Metformin is a commonly used drug for the treatment of diabetes. Accumulating evidence suggests that it exerts anti-tumor effects in many cancers, including multiple myeloma (MM); however, the ...underlying molecular mechanisms have not been clearly elucidated.
The anti-myeloma effects of metformin were evaluated using human MM cell lines (RPMI8226 and U266) in vitro and in vivo NOD-SCID murine xenograft MM model. Cell viability was assessed with CCK8 and cell proliferation was measured by EdU incorporation assay. Cell cycle distribution and apoptosis were examined by flow cytometry. Transmission electron microscopy was used to visualized autophagosomes. Activation of AMPK and inhibition of mTORC1/C2 pathways was assessed by Western blot analysis. RPMI8226 cells and U266 cell lines with AMPK knockdown were generated by transfection with small interfering RNA targeting the AMPK-α1 and α2 subunits using Lipofectamine 2000 reagent.
Metformin effectively inhibited the proliferation of MM cell lines, an effect that was associated with the induction of autophagy and G0/G1 cell cycle arrest, but not apoptosis. Metformin activated AMPK and repressed both mTORC1 and mTORC2 signaling pathways in myeloma cells as well as downstream molecular signaling pathways, such as p-4EBP1 and p-AKT. AMPK activation resulted in direct phosphorylation and activation of tuberous sclerosis complex 2 (TSC2), leading to inhibition of the mammalian target of rapamycin (mTOR). In addition, metformin inhibited myeloma cell growth in an AMPK-dependent manner. The xenograft mouse model further confirmed that metformin inhibited tumor growth by upregulation of AMPK and downregulation of mTOR.
Metformin inhibits the proliferation of myeloma cells by inducing autophagy and cell-cycle arrest. Our results suggest that the molecular mechanism involves dual repression of mTORC1 and mTORC2 pathways via AMPK activation. Our study provides a theoretical basis for the development of novel strategies for the treatment of MM using metformin as an already approved and safe drug.
Autologous stem-cell transplantation (ASCT) remains a beneficial approach for patients with newly diagnosed multiple myeloma (NDMM) in the age of novel therapeutic agents. Nevertheless, limited ...real-world data is available to establish criteria for identifying high-risk ASCT patients.
We analyzed outcomes for 168 NDMM patients who underwent ASCT at our center from December 2015 to December 2022. We investigated the impact of the number of high-risk cytogenetics (HRCA), defined as t(4;14), t(14;16), 1q21 gain/amplification, and del(17p), as well as the post-ASCT minimal residual disease (MRD) status as prognostic indicators. We assessed progression-free survival (PFS) and overall survival (OS), and focused on identifying risk factors.
The cohort included 42% of patients (n = 71) with 0 HRCA, 42% (n = 71) with 1 HRCA, and 16% (n = 26) with ≥ 2 HRCA. After a median follow-up of 31 months, the median PFS was 53 months (95% CI, 37-69), and OS was not reached for the entire cohort. Despite similar rates of MRD-negativity post-ASCT, patients with ≥ 2 HRCA, termed "double hit" (DH), had a significantly higher risk of progression/mortality than those with 0 or 1 HRCA. Multivariate analysis highlighted DH (HR 4.103, 95% CI, 2.046-8.231) and MRD positivity post-ASCT (HR 6.557, 95% CI, 3.217-13.366) as adverse prognostic factors for PFS, with DH also linked to inferior OS. As anticipated, DH patients with post-ASCT MRD positivity displayed the poorest prognosis, with a median PFS of 7 months post-ASCT. Meanwhile, DH patients with MRD negativity post-ASCT showed improved prognosis, akin to MRD-negative non-DH patients. It is noteworthy to exercise caution, as DH patients who initially achieved MRD negativity experienced a 41% cumulative loss of that status within one year.
