LAMP2 expression dictates azacytidine response and prognosis in MDS/AML

Effect of lncRNA XIST on acute myeloid leukemia cells via miR-142-5p-PFKP axis

Acute myeloid leukemia (AML) is the common blood cancer in hematopoietic system-related diseases and has a poor prognosis. Studies have shown that long non-coding RNAs (lncRNAs) are closely related to the pathogenesis of a variety of diseases, including AML. However, the specific molecular mechanism remains unclear. Hence, the objective of this study was to investigate the effect and mechanism of lncRNA X inactive specific transcript (lncRNA XIST) on AML. To achieve our objective, some tests were performed. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression of lncRNA XIST, miR-142-5p and the platelet isoform of phosphofructokinase (PFKP). The targeting relationship between miR-142-5p and lncRNA XIST and PFKP was verified by Pearson correlation analysis, dual-luciferase reporter assay, and pull-down assay. Functional experiments were used to analyze the effect and mechanism of action of knocking down lncRNA XIST on THP-1 and U937 cells. Compared with bone marrow cells, lncRNA XIST and PFKP expression levels were up-regulated and miR-142-5p expression levels were down-regulated in AML. Further analysis revealed that lncRNA XIST targeted and bound to miR-142-5p, and PFKP was a target gene of miR-142-5p. Knockdown of lncRNA XIST significantly promoted miR-142-5p expression to down-regulate PFKP in THP-1 and U937 cells, while the cell proliferation, cell viability, and cell cycle arrest were inhibited and apoptosis was increased. Knockdown of miR-142-5p reversed the functional impact of lncRNA XIST knockdown on AML cells. In conclusion, down-regulation of lncRNA XIST can affect the progression of AML by regulating miR-142-5p.

LncRNA OBFC2A modulated benzene metabolites-induced autophagy and apoptosis by interacting with LAMP2

Exposure to benzene results in peripheral blood cell reduction, aplastic anemia, and leukemia. We previously observed that the lncRNA OBFC2A was upregulated significantly in benzene-exposed workers and correlated with reduced blood cell counts. However, the role of lncRNA OBFC2A in benzene hematotoxicity remains unclear. In this study, we discovered that lncRNA OBFC2A was regulated by oxidative stress and played roles in cell autophagy and apoptosis caused by the benzene metabolite 1,4-Benzoquinone (1,4-BQ) in vitro. Mechanistically, protein chip, RNA pull-down and FISH colocalization uncovered that lncRNA OBFC2A directly bound to LAMP2, a regulator of chaperone-mediated autophagy (CMA), and upregulated its expression in 1,4-BQ-treated cells. LncRNA OBFC2A knockdown alleviated LAMP2 overexpression caused by 1,4-BQ, which confirmed their regulatory relationship. In conclusion, we demonstrate that lncRNA OBFC2A mediates 1,4-BQ-induced apoptosis and autophagy by interacting with LAMP2. LncRNA OBFC2A could serve as a biomarker for hematotoxicity caused by benzene.

Epigenetic and post-translational modifications in autophagy: biological functions and therapeutic targets

Autophagy is a conserved lysosomal degradation pathway where cellular components are dynamically degraded and re-processed to maintain physical homeostasis. However, the physiological effect of autophagy appears to be multifaced. On the one hand, autophagy functions as a cytoprotective mechanism, protecting against multiple diseases, especially tumor, cardiovascular disorders, and neurodegenerative and infectious disease. Conversely, autophagy may also play a detrimental role via pro-survival effects on cancer cells or cell-killing effects on normal body cells. During disorder onset and progression, the expression levels of autophagy-related regulators and proteins encoded by autophagy-related genes (ATGs) are abnormally regulated, giving rise to imbalanced autophagy flux. However, the detailed mechanisms and molecular events of this process are quite complex. Epigenetic, including DNA methylation, histone modifications and miRNAs, and post-translational modifications, including ubiquitination, phosphorylation and acetylation, precisely manipulate gene expression and protein function, and are strongly correlated with the occurrence and development of multiple diseases. There is substantial evidence that autophagy-relevant regulators and machineries are subjected to epigenetic and post-translational modulation, resulting in alterations in autophagy levels, which subsequently induces disease or affects the therapeutic effectiveness to agents. In this review, we focus on the regulatory mechanisms mediated by epigenetic and post-translational modifications in disease-related autophagy to unveil potential therapeutic targets. In addition, the effect of autophagy on the therapeutic effectiveness of epigenetic drugs or drugs targeting post-translational modification have also been discussed, providing insights into the combination with autophagy activators or inhibitors in the treatment of clinical diseases.

