Study on the mechanism of circular permuted tumor necrosis factor-related apoptosis-inducing ligand reversing the resistance to imatinib in chronic myeloid leukemia cells / 白血病·淋巴瘤

Objective:To explore the mechanism of circular permuted tumor necrosis factor-related apoptosis-inducing ligand (CPT) reversing the resistance to imatinib in chronic myeloid leukemia (CML) cells.Methods:Five patients with CML in the Affiliated Hospital of Inner Mongolia Medical University from 2016 to 2020 were selected, and heparinized bone marrow blood samples were collected at the first diagnosis and imatinib resistance phase, and mononuclear cells were isolated. The mononuclear cells collected at the first diagnosis were named A1-E1, and the mononuclear cells collected after imatinib resistance were named A2-E2. Human CML wild-type K562 cell line (K562-W) was given gradually increasing small doses of low-concentration imatinib to obtain imatinib-resistant K562 cells (K562-R). K562-R cells were cultured with 20 μg/L CPT and these cells were set as CPT-K562-R group. The CCK-8 method was used to detect the half inhibitory concentration ( IC50) of cells for imatinib. K562-W and K562-R cells were used to establish CML xenografts nude mice models, then the nude mice were divided into K562-W, K562-R and CPT-K562-R xenograft groups. Imatinib was perfused orally in all three groups, and CPT was injected subcutaneously in the CPT-K562-R group at the same time. The tumor volume of the three groups of nude mice before and 4 weeks after treatment with imatinib, and the survival time of the three groups of nude mice were compared. Western blot was used to detect the changes of tyrosine protein kinase receptor B4 (EphB4) and myeloid cell leukemia protein 1 (Mcl-1) protein levels in bone marrow mononuclear cells, K562 cell line and transplanted tumor tissues of CML patients. Results:The expressions of EphB4 protein in A2-E2 cells of 5 patients with CML were higher than those in A1-E1 cells (all P < 0.01). The IC50 of K562-W, K562-R and CPT-K562-R cells for imatinib were (0.160±0.015) mg/L, (5.450±0.460) mg/L, (0.300±0.035) mg/L, and the difference was statistically significant ( F = 390.65, P < 0.01). In cells of K562-W group, EphB4 and Mcl-1 proteins were expressed at low levels (0.54±0.02 and 0.70±0.08); in cells of K562-R group, the expressions of EphB4 and Mcl-1 proteins were enhanced (3.04±0.11 and 2.88±0.04); in cells of CPT-K562-R group, the expressions of EphB4 and Mcl-1 proteins decreased (0.57±0.03 and 0.38±0.04). Before imatinib treatment, there was no statistically significant difference in the tumor volumes of nude mice among the K562-W, K562-R and CPT-K562-R xenograft groups ( F = 0.39, P = 0.68), suggesting the transplanted tumors formed in nude mice were balanced; after imatinib treatment, the difference in the tumor volumes among the three groups were statistically significant ( F = 26.16, P < 0.01). The survival time of nude mice in the K562-W, K562-R and CPT-K562-R xenograft groups was (18.5±3.3) d, (10.0±2.4) d and (17.5±1.6) d, and the difference was statistically significant ( F = 20.45, P < 0.01). In K562-W xenograft group, both EphB4 and Mcl-1 proteins were expressed at low levels (0.55±0.06 and 0.67±0.06); in K562-R xenograft group, the expressions of EphB4 and Mcl-1 proteins were enhanced (1.95±0.08 and 6.21±0.53); the expressions of EphB4 and Mcl-1 in CPT-K562-R xenograft group decreased (0.59±0.04 and 0.37±0.04) and were close to their expressions in K562-W xenograft group. Conclusion:CPT may enhance the sensitivity of CML to imatinib by inhibiting the expressions of EphB4 and Mcl-1, and this may be a targeted pathway for imatinib therapy.

Expression of neuron specific enolase in serum of remission patients with diffuse large B-cell lymphoma and its significance / 白血病·淋巴瘤

Objective To examine the expression of neuron-specific enolase (NSE) in patients with remission diffuse large B-cell lymphoma (DLBCL),and to explone its prognostic value.Methods Serum NSE values were mesured by electmchemilumineseence immunoassay in 20 health donors and 40 DLBCL patients reached remission after 6-8 cycles of chemotherapy after initial diagnosis.Results Positive expressions rate of NSE in remission DLBCL patients was 50 ％,and was 10 ％ in health donors (P ＜ 0.01).In remission DLBCL patients,there was significant difference in the 2-year PFS rate between in NSE-positive group and negative group (6.6 ％ vs 20.9％,P ＜ 0.001).Serum NSE was an independent poor prognostic factor in remission DLBCL patients.Conclusion Serum NSE expressions is an independent poor prognostic factor of remission DLBCL and has significant clinical value.

