Molecular characterisation of chromosome 7q deletion in splenic marginal zone B cell lymphoma

La délétion du chromosome 7q est l'anomalie cytogénétique la plus caractéristique du lymphome de la zone marginale splénique (LZMS). Une étude par hybridation génomique comparative de haute résolution a été conduite sur une série de 27 échantillons de LZMS afin de détecter des micro-remaniements du chromosome 7q. Une région commune de délétion (RCD) de 10,6 Mb a été délimitée sur le chromosome 7q. De plus, une microdélétion somatique du gène AHCYL2 (S-adenosyl-homocystéine hydrolase-like 2) a été détectée au sein de la RCD, définissant la plus petite RCD connue sur le chromosome 7q32 dans le SMZL et l'anomalie la plus fréquente de notre série (10/27, 37%). Bien que le séquençage du gène AHCYL2 n'a pas mis en évidence de mutation somatique, la délétion monoallélique du gène AHCYL2 est corrélée à la sous-expression de transcrits du gène AHCYL2 indiquant une haplo-insuffisance. La fonction précise de AHCYL2 reste inconnue, mais certaines données suggèrent que les protéines de type AHCYL peuvent réguler l'activité de l'enzyme AHCY (Sadénosyl- homocystéine hydrolase) et par conséquent affecter les mécanismes de transméthylation. En outre, nous avons identifié, pour la première fois dans le LZMS, une mutation R882H du gène DNMT3A (1/27, 3,7%) impliqué également dans les processus de méthylation. Ces résultats suggèrent que la dérégulation des voies métaboliques impliquées dans la méthylation peut jouer un rôle crucial dans la pathogenèse du LZMSThe chromosome 7q deletion is the most characteristic alteration in splenic marginal zone lymphoma (SMZL). High-resolution genome-focused approach was performed on 27 SMZL samples to identify submicroscopic genetic alterations on chromosome 7q. A 10.6 Mb-length common deleted region (CDR) of chromosome 7q was precisely delineated and a somatic microdeletion of the S-adenosyl-homocysteine hydrolase-like 2 (AHCYL2) gene was further detected within the CDR, defining the most frequent finding in this series (10/27, 37%) and the smallest CDR on chromosome 7q32. Although the sequencing of AHCYL2 gene did not show any evidence of somatic mutation, the monoallelic AHCYL2 gene deletion was directly correlated with underexpression of AHCYL2 transcripts, indicating a typical pattern of haploinsufficiency. The precise role of AHCYL2 remains unknown, but some data suggest that the AHCY-like proteins may regulate the activity of AHCY (S adenosylhomocysteine hydrolase) and consequently may affect the methylation metabolism. In addition, we report on a DNMT3A-R882H mutation (1/27, 3.7%) for the first time in SMZL. These findings suggest that methylation pathway dysfunction may play a crucial role in the pathogenesis of SMZ

Molecular characterisation of chromosome 7q deletion in splenic marginal zone B cell lymphoma

La délétion du chromosome 7q est l'anomalie cytogénétique la plus caractéristique du lymphome de la zone marginale splénique (LZMS). Une étude par hybridation génomique comparative de haute résolution a été conduite sur une série de 27 échantillons de LZMS afin de détecter des micro-remaniements du chromosome 7q. Une région commune de délétion (RCD) de 10,6 Mb a été délimitée sur le chromosome 7q. De plus, une microdélétion somatique du gène AHCYL2 (S-adenosyl-homocystéine hydrolase-like 2) a été détectée au sein de la RCD, définissant la plus petite RCD connue sur le chromosome 7q32 dans le SMZL et l'anomalie la plus fréquente de notre série (10/27, 37%). Bien que le séquençage du gène AHCYL2 n'a pas mis en évidence de mutation somatique, la délétion monoallélique du gène AHCYL2 est corrélée à la sous-expression de transcrits du gène AHCYL2 indiquant une haplo-insuffisance. La fonction précise de AHCYL2 reste inconnue, mais certaines données suggèrent que les protéines de type AHCYL peuvent réguler l'activité de l'enzyme AHCY (Sadénosyl- homocystéine hydrolase) et par conséquent affecter les mécanismes de transméthylation. En outre, nous avons identifié, pour la première fois dans le LZMS, une mutation R882H du gène DNMT3A (1/27, 3,7%) impliqué également dans les processus de méthylation. Ces résultats suggèrent que la dérégulation des voies métaboliques impliquées dans la méthylation peut jouer un rôle crucial dans la pathogenèse du LZMSThe chromosome 7q deletion is the most characteristic alteration in splenic marginal zone lymphoma (SMZL). High-resolution genome-focused approach was performed on 27 SMZL samples to identify submicroscopic genetic alterations on chromosome 7q. A 10.6 Mb-length common deleted region (CDR) of chromosome 7q was precisely delineated and a somatic microdeletion of the S-adenosyl-homocysteine hydrolase-like 2 (AHCYL2) gene was further detected within the CDR, defining the most frequent finding in this series (10/27, 37%) and the smallest CDR on chromosome 7q32. Although the sequencing of AHCYL2 gene did not show any evidence of somatic mutation, the monoallelic AHCYL2 gene deletion was directly correlated with underexpression of AHCYL2 transcripts, indicating a typical pattern of haploinsufficiency. The precise role of AHCYL2 remains unknown, but some data suggest that the AHCY-like proteins may regulate the activity of AHCY (S adenosylhomocysteine hydrolase) and consequently may affect the methylation metabolism. In addition, we report on a DNMT3A-R882H mutation (1/27, 3.7%) for the first time in SMZL. These findings suggest that methylation pathway dysfunction may play a crucial role in the pathogenesis of SMZ

