Recent Research Advances on Signaling Pathway in B-cell Malignancy - Review / 中国实验血液学杂志

B-cell malignancy, a kind of malignant tumor of blood system, is characterized by heterogeneity and complexity of the pathogenesis. In this review, the recent advances of studies on B-cell malignancy and signaling pathways are briefly summarized. This review focuses on the role of signaling pathways, especially the NF-κ B, Wnt, PI3K/Akt, Notch and JAK/STAT signaling pathway in the occurrence and development of B-cell malignancy, and discussed the influence of signaling pathways on the invasiveness and drug resistance of B-cell malignancy, and the clinical application of signaling pathway inhibitors.

Expression of Notch Gene and Its Role of Anti-apoptosis and Drug-resistance of Cells in Chronic Lymphocytic Leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of Notch gene in chronic lymphocytic leukemia cells and to explore the change of Notch protein after the therapy with cytosine arabinoside or dexmethasone, and the mechanism of Notch mediated anti-apoptosis and drug-resistance in chronic lymphocytic leukemia cells.</p><p><b>METHODS</b>The mononuclear cells from bone marrow or peripheral blood of chronic lymphocytic leukemia patients (24 cases) and healthy donors (14 cases) were collected, then the expression of Notch gene, BCL-2, as well as NF-κB gene were detected by real-time fluorescent quantitative PCR (qRT-PCR) at the level of transcription. The change of Notch protein in L1210 cell lines after therapy with cytosine arabinoside and dexmethasone was determined by Western blot.</p><p><b>RESULTS</b>mRNA expression levels of Notch1, Notch2, BCL-2 and NF-κB gene in CLL group were significantly higher than those in healthy control group (0.8556 ± 0.8726 vs 0.6731 ± 0.5334, P = 0.0182; 1.2273 ± 0.8207 vs 0.6577 ± 0.6424, P < 0.0001; 8.0960 ± 7.5661 vs 0.5969 ± 0.4976, P < 0.0001; 1.0966 ± 0.6925 vs 0.5373 ± 0.7180, P < 0.0001, respectively), but no significant difference was found between Notch3 and Notch4 gene (1.1914 ± 2.4219 vs 0.8713 ± 0.7937, P = 0.3427; 0.8174 ± 1.0869 vs 0.9752 ± 1.3446, P = 0.2402, respectively). Notch1 protein expression in L1210 cells were significantly decreased after treating with cytosine arabinoside of low and middle concentrations, but increased after treating with cytosine arabinoside of high concentration or prolonging time of cytosine arabinoside of middle con-centration. Notch1 protein expression in L1210 cells dereased after treating with dexamethasone, but did not be changed with the different concentrations and different times of dexmethason.</p><p><b>CONCLUSION</b>The transcription level of Notch gene in CLL patients significantly higher than that in normal controls. The Notch1 protein expression is down-regulated in process of inhibiting L1210 cell proliferation by Ara-C and dexmethason. Notch signaling pathway may mediated anti-apoptosis and drug resistance of CLL cells. Notch molecule possibly plays an important role in the anti-apoptosis and drug-resistance of CLL cells.</p>

Notch signal pathway and chronic lymphocytic leukemia / 中国实验血液学杂志

Chronic lymphocytic leukemia (CLL), an indolent B-cell malignancy, is characterized by heterogeneity of the clinical course. Notch signaling pathway is an evolutionarily conserved signaling pathway and involved in the normal regulation of cell survival, proliferation, differentiation, apoptosis and other physiological processes. In recent years, more and more researchers study the relationship between Notch signaling pathway and chronic lymphocytic leukemia and have found that Notch molecules present in CLL cells with high expression or mutation, which associated with the prognosis, anti-apoptosis, drug-resistance and so on. In this article, the recent advances of studies on CLL and Notch pathway, including the expression level of Notch molecules in CLL cells, the anti-apoptosis and drug-resistance of Notch molecules in CLL cells, the mutation of Notch molecules in CLL cells, the relation of Notch molecules with CLL prognosis and the application prospect of Notch molecule inhibitors are reviewed.

A case of Richter syndrome transformed from chronic lymphocytic leukemia with karyotype aberration of trisomy 12 / 中国实验血液学杂志

This study was aimed to investigate the relationship between Richter's syndrome (RS) transformation and clinical characteristics as well as karyotype of patient with chronic lymphocytic leukemia (CLL). By the follow-up of a patient with CLL, the clinical characteristics, karyotype, treatment pattern and its effect, as well as disease progression were monitored regularly with serological test, flow cytometry and FISH technique. The results indicated that the patient typically presented with history of CLL at initial diagnosis, with expression of CD5(+), CD19(+) and CD23(+), Binet stage C, as well as karyotype aberration of trisomy 12, and poorly responded to 4 cycles of standard chemotherapy of FCR regimen. The disease progression was confirmed at 5 months with the symptoms of fever in the absence of infection, elevated lactate dehydrogenase level and rapidly enlarging lymphnodes which showed typically diffuse large B cell lymphoma by the biopsy. It is concluded that karyotype aberration of trisomy 12 is one of the risk factors for RS transformation, and treatment pattern of the patient with CLL may be associated with the transformation of RS.

Clinical analysis on 40 patients with chronic lymphocytic leukemia / 中国实验血液学杂志

This study was aimed to analyze the clinical and laboratorial characteristics of patients with chronic lymphocytic leukemia (CLL), as well as their relationship with outcomes of patients. The clinical and laboratorial data of 40 CLL patients admitted from 2004 to 2010 in our hospital were analyzed retrospectively. The results indicated that the most of CLL attacked the elderly male patients with median age 66 (from 42 to 80). Flow cytometric analysis showed that 25 cases were positive for typical immunophenotype of CLL. On the other hand, all the patients clearly expressed CD19 and CD5, 7 cases (17.5%) and 14 cases (35%) were positive for the expression of CD38 and Zap70 respectively. 8 cases harbored a mutated immunoglobulin heavy-chain (VH) gene, among them 4 cases belong to VH3 family. Interphase FISH analysis showed that P53 deletion, RB1 deletion, trisomy 12 and normal chromosome were detected in 6, 3, 1, and 5 cases, respectively. The median PFS in 31 patients received treatment of fludarabine based chemotherapy was 48 months (95%CI: 39 - 57 months), among them 27 cases (87.1%) achieved CR + PR. While PFS was 14 months (95%CI: 10 - 18 months, P < 0.001) in 9 patients received other treatment regimen, out of them only 3 cases (33.3%) achieved CR + PR. Patients with normal level of serum β2-microglobulin at diagnosis showed significantly higher overall survival (78%, 95%CI: 69% - 87%) in 36 months than those with abnormal level of serum β2-microglobulin (47%, 95%CI: 35% - 59%, P = 0.004). Significant difference in the rate of CR + PR was noted in the Zap70 positive group (50%) and in negative group (88.5%, P = 0.006). All of 8 patients with IgVH mutation displayed CR after treatment, while 4 cases (66.7%) archived CR among 6 patients without IgVH mutation. It is concluded that CLL is characterized by high heterogeneity in both clinical features and molecular markers, which are associated with prediction of outcomes for patients. The treatment with fludarabine-based chemotherapy results in a major benefit and long survival for patients with CLL.