Fcgammariib Expression As a Prognostic Marker in Chronic Lymphocytic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1727-1727
Author(s):  
Rosa Bosch ◽  
Gerardo Ferrer ◽  
Eva Puy Vicente ◽  
Alba Mora ◽  
Rajendra N. Damle ◽  
...  

Abstract BACKGROUND The Fcγ receptor IIb (FcγRIIb) is an inhibitory Fcγ receptor that suppresses B-cell activation when coligated with B-cell antigen receptor (BCR). Previous studies from our group indicate that the ability of the FcγRIIb to inhibit BCR signaling after coligation is attenuated in Chronic Lymphocytic Leukemia (CLL). Furthermore, in contrast to what has been described in normal murine B-cells, stimulation of the FcγRIIb alone induces proliferation of CLL cells. However, the correlation between FcγRIIb expression, immunophenotypic characteristics, and clinical variables in patients with CLL has not been studied. AIM The aim of this study was to correlate the expression of FcγRIIb on leukemic cells from previously untreated CLL patients and its immunophenotypic features and clinical parameters. METHODS The study population included 112 patients with untreated CLL for whom cryopreserved peripheral blood samples were available before treatment. The diagnosis was based on IWCLL 2008 criteria. The median patients' follow up was 57.92 months (range: 2.23-439.78 months). FcγRIIb expression levels were determined by flow cytometry on CD5+/CD19+ CLL cells using a specific Alexa488-conjugated murine mAb specific for human FcγRIIb. The following combinations were assessed: FcγRIIb/CD38/CD19/CD5, FcγRIIb/CD49d/CD19/CD5, and FcγRIIb/CD69/CD19/CD5. Results were expressed as the ratio between the MFI for FcγRIIb and the MFI for the corresponding isotype (MFIR). FcγRIIb expression levels were correlated with: i) expression of CD49d, CD38 and CD69, ii) clinico-biological characteristics, and iii) clinical outcome. Differences of FcγRIIb expression on dichotomized clinicopathological variables were assessed with Mann Whitney test. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the correlation of FcγRIIb expression with clinical outcome. Best cut-offs for overall survival (OS) and treatment-free survival (TFS) were determined by ROC curves. RESULTS All CD5+CD19+ leukemic cells samples expressed FcγRIIb. However, FcγRIIb expression levels markedly varied between patients (median MFIR: 45.8; interquartile range: 14.9-76.6; 5th -95th percentile: 17.15-111.4). FcγRIIb expression was significantly higher in patients who had high (≥30%) CD49d expression than in those with low (<30%) CD49d expression (p =0.009). No correlation was observed between FcγRIIb expression and age, disease stage, IGHV mutational status or chromosomal abnormalities analyzed by fluorescence in situ hybridization, ZAP70 and CD38. Furthermore, within individual clones, FcγRIIb expression levels were higher on CD38+ or CD49d+ cells than on CD38- or CD49d- cells, respectively (median MFIR: 49.05 vs. 36.72, p =0.001 for CD38+ vs. CD38- cells; and 58.87 vs. 35.55, p <0.001 for CD49d+ vs. CD49d- cells). In univariate analysis, low FcγRIIb expression levels (MFIR< 26.67) were associated with shorter OS (HR 4.01, 95%CI 1.15-13.90, p=0.029), together with older age, advanced stage, and expression of CD38 and CD49d. Advanced stage, unmutated IGHV, and CD38, CD49d and ZAP-70 expression were also associated significantly with shorter TFS. Thus, patients with higher levels of FcγRIIb had better survival than those with lower levels (Log rank test, p = 0.018). A multivariate analysis adjusted for FcγRIIb expression, age, disease stage, CD38, and CD49d identified older age (≥65 yrs) (HR 150.76, 95%CI 5.39-4212.42, p =0.003), low FcγRIIb expression (HR 111.91, 95%CI 6.71-1866.97, p =0.001), advanced stage (B/C) (HR 17.44, 95%CI 1.45-210.24, p =0.024) and CD38 expression (HR 5.02, 95%CI 1.01-25.18, p =0.050) as independent predictors for shorter OS. CONCLUSIONS In this study, FcγRIIb expression on leukemic cells from untreated patients with CLL was found to be an independent prognostic marker for OS, overcoming the prognostic value of CD49d, which is consistent with the key role of the FcγRIIb in the pathogenesis of CLL. Further analysis aimed at validating this observation and to better understand the functional cooperation of FcγRIIb with other molecules, particularly CD49d, are warranted. These studies could open a new venue in CLL treatment. Disclosures Gorlatov: MacroGenics: Employment. Sierra:Novartis: Research Funding; Celgene: Research Funding; Amgen: Research Funding.