This study strongly advocates integrating DH genetic assessments for eligible ASCT patients and emphasizes the importance of ongoing MRD monitoring, as well as considering MRD-based treatment adaptation for those patients in real-world settings.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Acute promyelocytic leukemia (APL) is a unique subtype of acute myeloid leukemia (AML). The prognosis of APL has changed from the worst among the AMLs to currently the best. The application of all- ...trans retinoic acid (ATRA) in the induction therapy of APL decreases the high mortality of newly diagnosed patients, thereby significantly improving the response rate. ATRA combined with anthracycline-based chemotherapy is the current standard treatment, and for high-risk patients, high doses cytarabine have a beneficial effect on relapse prevention. In recent years, the indications of arsenic trioxide (ATO) therapy for APL have been extended from the salvage therapy for relapse patients to the first-line treatment of de novo APL. The introduction of both ATRA and ATO represents great achievements in translational medicine. In this review article, we discuss the therapeutic strategies for this disease, including the initial approaches to newly diagnosed patients, prevention, and treatment of side effects and relapse to ensure the best and timely treatment for each newly diagnosed APL patient.
Glucocorticoids play a critical role in the treatment of lymphoid malignancies. While glucocorticoid efficacy can be largely attributed to lymphocyte-specific apoptosis, its molecular basis remains ...elusive. Here, we studied genome-wide lymphocyte-specific open chromatin domains (LSOs), and integrated LSOs with glucocorticoid-induced RNA transcription and chromatin modulation using an in vivo patient-derived xenograft model of acute lymphoblastic leukemia (ALL). This led to the identification of LSOs critical for glucocorticoid-induced apoptosis. Glucocorticoid receptor cooperated with CTCF at these LSOs to mediate DNA looping, which was inhibited by increased DNA methylation in glucocorticoid-resistant ALL and non-lymphoid cell types. Our study demonstrates that lymphocyte-specific epigenetic modifications pre-determine glucocorticoid resistance in ALL and may account for the lack of glucocorticoid sensitivity in other cell types.
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•Identified open chromatin domains associated with glucocorticoid response in ALL•Glucocorticoid-resistant ALL shows abnormal accessibility at GR-bound enhancers•GR and CTCF bind at a lymphocyte-specific enhancer for BIM to mediate DNA looping•The BIM enhancer is highly methylated in resistant ALL and non-lymphoid cell types
Jing et al. identified lymphocyte-specific open chromatin domains (LSOs) critical for glucocorticoid (GC)-induced acute lymphoblastic leukemia (ALL) apoptosis. GC receptor cooperated with CTCF at these LSOs to mediate DNA looping, which was inhibited by DNA methylation in GC-resistant ALL and non-lymphoid cell types.
DNMT3A R882H, a frequent mutation in acute myeloid leukemia (AML), plays a critical role in malignant hematopoiesis. Recent findings suggest that DNMT3A mutant acts as a founder mutation and requires ...additional genetic events to induce full-blown AML. Here, we investigated the cooperation of mutant DNMT3A and NRAS in leukemogenesis by generating a double knock-in (DKI) mouse model harboring both Dnmt3a R878H and Nras G12D mutations.
DKI mice with both Dnmt3a R878H and Nras G12D mutations were generated by crossing Dnmt3a R878H knock-in (KI) mice and Nras G12D KI mice. Routine blood test, flow cytometry analysis and morphological analysis were performed to determine disease phenotype. RNA-sequencing (RNA-seq), RT-PCR and Western blot were carried out to reveal the molecular mechanism.
The DKI mice developed a more aggressive AML with a significantly shortened lifespan and higher percentage of blast cells compared with KI mice expressing Dnmt3a or Nras mutation alone. RNA-seq analysis showed that Dnmt3a and Nras mutations collaboratively caused abnormal expression of a series of genes related to differentiation arrest and growth advantage. Myc transcription factor and its target genes related to proliferation and apoptosis were up-regulated, thus contributing to promote the process of leukemogenesis.
This study showed that cooperation of DNMT3A mutation and NRAS mutation could promote the onset of AML by synergistically disturbing the transcriptional profiling with Myc pathway involvement in DKI mice.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The past three decades have witnessed a great progress in the treatment of acute promyelocytic leukemia (APL). The current application of all-trans retinoic acid, arsenic trioxide (ATO), and ...anthracycline-based chemotherapies has been proved to be highly effective. Based on the risk factors of APL, optimization of the treatment emphasizes the role of ATO in induction, consolidation and maintenance therapy as a substitute to chemotherapy in low- and intermediate-risk patients, and in potential reduction of chemotherapy in high-risk group without impact on the outcome. However, early death and relapse remain obstacles to further improvement of the rates of remission and long-term survival, and the acute and chronic adverse effects of ATO should be considered for more appropriate management. Efforts should be made to more rationally obtain improved outcomes through the use of less toxic regimens.
