)-induced cervical lesions. Management of these lesions depends on their histologic confirmation. Misinterpretation especially for benign mimics results in a significant diagnostic disagreement. For these reasons, a continuous effort is still needed to discover surrogate markers, which could support the final diagnosis. Archival biopsies of normal ectocervical and endocervical tissues, squamous metaplasia, cervical intraepithelial neoplasia (CIN), squamous cell carcinoma, adenocarcinoma in situ, and adenocarcinoma were retrieved to perform a tissue microarray (TMA). A panel of markers was tested on the TMA obtained slides by in situ hybridization (HPV DNA) and immunohistochemistry (p16, involucrin, Ki-67, and HPV L1 proteins). The sensitivity to detect high-risk HPV DNA increased with lesions severity. In situ hybridization signals suggesting integrated viral physical status predominated in CIN II/III, squamous cell carcinoma, and glandular (pre) neoplastic lesions. The p16 and Ki-67 protein expression increased from CIN I to CIN III and to infiltrative lesions. Involucrin positivity was better appreciated in well-differentiated diagnostic entities (ectocervix, mature metaplasia, and CIN I). HPV L1 antibody detected the viral capsid protein in a low proportion of CIN I and II. In conclusion, using a panel of cervical biomarkers improves the final reporting of various HPV-induced epithelial lesions. Carefully constructed TMA with single spots of 1-mm diameter are powerful tools, which have a high reliability in representing full tissue sections.


Pathology | 2010

Current concepts in the pathology and epigenetics of endometrial carcinoma

Mohammad Arafa; Joan Somja; Pierre Dehan; Frédéric Kridelka; Frédéric Goffin; Jacques Boniver; Philippe Delvenne

In the Western world, endometrial carcinoma is the most common malignant tumour of the female genital tract and is the fourth most common cancer in women. Two different clinicopathological subtypes are recognised: the oestrogen-related (type I, endometrioid) and the non-oestrogen related (type II, non-endometrioid). This article reviews the epidemiology, risk factors, genetic alterations during endometrial carcinogenesis, features of tumours and precursors and early detection of the disease. Insights into the epigenetic alterations, with emphasis on DNA methylation during endometrial carcinogenesis, and their diagnostic value are also provided.


International Journal of Cancer | 2016

Myoferlin plays a key role in VEGFA secretion and impacts tumor‐associated angiogenesis in human pancreas cancer

Karim Fahmy; Arnaud Gonzalez; Mohammad Arafa; Paul Peixoto; Akeila Bellahcene; Andrei Turtoi; Philippe Delvenne; Marc Thiry; Vincenzo Castronovo; Olivier Peulen

Pancreatic ductal adenocarcinoma is one of the most deadly forms of cancers with no satisfactory treatment to date. Recent studies have identified myoferlin, a ferlin family member, in human pancreas adenocarcinoma where its expression was associated to a bad prognosis. However, the function of myoferlin in pancreas adenocarcinoma has not been reported. In other cell types, myoferlin is involved in several key plasma membrane processes such as fusion, repair, endocytosis and tyrosine kinase receptor activity. In this study, we showed that myoferlin silencing in BxPC‐3 human pancreatic cancer cells resulted in the inhibition of cell proliferation in vitro and in a significant reduction of the tumor volume in chick chorioallantoic membrane assay. In addition to be smaller, the tumors formed by the myoferlin‐silenced cells showed a marked absence of functional blood vessels. We further demonstrated that this effect was due, at least in part, to an inhibition of VEGFA secretion by BxPC‐3 myoferlin‐silenced cells. Using immunofluorescence and electron microscopy, we linked the decreased VEGFA secretion to an impairment of VEGFA exocytosis. The clinical relevance of our results was further strengthened by a significant correlation between myoferlin expression in a series of human pancreatic malignant lesions and their angiogenic status evaluated by the determination of the blood vessel density.


Journal of Biological Chemistry | 2013

Novel Association between Vasoactive Intestinal Peptide and CRTH2 Receptor in Recruiting Eosinophils A POSSIBLE BIOCHEMICAL MECHANISM FOR ALLERGIC EOSINOPHILIC INFLAMMATION OF THE AIRWAYS

Amr E. El-Shazly; Dominique Begon; Gaelle Kustermans; Mohammad Arafa; Estelle Dortu; Monique Henket; Philippe P. Lefebvre; Renaud Louis; Philippe Delvenne

Background: Ligand receptor ligation regulates immune-inflammatory cell chemotaxis. Results: Vasoactive intestinal peptide and prostaglandin D2 share the CRTH2 receptor in inducing eosinophil chemotaxis. Conclusion: There is a strong association between VIP and CRTH2 in eosinophil chemotaxis. Significance: This is the first evidence that may indicate that CRTH2 could modulate the neuroimmunoregulatory axis in allergic eosinophil inflammation. We explored the relation between vasoactive intestinal peptide (VIP), CRTH2, and eosinophil recruitment. It is shown that CRTH2 expression by eosinophils from allergic rhinitis (AR) patients and eosinophil cell line (Eol-1 cells) was up-regulated by VIP treatment. This was functional and resulted in exaggerated migratory response of cells against PGD2. Nasal challenge of AR patients resulted in a significant increase of VIP contents in nasal secretion (ELISA), and the immunohistochemical studies of allergic nasal tissues showed significant expression of VIP in association with intense eosinophil recruitment. Biochemical assays showed that VIP-induced eosinophil chemotaxis from AR patients and Eol-1 cells was mediated through the CRTH2 receptor. Cell migration against VIP was sensitive to protein kinase C (PKC) and protein kinase A (PKA) inhibition but not to tyrosine kinase or p38 MAPK inhibition or calcium chelation. Western blot demonstrated a novel CRTH2-mediated cytosol-to-membrane translocation of PKC-ϵ, PKC-δ, and PKA-α, -γ, and -IIαreg in Eol-1 cells upon stimulation with VIP. Confocal images and FACS demonstrated a strong association and co-localization between VIP peptide and CRTH2 molecules. Further, VIP induced PGD2 secretion from eosinophils. Our results demonstrate the first evidence of association between VIP and CRTH2 in recruiting eosinophils.


Head & Neck Oncology | 2012

Metastatic rhabdomyosarcoma of the thyroid gland, a case report

Mohamed T Hafez; Mohamed Hegazy; Khaled Abd Elwahab; Mohammad Arafa; Islam Abdou; Basel Refky

The thyroid gland is a known but an unusual site for metastatic tumors from various primary sites. Despite the fact that it is one of the largest vascular organs in the body, clinical and surgical cases have given an incidence of 3 % of secondary malignances of the organ. Nevertheless, thyroid metastases are not an exceptional finding at autopsy, they are encountered in 2 % to 24 % of the patients with malignant neoplasm.Soft tissue sarcomas metastatic to the thyroid are extremely rare as the majority of thyroid metastasis are caused by tumors of the kidneys, lungs, mammary glands, ovaries , and colon or by melanomas.We report a case of 22-years-old woman with right leg rhabdomyosarcoma metastatic to the thyroid gland.

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