The Role of Mitochondrial VDAC2 in the Survival and Proliferation of T-Cell Acute Lymphoblastic Leukemia Cells

Background: T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with aberrant T-cell developmental arrest. Individuals with relapsed T-ALL have limited therapeutic alternatives and poor prognosis. The mitochondrial function is critical for the T-cell viability. The voltage-dependent anion channel 2 (VDAC2) in the mitochondrial outer membrane, interacts with pro-apoptotic BCL-2 proteins and mediates the apoptosis of several cancer cell lines. Objective: The aim of the current study is to explore the role of VDAC2 in T-ALL cell survival and proliferation. Methods: Publicly available datasets of RNA-seq results were analyzed for expression of VDAC isoforms and T-ALL cell lines were treated with a VDAC2 small molecular inhibitor erastin. A VDAC2 RNA interference (siRNA) was delivered to T-ALL cell lines using a retroviral vector. Functional assays were performed to investigate the VDAC2 siRNA impacts on cell proliferation, apoptosis and survival of T-ALL cells. Results: Our analysis found a high expression of VDAC2 mRNA in various T-ALL cell lines. Public datasets of T-ALL RNA-seq also showed that VDAC2 is highly expressed in T-ALL (116.2 ± 36.7), compared to control groups. Only two T-ALL cell lines showed sensitivity to erastin (20 μM) after 48 hours of incubation, including Jurkat (IC50 = 3.943 μM) and Molt4 (IC50 = 3.286 μM), while another two T-ALL cells (CUTLL1 and RPMI 8402) had unstable IC50. However, five T-ALL cell lines (LOUCY, CCRF-CEM, P12-ICHI, HPB-ALL, and PEER cells) showed resistance to erastin. On the contrary, all T-ALL cell lines genetically inhibited with VDAC2 siRNA led to more than 80% decrease in VDAC2 mRNA levels, and a Conclusion: VDAC2 is highly expressed in T-ALL cells. The inhibition of VDAC2 significantly decreased cell viability, increased apoptosis, reduced cell proliferation and caused cell cycle sub-G1 arrest of T-ALL cells.

Resveratrol Induces Apoptosis and Autophagy in T-cell Acute Lymphoblastic Leukemia Cells by Inhibiting Akt/mTOR and Activating p38-MAPK

Objective To explore the effects of resveratrol-induced apoptosis and autophagy in T-cell acute lymphoblastic leukemia （T-ALL） cells and potential molecular mechanisms. Methods The anti-proliferation effect of resveratrol-induced, apoptosis and autophagy on T-ALL cells were detected by using MTI- test, immunofluorescence, electronic microscope, and flow cytometry, respectively. Western blotting was performed for detecting changes of apoptosis-associated proteins, cell cycle regulatory proteins and state of activation of Akt, mTOR, p70S6K, 4E-BP1, and p38-MAPK. Results Resveratrol inhibited the proliferation and dose and time-dependent manner. It also induced cyclin-dependent kinase （CDK） inhibitors p21 and induced apoptosis and autophagy in T-ALL cells in a cell cycle arrest at G0/G1 phase via up regulating p27 and down regulating cyclin A and cyclin D1. Western blotting revealed that resveratrol significantly decreased the expression of antiapoptotic proteins （Mcl-1 and Bcl-2） and increased the expression of proapoptotic proteins （Bax, Bim, and Bad）, and induced cleaved-caspase-3 in a time-dependent manner. Significant increase in ratio of LC3-11/LC3-1 and Beclin 1 was also detected. Furthermore, resveratrol induced significant dephosphorylation of Akt, mTOR, p70S6K, and 4E-BP1, but enhanced specific phosphorylation of p38-MAPK which could be blocked by SB203580. When autophagy was suppressed by 3-MA, apoptosis in T-ALL cells induced by resveratrol was enhanced. Conclusion Our findings have suggested that resveratrol induces cell cycle arrest, apoptosis, and autophagy in T-ALL cells through inhibiting Akt/mTOR/p7OS6K/4E-BP1 and activating p38-MAPK signaling pathways. Autophagy might play a role as a self-defense mechanism in T-ALL cells treated by resveratrol. Therefore, the reasonable inhibition of autophagy in T-ALL cells may serve as a promising strategy for resveratrol induced apoptosis and can be used as adjuvant chemotherapy for T-ALL.

