Prevalência do rearranjo do gene ROS1 em carcinoma de pulmão de células não pequenas não escamoso, EGFR e ALK negativo: análise de uma coorte brasileira / Prevalence of ROS1 gene rearrangements in EGFR-Negative and ALK-negative nonsquamous NSCLC: analysis of a Brazilian cohort

Introdução: A prevalência do câncer de pulmão tem aumentado cerca de 2% ao ano e é considerado um problema de saúde pública mundial, sendo a principal causa de morte por câncer entre homens e mulheres. O Câncer de Pulmão de Células Não Pequenas (CPCNP) representa 85-90% dos cânceres de pulmão. A detecção do rearranjo do gene ROS1, considerada um importante fator preditivo para direcionamento terapêutico, constitui uma etapa crítica no tratamento de CPCNP. Objetivo: Avaliar a prevalência do rearranjo do gene ROS1 em pacientes portadores de CPCNP não escamoso, sem mutação de EGFR ou rearranjo de ALK, diagnosticados na Região da Foz do Rio Itajaí, Estado de Santa Catarina, Brasil, no período de 02/01/2019 a 27/07/2020. Materiais e Métodos: Estudo observacional, retrospectivo e prospectivo, descrito e analítico com 95 pacientes que possuíam material de biópsia suficiente para a realização de novas análises e que não apresentavam mutação de EGFR ou rearranjo de ALK. Os pacientes com imuno-histoquímica positiva para a proteína ROS1 foram testados pelo método de FISH, utilizando-se uma sonda de DNA do tipo break-apart para o gene ROS1. Foi realizada uma análise descritiva da amostra, e os resultados foram apresentados em números absolutos e porcentagens, representados por tabelas. O teste de qui-quadrado (χ2) foi empregado para comparação das frequências entre os grupos analisados. Resultados: 52,6% foram pacientes do sexo masculino; a idade mediana foi de 64 anos; 54,7% declararam-se tabagistas; 40,0% apresentavam doença estágio IV; 29,5% apresentaram tumores com alta expressão de PD-L1. Quanto a expressão de ROS1 por imuno-histoquímica: 89,5% foram identificados como ROS1+ em 0% das células tumorais, 4,2% como ROS1+ em <70% das células, e 6,3% como ROS1+ em ≥70% das células do tumor; portanto, 10,5% apresentaram resultados positivos para expressão de ROS1. Estes pacientes foram submetidos à análise de rearranjo de ROS1 pelo método de FISH e 7 (7,4%) apresentaram resultados positivos. Conclusão: Na população estudada, a análise pelo método de FISH mostrou uma prevalência de 7,4% para rearranjos do gene ROS1

Introduction: Lung cancer prevalence has been increasing at rate of 2% per year and is considered a major public health concern worldwide, being the main cause of cancer death among women and men. Non-small cell lung cancer (NSCLC) represents 85-90% of total lung cancer. Detecting the rearrangement of the ROS1 gene is critical to the treatment of NSCLC. Objective: To assess the prevalence of the ROS1 gene rearrangement in patients diagnosed with non-squamous NSCLC patients diagnosed between January 2019 to July 2020 at Foz do Rio Itajaí, in the state of Santa Catarina, Brazil. Materials and Methods: This is a retrospective and prospective observational study Ninety-five NSCLC whose tumors were negative for EGFR mutation and ALK rearrangement and who had enough tumor tissue to carry out additional molecular analysis. Patients whose tumors were positive for ROS1 by immune-histochemistry were tested using by FISH using a break-apart DNA probe (Abbot Molecular) for the ROS1 gene. A descriptive analysis was performed and results were presented as absolute frequencies and percentages and depicted in charts. Frequencies were compared with the chi-squared test (χ2). Results: 52,6% were male, mean and median age were 65,10 and 64 years, respectively. 54,7% self-declared as smokers; 40,0% had stage IV disease; 29,5% had tumours with high expression of PD-L1. Regarding the expression of ROS1 by immunohistochemistry: 89,5% were identified as ROS1+ in 0% of cells, 4,2% as ROS1+ in <70% of cells, and 6,3% as ROS1+ in ≥70% of the cells; therefore, 10,5% displayed positive results for the expression of ROS1+. These tumors were subjected to the analysis of ROS1 rearrangement by FISH and 7 (7,4%) were positive. Conclusion: We observed 7,4% prevalence for ROS1 gene rearrangements in this pre-selected population

