[Clinical Characteristics and Prognosis of Patients with Primary Testicular Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To analyze the clinical manifestations, therapeutic response and prognosis of patients with primary testicular diffuse large B-cell lymphoma (PT-DLBCL). METHODS: Thirty-eight patients with PT-DLBCL were enrolled, who hospitalized from January 2010 to April 2021, and their clinical characteristics, treatment regimen and efficacy were collected and analyzed retrospectively. RESULTS: The median age of the patients was 56 years old (ranged from 38 to 79 years). There were 4 cases (10.5%) with bilateral lesions, 13 cases (34.2%) with left lesions, and 21 cases (55.3%) right lesions. There were 2 cases(5.3%) with B symptoms, 6 cases (15.8%) of germinal center B-cell-like(GCB) subtype and 32 cases(84.2%) of non-GCB subtype. Efficacy was evaluated in 36 cases, including 10 cases with CHOP regimen, 21 cases with R-CHOP regimen (7 cases were treated with rituximab combined with high-dose methotrexate injection chemotherapy at intervals of R-CHOP regimen), and 5 cases with other regimens. In 36 patients, the efficacy evaluation of initial chemotherapy showed that the overall response rate (ORR) was 86.1%, 29 cases (80.6%) reached complete response (CR), and 2 cases (5.5%) reached partial response (PR). The R-CHOP group was superior to CHOP group in ORR (95.2% vs 60.0%, P=0.027) and CR (90.4% vs 50.0%, P=0.022). Of the 36 patients, 7 cases had central nervous system(CNS) recurrence and 4 cases had contralateral testicular recurrence. Compared with the CHOP group, the CNS recurrence rate in the R-CHOP group was significantly lower (4.8% vs 50.0%, P=0.007), and the testicular recurrence rate in the R-CHOP group was also lower than the CHOP group, but the difference was not statistically significant (4.8% vs 30.0%, P=0.087). The median follow-up time was 27(3-135) months, and the 5-year PFS and OS were 71% and 74%, respectively. Kaplan-Meier univariate analysis showed that the R-CHOP regimen significantly improved the patients' PFS (P=0.024) and OS (P=0.025) compared with the CHOP regimen. CONCLUSION: PT-DLBCL is mainly treated with comprehensive treatment. Compared with CHOP regimen, R-CHOP regimen can improve the CR rate and ORR, reduce CNS recurrence and contralateral testicular recurrence, and improve the patients' survival. Patients may benefit from high-dose methotrexate combined with rituximab interlaced with R-CHOP regimen.

[Clinical Features of Diffuse Large B-Cell Lymphoma Transformed from Follicular Lymphoma].

OBJECTIVE: To analyze the clinical manifestations, pathological characteristics, therapeutic effect and prognosis of diffuse large B-cell lymphoma (DLBCL) transformed from follicular lymphoma (FL). METHODS: A total of 45 inpatients were eligible for criteria of histologic transformation from FL to DLBCL from January 2010 to January 2021, and their clinical characteristics, diagnosis, treatment and efficacy were collected and analyzed retrospectively. RESULTS: Among the 45 patients, transformation occurred at diagnosis in 27 cases, during " watch and wait " phase in 7 cases and after treatment of FL in 11 cases. The median age was 56 years old (ranged from 27 to 76 years), with 23 male and 22 female. The transformations were observed in 8 cases with low-grade and 37 cases with high-grade FL. Extranodal involvement was present in 26 cases, including bone marrow infiltration in 16 cases. There were 17 cases with anemia and 32 cases met the GELF criteria of high tumor burden. B symptoms were present in 12 cases. There were 38 cases with Ki-67≥50%. The germinal center B-cell-like (GCB) subtype of DLBCL was observed in 43 cases. Efficacy was evaluated in 45 cases. The OR, CR and PR rate were 80.0%, 60.0% and 20.0%, respectively. The OR,CR rate of patients received R-CHOP was higher than those of patients received other regimens (86.11% vs 55.55%, P=0.063; 66.67% vs 33.33%, P=0.126), but there was no significant statistical difference. The early transformation (at diagnosis) group showed the highest OR rate (85.18%) and CR rate (74.07%). The median follow-up time of all patients was 26 (4-120) months, and the median PFS (2-120 months) and median OS (5-120 months) had not yet reached. The 3-year PFS and OS were 55% and 70%, respectively. In univariate analysis, factors affecting PFS includ OR rate and POD24, and factors affecting OS includ IPI score, OR rate, POD24, B symptoms and anemia (P<0.05).Multivariant analysis indicated that OR rate and POD24 were the independent prognostic factors for PFS (P<0.05) and IPI score was an independent prognostic factor for OS (P<0.05). CONCLUSION: The OR and CR rates are higher in early transformation group of patients with DLBCL transformed from FL. Patients with anemia, B symptoms, POD24, and high-risk score have poor prognosis. IPI score is the independent prognosis factor for OS.

