[Clinical Effect of Tyrosine Kinase Inhibitors in the Treatment of P230 Chronic Myeloid Leukemia].

OBJECTIVE: To observe the curative efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of e19a2 transcript (P230) CML chronic phase (CML-CP) patients. METHODS: The clinical data of 11 P230 CML-CP patients were collected from July 2008 to December 2019. Blood routine examination, bone marrow cytology, chromosome, and BCR-ABL qualitative and quantitative tests were performed at initial diagnosis. After TKIs treatment, BCR-ABL (P230)/ABL in peripheral blood was regularly detected to evaluate molecular response by real-time quantitative PCR. RESULTS: There were 11 patients (7 males and 4 females) in chronic phase from 6 domestic hospitals enrolled, their median age was 46 years old (range from 19 to 56 years old). Among 4 patients treated with imatinib (400 mg, qd) firstly, 3 cases switched to nilotinib (400 mg, bid) and 1 case switched to dasatinib (100 mg, qd) due to failure to achieve best molecular response at the landmark time or mutation of ABL kinase. Then major molecular response (MMR) was obtained within 1 year. In addition, 5 patients were treated with nilotinib (300 mg, bid) and 2 patients with dasatinib (100 mg, qd) as first-line treatment, all of them got MMR within 6 months. CONCLUSION: For intolerance or resistance to imatinib, second-generation TKIs can enable P230 CML patients to achieve deeper molecular response, and MMR in a short time.

[Effect of Regulating A20 Expression on NF-κB Expression and Biological Characteristics of Jurkat Cells].

OBJECTIVE: To explore the effect of regulating A20 expression on NF-κB and biological characteristics of Jurkat cells with glucocorticoid (GC) resistance. METHODS: CCRF CEM and Jurkat cells were treated with dexamethasone (DEX) at concentrations of 100、10、1、0.1、0.01 and 0.001 µmol/L, and cultured for 24、48 and 72 h. The proliferation inhibition rate of Jurkat cell was detected by CCK-8. A20 plasmid was constructed, A20-siRNA was designed and synthesized, and transfected into Jurkat cells by liposome. CCK-8 was used to detect the proliferation rates of Jurkat cells in different concentrations of DEX group, DEX combined with A20 plasmid group and A20-siRNA group. The mRNA expression level of NF-κB was detected by RT-qPCR, the protein expression level of NF-κB was detected by Western blot, and the apoptosis of Jurkat cells was examined by flow cytometry. RESULTS: The inhibitory effects of DEX at different concentrations on the growth of CCRF CEM cells were time-dependent (r=0.984, P＜0.05) and concentration-dependent (r=0.966, P＜0.05). At the point of 24 hour, the IC50 approached 1 µmol/L in CCRF CEM cells. Great large differences began to appear between 1 and 10 µmol/L, the proliferation rate of Jurkat cells treated with 1 µmol/L DEX did not show a significant change. Therefore, 1 µmol/L was selected as control group. The cell proliferation rate of A20 plasmid transfection combined with different concentrations of DEX group was lower than that of DEX group and A20-siRNA combined with DEX group. After transfection of A20 plasmid, the expression level of NF-κB was significantly lower than that of control group (P＜0.05), and the apoptotic rate was significantly higher than that of control group (P＜0.05). After transfection of Jurkat cells with A20-siRNA, the expression level of NF-κB was significantly higher than that of control group (P＜0.05). The apoptotic rate of cells in A20-siRNA group was not significantly changed (P＞0.05). CONCLUSION: Jurkat cells are resistant to DEX. A20 overexpression combined with DEX can increase sensitivity of Jurkat cells with GC resistance and decrease the proliferation rate of Jurkat cells, down-regulate the expression level of NF-κB and promote the apoptosis of Jurkat cells.