Significance of myc gene rearrangement and its correlation with prognosis in diffuse large B cell lymphoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the relationship between myc gene rearrangement and myc protein expression in diffuse large B cell lymphoma (DLBCL), and their correlation with prognosis.</p><p><b>METHODS</b>One hundred and six cases of DLBCLs with follow-up data were analyzed using interphase fluorescence in situ hybridization (FISH) technique. Immunophenotyping analysis for CD20, CD3, myc, Mum-1, CD10, bcl-6 was also performed using EnVision immunohistochemistry.</p><p><b>RESULTS</b>The percentages of tumor cells expressing myc, Mum-1, CD10 and bcl-6 were 70.8%, 56.6%, 21.7% and 26.4%, respectively. Twenty six cases (24.5%) were of GCB type and the rest (75.5%) were of non-GCB (non germinal center) type. The myc rearrangement was identified in 13 (12.3%) of 106 cases. 13 cases showed to be of non-GCB type. There was no correlation between myc rearrangement and myc protein expression. DLBCLs (n = 13) with myc rearrangement showed significantly poorer overall survival (OS) and progression free survival (PFS), with a median OS and PFS time of 4.7 and 3.2 months, respectively (for OS and PFS, P < 0.001). Multivariate analysis using Cox proportional hazard model confirmed that myc rearrangement, ECOG performance status of 2-4, immunophenotyping subgroup and myc protein were independent factors affecting the prognosis and significantly associated with the survival. However, myc rearrangement was the strongest prognostic factor.</p><p><b>CONCLUSIONS</b>DLBCL with myc gene rearrangement is a subgroup of non-GCB DLBCL with poor outcome. It is an independent and useful factor for prognosis in DLBCL. Expression of myc is influenced by many factors and myc rearrangement may be one of these factors.</p>

Comparative study between primary mediastinal B-cell lymphoma and non-mediastinal diffuse large B-cell lymphoma by immunoglobulin gene rearrangement and Epstein-Barr virus infection detection / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the differences between primary mediastinal B-cell lymphoma (PMBCL) and non-mediastinal conventional diffuse large B-cell common lymphoma (DLBCL) in immunoglobulin gene rearrangement and EB virus infections.</p><p><b>METHODS</b>Twenty cases of PMBCL and 30 cases of non-mediastinal DLBCL were collected from September, 2000 to May, 2011. Pathological data were retrospectively analysed. Immunoglobulin heavy chain and light chain gene rearrangements and EBER in-situ hybridization were performed.</p><p><b>RESULTS</b>Six of 20 cases of PMBCL showed monoclonal gene rearrangement, all of which were weakly detected. Twenty-seven of 30 cases of ordinary diffuse large B-cell lymphoma showed monoclonal gene rearrangement, which were strongly detected (90.0%). Only 1 of 20 cases PMBCL and 2 of 30 cases of DLBCL were positive for EBER in-situ hybridization.</p><p><b>CONCLUSIONS</b>The detection rate of immunoglobulin gene rearrangement is significantly lower in PMBCL than that of non-mediastinal DLBCL. However, EB virus infection rates are very low in both types of lymphomas.</p>

Assessment of BIOMED-2 assays for detection of clonal Ig gene rearrangements in mature B-cell lymphomas / 中华病理学杂志

