Immune checkpoint molecule DNAM-1/CD112 axis is a novel target for natural killer-cell therapy in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a hematologic malignancy that frequently relapses, even if remission can be achieved with intensive chemotherapy. One known relapse mechanism is the escape of leukemic cells from immune surveillance. Currently, there is no effective immunotherapy for AML because of the lack of specific antigens. Here, we aimed to elucidate the association between CD155 and CD112 in AML cell lines and primary AML samples and determine the therapeutic response. Briefly, we generated NK-92 cell lines (NK-92) with modified DNAX-associated molecule 1 (DNAM-1) and T-cell immunoglobulin and ITIM domain (TIGIT), which are receptors of CD155 and CD112, respectively. Analysis of 200 cases of AML indicated that the survival of patients with high expression of CD112 was shorter than that of patients with low expression. NK-92 DNAM-1 exhibited enhanced cytotoxic activity against AML cell lines and primary cells derived from patients with AML. DNAM-1 induction in NK-92 cells enhanced the expression of cytotoxicity-related genes, thus overcoming the inhibitory activity of TIGIT. Between CD155 and CD112, CD112 is an especially important target for natural killer (NK)-cell therapy of AML. Using a xenograft model, we confirmed the enhanced antitumor effect of NK-92 DNAM-1 compared with that of NK-92 alone. We also discovered that CD112 (Nectin-2), an immune checkpoint molecule belonging to the Nectin/Nectin-like family, functions as a novel target of immunotherapy. In conclusion, modification of the DNAM-1/CD112 axis in NK cells may be an effective novel immunotherapy for AML. Furthermore, our findings suggest that the levels of expression of these molecules are potential prognostic markers in AML.

RUNX1 transactivates BCR-ABL1 expression in Philadelphia chromosome positive acute lymphoblastic leukemia.

The emergence of tyrosine kinase inhibitors as part of a front-line treatment has greatly improved the clinical outcome of the patients with Ph+ acute lymphoblastic leukemia (ALL). However, a portion of them still become refractory to the therapy mainly through acquiring mutations in the BCR-ABL1 gene, necessitating a novel strategy to treat tyrosine kinase inhibitor (TKI)-resistant Ph+ ALL cases. In this report, we show evidence that RUNX1 transcription factor stringently controls the expression of BCR-ABL1, which can strategically be targeted by our novel RUNX inhibitor, Chb-M'. Through a series of in vitro experiments, we identified that RUNX1 binds to the promoter of BCR and directly transactivates BCR-ABL1 expression in Ph+ ALL cell lines. These cells showed significantly reduced expression of BCR-ABL1 with suppressed proliferation upon RUNX1 knockdown. Moreover, treatment with Chb-M' consistently downregulated the expression of BCR-ABL1 in these cells and this drug was highly effective even in an imatinib-resistant Ph+ ALL cell line. In good agreement with these findings, forced expression of BCR-ABL1 in these cells conferred relative resistance to Chb-M'. In addition, in vivo experiments with the Ph+ ALL patient-derived xenograft cells showed similar results. In summary, targeting RUNX1 therapeutically in Ph+ ALL cells may lead to overcoming TKI resistance through the transcriptional regulation of BCR-ABL1. Chb-M' could be a novel drug for patients with TKI-resistant refractory Ph+ ALL.

[Mechanism of action and clinical results of immunotherapy for multiple myeloma].

Treatment outcomes for multiple myeloma (MM) have improved due to the introduction of autologous stem cell transplantation and novel drugs. However, many patients develop resistance to existing therapies; hence, novel treatment strategies for these patients must be established. Therapeutic antibodies, including daratumumab and isatuximab targeting CD38 and elotuzumab targeting SLAMF7, have been introduced as immunotherapies for MM. These antibodies exert cytotoxic effects on myeloma cells through the activation of effectors such as natural killer cells and complement, and induction of phagocytosis by macrophages. Suppressed anti-tumor immunity may be related to acquisition of drug resistance by myeloma cells in patients with MM. It has been reported that the effect of therapeutic antibodies is through the stimulation of anti-tumor immunity. Thus, as each therapeutic antibody displays its own mechanism of action, therapy based on this mechanism of action should be introduced. Furthermore, chimeric antigen receptor (CAR) T-cell therapy, antibody drug conjugates (ADC), and bispecific antibodies (BsAbs) are gradually being introduced as novel immunotherapies for MM. CAR T-cells with high proliferation levels and persistence in recipients to improve the duration of therapeutic response are currently being developed.