Author(s):  
Т.Н. Жевак ◽  
Н.П. Чеснокова ◽  
Т.В. Шелехова ◽  
О.Е. Царева ◽  
И.А. Будник ◽  
...  

Цель. Изучить закономерности изменения экспрессии интерлейкина-10 и интерлейкина-24, обладающих иммуномодулирующим эффектом, при развитии B-клеточного хронического лимфолейкоза. С учетом этого выявить информативные прогностические критерии развития гемобластоза и/или нового подхода к терапии заболевания. Методы. У 120 больных с разными стадиями В-клеточного хронического лимфолейкоза методом твердофазного иммуноферментного анализа исследована динамика уровней интерлейкина-10 и интерлейкина-24 в сыворотке крови. Результаты. Обнаружено закономерное повышение содержания интерлейкина-10 и интерлейкина-24 в сыворотке крови пациентов уже на начальной стадии B-клеточного хронического лимфолейкоза и сохранение их достоверно высоких уровней на последующих стадиях заболевания. Заключение. Обнаруженный нами факт повышения содержания интерлейкина-10 в сыворотке крови пациентов с В-клеточным хроническим лимфолейкозом является фактором риска снижения противоопухолевой защиты организма вследствие подавления им механизмов клеточного иммунитета и способности ингибировать апоптоз малигнизированных клеток. Напротив, повышение экспрессии интерлейкина-24, обладающего проапоптотической активностью и стимулирующего дифференцировку клеток, может способствовать повышению эффективности механизмов противоопухолевой резистентности организма. Устранение дисбаланса продукции и/или содержания указанных цитокинов в сыворотке крови может создать условия повышения эффективности терапии пациентов с В-клеточным хроническим лимфолейкозом. Aim. To study serum levels of immunosuppressive cytokines (interleukin (IL)-10 and IL-24) in patients with B-cell chronic lymphocytic leukemia for assessment of the disease progression and elaboration of a new treatment strategy. Methods. 120 patients with B-cell chronic lymphocytic leukemia were enrolled in the study and divided into four groups according to the disease stage (Rai stage I-IV). Control group included 30 healthy volunteers. Concentrations of IL-10 and IL-24 were measured in serum using the enzyme-linked immunosorbent assay (ELISA). Results. Serum levels of IL-10 and IL-24 levels were significantly increased in all patient groups compared to the control. No difference in the cytokines levels between the patient groups was observed. Conclusion. In patients with B-cell chronic lymphocytic leukemia, the increased serum level of IL-10 might impair the antitumor defence by inhibiting the cell immune response and preventing apoptosis of malignant lymphocytes. On the other hand, the increased serum level of IL-24 might oppose these effects by promoting cellular differentiation and inducing apoptosis in malignant cells. Therefore, correction of IL-10/IL-24 imbalance may be a beneficial therapeutic strategy for patients with B-cell chronic lymphocytic leukemia.


Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 340-344 ◽  
Author(s):  
L Baldini ◽  
R Mozzana ◽  
A Cortelezzi ◽  
A Neri ◽  
F Radaelli ◽  
...  

Abstract Seventy-six consecutive untreated patients with B cell chronic lymphocytic leukemia (B-CLL) and classified according to Binet's staging system were studied at the clinical presentation. Several immunologic parameters (number of total and T circulating lymphocytes and their surface membrane immunoglobulin [Smlg] phenotypes and levels of serum Ig) were evaluated with the aim of identifying a biologic marker of prognostic relevance. In this series of persons, Binet staging confirmed its usefulness as a prognostic index (P less than .001). With regard to Smlg, they were mu-type in 41 cases (53.9%), mu- type plus delta-type in 29 cases (38.2%), alpha-type in one case, and not detectable in five cases. No correlations were found between clinical stage and immunoglobulin phenotype, although all but one patient in stage C showed mu-type Smlg alone. On analyzing the survival curves of our patients according to different Smlg phenotypes, we found that patients with only mu-type Smlg had a poorer prognosis (P less than .05) than those with mu-type plus delta-type; this difference was even more significant (P less than .01) in patients in stage A, whereas there were no statistical differences in those in stages B and C. Because the appearance of surface heavy chain of delta-type could be an expression of cell maturation, these results suggest that in B-CLL the presence of phenotypically more mature leukemic cells may correlate with better clinical prognosis, particularly in the early phase of the disease.


