CLLU1 Gene Expression Level As a Prognostic Parameter in Patients with Chronic Lymphocytic Leukemia

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4603-4603
Author(s):  
Mustafa Sevinc ◽  
Ahmet Emre Eskazan ◽  
Aydin Karabulut ◽  
Suzin Catal Tatonyan ◽  
Emine Gulturk ◽  
...  

Abstract Abstract 4603 Background Chronic lymphocytic leukemia (CLL) is the most frequent leukemia in the Western world with an annual incidence of 5/100,000. The clinical course of the disease is highly variable; while some CLL patients experience a stable clinical course that will never affect their morbidity or mortality, some of them will eventually progress and require chemotherapy. In addition to the traditional prognostic markers (e.g. Rai and Binet staging systems), more recently, mutational status of the variable regions of the immunoglobulin heavy chains (IgVH), chromosomal aberrations, CD38 expression and Zeta-chain-associated protein kinase 70 (ZAP-70) expression are used to better determine the prognosis in CLL patients. A novel CLL-specific gene, CLL Up-regulated gene 1 (CLLU1) that uniquely overexpressed in CLL patients, was recently demonstrated. It has been shown that CLLU1 mRNA expression levels in CLL patients predict time to initiation of therapy as well as overall survival (OS), and CLLU1 is highly up-regulated in poor-risk groups. The aim of this study is to investigate the relationship between CLLU1 levels and well known prognostic parameters and, to determine the importance of CLLU1 gene on prognosis and clinical course in our CLL patients. Methods 116 (46 female, 70 male) CLL patients who consecutively visited our outpatient clinic between May 2009 and March 2010 were enrolled in the study. Median age was 60 years (range, 30–87 years). Blood samples were drawn from the patients for CLLU1 determination, and CLLU1 levels were determined by RT-PCR method. CLLU1 expression level was counted both in CLL patients and healthy B cells as the difference between CLLU1 and abl (taken as an house keeping gene) gene. Then, they are transformed as folds which is the ratio between CLLU1 level in CLL patients and that in healthy B cells. Patients with CLLU1 expression exceeding the CLLU1 expression of normal (CD19+) B-cells were taken as positive. Each patient was followed for at least one year for survival data. For the statistical analysis, student’s t-test, Mann-Whitney U test and Pearson correlation were used. p<0.05 was considered as statistical significant. The study was approved by the local research ethics committee, and written informed consent was obtained from the patients. Results There was no relationship between CLLU1 levels and, sex, age, modified RAI and BINET stages, lymphocyte counts and LDH levels at the time of diagnosis. Patients with nodular bone marrow infiltration had lower CLLU1 levels than patients with non-nodular infiltration (57.6 vs 498). Patients with high β2 microglobulin levels had higher CLLU1 levels than the ones with low β2 microglobulin levels (356.7 vs 13.6, p<0.05). ZAP-70 positive patients had higher CLLU1 levels than ZAP-70 negative patients (217.2 vs 10.2, p=0.007) (Figure 1). Among the patients with CD38 levels studied (n=53) CLLU1 levels were higher in patients with CD38 levels above the median value than patients with CD38 levels below the median value (438.4 vs 42.2). CLLU1 levels were higher in cases who needed treatment than cases without treatment. Patients with a shorter time to treatment had higher CLLU1 levels than patients with a longer time to treatment (p=0.028) (Figure 2). Conclusion With a limited number of patients we could demonstrate that CLLU1 levels correlated with β2 microglobulin levels and ZAP-70. Although there were similar findings also with CD38 levels; the association was not statistically significant due to the limited number of cases. Time to treatment was shorter in patients with CLLU1 levels above the median value than patients with CLLU1 levels below the median value. CLLU1 is a promising and specific new prognostic parameter in patients with CLL, and further studies in larger series are needed to define the impact of CLLU1 in the prognosis and clinical course of CLL patients. Disclosure This study was supported by Istanbul University Research Fund. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3132-3132
Author(s):  
Bryce Manso ◽  
Kimberly Gwin ◽  
Charla R Secreto ◽  
Henan Zhang ◽  
Wei Ding ◽  
...  