Predictive Value of Dynamic Peri-Transplantation MRD Assessed By MFC Either Alone or in Combination with Other Variables for Outcomes of Patients with T-Cell Acute Lymphoblastic Leukemia

We performed a retrospective analysis to investigate dynamic peri-hematopoieticstem cell transplantation(HSCT)minimal/measurable residual disease(MRD)on outcomes inpatients with T-cell acute lymphoblastic leukemia(T-ALL).A total of 271 patients were enrolledand classified into three groups:unchanged ncgative MRD pre-and post-HSCT group(group A),post-MRD non-increase group(group B),and post-MRD increase group(group C).The patientsin group B and group C experienced a higher cumulative incidence of relapse(CIR)(42%vs.71%vs.16%,P<0.001)and lower leukemia-free survival(LFS)(46%vs.21%vs.70%,P<0.001)andoverall survival(OS)(50%vs.28%vs.72%,P<0.001)than in group A,but there was no significantdifference in non-relapse mortality(NRM)among three groups(14%vs.12%vs.8%,P=0.752).Multivariate analysis showed that dynamic peri-HSCT MRD was associated with CIR(HR=2.392,95%CI,1.816-3.151,P<0.001),LFS(HR=1.964,95%CI,1.546-2.496,P<0.001)and os(HR=1.731,95%CI,1.348-2.222,P<0.001).We also established a risk scoring system based ondynamic peri-HSCT MRD combined with remission status pre-HSCT and onsct of chronic graft-versus-host disease(GVHD).This risk scoring system could better distinguish ClR(c=0.730)thanthat for pre-HSCT MRD(c=0.562),post-HSCT MRD(c=0.616)and pre-and post-MRD dynamics(c=0.648).Our results confirm the outcome predictive value of dynamic peri-HSCT MRD eitheralone or in combination with other variables for patients with T-ALL.

MicroRNA-145-3p suppresses the malignant behaviors of T-cell acute lymphoblastic leukemia Jurkat cells via inhibiting the NF-kappaB signaling pathway

T-cell acute lymphoblastic leukemia(T-ALL)is a hematological tumor caused by the malignant transformation of immature T-cell progenitor cells.Emerging studies have stated that microRNAs(miRNAs)may play key roles in T-ALL progression.This study aimed to investigate the roles of miR-145-3p in T-ALL cell proliferation,invasion,and apoptosis with the involvement of the nuclear factor-kappaB(NF-κB)signaling pathway.T-ALL Jurkat cells were harvested,and the expression of miR-145-3p and NF-κB-p65 was measured.Gain-and loss-of-functions of miR-145-3p and NF-κB-p65 were performed to identify their roles in the biological behaviors of Jurkat cells,including proliferation,apoptosis,and invasion.Consequently,the current study demonstrated that miR-145-3p was down-regulated while NF-κB-p65 was up-regulated in Jurkat cells.miR-145-3p directly bound to the 3’untranslated region of NF-κB-p65.Over-expression of miR-145-3p inhibited Jurkat cell proliferation,invasion,and resistance to apoptosis,while over-expression of NF-κB-p65 presented opposite trends.Co-transfection of miR-145-3p and NF-κB-p65 promoted the malignant behaviors of Jurkat cells compared to miR-145-3p transfection alone,while it reduced these behaviors of Jurkat cells compared to NF-κB-p65 transfection alone.Taken together,this study provided evidence that miR-145-3p could suppress proliferation,invasion,and resistance to the death of T-ALL cells via inactivating the NF-κB signaling pathway.

