Concomitant heterochromatinisation and down-regulation of gene expression unveils epigenetic silencing of RELB in an aggressive subset of chronic lymphocytic leukemia in males

<p>Abstract</p> <p>Background</p> <p>The sensitivity of chronic lymphocytic leukemia (CLL) cells to current treatments, both <it>in vitro </it>and <it>in vivo</it>, relies on their ability to activate apoptotic death. CLL cells resistant to DNA damage-induced apoptosis display deregulation of a specific set of genes.</p> <p>Methods</p> <p>Microarray hybridization (Human GeneChip, Affymetrix), immunofluorescent <it>in situ </it>labeling coupled with video-microscopy recording/analyses, chromatin-immunoprecipitation (ChIP), polymerase chain reactions (PCR), real-time quantitative PCR (RT-QPCR) and bisulfite genome sequencing were the main methods applied. Statistical analyses were performed by applying GCRMA and SAM analysis (microarray data) and Student's t-test or Mann & Whitney's U-test.</p> <p>Results</p> <p>Herein we show that, remarkably, in a resistant male CLL cells the vast majority of genes were down-regulated compared with sensitive cells, whereas this was not the case in cells derived from females. This gene down-regulation was found to be associated with an overall gain of heterochromatin as evidenced by immunofluorescent labeling of heterochromatin protein 1α (HP-1), trimethylated histone 3 lysine 9 (3metH3K9), and 5-methylcytidine (5metC). Notably, 17 genes were found to be commonly deregulated in resistant male and female cell samples. Among these, <it>RELB </it>was identified as a discriminatory candidate gene repressed in the male and upregulated in the female resistant cells.</p> <p>Conclusion</p> <p>The molecular defects in the silencing of <it>RELB </it>involve an increase in H3K9- but not CpG-island methylation in the promoter regions. Increase in acetyl-H3 in resistant female but not male CLL samples as well as a decrease of total cellular level of RelB after an inhibition of histone deacetylase (HDAC) by trichostatin A (TSA), further emphasize the role of epigenetic modifications which could discriminate two CLL subsets. Together, these results highlighted the epigenetic <it>RELB </it>silencing as a new marker of the progressive disease in males.</p

The LPL/ADAM29 expression ratio is a novel prognosis indicator in chronic lymphocytic leukemia

Although the zeta-associated protein of 70 kDa (ZAP-70) is overexpressed in patients with chronic lymphocytic leukemia (CLL) displaying unmutated IGVH genes and poor prognosis, a previous microarray study from our group identified overexpression of LPL and ADAM29 genes among unmutated and mutated CLL, respectively. To assess the prognostic value of these genes, we quantified their expression by real-time quantitative polymerase chain reaction (PCR) in a cohort of 127 patients with CLL and correlated this with clinical outcome, IGVH mutational status, and ZAP-70 protein expression. IGVH mutational status, ZAP-70, and the LPL and ADAM29 mRNA ratios (L/A ratio) were predictive of event-free survival for the whole cohort and for patients with stage A disease. in patients in stage B and C, the L/A ratio was an independent prognostic factor, whereas ZAP-70 did not predict survival. Simultaneous usage of the L/A ratio and ZAP-70 expression allowed an almost perfect (99%) assessment of the IGVH status in the 80% of patients with concordant results (L/A(+), ZAP-70(+) or L/A(-), ZAP-70(-)). LPL and ADAM29 gene expression could also be determined by a simple competitive multiplex reverse transcription PCR assay. Overall, quantification of LPL and ADAM29 gene expression is a strong prognostic indicator in CLL, providing better prognostic assessment than ZAP-70 in advanced stages of the disease.Hop La Pitie Salpetriere, Serv Hematol Biol, F-75013 Paris, FranceInst Pasteur, Unite Immunohematol & Immunopathol, F-75724 Paris, FranceUniversidade Federal de São Paulo, Disciplina Hematol & Hemoterapia, São Paulo, BrazilInst Pasteur, Dept Ecosyst & Epidemiol Malad Infect, Paris, FranceHop La Pitie Salpetriere, Serv Immunol, Paris, FranceInst Pasteur, Ctr Rech Vaccinale & Biomed, Paris, FranceUniversidade Federal de São Paulo, Disciplina Hematol & Hemoterapia, São Paulo, BrazilWeb of Scienc

