Elena Netchiporouk
McGill University
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Publication
Featured researches published by Elena Netchiporouk.
Cell Cycle | 2014
Elena Netchiporouk; Ivan V. Litvinov; Linda Moreau; Martin Gilbert; Denis Sasseville; Madeleine Duvic
Deregulation of STAT signaling has been implicated in the pathogenesis for a variety of cancers, including CTCL. Constitutive activation of STAT5 and STAT3 was observed in early and late stages of CTCL, respectively. In early stages, IL-2, IL-7 and IL-15 signaling via JAK1 and JAK3 kinases is believed to be responsible for activating STAT5, while in advanced stages development of IL-21 autocrine signaling is thought to be important for STAT3 activation. Recent molecular evidence further suggests that upregulation of STAT5 in early disease stages results in increased expression of oncogenic miR-155 microRNA that subsequently targets STAT4 expression on mRNA level. STAT4 signaling is known to be critical for T helper (Th) 1 phenotype differentiation and its loss results in a switch from Th1 to Th2 phenotype in malignant T cells. During this switch the expression of STAT6 is often upregulated in CTCL. In advanced stages, activation of STAT3 and STAT5 may become completely cytokine-independent and be driven only via constitutively active JAK1 and JAK3 kinases. Further research into the molecular pathogenesis of JAK/STAT signaling in this cancer may enable us to develop effective therapies for our patients.
Clinical Cancer Research | 2015
Ivan V. Litvinov; Elena Netchiporouk; Brendan Cordeiro; Marc-André Doré; Linda Moreau; Kevin Pehr; Martin Gilbert; Youwen Zhou; Denis Sasseville; Thomas S. Kupper
Purpose: Although many patients with mycosis fungoides presenting with stage I disease enjoy an indolent disease course and normal life expectancy, about 15% to 20% of them progress to higher stages and most ultimately succumb to their disease. Currently, it is not possible to predict which patients will progress and which patients will have a stable disease. Previously, we conducted microarray analyses with RT-PCR validation of gene expression in biopsy specimens from 60 patients with stage I–IV cutaneous T-cell lymphoma (CTCL), identified three distinct clusters based upon transcription profile, and correlated our molecular findings with 6 years of clinical follow-up. Experimental Design: We test by RT-PCR within our prediction model the expression of about 240 genes that were previously reported to play an important role in CTCL carcinogenesis. We further extend the clinical follow-up of our patients to 11 years. We compare the expression of selected genes between mycosis fungoides/Sézary syndrome and benign inflammatory dermatoses that often mimic this cancer. Results: Our findings demonstrate that 52 of the about 240 genes can be classified into cluster 1–3 expression patterns and such expression is consistent with their suggested biologic roles. Moreover, we determined that 17 genes (CCL18, CCL26, FYB, T3JAM, MMP12, LEF1, LCK, ITK, GNLY, IL2RA, IL26, IL22, CCR4, GTSF1, SYCP1, STAT5A, and TOX) are able to both identify patients who are at risk of progression and also distinguish mycosis fungoides/Sézary syndrome from benign mimickers. Conclusions: This study, combined with other gene expression analyses, prepares the foundation for the development of personalized molecular approach toward diagnosis and treatment of CTCL. Clin Cancer Res; 21(12); 2820–9. ©2015 AACR.
Cancer Medicine | 2015
Ivan V. Litvinov; Michael T. Tetzlaff; Elham Rahme; Michelle A. Jennings; David R. Risser; Pamela Gangar; Elena Netchiporouk; Linda Moreau; Victor G. Prieto; Denis Sasseville; Madeleine Duvic
Cutaneous T‐cell lymohomas (CTCLs) are rare, but potentially devastating malignancies, with Mycosis fungoides and Sézary Syndrome being the most common. In our previous study, we identified and described regions of geographic clustering of CTCL cases in Texas by analyzing ~1990 patients using two distinct cancer registries. In the current work, we describe in detail demographic patterns for this malignancy in our study population and apply logistic regression models to analyze the incidence of CTCL by sex, race, age, and clinical stage at the time of diagnosis. Furthermore, using Fishers exact test, we analyze changes in incidence over time in the identified Houston communities with unusually high CTCL incidence. While CTCL primarily affects Caucasian individuals >55 years old, we confirm that it presents at a younger age and with more advanced disease stages in African‐American and Hispanic individuals. Also, we demonstrate a significant increase in CTCL incidence over time in the identified communities. Spring, Katy, and Houston Memorial areas had high baseline rates. Furthermore, a statistically significant disease surge was observed in these areas after ~2005. This report supplements our initial study documenting the existence of geographic clustering of CTCL cases in Texas and in greater detail describes demographic trends for our patient population. The observed surge in CTCL incidence in the three identified communities further argues that this malignancy may be triggered by one or more external etiologic agents.