<p><b>OBJECTIVE</b>To evaluate the efficiency of the BIOMED-2 PCR assay and its implication in the diagnosis of mature B-cell non-Hodgkin's lymphomas.</p><p><b>METHODS</b>Clinical, morphological and immunohistochemical features of 72 cases of non-Hodgkin's lymphomas were studied, including 25 reactive lymphoid hyperplasia, 37 diffuse large B cell lymphomas (DLBCL) and 35 extranodal marginal zone lymphomas of mucosa associated lymphoid tissues (MALT lymphoma and in addition, 25 cases of reactive lymphoid hyperplasia were used as the controls). DNA was exacted from the paraffin embedded formalin fixed tissue blocks and the quality of DNA was assessed using the BIOMED-2 specimen control reaction. Adequate samples were then analyzed by BIOMED-2 for immunoglobulin heavy and kappa light chain rearrangements.</p><p><b>RESULTS</b>Adequate DNA was obtained in 83 of 97 samples, including 60 mature B cell lymphomas and 23 reactive lymphoid hyperplasia. Clonal B-cell gene rearrangements were detected in 57 of 60 (95%) lymphomas. In contrast, clonal Ig gene rearrangements were not detected in any of the 23 cases of reactive lymphoid hyperplasia.</p><p><b>CONCLUSION</b>BIOMED-2 assay is highly sensitive and specific for the detection of clonal B cell gene rearrangement using routine paraffin embedded formalin fixed specimens.</p>

Bcl-2 gene rearrangement in Jordanian follicular and diffuse large B-cell lymphomas

Follicular lymphoma [FL], a common subtype of non-Hodgkin's lymphoma [NHL] in the West, represents a rare subtype in Jordan. Bcl-2 gene rearrangement plays a crucial role in the biology of the vast majority of FL and a substantial number of diffuse large B-cell lymphoma [DLBCL] in the West; but its presence has not been studied in Jordan. Our aims are to document if bcl-2 gene rearrangement exists in Jordanian FL and DLBCL, and if present to determine whether its frequency among these lymphomas is different from the West and therefore may be responsible for some of the epidemiological differences seen between Jordan and the West. The study was conducted in the year 2001 using polymerase chain reaction [PCR], to detect bcl-2 gene rearrangement in paraffin sections in 5 FL and 23 DLBCL cases diagnosed at the Department of Pathology at Jordan University of Science and Technology, Irbid, Jordan. Two sets of primers including the major breakpoint region [MBR] and the minor cluster region [MCR] were used. Amplifiable DNA was extracted from all cases. Bcl-2 gene rearrangement was seen among 4 [80%] of 5 FL cases, and 8 [35%] of 23 DLBCL cases. The majority of the rearrangements involved the MBR; however, one fourth of cases [one of 4 FL; 2 of 8 DLBCL] with bcl-2 rearrangement involved the MCR. Bcl-2 gene rearrangement was seen in the vast majority of Jordanian FL cases and approximately one third of all DLBCL cases. These figures are similar to those reported in the West, and therefore bcl-2 gene rearrangement does not help in explaining the epidemiological differences of NHL between Jordan and the West. The presence of bcl-2 gene rearrangement in DLBCL may define a subset of lymphomas that may be biologically and clinically unique and different from the rest of DLBCL

Receptor selection and B cell immune tolerance / 生物医学工程学杂志

The immune system of mammalian has developed sophisticated mechanism to deal with diverse unknown antigens by random rearrangement of V, D and J antigen gene fragments. The immune self-tolerance is the mechanism to avoid self-destruction by the gene rearrangement generated autoreactive lymphocytes. Until recently it was believed that autoreactive lymphocytes are either deleted or rendered unable to respond by the supposed cell or clone selection mechanism. However, recent findings from a number of laboratories suggest instead of cell selection but receptor selection plays an essential role in immune self-tolerance. Receptor selection is carried out by secondary or nested rearrangement of antigen receptor gene fragments, and can occur at different stages of lymphocyte differentiation. Furthermore, secondary rearrangement of receptor gene also plays an important role in shaping immune response after the interaction of receptor with antigen by altering its specificity.