BackgroundDespite recent advances in T-cell engager based multiple myeloma therapies, high rate of cytokine release syndrome (CRS) and severe neurotoxicity remains a challenge in clinic. EMB-06 is a ...novel 2+2 BCMA×CD3 T-Cell engaging bispecific antibody developed based on the EpimAb’s proprietary Fabs-In-Tandem-Immunoglobulin (FIT-Ig®) platform. Differentiated from existing T-cell engagers, EMB-06 comprises tetravalent binding domains in cis-configuration and proprietary anti-CD3 arms with optimized affinity. It induced modest levels of cytokine release yet retained robust anti-tumor activity in preclinical studies. Here we report the initial results from an ongoing multicenter, first-in-human, Phase I study of EMB-06 in relapsed or refractory multiple myeloma (RRMM).MethodsThe Phase I study evaluates escalating doses of once weekly IV administrations of EMB-06 in patients (pts) with RRMM who have failed or are intolerant to standard therapies. Dose escalation was guided by the Bayesian optimal interval (BOIN) design. Primary objectives were to assess safety, tolerability, and determine the MTD and/or RP2Ds. Secondary objectives were to assess pharmacokinetics (PK), pharmacodynamics (PD), immunogenicity, and preliminary anti-tumor activities.ResultsAs of Aug 28, 2023, 33 pts had been treated with EMB-06 at 0.2mg to 200mg. Median age was 66 y (46–82). Median prior lines of therapies were 3 (2–6) and 26 (79%) pts were refractory to the most recent line of therapy. Treatment-related AEs (TRAEs) were reported in 20 (61%) pts, with Gr ≥3 occurring in 7 (21%) pts. The most common TRAEs include ALT increase (18%), leukopenia (18%), ALP increase (15%), neutropenia (15%), anemia (12%), AST increase (12%), GGT increase (12%), lymphopenia (12%) and CRS (12%). All CRS were Grade 1. Only 1 patient experienced treatment related neurotoxicity (Gr.1 paresthesia). One DLT (pneumonia, cardiac failure, creatinine increased and hepatic insufficiency) was observed at 60mg cohort. EMB-06 shows dose proportional increase in PK exposure across 0.2–120 mg, and the median half-life after single dosing is 4.4 days. PD activity (T cell redistribution and activation along with transient release of low-level cytokines) was observed at doses ≥0.6mg. The ORR was 29% (9/31) among 31 response evaluable pts. Of the 5 evaluable pts treated with doses ≥120mg, the ORR was 100% (1 CR, 2 VGPR, 2 PR).ConclusionsEMB-06 demonstrated a differentiated safety profile in RRMM pts with exceptionally low CRS and neurotoxicity rates so far. An initial ORR of 100% has been observed at doses ≥120mg. Updated data will be shared at the meeting.Trial RegistrationThe clinical trial was registered with www.clinicaltrials.gov (NCT04735575).Ethics ApprovalThe trial was done according to Good Clinical Practice and the Declaration of Helsinki. The protocol and amendments were approved by the institutional review board or ethics committee at each site. And all participants gave informed consent before taking part in the trial. The name of the ethics committee(s) or institutional review board(s), the number/ID of the approval(s) are as follow:Epworth health – No. 2020-12-1350Sunshine Coast Haematology and Oncology Clinic- No. 2020-12-1350-AAOne Clinical Research - No. 2020-12-1350-AB Ethics Committee of Ruijin Hospital Affiliated to Shanghai Jiaotong University School Of Medicine-No. 2021- 73 Henan Cancer Hospital Medical Science Research Ethics Committee-No. 2021-381-002Clinical Trial Ethics Committee of Huazhong University of Science and Technology-No. 2021-218Ethics Committee of the First Affiliated Hospital, School Of Medicine, Zhejiang University-No. 2021-627 Ethics Committee of Beijing Jishuitan Hospital-No. 20210902-01Peking University Third Hospital Medical Science Research Ethics Committee-No.2022-220-02Ethics Committee of Guangdong Provincial People’s Hospital-No. YW2023-011-02ConsentWritten informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.
