Objective To observe the efficacy of imatinib on the treatment of bcr-abl positive essential thrombocythemia (ET). Methods A case of bcr-abl positive ET resistant to hydroxyurea (HU) treating with imatinib (200～400 mg/d) was reported and related literatures were reviewed. Results A case of bcr-abl positive ET was initially treated with 1.5～2.0 g/d HU, the platelet count decreased to 562x109/L after 4 weeks; however, the platelet count increased to (1020～1330)×109/L treating with same dose of HU 16 months later. With the elevation of HU to 3.0 g/d, platelet count was still high(1290～1780)x109/L companied with the very low white blood cell count(0.3～0.9)×109/L. While treating with imatinib (400 mg/d) for 1 month,the platelet count decreased to 390×109/L and white blood cell count was 0.5×109/L; Furthermore, treating with 200×300 mg/d of imatinib, the platelet and white blood cell count recovered in normal after 1 month,and bcr-abl fusion gene negative 2 months later. Conclusion Imatinib may be the effective targeting drug for the bcr-abl positive ET, and the bcr-abl positive ET is sensitive to low dose imatinib.

Objective To investigate the efficacy of imatinib combining with allogeneic hematopioetic stem cell transplantation or chemotherapy for bcr-abl positive acute lymphoblastic leukemia (ALL). Methods 12 cases were diagnosed on morphology, cytochemistry, immunophenotype and bcr-abl fusion gene. The induction is imatinib (400 mg/d) combining chemotherapy. 8 cases accepted allogeneic hematopoietic stem cell transplantation after complete remission (CR). If bcr-abl became positive, the patient was treated with imatinib (400～600 mg/d). 3 cases were tested with imatinib alternating chemotherapy after cr. Results 11 patients gained CR, CR rate 91.7 %; 5 patients (41.7 %) became bcr-abl negative through 2 courses induction. 3 cases relapsed after transplantation. 2 cases relapsed in imatinib combining chemotherapy group. The median remission interval is 16 months (imatinib combining transplantation group) and 10 months (imatinib combining chemotherapy group) (P <0.01) respectively. The median survival time is 18 months (imatinib combining transplantation group), and the other group (imatinib combining chemotherapy) is 12 months (P <0.01). Conclusion Imatinib combining chemotherapy achieved high CR rate for the bcr-abl positive ALL. Imatinib combining allogeneic hematopoietic stem cell transplantation is superior to imatinib combining chemotherapy for CR patients.

Objective To investigate the inhibitional effect of MRPI-shRNA on expression of MRP1gene in K56.2/AS2 cells resistant to arsenic trioxide. Methods Three pieces of MRPI-shRNA were designed,synthesized and transfected into K562/AS2 cells with lipesome. Expression level of MRPI mRNA were determined by real time fluorescent quantitative PCR. MRPI protein expression and intracellular accumulation of DNR were assayed with flow cytometry. Results After treated with MRPI-shRNA, the expression level of MRPI mRNA and MRPI protein in K562/AS2 cells decreased significantly(79.1±0.07) % and (62.48±0.86) %,respectively (P <0.05). The intracellular accumulation of DNR increased significantly(P < 0.05). Conclusion MRPI-shRNA can down-regulate the expression of MRPI gene in K562/AS2 cell line.

Objective:To investigate the therapeutic effect of venetoclax combined with azacitidine in treatment of myelodysplastic syndromes (MDS) complicated with monoclonal globulinemia of unknown significance (MGUS).Methods:The clinical data of a patient with MDS complicated with MGUS in the Second People's Hospital of Shenzhen in December 2020 were retrospectively analyzed, and the literatures were reviewed.Results:According to results of bone marrow smear, cytogenetics, and next-generation sequencing, the patient was diagnosed as MDS and MGUS complicated with ASXL1, RUNX1, EZH2, STAG2 mutations as well as t(11;14). No response was observed after 2 courses of azacitidine and 1 course of azacitidine plus HAG. Later the patient achieved complete remission and negative RUNX1 and STAG2 mutations after a course of venetoclax combined with azacitidine. Meanwhile, M protein exhibited a decrease more than 50%. To date, the patient was still in complete remission.Conclusions:The regimen of venetoclax combined with azacitidine shows a significant efficacy and good tolerance to patient with co-occurrence of MDS and MGUS with t(11; 14).

Objective:To evaluate the efficacy and safety of azacitidine combined with HAG regimen in the treatment of newly diagnosed elderly acute myeloid leukemia (AML) patients ineligible for intensive chemotherapy.Methods:Eighteen newly diagnosed elderly AML patients ineligible for intensive chemotherapy from July 2019 to September 2021 in the Second People's Hospital of Shenzhen were prospectively enrolled in this study. They were non-randomly divided into azacitidine combined with HAG regimen (AZA-HAG) group (9 cases) and decitabine combined with HAG regimen (DEC-HAG) group (9 cases). The primary endpoint of the study was overall response [complete remission (CR)+partial remission], and the secondary endpoints included CR + complete remission with incomplete count recovery (CRi), overall survival (OS) and drug safety. Kaplan-Meier method was used to analyze the OS.Results:The median age of 18 patients was 67 years old (60-77 years old) , and 8 of them were in high-risk group. After one course of treatment, the overall response and CR+CRi were observed in 7 of 9 patients in AZA-HAG group, and they were observed in 8 of 9 patients in DEC-HAG group, and there was no significant difference between the two groups (both P = 1.000). The median duration of CR+CRi was 7 months in both groups, and the median OS time was 12 months in both groups; there was no significant difference in OS between the two groups ( χ2 = 0.02, P = 0.895). In AZA-HAG group, 1 patient with TP53 mutation and 1 patient with ASXL1+RUNX1 mutation acquired CR, and 1 patient with NPM1 wild-type combined with FLT3-ITD and ASXL1 mutation did not respond. There was no significant difference in the incidence of grade 3-4 hematological adverse reactions between the two groups (all P < 0.05). Conclusions:Azacitidine combined with low-dose HAG regimen in the treatment of newly diagnosed elderly AML patients ineligible for intensive chemotherapy has satisfactory efficacy and long-term survival, and the adverse reactions can be tolerated.