LKB1/STK11 Is a Tumor Suppressor in the Progression of Myeloproliferative Neoplasms.

The myeloproliferative neoplasms (MPN) frequently progress to blast phase disease, an aggressive form of acute myeloid leukemia. To identify genes that suppress disease progression, we performed a focused CRISPR/Cas9 screen and discovered that depletion of LKB1/Stk11 led to enhanced in vitro self-renewal of murine MPN cells. Deletion of Stk11 in a mouse MPN model caused rapid lethality with enhanced fibrosis, osteosclerosis, and an accumulation of immature cells in the bone marrow, as well as enhanced engraftment of primary human MPN cells in vivo. LKB1 loss was associated with increased mitochondrial reactive oxygen species and stabilization of HIF1α, and downregulation of LKB1 and increased levels of HIF1α were observed in human blast phase MPN specimens. Of note, we observed strong concordance of pathways that were enriched in murine MPN cells with LKB1 loss with those enriched in blast phase MPN patient specimens, supporting the conclusion that STK11 is a tumor suppressor in the MPNs. SIGNIFICANCE: Progression of the myeloproliferative neoplasms to acute myeloid leukemia occurs in a substantial number of cases, but the genetic basis has been unclear. We discovered that loss of LKB1/STK11 leads to stabilization of HIF1a and promotes disease progression. This observation provides a potential therapeutic avenue for targeting progression.This article is highlighted in the In This Issue feature, p. 1307.

FBXO11 is a candidate tumor suppressor in the leukemic transformation of myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) is a heterogeneous myeloid malignancy characterized by blood cell morphological dysplasia, ineffective clonal hematopoiesis, and risk of transformation to secondary acute myeloid leukemia (sAML). A number of genetic abnormalities have been identified in MDS and sAML, but sensitive sequencing methods can detect these mutations in nearly all healthy individuals by 60 years of age. To discover novel cellular pathways that accelerate MDS and sAML, we performed a CRISPR/Cas9 screen in the human MDS-L cell line. We report here that loss of the F-Box protein FBXO11, a component of the SCF ubiquitin ligase complex, confers cytokine independent growth to MDS-L cells, suggesting a tumor suppressor role for FBXO11 in myeloid malignancies. Putative FBXO11 substrates are enriched for proteins with functions in RNA metabolism and, of note, spliceosome mutations that are commonly found in MDS/sAML are rare in patients with low FBXO11 expression. We also reveal that loss of FBXO11 leads to significant changes in transcriptional pathways influencing leukocyte proliferation, differentiation, and apoptosis. Last, we find that FBXO11 expression is reduced in patients with secondary AML. We conclude that loss of FBXO11 is a mechanism for disease transformation of MDS into AML, and may represent a future therapeutic target.

Myelofibrosis in 2019: moving beyond JAK2 inhibition.

Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by ineffective clonal hematopoiesis, splenomegaly, bone marrow fibrosis, and the propensity for transformation to acute myeloid leukemia. The discovery of mutations in JAK2, CALR, and MPL have uncovered activated JAK-STAT signaling as a primary driver of MF, supporting a rationale for JAK inhibition. However, JAK inhibition alone is insufficient for long-term remission and offers modest, if any, disease-modifying effects. Given this, there is great interest in identifying mechanisms that cooperate with JAK-STAT signaling to predict disease progression and rationally guide the development of novel therapies. This review outlines the latest discoveries in the biology of MF, discusses current clinical management of patients with MF, and summarizes the ongoing clinical trials that hope to change the landscape of MF treatment.

Evaluation of the impact of cachexia on clinical outcomes in aggressive lymphoma.

