A national, multicenter, retrospective study of Castleman disease in China implementing CDCN criteria.

Background: Castleman disease (CD) is a group of rare and heterogenous lymphoproliferative disorders including unicentric CD (UCD), human herpesvirus-8(HHV-8)-associated multicentric CD (HHV8-MCD), and HHV-8-negative/idiopathic multicentric CD (iMCD). Knowledge of CD mainly comes from case series or retrospective studies, but the inclusion criteria of these studies vary because the Castleman Disease Collaborative Network (CDCN) diagnostic criteria for iMCD and UCD were not available until 2017 and 2020, respectively. Further, these criteria and guidelines have not been systematically evaluated. Methods: In this national, multicenter, retrospective study implementing CDCN criteria, we enrolled 1634 CD patients (UCD, n = 903; MCD, n = 731) from 2000 to 2021 at 40 Chinese institutions to depict clinical features, treatment options, and prognostic factors of CD. Findings: Among UCD, there were 162 (17.9%) patients with an MCD-like inflammatory state. Among MCD, there were 12 HHV8-MCD patients and 719 HHV-8-negative MCD patients, which included 139 asymptomatic MCD (aMCD) and 580 iMCD meeting clinical criteria. Of 580 iMCD patients, 41 (7.1%) met iMCD-TAFRO criteria, the others were iMCD-NOS. iMCD-NOS were further divided into iMCD-IPL (n = 97) and iMCD-NOS without IPL (n = 442). Among iMCD patients with first-line treatment data, a trend from pulse combination chemotherapy toward continuous treatment was observed. Survival analysis revealed significant differences between subtypes and severe iMCD (HR = 3.747; 95% CI: 2.112-6.649, p < 0.001) had worse outcome. Interpretation: This study depicts a broad picture of CD, treatment options and survival information in China and validates the association between the CDCN's definition of severe iMCD and worse outcomes, requiring more intensive treatment. Fundings: Beijing Municipal Commission of Science and Technology, CAMS Innovation Fund and National High Level Hospital Clinical Research Funding.

Chidamide and sintilimab combination in diffuse large B-cell lymphoma progressing after chimeric antigen receptor T therapy.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is curable with first-line chemoimmunotherapy but patients with relapsed/refractory (R/R) DLBCL still face a poor prognosis. For patients with R/R DLBCL, the complete response rate to traditional next-line therapy is only 7% and the median overall survival is 6.3 mo. Recently, CD19-targeting chimeric antigen receptor T cells (CAR-T) have shown promise in clinical trials. However, approximately 50% of patients treated with CAR-T cells ultimately progress and few salvage therapies are effective. CASE SUMMARY: Here, we report on 7 patients with R/R DLBCL whose disease progressed after CAR-T infusion. They received a PD-1 inhibitor (sintilimab) and a histone deacetylase inhibitor (chidamide). Five of the 7 patients tolerated the treatment without any serious adverse events. Two patients discontinued the treatment due to lung infection and rash. At the 20-mo follow-up, the median overall survival of these 7 patients was 6 mo. Of note, there were 2 complete response rates (CRs) and 2 partial response rates (PRs) during this novel therapy, with an overall response rate (ORR) of 57.1%, and one patient had a durable CR that lasted at least 20 mo. CONCLUSION: In conclusion, chidamide combined with sintilimab may be a choice for DLBCL patients progressing after CD19-targeting CAR-T therapy.

CAG regimen for refractory or relapsed adult T-cell acute lymphoblastic leukemia: A retrospective, multicenter, cohort study.

Adult patients with relapsed or refractory T-cell acute lymphoblastic leukemia (R/R-T-ALL) have extremely poor prognosis, representing an urgent unmet medical need. Finding an optimal salvage regimen to bridge transplantation is a priority. The CAG (cytarabine, aclarubicin, and G-CSF) regimen was initially used by one group in China, showing unexpectedly promising results in 11 R/R-T-ALL patients. Here, we report the multicenter results of 41 patients who received the CAG regimen as salvage therapy. After one cycle of the CAG regimen, complete remission and partial remission were achieved in 33 (80.5%) and two (4.9%) patients, respectively. Failure to respond was observed in six patients (14.6%). Early T-cell precursor (ETP) (n = 26) and non-ETP (n = 15) patients had a similar CR rate (80.8% vs 80.0%, P = .95). Among 41 patients, allo-HSCT was successfully performed in 27 (66%) patients (22 in CR and 5 in non-CR). With a median follow-up time of 12 months, the estimated 2-year overall survival and event-free survival were 68.8% (95% CI, 47.3%-83.0%) and 56.5% (95% CI, 37.1%-71.9%), respectively. The CAG regimen was well-tolerated, and no early death occurred. Our multicenter results show that the CAG regimen is highly effective and safe, representing a novel choice for adult patients with R/R-T-ALL and providing a better bridge to transplantation.

