BCL-6 Overexpression as a Predictor for Endometriosis in Patients Undergoing In Vitro Fertilization

OBJECTIVE

To evaluate the positive predictive value (PPV) of endometrial BCL-6 overexpression as a noninvasive screening test endometriosis in patients undergoing in vitro fertilization (IVF).

METHODS

Retrospective cohort study at a university-affiliated private practice. Inclusion criteria were reproductive age females currently undergoing IVF with a diagnosis of unexplained infertility or unexplained recurrent pregnancy loss. Those with endometrial BCL-6 overexpression underwent laparoscopic surgery with an indication for treatment of suspected endometriosis. The primary outcome was the PPV of endometrial BCL-6 testing to surgically diagnose endometriosis. Statistical analysis was performed using SPSS v.25.0.

RESULTS

Seventy-five patients met inclusion criteria for our study. The PPV of BCL-6 testing for endometriosis was 96%. Of those patients without endometriosis, 100% had other inflammatory pelvic pathologies, which were diagnosed and treated at the time of laparoscopy.

CONCLUSIONS

Endometrial BCL-6 overexpression has a high PPV for diagnosing endometriosis and can help identify a patient population that may require surgical treatment before embryo transfer.

Clinicopathologic features and prognostic analysis of Waldeyer ring B-cell lymphoma

This retrospective study is to explore the clinicopathologic, immunophenotypic, and molecular genetic features of Waldeyer ring B-cell lymphoma (WR-BCL).Tissue arrays from 65 WR-BCL cases were subjected to pathologic and immunophenotypic detections. Expression of Epstein-Barr virus-encoded small RNA (EBER) was detected by in situ hybridization. Interferon regulatory factor 4 (IRF4), BCL-2, BCL-6, and C-myelocytomatosis viral oncogeneav (MYC) gene abnormalities were investigated using interphase fluorescence in situ hybridization.Among the 65 patients, there were 12 nasopharynx cases, 49 tonsil cases, and 4 tongue root cases. Moreover, there were 49 cases of diffuse large BCL (DLBCL) and 16 cases of follicular lymphoma (FL). More than 60% of the patients had Ann Arbor stage III/IV disease, with infiltrated neighboring organs, invaded spleens, and increased lactate dehydrogenase (LDH) levels. Tumor cells were positive for multiple myeloma antigen 1 (MUM1), BCL-2, BCL-6, and C-MYC. EBER expression was detected in lymphoma cells of 2 cases. Alteration frequencies of IRF4, BCL-2, BCL-6, and C-MYC were 24.6%, 32.3%, 27.7%, and 30.7%, respectively. Approximately 67.69% cases had stages 0 to II disease, while 32.31% cases had stage III disease. Five-year overall survival rate was 65.12%. Eastern Cooperative Oncology Group performance status (ECOG) score ≥2 was the only adverse factor for overall survival. IRF4/MUM1, C-MYC, and CD10 expressions were related to poor disease prognosis. WR-BCLs were largely dependent on ECOG, LDH, and bone marrow involvement. WR-DLBCL was associated with poor survival outcomes compared with WR-FL.The WR-DLBCLs have distinct clinicopathologic features, with correlations between the IRF4/MUM1, C-MYC and CD10 expressions, ECOG, LDH, bone marrow involvement, and the disease prognosis.

Generation and characterization of a monoclonal antibody against human BCL6 for immunohistochemical diagnosis

Background

Human B-cell lymphoma 6 (BCL6) gene, usually coding protein of 706 amino acids, is closely associated with large B cell lymphoma. Researches showed that protein mutation or change of expression levels usually happened in the mounting non-hodgkin lymphoma (NHL). Thus BCL6 is considered to be involved in germinal center (GC)-derived lymphoma.

Results

The BCL6_1-350 gene codons were optimized for prokaryotic system. After expression of BCL6_1-350 in E. coli, the BCL6_1-350 protein was purified with Ni column. Then the BCL6_1-350 protein, mixing with QuickAntibody-Mouse5W adjuvant, was injected into Balb/c mice. After immunization and cell fusion, a stable cell line named 1E6A4, which can secrete anti-BCL6 antibody, was obtained. The isotype of 1E6A4 mAb was determined as IgG_2a, and the affinity constant reached 5.12×10¹⁰ L/mol. Furthermore, the specificity of the mAb was determined with ELISA, western blot and immunohistochemistry. Results indicated that the 1E6A4 mAb was able to detect BCL6 specifically and sensitively.

Conclusions

BCL6_1-350 antigen has been successfully generated with an effective and feasible method, and a highly specific antibody named 1E6A4 against BCL6 has been screened and characterized in this study, which was valuable in clinical diagnosis.