Cancer cachexia is a state of involuntary weight loss and altered body composition triggered by an underlying malignancy. We sought to correlate measures of cachexia with clinical outcomes in aggressive lymphomas and to identify biological pathways involved in the cachexia phenotype for possible druggable targets. Radiographic measures of cachexia were collected in a retrospective cohort of 109 patients with aggressive B-cell lymphoma and followed for clinical outcome. We found males with sarcopenia had reduced progression-free survival (5·4 vs. 72·3 months, P < 0·0005) and overall survival (OS; 30·2 months vs. not reached, NR, P = 0·02); males with adipopenia also had decreased OS (21·6 months vs. NR, P = 0·04). A trend for increased OS was observed in female sarcopenics only (32·8 months vs. NR, P = 0·08). Additionally, we analysed a prospective cohort of 14 patients for differences in circulating molecular targets involved in various biological pathways. There was a significant correlation with cachexia for reduced serum levels of mediators within the glucose utilization [insulin -like growth factor (IGF)-binding protein 6, P = 0·04; IGF-1, P = 0·02], inflammation (lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells; LIGHT, P = 0·005), and energy intake/expenditure (leptin, P = 0·004). We conclude that cachexia in patients with aggressive lymphomas has sex-specific prognostic utility and correlates with measurable changes in metabolism and immune function.

The expanding role of venetoclax in chronic lymphocytic leukemia and small lymphocytic lymphoma.

The BCL-2 protein family members inhibit cellular apoptosis, and their overexpression represents a common survival adaption in cancer. Recently, a selective BCL-2 inhibitor ABT-199, venetoclax, has demonstrated remarkable activity in relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), both as a single agent and in combination with anti-CD20 immunotherapies, such as rituximab. In this article, we review the development and latest clinical data that have led to the expanded approval of venetoclax with rituximab in relapsed/refractory CLL/SLL. We also discuss ongoing and future clinical trials designed to evaluate the efficacy of venetoclax in previously untreated patients and to investigate venetoclax combinations with inhibitors of B-cell receptor signaling pathway. These studies hope to offer an expanded list of chemotherapy-free regimens for patients with CLL/SLL.

Current overview and treatment of mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma with historically poor long-term survival compared with other B-cell malignancies. Treatment strategies for this disease are variable and dependent on symptoms and patient fitness. Despite recent advances, MCL remains incurable and patients with high-risk disease have particularly poor outcomes. This review focuses on recent developments that enhance our understanding of the biology of MCL and new treatment approaches that have led to substantial improvements in clinical outcomes. We will outline induction immuno-chemotherapy and maintenance strategies in transplant-eligible patients. In addition, effective strategies for patients unfit for intensive induction will be discussed, with a particular focus on novel molecular therapies with activity in MCL. Lastly, a number of ongoing clinical trials will be presented; the data from these trials are anticipated to redefine standards of care in the near future.

TCA Cycle and Mitochondrial Membrane Potential Are Necessary for Diverse Biological Functions.

Mitochondrial metabolism is necessary for the maintenance of oxidative TCA cycle function and mitochondrial membrane potential. Previous attempts to decipher whether mitochondria are necessary for biological outcomes have been hampered by genetic and pharmacologic methods that simultaneously disrupt multiple functions linked to mitochondrial metabolism. Here, we report that inducible depletion of mitochondrial DNA (ρ(ο) cells) diminished respiration, oxidative TCA cycle function, and the mitochondrial membrane potential, resulting in diminished cell proliferation, hypoxic activation of HIF-1, and specific histone acetylation marks. Genetic reconstitution only of the oxidative TCA cycle function specifically in these inducible ρ(ο) cells restored metabolites, resulting in re-establishment of histone acetylation. In contrast, genetic reconstitution of the mitochondrial membrane potential restored ROS, which were necessary for hypoxic activation of HIF-1 and cell proliferation. These results indicate that distinct mitochondrial functions associated with respiration are necessary for cell proliferation, epigenetics, and HIF-1 activation.

TOR signaling couples oxygen sensing to lifespan in C. elegans.

Metazoans adapt to a low-oxygen environment (hypoxia) through activation of stress-response pathways. Here, we report that transient hypoxia exposure extends lifespan in C. elegans through mitochondrial reactive oxygen species (ROS)-dependent regulation of the nutrient-sensing kinase target of rapamycin (TOR) and its upstream activator, RHEB-1. The increase in lifespan during hypoxia requires the intestinal GATA-type transcription factor ELT-2 downstream of TOR signaling. Using RNA sequencing (RNA-seq), we describe an ELT-2-dependent hypoxia response that includes an intestinal glutathione S-transferase, GSTO-1, and uncover that GSTO-1 is required for lifespan under hypoxia. These results indicate mitochondrial ROS-dependent TOR signaling integrates metabolic adaptations in order to confer survival under hypoxia.