Abstract Peripheral immune dysfunction in B-Chronic Lymphocytic Leukemia (CLL) is well-studied and likely relates to the incidence of serious recurrent infections and second malignancies that plague CLL patients. However, the current paradigms of known immune abnormalities are not able to consistently explain these complications and it is not easy to correct CLL patient immune status. Here, we expand on our preliminary reports that demonstrate bone marrow (BM) hematopoietic dysfunction in early and late stage untreated CLL patients. We found reduced short-term functional capacity of hematopoietic progenitors in BM using colony forming unit assays (Figure 1A-C) and flow cytometry revealed significant reductions in frequencies of hematopoietic stem and progenitor cell (HSPC) populations (exemplified by Lin-CD34+ HSPCs, Figure 1D). We further report that protein levels of the transcriptional regulators HIF-1α, GATA-1, PU.1, and GATA-2 are overexpressed in distinct HSPC subsets from CLL patient BM, providing molecular insight into the basis of HSPC dysfunction. Interestingly, sustained myelopoiesis, evaluated by limiting dilution analysis in long-term culture-initiating cell (LTC-IC) assays maintained for five weeks, revealed no difference between healthy controls and CLL patients. These new data indicate that when HSPCs are removed from the leukemic microenvironment for ample in vitro culture time, they recover the ability to sustain myelopoiesis. To further assess the impact of the CLL microenvironment on HSPC biology, isolated HSPCs (CD34+ BM cells) from healthy controls were exposed in vitro to known leukemic microenvironment constituents. Exposure to TNFα, a cytokine constitutively produced by CLL B cells, resulted in rapid increases in PU.1 and GATA-2 proteins (Figure 2A-D). Similarly, addition of TNFα to the LTC-IC assay resulted in a striking ablation of myelopoiesis, even at the highest input cell concentration. Further, overexpression of PU.1 and GATA-2 were observed in HSPCs following co-culture with CLL B cells, a result that was not recapitulated when cells were exposed to IL-10, another cytokine constitutively produced by CLL B cells. These findings indicate specific components of the leukemic microenvironment are involved in HSPC modulation. Together, these findings expand on our previous observations of BM hematopoietic dysfunction in untreated CLL patients and offer new molecular insights into the contribution of the leukemic microenvironment on immunodeficiency in CLL. Disclosures Ding: Merck: Research Funding. Parikh:Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Janssen: Research Funding; Abbvie: Honoraria, Research Funding; Gilead: Honoraria; AstraZeneca: Honoraria, Research Funding. Kay:Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 695-695
Author(s):  
Lukas P. Frenzel ◽  
Alexandra Schulz ◽  
Christian P. Pallasch ◽  
Rainer Claus ◽  
Sabine Ponader ◽  
...  

