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Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

Present in all eukaryotic cells, the integrated stress response (ISR) is a highly coordinated signaling network that controls cellular behavior, metabolism, and survival in response to diverse stresses. The ISR is initiated when any 1 of 4 stress-sensing kinases (protein kinase R-like endoplasmic reticulum kinase [PERK], general control non-derepressible 2 [GCN2], double-stranded RNA-dependent protein kinase [PKR], heme-regulated eukaryotic translation initiation factor 2α kinase [HRI]) becomes activated to phosphorylate the protein translation initiation factor eukaryotic translation initiation factor 2α (eIF2α), shifting gene expression toward a comprehensive rewiring of cellular machinery to promote adaptation. Although the ISR has been shown to play an important role in the homeostasis of multiple tissues, evidence suggests that it is particularly crucial for the development and ongoing health of the pancreas. Among the most synthetically dynamic tissues in the body, the exocrine and endocrine pancreas relies heavily on the ISR to rapidly adjust cell function to meet the metabolic demands of the organism. The hardwiring of the ISR into normal pancreatic functions and adaptation to stress may explain why it is a commonly used pro-oncogenic and therapy-resistance mechanism in pancreatic ductal adenocarcinoma and pancreatic neuroendocrine tumors. Here, we review what is known about the key roles that the ISR plays in the development, homeostasis, and neoplasia of the pancreas., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background & Aims: Alcohol-associated liver disease (ALD) represents a spectrum of alcohol use-related liver diseases. Outside of alcohol abstinence, there are currently no Food and Drug Administration-approved treatments for advanced ALD, necessitating a greater understanding of ALD pathogenesis and potential molecular targets for therapeutic intervention. The ABL-family proteins, including ABL1 and ABL2, are non-receptor tyrosine kinases that participate in a diverse set of cellular functions. We investigated the role of the ABL kinases in alcohol-associated liver disease., Methods: We used samples from patients with ALD compared with healthy controls to elucidate a clinical phenotype. We established strains of liver-specific Abl1 and Abl2 knockout mice and subjected them to the National Institute on Alcohol Abuse and Alcoholism acute-on-chronic alcohol feeding regimen. Murine samples were subjected to RNA sequencing, AST, Oil Red O staining, H&E staining, Western blotting, and quantitative polymerase chain reaction to assess phenotypic changes after alcohol feeding. In vitro modeling in HepG2 cells as well as primary hepatocytes from C57BL6/J mice was used to establish this mechanistic link of ALD pathogenesis., Results: We demonstrate that the ABL kinases are highly activated in ALD patient liver samples as well as in liver tissues from mice subjected to an alcohol feeding regimen. We found that the liver-specific knockout of Abl2, but not Abl1, attenuated alcohol-induced steatosis, liver injury, and inflammation. Subsequent RNA sequencing and gene set enrichment analyses of mouse liver tissues revealed that relative to wild-type alcohol-fed mice, Abl2 knockout alcohol-fed mice exhibited numerous pathway changes, including significantly decreased peroxisome proliferator activated receptor (PPAR) signaling. Further examination revealed that PPARγ, a previously identified regulator of ALD pathogenesis, was induced upon alcohol feeding in wild-type mice, but not in Abl2 knockout mice. In vitro analyses revealed that shRNA-mediated knockdown of ABL2 abolished the alcohol-induced accumulation of PPARγ as well as subsequent lipid accumulation. Conversely, forced overexpression of ABL2 resulted in increased PPARγ protein expression. Furthermore, we demonstrated that the regulation of hypoxia inducible factor 1 subunit alpha (HIF1α) by ABL2 is required for alcohol-induced PPARγ expression. Furthermore, treatment with ABL kinase inhibitors attenuated alcohol-induced PPARγ expression, lipid droplet formation, and liver injury., Conclusions: On the basis of our current evidence, we propose that alcohol-induced ABL2 activation promotes ALD through increasing HIF1α and the subsequent PPARγ expression, and ABL2 inhibition may serve as a promising target for the treatment of ALD., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Lenvatinib is a multikinase inhibitor approved as a first-line therapy for advanced hepatocellular carcinoma (HCC). However, the development of drug resistance is common, and the underlying mechanisms governing this resistance are largely unknown. In this study, we established two lenvatinib-resistant (LR) HCC cell lines and identified integrin subunit beta 8 (ITGB8) as a critical contributor to lenvatinib resistance in HCC. The elevated expression of ITGB8 was observed in LR HCC cells. Furthermore, silencing of ITGB8 reversed lenvatinib resistance in vitro and in vivo, whereas ectopic expression of ITGB8 in lenvatinib-sensitive parental HCC cells exhibited increased resistance to lenvatinib. Mechanistically, ITGB8 regulated lenvatinib resistance through an HSP90-mediated stabilization of AKT and enhanced AKT signaling. In support of this model, either an AKT inhibitor MK-2206 or an HSP90 inhibitor 17-AAG resensitized LR HCC cells to lenvatinib treatment. Conclusion: Collectively, our results establish a crucial role of ITGB8 in lenvatinib resistance, and suggest that targeting the ITGB8/HSP90/AKT axis is a promising therapeutic strategy in patients with HCC exhibiting lenvatinib resistance., (© 2022 The Authors. Hepatology Communications published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)