Multi-omics integration reveals potential stage-specific druggable targets in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia(T-ALL),a heterogeneous hematological malignancy,is caused by the developmental arrest of normal T-cell progenitors.The development of targeted therapeutic regimens is impeded by poor knowledge of the stage-specific aberrances in this disease.In this study,we performed multi-omics integration analysis,which included mRNA expression,chromatin accessibility,and gene-dependency database analyses,to identify potential stage-specific druggable targets and repositioned drugs for this disease.This multi-omics integration helped identify 29 potential pathological genes for T-ALL.These genes exhibited tissue-specific expression profiles and were enriched in the cell cycle,hematopoietic stem cell differentiation,and the AMPK signaling pathway.Of these,four known druggable targets(CDK6,TUBA1A,TUBB,and TYMS)showed dysregulated and stage-specific expression in malignant T cells and may serve as stage-specific targets in T-ALL.The TUBA1A expression level was higher in the early T cell precursor(ETP)-ALL cells,while TUBB and TYMS were mainly highly expressed in malignant T cells arrested at the CD4 and CD8 double-positive or single-positive stage.CDK6 exhibited a U-shaped expression pattern in malignant T cells along the naıve to maturation stages.Furthermore,mebendazole and gemcitabine,which target TUBA1A and TYMS,respectively,exerted stage-specific inhibitory effects on T-ALL cell lines,indicating their potential stage-specific antileukemic role in T-ALL.Collectively,our findings might aid in identifying potential stage-specific druggable targets and are promising for achieving more precise therapeutic strategies for T-ALL.

Current assessment and management of measurable residual disease in patients with acute lymphoblastic leukemia in the setting of CAR-T-cell therapy

Chimeric antigen receptor(CAR)-modified T-cell therapy has achieved remarkable success in the treatment of acute lymphoblastic leukemia(ALL).Measurable/minimal residual disease(MRD)monitoring plays a significant role in the prognostication and management of patients undergoing CAR-T-cell therapy.Common MRD detection methods include flow cytometry(FCM),polymerase chain reaction(PCR),and next-generation sequencing(NGS),and each method has advantages and limitations.It has been well documented that MRD positivity predicts a poor prognosis and even disease relapse.Thus,how to perform prognostic evaluations,stratify risk based on MRD status,and apply MRD monitoring to guide individual therapeutic decisions have important implications in clinical practice.This review assesses the common and novel MRD assessment methods.In addition,we emphasize the critical role of MRD as a prognostic biomarker and summarize the latest studies regarding MRD-directed combination therapy with CAR-T-cell therapy and allogeneic hematopoietic stem cell transplantation(allo-HSCT),as well as other therapeutic strategies to improve treatment effect.Furthermore,this review discusses current challenges and strategies for MRD detection in the setting of disease relapse after targeted therapy.

Advances in the development of chimeric antigen receptor-T-cell therapy in B-cell acute lymphoblastic leukemia

CD19-targeted chimeric antigen receptor T-cell(CAR-T)therapy is effective in refractory/relapsed(R/R)B-cell acute lymphoblastic leukemia(B-ALL).This review focuses on achievements,current obstacles,and future directions in CAR-T research.A high complete remission rate of 68%to 93%could be achieved after anti-CD19 CAR-T treatment for B-ALL.Cytokine release syndrome and CAR-T-related neurotoxicity could be managed.In view of difficulties collecting autologous lymphocytes,universal CAR-T is a direction to explore.Regarding the high relapse rate after anti-CD19 CAR-T therapy,the main solutions have been developing new targets including CD22 CAR-T,or CD19/CD22 dual CAR-T.Additionally,some studies showed that bridging into transplant post-CAR-T could improve leukemia-free survival.Some patients who did not respond to CAR-T therapy were found to have an abnormal conformation of the CD19 exon or trogocytosis.Anti-CD19 CAR-T therapy for R/R B-ALL is effective.From individual to universal CAR-T,from one target to multi-targets,CAR-T-cell has a chance to be off the shelf in the future.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia(T-ALL)is one of the most dangerous hematological malignancies,with high tumor heterogeneity and poor prognosis.More than 60%of T-ALL patients carry NOTCH1 gene mutations,leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways.We found that chidamide,an HDAC inhibitor,exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity.In particular,chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1(NICD1)as well as MYC,partly through their ubiquitination and degradation by the proteasome pathway.We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease(MRD)in patients and is well tolerated.Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients,including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

Haploidentical hematopoietic stem cell transplantation may improve long-term survival for children with high-risk T-cell acute lymphoblastic leukemia in first complete remission