Genomic and Transcriptomic Characterization of Natural Killer T Cell Lymphoma.

Natural killer/T cell lymphoma (NKTCL) is an aggressive and heterogeneous entity of non-Hodgkin lymphoma, strongly associated with Epstein-Barr virus (EBV) infection. To identify molecular subtypes of NKTCL based on genomic structural alterations and EBV sequences, we performed multi-omics study on 128 biopsy samples of newly diagnosed NKTCL and defined three prominent subtypes, which differ significantly in cell of origin, EBV gene expression, transcriptional signatures, and responses to asparaginase-based regimens and targeted therapy. Our findings thus identify molecular networks of EBV-associated pathogenesis and suggest potential clinical strategies on NKTCL.

MNK1 inhibitor CGP57380 overcomes mTOR inhibitor-induced activation of eIF4E: the mechanism of synergic killing of human T-ALL cells.

Although the treatment of adult T-cell acute lymphoblastic leukemia (T-ALL) has been significantly improved, the heterogeneous genetic landscape of the disease often causes relapse. Aberrant activation of mammalian target of rapamycin (mTOR) pathway in T-ALL is responsible for treatment failure and relapse, suggesting that mTOR inhibition may represents a new therapeutic strategy. In this study, we investigated whether the mTOR complex 1 (mTORC1) inhibitor everolimus could be used as a therapeutic agent against human T-ALL. We showed that rapamycin and its analog RAD001 (everolimus) exerted only mild inhibition on the viability of Jurkat, CEM and Molt-4 cell lines (for everolimus the maximum inhibition was <40% at 100 nM), but greatly enhanced the phosphorylation of eIF4E, a downstream substrate of MAPK-interacting kinase (MNK) that was involved in promoting cell survival. Furthermore, we demonstrated in Jurkat cells that mTOR inhibitor-induced eIF4E phosphorylation was independent of insulin-like growth factor-1/insulin-like growth factor-1 receptor axis, but was secondary to mTOR inhibition. Then we examined the antileukemia effects of CGP57380, a MNK1 inhibitor, and we found that CGP57380 (4-16 µM) dose-dependently suppressed the expression of both phosphor-MNK1 and phosphor-eIF4E, thereby inhibiting downstream targets such as c-Myc and survivin in T-ALL cells. Importantly, CGP57380 produced a synergistic growth inhibitory effect with everolimus in T-ALL cells, and treatment with this targeted therapy overcame everolimus-induced eIF4E phosphorylation. In conclusion, our results suggest that dual-targeting of mTOR and MNK1/eIF4E signaling pathways may represent a novel therapeutic strategy for the treatment of human T-ALL.

Combing oncolytic adenovirus expressing Beclin-1 with chemotherapy agent doxorubicin synergistically enhances cytotoxicity in human CML cells in vitro.

Cancer virotherapy provides a new strategy to treat cancer that can directly kill cancer cells by oncolysis. Insertion of therapeutic genes into the genome of a modified adenovirus, thereby creating a so-called gene-virotherapy that shares the advantages of gene therapy and virotherapy. In this study we investigated whether a strategy that combines the oncolytic effects of an adenoviral vector with the simultaneous expression of the autophagy gene Beclin-1 offered a therapeutic advantage for chronic myeloid leukemia (CML) cells with resistance to chemotherapy and evaluated the synergistic effects of SG511-BECN and doxorubicin (Dox) in human CML cells in vitro. Oncolytic virus SG511-BECN was constructed through introducing the Beclin-1 gene into the oncolytic adenoviral backbone. SG511-BECN displayed significantly improved antileukemia activity on multidrug-resistant CML cell line K562/A02, which was mediated via induction of autophagic cell death. Furthermore, Dox could synergize with SG511-BECN to kill the CML cells by improving the infectious efficiency of the oncolytic adenovirus without causing significant damage to normal human mononuclear cells. The results demonstrate that targeting the autophagic cell death pathway and combination of a chemotherapy agent with oncolytic adenovirus may be a novel strategy for the treatment of leukemia with chemotherapy resistance.

[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.

Pure total flavonoids from Citrus paradisi Macfadyen act synergistically with arsenic trioxide in inducing apoptosis of Kasumi-1 leukemia cells in vitro.

