TOSO interacts with SYK and enhances BCR pathway activation in chronic lymphocytic leukemia / 中华医学杂志(英文版)

BACKGROUND@#TOSO, also named Fas inhibitory molecule 3 (FAIM3), has recently been identified as an immunoglobulin M (IgM) Fc receptor (FcμR). Previous studies have shown that TOSO is specifically over-expressed in chronic lymphocytic leukemia (CLL). However, the functions of TOSO in CLL remain unknown. The B-cell receptor (BCR) signaling pathway has been reported to be constitutively activated in CLL. Here, we aimed to investigate the functions of TOSO in the BCR signaling pathway and the pathogenesis of CLL.@*METHODS@#We over-expressed TOSO in B-cell lymphoma cell lines (Granta-519 and Z138) by lentiviral transduction and knocked down TOSO by siRNA in primary CLL cells. The over-expression and knockdown of TOSO were confirmed at the RNA level by polymerase chain reaction and protein level by Western blotting. Co-immunoprecipitation with TOSO antibody followed by liquid chromatography coupled with tandem mass spectrometry (IP/LCMS) was used to identify TOSO interacting proteins. Western blotting was performed to detect the activation status of BCR signaling pathways as well as B-cell lymphoma 2 (BCL-2). Flow cytometry was used to examine the apoptosis of TOSO-over-expressing B lymphoma cell lines and TOSO-down-regulated CLL cells via the staining of Annexin V and 7-AAD. One-way analyses of variance were used for intergroup comparisons, while independent samples t tests were used for two-sample comparisons.@*RESULTS@#From IP/LCMS, we identified spleen tyrosine kinase (SYK) as a crucial candidate of TOSO-interacting protein and confirmed it by co-immunoprecipitation. After stimulation with anti-IgM, TOSO over-expression increased the phosphorylation of SYK, and subsequently activated the BCR signaling pathway, which could be reversed by a SYK inhibitor. TOSO knockdown in primary CLL cells resulted in reduced SYK phosphorylation as well as attenuated BCR signaling pathway. The apoptosis rates of the Granta-519 and Z138 cells expressing TOSO were (8.46 ± 2.90)% and (4.20 ± 1.21)%, respectively, significantly lower than the rates of the control groups, which were (25.20 ± 4.60)% and (19.72 ± 1.10)%, respectively (P < 0.05 for both). The apoptosis rate was reduced after knocking down TOSO in the primary CLL cells. In addition, we also found that TOSO down-regulation in primary cells from CLL patients led to decreased expression of BCL-2 as well as lower apoptosis, and vice versa in the cell line.@*CONCLUSIONS@#TOSO might be involved in the pathogenesis of CLL by interacting with SYK, enhancing the BCR signaling pathway, and inducing apoptosis resistance.

Clinical analysis of 70 chronic lymphocytic leukemia patients with trisomy 12 detected by FISH / 中华血液学杂志

Objective: To summarize and investigate the characteristics, prognosis and treatments of chronic lymphocytic leukemia (CLL) patients with trisomy 12 by using FISH (CEP12). Methods: Clinical data of 330 CLL patients were analyzed retrospectively by using FISH (CEP12) to detect trisomy 12 from May 2003 to April 2015. The clinical data and laboratory characteristics of CEP12 positive patients (70 cases) were compared with those CEP12 negative patients (260 cases). Results: Compared with CEP12 negative CLL patients, the proportion of hepatomegaly (13.6% vs 4.0%, P=0.011) and LDH>247 U/L (43.3% vs 18.5%, χ(2)=15.892, P<0.001) in CEP12 positive CLL patients were much higher, respectively. There were no significant differences between age, sex, clinical stage, β(2)-microglobulin level, IGHV mutation ratio and splenomegaly/lymphadenopathy in these two subgroups. However, compared with CEP12 negative patients, CEP12 positive patients had higher ratio of FMC7 (23.8% vs 12.7%, χ(2)=4.730, P=0.030), and lower ratio of CD23 (95.2% vs 99.6%, P=0.033). The overall response rates (ORR) in Fludarabine (without Rituximab), Rituximab (with or without Fludarabine) and the traditional chemotherapy group (chlorambucil, CHOP or CHOP-like) were 77.5% (31/40), 84.8% (56/66) and 45.4% (50/110), respectively. The ORR of the traditional chemotherapy group was lower than that of the Fludarabine group and Rituximab group. For CEP12 positive patients, the ORR was inferior to CEP12 negative patients when only using Fludarabine (P<0.05). However, when using Rituximab, the difference could be eliminated, and the ORR was even a little higher in CEP12 negative patients (91.7% vs 81.0%, P=0.306). Compared with CEP12 negative patients, there were no significant differences in progression-free survival (PFS) (χ(2)=0.410, P=0.478) and overall survival (OS) (χ(2)=0.052, P=0.180) for CEP12 positive patients whom the median time from diagnosis to start treatment and OS time was 22.6 (95%CI 15.4-31.7) and 118.5 (95%CI 74.5-162.4) month while the 5-year PFS and OS were (52.9±7.6)% and (74.8±6.6)%. Conclusions: CEP12 positive CLL patients are more common in hepatomegaly and higher level of LDH. The traditional chemotherapy treatment had the lowest efficacy, and the curative effect of single use of fludarabine is not as good as that of CEP12 negative patients, however, when using Ritaximab, the efficacy could be comparable.