Background: The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with high-risk (HR) T-cell acute lymphoblastic leukemia (T-ALL) in first complete remission (CR1) is still under evaluation. Moreover, relapse is the main factor affecting survival. This study aimed to explore the effect of allo-HSCT (especially haploidentical HSCT [haplo-HSCT]) on improving survival and reducing relapse for HR childhood T-ALL in CR1 and the prognostic factors of childhood T-ALL in order to identify who could benefit from HSCT.Methods: A total of 74 newly diagnosed pediatric T-ALL patients between January 1, 2012 and June 30, 2018 were enrolled in this retrospective study. Patients were stratified into the low-risk chemotherapy cohort (n = 16), HR chemotherapy cohort (n = 31), and HR transplant cohort (n = 27). Characteristics, survival outcomes, and prognostic factors of all patients were then analyzed.Results: Patient prognosis in the HR chemotherapy cohort was significantly worse than that in the low-risk chemotherapy cohort (5-year overall survival [OS]: 58.5%vs. 100%,P = 0.003;5-year event-free survival [EFS]: 54.1%vs. 83.4%,P = 0.010;5-year cumulative incidence of relapse [CIR]: 45.2%vs. 6.3%,P = 0.011). In HR patients, allo-HSCT improved the 5-year EFS and CIR compared to that of chemotherapy (5-year EFS: 80.1%vs. 54.1%,P = 0.041;5-year CIR: 11.6%vs. 45.2%,P = 0.006). The 5-year OS was higher in the HR transplant cohort than that in the HR chemotherapy cohort (81.0%vs. 58.5%,P = 0.084). Minimal residual disease re-emergence was an independent risk factor for 5-year OS, EFS, and CIR;age ≥10 years was an independent risk factor for OS and EFS;and high white blood cell count was an independent risk factor for EFS and CIR.Conclusion: Allo-HSCT, especially haplo-HSCT, could effectively reduce relapse of children with HR T-ALL in CR1.

Animal models of T-cell acute lymphoblastic leukemia: mimicking the human disease

T-cell acute lymphoblastic leukemia(T-ALL)is a heterogeneous group of hematological tumors composed of distinct subtypes that vary in their genetic abnormalities.In the past decade,large-scale genomic analysis has shed new light on providing potentially important oncogenic or tumor suppressive candidates involved in the disease progression.Following in silico analysis,functional studies are usually performed to vigorously investigate the biological roles of candidate genes.For this purpose,animal models faithfully recapitulating the human disease are widely applied to decipher the mechanism underlying T-cell transformation.Conversely,an increased understanding of T-ALL biology,including identification of oncogene NOTCH1,TAL1 and MYC as well as tumor suppressor phosphatase and tensin homolog(PTEN),has significantly improved the development of T-ALL animal models.These progresses have opened opportunities for development of new therapeutic strategy to benefit T-ALL patients.In this review,we particularly summarize the mouse and zebrafish models used in T-ALL research and also the most recent advances from these in vivo studies.

Precision medicine in acute lymphoblastic leukemia

The cure rate of childhood acute lymphoblastic leukemia(ALL)has exceeded 90%in some contemporary clinical trials.However,the dose intensity of conventional chemotherapy has been pushed to its limit.Further improvement in outcome will need to rely more heavily on molecular therapeutic as well as immuno-and cellular-therapy approaches together with precise risk stratification.Children with ETV6-RUNX1 or hyperdiploid>50 ALL who achieve negative minimal residual disease during early remission induction are suitable candidates for reduction in treatment.Patients with Philadelphia chromosome(Ph)-positive or Ph-like ALL with ABL-class fusion should be treated with dasatinib.BH3 profiling and other preclinical methods have identified several high-risk subtypes,such as hypodiplod,early T-cell precursor,immature T-cell,KMT2A-rearranged,Ph-positive and TCF-HLF-positive ALL,that may respond to BCL-2 inhibitor venetoclax.There are other fusions or mutations that may serve as putative targets,but effective targeted therapy has yet to be established.For other high-risk patients or poor early treatment responders who do not have targetable genetic lesions,current approaches that offer hope include blinatumomab,inotuzumab and CAR-T cell therapy for B-ALL,and daratumumab and nelarabine for T-ALL.With the expanding therapeutic armamentarium,we should start focus on rational combinations of targeted therapy with non-overlapping toxicities.