Autophagy and Its Lineage-Specific Roles in the Hematopoietic System

Autophagy is a dynamic process that regulates the selective and nonselective degradation of cytoplasmic components, such as damaged organelles and protein aggregates inside lysosomes to maintain tissue homeostasis. Different types of autophagy including macroautophagy, microautophagy, and chaperon-mediated autophagy (CMA) have been implicated in a variety of pathological conditions, such as cancer, aging, neurodegeneration, and developmental disorders. Furthermore, the molecular mechanism and biological functions of autophagy have been extensively studied in vertebrate hematopoiesis and human blood malignancies. In recent years, the hematopoietic lineage-specific roles of different autophagy-related (ATG) genes have gained more attention. The evolution of gene-editing technology and the easy access nature of hematopoietic stem cells (HSCs), hematopoietic progenitors, and precursor cells have facilitated the autophagy research to better understand how ATG genes function in the hematopoietic system. Taking advantage of the gene-editing platform, this review has summarized the roles of different ATGs at the hematopoietic cell level, their dysregulation, and pathological consequences throughout hematopoiesis.

The role of autophagy in acute myeloid leukemia development

INTRODUCTION

Autophagy is a highly conservative self-degradative process. It aims at elimination-impaired proteins and cellular organelles. Previous research confirmed the autophagy role in cancer pathogenesis.

AREAS COVERED

This article discusses the role of autophagy in the development of AML. Autophagy seems to be a 'double-sword' mechanism, hence, either its suppression or induction could promote neoplasm growth. This mechanism could also be the aim of the 'molecular targeted therapy.' Chemo- and radiotherapy induce cellular stress in neoplasm cells with subsequent autophagy suppression. Simultaneously, it is claimed that the autophagy suppression increases chemosensitivity 'in neoplastic cells. Some agents, like bortezomib, in turn could promote autophagy process, e.g. in AML (acute myeloid leukemia). However, currently there are not many studies focusing on the role of autophagy in patients suffering for AML. In this review, we summarize the research done so far on the role of autophagy in the development of AML.

EXPERT OPINION

The analysis of autophagy genes expression profiling in AML could be a relevant factor in the diagnostic process and treatment 'individualization.' Autophagy modulation seems to be a relevant target in the oncological therapy - it could limit disease progression and increase the effectiveness of treatment.

Targeting Protein Degradation Pathways in Tumors: Focusing on their Role in Hematological Malignancies

Cells must maintain their proteome homeostasis by balancing protein synthesis and degradation. This is facilitated by evolutionarily-conserved processes, including the unfolded protein response and the proteasome-based system of protein clearance, autophagy, and chaperone-mediated autophagy. In some hematological malignancies, including acute myeloid leukemia, misfolding or aggregation of the wild-type p53 tumor-suppressor renders cells unable to undergo apoptosis, even with an intact p53 DNA sequence. Moreover, blocking the proteasome pathway triggers lymphoma cell apoptosis. Extensive studies have led to the development of proteasome inhibitors, which have advanced into drugs (such as bortezomib) used in the treatment of certain hematological tumors, including multiple myeloma. New therapeutic options have been studied making use of the so-called proteolysis-targeting chimeras (PROTACs), that bind desired proteins with a linker that connects them to an E3 ubiquitin ligase, resulting in proteasomal-targeted degradation. This review examines the mechanisms of protein degradation in the cells of the hematopoietic system, explains the role of dysfunctional protein degradation in the pathogenesis of hematological malignancies, and discusses the current and future advances of therapies targeting these pathways, based on an extensive search of the articles and conference proceedings from 2005 to April 2022.

Predicting outcome in higher-risk myelodysplastic syndrome patients treated with azacitidine

5-Azacitidine (5-AZA) is widely used for the treatment of higher-risk myelodysplastic syndromes. However, response and survival rates vary considerably, while indicated treatment duration remains undefined. For these reasons, factors determining response and survival are of major importance. Clinical, morphological, flow cytometry, cytogenetic and molecular factors are discussed in this review. Biomarkers predictive of response and prognosis, as well as their link to the mode of action of 5-AZA are also addressed, shifting the focus from clinical practice to investigational research. Their use could further improve prognostic classification of 5-AZA treated higher-risk myelodysplastic syndromes in the near future.