Effect of Myeloma-Derived Exosomes on Surface Activating Receptors of NK Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of myeloma-derived exosomes on surface activating receptors of NK cells, and to explore the mechanism of the function defect of NK cells.</p><p><b>METHODS</b>The exosomes from the supernatant of multiple myeloma cell lines RPMI8226 and U266 were extracted by ultracentrifugation, and the size of them was identified under electron microscope; the human primary NK cells were extracted, and were co-cultured with the myeloma-derived exosomes (40 µg/ml), then the expression levels of surface activating receptors NKp46, NKp30 and NKG2D of NK cells at 0,1,4 and 24 hours were detected by flow cytometry.</p><p><b>RESULTS</b>The exosomes showed small vesicular, sized 30-100 nm under electron microscope. The expression of surface activating receptors of NK cells declined at different degree after co-cultured with myeloma-derived exosomes.</p><p><b>CONCLUSION</b>Myeloma-derived exosomes can inhibit the expression of surface activating receptors of NK cells.</p>

Efficacy of Rituximab for Patients with Chronic Lymphocytic Leukemia / 中国医学科学院学报

Objective To evaluate the efficacy of rituximab in treating chronic lymphocytic leukemia (CLL). Methods The clinical data of CLL patients receiving fludarabine,cyclophosphamide±rituximab (with or without rituximab) regimen or cyclophosphamide,vincristine,and prednisone±doxorubicin±rituximab regimen in our hospital from March 2000 to February 2015 were analyzed retrospectively. Therapeutic efficacies and survivals of patients treated with different regimens were evaluated and compared. Results The complete response (CR) rate and the overall response rate (ORR) in 72 patients (43.6%) treated with rituximab were significantly higher than those treated without rituximab (38.9% vs. 21.5%,P=0.015;83.3% vs. 60.2%,P=0.001). The median PFS and OS for patients treated with rituximab were 53.0 (27.0-79.0) months and 112.0 (81.1-142.9) months,and the median PFS and OS for patients treated without rituximab were 28.0 (18.3-37.7) months and 89.0(72.0-106.0),but the results were not statistically significant (P=0.094,P=0.109). According to the cytogenetic features,patients were further divided into high-risk subgroup (with chromosome 17p deletion or 11q deletion) and non-high-risk subgroup. And in the high-risk subgroup,the ORR of patients treated with rituximab was 86.4%,which was significantly higher than that in patients treated without rituximab (53.3%)(P=0.012);in the non-high-risk subgroup,the PFS was marginally prolonged in patients treated with rituximab,but the difference was not statistically significant(P=0.050). Conclusions Compared with traditional chemotherapy,the chemoimmunotherapies with rituximab result in higher CR rate and ORR in CLL patients. In patients without 17p deletion or 11q deletion,the use of rituximab can marginally prolong PFS.

Chronic Lymphocytic Leukemia Prognostic Index: A New Integrated Scoring System to Predict the Time to First Treatment in Chinese Patients with Chronic Lymphocytic Leukemia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The established clinical staging systems (Rai/Binet) of chronic lymphocytic leukemia (CLL) cannot accurately predict the appropriate treatment of patients in the earlier stages. In the past two decades, several prognostic factors have been identified to predict the outcome of patients with CLL, but only a few studies investigated more markers together. To predict the time to first treatment (TTFT) in patients of early stages, we evaluated the prognostic role of conventional markers as well as cytogenetic abnormalities and combined them together in a new prognostic scoring system, the CLL prognostic index (CLL-PI).</p><p><b>METHODS</b>Taking advantage of a population of 406 untreated Chinese patients with CLL at early and advanced stage of disease, we identified the strongest prognostic markers of TTFT and, subsequently, in a cohort of 173 patients who had complete data for all 3 variables, we integrated the data of traditional staging system, cytogenetic aberrations, and mutational status of immunoglobulin heavy chain variable region (IGHV) in CLL-PI. The median follow-up time was 45 months and the end point was TTFT.</p><p><b>RESULTS</b>The median TTFT was 38 months and the 5-year overall survival was 80%. According to univariate analysis, patients of advanced Rai stages (P < 0.001) or with 11q- (P = 0.002), 17p- (P < 0.001), unmutated IGHV (P < 0.001), negative 13q- (P = 0.007) and elevated lactate dehydrogenase levels (P = 0.001) tended to have a significantly shorter TTFT. And subsequently, based on multivariate Cox regression analysis, three independent factors for TTFT were identified: advanced clinical stage (P = 0.002), 17p- (P = 0.050) and unmutated IGHV (P = 0.049). Applying weighted grading of these independent factors, a CLL-PI was constructed based on regression parameters, which could categorize four different risk groups (low risk [score 0], intermediate low [score 1], intermediate high [score 2] and high risk [score 3-6]) with significantly different TTFT (median TTFT of not reached (NR), 65.0 months, 36.0 months and 19.0 months, respectively, P < 0.001).</p><p><b>CONCLUSIONS</b>This study developed a weighted, integrated CLL-PI prognostic system of CLL patients which combines the critical genetic prognostic markers with traditional clinical stage. This novel modified PI system could be used to discriminate among groups and may help predict the TTFT and prognosis of patients with CLL.</p>