OncoImmunology | 2014
Ivan V. Litvinov; Elena Netchiporouk; Brendan Cordeiro; Hanieh Zargham; Kevin Pehr; Martin Gilbert; Youwen Zhou; Linda Moreau; Anders Woetmann; Niels Ødum; Thomas S. Kupper; Denis Sasseville
Cutaneous T-cell lymphoma (CTCL) is a potentially devastating malignancy. The pathogenesis of this cancer remains poorly elucidated. Previous studies focused on analysis of expression and function of known oncogenes and tumor suppressor genes. However, emerging reports highlight that it is also important to analyze the expression of genes that are ectopically expressed in CTCL (e.g., embryonic stem cell genes (ESC), cancer testis (CT) genes, etc.). Currently, it is not known whether ESC genes are expressed in CTCL. In the current work, we analyze by RT-PCR the expression of 26 ESC genes, many of which are known to regulate pluripotency and promote cancer stem cell-like phenotype, in a historic cohort of 60 patients from Boston and in a panel of 11 patient-derived CTCL cell lines and compare such expression to benign inflammatory dermatoses that often clinically mimic CTCL. Our findings document that many critical ESC genes including NANOG, SOX2, OCT4 (POU5F1) and their upstream and downstream signaling members are expressed in CTCL. Similarly, polycomb repressive complex 2 (PRC2) genes (i.e., EZH2, EED, and SUZ12) are also expressed in CTCL lesional skin. Furthermore, select ESC genes (OCT4, EED, TCF3, THAP11, CHD7, TIP60, TRIM28) are preferentially expressed in CTCL samples when compared to benign skin biopsies. Our work suggests that ESC genes are ectopically expressed together with CT genes, thymocyte development genes and B cell-specific genes and may be working in concert to promote tumorigenesis. Specifically, while ESC genes may be promoting cancer stem cell-like phenotype, CT genes may be contributing to aneuploidy and genomic instability by producing aberrant chromosomal translocations. Further analysis of ESC expression and function in this cancer will greatly enhance our fundamental understanding of CTCL and will help us identify novel therapeutic targets.
Pediatric Allergy and Immunology | 2015
Elena Netchiporouk; Christopher H. Nguyen; Thusanth Thuraisingham; Fatemeh Jafarian; Marcus Maurer
anti-IgE antibody (omalizumab) could contribute to a new therapeutic scenario for SU and throw light on the potential pharmacological mechanism of omalizumab in this disease. In fact, it is conceivable that omalizumab, depleting IgE, downregulates mast cell activities and reduces mast cell-dependent inflammatory mechanisms (8). Further studies are needed to identify patients with SU who could be treated earlier and successfully with omalizumab. In addition, randomized controlled trials are awaited to identify both effective treatment schedule(s) and doses for eligible patient suffering from solar urticaria unresponsive to conventional treatment.
OncoImmunology | 2017
Ivan V. Litvinov; Michael T. Tetzlaff; Philippe Thibault; Pamela Gangar; Linda Moreau; Andrew K. Watters; Elena Netchiporouk; Kevin Pehr; Victor G. Prieto; Elham Rahme; Nathalie Provost; Martin Gilbert; Denis Sasseville; Madeleine Duvic
ABSTRACT Cutaneous T-Cell Lymphomas (CTCL) are rare, but potentially devastating malignancies, whose pathogenesis remains poorly elucidated. Unfortunately, currently it is not possible to predict based on the available criteria in which patients the cancer will progress and which patients will experience an indolent disease course. Furthermore, at early stages this malignancy often masquerades as psoriasis, chronic eczema or other benign inflammatory dermatoses. As a result, it takes on average 6 y to diagnose this lymphoma since its initial presentation. In this study, we performed transcription expression profiling using TruSeq targeted RNA gene expression on 181 fresh and formalin-fixed and paraffin-embedded (FFPE) skin samples from CTCL patients and patients affected by benign inflammatory dermatoses that often mimic CTCL clinically and on histology (e.g., psoriasis, chronic eczema, etc.) We also analyzed multiple longitudinal biopsies that were obtained from the same patients over time. Our results underscore significant molecular heterogeneity with respect to gene expression between different patients and even within the same patients over time. Our study also confirmed TOX, FYB, LEF1, CCR4, ITK, EED, POU2AF, IL26, STAT5, BLK, GTSF1 and PSORS1C2 genes as being differentially expressed between CTCL and benign skin biopsies. In addition, we found that differential expression for a subset of these markers (e.g., TOX, FYB, GTSF1 and CCR4) may be useful in prognosticating this disease. This research, combined with other molecular analyses, prepares the foundation for the development of personalized molecular approach toward diagnosis and management of CTCL.
