Flow Cytometric Detection of ZAP-70 in Chronic Lymphocytic Leukemia: Correlation With Immunocytochemistry and Western Blot Analysis

2007 ◽  
Vol 131 (1) ◽  
pp. 50-56
Author(s):  
Graham W. Slack ◽  
Juanita Wizniak ◽  
Laith Dabbagh ◽  
Xinzhe Shi ◽  
Pascal Gelebart ◽  
...  

Abstract Context.—Expression of ZAP-70 in chronic lymphocytic leukemia (CLL) predicts worse clinical outcome in patients with early-stage disease. It has become important to include ZAP-70 in the immunophenotyping panel used to diagnose CLL, commonly performed by flow cytometry (FC). Nevertheless, the methodology used to detect ZAP-70 by FC has not been extensively evaluated. Objective.—To describe our FC method for detecting ZAP-70 in CLL and assess whether this assay is useful in estimating the ZAP-70 protein level in CLL cells. Design.—ZAP-70 expression was assessed by FC in 45 consecutive newly diagnosed CLL patients, and the results were correlated with those of immunocytochemistry and Western blot analysis. Results.—With >25% ZAP-70–positive B cells as the cutoff, the FC results had a perfect concordance with those of immunocytochemistry (39/39, 100%) and Western blot analysis (7/7, 100%). The use of autofluorescence controls was found to be superior to other alternatives. Overall, 19 (42%) of 45 cases were ZAP-70 positive in our series. Since only 7 cases (16%) had >20% to 30% ZAP-70–positive B cells, the cutoff of >25% readily separated CLL into positive and negative groups in most cases. ZAP-70 positivity was significantly associated with atypical morphology but not other laboratory parameters evaluated. Conclusions.—With proper specimen processing and the use of directly fluorescence-conjugated anti–ZAP-70 antibody, one can readily incorporate ZAP-70 into the routine FC study panel for CLL. Our data suggest that FC is a rapid and useful method to estimate the ZAP-70 protein expression level in CLL.

2020 ◽  
Vol 20 (4) ◽  
pp. 429-436
Author(s):  
Roghayeh Ijabi ◽  
Parisa Roozehdar ◽  
Reza Afrisham ◽  
Hemen Moradi-Sardareh ◽  
Saeed Kaviani ◽  
...  

Introduction: Parallel with the progression of Chronic Lymphocytic Leukemia (CLL), the levels of 78KDa Glucose-Regulated Protein (GRP78) and Hypoxia-Inducible Factor 1 alpha (HIF-1α) are increased as they may activate the induction of anti-apoptotic proteins such as BCL2 Associated Athanogene 3 (BAG3). Previous studies have indicated that there is a positive correlation among GRP78, HIF-1α and BAG3. Objective: This study aimed to evaluate the effect of metabolic factors involved in invasive CLL on apoptotic factors. Methods: A case-control study was conducted on 77 patients diagnosed with CLL along with 100 healthy individuals. Cell blood count was performed for all participants. According to Binet's classification, CLL patients were divided into different groups. B cells were isolated from the peripheral blood of CLL patients by binding to anti-CD19 beads. The expression of BAG3, GRP78 and HIF-1α genes was analyzed using the RT-PCR method. To confirm the results of RT-PCR, western blot analysis was carried out. Results: The results showed that there was a strong association among the expression of BAG3, GRP78 and HIF-1α. The stage of CLL in patients was highly correlated with the expression rate of each gene (p<0.001). Accordingly, the western blot analysis indicated that the concentrations of GRP78 and HIF-1α were significantly higher than the expression of BAG3, considering the stage of CLL. Conclusion: It was shown that increased expression of GRP78 and HIF-1α could result in the elevation of BAG3, as well as the disease progression. Therefore, the role of these metabolic factors might be more pronounced compared with the anti-apoptotic agents to monitor disease progression in CLL patients.


Hematology ◽  
2002 ◽  
Vol 2002 (1) ◽  
pp. 193-213 ◽  
Author(s):  
Neil E. Kay ◽  
Terry J. Hamblin ◽  
Diane F. Jelinek ◽  
Gordon W. Dewald ◽  
John C. Byrd ◽  
...  

