RESUMEN
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.
RESUMEN
BACKGROUND: The structural and functional changes in resistance arteriole of external diameter ＜300 μm is one of the pathological foundations for ischemic cerebrovascular diseases, however there are few quantitative study on the arterioles of various external diameter at different brain area.OBJECTIVE: To probe the difference of arteriolar sclerosis of various external diameter at different brain area after cerebral infarction.DESIGN: Sample investigation.SETTING: Department of Nerve Internal Medicine, General Hospital of Beijing Military Area Command of Chinese PLA.SUBJECTS: Specimen was taken from donated autopsy case in General Hospital of Beijing Military Area Command of Chinese PLA from January 1980 to September 2000. According to the clinical manifestation, brain CT inspection and pathological diagnosis of autopsy, 38 cases were defined as arteriosclerosis cerebral infarction and taken as experimental group, other 15 cases with non-cardiac cerebrovascular disease were taken as controls.METHODS: specimen was obtained in 1-3 days after death from frontal and parietal cerebral cortex and basal gonglion white matters (3 pieces /case) and cut into slices. Five fields of vision were selected from each slice for microscopic observation. Arteriole was divided into ＜ 50 μm group,50-100 μm group and ＞100 μm group according to the arteriole external diameter. (External diameter- internal diameter)/internal diameter was used to assess vascular sclerosis.MAIN OUTCOME MEASURES: [1] Difference of arteriole sclerosis between corresponding external diameter cerebral infarction group and control group. [2] Arteriole sclerosis in various brain region in cerebral infarction group.RESULTS: Totally 38 experimental cases died from arteriosclerosis cerebral infarction and 15 controls died from non-cardiac cerebrovascular disease were enrolled and all data was entered the result analysis. [1] The arteriolar sclerosis index was obviously higher in ＜ 50 μm external diameter cerebral infarction group than in 50-100 μm group and ＞100 μm group[(138.55±76.67)% vs (116.82±58.80)%, (78.07±32.06)%, P ＜ 0.01], while it was approximately the same in the 100 μm external diameter group and control group [(78.07±32.06)% vs (46.38±13.41)%, P=0.174 ]. [2] In ＜ 50 μm external diameter cerebral infarction group, the arteriolar sclerosis index in white matters was significantly higher than that in gray matter [(152.86±87.83)%,(127.97±64.76)%, P ＜ 0.05 ].CONCLUSION: Arteriolar sclerosis degree is correlated with its external diameter and position in patients with cerebral infarction after arteriosclerosis, arteriole of small external diameter or in the white matter has higher arteriolesclerosis liability.