To investigate the potential effects of pure total flavonoid compounds (PTFCs) from Citrus paradisi Macfadyen separately or combined with arsenic trioxide on the proliferation of human myeloid leukemia cells and the mechanisms underlying the action of PTFCs. The effects of PTFCs separately or combined with arsenic trioxide on the proliferation and apoptosis of leukemia cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), fluorescence microscopy, and flow cytometry. Their effects on the expression levels of apoptosis-related regulators were determined by Western blot assay. PTFCs combined with arsenic trioxide significantly inhibited the growth of Kasumi-1 cells, and apoptosis was confirmed by flow cytometry analysis. Hoechst 33258 staining showed more significant morphological changes and more apoptosis following the combined treatment. Western blots showed changes in the expression of genes for poly ADP-ribose polymerase (PARP), caspase 3/9, and P65. The results indicated that PTFCs separately or combined with arsenic trioxide inhibited proliferation of leukemia cells in vitro and induced their apoptosis by modulating the expression of apoptosis-related regulator genes.

[Apoptosis of acute myeloid leukemia HL-60 cells induced by CDK inhibitor SNS-032 and its molecular mechanisms].

OBJECTIVE: To investigate the effects of cycle-dependent kinase (CDK) inhibitor SNS-032 on apoptosis in human acute myeloid leukemia (AML) HL-60 cells and its molecular mechanisms. METHODS: Cultured AML HL-60 cells were treated with various concentrations of SNS-032. Cell apoptosis was determined with flow cytometry;cell viability was measured by MTT assay; the profiles of microRNA expression of HL-60 cells were analyzed by microRNA microarray;the protein expressions of JAK2/STAT3 pathway were detected by Western blotting. RESULTS: Apoptosis of AML HL-60 cells was induced by SNS-032; the rate of apoptosis was (5.9±1.7)%, (12.1±3.1)% and (59.4±3.6)% when HL-60 cells were treated with 0,100 and 200 nmol/L SNS-032. MicroRNA microarray analysis revealed that the levels of miR-30a, miR-183, miR-20b, miR-26b, miR-20a, miR-589, miR-107, miR-181a, miR-106a, miR-17 and miR-378c were down-regulated by SNS-032,whereas the levels of miR-320a and miR-H7* were up-regulated. Western blotting showed that SNS-032 strongly inhibited phosphorylation of STAT3 and protein expression of JAK2,C-MYC and MCL-1. CONCLUSION: CDK inhibitor SNS-032 can induce apoptosis of AML HL-60 cells, which is associated with the inhibition of MCL-1,C-MYC and JAK2/STAT3, and down-regulation of miR-17-92 family.

[Imatinib mesylate for chronic myeloid leukemia: in patients with initial treatment versus those with Recombinant Human IFN-α2b treatment failure].

OBJECTIVE: To evaluate the efficacy of imatinib mesylate (IM) for patients with newly diagnosed chronic myeloid leukemia (CML) and patients after failure of Recombinant Human interferon-α2b (IFN-α2b) therapy. METHODS: A total of 86 patients with CML in chronic-phase, including 61 newly diagnosed cases and 25 cases of IFN-α2b failure, who received IM at 400 mg daily were retrospectively analyzed. Conventional cytogenetic analysis of R-banding was used to detect chromosome abnormalities and real-time PCR was used to detect BCR-ABL fusion gene. RESULTS: 81.9% of newly diagnosed patients and 36.0% of IFN-α2b failure patients achieved partial cytogenetic response (PCyR) by 6 months. In addition, 86.9% of newly diagnosed patients and 68.0% of IFN-α2b failure patients achieved complete cytogenetic response (CCyR) in 24 months. There was significant difference between two groups (P<0.001). The median time achieved CCyR in newly diagnosed group and IFN-α2b failure group were 6 months and 15 months, respectively. Compared with newly diagnosed group, IFN-α2b failure group showed lower rate of complete molecular remission (CMR) (70.4% vs 40.0%, P=0.033). There are 14 patients (22.9%) in newly diagnosed patients with cytogenetic resistance, among whom 4 with primary cytogenetic resistance; while there were 14 patients (56.0%) in IFN-α2b failure group with cytogenetic resistance, all of whom with primary resistance. CONCLUSION: Compared with newly diagnosed patients, CML patients after failure of IFN-α2b therapy have a high rate of primary cytogenetic resistance and low response rate to IM.

Matrine and CYC116 synergistically inhibit growth and induce apoptosis in multiple myeloma cells.