Circulating cell-free DNA in the peripheral blood plasma of patients is an informative biomarker for multiple myeloma relapse.

BACKGROUND: Multiple myeloma (MM) is an incurable hematological malignancy. Despite the introduction of several novel drugs, most patients relapse. Biomarkers to identify the early signs of relapse will make it possible to adjust the therapeutic strategy before the disease worsens. Although understanding genetic changes is important for the treatment of MM, currently known biomarkers of relapse, including serum free-light chains and monoclonal paraproteins, are not associated with genetic changes. METHODS: We therefore performed a multicenter study to examine the usefulness of circulating cell-free DNA (cfDNA) present in the peripheral blood (PB) plasma of patients as a biomarker for MM relapse. RESULTS: We identified several driver mutations by combined analysis of next-generation sequencing and existing databases of candidate oncogenes. Furthermore, relapse was detected more sensitively by monitoring the circulating cfDNA with these driver mutations than by conventional serum free-light chain examination. CONCLUSION: These results suggest the potential utility of cfDNA in the PB plasma of patients as a relevant early biomarker for MM relapse.

[Current status and future prospects of immunotherapy for multiple myeloma].

The introduction of autologous stem cell transplantation, proteasome inhibitors, and immunomodulatory drugs (IMiDs) has improved the treatment outcome for multiple myeloma (MM). However, many patients develop resistance to existing therapies, and novel treatment strategies for these patients must be established. Therapeutic antibodies including daratumumab targeting CD38 and elotuzumab targeting SLAMF7 have been introduced in the clinic as immunotherapies for MM. These antibodies exert cytotoxic effects on myeloma cells through the activation of effector cells such as natural killer cells and induction of phagocytosis by macrophages. Suppressed anti-tumor immunity may be related to acquisition of drug resistance by myeloma cells in patients with MM. It has been reported that IMiDs such as lenalidomide and pomalidomide enhance the effect of therapeutic antibodies through the stimulation of anti-tumor immunity. This stimulation of anti-tumor immunity is also observed in the effects of anti-CD38 antibodies, such as daratumumab and isatuximab. Therefore, it is expected that combination therapy with anti-CD38 antibodies and IMiDs may enhance anti-tumor immunity. Furthermore, chimeric antigen receptor (CAR) T cell therapy, antibody drug conjugates (ADC), and bispecific antibodies (BsAbs) are in the process of their introduction to the clinic as novel immunotherapies for MM.

[Cooccurrence of classic Hodgkin lymphoma and multiple myeloma].

Although classic Hodgkin's lymphoma (CHL) sometimes develops after treatment for multiple myeloma (MM), simultaneous diagnosis of both malignancies is extremely rare without previous treatment history. Here we describe a case of a 54-year-old female who complained of left cervical lymphadenopathy. Biopsy specimen from the left cervical lymph node revealed mixed-cellularity CHL. Bone marrow aspirate comprised 10.3% plasma cells. She was diagnosed with MM due to involved: uninvolved serum free light chain ratio of >100. She achieved complete response for CHL after 4 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy along with 30 Gy of involved-field radiotherapy. Three years later, bortezomib, lenalidomide, and dexamethasone (VRd-lite) therapy was initiated for MM. Severe neutropenia during her 1st cycle prompted a dosage reduction of lenalidomide and bortezomib. Partial response was achieved after 4 cycles of VRd-lite followed by high-dose melphalan/autologous stem cell transplantation. No severe adverse events were recorded. This was followed by 4 cycles of carfilzomib, lenalidomide, and dexamethasone therapy, which resulted in complete remission. As the number of elderly people increases, multiple myeloma patients with previous history of other malignancies would increase. Our case has shown that VRd-lite therapy may be suitable for those patients.