ROS function in redox signaling and oxidative stress.

Oxidative stress refers to elevated intracellular levels of reactive oxygen species (ROS) that cause damage to lipids, proteins and DNA. Oxidative stress has been linked to a myriad of pathologies. However, elevated ROS also act as signaling molecules in the maintenance of physiological functions--a process termed redox biology. In this review we discuss the two faces of ROS--redox biology and oxidative stress--and their contribution to both physiological and pathological conditions. Redox biology involves a small increase in ROS levels that activates signaling pathways to initiate biological processes, while oxidative stress denotes high levels of ROS that result in damage to DNA, protein or lipids. Thus, the response to ROS displays hormesis, given that the opposite effect is observed at low levels compared with that seen at high levels. Here, we argue that redox biology, rather than oxidative stress, underlies physiological and pathological conditions.

ROS links glucose metabolism to breast cancer stem cell and EMT phenotype.

Cancer stem cells display an epithelial-mesenchymal transition phenotype and are resistant to current therapies. In this issue of Cancer Cell, Dong and colleagues demonstrate that these phenotypes in basal-like breast cancer are promoted by a metabolic switch to glucose metabolism, resulting in decreased reactive oxygen species levels.

Telemedicine in heart failure: pre-specified and exploratory subgroup analyses from the TIM-HF trial.

BACKGROUND: Meta-analyses have suggested that remote telemedical management (RTM) positively affects clinical outcomes in chronic HF patients. The results of two recent randomised RTM trials do not corroborate these results. We aim to report prospectively defined and exploratory subgroup analyses for the TIM-HF trial and to identify a patient profile that could potentially benefit from RTM for further investigation in randomised clinical trials. METHODS: In TIM-HF, 710 stable chronic HF patients, in NYHA class II or III with a history of HF decompensation within 2 years previously or a LVEF ≤ 25% were randomly assigned (1:1) to RTM or usual care. The primary outcome was total death and secondary outcomes included days lost due to death or HF hospitalisation and a composite of cardiovascular death and HF hospitalisation. Twelve subgroups were prospectively defined and patient profiling was investigated for the subgroup with a prior history of HF decompensation, an LVEF ≥ 25% and a PHQ-9 score<10. RESULTS: The subgroup treatment effects were significant for total mortality for the PHQ-9 subgroup only (p for interaction<0.027). For the outcome 'number of days lost due to hospitalisation for HF or death', the subgroup treatment effects were significant (p for interaction<0.05) for patients with a prior HF decompensation or an ICD implant or a PHQ score of <10 and for the patient-profiling subgroup. CONCLUSIONS: Telemedicine management may not be appropriate for all HF patients. Future research needs to investigate which HF population may benefit from this intervention.

Impact of remote telemedical management on mortality and hospitalizations in ambulatory patients with chronic heart failure: the telemedical interventional monitoring in heart failure study.

BACKGROUND: This study was designed to determine whether physician-led remote telemedical management (RTM) compared with usual care would result in reduced mortality in ambulatory patients with chronic heart failure (HF). METHODS AND RESULTS: We enrolled 710 stable chronic HF patients in New York Heart Association functional class II or III with a left ventricular ejection fraction ≤35% and a history of HF decompensation within the previous 2 years or with a left ventricular ejection fraction ≤25%. Patients were randomly assigned (1:1) to RTM or usual care. Remote telemedical management used portable devices for ECG, blood pressure, and body weight measurements connected to a personal digital assistant that sent automated encrypted transmission via cell phones to the telemedical centers. The primary end point was death from any cause. The first secondary end point was a composite of cardiovascular death and hospitalization for HF. Baseline characteristics were similar between the RTM (n=354) and control (n=356) groups. Of the patients assigned to RTM, 287 (81%) were at least 70% compliant with daily data transfers and no break for >30 days (except during hospitalizations). The median follow-up was 26 months (minimum 12), and was 99.9% complete. Compared with usual care, RTM had no significant effect on all-cause mortality (hazard ratio, 0.97; 95% confidence interval, 0.67 to 1.41; P=0.87) or on cardiovascular death or HF hospitalization (hazard ratio, 0.89; 95% confidence interval, 0.67 to 1.19; P=0.44). CONCLUSIONS: In ambulatory patients with chronic HF, RTM compared with usual care was not associated with a reduction in all-cause mortality. CLINICAL TRIAL REGISTRATION: URL: http://www.ClinicalTrials.gov. Unique identifier: NCT00543881.