Abstract Abstract 695 We recently identified the transmembrane protein TOSO to be significantly over-expressed in chronic lymphocytic leukemia (CLL) compared to other B-cell lymphomas or healthy B-cells and T-cells. TOSO was initially characterized as inhibitor of Fas-mediator of apoptosis; however, it could be demonstrated to be the receptor for the IgM-specific Fc-domain in immune cells. TOSO is the only Fcμ receptor expressed on B-cells and is solely expressed in the lymphoid compartment. However, little is known on its regulation and the molecular background of over-expression in CLL. We investigated TOSO expression on mRNA and protein level in freshly isolated primary CLL cells (n=10) and healthy B-cells (n=4) after single treatment for 24 hours with a comprehensive panel of different cytokines or stimuli (interleukin (IL)-1, IL-2, IL-4, IL-6, IL-7, IL-10, IL-12, IL-15, interferon (IFN)-γ, transforming growth factor (TGF)-ß, tumor necrosis factor (TNF)-α, lipopolysaccharide, CpG, CD40-ligand (CD40L) and B-cell receptor (BCR)) being involved in B- and T-cell interplay, by qRT-PCR, western blotting and flow cytometry. Furthermore, we determined the impact of nurse-like cells (NLC) to TOSO expression and co-incubated primary CLL cells for up to 14 days with NLCs. To better understand the intracellular regulation of TOSO, we inhibited BCR and/or CD40L pathways, which were shown by us to be either stimulatory (BCR) or inhibitory (CD40L) in regard to TOSO expression. Since expression might be finally also controlled on epigenetic level, we determined the methylation status of the putative TOSO promoter in 64 CLL samples and 10 healthy B-cells samples. Quantitative DNA methylation analysis was conducted using the EpiTyper application by Sequenom (San Diego, CA, USA). Our experiments reveal novel extra- and intracellular stimuli regulating TOSO expression. We identified CD40L, IL-4 and CpGs to have strong inhibitory effects on TOSO expression (P<0.001) in primary CLL cells and healthy B-cells. In contrast, we identified NLCs (MFIR 15,8 vs. 25,8; P=0.049; n=4) and BCR cross-linking to induce TOSO expression on the cell surface of CLL cells. Based on extracellular stimuli, we were able to hypothesize on shared downstream pathways in order to identify the key regulatory factors and transcription factors controlling TOSO expression. By using a panel of inhibitors in BCR and CD40L downstream signaling, NF-kappa B was shown to have the strongest effect on TOSO expression (P=0,0294). Applying the I-kappa B kinase (IKK) inhibitor Wedelolactone at non-toxic concentrations (10μM), TOSO expression was profoundly suppressed after 24 hours. Regarding epigenetic alterations, our analysis from genome-wide screening experiments in CLL patients compared to healthy B-cells did reveal significant aberrant DNA de-methylation events in the TOSO promoter-associated CpG island (P<0.001). In conclusion, we revealed IL-4, CpG and CD40L as BCR stimulus and NLCs as the key components in regulation of TOSO in the CLL cell microenvironment. Furthermore, over-expression of TOSO in CLL cells compared to normal B-cells could be demonstrated being associated with epigenetic changes at its promoter. We identified TOSO as a novel NF-kappa B regulated target gene. In ongoing studies we elucidate whether NF-kappa B acts directly or in-directly on TOSO expression. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2830-2830
Author(s):  
Stefania Gobessi ◽  
Sara Bennardo ◽  
Pablo G Longo ◽  
Brendan Doe ◽  
Dimitar G Efremov

Abstract Abstract 2830 The protein tyrosine kinase ZAP-70 is an important prognostic factor in chronic lymphocytic leukemia (CLL). Patients that are considered ZAP-70-positive typically express 30–100% of the levels of ZAP-70 in T-cells, whereas in the remaining patients ZAP-70 is either not expressed or is expressed at lower levels. ZAP-70-positive patients have more aggressive disease and shorter survival than patients with low or absent ZAP-70. In vitro experiments with human lymphoma cell lines and primary CLL B-cells have shown that ZAP-70 is involved in B cell receptor (BCR) signaling, indicating that overexpression of ZAP-70 could affect the capacity of the leukemic cells to respond to antigen stimulation. Despite the strong association between ZAP-70 expression and prognosis, it is still not clear whether ZAP-70 directly contributes to the aggressiveness of the disease or is just a marker of more aggressive CLL. To further address this issue, we generated transgenic (tg) mice that express different levels of ZAP-70 in B cells. In these mice expression of the murine ZAP-70 transgene is targeted to the B cell compartment by a VH or a CD19 promoter (VH-ZAP70 and CD19-ZAP70 tg mice, respectively). B cells in CD19-ZAP70 tg mice express the same levels of ZAP-70 as normal murine T cells, whereas the levels of ZAP-70 in B cells of VH-ZAP70 tg mice are approximately 10 times lower. Immunophenotyping analysis of spleen and peritoneal cavity samples from wild type, VH-ZAP70 and CD19-ZAP70 tg mice did not reveal significant differences in the percentage of follicular (FO), marginal zone (MZ) and B1 B cells, indicating that ectopic expression of ZAP-70 does not affect normal B cell development and maturation. In terms of BCR signal transduction, no abnormalities were detected in VH-ZAP70 tg mice, suggesting that low levels of ZAP-70 do not affect BCR signaling. In contrast, B cells from CD19-ZAP70 tg mice showed altered phosphorylation of several molecules downstream of the BCR, such as Syk and BLNK, whereas phosphorylation of Cbl was not affected. To investigate the impact of ZAP-70 expression on leukemia development and progression, we crossed VH-ZAP70 and CD19-ZAP70 tg mice with Eμ-TCL1 tg mice. The latter mice develop leukemias that are considered a mouse model of human CLL. These leukemias are CD5+, express unmutated IGHV genes and stereotyped polyreactive BCRs, but are always ZAP-70-negative. VH-ZAP70/Eμ-TCL1 tg mice (n=11) have been followed for over a year and did not show any differences with respect to their Eμ-TCL1 littermates (n=10). Both groups, starting from the age of 7–8 months, developed leukemias with a similar rate of progression and impact on survival, suggesting that low levels of ZAP-70 do not affect the behavior of the disease. The cohort of CD19-ZAP70/Eμ-TCL1 tg mice was more recently established. These animals are currently 4 months old and still do not show signs of leukemia development. Data from the extended follow-up of these mice will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 642-648 ◽  
Author(s):  
C Rozman ◽  
E Montserrat ◽  
JM Rodriguez-Fernandez ◽  
R Ayats ◽  
T Vallespi ◽  
...  