Homoharringtonine contributes to imatinib sensitivity in chronic myeloid leukemia cell lines / 中国肿瘤临床

Objective: To investigate the mechanism responsible for homoharringtonine (HHT), which contributes to imatinib (IM) sensitivity in the chronic myeloid leukemia (CML) cell line. Methods:We established cell lines from a patient with CML at the time of first diagnosis and relapse phase, and designated the cell lines as NPHA1 and NPHA2, respectively. Stable underexpressed EphB4 cells (NPHA2-EphB4-sh) were obtained. Leukemia cell lines were incubated with HHT. The activated signal proteins in cells were tested by Western blot. Results:EphB4 was overexpressed in IM-resistant NPHA2 compared with the NPHA1 cell line. However, the expression of EphB4 mRNA and protein were significantly decreased in knockdown NPHA2-EphB4-sh cells compared with the NPHA2 and NPHA1 (P<0.001) cell lines. NPHA2-EphB4-sh cells were sensitive to IM (IC50:0.93 mg/L), and NPHA2 showed IM re-sistance (IC50 : 5.45 mg/L) (P<0.001). However, co-stimulation with HHT+IM decreased IC50 of NPHA2 cells to 1.17 mg/L (P<0.001). Meanwhile, phospho-Rac1/cdc42 was significantly increased in NPHA2 cells compared with NPHA2-EphB4-sh (P<0.001). HHT blocked the expression of EphB4/RhoA. Conclusion: The overexpression of EphB4 contributed to IM resistance in CML line cells. EphB4/RhoA may be a new marker of IM resistance. HHT with IM yielded more treatment advantages than IM alone by blocking EphB4/RhoA pathways.

Identification of differentially expressed genes related to blastic crisis in chronic myeloid leukemia / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify differentially expressed genes between chronic phase and blast crisis in chronic myeloid leukemia, explore the mechanism and screen potential biomarkers of disease progression.</p><p><b>METHODS</b>The differences in the gene expression profiles of bone marrow mononuclear cells between chronic phase and blastic crisis were examined using DNA microarray. PANTHER database, Genomatix database and Bibliosphere software were used to analyze and predict the critical genes or transcription factors during disease progression. Some of the genes or transcription factors were selected for verification by semi-quantitative RT-PCR.</p><p><b>RESULTS</b>In blastic crisis, 68 of the 1176 tested genes were obviously up-regulated. Sixteen of these differential genes were selectively expressed in leukocyte membranes. CD40, CCR3, LGALS3, RGS3, CEACAM3 and the related transcription factors RAC1, CTNNB1, TP53, and NF-κB, all as the nodes of the entire regulatory network, were presumed to play key roles in disease progression. The results of RT-PCR were consistent with the microarray data and showed high expression of CEACAM3, RGS3, CTNNB1 and RAC1 in blastic crisis.</p><p><b>CONCLUSION</b>A group of genes have been identified to very likely play key roles or serve as biomarkers in the transition from the chronic phase to blastic crisis in chronic myeloid leukemia.</p>

Cytogenetic differences between adults and children with acute lymphoblastic leukemia: eight-probe fluorescence in situ hybridization and karyotype analyses / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the cytogenetic differences between children and adults with acute lymphoblastic leukemia (ALL) using eight-probe fluorescence in situ hybridization and karyotype analysis.</p><p><b>METHODS</b>Eight-probe (MYC, P16, E2A, TEL/AML1, BCR/ABL , MLL , IGH, and hyperdiploidy) fluorescence in situ hybridization and karyotype analysis were performed for 86 adults and 39 children with acute lymphoblastic leukemia.</p><p><b>RESULTS</b>Eight-probe fluorescence in situ hybridization showed significant differences in the positivity rate of TEL/AML1, BCR/ABL, and hyperdiploidy between adult patients and children with ALL. By karyotype analysis, the positivity rate of t(9;22) and hyperdiploidy differed significantly between the children and adult patients (P<0.05).</p><p><b>CONCLUSION</b>Adults and children with ALL have different expression profiles of the fusion genes. Eight-probe fluorescence in situ hybridization is time-saving, accurate and efficient in detecting common genetic abnormalities in ALL patients, and can be well complementary to karyotype analysis in clinical diagnosis of ALL.</p>