A new telemonitoring system intended for chronic heart failure patients using mobile telephone technology--feasibility study.

BACKGROUND: Remote monitoring is one modality of structured care in chronic heart failure. The purpose of this study was to evaluate the feasibility of a new wireless telemonitoring system via a mobile phone network. METHODS: Portable home devices for electrocardiogram, blood pressure, body weight and self-assessment measurements were connected (via Bluetooth) to a personal digital assistant (PDA) that performs automated encrypted transmission via mobile phone. Two telemedical centres were set-up. RESULTS: 30 healthy volunteers were enrolled and followed for 26 days. A total of 4002 single measurements were taken, 133 ± 37 per person. No data was lost or incorrectly allocated. 880 of 937 (94%) of the ECG recordings had sufficient diagnostic quality for rhythm analysis and single beat measurements. 50 continuous ECG-streams (312 min) without disruption were performed. Total system availability was 96.6%, including that of the mobile phone network. CONCLUSIONS: Mobile phone technology is suitable for continuous and secure medical data transmission. To evaluate the clinical use in chronic heart failure patients, a large multicentre randomized controlled trial (ClinicalTrials.gov Identifier: NCT00543881) was started.

Telemedical Interventional Monitoring in Heart Failure (TIM-HF), a randomized, controlled intervention trial investigating the impact of telemedicine on mortality in ambulatory patients with heart failure: study design.

AIMS: Remote patient management (telemonitoring) may help to detect early signs of cardiac decompensation, allowing optimization of and adherence to treatments in chronic heart failure (CHF). Two meta-analyses have suggested that telemedicine in CHF can reduce mortality by 30-35%. The aim of the TIM-HF study was to investigate the impact of telemedical management on mortality in ambulatory CHF patients. Methods CHF patients [New York Heart Association (NYHA) II/III, left ventricular ejection fraction (LVEF)≤35%] with a history of cardiac decompensation with hospitalization in the past or therapy with intravenous diuretics in the prior 24 months (no decompensation required if LVEF≤25%) were randomized 1:1 to an intervention group of daily remote device monitoring (electrocardiogram, blood pressure, body weight) coupled with medical telephone support or to usual care led by the patients' local physician. In the intervention group, 24/7 physician-led medical support was provided by two central telemedical centres. A clinical event committee blinded to treatment allocation assessed cause of death and reason for hospitalization. The primary endpoint was total mortality. The first secondary endpoint was a composite of cardiovascular mortality or hospitalization due to heart failure. Other secondary endpoints included cardiovascular mortality, all-cause and cause-specific hospitalizations (all time to first event) as well as days lost due to heart failure hospitalization or cardiovascular death (in % of follow-up time), and changes in quality of life and NYHA class. Overall, 710 CHF patients were recruited. The mean follow-up was 21.5±7.2 months, with a minimum of 12 months. Perspective The study will provide important prospective outcome data on the impact of telemedical management in patients with CHF.

Comparative evaluation of left and right ventricular endomyocardial biopsy: differences in complication rate and diagnostic performance.