Abstract In previous studies, the prognostic value of bone marrow (BM) histologic patterns in chronic lymphocytic leukemia (CLL) has been demonstrated. In order to investigate whether such a value is independent of other prognostic parameters, a multivariate survival analysis (Cox's regression model) was undertaken in a series of 329 CLL patients in whom a BM had been performed. The following binary variables were included in the analysis: age (more than 60 years), lymphadenopathy (more than two areas involved), splenomegaly, hepatomegaly, absolute lymphocyte count (more than 30,000 microL), anemia (hemoglobin less than 10 g/dL), thrombocytopenia (less than 100,000 microL), and BM pattern (diffuse v nondiffuse). Three variables entered the regression at significant level: BM pattern (P less than .001), anemia (P less than .001), and hepatomegaly (P = .03). The model was also tested by expressing the variables in a continuous way when possible. Again, BM pattern entered first in the regression (P less than .001), followed by the hepatomegaly (P = .002), hemoglobin level (P = .02), and lymphadenopathy (P = .04). When both the binary and the continuous models were tested separately in 227 patients with BM as initial staging procedure and in 102 patients in whom this was performed later during the course of the disease, in all instances, BM pattern entered first in the regression at a highly significant level. BM histologic pattern appears to be a better single prognostic parameter than any one of the variables employed in current clinical staging systems. A combined clinicopathologic system incorporating the BM pattern, together with the usual clinical variables, is presented.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3281-3281
Author(s):  
Renee C. Tschumper ◽  
Tait D. Shanafelt ◽  
Neil E. Kay ◽  
Diane F. Jelinek