Hepatocellular carcinoma (HCC) is a highly lethal and complex malignancy strongly influenced by the surrounding tumor microenvironment. The HCC microenvironment comprises hepatic stellate cells (HSCs), tumor-associated macrophages (TAMs), stromal and endothelial cells, and the underlying extracellular matrix (ECM). Emerging evidence demonstrates that epigenetic regulation plays a crucial role in altering numerous components of the HCC tumor microenvironment. In this review, we summarize the current understanding of the mechanisms of epigenetic regulation of the microenvironment in HCC. We review recent studies demonstrating how specific epigenetic mechanisms (DNA methylation, histone regulation, and non-coding RNAs mediated regulation) in HSCs, TAMs, and ECM, and how they contribute to HCC development, so as to gain new insights into the treatment of HCC via regulating epigenetic regulation in the tumor microenvironment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Malnassy and Qiu.)

Retrospective studies have suggested that older adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) have better survival rates when treated using a pediatric ALL regimen administered by pediatric treatment teams. To address the feasibility and efficacy of using a pediatric treatment regimen for AYA patients with newly diagnosed ALL administered by adult treatment teams, we performed a prospective study, CALGB 10403, with doses and schedule identical to those in the Children's Oncology Group study AALL0232. From 2007 to 2012, 318 patients were enrolled; 295 were eligible and evaluable for response. Median age was 24 years (range, 17-39 years). Use of the pediatric regimen was safe; overall treatment-related mortality was 3%, and there were only 2 postremission deaths. Median event-free survival (EFS) was 78.1 months (95% confidence interval [CI], 41.8 to not reached), more than double the historical control of 30 months (95% CI, 22-38 months); 3-year EFS was 59% (95% CI, 54%-65%). Median overall survival (OS) was not reached. Estimated 3-year OS was 73% (95% CI, 68%-78%). Pretreatment risk factors associated with worse treatment outcomes included obesity and presence of the Philadelphia-like gene expression signature. Use of a pediatric regimen for AYAs with ALL up to age 40 years was feasible and effective, resulting in improved survival rates compared with historical controls. CALGB 10403 can be considered a new treatment standard upon which to build for improving survival for AYAs with ALL. This trial was registered at www.clinicaltrials.gov as #NCT00558519., (© 2019 by The American Society of Hematology.)

Hepatocellular carcinoma (HCC) is the fifth most common primary cancer and second largest cause of cancer-related death worldwide. The first-line oral chemotherapeutic agent sorafenib only increases survival in patients with advanced HCC by less than 3 months. Most patients with advanced HCC have shown limited response rates and survival benefits with sorafenib. Although sorafenib is an inhibitor of multiple kinases, including serine/threonine-protein kinase c-Raf, serine/threonine-protein kinase B-Raf, vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, VEGFR-3, and platelet-derived growth factor receptor β, HCC cells are able to escape from sorafenib treatment using other pathways that the drug insufficiently inhibits. The aim of this study was to identify and target survival and proliferation pathways that enable HCC to escape the antitumor activity of sorafenib. We found that insulin-like growth factor 1 receptor (IGF1R) remains activated in HCC cells treated with sorafenib. Knockdown of IGF1R sensitizes HCC cells to sorafenib treatment and decreases protein kinase B (AKT) activation. Overexpression of constitutively activated AKT reverses the effect of knockdown of IGF1R in sensitizing HCC cells to treatment with sorafenib. Further, we found that ceritinib, a drug approved by the U.S. Food and Drug Administration for treatment of non-small cell lung cancer, effectively inhibits the IGF1R/AKT pathway and enhances the inhibitory efficacy of sorafenib in human HCC cell growth and survival in vitro , in a xenograft mouse model and in the c-Met/β-catenin-driven HCC mouse model. Conclusion : Our study provides a biochemical basis for evaluation of a new combination treatment that includes IGF1R inhibitors, such as ceritinib and sorafenib, in patients with HCC. ( Hepatology Communications 2018;2:732-746).