Abstract This update of early stage B-cell chronic lymphocytic leukemia (B-CLL) embraces current information on the diagnosis, biology, and intervention required to more fully develop algorithms for management of this disease. Emphasis on early stage is based on the rapid advancement in our understanding of the disease parameters and our increasing ability to predict for a given early stage patient whether there is a need for more aggressive management. In Section I, Dr. Terry Hamblin addresses the nature of the disease, accurate diagnostic procedures, evidence for an early “preclinical” phase, the use of newer prognostic features to distinguish who will be likely to progress or not, and whether it is best to watch or treat early stage disease. In Section II, Dr. Neil Kay and colleagues address the biologic aspects of the disease and how they may relate to disease progression. Review of the newer insights into gene expression, recurring genetic defects, role of cytokines/autocrine pathways, and the interaction of the CLL B cell with the microenvironment are emphasized. The relationship of these events to both trigger disease progression and as opportunities for future therapeutic intervention even in early stage disease is also considered. In Section III, Dr. John Byrd and colleagues review the historical and now current approaches to management of the previously untreated progressive B-CLL patient. They discuss what decision tree could be used in the initial decision to treat a given patient. The use of single agents versus newer combination approaches such as chemoimmunotherapy are discussed here. In addition, the place of marrow transplant and some of the newer antibodies available for treatment of B-CLL are considered. Finally, a challenge to utilize our growing knowledge of the biology of B-CLL in the early stage B-CLL is proffered.


Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 686
Author(s):  
Sandra Ballester ◽  
Begoña Pineda ◽  
Patricia Rodrigues ◽  
Eduardo Tormo ◽  
María José Terol ◽  
...  

Angiogenesis process contributes to the pathogenesis of B-cell chronic lymphocytic leukemia (B-CLL) being the levels of VEGFA and bFGF higher in patients than in healthy controls. Our aim was to evaluate the implication of angiogenesis factors genetic variants in the predisposition to B-CLL and their association with clinical factors and survival. We performed a population-based case-control study in 224 Spanish B-CLL patients and 476 healthy randomly selected controls to evaluate susceptibility to developing B-CLL. Six polymorphisms were evaluated: rs1109324, rs1547651, rs3025039 (+936 C>T), rs833052 of the VEGFA gene, rs1449683 (c.233C>T) of the bFGF gene and (−710 C>T) of the VEGFR1 gene. The association between clinical parameters and patient outcome was analyzed. Carriers of the CT/TT variants of rs3025039 showed a significant protective effect against developing B-CLL. The CT/TT variants of rs1449683 show a tendency towards the development of the disease and the same variants associated significantly with higher genetic risk and with reduced disease free survival. Moreover, the association persisted in the early-stage disease subgroup. Our study provides evidence of the protective effect of the T/- rs3025039 VEGFA variant against B-CLL development and the association of CT/TT variants of the rs1449683 bFGF gene with genetic risk and an adverse survival.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1064-1064
Author(s):  
Asish K Ghosh ◽  
Tait Shanafelt ◽  
George A Calin ◽  
Carlo M. Croce ◽  
Linda Wellik ◽  
...  