Abstract BACKGROUND: Chronic lymphocytic leukemia (CLL) is a heterogeneous B cell malignancy with patients being categorized into disease subsets based on several key biologic parameters, e.g., mutation status (mutated, M; or unmutated, UM) of the immunoglobulin heavy chain variable region (IGHV), acquired chromosomal abnormalities, and expression of CD38 and CD49d. Furthermore, about one third of CLL patients express stereotyped B cell receptors and/or may acquire high risk common mutations in genes such as NOTCH1 and SF3B1 suggesting ongoing genetic evolution as drivers of disease development. Critical to this concept, those CLL patients with trisomy 12 (T12) defects have a higher incidence of mutations in NOTCH1 and often have a stereotyped receptor. However, T12 patients may have a variable clinical course that appears to be unrelated to these 2 drivers suggesting an additional, possibly non-coding genetic component that may further impact disease progression in these patients. One potentially relevant genetic factor that could influence T12 clinical course is long non-coding RNAs (lncRNAs). LncRNAs are transcripts longer than 200 nucleotides that can affect a number of cellular processes. Importantly, lncRNAs have been implicated in various cancers including malignant hematopoiesis indicating they could be therapeutic targets and/or clinically useful biomarkers. METHODS: To pursue a role for lncRNAs in T12 we used v3.0 Arraystar Human LncRNA Microarrays to assess the global profile of lncRNA expression in CLL with an emphasis on patients with T12. Two cohorts of 6 patients with T12 were selected for comparison: one defined as progressive with a short time to treatment (TTT) (treatment ≤1 year after diagnosis) and one as indolent (no treatment > 5 years after diagnosis). Each cohort included 3 patients with M and 3 with UM IGHV status. RNA from normal CD5+ and CD5- B cells was included as a control. To compensate for the small sample size in each cohort, a significant difference in lncRNA expression between the groups was defined as a fold change (FC) ≥5.0, p-value ≤0.05 and false discovery rate (FDR) ≤ 0.05. RESULTS: An initial global comparison of CD5+/CD5- normal B cells vs all CLL samples found that 609 lncRNAs were differentially expressed using the criteria listed above with 158 lncRNAs having a FC>10. Notable lncRNAs in this group included: LOC541472 (down in CLL and associated with the IL-6 gene), D63785 (up in CLL and associated with TBC1D3C, an oncoprotein), CTC-459I6.1 (up in CLL and associated with RASGRF2) and AC002480.5 (down in CLL and associated with STEAP1B, shown to be overexpressed in prostate cancer). We next evaluated T12 samples and identified 90 candidate lncRNAs that may discriminate between progressive and indolent T12 cases. Within this group were 11 lncRNAs with a FC > 10, 5 of which have no known associated gene. Of those associated with known genes, 3 were ultra-conserved region encoding lncRNAs down-regulated in progressive T12 patients (TTT ≤1 yr) and linked to hephaestin-like protein 1 precursor, pannexin-1, and tubulin beta-3 chain isoform 1. Of potential high relevance we found that the lncRNA LPP-AS1 was down-regulated in progressive T12 patients (TTT ≤1 yr) and known to be associated with the LIM-containing lipoma preferred partner (LPP) gene (p=0.028; FDR=0.03 and FC=18.3). Looking specifically at IGHV M progressive T12 patients (T12M≤1 yr) vs IGHV M indolent T12 patients (T12M>5 yrs), we again found the LPP-AS1 lncRNA was highly down-regulated in T12M≤1 (p=0.00046; FDR=0.006 and FC=34.5) but it was not found to be differentially expressed in the UM T12≤1 yr vs UM T12>5 yr comparison. The LPP gene has been shown to play a role in cell-cell adhesion, motility and signaling, and is often the fusion partner for the mixed lineage leukemia (MLL) gene in secondary acute leukemia. Furthermore, LLP may play a role in breast cancer cell invasion. LPP-AS1 may be participating in IGHV M T12 progression by affecting LPP and thus influencing migration through the lymph node microenvironment. CONCLUSION: While candidate lncRNAs in T12 CLL need to be validated, the LPP-AS1 lncRNA shows promise as a possible marker and potential treatment target for those patients with T12 and M IGHV that may progress rapidly. Further studies are needed to evaluate the impact of lncRNAs on clinical outcome of T12 CLL patients. Disclosures Shanafelt: Hospiria: Research Funding; Pharmacyclics/Jannsen: Research Funding; Cephalon: Research Funding; Celgene: Research Funding; glaxoSmithKline: Research Funding; Genetech: Research Funding; Polyphenon E Int'l: Research Funding. Kay:Celgene: Research Funding.


Blood ◽  
2004 ◽  
Vol 104 (3) ◽  
pp. 788-794 ◽  
Author(s):  
Yean K. Lee ◽  
Nancy D. Bone ◽  
Ann K. Strege ◽  
Tait D. Shanafelt ◽  
Diane F. Jelinek ◽  
...  

AbstractWe recently reported that chronic lymphocytic leukemia (CLL) cells synthesize and release vascular endothelial growth factor (VEGF) under normoxic and hypoxic conditions. CLL B cells also express VEGF membrane receptors (VEGF-R1 and VEGF-R2), suggesting that they use VEGF as a survival factor. To assess the mechanism of apoptosis resistance related to VEGF, we determined the impact of VEGF on CLL B cells, and we studied the impact of epigallocatechin-3-gallate (EGCG), a known receptor tyrosine kinase (RTK) inhibitor, on VEGF receptor status and viability of CLL B cells. VEGF165 significantly increased apoptotic resistance of CLL B cells, and immunoblotting revealed that VEGF-R1 and VEGF-R2 are spontaneously phosphorylated on CLL B cells. EGCG significantly increased apoptosis/cell death in 8 of 10 CLL samples measured by annexin V/propidium iodide (PI) staining. The increase in annexin V/PI staining was accompanied by caspase-3 activation and poly–adenosine diphosphate ribose polymerase (PARP) cleavage at low concentrations of EGCG (3 μg/mL). Moreover, EGCG suppressed the proteins B-cell leukemia/lymphoma-2 protein (Bcl-2), X-linked inhibitor of apoptosis protein (XIAP), and myeloid cell leukemia-1 (Mcl-1) in CLL B cells. Finally, EGCG (3-25 μg/mL) suppressed VEGF-R1 and VEGF-R2 phosphorylation, albeit incompletely. Thus, these results suggest that VEGF signaling regulates survival signals in CLL cells and that interruption of this autocrine pathway results in caspase activation and subsequent leukemic cell death.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4947-4947
Author(s):  
Menna Hodge ◽  
Susan O’Brien ◽  
Adam Abdool ◽  
Michael Keating ◽  
Iman Jilani ◽  
...  