Background: The optimal strategy for vaccination to induce CD8 + T cell responses against WT1 is not known., Methods: A pilot randomized study in HLA-A02 + patients to receive vaccination with WT1 in Montanide or in poly ICLC, a TLR3 agonist, to explore the novel immune adjuvant was conducted. Seven patients were randomized. Four patients received WT1 in Montanide, and three with WT1 in poly ICLC. Five patients were in morphologic remission and two had residual morphologic disease at the study entry., Results: All patients finished the induction phase without any major toxicity except mild transient local injection reaction. One patient on the Montanide arm developed aseptic ulceration at two vaccine sites which healed without antibiotics. Three of 4 patients on the Montanide arm had a decreased expression of WT1 after WT1 vaccination, and two of them demonstrated generation of WT1-specific cytotoxic CD8 + T cell responses with biased TCR beta chain enrichment. In contrast, no obvious WT1-specific immune responses were detected in two patients on the poly ICLC arm, nor was there clonal enrichment by TCR alpha/beta sequencing; however, these patients did also have decreased WT1 expression and remained in remission several years after the initiation of treatment., Conclusions: WT1 peptide vaccine with Montanide as an adjuvant induces detectable WT1-specific CD8 + T cell responses with clonal TCR enrichment, which may be capable of controlling leukemia recurrence in the setting of minimal residual disease. Poly ICLC may induce anti-leukemic activity in the absence of detectable WT1 specific CD8 + T cell responses. Trial registration NCT01842139, 7/3/2012 retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT01842139.

Gain-of-function mutations of FLT3 (FLT3-ITD), comprises up to 30% of normal karyotype acute myeloid leukemia (AML) and is associated with an adverse prognosis. Current FLT3 kinase inhibitors have been tested extensively, but have not yet resulted in a survival benefit and novel therapies are awaited. Here we show that T-LAK cell-originated protein kinase (TOPK), a mitotic kinase highly expressed in and correlated with more aggressive phenotype in several types of cancer, is expressed in AML but not in normal CD34+ cells and that TOPK knockdown decreased cell viability and induced apoptosis. Treatment of AML cells with TOPK inhibitor (OTS514) resulted in a dose-dependent decrease in cell viability with lower IC50 in FLT3-mutated cells, including blasts obtained from patients relapsed after FLT3-inhibitor treatment. Using a MV4-11-engrafted mouse model, we found that mice treated with 7.5 mg/kg IV daily for 3 weeks survived significantly longer than vehicle treated mice (median survival 46 vs 29 days, P < 0.001). Importantly, we identified TOPK as a FLT3-ITD and CEBPA regulated kinase, and that modulating TOPK expression or activity resulted in significant decrease of FLT3 expression and CEBPA phosphorylation. Thus, targeting TOPK in FLT3-ITD AML represents a novel therapeutic approach for this adverse risk subset of AML.

Although recent progress in understanding the biology and optimizing the treatment of acute lymphoblastic leukemia (ALL) has improved cure rates of childhood ALL to nearly 90%, the cure rate in adult ALL remains less than 50%. The poor prognosis in adult ALL has in part been attributed to larger proportion of high-risk leukemia showing drug resistance. Thus, identifying novel therapeutic targets in ALL is needed for further improvements in treatment outcomes of adult ALL. Genetic aberration of chromatin-modifying molecules has been recently reported in subtypes of ALL, and targeting components of chromatin complexes has shown promising efficacy in preclinical studies. Suppressor of variegation 3-9 homologue 2 (SUV39H2), also known as KMT1B, is a SET-domain-containing histone methyltransferase that is upregulated in solid cancers, but its expression is hardly detectable in normal tissues. Here, we show that SUV39H2 is highly expressed in ALL cells but not in blood cells from healthy donors and also that SUV39H2 mRNA is expressed at significantly higher levels in bone marrow or blood cells from patients with ALL obtained at diagnosis compared with those obtained at remission (P = .007). In four ALL cell lines (Jurkat and CEM derived from T-ALL and RS4;11 and REH derived from B-ALL), SUV39H2 knockdown resulted in a significant decrease in cell viability (~77%, P < .001), likely through induction of apoptosis. On the other hand, SUV39H2 overexpression made cells more resistant to chemotherapy. We conclude that SUV39H2 is a promising therapeutic target and further investigation of this therapeutic approach in ALL is warranted., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Background We hypothesized that targeting two mechanisms of epigenetic silencing would be additive or synergistic with regard to expression of specific target genes. The primary objective of the study was to establish the maximum tolerated dose (MTD) of belinostat in combination with a fixed dose of azacitidine (AZA). Methods In Part A of the study, patients received a fixed dose of AZA, with escalating doses of belinostat given on the same days 1-5, in a 28 day cycle. Part B was designed to evaluate the relative contribution of belinostat to the combination based on analysis of pharmacodynamic markers, and incorporated a design in which patients were randomized during cycle 1 to AZA alone, or the combination, at the maximally tolerated dose of belinostat. Results 56 patients with myeloid neoplasia were enrolled. Dose escalation was feasible in part A, up to 1000 mg/m(2) dose level of belinostat. In Part B, 18 patients were assessable for quantitative analysis of specific target genes. At day 5 of therapy, MDR1 was significantly up-regulated in the belinostat/AZA arm compared with AZA alone arm (p = 0.0023). There were 18 responses among the 56 patients. Conclusions The combination of belinostat and AZA is feasible and associated with clinical activity. The recommended phase II dose is 1000 mg/m(2) of belinostat plus 75 mg/m(2) of AZA on days 1-5, every 28 days. Upregulation in MDR1 was observed in the combination arm at day 5 compared with the AZA alone arm, suggesting a relative biologic contribution of belinostat to the combination.