OBJECTIVE: To investigate whether CYC116 can potentiate matrine-dependent growth inhibition and apoptosis in multiple myeloma (MM) cells. METHODS: The dose response relationship of matrine to dexamethasone-resistant and dexamethasone-sensitive MM cells was first established. Myeloma RPMI8226 cells were treated with matrine alone or combined with CYC116 for 24 h. Cell proliferation was measured using an MTT assay and apoptosis induction was evaluated by flow cytometry. Activation of the caspase pathway and expression of apoptosis regulator proteins were detected by Western blotting. RESULTS: Matrine significantly induced growth arrest and apoptosis in both drug-resistant and drug-sensitive MM cells. Treatment with the combination of matrine and CYC116 had a stronger cytotoxic effect on MM cells than did single drug treatments. Enhanced apoptosis observed following the combined treatment of matrine and CYC116 was associated with higher levels of activation of caspase-9, caspase-3, and poly adenosine diphosphate ribose polymerase (PARP) and down-regulation of the anti-apoptotic proteins Bcl-2 and Mcl-1 and the signaling proteins p-Akt and nuclear factor κB (NF-κB). CONCLUSION: CYC116 enhances the growth inhibitory and apoptotic effects of matrine on MM cells.

Spontaneous spinal epidural haematoma.

Spontaneous spinal epidural haematoma (SSEH) is a rare clinical condition with unknown aetiology. Prompt diagnosis and treatment are paramount because of the risk of permanent neurological deficits without appropriate intervention. We described a case of a 48-year-old man presenting with complete quadriplegia and hypoesthesia. Magnetic resonance imaging revealed cervical cord compression due to a haematoma posterior to the spinal cord. Surgical decompression and evacuation of the haematoma was performed within 12 hours after admission to the authors' hospital. Both the patient's motor and sensory functions recovered soon after the operation. Early surgical decompression for SSEH with neurologic impairment is therefore recommended for the recovery of this patient and also serves as a relevant reference for orthopaedic clinics. Foundation number: CXZZ20140414170821148.

[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.

[Homoharringtonine combined arsenic trioxide induced apoptosis in human multiple myeloma cell line RPMI 8226: an experimental research].

OBJECTIVE: To clarify the effects and mechanisms of homoharringtonine (HHT) monomer therapy or combination therapy with arsenic trioxide (ATO) on human multiple myeloma (MM) cell line RPMI 8226 in in vitro researches. METHODS: Effects of HHT, ATO, and HHT combined ATO on the growth of MM cell line RPMI 8226 were detected using MTT assay. The morphological changes of cell apoptosis were detected by Hoechst staining. The early apoptosis rate was detected using flow cytometry. Expressions of Caspase-3, Caspase-9, poly-ADP-ribose polymerase (PARP), Bcl-2, Mcl-1, Bcl-xl, and AKT protein were detected by Western blot. RESULTS: HHT and ATO inhibited the proliferation of RPM1 8226 cell line in a time- and dose-dependent manner (P < 0.05). Synergistic effects was shown in the combination group (Cl < 1). HHT and ATO induced the apoptosis of RPMI 8226 in a dose-dependent manner with typical morphological changes of apoptosis and higher early stage apoptosis rate. The enhancement in apoptotic induction was seen when two agents were combined. HHT activated expressions of Caspase-3 and PARP in a dose dependent manner at 24 h. HHT at 40 ng/mL and ATO at 8.5 micromol/L could significantly activate expressions of Caspase-3 and Caspase-9, and down-regulate expressions of anti-apoptotic proteins Bcl-xl and Mcl-1. In addition, the combination therapy of HHT at 40 ng/mL and ATO at 8.5 micromol/L inhibited phosphorylation of AKT in a time-dependent manner. CONCLUSION: HTT, ATO, and combination therapy of HHT and ATO induced the apoptosis of RPMI 8226 cell line possibly through activating Caspase pathways, regulating expressions of Bcl-2 families, and inhibiting phosphorylation of AKT.

[Synergistic effect of histone deacetylase inhibitor suberoylanilide hydroxamic acid with imatinib on K562 cells].

OBJECTIVE: To investigate synergistically killing effect of histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) combined with imatinib on human chronic myeloid leukemia (CML) cell line. METHODS: K562 cells were co-treated with SAHA and imatinib. Cell growth was measured by MTT assay. Apoptosis was determined using Hoechst staining apoptosis detection kit and flow cytometric analysis. Activation of Caspase pathway, expression of Bcr-Abl and its downstream target genes, and expression of anti-apoptotic proteins were detected by Western blot. RESULTS: SAHA synergized the cytotoxicity of imatinib against leukemia K562 cells, concomitantly with increased apoptosis and enhanced activation of Caspase-3, -8 and PRAP. The combination therapy resulted in significantly lower levels of Bcr-Abl,phosphorylated Bcr-Abl compared to treatment with either SAHA or imatinib alone. Furthermore,the co-treatment resulted in down-regulation of anti-apoptotic protein Mcl-1 expression. Also,marked down-regulated expression of JAK2,STAT5,and phosphorylated STAT5 was detected in the combination therapy. CONCLUSION: Combining HDAC inhibitor SAHA with imatinib can kill CML cells synergistically by inhibiting cell growth and inducing apoptosis, which is associated with activation of Caspase pathway and regulation of anti-apoptotic proteins.