Molecular Biomarkers for the Diagnosis of Primary Vitreoretinal Lymphoma

Primary vitreoretinal lymphoma (PVRL) or primary intraocular lymphoma, a subtype of primary central nervous system lymphoma, often masquerades as uveitis. The diagnosis of PVRL requires identification of lymphoma cells inside the eye, which is often challenging due to the frequent necrosis and admixing of PVRL cells with reactive lymphocytes. Therefore, detection of immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements provide molecular diagnosis of B- and T-cell lymphoma, respectively. We retrospectively evaluated 208 cases with a clinical diagnosis of masquerade syndrome from 1998 to 2010. In 200 cases with molecular analyses using microdissection and polymerase chain reaction, we found that 110 cases had IgH gene rearrangement, 5 cases had TCR gene rearrangement, and 85 cases were negative for these two gene arrangements. The molecular data corroborated the cytopathological diagnoses of PVRL and uveitis in the majority of cases. Cytokine above the detected levels in the specimens were also measured in 80 of the 208 cases. A ratio of vitreous IL-10 to IL-6 greater than 1, suggesting PVRL, was found in 56/80 cases; 53/56 had the correct diagnosis. A ratio less than 1, suggesting uveitis, was found in 24/80 cases; 17/24 correctly confirmed the diagnosis. Moreover, the molecular data corresponded well with the clinical course of the diseases. The sensitivity and specificity of these molecular biomarkers for the diagnosis of PVRL are higher than 95%

Impact of HIV Infection and Kaposi Sarcoma on Human Herpesvirus-8 Mucosal Replication and Dissemination in Uganda

Kaposi sarcoma (KS) is the leading cause of cancer in Uganda and occurs in people with and without HIV. Human herpesvirus-8 (HHV-8) replication is important both in transmission of HHV-8 and progression to KS. We characterized the sites and frequency of HHV-8 detection in Ugandans with and without HIV and KS.Participants were enrolled into one of four groups on the basis of HIV and KS status (HIV negative/KS negative, HIV positive/KS negative, HIV negative/KS positive, and HIV positive/KS positive). Participants collected oral swabs daily and clinicians collected oral swabs, anogenital swabs, and plasma samples weekly over 4 weeks. HHV-8 DNA at each site was quantified by polymerase chain reaction (PCR).78 participants collected a total of 2063 orals swabs and 358 plasma samples. Of these, 428 (21%) oral swabs and 96 (27%) plasma samples had detectable HHV-8 DNA. HHV-8 was detected more frequently in both the oropharynx of persons with KS (24 (57%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p = 0.002) and the peripheral blood (30 (71%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p<0.001). In a multivariate model, HHV-8 viremia was more frequent among men (IRR = 3.3, 95% CI = 1.7-6.2, p<0.001), persons with KS (IRR = 3.9, 95% CI = 1.7-9.0, p = 0.001) and persons with HIV infection (IRR = 1.7, 95% CI = 1.0-2.7, p = 0.03). Importantly, oral HHV-8 detection predicted the subsequent HHV-8 viremia. HHV-8 viremia was significantly more common when HHV-8 DNA was detected from the oropharynx during the week prior than when oral HHV-8 was not detected (RR = 3.3, 95% CI = 1.8-5.9 p<0.001). Genital HHV-8 detection was rare (9 (3%) of 272 swabs).HHV-8 detection is frequent in the oropharynx and peripheral blood of Ugandans with endemic and epidemic KS. Replication at these sites is highly correlated, and viremia is increased in men and those with HIV. The high incidence of HHV-8 replication at multiple anatomic sites may be an important factor leading to and sustaining the high prevalence of KS in Uganda