UGGT1 retains proinsulin in the endoplasmic reticulum in an arginine dependent manner.

We sought to clarify a pathway by which L- and dD-arginine simulate insulin secretion in mice and cell lines and obtained the following novel two findings. (1) Using affinity magnetic nanobeads technology, we identified that proinsulin is retained in the endoplasmic reticulum (ER) through UDP-glucose:glycoprotein glucosyltransferase 1 (UGGT1) when arginine availability is limited. (2) L- and d-arginine release proinsulin from UGGT1 through competition with proinsulin and promote exit of proinsulin from the ER to Golgi apparatus. The ability of arginine to release proinsulin from UGGT1 closely correlates with arginine-induced insulin secretion in several models of ß cells indicating that UGGT1-proinsulin interaction regulates arginine-induced insulin secretion.

Correction to: Fractionated ifosfamide, carboplatin, and etoposide with rituximab as a safe and effective treatment for relapsed/refractory diffuse large B cell lymphoma with severe comorbidities.

In the published online paper, the data "p = 0.144" was not deleted from the line "Median and mean number of prior treatments (range)" in Table 4.

Fractionated ifosfamide, carboplatin, and etoposide with rituximab as a safe and effective treatment for relapsed/refractory diffuse large B cell lymphoma with severe comorbidities.

Although treatment outcomes for diffuse large B cell lymphoma (DLBCL) have improved with the introduction of rituximab, approximately half of patients experience relapsed/refractory (r/r) disease. Furthermore, no standard salvage therapy has yet been established to date, while limitations in treatment options exist due to toxicity and restricted tolerability among elderly patients and/or those with comorbidities. The ICE (ifosfamide, cyclophosphamide, and etoposide) regimen is often used as salvage therapy for r/r DLBCL. Several modified ICE regimens not requiring continuous ifosfamide infusion are available, which can be used in outpatient clinics. This study analyzed the efficacy and toxicity of fractionated ICE with rituximab (f-R-ICE) as a salvage regimen among 47 patients with relapsed/refractory DLBCL (median age upon f-R-ICE initiation, 71 years). The whole cohort had an overall (ORR) and complete response rate of 53.1% (n = 25) and 25.5% (n = 12), respectively, and an estimated 1-year overall survival after f-R-ICE initiation of 57%. Comorbidities were evaluated using the Charlson Comorbidity Index (CCI) upon f-R-ICE initiation. Patients with low CCI scores (68%) had a higher ORR than those with high CCI scores (36.4%) upon f-R-ICE initiation (P = 0.042). In contrast, no significant differences in overall survival (OS) were observed between the low and high CCI groups (1-year OS 56.6% vs. 52.2%; median OS 24 vs. 22.8 months) after initiating f-R-ICE. Our results suggest that f-R-ICE is a safe and effective salvage therapy for r/r DLBCL and can be used for older patients and/or those with high CCI scores in outpatient clinics.

High Prevalence of Left Ventricular Non-Compaction and Its Effect on Chemotherapy-Related Cardiac Dysfunction in Patients With Hematological Diseases.

BACKGROUND: Recent progress in chemotherapy has prolonged the survival of patients with hematological diseases, but has also increased the number of patients with chemotherapy-related cardiac dysfunction (CTRCD). However, the causes of individual variations and risk factors for CTRCD have yet to be fully elucidated.Methods and Results:Consecutive echocardiograms of 371 patients were retrospectively evaluated for the presence of left ventricular (LV) non-compaction (LVNC). Individual LV ejection fraction (LVEF) outcome estimates were made using bivariate linear regression with log-transformed duration Akaike information criterion (AIC) model fitting. The prevalence of LVNC was 6-fold higher in patients with hematological diseases than in those with non-hematological diseases (12% vs. 2%; risk ratio 6.1; 95% confidence interval [CI] 2.0, 18.2). Among patients with hematological diseases, the ratio of myeloid diseases was significantly higher in the group with LVNC (P=0.031). Deterioration of LVEF was more severe in patients with than without LVNC (-14.4 percentage points/year [95% CI -21.0, -7.9] vs. -4.6 percentage points/year [95% CI -6.8, -2.4], respectively), even after multivariate adjustment for baseline LVEF, background disease distributions, cumulative anthracycline dose, and other baseline factors. CONCLUSIONS: LVNC is relatively prevalent in patients with hematological diseases (particularly myeloid diseases) and can be one of the major risk factors for CTRCD. Detailed cardiac evaluations including LVNC are recommended for patients undergoing chemotherapy.

Hypersensitivity reaction to ß-lactam antibiotics in patients with adult T-cell leukemia/lymphoma treated with mogamulizumab
.

Mogamulizumab (MOG) is a humanized anti-CCR4 monoclonal antibody that is highly cytotoxic for adult T-cell leukemia/lymphoma (ATL) cells. Most non-hematological adverse events are cutaneous adverse reactions in ATL patients. We reviewed the medical records of 24 patients with CCR4-positive aggressive ATL who had received MOG treatment. The incidence of MOG-induced cutaneous adverse reactions (MCARs) was 25% (6 patients). Four patients with MCAR had an interesting clinical course, compared with MCARs reported in previous reports. The factors causing MCAR were suspected to be cefepime, cefozopran, and piperacillin/tazobactam. We consider that hypersensitivity reaction to ß-lactam antibiotics is involved in a significant proportion of MCARs.
.

[Autologous peripheral blood stem cell transplantation for double-refractory myeloma with K-RAS and N-RAS mutations].

The prognosis of multiple myeloma (MM) has been improved due to the introduction of novel agents like proteasome inhibitors and immunomodulatory drugs (IMiDs). However, some cases are refractory to the use of novel agents, and the prognosis of such cases is poor. A 53-year-old male was diagnosed with MM and categorized as follows: Bence-Jones protein lambda type MM, Durie-Salmon IIIA, international staging system (ISS) stage II, and revised ISS stage II. Mutations in K-RAS and IGH/FGFR3 translocation were detected at diagnosis. His tumor was refractory to seven therapeutic regimens including bortezomib, IMiDs (lenalidomide, thalidomide, pomalidomide), conventional chemotherapy, and radiation therapy. N-RAS mutations, CKS1B gains, and C-MYC split signals were detected after treatment. We performed high-dose melphalan/autologous stem cell transplantation (HD-MEL/ASCT) as a salvage therapy and achieved very good partial response. The correlation between K-RAS mutations and poor prognosis or between N-RAS mutations and reduced sensitivity to bortezomib is reported. However, RAS mutations are reported as a favorable factor for HD-MEL/ASCT. In general, mutations of both the K-RAS and N-RAS are known to be mutually exclusive. This rare MM case has mutations in both K-RAS and N-RAS, and the possible relevance of these mutations to both the refractoriness to novel therapies and sensitivity to HD-MEL/ASCT is suggested.

Action mechanisms of histone deacetylase inhibitors in the treatment of hematological malignancies.

Histone deacetylases (HDACs) critically regulate gene expression by determining the acetylation status of histones. Studies have increasingly focused on the activities of HDACs, especially involving non-histone proteins, and their various biological effects. Aberrant HDAC expression observed in several kinds of human tumors makes HDACs potential targets for cancer treatment. Several preclinical studies have suggested that HDAC inhibitors show some efficacy in the treatment of acute myelogenous leukemia with AML1-ETO, which mediates transcriptional repression through its interaction with a complex including HDAC1. Recurrent mutations in epigenetic regulators are found in T-cell lymphomas (TCLs), and HDAC inhibitors and hypomethylating agents were shown to act cooperatively in the treatment of TCLs. Preclinical modeling has suggested that persistent activation of the signal transducer and activator of transcription signaling pathway could serve as a useful biomarker of resistance to HDAC inhibitor in patients with cutaneous TCL. Panobinostat, a pan-HDAC inhibitor, in combination with bortezomib and dexamethasone, has achieved longer progression-free survival in patients with relapsed/refractory multiple myeloma (MM) than the placebo in combination with bortezomib and dexamethasone. Panobinostat inhibited MM cell growth by degrading protein phosphatase 3 catalytic subunit α (PPP3CA), a catalytic subunit of calcineurin. This degradation was suggested to be mediated by the blockade of the chaperone function of heat shock protein 90 due to HDAC6 inhibition. Aberrant PPP3CA expression in advanced MM indicated a possible correlation between high PPP3CA expression and the pathogenesis of MM. Furthermore, PPP3CA was suggested as a common target of panobinostat and bortezomib.

Incidence and clinical background of hepatitis B virus reactivation in multiple myeloma in novel agents' era.

There are some reports regarding hepatitis B virus (HBV) reactivation in patients with myeloma who are HBV carriers or who have had a resolved HBV infection, and there is no standard prophylaxis strategy for these patients. We performed a retrospective multicenter study to determine the incidence and characteristics of HBV reactivation in patients with multiple myeloma. We identified 641 patients with multiple myeloma who had been treated using novel agents and/or autologous stem cell transplantation with high-dose chemotherapy between January 2006 and June 2014 at nine Japanese hospitals. The patients' characteristics, laboratory data, and clinical courses were retrieved and statistically analyzed. During a median follow-up of 101 weeks, one of eight (12.5 %) HBV carriers developed hepatitis and 9 of 99 (9.1 %) patients with resolved HBV infection experienced HBV reactivation; the cumulative incidences of HBV reactivation at 2 years (104 weeks) and 5 years (260 weeks) were 8 and 14 %, respectively. The nine cases of reactivation after resolved HBV infection had received entecavir as preemptive therapy or were carefully observed by monitoring their HBV DNA levels, and none of these cases developed hepatitis. Among patients with multiple myeloma, HBV reactivation was not rare. Therefore, long-term monitoring of HBV DNA levels is needed to prevent hepatitis that is related to HBV reactivation in these patients.

Intracellular reactive oxygen species mark and influence the megakaryocyte-erythrocyte progenitor fate of common myeloid progenitors.

While most studies regarding reactive oxygen species (ROS) focus on their deleterious biological effects, a growing body of evidence indicates the importance of ROS as critical mediators of several signaling pathways, including those involved in hematopoiesis. In this study, we show the critical role of ROS in lineage decision of myeloid progenitors. In megakaryocyte-erythrocyte progenitor cells (MEP), intracellular ROS levels were found to be as low as those in hematopoietic stem cells (HSC). In contrast, remarkably high intracellular ROS levels were observed in granulocyte-monocyte progenitor cells. Intracellular ROS levels in common myeloid progenitors (CMP) were inversely correlated with their MEP differentiation potential. Moreover, gene set enrichment analysis revealed that ROS-low CMP showed gene expression patterns similar to those of MEP, indicating that intracellular ROS levels mark the fate of CMP. In in vitro assays, ROS significantly suppressed the generation of MEP and the formation of megakaryocyte-erythrocyte colonies from CMP. In ROS-high CMP, expression of colony-stimulating factor one receptor (CSF1R) was highly upregulated, and its surface expression correlated with their granulocyte-monocyte differentiation potential. Furthermore, ROS was found to induce the expression of CSF1R mRNA in a leukemia cell line. These data provide novel insights into the relationship between ROS and the hematopoietic differentiation system.

[AML treatment strategy based on cytogenetic abnormalities and somatic mutations].

In addition to morphological and histocytochemical analyses of acute myeloid leukemia (AML), data on cytogenetic abnormalities and somatic mutations are used for classification of AML. The risk stratification based on these examinations facilitates determining the treatment strategy for AML. Cytogenetic risk category definitions by the Southwest Oncology Group (SWOG), Cancer and Leukemia Group B (CALGB), and The Medical Research Council (MRC) classify AML patients into favorable, intermediate, and adverse groups. Approximately 80% of patients in the intermediate group have a normal karyotype and the importance of molecular genetic analyses in these patients is increasing. Somatic mutations of NPM1, CEBPA, and FLT3 are known to be related to the prognosis of AML patients. The European LeukemiaNet (ELN) introduced risk stratification for AML patients based on cytogenetic abnormalities and NPM1, CEBPA, and FLT3 mutations. This risk stratification can be used to select only chemotherapy or chemotherapy with allogeneic hematopoietic stem cell transplantation as consolidation therapy for individual AML patients. Development of molecular targeted therapies against FLT3 or IDH mutations is in progress and these novel therapies are expected to contribute to improving the prognosis of AML patients.

[Discovered roles of MLL in pathogenesis of multiple myeloma].

Multiple myeloma is one of incurable hematological malignancies and targeted therapies for novel oncogenes are to be exploited. Analyses of multiple myeloma patients revealed that HOXA9 was overexpressed in patients lacking known IgH translocation and it was evaluated as a candidate oncogene in multiple myeloma. This overexpression of HOXA9 was supposed to be due to dysfunction of histone methyltransferases (HMT) and mutations in MLL encoding HMT were found. Panobinostat, an HDAC inhibitor is currently undergoing preclinical and clinical evaluation as a novel drug for multiple myeloma. We found that panobinostat suppresses expression of MLL protein through modulation of its stability as well as Hsp90 inhibitor. More precise roles of MLL in pathogenesis of multiple myeloma are to be elucidated.

Novel treatment strategies for hematological malignancies in the immunotherapy era.

The introduction of immunotherapies has led to remarkable progress in the treatment of hematological malignancies, including B-cell malignancies such as B-cell lymphoma and multiple myeloma (MM). Although conventional therapeutic antibodies are effective as immunotherapy for newly diagnosed and relapsed/refractory B-cell lymphoma and MM, some cases are resistant. Chimeric antigen receptor (CAR) T-cell therapies targeting B-cell lymphoma and MM have progressed through several generations, and have improved treatment strategies for relapsed/refractory disease. In addition to conventional therapeutic antibodies, bispecific antibodies targeting both tumor cells and T cells have been developed for MM. Both CAR T-cell therapies and bispecific antibodies are effective for heavily treated patients with relapsed/refractory disease. However, most patients treated with these therapies relapse, and serious adverse events like cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are problematic. This Progress in Hematology, "Novel treatment strategies for hematological malignancies in the immunotherapy era," focuses on such limitations and the future outlook for CAR T-cell therapies and bispecific antibodies for B-cell malignancies. The role of NK cells in anti-tumor immunity for AML and various therapeutic strategies for NK-cell therapy in AML is also discussed.

Evolution of natural killer cell-targeted therapy for acute myeloid leukemia.

In hematologic oncology, acute myeloid leukemia (AML) presents a significant challenge due to its complex genetic landscape and resistance to conventional therapies. Despite advances in treatment, including intensive chemotherapy and hematopoietic stem cell transplantation (HSCT), the prognosis for many patients with AML remains poor. Recently, immunotherapy has emerged as a promising approach to improve outcomes by augmenting existing treatments. Natural killer (NK) cells, a subset of innate lymphoid cells, have garnered attention for their potent cytotoxic capabilities against AML cells. In this review, we discuss the role of NK cells in AML immunosurveillance, their dysregulation in patients with AML, and various therapeutic strategies leveraging NK cells in AML treatment. We explore the challenges and prospects associated with NK cell therapy, including approaches to enhance NK cell function, overcome immune evasion mechanisms, and optimize treatment efficacy. Finally, we emphasize the importance of further research to validate and refine patient-first NK cell-based immunotherapies for AML.