Tumor suppressor BTG1 limits activation of BCL6 expression downstream of ETV6-RUNX1

Translocation t(12;21) (p13;q22), giving rise to the ETV6-RUNX1 fusion gene, is the most common genetic abnormality in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). This translocation usually arises in utero, but its expression is insufficient to induce leukemia and requires other cooperating genetic lesions for BCP-ALL to develop. Deletions affecting the transcriptional coregulator BTG1 are frequently observed in ETV6-RUNX1-positive leukemia. Here we report that Btg1 deficiency enhances the self-renewal capacity of ETV6-RUNX1-positive mouse fetal liver-derived hematopoietic progenitors (FL-HPCs). Combined expression of the fusion protein and a loss of BTG1 drive upregulation of the proto-oncogene Bcl6 and downregulation of BCL6 target genes, such as p19Arf and Tp53. Similarly, ectopic expression of BCL6 promotes the self-renewal and clonogenic replating capacity of FL-HPCs, by suppressing the expression of p19Arf and Tp53. Together these results identify BCL6 as a potential driver of ETV6-RUNX1-mediated leukemogenesis, which could involve loss of BTG1-dependent suppression of ETV6-RUNX1 function.

Expression of Master Regulators of T-cell, Helper T-cell and Follicular Helper T-cell Differentiation in Angioimmunoblastic T-cell Lymphoma

Objective It has been postulated that the normal counterpart of angioimmunoblastic T-cell lymphoma (AITL) is the follicular helper T-cell (TFH). Recent immunological studies have identified several transcription factors responsible for T-cell differentiation. The master regulators associated with T-cell, helper T-cell (Th), and TFH differentiation are reportedly BCL11B, Th-POK, and BCL6, respectively. We explored the postulated normal counterpart of AITL with respect to the expression of the master regulators of T-cell differentiation. Methods We performed an immunohistochemical analysis in 15 AITL patients to determine the expression of the master regulators and several surface markers associated with T-cell differentiation. Results BCL11B was detected in 10 patients (67%), and the surface marker of T-cells (CD3) was detected in all patients. Only 2 patients (13%) expressed the marker of naïve T-cells (CD45RA), but all patients expressed the marker of effector T-cells (CD45RO). Nine patients expressed Th-POK (60%), and 7 (47%) expressed a set of surface antigens of Th (CD4-positive and CD8-negative). In addition, BCL6 and the surface markers of TFH (CXCL13, PD-1, and SAP) were detected in 11 (73%), 8 (53%), 14 (93%), and all patients, respectively. Th-POK-positive/BCL6-negative patients showed a significantly shorter overall survival (OS) than the other patients (median OS: 33.0 months vs. 74.0 months, p=0.020; log-rank test). Conclusion Many of the AITL patients analyzed in this study expressed the master regulators of T-cell differentiation. The clarification of the diagnostic significance and pathophysiology based on the expression of these master regulators in AITL is expected in the future.

AMP kinase promotes Bcl6 expression in both mouse and human T cells

The transcription factor Bcl6 is a master regulator of follicular helper T (T_FH) cells, and understanding the signaling pathway that induces Bcl6 and T_FH cell differentiation is therefore critical. IL-2 produced during T cell activation inhibits Bcl6 expression but how T_FH cells evade IL-2 inhibition is not completely understood. Here we show that Bcl6 is highly up-regulated in activated CD4 T cells following glucose deprivation (GD), and this pathway is insensitive to inhibition by IL-2. Similar to GD, the glucose analog 2-deoxyglucose (2DG) inhibits glycolysis, and 2DG induced Bcl6 expression in activated CD4 T cells. The metabolic sensor AMP kinase (AMPK) is activated when glycolysis is decreased, and the induction of Bcl6 by GD was inhibited by the AMPK antagonist compound C. Additionally, activation of AMPK by the drug AICAR caused Bcl6 up-regulation in activated CD4 T cells. When mice were immunized with KLH using AICAR as an adjuvant, there was a strong T_FH-dependent enhancement of KLH-specific antibody (Ab) responses, and higher Bcl6 expression in T_FH cells in vivo. Activation of AMPK strongly induced BCL6 and the up-regulation of T_FH cell marker expression by human CD4 T cells. Our data reveal a major new pathway for T_FH cell differentiation, conserved by both mouse and human T cells. Mature T_FH cells are reported to have a lower metabolic state compared to T_H1 cells. Our data indicates that decreased metabolism may be deterministic for T_FH cell differentiation, and not simply a result of T_FH cell differentiation.