Inhibition of chaperone‑mediated autophagy reduces tumor growth and metastasis and promotes drug sensitivity in colorectal cancer

Chaperone-mediated autophagy (CMA) is a selective type of autophagy whereby a specific subset of intracellular proteins is targeted to the lysosome for degradation. The present study investigated the mechanisms underlying the response and resistance to 5-fluorouracil (5-FU) in colorectal cancer (CRC) cell lines. In engineered 5-FU-resistant CRC cell lines, a significant elevation of lysosome-associated membrane protein 2A (LAMP2A), which is the key molecule in the CMA pathway, was identified. High expression of LAMP2A was found to be responsible for 5-FU resistance and to enhance PLD2 expression through the activation of NF-κB pathway. Accordingly, loss or gain of function of LAMP2A in 5-FU-resistant CRC cells rendered them sensitive or resistant to 5-FU, respectively. Taken together, the results of the present study suggested that chemoresistance in patients with CRC may be mediated by enhancing CMA. Thus, CMA is a promising predictor of chemosensitivity to 5-FU treatment and anti-CMA therapy may be a novel therapeutic option for patients with CRC.

Long noncoding RNA LINC00467 facilitates the progression of acute myeloid leukemia by targeting the miR-339/SKI pathway

A growing body of evidence indicates that long non-coding RNA (lncRNA) is involved in the development and progression of many diseases. It has been reported that lncRNA LINC00467 is disregulated in multiple tumors, while its role in acute myeloid leukemia (AML) is still unknown. Here, we find that LINC00467 expression is significantly increased in AML specimens and cell lines. Further investigations show that knockdown of LINC00467 inhibits the malignant phenotypes of AML cells. Consistently, LINC00467 knockdown slows AML progression in immunodeficient mice. Interestingly, microRNA-339 (miR-339) is upregulated and its target gene SKI, an oncogene, is downregulated in AML cells after LINC00467 knockdown. More importantly, inhibition of miR-339 can largely abolish the effect of LINC00467 knockdown on AML cells. Collectively, our data demonstrate that LINC00467 plays an important role in the pathogenesis of AML by targeting the miR-339/SKI pathway, which provides a new sight for the subsequent treatment of AML.

The role of autophagy in targeted therapy for acute myeloid leukemia

Although molecular targeted therapies have recently displayed therapeutic effects in acute myeloid leukemia (AML), limited response and acquired resistance remain common problems. Numerous studies have associated autophagy, an essential degradation process involved in the cellular response to stress, with the development and therapeutic response of cancers including AML. Thus, we review studies on the role of autophagy in AML development and summarize the linkage between autophagy and several recurrent genetic abnormalities in AML, highlighting the potential of capitalizing on autophagy modulation in targeted therapy for AML.Abbreviations: AML: acute myeloid leukemia; AMPK: AMP-activated protein kinase; APL: acute promyelocytic leukemia; ATG: autophagy related; ATM: ATM serine/threonine kinase; ATO: arsenic trioxide; ATRA: all trans retinoic acid; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; BET proteins, bromodomain and extra-terminal domain family; CMA: chaperone-mediated autophagy; CQ: chloroquine; DNMT, DNA methyltransferase; DOT1L: DOT1 like histone lysine methyltransferase; FLT3: fms related receptor tyrosine kinase 3; FIS1: fission, mitochondrial 1; HCQ: hydroxychloroquine; HSC: hematopoietic stem cell; IDH: isocitrate dehydrogenase; ITD: internal tandem duplication; KMT2A/MLL: lysine methyltransferase 2A; LSC: leukemia stem cell; MDS: myelodysplastic syndromes; MTORC1: mechanistic target of rapamycin kinase complex 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; NPM1: nucleophosmin 1; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PML: PML nuclear body scaffold; ROS: reactive oxygen species; RB1CC1/FIP200: RB1 inducible coiled-coil 1; SAHA: vorinostat; SQSTM1: sequestosome 1; TET2: tet methylcytosine dioxygenase 2; TKD: tyrosine kinase domain; TKI: tyrosine kinase inhibitor; TP53/p53: tumor protein p53; ULK1: unc-51 like autophagy activating kinase 1; VPA: valproic acid; WDFY3/ALFY: WD repeat and FYVE domain containing 3.