Blood ◽  
2002 ◽  
Vol 100 (8) ◽  
pp. 2973-2979 ◽  
Author(s):  
Anne J. Novak ◽  
Richard J. Bram ◽  
Neil E. Kay ◽  
Diane F. Jelinek

B-cell chronic lymphocytic leukemia (B-CLL) is defined by the accumulation of CD5+ B cells in the periphery and bone marrow. This disease is not characterized by highly proliferative cells but rather by the presence of leukemic cells with significant resistance to apoptosis and, therefore, prolonged survival. B-lymphocyte stimulator (BLyS) is a newly identified tumor necrosis factor (TNF) family member shown to be critical for maintenance of normal B-cell development and homeostasis and it shares significant homology with another TNF superfamily member, APRIL. The striking effects of BLyS on normal B-cell maintenance and survival raises the possibility that it may be involved in pathogenesis and maintenance of hematologic malignancies, including B-CLL. In this study, we investigated the status of APRIL and BLyS expression, as well as their receptors, in this disease. All B-CLL patient cells studied expressed one or more of 3 known receptors for BLyS; however, the pattern of expression was variable. In addition, we demonstrate for the first time that B-CLL cells from a subset of patients aberrantly express BLyS and APRIL mRNA, whereas these molecules were not detectable in normal B cells. Furthermore, we provide in vitro evidence that BLyS protects B-CLL cells from apoptosis and enhances cell survival. Because these molecules are key regulators of B-cell homeostasis and tumor progression, leukemic cell autocrine expression of BLyS and APRIL may be playing an important role in the pathogenesis of this disease.


Leukemia ◽  
2006 ◽  
Vol 20 (3) ◽  
pp. 491-497 ◽  
Author(s):  
C Quiney ◽  
C Billard ◽  
A M Faussat ◽  
C Salanoubat ◽  
A Ensaf ◽  
...  

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Shanye Yin ◽  
Gregory Lazarian ◽  
Elisa Ten Hacken ◽  
Tomasz Sewastianik ◽  
Satyen Gohil ◽  
...  