Synthetic Lethal Screen Demonstrates That a JAK2 Inhibitor Suppresses a BCL6-dependent IL10RA/JAK2/STAT3 Pathway in High Grade B-cell Lymphoma

We demonstrate the usefulness of synthetic lethal screening of a conditionally BCL6-deficient Burkitt lymphoma cell line, DG75-AB7, with a library of small molecules to determine survival pathways suppressed by BCL6 and suggest mechanism-based treatments for lymphoma. Lestaurtinib, a JAK2 inhibitor and one of the hits from the screen, repressed survival of BCL6-deficient cells in vitro and reduced growth and proliferation of xenografts in vivo BCL6 deficiency in DG75-AB7 induced JAK2 mRNA and protein expression and STAT3 phosphorylation. Surface IL10RA was elevated by BCL6 deficiency, and blockade of IL10RA repressed STAT3 phosphorylation. Therefore, we define an IL10RA/JAK2/STAT3 pathway each component of which is repressed by BCL6. We also show for the first time that JAK2 is a direct BCL6 target gene; BCL6 bound to the JAK2 promoter in vitro and was enriched by ChIP-seq. The place of JAK2 inhibitors in the treatment of diffuse large B-cell lymphoma has not been defined; we suggest that JAK2 inhibitors might be most effective in poor prognosis ABC-DLBCL, which shows higher levels of IL10RA, JAK2, and STAT3 but lower levels of BCL6 than GC-DLBCL and might be usefully combined with novel approaches such as inhibition of IL10RA.

IgG-Immune Complexes Promote B Cell Memory by Inducing BAFF

Memory B cell responses are vital for protection against infections but must also be regulated to prevent autoimmunity. Cognate T cell help, somatic hypermutation, and affinity maturation within germinal centers (GCs) are required for high-affinity memory B cell formation; however, the signals that commit GC B cells to the memory pool remain unclear. In this study, we identify a role for IgG-immune complexes (ICs), FcγRs, and BAFF during the formation of memory B cells in mice. We found that early secretion of IgG in response to immunization with a T-dependent Ag leads to IC-FcγR interactions that induce dendritic cells to secrete BAFF, which acts at or upstream of Bcl-6 in activated B cells. Loss of CD16, hematopoietic cell-derived BAFF, or blocking IC:FcγR regions in vivo diminished the expression of Bcl-6, the frequency of GC and memory B cells, and secondary Ab responses. BAFF also contributed to the maintenance and/or expansion of the follicular helper T cell population, although it was dispensable for their formation. Thus, early Ab responses contribute to the optimal formation of B cell memory through IgG-ICs and BAFF. Our work defines a new role for FcγRs in GC and memory B cell responses.

Immunologic and cytogenetic markers expressed in non-Hodgkin lymphoma of head and neck

Very often, the first doctor who examines a patient with malignant lymphoma is an ENT specialist, because non-Hodgkin lymphoma is five times more frequent than Hodgkin disease in the head and neck region. Approximately 25% of extranodal lymphoma occurs in the head and neck and extranodal presentation is twice as frequent as nodal presentation. This paper present a study of the patients from ENT, Head & Neck Surgery Clinic of Coltea Clinical Hospital, Bucharest, Romania, diagnosed with malignant lymphoma. We developed a specific scheme for collecting data about patients, together with pathology details, immunology and cytogenetic markers. We tried to establish a relation between immunologic and cytogenetic markers and the clinical evolution of non-Hodgkin lymphoma. For this study, we analyzed data regarding CD10, CD5, CD20, Bcl-2, Bcl-6, Ki67 expression obtained from 58 patients with follicular lymphoma. An attempt was made to correlate the presence of certain immunohistochemical and cytogenetic markers with the evolution and aggressiveness of the disease, and we can say that Bcl-2 is positive in all tumor subtypes, being associated relatively frequently with CD5 expression, and is a marker of poor prognosis, while Bcl-6 is positive especially in the tumor forms associated with the predominance of small cells and is a marker of favorable prognosis.

B-cell differentiation immunophenotypes in classical Hodgkin lymphomas

The bcl6/CD10/MUM1/CD138 B-cell differentiation immunophenotypes were analysed in 101 cases of classical Hodgkin lymphomas (cHL) aiming to elucidate their histogenesis. Three major bcl6/CD10/MUM1/CD138 immunophenotypes were distinguished on the basis of the immunohistochemical positivity of Hodgkin and Reed-Sternberg (H/RS) cells: (a) the late germinal center (GC)/early post-GC B-cell-like immunophenotype (bcl6-/CD10-/MUM1+/CD138-); 59/101 cases (59%), (b) the post-GC B-cell-like immunophenotype (bcl6-/CD10-/MUM1+/CD138+); 24/101 cases (24%) and (c) the indeterminate immunophenotype (bcl6+/CD10-/MUM1+/CD138-: 14 cases and bcl6+/CD10-/MUM1+/CD138+: four cases); 18/101 cases (18%). The above findings indicate that H/RS cells in most cHL display bcl6/CD10/MUM1/CD138 immunophenotypes consistent with late GC/early post-GC or post-GC B-cell differentiation. In addition, H/RS cells in a small fraction of cHL display indeterminate bcl6/CD10/MUM1/CD138 immunophenotypic profiles which are characterized by simultaneous expression of GC, late GC/early post-GC and post-GC B-cell differentiation proteins. These immunophenotypic profiles do not correspond to the differentiation immunophenotypes of normal B-cells and their identification in a part of cHL suggests that the differentiation process of H/RS cells is not complete in a fraction of these cells and/or is still ongoing at the time of observation.