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.

Systematic Analysis of Autophagy-Related Signature Uncovers Prognostic Predictor for Acute Myeloid Leukemia

Autophagy, a highly conserved cellular protein degradation process, has been involved in acute myeloid leukemia (AML). The present study aims to establish a novel, autophagy-related prognostic signature for prediction of AML prognosis. Differentially expressed autophagy-related genes in AML and healthy samples were screened using GSE1159. Univariate Cox regression analysis was applied to determine survival-associated autophagy-related genes in The Cancer Genome Atlas (TCGA) AML cohort. Lasso regression was performed to develop multiple-gene prognostic signatures. A novel six-gene signature (including CASP3, CHAF1B, KLHL24, OPTN, VEGFA, and VPS37C) DC was established for AML prognosis prediction. The Kaplan-Meier survival analysis revealed that patients in the high-risk score group had poorer overall survival (OS). The receiver operating characteristic (ROC) curve validated its good performance in survival prediction in TCGA AML cohort, and the area under the curve value was 0.817. Moreover, our signature could independently predict OS. A nomogram was constructed, including the six-gene signature and other clinical parameters, and predictive efficiency was confirmed using the ROC curve and calibration curve. Furthermore, gene set enrichment analyses identified several tumor-associated pathways that may contribute to explain the potential molecular mechanisms of our signature. Overall, we developed a new autophagy-associated gene signature and nomogram to predict OS of AML patients, which may help in clinical decision-making for AML treatment.

Dysregulated FAM215A Stimulates LAMP2 Expression to Confer Drug-Resistant and Malignant in Human Liver Cancer

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human malignancies worldwide. Long non-coding (lnc) RNAs regulate complex cellular functions, such as cell growth, differentiation, metabolism, and metastasis. Although deregulation of lncRNA expression has been detected in HCC, many of the hepato-carcinogenesis-associated lncRNAs remain yet unidentified. Here, we aimed to investigate the involvement of a specific HCC-dysregulated lncRNA, FAM215A, and characterize its molecular regulation mechanism. We show for the first time that FAM215A is overexpressed in HCC, and its expression level correlates with tumor size, vascular invasion, and pathology stage. Overexpression of FAM215A accelerates cell proliferation and metastasis in HCC cells. According to Gene Expression Omnibus Dataset analysis, FAM215A is induced in doxorubicin (DOX)-resistant HCC cells. Overexpression of FAM215A increases DOX resistance in two HCC cell lines, and this is associated with enhanced expression of lysosome-associated membrane protein 2 (LAMP2). FAM215A interacts with LAMP2 to protect it from ubiquitination. Together, our results show that the lncRNA, FAM215A, is highly expressed in HCC, where it interacts with and stabilizes LAMP2 to increase tumor progression while decreasing doxorubicin sensitivity.

Genome-wide identification of FHL1 as a powerful prognostic candidate and potential therapeutic target in acute myeloid leukaemia

Background

Acute myeloid leukaemia (AML) is a malignant haematological tumour with high heterogeneity and mortality. A reliable prognostic assessment is critical for treatment strategies. However, the current prognostic evaluation system of AML is insufficient.

Methods

Genome-wide univariate Cox regression analysis was performed on three independent AML datasets to screen for the prognostic-related genes. Kaplan–Meier survival analysis was employed to verify the efficacy of FHL1 in evaluating overall survival in 1298 de novo AML patients, 648 non-acute promyelocytic leukaemia AML patients and 407 cytogenetically normal AML patients; the data for some of these patients were also used for EFS and RFS validation. Multivariate Cox regression was performed to validate FHL1 as an independent prognostic indicator. WGCNA, GSEA, and gene correlation analysis were applied to explore the mechanism of FHL1 in AML. The synergistic cytocidal effect of FHL1 knockdown was verified in in vitro experiments.

Findings

Comprehensive genome-wide analyses and large-sample validation showed that FHL1 is a powerful prognostic candidate for overall survival, event-free survival, and relapse-free survival in AML and is independent of prognosis-related clinical factors and genetic abnormalities. The molecular mechanism may occur through regulation of FHL1 in leukaemia stem cells, tumour-associated signalling pathways, and transmembrane transport of chemotherapeutic drugs. FHL1-targeted intervention enhances the sensitivity of AML cells to cytarabine.