A real-world study of infectious complications of venetoclax combined with decitabine or azacitidine in adult acute myeloid leukemia.

PURPOSE: The purpose of this study was to identify the incidence, sites and main pathogens, and risk factors for infectious complications occurring in patients with adult acute myeloid leukemia (AML) during the first course of venetoclax combined with decitabine or azacitidine. METHODS: A retrospective cohort analysis was performed of 81 patients with AML older than 14 years who received the first cycle of venetoclax combined with a hypomethylating agent (HMA) between March 2018 and March 2021 at our institution. Infectious complications, if any, were documented. RESULTS: Among a total of 81 cases of AML, 59 (72.8%) patients occurred infections, including fever without an identifiable source (28.8%), clinically documented infections (40.7%), and microbiologically documented infections (30.5%). The most commonly isolated organism in culture was Candida albicans, followed by Klebsiella pneumonia, and Pseudomonas aeruginosa. The 4-week and 8-week mortality rates were 3.7% and 7.4%, respectively. In multivariate analysis, a high proportion of blasts in bone marrow, decreased hemoglobin level, and fever with or without a documented infection at baseline were significant independent risk factors for infectious complications. CONCLUSION: Compared with conventional chemotherapy, the incidence of infectious complications of venetoclax combined with decitabine or azacitidine significantly decreased. Pretreatment high leukemia burden and fever were independent risk factors for infections.

CDKN2A deletions are associated with poor outcomes in 101 adults with T-cell acute lymphoblastic leukemia.

The identification of genetic risk subgroups of T-cell acute lymphoblastic leukemia (T-ALL) may provide evidence for risk stratification and individualized treatment. We investigated the characteristics and prognostic value of tumor suppressor gene CDKN2A deletions in 101 patients with T-ALL. The CDKN2A deletion was present in 23% (23/101) of T-ALL by fluorescence in situ hybridization (FISH). The most common type of CDKN2A deletion was homozygous deletion (70%, 16/23). A lower frequency of CDKN2A deletion was found in patients with early T-cell precursor (ETP) ALL than in patients with non-ETP-ALL (10.4% vs 34.0%; P = .008). Deletion of CDKN2A was significantly associated with younger age (P = .001), higher white blood cell (WBC) count (P < .001) and higher lactate dehydrogenase (LDH) level (P = .002). Patients with CDKN2A deletion had lower 2-year overall survival (OS) and event-free survival (EFS) rates than patients without CDKN2A deletion (2-year OS: 18.6% ± 8.9% vs 47.4% ± 6.2%, P = .032; EFS: 16.4 ± 8.3 vs 38.6 ± 5.9%, P = .022). In multivariable analysis, CDKN2A deletion was an independent adverse prognostic factor for OS (P = .016). In conclusion, adult T-ALL patients with CDKN2A deletion had a poor prognosis, and these patients might benefit from intensive chemotherapy or allogeneic hematopoietic stem-cell transplantation.

Central nervous system leukemia in a patient with concurrent nasopharyngeal carcinoma and acute myeloid leukaemia: A case report.

RATIONALE: Concurrent case of nasopharyngeal carcinoma (NPC) and acute myeloid leukemia (AML) has not been reported. Here, we report a case of NPC, who was concurrently suffered from AML one mother after the NPC diagnosis. PATIENT CONCERNS: The patient was a 45-year-old male who presented with a mass on his right side neck. DIAGNOSES: The patient was diagnosed with Epstein-Barr virus negative type-2 non-keratinizing carcinoma with clivus involvement and unilateral metastasis to the cervical lymph node. INTERVENTIONS: He was treated with one cycle of cisplatin and 69.76 Gy of concurrent external-beam radiation. OUTCOMES: Three months after completion of chemo-radiotherapy, the patient was diagnosed as acute myeloid leukemia, which achieved complete remission after one course induction chemotherapy. Two months later, however, the patient was diagnosed as central nervous system leukemia. He ultimately died of relapsed leukemia. The overall survival of the patient was 10 months. LESSONS: The co-occurrence of NPC and AML is rare and prognosis is poor. Radiotherapy in NPC can disrupt the blood-brain barrier, which may contribute to the pathogenesis of central nervous system leukemia. Early alert and prevention of central nervous system leukemia following radiotherapy in NPC patient is recommended.