Vasculopathie polypoïdale chronique idiopathique (aspects physiopathologiques, épidémiologiques et cliniques)

La Vasculopathie Polypoidale Chronique Idiopathique, anciennement appelée décollements séro-hémorragiques de l'épithélium pigmentaire récidivants de la femme noire, est caractérisée par un réseau vasculaire choroidien anormal avec des terminaisons polypoidales localisées. Il s'agit d'une affection rare affectant préférentiellement les sujets mélanodermes et asiatiques. Sa description complète a été grandement facilitée par l'apport de l'angiographie au vert d'indocyanine. Sa physiopathologie reste tout de même mal connue et fait encore aujourd'hui l'objet de discussions : est-ce un sous-type de Dégénérescence Maculaire Liée à lAge ou une entité clinique à part entière ? Quelles sont ses origines ? Les objectifs de notre étude sont multiples : décrire la sémiologie clinique et angiographique de la Vasculopathie Polypoidale Chronique Idiopathique en Martinique, essayer d'en établir la prévalence et la fréquence sur cette île. Par ailleurs, nous avons tenté d'étayer l'hypothèse physiopathologique génétique en cherchant non seulement à mettre en évidence un foyer endémique de la pathologie sur cette île mais aussi en recherchant une possible association avec les gènes du système Human Leucocyte Antigen. Enfin, nous avons également réalisé des comparaisons entre cette série de patients martiniquais mélanodermes et une série de patients bordelais caucasiens. Ainsi, notre étude conforte une probable implication de facteurs génétiques dans la genèse de la Vasculopathie Polypoidale Chronique Idiopathique par la mise en évidence d'un bassin de popoulation endémique en Martinique, la surreprésentation de certains allèles du système HLA : HLA A2 et B13, 18, HLA B6, 38, 40, 51, 56, 63, 71, 72, et l'existence de cas familiaux de cette chorio-rétinopathie.Idiopathic Polypoidal Choroidal Vasculopathy, formely reported as multiple recurrent serosanguinoeus retinal pigment epithelial detachments in black women, is characterized by an abnormal choroidal vascular network with aneurysmal or polypoidal dilations. This affection is very rare. Individuals of African-American and Asian descents are at risk for developing Idiopathic polypoidal choroidal vasculopathy. Indocyanin green angiography gave the opportunity to improve our knowledge of this condition. But many questions remain unsolved : is it a distinct entity from age macular degeneration ? Where does it come from ? This study has several purposes. First, we described the clinical manifestations, the fluorescin an indocyanine green angiographic findings and the demographic profile of this affection in Martinique. Secondly, we tried to find a genetic component involved in its pathophysiology by searching an endemic area and a link with human leucocyte antigen genes. inally, we further compared this Martinican series and a caucasian series from Bordeaux. Our study highlights the role of genetic components at the origin of Idiopathic Polypoidal Choroidal Vasculopathy. We indeed put into relief an endemic area for this affection in Martinique, a possible link with several alleles of the human leucocyte antigen system and a familial observation of the disease.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

INTERET DU DOSAGE DE L'IL-10 DANS LE DIAGNOSTIC DES LYMPHOMES INTRAOCULAIRES PRIMITIFS (DES BIOL. MED.)

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Apport des dosages des interleukines 10 et 6, de l'interféron-gamma et de l'intérféron gamma inducible protein-10 par cytométrie en flux dans le diagnostic et le suivi des lymphomes intra-oculaires et cérébraux primitifs

PARIS-BIUP (751062107) / SudocSudocFranceF

Place du dosage de l'interleukine-10, de l'interleukine-6, du CD25 soluble, de MIP-1a, de RANTES et de l'interféron-g par cytométrie en flux dans le pronostic des lymphomes intraoculaires primitifs

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF