HSPA8 chaperone complex drives chaperone-mediated autophagy regulation in acute promyelocytic leukemia cell differentiation.

INTRODUCTION: Acute myeloid leukemia (AML) is a cancer of the hematopoietic system characterized by hyperproliferation of undifferentiated cells of the myeloid lineage. While most of AML therapies are focused towards tumor debulking, all-trans retinoic acid (ATRA) induces neutrophil differentiation in the AML subtype acute promyelocytic leukemia (APL). Macroautophagy has been extensively investigated in the context of various cancers and is often dysregulated in AML where it can have context-dependent pro- or anti-leukemogenic effects. On the contrary, the implications of chaperone-mediated autophagy (CMA) on the pathophysiology of diseases are still being explored and its role in AML has remains elusive. METHODS: We took advantages of human AML primary samples and databases to analyze CMA gene expression and activity. Furthermore, we used ATRA-sensitive (NB4) and -resistant (NB4-R1) cells to further dissect a potential function for CMA in ATRA-mediated neutrophil differentiation. NB4-R1 cells are unique in that they do respond to retinoic acid transcriptionally, but do not mature in response to retinoid signaling alone unless maturation is triggered by adding cAMP. RESULTS: Here, we report that CMA related mRNA transcripts are significantly higher expressed in immature hematopoietic cells as compared to neutrophils, contrasting the macroautophagy gene expression patterns. Accordingly, lysosomal degradation of an mCherry-KFERQ CMA reporter decreases during ATRA-induced differentiation of APL cells. On the other hand, using NB4-R1 cells we found that macroautophagy flux primed ATRA resistant NB4-R1 cells to differentiate upon ATRA treatment, but reduced association of lysosome-associated membrane protein type 2A (LAMP-2A) and heat shock protein family A (Hsp70) member 8 (HSPA8), which are necessary for complete neutrophil maturation. Accordingly, depletion of HSPA8 attenuated CMA activity and facilitated APL cell differentiation. In contrast, maintaining high CMA activity by ectopic expression of LAMP-2A impeded APL differentiation. CONCLUSION: Overall, our findings suggest that APL neutrophil differentiation requires CMA inactivation and that this pathway predominantly depends on HSPA8 and is possibly assisted by other co-chaperones.

A novel Nav1.8-FLPo driver mouse for intersectional genetics to uncover the functional significance of primary sensory neuron diversity.

The recent development of single-cell and single-nucleus RNA sequencing has highlighted the extraordinary diversity of dorsal root ganglia neurons. However, the few available genetic tools limit our understanding of the functional significance of this heterogeneity. We generated a new mouse line expressing the flippase recombinase from the scn10a locus. By crossing Nav1.8Ires-FLPo mice with the AdvillinCre and RC::FL-hM3Dq mouse lines in an intersectional genetics approach, we were able to obtain somatodendritic expression of hM3Dq-mCherry selectively in the Nav1.8 lineage. The bath application of clozapine N-oxide triggered strong calcium responses selectively in mCherry+ neurons. The intraplantar injection of CNO caused robust flinching, shaking, and biting responses accompanied by strong cFos activation in the ipsilateral lumbar spinal cord. The Nav1.8Ires-FLPo mouse model will be a valuable tool for extending our understanding of the in vivo functional specialization of neuronal subsets of the Nav1.8 lineage for which inducible Cre lines are available.

Improving nutritional status after allogeneic stem cell transplantation: results of phase 2 ALLONUT clinical trial.

Malnutrition increases the risk of non-relapse mortality after allogeneic stem cell transplantation (aHSCT). Here are the results of the ALLONUT clinical trial designed to improve the nutritional outcome of patients receiving aHSCT. ALLONUT is a prospective open label phase 2 clinical trial assessing the efficacy of a close tailored nutritional support and management with traditional and original solutions to improve patients nutritional status following aHSCT. Nutritional status evaluation was performed before transplantation, on Day 0, 30, 100 and one year after transplantation. The study involved 70 patients treated by aHSCT. 10% of patients were moderately or severely malnutrition at baseline and 26.9 were severely malnutrition at D30. Patients' nutritional status improved thanks to the cooking classes and the personalized outpatient nutrition program. At D100, 23% were still malnutrition, while only 10.8% were severely malnutrition one year after transplantation. The QLQ-C30 show that quality of life (QoL) decreased until D30, and improve to reach the pre-transplant level on D100 before exceeding it on D360. The study confirmed that a close, personalized nutritional program combining traditional and original measures can improve both nutritional status and QoL for patients suffering from moderate or severe malnutrition after aHCST.

The generation, activation, and polarization of monocyte-derived macrophages in human malignancies.

Macrophages are immune cells that originate from embryogenesis or from the differentiation of monocytes. They can adopt numerous phenotypes depending on their origin, tissue distribution and in response to different stimuli and tissue environment. Thus, in vivo, macrophages are endowed with a continuum of phenotypes that are rarely strictly pro-inflammatory or anti-inflammatory and exhibit a broad expression profile that sweeps over the whole polarization spectrum. Schematically, three main macrophage subpopulations coexist in human tissues: naïve macrophages also called M0, pro-inflammatory macrophages referred as M1 macrophages, and anti-inflammatory macrophages also known as M2 macrophages. Naïve macrophages display phagocytic functions, recognize pathogenic agents, and rapidly undergo polarization towards pro or anti-inflammatory macrophages to acquire their full panel of functions. Pro-inflammatory macrophages are widely involved in inflammatory response, during which they exert anti-microbial and anti-tumoral functions. By contrast, anti-inflammatory macrophages are implicated in the resolution of inflammation, the phagocytosis of cell debris and tissue reparation following injuries. Macrophages also play important deleterious or beneficial roles in the initiation and progression of different pathophysiological settings including solid and hematopoietic cancers. A better understanding of the molecular mechanisms involved in the generation, activation and polarization of macrophages is a prerequisite for the development of new therapeutic strategies to modulate macrophages functions in pathological situations.

Hepatitis E Virus Infection in Pediatric Oncology.

BACKGROUND: In the 2016 ESPGHAN recommendations on how to deal with hepatitis E virus infection in immunocompromised children, patients treated with chemotherapy were not specifically mentioned. OBSERVATIONS: Two teenagers treated with chemotherapy for acute leukemia and medulloblastoma, respectively, were diagnosed with hepatic cytolysis. After numerous investigations hepatitis E was found, limiting the good progress of the chemotherapy treatment. CONCLUSION: In the case of liver cytolysis in immunocompromised children treated with chemotherapy, hepatitis E virus infection has to be promptly diagnosed.

MCB-613 exploits a collateral sensitivity in drug resistant EGFR-mutant non-small cell lung cancer through covalent inhibition of KEAP1.

Targeted therapies have revolutionized cancer chemotherapy. Unfortunately, most patients develop multifocal resistance to these drugs within a matter of months. Here, we used a high-throughput phenotypic small molecule screen to identify MCB-613 as a compound that selectively targets EGFR-mutant, EGFR inhibitor-resistant non-small cell lung cancer (NSCLC) cells harboring diverse resistance mechanisms. Subsequent proteomic and functional genomic screens involving MCB-613 identified its target in this context to be KEAP1, revealing that this gene is selectively essential in the setting of EGFR inhibitor resistance. In-depth molecular characterization demonstrated that (1) MCB-613 binds KEAP1 covalently; (2) a single molecule of MCB-613 is capable of bridging two KEAP1 monomers together; and, (3) this modification interferes with the degradation of canonical KEAP1 substrates such as NRF2. Surprisingly, NRF2 knockout sensitizes cells to MCB-613, suggesting that the drug functions through modulation of an alternative KEAP1 substrate. Together, these findings advance MCB-613 as a new tool for exploiting the selective essentiality of KEAP1 in drug-resistant, EGFR-mutant NSCLC cells.

Nationwide Study of Continuous Deep Sedation Practices Among Pediatric Palliative Care Teams.

CONTEXT: Palliative sedation practices evolved in France when the Claeys-Leonetti law passed in 2016 authorized patient-requested continuous deep sedation (CDS) until death. Its implementation in the pediatric setting is less frequently encountered and can pose several clinical and ethical challenges for health care teams and families. OBJECTIVES: Our study aimed to describe CDS requests and practices of patients receiving specialized pediatric palliative care in France since its legalization in 2016. METHODS: We conducted a nationwide multicentric, descriptive, retrospective study using a self-report questionnaire completed by all Pediatric Palliative Care (PPC) Teams that were involved in a CDS case between January 2017 and December 2019. RESULTS: Six PPC teams had cared for six patients that had requested CDS, predominantly male adolescents/young adults diagnosed with a solid tumour. The refractory symptoms were diverse (pain, bleeding, and sensory loss) and always coupled with psycho-existential suffering. Each request was analyzed in multidisciplinary collegial meetings. Parental consent was always obtained regardless of age. Sedation typically required the use of multiple drugs including Midazolam (n = 5 cases), Chlorpromazine (n = 3), Ketamine (n = 2), and Propofol (n = 2). Despite close monitoring, achieving a satisfactory level of deep sedation was challenging and most patients unexpectedly awoke during CDS. Death occurred between 27 and 96 hours after induction. CONCLUSION: Managing patient-requested CDS in pediatrics is challenging due to its rarity, multi-factorial refractory symptoms and drug tolerance despite polytherapy. Few recommendations exist to guide CDS practice for pediatricians. Further studies investigating pediatric CDS practices across various cultural and legal settings, refractory symptom management and specific pharmacology are warranted.

Real-life challenges using personalized prognostic scoring systems in acute myeloid leukemia.

Personalized medicine is a challenge for patients with acute myeloid leukemia (AML). The identification of several genetic mutations in several AML trials led to the creation of a personalized prognostic scoring algorithm known as the Knowledge Bank (KB). In this study, we assessed the prognostic value of this algorithm on a cohort of 167 real life AML patients. We compared KB predicted outcomes to real-life outcomes. For patients younger than 60-year-old, OS was similar in favorable and intermediate ELN risk category. However, KB algorithm failed to predict OS for younger patients in the adverse ELN risk category and for patients older than 60 years old in the favorable ELN risk category. These discrepancies may be explained by the emergence of several new therapeutic options as well as the improvement of allogeneic stem cell transplantation (aHSCT) outcomes and supportive cares. Personalized medicine is a major challenge and predictions models are powerful tools to predict patient's outcome. However, the addition of new therapeutic options in the field of AML requires a prospective validation of these scoring systems to include recent therapeutic innovations.

Paediatric palliative care: why transfuse?

Should indication for transfusion in paediatric palliative care be based on the child's perspective rather than the biological results? An 8-year-old boy presenting a relapse of a stage IV neuroblastoma received regular blood transfusions. A severe exophtalmia led the doctors to question the transfusion strategy. Over 7.5 months, the child received 56 red blood cell units and 31 platelet units. He was hospitalised 50 times. Indication for blood test and transfusion may be regularly and collegially reassessed. Transfusion needs in a palliative strategy can be as high as in a curative strategy. Practices, benefits but also ethical and public health dimensions should be more studied.

Expert survey on coverage and characteristics of pediatric palliative care in Europe - a focus on home care.

BACKGROUND: For children with life-limiting conditions home care is a key component of pediatric palliative care. However, poor information is available on service coverage and in particular on country-specific pediatric palliative home care characteristics. The aim of the study was therefore to describe the association between pediatric palliative care coverage and national activities and obtain detailed information on the pediatric palliative home care structure in different European countries. METHODS: Online survey with in-country experts from N = 33 European countries. RESULTS: Pediatric palliative home care (65.6%) represented the most pediatric palliative care units (15.6%) and the least common services. National documents constituted the most widespread national pediatric palliative care activity (59.4%) and were associated with available services. Pediatric palliative home care could be mostly accessed as a service free of charge to families (95.2%) from the time of a child's diagnosis (85.7%). In most countries, oncological and non-oncological patients were cared for in pediatric palliative home care. Only a minority of home care teams covered home-ventilated children. Pediatric palliative home care usually comprised medical care (81.0%), care coordination (71.4%), nursing care (75.0%) and social support (57.1%). Most countries had at least two professional groups working in home care teams (81.0%), mostly physicians and nurses. In many countries, pediatric palliative home care was not available in all regions and did not offer a 24 h-outreach service. CONCLUSIONS: Pediatric palliative care provision in Europe is heterogeneous. Further work on country-specific structures is needed.

[Feelings of cancer patients in exclusive palliative care: Towards a general practitioner, oncologist pairing?] / Ressenti des patients atteints de cancer en soins palliatifs exclusifs: vers un binôme médecin généraliste, cancérologue?

INTRODUCTION: In palliative care, cancer patients' thoughts about support given by their general practitioner are poorly described in the literature. General practitioners are involved in the management of cancer patients in palliative care, but when contact with the oncologist become less frequent, the place of the patient's different doctors becomes difficult to define. The objective of our work is to analyze the patient's perception of the place and role of the general practitioner. METHODS: Qualitative study by individual semi-directed interviews, with voluntary patients with solid cancer in palliative care. Patients were selected by palliative care physicians. A thematic analysis was performed on the basis of the patients' verbatim transcripts. RESULTS: Seventeen patients were interviewed and four main themes were highlighted: a perception of abandonment, a resignation to call the general practitioner, an omnipresence of the oncologist who seems not to leave the place to the general practitioner and a search for global support. The general practitioner did not appear to be empathetic nor supportive enough and was not available enough. DISCUSSION: Patients are looking for empathy and for their doctors to listen. Our work shows a certain disappointment of the patients regarding the place and role of their general practitioner. This disappointment reflects the insufficient coordination between hospital and community care setting. While the early integration of palliative care is becoming a standard of care, the patients' testimony commits us to improve the articulation between the oncologist and the general practitioner.

Reprogramming monocyte-derived macrophages through caspase inhibition.

Macrophages are widely distributed innate immune cells that play an indispensable role in a variety of physiologic and pathologic processes, including organ development, host defense, acute and chronic inflammation, solid and hematopoietic cancers. Beyond their inextricable role as conveyors of programmed cell death, we have previously highlighted that caspases exert non-apoptotic functions, especially during the differentiation of monocyte-derived cells in response to CSF-1. Here, we found that non-canonic cleavages of caspases, reflecting their activation, are maintained during IL-4-induced monocyte-derived macrophages polarization. Moreover, Emricasan, a pan-caspase inhibitor that demonstrated promising preclinical activity in various diseases and safely entered clinical testing for the treatment of liver failure, prevents the generation and the anti-inflammatory polarization of monocyte-derived macrophages ex vivo. Interestingly, caspase inhibition also triggered the reprogramming of monocyte-derived cells evidenced by RNA sequencing. Taken together, our findings position Emricasan as a potential alternative to current therapies for reprogramming macrophages in diseases driven by monocyte-derived macrophages.

Ultrasound-assisted one-pot three-component synthesis of new isoxazolines bearing sulfonamides and their evaluation against hematological malignancies.

In the present study, following a one-pot two-step protocol, we have synthesized novel sulfonamides-isoxazolines hybrids (3a-r) via a highly regioselective 1,3-dipolar cycloaddition. The present methodology capitalized on trichloroisocyanuric acid (TCCA) as a safe and ecological oxidant and chlorinating agent for the in-situ conversion of aldehydes to nitrile oxides in the presence of hydroxylamine hydrochloride, under ultrasound activation. These nitrile oxides could be engaged in 1,3-dipolar cycloaddition reactions with various alkene to afford the targeted sulfonamides-isoxazolines hybrids (3a-r). The latter were assessed for their antineoplastic activity against model leukemia cell lines (Chronic Myeloid Leukemia, K562 and Promyelocytic Leukemia, HL-60).

Dual Covalent Inhibition of PKM and IMPDH Targets Metabolism in Cutaneous Metastatic Melanoma.

Overcoming acquired drug resistance is a primary challenge in cancer treatment. Notably, more than 50% of patients with BRAFV600E cutaneous metastatic melanoma (CMM) eventually develop resistance to BRAF inhibitors. Resistant cells undergo metabolic reprogramming that profoundly influences therapeutic response and promotes tumor progression. Uncovering metabolic vulnerabilities could help suppress CMM tumor growth and overcome drug resistance. Here we identified a drug, HA344, that concomitantly targets two distinct metabolic hubs in cancer cells. HA344 inhibited the final and rate-limiting step of glycolysis through its covalent binding to the pyruvate kinase M2 (PKM2) enzyme, and it concurrently blocked the activity of inosine monophosphate dehydrogenase, the rate-limiting enzyme of de novo guanylate synthesis. As a consequence, HA344 efficiently targeted vemurafenib-sensitive and vemurafenib-resistant CMM cells and impaired CMM xenograft tumor growth in mice. In addition, HA344 acted synergistically with BRAF inhibitors on CMM cell lines in vitro. Thus, the mechanism of action of HA344 provides potential therapeutic avenues for patients with CMM and a broad range of different cancers. SIGNIFICANCE: Glycolytic and purine synthesis pathways are often deregulated in therapy-resistant tumors and can be targeted by the covalent inhibitor described in this study, suggesting its broad application for overcoming resistance in cancer.

Retraction Note: LAMP2 expression dictates azacytidine response and prognosis in MDS/AML.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Clonal selection in therapy-related myelodysplastic syndromes and acute myeloid leukemia under azacitidine treatment.

INTRODUCTION: Therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) are defined as complications of previous cytotoxic therapy. Azacitidine (AZA), a hypomethylating agent, has showed activity in t-MDS/AML. OBJECTIVES: We evaluated the clonal dynamics of AZA-treated t-MDS/AML. METHODS: We collected bone marrow samples, at diagnosis and during treatment, from AZA-treated t-MDS/AML patients. NGS on 19 myeloid genes was performed, and candidate mutations with a variant allele frequency >5% were selected. RESULTS: Seven t-AML and 12 t-MDS were included with median age of 71 (56-82) years old, median number of AZA cycles of 6 (1-15), and median overall survival (OS) of 14 (3-29) months. We observed correlation between AZA response and clonal selection. Decrease of TP53-mutated clone was correlated with response to AZA, confirming AZA efficacy in this subgroup. In some patients, emergence of mutations was correlated with progression or relapse without impact on OS. Clones with mutations in genes for DNA methylation regulation frequently occurred with other mutations and remained stable during AZA treatment, independent of AZA response. CONCLUSION: We confirmed that the molecular complexity of t-MNs and that the follow-up of clonal selection during AZA treatment could be useful to define treatment combination.

Acadesine Circumvents Azacitidine Resistance in Myelodysplastic Syndrome and Acute Myeloid Leukemia.

Myelodysplastic syndrome (MDS) defines a group of heterogeneous hematologic malignancies that often progresses to acute myeloid leukemia (AML). The leading treatment for high-risk MDS patients is azacitidine (Aza, Vidaza®), but a significant proportion of patients are refractory and all patients eventually relapse after an undefined time period. Therefore, new therapies for MDS are urgently needed. We present here evidence that acadesine (Aca, Acadra®), a nucleoside analog exerts potent anti-leukemic effects in both Aza-sensitive (OCI-M2S) and resistant (OCI-M2R) MDS/AML cell lines in vitro. Aca also exerts potent anti-leukemic effect on bone marrow cells from MDS/AML patients ex-vivo. The effect of Aca on MDS/AML cell line proliferation does not rely on apoptosis induction. It is also noteworthy that Aca is efficient to kill MDS cells in a co-culture model with human medullary stromal cell lines, that mimics better the interaction occurring in the bone marrow. These initial findings led us to initiate a phase I/II clinical trial using Acadra® in 12 Aza refractory MDS/AML patients. Despite a very good response in one out 4 patients, we stopped this trial because the highest Aca dose (210 mg/kg) caused serious renal side effects in several patients. In conclusion, the side effects of high Aca doses preclude its use in patients with strong comorbidities.