[Therapeutic Efficacy of VICP+L-ASP/TKI on Adult Patients with B-ALL].

OBJECTIVE: To evaluate the therapeutic efficacy of VICP+L-ASP/TKI on adult patients with B-ALL and to explore the influence factors. METHODS: Forty-one adult B-ALL patients treated with VICP+L-ASP/TKI from August 2008 to June 2014 were following-up. The complete remission(CR) rate, toxicity, overall survival(OS) and event free survival(EFS) after induction treatment were analyzed, the therapeutic outcome of patients between different risk stratification subgroups was compared, the influence of standardized consolidatory and maintaining treatment as well as allogeneic hematopoietic stem cell transplantation(allo-HSCT) on survival time was analyzed. RESULTS: The early death not occurred in 41 patients with B-ALL including 37 cases with CR; the CR rate of 1 course treatment was 90.2%. The follow-up time lasted to March 17, 2015, the median follow-up time was 25(9-79) months; the 1 year OS rate was 75.3%, the EFS rate was 58.3%. Analysis of risk factors showed that the initial WBC count over 30×109/L, LDH over 250 U/L and minimal residual disease(MRD) over 10-4 after treatment were poor prognostic factors. After remission, the standardized consolidatory treatment or allo-HSCT according to the "2012 China adult ALL diagnosis and treatment expert consensus" could improve long-term survival, 3 years OS rate was 73.8% and 61.5% respectively, 3 years EFS were 63.5% and 65.7% respectively. The main toxic and side effects were hematologic reactions, the hematologic adverse reaction of IV grade was observed in 97.6%(40/41) during induction treatment. CONCLUSION: Induction chemotherapy based on VICP+L-ASP/TKI and standardized consolidatory after remission according to the "2012 China adult acute lymphoblastic leukemia diagnosis and treatment expert consensus" can improve the therapeutic efficacy. The allo-HSCT should be actively performed for B-ALL paients with high risk(elevated initial WBC count and LDH level); at some time, the regularly monitoring MRD and adjusting therapeutic protocol according to monitoring result can promote the prognosis of adult B-ALL patients.

An Epistaxis Emergency Associated with Multiple Pollutants in Elementary Students.

Emergencies of epistaxis in students caused by environmental pollution have rarely been reported to date. This study aimed to explore the cause of an emergency of epistaxis in elementary students by using a field epidemiological investigation. Twenty-two epistaxis cases from a single school with differences in gender, age, and classroom, were diagnosed within a period of 7 days. The air concentration of chromic acid mist (Cr6+) in the electroplating factory area, new campus, and residential area exceeded the limit of uncontrolled emissions. The emission of HCL and H2SO4 was also observed. Formaldehyde levels in the classrooms exceeded the limits of indoor air quality. Abnormal nasal mucosa was significantly more frequent in the case group (93.3%) and control group 1 (of the same school) (66.7%) than in control group 2 (from a mountainous area with no industrial zone) (34.8%; P < 0.05 and P < 0.01, respectively). On the basis of the pre-existing local nasal mucosal lesions, excessive chromic acid mist in the school's surrounding areas and formaldehyde in the classrooms were considered to have acutely irritated the nasal mucosa, causing epistaxis. Several lessons regarding factory site selection, eradication of chemical emissions, and indoor air quality in newly decorated classrooms, should be learned from this emergency.

[Efficacy and safety of the HAA regimen as induction chemotherapy in 236 de novo acute myeloid leukemia].