The outbreak of coronavirus disease 2019 (COVID-19) posed an unprecedented challenge on public health systems. Despite the measures put in place to contain it, COVID-19 is likely to continue ...experiencing sporadic outbreaks for some time, and individuals will remain susceptible to recurrent infections. Chimeric antigen receptor (CAR)-T recipients are characterized by durable B-cell aplasia, hypogammaglobulinemia and loss of T-cell diversity, which lead to an increased proportion of severe/critical cases and a high mortality rate after COVID-19 infection. Thus, treatment decisions have become much more complex and require greater caution when considering CAR T-cell immunotherapy. Hence, we reviewed the current understanding of COVID-19 and reported clinical experience in the management of COVID-19 and CAR-T therapy. After a panel discussion, we proposed a rational procedure pertaining to CAR-T recipients with the aim of maximizing the benefit of CAR-T therapy in the post COVID-19 pandemic era.
Background
Abnormal alternative splicing is frequently associated with carcinogenesis. In B‐cell acute lymphoblastic leukemia (B‐ALL), double homeobox 4 fused with immunoglobulin heavy chain ...(DUX4/IGH) can lead to the aberrant production of E‐26 transformation‐specific family related gene abnormal transcript (ERGalt) and other splicing variants. However, the molecular mechanism underpinning this process remains elusive. Here, we aimed to know how DUX4/IGH triggers abnormal splicing in leukemia.
Methods
The differential intron retention analysis was conducted to identify novel DUX4/IGH‐driven splicing in B‐ALL patients. X‐ray crystallography, small angle X‐ray scattering (SAXS), and analytical ultracentrifugation were used to investigate how DUX4/IGH recognize double DUX4 responsive element (DRE)‐DRE sites. The ERGalt biogenesis and B‐cell differentiation assays were performed to characterize the DUX4/IGH crosslinking activity. To check whether recombination‐activating gene 1/2 (RAG1/2) was required for DUX4/IGH‐driven splicing, the proximity ligation assay, co‐immunoprecipitation, mammalian two hybrid characterizations, in vitro RAG1/2 cleavage, and shRNA knock‐down assays were performed.
Results
We reported previously unrecognized intron retention events in C‐type lectin domain family 12, member A abnormal transcript (CLEC12Aalt) and chromosome 6 open reading frame 89 abnormal transcript (C6orf89alt), where also harbored repetitive DRE‐DRE sites. Supportively, X‐ray crystallography and SAXS characterization revealed that DUX4 homeobox domain (HD)1‐HD2 might dimerize into a dumbbell‐shape trans configuration to crosslink two adjacent DRE sites. Impaired DUX4/IGH‐mediated crosslinking abolishes ERGalt, CLEC12Aalt, and C6orf89alt biogenesis, resulting in marked alleviation of its inhibitory effect on B‐cell differentiation. Furthermore, we also observed a rare RAG1/2‐mediated recombination signal sequence‐like DNA edition in DUX4/IGH target genes. Supportively, shRNA knock‐down of RAG1/2 in leukemic Reh cells consistently impaired the biogenesis of ERGalt, CLEC12Aalt, and C6orf89alt.
Conclusions
All these results suggest that DUX4/IGH‐driven DNA crosslinking is required for RAG1/2 recruitment onto the double tandem DRE‐DRE sites, catalyzing V(D)J‐like recombination and oncogenic splicing in acute lymphoblastic leukemia.
Multiple myeloma (MM) is the second most common hematological malignancy. With the continuous advent of new drugs, the survival of MM patients has been significantly improved, with a median survival ...of 7-10 years. However, the overall survival of high-risk MM patients is still less than 3 years, and extending the survival of high-risk MM has always been a hot topic in this field. The National Comprehensive Cancer Network (NCCN) released the 2nd version of the MM guidelines for 2023 (2023. v2). Compared with the 5th edition of the MM guidelines for 2022, the update of this guideline in diagnosis is mainly reflected in the detailed description of high-risk MM in tabular form, including both cytogenetic high-risk factors containing 1q21 gain/amplification and clinical high-risk factors, such as extramedullary disease, renal failure and weakness. In terms of treatment, the updated guideline still emphasizes the importance of autologous hematopoietic stem cell transplantation in the era of new drugs, and indicates
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