Abstract Background: B-Chronic Lymphocytic Leukemia (CLL) is predominantly characterized as a clonal B-cell disorder where a minor fraction of CLL B cells proliferate, but the majority of these cells are non-cycling. Importantly, CLL B cells also exhibit apoptosis resistance that results from a complex set of redundant mechanisms. This latter feature presents a significant problem in relation to disease progression and developing effective therapies in CLL. Previously, we and others have reported that leukemic CLL cells spontaneously secrete pro-angiogenic vascular endothelial growth factor (VEGF) that can significantly enhance CLL leukemic B cell apoptosis resistance via unknown mechanisms. In addition, the molecular mechanism of the constitutive upregulation of VEGF in CLL B cells is unknown. Methods and Results: Here, we report that CLL B cells express a high level of HIF-1α protein under normoxic conditions as compared to that of normal B cells in Western blot analysis using a specific antibody. Accumulation of HIF-1α in CLL B cells resulted in upregulation of its downstream target VEGF. To comprehend this abnormal overexpression of HIF-1α, we have examined the status of the von Hippel-Lindau gene product (pVHL) that is responsible for HIF-1α degradation by Western blot analysis and found it to be either absent or notably low level in CLL B cells as compared to that of normal B cells. Furthermore, we have shown by in vitro reporter gene assays that miR-92a, a microRNA known to be overexpressed in CLL B cells, can target the VHL 3′-untranslated region (UTR) and is likely a reason for the depressed levels of pVHL in CLL B cells. To validate our hypothesis, we transiently transfected the human embryonic kidney cell line (293T) with miR-92a and observed a dose-dependent repression of pVHL level. Post-transcriptional regulation of the VHL gene was further confirmed when we observed a subtle but definite increase of the pVHL levels monitored by immunoblot following nucleofection of the antisense oligo targeted to miR-92a into primary CLL B cells. To examine whether HIF-1α is functionally active in CLL B cells, we performed co-immunoprecipitation experiments and found that HIF-1α forms an active complex by physical association with the transcriptional co-activator p300 and phospho-STAT3 in CLL B cells. The latter molecule is known to be constitutively expressed in CLL B cells but its function has been unknown. Subsequently, we have found via chromatin immunoprecipitation analyses in CLL B cells that HIF-1α and STAT3 are bound to the VEGF promoter and also recruit RNA polymerase II, further substantiating that this complex likely functions in the activation of VEGF transcription. Summary: Overall, our data show that CLL B cells express constitutively elevated HIF-1α levels in normoxia due, at least in part, to miR-92a regulated diminished pVHL expression. This is a unique previously undescribed mechanism for enhanced HIF-1α levels in human malignancy. We believe that Increased VEGF expression is associated with the combined effects of HIF-1α, p300 and constitutively active STAT3 as a functional complex and is an explanation for the VEGF-based autocrine pathway found in CLL B cells. These findings now provide additional strategy points for interrupting the VEGF autocrine pathway in CLL B cells.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1267-1267
Author(s):  
Haiming Chen ◽  
Mingjie Li ◽  
Richard A. Campbell ◽  
Melinda S. Gordon ◽  
Dror Shalitin ◽  
...  

Abstract We have discovered a novel mechanism leading to blood vessel formation involving transdifferentiation of monocytes into endothelial cells by tumor cell production of pleiotrophin (PTN), a protein highly produced by myeloma (H. Chen et al, Blood, 2005; Yeh et al BJH, 2006). Arsenic trioxide (ATO) induces apoptosis of cancer cells directly through a number of mechanisms, and this drug has also been shown to inhibit angiogenesis. However, it remains unknown whether ATO affects the earliest stages of angiogenesis and vasculogenesis important in tumor development. We purified human monocytes (CD14+) and cultured these cells on collagen I-coated dishes. mCSF was added to the cells after 1 hour of culture. PTN was added twice to the culture, once after 24 hours and again after 5 days with or without ATO or bortezomib. FLK-1 expression (VEGFR-2) showed that the cells incubated on collagen I without drugs formed tube-like structures in the presence of PTN and mCSF. However, the tube-like structures disappeared after adding either the IC50 (5x10−6M) dose or low (5x10−7M) dose of ATO. FLK-1 staining remains in the tube-like structures with low doses (3x10−12M) of bortezomib. In order to examine whether ATO or bortezomib affects endothelial gene expression when monocytes are induced to transdifferentiate in the presence of these cytokines, we also examined expression using RT-PCR on endothelial cell genes (vascular endothelial growth factor receptor-2 (Flk-1), Tie-2 and von Willebrand factor (vWF)) and Western blot analysis for protein expression. The results of both RT-PCR and Western blot analysis showed that the expression of endothelial markers was blocked at both the higher (5x10−6M) and lower (5x10−7M) doses of ATO. In contrast, the expression of endothelial markers was not reduced by adding low dose bortezomib (3x10−12M). We further examined the effects of ATO and bortezomib on early stage angiogenesis in vivo using the chorioallantoic membrane (CAM) assay. Fertilized chick eggs were incubated horizontally at 38°C in a humidified incubator, windowed by day 3 of incubation and processed by day 8. The tested micro-sponge with ATO (5x10−6M) or bortezomib (3x10−11M) or control reagents was implanted on the CAM. The eggs were sealed with adhesive tape and returned to the incubator for 48 hours. The assay scored positive when two independent observers reported a significant reduction of vessels in the treated area. The results of the CAM assay showed that compared to saline, ATO significantly reduced new macroscopic and microscopic vessel formation. In contrast, bortezomib did not affect angiogenesis in the CAM assay. These experiments define a previously unrecognized novel mechanism by which ATO may have anti-angiogenetic effects in cancer patients-preventing the transdifferentiation of monocytes into endothelial cells by PTN. They also suggest ATO as a potential new specific agent to inhibit angiogenesis resulting from transdifferentiation of monocytes into vascular endothelial cells driven by pleiotrophin and mCSF. These results suggest a novel way by which anti-cancer agents may impact angiogenesis.


Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 4679-4685 ◽  
Author(s):  
William G. Wierda ◽  
Susan O'Brien ◽  
Xuemei Wang ◽  
Stefan Faderl ◽  
Alessandra Ferrajoli ◽  
...  

Abstract The clinical course for patients with chronic lymphocytic leukemia is extremely heterogeneous. The Rai and Binet staging systems have been used to risk-stratify patients; most patients present with early-stage disease. We evaluated a group of previously untreated patients with chronic lymphocytic leukemia (CLL) at initial presentation to University of Texas M. D. Anderson Cancer Center to identify independent characteristics that predict for overall survival. Clinical and routine laboratory characteristics for 1674 previously untreated patients who presented for evaluation of CLL from 1981 to 2004 were included. Univariate and multivariate analyses identified several patient characteristics at presentation that predicted for overall survival in previously untreated patients with CLL. A multivariate Cox proportional hazards model was developed, including the following independent characteristics: age, β-2 microglobulin, absolute lymphocyte count, sex, Rai stage, and number of involved lymph node groups. Inclusion of patients from a single institution and the proportion of patients younger than 65 years may limit this model. A weighted prognostic model, or nomogram, predictive for overall survival was constructed using these 6 characteristics for 5- and 10-year survival probability and estimated median survival time. This prognostic model may help patients and clinicians in clinical decision making as well as in clinical research and clinical trial design.


Author(s):  
Stephan Stilgenbauer ◽  
Richard R. Furman ◽  
Clive S. Zent

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) is usually diagnosed in asymptomatic patients with early-stage disease. The standard management approach is careful observation, irrespective of risk factors unless patients meet the International Workshop on CLL (IWCLL) criteria for “active disease,” which requires treatment. The initial standard therapy for most patients combines an anti-CD20 antibody (such as rituximab, ofatumumab, or obinutuzumab) with chemotherapy (fludarabine/cyclophosphamide [FC], bendamustine, or chlorambucil) depending on multiple factors including the physical fitness of the patient. However, patients with very high-risk CLL because of a 17p13 deletion (17p-) with or without mutation of TP53 (17p-/ TP53mut) have poor responses to chemoimmunotherapy and require alternative treatment regimens containing B-cell receptor (BCR) signaling pathway inhibitors. The BCR signaling pathway inhibitors (ibrutinib targeting Bruton's tyrosine kinase [BTK] and idelalisib targeting phosphatidyl-inositol 3-kinase delta [PI3K-delta], respectively) are currently approved for the treatment of relapsed/refractory CLL and all patients with 17p- (ibrutinib), and in combination with rituximab for relapsed/refractory patients (idelalisib). These agents offer great efficacy, even in chemotherapy refractory CLL, with increased tolerability, safety, and survival. Ongoing studies aim to determine the best therapy combinations with the goal of achieving long-term disease control and the possibility of developing a curative regimen for some patients. CLL is associated with a wide range of infectious, autoimmune, and malignant complications. These complications result in considerable morbidity and mortality that can be minimized by early detection and aggressive management. This active monitoring requires ongoing patient education, provider vigilance, and a team approach to patient care.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 7087-7087
Author(s):  
Amir Hossein Daneshmanesh ◽  
Mohammad Hojat Farsangi ◽  
Ali Moshfegh ◽  
Salam Khan ◽  
Anders Österborg ◽  
...  