Etude de la dualité fonctionnelle du TGFb lors de la progression tumorale sur un modèle cellulaire de cancer du sein

LYON1-BU Santé (693882101) / SudocSudocFranceF

Deep Multi-Instance Learning Using Multi-Modal Data for Diagnosis of Lymphocytosis

ct. We investigate the use of recent advances in deep learning and propose an end-to-end trainable multi-instance convolutional neural network within a mixture-of-experts formulation that combines information from two types of data—images and clinical attributes—for the diagnosis of lymphocytosis. The convolutional network learns to extract meaningful features from images of blood cells using an embedding level approach and aggregates them. Moreover, the mixture-of-experts model combines information from these images as well as clinical attributes to form an end-to-end trainable pipeline for diagnosis of lymphocytosis. Our results demonstrate that even the convolutional network by itself is able to discover meaningful associations between the images and the diagnosis, indicating the presence of important unexploited information in the images. The mixture-of-experts formulation is shown to be more robust while maintaining performance via. a repeatability study to assess the effect of variability in data acquisition on the predictions. The proposed methods are compared with different methods from literature based both on conventional handcrafted features and machine learning, and on recent deep learning models based on attention mechanisms. Our method reports a balanced accuracy of 85.41% and outperfroms the handcrafted feature-based and attention-based approaches as well that of biologists which scored 79.44%, 82.89% and 77.07% respectively. These results give insights on the potentials of the applicability of the proposed method in clinical practice. Our code and datasets can be found at https://www.github.com/msahasrabudhe/lymphoMIL

Toll-like receptor expression and function differ between splenic marginal zone B cell lymphoma and splenic diffuse red pulp B cell lymphoma

International audienceIn splenic marginal zone lymphoma (SMZL), specific and functional Toll-like Receptor (TLR) patterns have been recently described, suggesting their involvement in tumoral proliferation. Splenic diffuse red pulp lymphoma with villous lymphocytes (SDRPL) is close to but distinct from SMZL, justifying here the comparison of TLR patterns and functionality in both entities. Distinct TLR profiles were observed in both lymphoma subtypes. SDRPL B cells showed higher expression of TLR7 and to a lesser degree TLR9, in comparison to SMZL B cells. In both entities, TLR7 and TLR9 pathways appeared functional, as shown by IL-6 production upon TLR7 and TLR9 agonists stimulations. Interestingly, circulating SDRPL, but not SMZL B cells, constitutively expressed CD86. In addition, stimulation with both TLR7 and TLR9 agonists significantly increased CD80 expression in circulating SDRPL but not SMZL B cells. Finally, TLR7 and TLR9 stimulations had no impact on proliferation and apoptosis of SMZL or SDRPL B cells. In conclusion, SMZL and SDRPL may derive from different splenic memory B cells with specific immunological features that can be used as diagnosis markers in the peripheral blood

Effect of pneumatic tube transport on T lymphocyte subsets analysis

International audienceBackground: Pneumatic tube system (PTS) for transportation of blood specimens may present with advantages for hospital organization as it provides faster tube transfer from medical wards to routine labs. These characteristics are expected to result in faster sample processing and decreased turnaround time, therefore benefiting the patient particularly in emergency units. However, PTS could affect sample quality and therefore laboratory results. Within the context of routine lab certification, effects of PTS on routine cellular immunology analyses, especially on determination of T lymphocyte subpopulations, need to be evaluated. Methods: Paired EDTA blood samples were collected from 30 healthy donors. For each pair, one sample was hand-delivered by a courier while the other was transported through a PTS of 2.4 km long (1.6 miles) with two 90-degree turns and one-U turn generating a speed of 5 m/s with a maximal acceleration of 2 g-force. The percentages of CD31 cells, CD41 and CD81 T-cells and their absolute counts were assessed by flow cytometry. Results: For every parameter, results measured by flow cytometry were not significantly different after transport by PTS or hand-delivery. Results comparison revealed an excellent linear correlation between both delivery methods (R ranged from 0.969 to 0.982; P < 0.01). Bland-Altman plots also showed good agreement, indicating that results were not influenced by the transport method. Conclusions: Our results suggest that, pending validation using clinical samples, PTS does not present with pre-analytical drawbacks and is thus a reliable system for blood samples transportation when performing T cell subset phenotyping.