Transplantation Proceedings | 2013
Elena Netchiporouk; J. Tchervenkov; S. Paraskevas; Denis Sasseville; Robin C. Billick
BACKGROUND Solid organ transplant recipients are at increased risk of infection due to chronic immunosuppression. The incidence of varicella zoster virus (VZV) infection is known to be increased in these patients compared with the immunocompetent population. Previous reports suggested that these patients are likely to experience a morbid disease course. Few data currently exist on the course of VZV infections in pancreas or pancreas plus kidney (PK) transplant recipients. OBJECTIVE The goal of this study was to evaluate the incidence and severity of VZV infections in pancreas or PK recipients. STUDY DESIGN We analyzed the transplantation patient database of the Royal Victoria Hospital, identifying 137 pancreas or PK transplantation procedures performed between January 1999 and October 2010, among which we included 98 patients in the study. We subsequently performed a retrospective chart review to evaluate the incidence and severity of VZV infections posttransplantation. RESULTS Our analysis revealed that 11/98 patients developed VZV infections. The majority of infections (~90.9%) occurred within the first 5 years. Most patients (63.6%) were treated on an outpatient basis, whereas only 4 (36.4%) were hospitalized with a mean hospital stay of 9.5 ± 8.42 days. The initial immunosuppressive regimen remained unchanged for the majority of patients. All patients experienced a mild disease course without intensive care unit admission or death. Only 3 patients (27.3%) developed postherpetic neuralgia. CONCLUSION These findings suggest that with timely diagnosis and proper treatment, most patients recover well from a VZV infection.
Cancer | 2017
Feras M. Ghazawi; Elena Netchiporouk; Elham Rahme; Matthew Tsang; Linda Moreau; Steven Glassman; Nathalie Provost; Martin Gilbert; Sara‐Elizabeth Jean; Kevin Pehr; Denis Sasseville; Ivan V. Litvinov
Previous reports of geographic clustering of cutaneous T‐cell lymphoma (CTCL) in Texas, Pittsburgh, and Sweden as well as the occurrence of CTCL in married couples and family members raise a possibility of the existence of an external and potentially preventable trigger(s) for this rare skin cancer.
International Archives of Allergy and Immunology | 2016
Elena Netchiporouk; Linda Moreau; Elham Rahme; Marcus Maurer; Duncan Lejtenyi
Background: The basophil activation test (BAT) using CD63 expression is a sensitive and specific tool for the diagnostic workup of autoimmune chronic spontaneous urticaria (CSU). The definition of a positive BAT is directly dependent on the reference range and the cutoff values established in control populations. As of now, the pediatric reference range and cutoff values of the CD63 BAT remain to be established. Methods: In this study, we analyzed CD63 expression in 80 children (1-17 years old) without chronic urticaria (i.e., controls) and compared the values to those of a pediatric cohort of 105 CSU patients and 23 physical urticaria (PU) patients. Results: Based on the log-normal distribution of CD63 values in control subjects, the reference range and the cutoff for positive CD63 BAT values was established to be 1.2-1.8% (95% CI) and 1.8%, respectively. Children with CSU showed significantly elevated and significantly increased BAT values compared to healthy controls (Wilcoxon rank test p value <0.001). In contrast, no difference was found between BAT results in controls and PU patients. In pediatric CSU patients, a higher disease activity was associated with higher BAT values. Conclusions: Our study provides, for the first time, reference and cutoff values for the CD63 BAT in children. Our findings show that positive CD63 BAT are common in children with CSU and linked to a high disease activity.
JAMA Dermatology | 2017
Elena Netchiporouk; Denis Sasseville; Linda Moreau; Youssef Habel; Elham Rahme
Importance Chronic urticaria (CU) affects 0.1% to 0.3% of children. Most cases have no identifiable trigger and are classified as chronic spontaneous urticaria (CSU). At least half of patients with CSU may have an autoimmune etiology that can be determined in vitro using the basophil activation test (BAT). While 30% to 55% of CU cases resolve spontaneously within 5 years in adults, the natural history and predictors of resolution in children are not known. Objective To assess the comorbidities, natural history of CU, and its subtypes in children and identify predictors of resolution. Design, Setting, and Participants We followed a pediatric cohort with chronic urticaria that presented with hives lasting at least 6 weeks between 2013 and 2015 at a single tertiary care referral center. Exposures Data were collected on disease activity, comorbidities, physical triggers, BAT results, complete blood cell count, C-reactive protein levels, thyroid-stimulating hormone levels, and thyroid peroxidase antibodies. Main Outcomes and Measures We assessed the rate of resolution (defined as absence of hives for at least 1 year with no treatment) and the association with clinical and laboratory markers. Results The cohort comprised 139 children younger than 18 years old. Thirty-one patients (20%) had inducible urticaria, most commonly cold induced. Six children had autoimmune comorbidity, such as thyroiditis and type 1 diabetes. Autoimmune disorders (24 patients [17%]) and CU (17 patients [12%]) were common in family members. Positive BAT results (CD63 levels > 1.8%) were found in 58% of patients. Patients with positive BAT results (CD63 level >1.8%) were twice as likely to resolve after 1 year compared with negative BAT results (hazard ratio [HR], 2.33; 95% CI, 1.08-5.05). In contrast, presence of basophils decreased the likelihood of resolution (HR, 0.40; 95% CI, 0.20-0.99). No correlation with age was found. Chronic urticaria resolved in 43 patients, with a rate of resolution of 10.3% per year. Levels of CD63 higher than 1.8% and absence of basophils were associated with earlier disease resolution. Conclusions and Relevance Resolution rate in children with CU is low. The presence of certain biomarkers (positive BAT result and basophil count) may help to predict the likelihood of resolution.