OBJECTIVE: To evaluate the efficacy and safety of the HAA regimen (homoharringtonine, cytarabine and aclarubicin) as induction chemotherapy in de novo acute myeloid leukemia (AML). METHODS: The efficacy and safety of 236 de novo AML patients who received the HAA regimen as induction chemotherapy were retrospectively analyzed. The complete remission (CR) rate was assayed. Kaplan-Meier method was used to estimate overall survival (OS) and relapse free survival (RFS), and the differences were compared by Log-rank test. RESULTS: The overall CR rate was 78.0%, and 65.7% of the patients attained CR in the first induction cycle. The early death rate was 4.7%. The median followup time was 41(1-161) months. The estimated 5-year OS and 5-year RFS rates were 44.9% and 45.5%, respectively. The CR rates of patients with favorable, intermediate and unfavorable cytogenetics were 92.9%,78.6%and 41.7%, respectively. The 5-year OS of favorable and intermediate group were 61.1% and 45.1%, respectively. The 5- year RFS of favorable and intermediate group were 49.0% and 45.4%, respectively. The median survival time of unfavorable group was only 5 months. The side effects associated with the HAA regimen were tolerable, in which the most common toxicities were myelosuppression and infection. CONCLUSION: The HAA regimen is associated with a higher rate of CR and longer survival time and its toxicity could be tolerated.

[The efficacy and safety of HAA regimen as induction chemotherapy in 150 newly diagnosed acute myeloid leukemia].

OBJECTIVE: To explore the efficacy and safety of HAA regimen (homoharringtonine, cytarabine and aclarubicin) in the treatment of 150 newly diagnosed adult acute myeloid leukemia (AML). METHODS: All patients entered the study from May 1999 to June 2008 were treated with HAA regimen. Cox-survival analysis was used to estimate the survival rate and differences between M(1)/M(2) and M(4)/M(5) were compared with 2-sided log-rank test. RESULTS: Out of the 150 patients, 121 (81%) achieved complete remission (CR). After the first course, CR rate was 68%. The CR rates of 97%, 84% and 38% were achieved in patients with favorable, intermediate and unfavorable cytogenetics, respectively. For the patients with CR, the median follow-up time was 16.5 (1.5 - 100.5) months, and the estimated 3-year survival rate was 45%. The estimated 3-year relapse free survival rate was 52% for the 121 patients with CR. CONCLUSIONS: HAA regimen may be an efficacious and safe regimen with a good toleration in the induction therapy for newly diagnosed AML, and a high CR rate could be achieved with only one or two courses.

Novel influenza A (H1N1) in patients with hematologic disease.

Patients with hematologic disease are likely to be at increased risk for infection with influenza. We retrospectively analyzed 11 cases of patients with hematologic disease who were infected with pandemic H1N1 virus in our department, including their clinical manifestations, laboratory and imaging findings, outcomes of antiviral therapy, and factors associated with mortality. Notably, nine patients had lower respiratory tract disease. Five patients progressed to respiratory failure and eventually died, despite treatment with antivirals and/or corticosteroids and/or mechanical ventilation. We concluded that H1N1 2009 infection was associated with a severe course and high rate of mortality in patients with hematologic disease, and early diagnosis and antiviral treatment were important to reduce the rate of severe complications and mortality.

FLT3 and NPM1 mutations in Chinese patients with acute myeloid leukemia and normal cytogenetics.

Mutations of fms-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1) exon 12 genes are the most common abnormalities in adult acute myeloid leukemia (AML) with normal cytogenetics. To assess the prognostic impact of the two gene mutations in Chinese AML patients, we used multiplex polymerase chain reaction (PCR) and capillary electrophoresis to screen 76 AML patients with normal cytogenetics for mutations in FLT3 internal tandem duplication (FLT3/ITD) and exon 12 of the NPM1 gene. FLT3/ITD mutation was detected in 15 (19.7%) of 76 subjects, and NPM1 mutation in 20 (26.3%) subjects. Seven (9.2%) cases were positive for both FLT3/ITD and NPM1 mutations. Significantly more FLT3/ITD aberration was detected in subjects with French-American-British (FAB) M1 (42.8%). NPM1 mutation was frequently detected in subjects with M5 (47.1%) and infrequently in subjects with M2 (11.1%). FLT3 and NPM1 mutations were significantly associated with a higher white blood cell count in peripheral blood and a lower CD34 antigen expression, but not age, sex, or platelet count. Statistical analysis revealed that the FLT3/ITD-positive group had a lower complete remission (CR) rate (53.3% vs. 83.6%). Survival analysis showed that the FLT3/ITD-positive/NPM1 mutation-negative group had worse overall survival (OS) and relapse-free survival (RFS). The FLT3/ITD-positive/NPM1 mutation-positive group showed a trend towards favorable survival compared with the FLT3/ITD-positive/NPM1 mutation-negative group (P=0.069). Our results indicate that the FLT3/ITD mutation might be a prognostic factor for an unfavorable outcome in Chinese AML subjects with normal cytogenetics, while NPM1 mutation may be a favorable prognostic factor for OS and RFS in the presence of FLT3/ITD.