[Killing effect of aurora kinase inhibitor ENMD-2076 on acute myelogenous leukemia cells].

OBJECTIVE: To investigate the effect of aurora kinase inhibitor ENMD-2076 on human acute myelogenous leukemia (AML) cell lines. METHODS: AML THP-1 and Kasumi-1 cells were treated with ENMD-2076 for 24 h and 48 h,respectively. Cell growth was measured by MTT assay. Apoptosis was determined using Hoechst staining apoptosis detection kit. Activation of Caspase pathway and expression of apoptosis regulator proteins were detected by Western blot. RESULTS: ENMD-2076 significantly induced growth arrest and apoptosis in THP-1 and Kasumi-1 cells. Enhanced apoptosis was observed in ENMD-2076 group evidenced by strong activation of Caspase-9,Caspase-3 and PARP. Furthermore,the ENMD-2076 treatment resulted in down-regulation of anti-apoptotic protein Mcl-1 expression. Also,up-regulated expression of pro-apoptotic protein Bak,Bad and Bax was detected after ENMD-2076 treatment. CONCLUSION: ENMD-2076 can kill effectively AML cells by inhibiting cell growth and inducing apoptosis,which is associated with activation of Caspase pathway and regulation of pro-apoptotic and anti-apoptotic proteins.

[Cytotoxicity of homoharringtonine on leukemic stem-like cells in AML cell line KG-1].

OBJECTIVE: To investigate the effect of homoharringtonine (HHT) on leukemic stem-like cells (LSC) in human acute myeloid leukemia (AML) cell lines. METHODS: The phenotypes of AML cell lines U937,Kasumi-1,and KG-1 cells were analyzed by flow cytometry (FACS). The effect of HHT on leukemia stem-like cells with immunophenotype of CD34(+)CD38(-)CD96(+) was detected with FACS. Cell growth was measured by MTT assay. Activation of Caspase pathway and expression of apoptosis-related regulator proteins were examined by Western blotting. RESULTS: FACS demonstrated that the 69% of KG-1 cells expressed LSC phenotype CD34(+)CD38(-)CD96(+), while 26.7% on Kasumi-1 cells expressed this marker. In contrast,U937 cells showed CD96 negative. HHT significantly inhibited cell growth of KG-1 cells with an IC(50) of 16.9 ng/ml at 48 h. The ratio of CD34(+)CD38(-)CD96(+) cells decreased from 63.6% to 17.1% after HHT treatment. Enhanced apoptosis was demonstrated in HHT group evidenced by strong activation of Caspase-9,Caspase-3 and PARP.HHT treatment resulted in down-regulation of expression of anti-apoptotic protein BCL-2 and phosphorylated-Akt. CONCLUSION: HHT can effectively kill the leukemic stem-like cells in human AML cell line KG1 by inhibiting cell growth and inducing apoptosis which is associated with activation of Caspase pathway and down-regulation of anti-apoptotic proteins and phosphorylated-Akt.

[Antitumor activity of histone deacetylase inhibitor suberic bishydroxamate on acute myeloid leukemia cell lines].

OBJECTIVE: To investigate the effect of histone deacetylase inhibitor suberic bishydroxamate (SBHA) on human acute myeloid leukemia (AML) cell lines. METHODS: AML U937, KG-1 and Kasumi-1 cells were treated with SBHA. Cell growth was measured by MTT assay. Apoptosis was determined using flow cytometry. Activation of Caspase pathway and expression of apoptosis regulator proteins were detected by Western blot. RESULTS: SBHA significantly induced growth arrest and apoptosis in U937, KG-1 and Kasumi-1 cells. Enhanced apoptosis was observed in SHBA group evidenced by strong activation of Caspase-9, Caspase-8 and Caspase-3. SHBA treatment resulted in down-regulation of anti-apoptotic protein Bcl-2 and Bcl-xl expression; down-regulated expression of antiapoptotic proteins survivin, XIAP and cIAP was also detected after SBHA treatment. CONCLUSION: SBHA can effectively kill AML cells by inhibiting cell growth and inducing apoptosis, which is associated with the activation of Caspase pathway and regulation of apoptotic related proteins.