Divergence Analysis of Hepatitis Virus Infection between Aggressive and Indolent B Cell Non-Hodgkin's Lymphoma / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence rate of hepatitis B virus(HBV)and hepatitis C virus(HCV)between aggressive and indolent B cell non-Hodgkin's lymphoma (B-NHL), and to compare the different infection rate of Hepatifis Virus between the 2 groups.</p><p><b>METHODS</b>Integrated clinical information of 733 newly diagnosed indolent B-NHL patients and 148 aggressive B-NHL patients from January 1994 to January 2014 was retrospectively analyzed. The difference of hepatitis virus infection was compared between the 2 groups.</p><p><b>RESULTS</b>The positive rate of HCV-Ab was 1.8% in 881 newly diagnosed B-NHL patients. The HCV prevalence was 1.9% and 1.35% in the indolent and aggressive B-NHL group respecitvely. Compared with general population, the HCV positive rate was significantly higher in the whole B-NHL group and the indolent group(1.8% vs 0.4%,1.9% vs 1.4%)(P<0.01), while it was not significantly different in the aggressive group (1.35% vs 0.4%)(P=0.068). The positive rate of HCV-Ab was not significantly different between the indolent and the aggressive group (1.9% vs 1.35%)(P=0.639). The HBs-Ag positive rate in the whole B-NHL group was 9.0%, which was significantly higher than that in the general population (9.0% vs 7.2%)(P<0.05). The positive rate of HBs-Ag in the indolent and aggressive B-NHL group was 7.9% and 14.2%, respectively. It was significantly higher in the aggressive group than that in the indolent one (14.2% vs 7.2%)(P<0.01). Compared with the general population, the aggressive group had significantly higher prevalence rate of HBV. However, it was not significantly different between the indolent group and the general population (7.9% vs 7.2%)(P>0.05).In the aggressive B-NHL group,the co-expression of HBs-Ag,HBe-Ag and anti-HBc-Ab was 4.4%, which was higher than that in the indolent one (4.7% vs 1.2%)(P<0.01). However, compared with the indolent group, the co-expression of HBs-Ag, anti-HBe-Ab and anti-HBc-Ab was not significantly different in the aggressive group (5.5% vs 6.1%)(P>0.05).</p><p><b>CONCLUSION</b>The HCV is more relevant with indolent B-NHL, the HBV has more relevance with the aggressive patients.</p>

Analysis of Clinical Curative Efficacy for 91 Cases of Splenic Marginal Lymphoma / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the clinical characteristics, treatment and prognosis of splenic marginal zone lymploma (SMZL).</p><p><b>METHODS</b>A total of 91 cases of SMZL admitted in our hospital from January 2002 to March 2013 were enrolled in this study. The clinical characteristics and immunophenotypes were summarized, and the clinical therapeute response and prognostic factors were analyzed statistically.</p><p><b>RESULTS</b>The median age of 91 patients was 56 (28-79); all the patients displayed splenomegaly with 73.6% of large spleen, hepatomegaly (14.6%) and lymphadenophathy (28.2%); the bone marrow involvement was observed in 98.9% patients, the B symptom was found in 47.1% patients. The positive expression of CD20 was observed in 100% patients, the positive expression of CD5 was in 8.3% patients, the positive expression of CD23 was found in 47.6% patients, no specific antigen was observed by now for SMZL. The clinical treatment showed that total ORR was 87.7%, CRR was 53.8% in chemotherapy group, chemotherapy combined with rituximab showed a better response than that of chemotherapy alone, which ORR was 100%, CRR was 72.4%, the difference between them was statistically significant. The Hb < 120 g/L, elevated LDH level and treatment without rituximab were the poor prognostic factors for PFS, while the elevated LDH level was related with OS of patients.</p><p><b>CONCLUSION</b>The patients with SMZL often display splenomegaly, involvement in bone marrow and absence of specific immunophenotypes. Chemotherapy combined with rituximab can definitely improve the outcome of SMZL. The Hb level, LDH level and treatment combined with or without rituximab seem to be related to the prognosis of the disease.</p>