[Clinical study of amphotericin B in the treatment of invasive fungal infection in 111 hematological disorder patients with neutrocytopenia].

OBJECTIVE: To compare the differences in clinical therapeutic effect and safety between amphotericin B and its liposome form in treating invasive fungal infection (IFI) in hematological disorder with neutrocytopenia. METHODS: Of 111 patients with IFI, 82 were treated with amphotericin B and 29 with amphotericin B liposome. The mean cumulative dose of amphotericin B was 617 (60-1895) mg and the mean course was 18 (7-60) d, and those for amphotericin B liposome was 925 (140-3420) mg and 13 (7-50) d, respectively. RESULTS: The total effective rates of amphotericin B and its liposome groups were 69% and 58%, respectively (P>0.05). The adverse effect rates of chill and fever in amphotericin B and its liposome groups were 21% and 10% (P>0.05), hypopotassemia 34% and 14% (P=0.03), hepatic impairment 22% and 17% (P>0.05), and renal impairment 9% and 3%, respectively (P>0.05). CONCLUSION: The therapeutic effect for IFI of amphotericin B and its liposome was similar. The severe adverse reaction of amphotericin B liposome was slightly lower than that of amphotericin B.

[HAA regimen as induction chemotherapy for newly diagnosed acute myelogenous leukemia].

OBJECTIVE: To analyse the outcome of newly diagnosed adult acute myeloid leukemia (AML) patients treated with HAA (homoharringtonine, cytarabine and aclarubicin) regimen and explore the efficacy and safety of this regimen. METHODS: Eighty patients were treated with HAA regimen. The complete remission (CR) rate was observed. Kaplan-Meier method was used to estimate relapse free survival (RFS) rate and the differences were compared with 2-sided log-rank test. RESULTS: Of the 80 patients, 65 (81%) attained CR and the CR rate after the first course of induction was 75%. For the CR patients, the median follow-up was 26 (2 -69) months, and the estimated 3-year overall survival (OS) rate was 51% and the estimated 3-year RFS was 53%. For the AML-M5 and AML-M /M2 patients the CR rate was 74% and 87% and 3 year RFS of CR patients was 75% and 37%, respectively. The CR rate of 100%, 83% and 20% was achieved in patients with favorable, intermediate and unfavorable cytogenetics, respectively. The 3 year OS for favorable and intermediate group was 76% and 50% respectively. The median survival time of unfavorable group was only 6 months. CONCLUSION: HAA regimen is a safe, efficacious, and well-tolerable induction therapy for newly diagnosed AML.

Ankylosing spondylitis presenting with macrophage activation syndrome.

Macrophage activation syndrome (MAS), which can also be considered as reactive hemophagocytic syndrome (HPS), is a rare and potentially fatal complication of rheumatic diseases. We describe a 42-year-old woman in whom MAS developed as a complication of ankylosing spondylitis (AS). She suffered from fever and low back pain before admission. Laboratory findings were pancytopenia, abnormal liver enzymes, increased ferritin levels, and positive for B27. Hyperplasia of hemophagocytic macrophages was confirmed in her bone marrow. High-dose steroids therapy resulted in clinical and laboratory improvements. In this patient, there was no possible causative factor of HPS (such as viral infection, lymphoma, and systemic lupus erythematosus) except the presence of AS. There have been no previously reported cases describing the relationship between AS and HPS. This case indicates that attention should be given to the possibility that certain patients with AS-associated cytopenia may display accompanying intramedullary hemophagocytic phenomena.

Induction of apoptosis by homoharringtonine in G1 phase human chronic myeloid leukemic cells.