BACKGROUND: Endomyocardial biopsy (EMB) represents the gold standard for diagnosing myocarditis and nonischemic cardiomyopathies. This study focuses on the risk of complications and the respective diagnostic performance of left ventricular (LV), right ventricular (RV), or biventricular EMB in patients with suspected myocarditis and/or cardiomyopathy of unknown origin. METHODS AND RESULTS: In this 2-center study, 755 patients with clinically suspected myocarditis (n=481) and/or cardiomyopathy of nonischemic origin including those with infiltrative or connective tissue disease (n=274) underwent either selective LV-EMB (n=265; 35.1%), selective RV-EMB (n=133; 17.6%), or biventricular EMB (n=357; 47.3%) after coronary angiography and exclusion of significant coronary artery disease. Cardiovascular magnetic resonance, including late gadolinium enhancement, imaging was performed in 540 patients (71.5%). The major complication rate for LV-EMB was 0.64% and for RV-EMB, 0.82%. Considering postprocedural pericardial effusion that occurred after biventricular EMB, the minor complication rate for LV-EMB varied between 0.64% to 2.89% and for RV-EMB, between 2.24% and 5.10%. Diagnostic EMB results were achieved significantly more often in those patients who underwent biventricular EMBs (79.3%) compared to those who underwent either selective LV-EMB or selective RV-EMB (67.3%; P<0.001). In patients with biventricular EMB, myocarditis was diagnosed in LV-EMB samples in 18.7% and in RV-EMB samples in 7.9% (P=0.002) , and it was diagnosed in both ventricles in 73.4%. There were no differences in the number of positive LV-EMB, RV-EMB, or LV- and RV-EMB findings when related to the site of cardiovascular magnetic resonance-based late gadolinium enhancement. CONCLUSIONS: Both LV-EMB and RV-EMB are safe procedures if performed by experienced interventionalists. The diagnostic yield of EMB may be optimized when samples from both ventricles are available. Preferential biopsy in regions showing late gadolinium enhancement on cardiovascular magnetic resonance does not increase the number of positive diagnoses of myocarditis.

BNP-guided vs symptom-guided heart failure therapy: the Trial of Intensified vs Standard Medical Therapy in Elderly Patients With Congestive Heart Failure (TIME-CHF) randomized trial.

CONTEXT: It is uncertain whether intensified heart failure therapy guided by N-terminal brain natriuretic peptide (BNP) is superior to symptom-guided therapy. OBJECTIVE: To compare 18-month outcomes of N-terminal BNP-guided vs symptom-guided heart failure therapy. DESIGN, SETTING, AND PATIENTS: Randomized controlled multicenter Trial of Intensified vs Standard Medical Therapy in Elderly Patients With Congestive Heart Failure (TIME-CHF) of 499 patients aged 60 years or older with systolic heart failure (ejection fraction < or = 45%), New York Heart Association (NYHA) class of II or greater, prior hospitalization for heart failure within 1 year, and N-terminal BNP level of 2 or more times the upper limit of normal. The study had an 18-month follow-up and it was conducted at 15 outpatient centers in Switzerland and Germany between January 2003 and June 2008. INTERVENTION: Uptitration of guideline-based treatments to reduce symptoms to NYHA class of II or less (symptom-guided therapy) and BNP level of 2 times or less the upper limit of normal and symptoms to NYHA class of II or less (BNP-guided therapy). MAIN OUTCOME MEASURES: Primary outcomes were 18-month survival free of all-cause hospitalizations and quality of life as assessed by structured validated questionnaires. RESULTS: Heart failure therapy guided by N-terminal BNP and symptom-guided therapy resulted in similar rates of survival free of all-cause hospitalizations (41% vs 40%, respectively; hazard ratio [HR], 0.91 [95% CI, 0.72-1.14]; P = .39). Patients' quality-of-life metrics improved over 18 months of follow-up but these improvements were similar in both the N-terminal BNP-guided and symptom-guided strategies. Compared with the symptom-guided group, survival free of hospitalization for heart failure, a secondary end point, was higher among those in the N-terminal BNP-guided group (72% vs 62%, respectively; HR, 0.68 [95% CI, 0.50-0.92]; P = .01). Heart failure therapy guided by N-terminal BNP improved outcomes in patients aged 60 to 75 years but not in those aged 75 years or older (P < .02 for interaction) CONCLUSION: Heart failure therapy guided by N-terminal BNP did not improve overall clinical outcomes or quality of life compared with symptom-guided treatment. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN43596477.