Maternal embryonic leucine-zipper kinase (MELK), which was reported to be frequently up-regulated in various types of solid cancer, plays critical roles in formation and maintenance of cancer stem cells. However, little is known about the relevance of this kinase in hematologic malignancies. Here we report characterization of possible roles of MELK in acute myeloid leukemia (AML). MELK is expressed in AML cell lines and AML blasts with higher levels in less differentiated cells. MELK is frequently upregulated in AML with complex karyotypes and is associated with worse clinical outcome. MELK knockdown resulted in growth inhibition and apoptosis of leukemic cells. Hence, we investigated the potent anti-leukemia activity of OTS167, a small molecule MELK kinase inhibitor, in AML, and found that the compound induced cell differentiation and apoptosis as well as decreased migration of AML cells. MELK expression was positively correlated with the expression of FOXM1 as well as its downstream target genes. Furthermore, MELK inhibition resulted in downregulation of FOXM1 activity and the expression of its downstream targets. Taken together, and given that OTS167 is undergoing a phase I clinical trial in solid cancer, our study warrants clinical evaluation of this compound as a novel targeted therapy for AML patients.

Tyrosine kinase inhibitor therapy with imatinib (IM), dasatinib (DAS), or nilotinib is very effective in chronic-phase chronic myeloid leukemia. Two hundred fifty-three patients with newly diagnosed chronic-phase chronic myeloid leukemia were randomized to IM 400 mg/day or DAS 100 mg/day. The proportion of patients achieving a complete cytogenetic remission rate was superior with DAS (84% vs 69%), as was the 12-month molecular response by the proportions of patients achieving > 3-log, > 4-log, and > 4.5-log reduction in BCR-ABL transcript levels. Overall and progression-free survival was similar in the 2 arms. Among patients who achieved hematologic CR, 3-year relapse-free survival was 91% with DAS and 88% with IM 400 mg. Grade 3 and 4 toxicities were most commonly hematologic, including thrombocytopenia in 18% and 8% of DAS and IM patients, respectively. DAS induced more complete cytogenetic response and deeper molecular responses after 12 months, compared with IM 400 mg, and with a median follow-up of 3.0 years there have been very few deaths, relapses, or progressions in the 2 arms. In summary, DAS compared with IM appeared to have more short-term cytogenetic and molecular response, more hematologic toxicity, and similar overall survival. This trial is registered at www.clinicaltrials.gov as NCT00070499.

Background: In the present study, the prognostic impact of minimal residual disease during treatment on time to progression and overall survival was analyzed prospectively in patients with mantle cell lymphoma treated on the Cancer and Leukemia Group B 59909 clinical trial., Design and Methods: Peripheral blood and bone marrow samples were collected during different phases of the Cancer and Leukemia Group B 59909 study for minimal residual disease analysis. Minimal residual disease status was determined by quantitative polymerase chain reaction of IgH and/or BCL-1/JH gene rearrangement. Correlation of minimal residual disease status with time to progression and overall survival was determined. In multivariable analysis, minimal residual disease, and other risk factors were correlated with time to progression., Results: Thirty-nine patients had evaluable, sequential peripheral blood and bone marrow samples for minimal residual disease analysis. Using peripheral blood monitoring, 18 of 39 (46%) achieved molecular remission following induction therapy. The molecular remission rate increased from 46 to 74% after one course of intensification therapy. Twelve of 21 minimal residual disease positive patients (57%) progressed within three years of follow up compared to 4 of 18 (22%) molecular remission patients (P=0.049). Detection of minimal residual disease following induction therapy predicted disease progression with a hazard ratio of 3.7 (P=0.016). The 3-year probability of time to progression among those who were in molecular remission after induction chemotherapy was 82% compared to 48% in patients with detectable minimal residual disease. The prediction of time to progression by post-induction minimal residual disease was independent of other prognostic factors in multivariable analysis., Conclusions: Detection of minimal residual disease following induction immunochemotherapy was an independent predictor of time to progression following immunochemotherapy and autologous stem cell transplantation for mantle cell lymphoma.