BACKGROUND: Homoharringtonine (HHT) is a cephalotaxine ester derived from an evergreen tree found wildely throughout southern China, which has antileukemic activities against a variety of acute myeloid leukemic cells. For the sake of illustrating the mechanisms of HHT in the treatment of leukemia, we assessed the effect of HHT on the apoptosis of human chronic myeloid leukemic cell line K562. METHODS: The apoptosis of K562 cells induced by HHT was analyzed by transmission electron microscopy, agarose gel electrophoresis of DNA, flow cytometry and terminal deoxyribonucleotidyl transferase-mediated dUTP-biotin nick labeling. RESULTS: Characteristic apoptosis-related features emerged in K562 cells after exposed to HHT at a concentration 0.05-100 microg/ml. Transmission electron microscopy of HHT treated K562 cells displayed chromatin condensation and aggregation under the nuclear membrane, nuclear fragmentation and apoptosis body formation. Typical DNA ladder in agarose gel electrophoresis was observed in the cells exposed to HHT. The cell cycle analysis measured by flow cytometry showed G1 phase cells decreased with the increase of S phase cells while apoptosis was induced by HHT in K562 cells. The percentage of apoptotic cells in K562 cells treated with 50 microg/ml of HHT decreased significantly when pretreated with 1 microg/ml of cycloheximide, 0.05 microg/ml of Actinomycin D respectively. CONCLUSIONS: HHT has apoptotic effects on K562 cells. The HHT induced apoptosis mainly of the cells in G1 phase and this process required RNA transcription and protein synthesis.

[Cytogenetic and clinical analysis of -7/7q- abnormalities in acute leukemia and myelodysplastic syndrome].

The objective was to study the incidence and prognosis significance of -7/7q- abnormalities in acute leukemia and myelodysplastic syndrome. Conventional cytogenetic analysis of R-band was used to test -7/7q- chromosome abnormalities in 410 patients with acute leukemia (AL), in 71 cases of myelodysplastic syndrome (MDS) and in 36 cases of chronic myelogenous leukemia in accelerated phase (CML-AP). The results showed that the incidences of -7/7q- abnormalities in AL, MDS and CML-AP patients were 4.88%, 9.86% and 8.33% respectively. The -7/7q- abnormalities could be found in acute myeloblastic leukemia (AML) and acute lymphocytic leukemia (ALL), incidences of which were 4.70% and 6.25% (P > 0.05) respectively. 9 cases had -7 or 7q- as the sole chromosome abnormalities, 22 cases showed other additional chromosome abnormalities: -X, -5, +8, t(3; 3), t(11;16) and t(2;11). Monosomy -7 and 7q- abnormality clone was found in one patient with MDS-RAEB, and the number of cells with -7 abnormality was greater than that of 7q- abnormality cells. Four patients acquired CR among 7 patients with ALL after chemotherapy, but 2 out of 13 patients with AML achieved CR while 6 out of 7 patients with MDS transformed into AL. No patients with CML-AP achieved CR. In conclusion, -7/7q- is a frequent aberration in hematologic malignancies as well as AML and ALL. The monosomy -7 and 7q-abnormalities were detected in the same patient. The patients with -7/7q- abnormalities show poor prognosis.

[Mechanisms of inhibitory effect of Ubenimex on human leukemic cells]

OBJECTIVE: To study the mechanism of inhibitory effect of Ubenimex on human leukemic cells. METHODS: K562 and HL60 cells were treated with Ubenimex at different concentrations, and the growth inhibition was analysed by MTT assay. Cell apoptosis was evaluated by light microscopy, agrose gel electrophoresis, TUNEL labeling method and flow cytometry (FCM) assay. RESULTS: (1)Treatment with Ubenimex remarkably inhibited the growth of HL60 cells, the IC(50) of Ubenimex for HL60 cells was 13.03&mgr;g/ml. But K562 cells were less sensitive than HL60. Ubenimex inhibited the growth of HL60 and K562 cells in a dose-dependent manner. (2)Apoptosis of leukemic cells was induced by Ubenimex, which was shown by the changes in morphology, DNA ladder on agrose gel, TUNEL labeling,typical peak before G1 phase of cell cycle and the positive of Annexin V(FITC) on the cells membrane with FCM. (3)Ubenimex induced apoptosis of K562 and HL60 cells in a dose-and-time-dependent manner. (4)The cell cycle analysis by FCM showed that the HL60 cells were blocked in G1 phase after treated by Ubenimex. Conclution Ubenimex can efficiently induce apoptosis of HL60 and K562 cells, this may be one of the mechanisms for inhibiting effect of Ubenimex on leukemia.