A hotspot mutation within the DNA-binding domain of IKZF3 (IKZF3-L162R) has been identified as a putative driver in chronic lymphocytic leukemia (CLL); however, its functional effects are unknown. We recently confirmed its role as a CLL driver in a B cell-restricted conditional knock-in model. IKZF3 mutation altered mature B cell development and signaling capacity, and induced CLL-like disease in elderly mice (~40% penetrance). Moreover, we found IKZF3-L162R acts as a gain-of-function mutation, altering DNA binding specificity and target selection of IKZF3, and resulting in overexpression of multiple B-cell receptor (BCR) genes. Consistent with the murine data, RNA-sequencing analysis showed that human CLL cells with mut-IKZF3 [n=4] have an enhanced signature of BCR-signaling gene expression compared to WT-IKZF3 [n=6, all IGHV unmutated] (p&lt;0.001), and also exhibited general upregulation of key BCR-signaling regulators. These results confirm the role of IKZF3 as a master regulator of BCR-signaling gene expression, with the mutation contributing to overexpression of these genes. While mutation in IKZF3 has a clear functional impact on a cardinal CLL-associated pathway, such as BCR signaling, we note that this driver occurs only at low frequency in patients (~3%). Because somatic mutation represents but one mechanism by which a driver can alter a cellular pathway, we examined whether aberrant expression of IKZF3 could also yield differences in BCR-signaling gene expression. We have observed expression of the IKZF3 gene to be variably dysregulated amongst CLL patients through re-analysis of transcriptomic data from two independent cohorts of human CLL (DFCI, Landau et al., 2014; ICGC, Ferreira et al., 2014). We thus examined IKZF3 expression and BCR-signaling gene expression, or the 'BCR score' (calculated as the mean expression of 75 BCR signaling-associate genes) in those cohorts (DFCI cohort, n=107; ICGC cohort, n=274). Strikingly, CLL cells with higher IKZF3 expression (defined as greater than median expression) had higher BCR scores than those with lower IKZF3 expression (&lt;median) (p=0.0015 and p&lt;0.0001, respectively). These findings were consistent with the notion that IKZF3 may act as a broad regulator of BCR signaling genes, and that IKZF3 overexpression, like IKZF3 mutation, may provide fitness advantage. In support of this notion, our re-analysis of a gene expression dataset of 107 CLL samples (Herold Leukemia 2011) revealed that higher IKZF3 expression associated with poorer prognosis and worse overall survival (P=0.035). We previously reported that CLL cells with IKZF3 mutation appeared to increase in cancer cell fraction (CCF) with resistance to fludarabine-based chemotherapy (Landau Nature 2015). Instances of increase in mut-IKZF3 CCF upon treatment with the BCR-signaling inhibitor ibrutinib have been reported (Ahn ASH 2019). These studies together suggest an association of IKZF3 mutation with increased cellular survival following either chemotherapy or targeted treatment. To examine whether higher expression of IKZF3 was associated with altered sensitivity to ibrutinib, we performed scRNA-seq analysis (10x Genomics) of two previously treatment-naïve patients undergoing ibrutinib therapy (paired samples, baseline vs. Day 220). We analyzed an average of 11,080 cells per patient (2000 genes/cell). Of note, following ibrutinib treatment, remaining CLL cells expressed higher levels of IKZF3 transcript compared to pretreatment baseline (both p&lt;0.0001), whereas no such change was observed in matched T cells (n ranging between 62 to 652 per experimental group, p&gt;0.05), suggesting that cells with high expression of IKZF3 were selected by ibrutinib treatment. Moreover, we showed that ibrutinib treatment resulted in consistent upregulation of BCR-signaling genes (e.g., CD79B, LYN, GRB2, FOS, RAC1, PRKCB and NFKBIA) (n ranging between 362 to 1374 per experimental group, all p&lt;0.0001), which were likewise activated by mutant IKZF3. Altogether, these data imply that IKZF3 mutation or overexpression may influence upregulation of BCR-signaling genes and enhance cellular fitness even during treatment with BCR-signaling inhibitors. We highlight our observation that IKZF3 mutation appears to be phenocopied by elevated IKZF3 expression, and suggest that alterations in mRNA or protein level that mimic genetic mutations could be widespread in human cancers. Disclosures Kipps: Pharmacyclics/ AbbVie, Breast Cancer Research Foundation, MD Anderson Cancer Center, Oncternal Therapeutics, Inc., Specialized Center of Research (SCOR) - The Leukemia and Lymphoma Society (LLS), California Institute for Regenerative Medicine (CIRM): Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; VelosBio: Research Funding; Oncternal Therapeutics, Inc.: Other: Cirmtuzumab was developed by Thomas J. Kipps in the Thomas J. Kipps laboratory and licensed by the University of California to Oncternal Therapeutics, Inc., which provided stock options and research funding to the Thomas J. Kipps laboratory, Research Funding; Ascerta/AstraZeneca, Celgene, Genentech/F. Hoffmann-La Roche, Gilead, Janssen, Loxo Oncology, Octernal Therapeutics, Pharmacyclics/AbbVie, TG Therapeutics, VelosBio, and Verastem: Membership on an entity's Board of Directors or advisory committees. Wu:BionTech: Current equity holder in publicly-traded company; Pharmacyclics: Research Funding.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2519-2519 ◽  
Author(s):  
Chia-Huey Lin ◽  
Thomas Kerkau ◽  
Christine Guntermann ◽  
Martin Trischler ◽  
Niklas Beyersdorf ◽  
...  