Is there a role for B lymphocyte chimerism in the monitoring of B-acute lymphoblastic leukemia patients receiving allogeneic stem cell transplantation?

Objective: To determine the sensitivity and significance of B-cell chimerism for the detection of early engraftment, transplant rejection, and disease relapse. Methods: The dynamic monitoring of lineage-specific cell subtypes (B, T, and NK cells) was made in 20 B-cell acute lympho-blastic leukemia (B-ALL) patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the early period after allo-HSCT, the latest establishment of B-cell complete chimerism (CC) was observed in a majority of patients. Results: The percentage of donor cells of B-cell lineage was lower than the percent of T-cell lineage in most of the mixed chimerism (MC) patients. During graft rejection, the frequency of patients with decreasing MC of B-, T-and NK-cell lineage were 5/5, 2/5, and 2/5. When disease relapsed, five patients showed a faster decrease of the donor percent of B-cells than of T-or NK-cells. Only one patient displayed a more rapid decrease in NK-cells than in T-or B-cells. Conclusion: Monitoring of B-cell chimerism after HSCT seems to be valuable for insuring complete engraftment, anticipating graft rejection, and relapse in B-ALL patients. Copyright ? 2015, Chinese Medical Association Production. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Breathing adapted radiation therapy for leukemia relapse in the breast: A case report

BACKGROUND Infiltration of the breast by leukemic cells is uncommon but may manifest as an oncological emergency requiring prompt management.Extramedullary relapse of T-cell acute lymphoblastic leukemia(T-ALL)within the breast is exceedingly rare and there is paucity of data in the literature regarding this entity.No consensus exists on management of isolated extramedullary breast relapses of T-ALL.Herein,we report a case of isolated extramedullary breast relapse of T-ALL treated with breathing adapted radiation therapy(BART)using the active breathing control(ABC)system.CASE SUMMARY The patient was a 33-year-old female with diagnosis of T-ALL.She received intensive systemic chemotherapy that resulted in complete remission of her disease,and then underwent allogeneic hematopoietic stem cell transplantation.After a 15 mo period without symptoms and signs of progression,the patient presented with palpable masses in both breasts.She complained from severe pain and swelling of the breasts.Imaging workup showed bilateral breast lesions,and diagnosis of breast infiltration by leukemic cells was confirmed after immunohistopathological evaluation.The patient suffering from severe pain,discomfort,and swelling of both breasts due to leukemic infiltration was referred to the Radiation Oncology Department for symptomatic palliation.Whole breast irradiation was delivered to both breasts of the patient with BART using the ABC system.The patient had complete resolution of her symptoms after treatment with BART.CONCLUSION BART with the ABC system resulted in complete resolution of the patient’s symptoms due to leukemic infiltration of both breasts with T-ALL.This contemporary treatment technique should be preferred for radiotherapeutic management of patients with leukemic infiltration of the breasts to achieve effective symptomatic palliation.

LIM domain only 1:an oncogenic transcription cofactor contributing to the tumorigenesis of multiple cancer types

The LIM domain only 1(LMO1)gene belongs to the LMO family of genes that encodes a group of transcriptional cofactors.This group of transcriptional cofactors regulates gene transcription by acting as a key"connector"or"scaffold"in transcription complexes.All LMOs,including LMO1,are important players in the process of tumorigenesis.Unique biological features of LMO1 distinct from other LMO members,such as its tissue-specific expression patterns,interacting proteins,and transcriptional targets,have been increasingly recognized.Studies indicated that LMO1 plays a critical oncogenic role in various types of cancers,including T-cell acute lymphoblastic leukemia,neuroblastoma,gastric cancer,lung cancer,and prostate cancer.The molecular mechanisms underlying such functions of LMO1 have also been investigated,but they are currently far from being fully elucidated.Here,we focus on reviewing the current findings on the role of LMO1 in tumorigenesis,the mechanisms of its oncogenic action,and the mechanisms that drive its aberrant activation in cancers.We also briefly review its roles in the development process and non-cancer diseases.Finally,we discuss the remaining questions and future investigations required for promoting the translation of laboratory findings to clinical applications,including cancer diagnosis and treatment.