Abstract &lt;/DEL&gt; CD5, a transmembrane protein expressed in T-cells, few B-cells, and chronic lymphocytic leukemia (CLL) B-cells, is the ligand for CD72 and may play a role in B-cell-T-cell communication. CD5 is part of the T-cell receptor (TCR)-CD3 complex in T-cells as well as the B-cell receptor (BCR) complex and serves as substrate for induction of tyrosine kinase activity. Since leukemic cells have high turnover and pour their protein, RNA, and DNA into the circulation, we speculated that free circulating CD3 (cCD3) and CD5 (cCD5) could be detected in the plasma of patients with CLL. We have developed a bead-based sandwich immunoassay to measure cCD3 and cCD5 in the plasma. Using this assay, we assessed the value of cCD5 measurement, alone and after normalization to cCD3 levels, as a tumor marker in CLL. Plasma levels of cCD3 and cCD5 were measured in 85 patients with CLL and 51 normal control subjects. cCD3 and cCD5 levels were significantly higher in patients with CLL (median, 7,465 and 55,806 U/μl, respectively) than in normal control subjects (median, 830 and 1,671 U/μl, respectively). Patients with CLL had significantly higher cCD5:cCD3 ratios (median, 5.28; range, 0–161) than did normal controls (median, 1.70; range, 0–8.06) (P &lt;0.0001). Levels of cCD5, but not cCD3, correlated positively with WBC count, β2-microglobulin level, splenomegaly, and Rai stage (all P &lt;0.01). The cCD5:cCD3 ratio also correlated with Rai stage (P = 0.04) and β2-microglobulin level (P = 0.03). cCD5 levels and the cCD5:cCD3 ratio both correlated with survival (P = 0.03). These findings confirm that free circulating surface markers can be detected in the circulation of patients with CLL, most likely reflect the tumor load, and can be used as tumor markers. The biological and therapeutic relevance of these free circulating proteins should be considered in pharmacokinetic and pharmacodynamic studies.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2853-2853
Author(s):  
Aleksandra Butrym ◽  
Miroslaw Majewski ◽  
Justyna Dzietczenia ◽  
Tomasz Wrobel ◽  
Kazimierz Kuliczkowski ◽  
...  