Abstract B cell chronic lymphocytic leukemia (B-CLL) is characterised by an accumulation of malignant B cells, and impaired humoral and cellular immune responses. Evasion strategies of leukemic cells appear to involve down-regulation of co-stimulatory molecules as well as increased resistance to apoptosis. Here we provide data supporting a novel concept to treat B-CLL with a humanized, superagonistic monoclonal antibody specific for CD28 (TGN1412). Superagonistic anti-CD28 antibodies have been shown to activate human T cells in vitro without requirement for engagement of the T cell antigen receptor (Luhder et al., J. Exp. Med. 2003. 197(8):955–66). Indicative of their activation, TGN1412-triggered T cells from healthy donors upregulate, among other activation markers, CD40L, that has been reported to promote anti-leukemic effects when ectopically expressed on B-CLL cells (Wierda et al., Blood. 2000. 96 (9): 2917–2924). In this report, the responses of PBMCs from B-CLL patients to soluble TGN1412 were examined. We show that in a dose-dependent fashion, polyclonal T cell activation was induced by TGN1412 including proliferation, cytokine production and induction of activation markers such as CD25, CD71, CD134 (Ox40), CTLA-4 (CD152) and CD154 (CD40L). Significantly, modulation of malignant B-CLL cells was also observed. MHC class II molecules (HLA-DR), CD95 and the co-stimulatory molecules CD80 and CD86, but not the proliferation marker Ki-67, were strongly up-regulated upon TGN1412 stimulation. These data suggested that improved antigen-presenting functions of B-CLL cells were induced by TGN1412. Accordingly, preliminary data indicate that B-CLL cells isolated from TGN1412 stimulated cultures induced enhanced proliferation of both allogeneic and autologous T cells, and importantly, TGN1412 activated T cells exhibited enhanced CTL-activity against B-CLL cells. In conclusion, our data suggest that TGN1412 induces polyclonal T cell expansion and activation as well as increased APC function of B-CLL cells. They imply that TGN1412 may have future therapeutic benefit for B-CLL patients.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 53-53 ◽  
Author(s):  
Krzysztof Giannopoulos ◽  
Iwona Hus ◽  
Li Li ◽  
Agnieszka Bojarska-Junak ◽  
Jochen Greiner ◽  
...  

Abstract Definition of appropriate target antigens might open new avenues to antigen targeted immunotherapies for patients with B-cell chronic lymphocytic leukemia (B-CLL). We screened the mRNA expression of tumor associated antigens (TAAs), from the literature (fibromodulin, survivin, OFA-iLRP, BAGE, G250, MAGE1, PRAME, proteinase, Syntaxin, hTERT, WT-1), and TAAs defined earlier by serological analysis of cDNA expression libraries from leukemic cells (PINCH, HSJ2, MAZ, MPP11, RHAMM/CD168, NY-Ren60). Peripheral blood mononuclear cells from 43 B-CLL patients and 20 healthy volunteers (HVs) were examined by conventional and quantitative RT-PCR. mRNA of RHAMM/CD168, fibromodulin, syntaxin and NY-Ren60 was expressed in 55–90%, mRNA of HSJ2, MAZ and OFA-iLRP in 90–100% of the patients. No expression of WT-1, h-TERT, BAGE, G250, MAGE1 and survivin was observed. Low (2–20%) expression frequencies of MPP11, PINCH, PRAME and proteinase were detected. RHAMM/CD168, fibromodulin, PRAME and MPP11 showed expression in B-CLL patients, but not in HVs. Because of the exquisite tissue expression of RHAMM/CD168 and its high expression frequency in B-CLL patients even in early stages of disease, mixed lymphocyte peptide culture (MLPC), enzyme-linked immunosorbent spot (ELISPOT) and flow cytometry were performed for antigen specific T cells. In MLPC, RHAMM specific responses by CD8+HLA-A2/R3tetramer+CCR7-CD45RAhigh effector T cells were detected. Moreover, we observed an enhanced RHAMM/CD168 specific CD8+ T cell response after vaccination in one from four HLA-A2 positive B-CLL patients vaccinated with tumor cell lysate pulsed dendritic cells. Therefore, RHAMM/CD168 is an interesting candidate antigen for future immunotherapies in both ZAP-70 (+) and ZAP-70 (−) B-CLL patients.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2773-2773
Author(s):  
Krzysztof Giannopoulos ◽  
Alexander Krober ◽  
Anna Dmoszynska ◽  
Jacek Rolinski ◽  
Hartmut Dohner ◽  
...  