Real-time quantitative study of minimal residual disease in childhood B cell acute lymphoblastic leukemia / 中华儿科杂志

<p><b>OBJECTIVE</b>The study was aimed to investigate the feasibility and clinical significance of quantitative detection of minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) by real-time quantitative polymerase chain reaction (RQ-PCR).</p><p><b>METHODS</b>Clonal IgH gene rearrangements of samples at diagnosis were identified by standard PCR assay with consensus primers. Monoclonal IgH gene rearrangements were analyzed using DNAPLOT software. Upstream primers were designed with the Primer Express software and allele specific oligonucleotide developed complementary to the V-D or D-J junction. Samples at diagnosis were serially diluted to generate the patient specific standard curves. RQ-PCR method was used to quantify the MRD of the follow up samples collected at five time points during chemotherapy. To check the quantity and quality of DNA, the investigators used RQ-PCR analysis for the albumin gene.</p><p><b>RESULTS</b>Totally 16 monoclonal IgH gene rearrangements were identified from 34 patients with B-ALL. The analysis of the 16 monoclonal rearrangements showed that the most frequently used V segment was from V3 family and J segment from J4 and J6. The RQ-PCR sensitivity of 10(-4) to 10(-5) was mostly reached. Non-specific amplification was seen in 6 patients. The number of inserted and deleted nucleotides did not appear to be related to the sensitivity (P > 0.05). The correlation coefficients of all 16 standard curves were excellent (> or = 0.99). The mean slope of the standard curves was -3.4 +/- 0.37 and the mean intercept was 24.3 +/- 2.95. MRD analysis of follow up samples from the 16 patients showed an association between high degree of MRD and relapse. There was no apparent relationship between MRD degree at the end of induction chemotherapy and other high risk factors of ALL (P > 0.05).</p><p><b>CONCLUSION</b>The study showed that the above approach with RQ-PCR was applicable to clinical detection of MRD in childhood ALL. Quantitative and dynamic study of MRD was of prognostic importance.</p>

Cell biology, molecular embryology, Lamarckian and Darwinian selection as evolvability

The evolvability of vertebrate systems involves various mechanisms that eventually generate cooperative and nonlethal functional variation on which Darwinian selection can operate. It is a truism that to get vertebrate animals to develop a coherent machine they first had to inherit the right multicellular ontogeny. The ontogeny of a metazoan involves cell lineages that progressively deny their own capacity for increase and for totipotency in benefit of the collective interest of the individual. To achieve such cell altruism Darwinian dynamics rescinded its original unicellular mandate to reproduce. The distinction between heritability at the level of the cell lineage and at the level of the individual is crucial. However, its implications have seldom been explored in depth. While all out reproduction is the Darwinian measure of success among unicellular organisms, a high replication rate of cell lineages within the organism may be deleterious to the individual as a functional unit. If a harmoniously functioning unit is to evolve, mechanisms must have evolved whereby variants that increase their own replication rate by failing to accept their own somatic duties are controlled. For questions involving organelle origins, see Godelle and Reboud, 1995 and Hoekstra, 1990. In other words, modifiers of conflict that control cell lineages with conflicting genes and new mutant replication rates that deviate from their somatic duties had to evolve. Our thesis is that selection at the level of the (multicellular) individual must have opposed selection at the level of the cell lineage. The metazoan embryo is not immune to this conflict especially with the evolution of set-aside cells and other modes of self-policing modifiers (Blackstone and Ellison, 1998; Ransick et al., 1996. In fact, the conflict between the two selection processes permitted a Lamarckian soma-to-germline feedback loop. This new element in metazoan ontogeny became the evolvability of the vertebrate adaptive immune system and life as we know it now. We offer the hypothesis that metazoan evolution solved this ancient conflict by evolving an immunogenetic mechanism that responds with rapid Lamarckian efficiency by retaining the ancient reverse transcriptase enzyme (RNACopyright DNA copying discovered by Temin in 1959 (see Temin, 1989) and found in 1970 in RNA tumor viruses by Temin and Baltimore), which can produce cDNA from the genome of an RNA virus that infects the cells. It seems that molecular