Abstract Abstract 2853 B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in adults in western countries. It is characterized by B lymphocyte accumulation in peripheral blood, bone marrow, lymph nodes and other lymphatic organs. Leukemic cells derive most commonly from B lymphocytes, rarely from T or NK cells. B-CLL is known from its heterogeneous clinical course from indolent to very aggressive. In spite of many known prognostic factors (such as immunoglobulin heavy chain gene mutational status – IgVH, expression of ZAP70 and CD38), is still difficult to classify a single patient to particular risk group and to predict CLL clinical course. That is why new prognostic factors are still needed. HS1 (hematopoietic cell specific Lyn substrate-1) is an intracellular protein, which expression occurs mainly in hematopoietic cells. HS1 plays an important role in regulating T cell immune synapse and affects many functions of NK cells, including the lysis of target cells, adhesion, chemotaxis and clustering of actin in the lytic synapse. The role of HS1 in B cells is poorly understood. This protein was identified in B cells as the primary receptor substrate for phosphorylation by BCR after antigenic stimulation. Other studies have confirmed the role of HS1 in the process of clonal expansion and deletion induced by antigen-receptor interaction in B cells and T. HS1 is rapidly phosphorylated in B cells in the vicinity of tyrosine residues and is a substrate for tyrosine kinases: the Src family and Syk, including Lyn, FGR, Fyn and Lck. It has been shown that HS1 interacts with the cell cytoskeleton in both: normal and leukemic B cells. HS1 protein is an important regulator of motility, migration and adhesion of leukemic cells and is involved in cytoskeleton rearrangement. HS1 can have impact on homing and migration of CLL cells. It can indirectly promote disease progression and influence patient survival. The aim of this study was to evaluate HS1 expression in CLL patients in connection with other known prognostic factors and patient survival. Material and methods: 92 untreated CLL patients (45 women and 47 men), aged between 42 and 88 years (median age 67 years), were included into the study. Diagnosis was made basing on typical clinical, hematological and immunophenotypical picture. The control group was consist of 28 healthy matched people (11 men and 17 women), aged between 36 and 79 years (median age 59 years). HS1 protein expression was determined by western blot. Comparative semi-quantitative indication of the degree of saturation of the bands analyzed by densitometry using the gel documentation system Gel-Doc (Bio-Rad) and a computer program to analyze the 1-D Quantity One (Bio-Rad). Assuming conventional units [AU - arbitrary units], depending on the saturation band, patients were divided into four groups with the expression of HS1 protein expressed in value from 0 to 3. Lack of expression was expressed as 0 [AU], and expression of the strongest, with the highest saturation band measured as 3 [AU]. Mutational status of IgVH, as well as CD38 and ZAP70 expression were also analyzed. Results: HS1 expression was significantly higher in CLL patients comparing to controls. Positive correlation was shown between HS1 and: age (p=0.0454), Rai stage (p=0.0412), leukocytosis (p=0.0129) and β2-microglobulin (p=0.0342). There was negative correlation between HS1 and hemoglobin level (p=0.0464) and platelet count (p=0.0310). Patients with lymphocyte doubling time shorter or equal to 6 months had higher expression of HS1. Expression of HS1 significantly influenced survival of CLL patients. Patients with higher HS1 expression had shorter survival than those with lower HS1 expression (p=0.0329). Conclusions: 1. Higher HS1 expression is observed in more advanced CLL stages. 2. Expression of HS1 in CLL cells is matched with shorter patient survival The relationship between expression of HS1 and survival of patients with B-CLL. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 11 ◽  
Author(s):  
Stefano Baldoni ◽  
Beatrice Del Papa ◽  
Filomena De Falco ◽  
Erica Dorillo ◽  
Carlo Sorrentino ◽  
...  

NOTCH1 mutations and deregulated signal have been commonly found in chronic lymphocytic leukemia (CLL) patients. Whereas the impact of NOTCH1 mutations on clinical course of CLL has been widely studied, the prognostic role of NOTCH1 activation in CLL remains to be defined. Here, we analyzed the activation of NOTCH1/NOTCH2 (ICN1/ICN2) and the expression of JAGGED1 (JAG1) in 163 CLL patients and evaluated their impact on TTFT (Time To First Treatment) and OS (Overall Survival). NOTCH1 activation (ICN1+) was found in 120/163 (73.6%) patients. Among them, 63 (52.5%) were NOTCH1 mutated (ICN1+/mutated) and 57 (47.5%) were NOTCH1 wild type (ICN1+/WT). ICN1+ patients had a significant reduction of TTFT compared to ICN1-negative (ICN1−). In the absence of NOTCH1 mutations, we found that the ICN1+/WT group had a significantly reduced TTFT compared to ICN1− patients. The analysis of IGHV mutational status showed that the distribution of the mutated/unmutated IGHV pattern was similar in ICN1+/WT and ICN1− patients. Additionally, TTFT was significantly reduced in ICN1+/ICN2+ and ICN1+/JAG1+ patients compared to ICN1−/ICN2− and ICN1−/JAG1− groups. Our data revealed for the first time that NOTCH1 activation is a negative prognosticator in CLL and is not correlated to NOTCH1 and IGHV mutational status. Activation of NOTCH2 and JAGGED1 expression might also influence clinical outcomes in this group, indicating the need for further dedicated studies. The evaluation of different NOTCH network components might represent a new approach to refine CLL risk stratification.


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