Abstract Background and Aims: Differential expression of molecules in patients with B-cell chronic lymphocytic leukemia (B-CLL) might define suitable targets for T cell based vaccines and/or antibody approaches. Methods: We assessed the mRNA expression of the tumor associated antigen (TAA) RHAMM/CD168 defined earlier by serological analysis of cDNA expression libraries (SEREX) from leukemic cells. Results: Peripheral blood mononuclear cells from 40 B-CLL patients and 20 healthy volunteers (HVs) were examined by quantitative RT-PCR. A leukemia-restricted expression of the antigen RHAMM/CD168 was observed in 39/40 B-CLL patients in contrast to the absence of its expression in HVs. To evaluate the immunogenicity of this novel LAA, mixed lymphocyte peptide cultures (MLPCs), followed by enzyme-linked immunosorbent spot (ELISPOT) and flow cytometry assays were performed to detect antigen-specific CD8+ T cells. RHAMM/CD168 specific responses by CD8+ HLA-A2/R3tetramer+CCR7-CD45RAhigh effector T cells were detected. As these CD8+ T cells contribute to the elimination of RHAMM+ CLL cells, we questioned whether expression of the antigen would be associated with a better survival. RHAMM/CD168 expression revealed to be higher in patients with unmutated IgVH status. RHAMM normalized against the housekeeping gene TATA binding protein (TBP), i.e. the RHAMM/TBP ratio was defined as a prognostic surrogate marker for B-CLL. B-CLL patients with a RHAMM/TBP ratio > 1.67 showed a significantly shorter treatment free survival (TFS) (Fig. 1). A tendency towards higher RHAMM/TBP expression ratios was observed in B-CLL cases with del11q. Conclusion: RHAMM/CD168 is a novel LAA in B-CLL patients, an antigen correlating with the clinical course of the disease. Therefore, we consider RHAMM/CD168 an interesting target for immunotherapy in early stage B-CLL patients, especially with worse prognosis (IgVH unmutated). Figure 1. Treatment-free-survival (TFS) according to RHAMM/TBP ratio Figure 1. Treatment-free-survival (TFS) according to RHAMM/TBP ratio


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2343-2343
Author(s):  
Liguang Chen ◽  
Bing Cui ◽  
George Chen ◽  
Michelle Salcedo ◽  
Carlo M. Croce ◽  
...  

Abstract Abstract 2343 Poster Board II-320 B-cell receptor (BCR) signaling arguably plays an important role in the pathogenesis and/or progression of chronic lymphocytic leukemia. Ligation of the BCR by F(ab)2 anti-μ can induce phosphorylation of p72Syk, BLNK, phospholipase C-gamma (PLCγ) and other downstream adapter/signaling molecules, inducing intracellular calcium flux and cellular activation. Prior studies found that CLL cells that expressed unmutated Ig heavy-chain variable region genes (IGHV) and the zeta-associated protein of 70 kD (ZAP-70) generally experienced greater levels of activation following treatment with anti-μ than did CLL cells that lacked expression of ZAP-70. However, we found unusual cases that lacked expression of ZAP-70 that also responded vigorously to treatment with anti-μ, suggesting that other factors contribute to the noted differences in BCR-signaling. Analyses for expression of microRNAs by microarray revealed that CLL cells that used unmutated IGHV and that expressed ZAP-70 expressed higher levels of certain microRNAs than did cases that used mutated IGHV and that lacked expression of ZAP-70. One of such microRNA, miR-155, was found to target mRNA encoding SHIP-1, a phosphatase that plays a critical role in modulating the level of BCR signaling in normal B cells. Using quantitative assays for miR-155 we found high-level expression of this microRNA was associated with proficient BCR signaling in CLL. To examine whether miR-155 could modulate the levels of SHIP-1 and/or BCR signaling in CLL cells we transfected primary leukemia cells from each of multiple patients with control oligo-RNAs, miR-155, or a specific inhibitor of miR-155 (miR-155 inhibitor). Twenty-four hours later the cells were stimulated with anti-μ or control antibody and then examined 10 minutes later for expression of SHIP-1, induced calcium influx, or phosphorylation of kinases and adapter proteins that are involved in BCR signaling. CLL cells that had low expression levels of miR-155 and that were poorly responsive BCR had significantly higher levels of calcium influx and phosphorylated p72Syk, BLNK, and PLCγ in response to anti-μ following transfection with miR-155 than following mock transfection or transfection with control oligo-RNA. Conversely, CLL cells that had high expression levels of miR-155 and highly responsive BCR were made to have significantly higher amounts of SHIP-1 protein and to have significantly lower relative levels of phosphorylated protein and calcium influx in response to anti-μ following transfection with the miR-155 inhibitor than did mock transfected CLL cells. These results identify miR-155 as a factor that can modulate BCR signaling in CLL in part by regulating the relative expression level of SHIP-1. These results demonstrate that differential expression of microRNAs in CLL can influence physiologic features that potentially contribute to disease progression. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2867-2867 ◽  
Author(s):  
Sameer A. Parikh ◽  
Susan L Slager ◽  
Kari G. Rabe ◽  
Neil E. Kay ◽  
James R Cerhan ◽  
...  