7087 Background: The PI3K/AKT/mTOR is a central pathway activated in many types of cancer. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase regulating cell growth, proliferation and survival. In CLL cells PI3K pathway is constitutively activated leading to AKT activation with subsequent phosphorylation of other downstream signaling molecules. ROR1 is a type I transmembrane RTK, overexpressed and constitutively phosphorylated in CLL. A unique anti-ROR1 mAb directed against CRD region of ROR1 was capable of inducing direct apoptosis as well as dephosphorylating the ROR1 molecule. Here, we investigated the apoptotic effect of the anti-ROR1 mAb and effects on the PI3K/AKT/mTOR pathway using primary CLL cells. Methods: Apoptosis was detected by the MTT assay and Annexin V/PI methods in a 24 h assay. Antibody untreated and treated cell lysates were prepared and subjected to Western blot analysis for identification of the signaling molecules involved in apoptosis induced by the ROR1 mAb. We analysed total and phosphorylated levels of the following signaling proteins: AKT, p-AKT, PI3K, p-PI3K, mTOR, p-mTOR, ERK, p-ERK, PKC and p-PKC. Phosphoproteins were measured before incubation with the mAb and after 20 min-24 h. Results: ROR1 detection on surface of the CLL cells was 80-85% and apoptotic frequency 45-50%. Western blot analysis showed decreased levels of p-AKT, p85 isoform of p-PI3K and p-mTOR in treated compared to untreated samples. No changes in the phosphorylation levels of ERK and PKC proteins were seen. Conclusions: Incubation of CLL cells with the anti-ROR1 mAb induced apoptosis of CLL cells. Apoptosis was preceded by dephosphorylation of PI3K, AKT and mTOR proteins indicating deactivation of these proteins by the ROR1 mAb. In untreated CLL cells no effect was noted. Furthermore no dephosphorylation of PKC or ERK was seen. We suggest that activation of mTOR might occur via the PI3K/AKT pathway and may be a survival signal in CLL cells associated with the aberrant expression of ROR1. Further studies are warranted to understand better the signaling pathways associated with ROR1 and the downstream signaling effects of ROR1 targeting drugs.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5307-5307
Author(s):  
Nitin Jain ◽  
Michael J. Keating ◽  
Alessandra Ferrajoli ◽  
Marina Konopleva ◽  
Deborah A. Thomas ◽  
...  

Background Ofatumumab is a human IgG1-kappa monoclonal antibody that binds to CD20 on normal B cells and on B chronic lymphocytic leukemia cells, resulting in B cell lysis. Ofatumumab has single-agent activity in patients (pts) with refractory CLL (Wierda, JCO 2010). Pts with CLL who have early stage disease (Rai 0-II) but have high-risk prognostic markers such as deletion 17p or deletion 11q have an increased risk of disease progression. Currently, these pts are offered watch-and-wait approach. The objective of this Phase II study is to evaluate the efficacy of ofatumumab in treating these pts with the goal to delay time to first chemoimmunotherapy treatment. Methods Pts with CLL/SLL were eligible provided they had high-risk for progression based on the presence of at least one of the following features: Rai stage II, serum beta-2 microglobulin (β2M) ≥3 mg/L, absolute lymphocyte count ≥25,000/µL, unmutated (≤2%) IGHV gene or mutated IGHV3-21, ZAP70 positive, CD38 positive (≥ 30%), or 11q or 17p deletion by FISH. Pts having a 2008 IWCLL/NCI-WG indication for CLL treatment were not eligible. Pts with Rai stage III-IV CLL were not eligible. Ofatumumab 300 mg dose 1, then 1000 mg weekly for 7 additional weeks (8 doses) was administered. Response assessment, including bone marrow evaluation, was done at least 2 months after last dose of ofatumumab and pts were followed for progression-free survival and time to first chemoimmunotherapy. Results Twenty-five pts (9 women, 16 men) were enrolled so far. The median age was 59 yrs (range, 40-81). The baseline characteristics are listed in the Table. Fifty percent of pts had unmutated IGHV gene. Thirty-four percent of pts had high-risk cytogenetic by FISH analysis. The median follow-up on the study is 4.7 months (range, 0.5-26). Grade 3-4 adverse events included infusion reaction in 6 pts. Autoimmune hepatitis with grade 4 ALT, grade 4 AST, and grade 4 alkaline phosphatase elevations was seen in 1 pt. Other grade 3-4 toxicities included rash (1 pt), shingles (1 pt), and tumor lysis (1 pt). Tumor lysis was seen in the pt with the WBC count of 207 K/µL. Eighteen pts (7 too early) are evaluable for response. Responses are as follows: 6 CR, 3 nPR, 3 PR, and 6 with stable disease. Three pts have progressed at 18.8, 14.1 and 3.2 months after starting the study treatment; 2 pts had unmutated IGHV gene (FISH negative) and one pt had trisomy 12 (IGHV mutation status unknown). None of the pts with deletion 17p or deletion 11q have progressed. All pts are alive at this time. The median overall follow up time is 7.6 months (range, 1-28). Conclusions Ofatumumab is well tolerated in pts with early stage CLL and may delay time to first chemoimmunotherapy. Disclosures: Ferrajoli: GlaxoSmithKline: Research Funding.


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