Abstract Background Approximately 2-8% patients with chronic lymphocytic leukemia (CLL) will transform to diffuse large B-cell lymphoma (DLBCL, Richter syndrome [RS]). Clinical characteristics and molecular markers at the time of CLL diagnosis are associated with the risk of RS; however, there are no data regarding germline genetic variations and the risk of RS. Genomewide association studies (GWAS) have shown several single-nucleotide polymorphisms (SNPs) that are associated with a higher risk of familial CLL. It is not known whether any of these polymorphisms also predispose to RS. Methods Since 2002, all consecutive patients with newly diagnosed (<9 months diagnosis) CLL at Mayo Clinic were offered enrollment into a prospective genetic epidemiology study. Patients completed extensive epidemiologic questionnaires and baseline clinical, laboratory, and biologic data were abstracted using a standard protocol. Genotyping of germline tissue at diagnosis was performed using an Illumina iSelect panel and Affymetrix 6.0 SNP chip. All patients were prospectively and longitudinally followed at defined time-points with systematic collection of data on treatments, second cancers, and RS. All patients with biopsy-proven DLBCL during follow-up were considered to have undergone transformation into RS. Time to RS was calculated from CLL diagnosis date until RS or until last follow-up date for those with no RS. SNPs were modeled in two ways: ordinal and dominant. Cox regression was used to estimate hazard ratio (HR) for individual SNPs with time to transformation. Results Thirteen of the GWAS-discovered SNPs associated with risk of developing CLL were available and genotyped on 620 CLL patients. Median age at diagnosis of CLL was 62 years (range 27-88), and 428 (69%) were male. Three hundred and ten (51%) patients were low (0) Rai stage, 271 (45%) were intermediate (I-II) Rai stage, and 22 (4%) were advanced (III-IV) Rai stage. The immunoglobulin heavy chain gene was unmutated in 189 (40%) patients; 157 (32%) patients expressed ZAP-70, 163 (29%) expressed CD38 and 104 (31%) expressed CD49d. Fluorescence in-situ hybridization (FISH) revealed that 210 (41%) patients had del13q, 90 (18%) patients had trisomy 12, 37 (7%) had del11q, 23 (5%) had del17p and 141 (28%) had no detectable FISH abnormalities. As of last follow-up, 239 (39%) patients received therapy for CLL. After a median follow-up of 5.9 years (range 0-11), 15 (2.4%) patients developed biopsy-proven RS. The median time to RS in these 15 patients was 4.5 years (range 1.0-8.7 years). The ordinal HR for the 13 SNPs tested, their corresponding genes, and p-values are shown in Table 1. Germline polymorphisms in a single SNP, rs4987852, encoding for BCL2 (chromosome 18), was significantly associated with an increased risk of RS (ordinal HR=3.9; 95% CI=1.6-9.8; p-value=0.004). This allele was present in 48/605 (8%) non-transformed CLL patients compared to 4/15 (27%) of patients with RS. Time to RS according to the Kaplan-Meier analysis for rs4987852 is shown in Figure 1. This SNP is located in a region in which t(14;18) translocation breakpoints commonly occur in follicular lymphoma and overexpression of BCL2 leads to an increased incidence of B-cell lymphomas in mice. Conclusion Our results suggest that inherited genetic polymorphisms predispose CLL patients to develop RS. Specifically, SNP (rs4987852) present on the BCL2 gene on chromosome 18 in CLL is associated with an increased risk of transformation to RS. These observations require replication in other CLL cohorts. Disclosures: Shanafelt: Genentech: Research Funding; Glaxo-Smith-Kline: Research Funding; Cephalon: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding.


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