Interpretation

FHL1 may serve as an evaluation factor for clinical strategy selection, and its targeted intervention may be beneficial for chemotherapy in AML patients.

Chaperone-mediated autophagy in cancer: Advances from bench to bedside

Chaperone-mediated autophagy (CMA), a selective form of autophagy, where cellular proteins with KFERQ-like motif are targeted to the lysosome for degradation, is necessary to maintain cellular homeostasis. The role of CMA in neurodegenerative diseases has been extensively studied in the past decades, with defects in the pathway being strongly associated with disease. Recently, accumulating evidence has demonstrated a consistent increase in basal CMA activity in a wide array of cancer cell lines and human tumor biopsies, suggesting a potential link between CMA and cancer. On the other hand, an anti-oncogenic role for CMA under physiological conditions in non-transformed cells is also proposed despite the pro-tumorigenic function of CMA in cancer cells. The growing number of connections between CMA and cancers has generated interest in modulating CMA activity for therapeutic purposes. Here, we describe recent advances in the understanding of the molecular regulation of CMA, and discuss the evidence in support of the contribution of CMA dysfunction to cancers.

PHLPP Sensitizes Multiple Myeloma Cells to Bortezomib Through Regulating LAMP2

Introduction

Treatment of bortezomib (BTZ) improves the clinical outcomes of patients with multiple myeloma (MM). However, primary resistance and acquired resistance to BTZ frequently develop in patients with MM. PH domain leucine-rich repeat protein phosphatase (PHLPP) plays an important role in chemoresistance in a number of cancers. However, the role of PHLPP on MM remains unclear. In this study, we investigated the role of PHLPP in BTZ-resistant MM cells.

Methods

BrdU assays, immunoprecipitation, flow cytometry analyses, and immunofluorescence assays were performed.

Results

PHLPP and lysosome-associated membrane protein 2 (LAMP2) levels were downregulated in BTZ-resistant MM cells compared with BTZ-sensitive MM cells, accompanied by inactivation of autophagy pathway evaluated by a reduction in Beclin1, Atg5 and LC3B and increase in p62. Gain- and loss-of-function experiments revealed that PHLPP partially re-sensitized MM cells to BTZ. In addition, PHLPP overexpression increased whereas PHLPP knockdown reduced LAMP2 expression, subsequently regulating the autophagy pathway in MM cells. Further findings demonstrated that LAMP2 knockdown reversed PHLPP-mediated cell apoptosis and autophagy activation in MM cells.

Conclusion

This study demonstrated that PHLPP is a potential strategy for overcoming BTZ resistance in patients with MM.

Pros and Cons of Chaperone-Mediated Autophagy in Cancer Biology

Autophagy contributes to cellular quality control and energetics through lysosomal breakdown and recycling of essential cellular components. Chaperone-mediated autophagy (CMA) adds to these autophagic functions the ability to timely and selectively degrade single tagged proteins to terminate their cellular function and, in this way, participate in the regulation of multiple cellular processes. Many cancer cells upregulate CMA for protumorigenic and prosurvival purposes. However, growing evidence supports a physiological role for CMA in limiting malignant transformation. Understanding the mechanisms behind this functional switch of CMA from antioncogenic to pro-oncogenic is fundamental for targeting CMA in cancer treatment. We summarize current understanding of CMA functions in cancer biology and discuss the basis for its context-dependent dual role in oncogenesis.

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.

Chaperone-Mediated Autophagy and Its Emerging Role in Hematological Malignancies

Chaperone-mediated autophagy (CMA) ensures the selective degradation of cellular proteins endowed with a KFERQ-like motif by lysosomes. It is estimated that 30% of all cellular proteins can be directed to the lysosome for CMA degradation, but only a few substrates have been formally identified so far. Mechanistically, the KFERQ-like motifs present in substrate proteins are recognized by the molecular chaperone Hsc70c (Heat shock cognate 71 kDa protein cytosolic), also known as HSPA8, and directed to LAMP2A, which acts as the CMA receptor at the lysosomal surface. Following linearization, the protein substrate is next transported to the lumen of the lysosomes, where it is degraded by resident proteases, mainly cathepsins and eventually recycled to sustain cellular homeostasis. CMA is induced by different stress conditions, including energy deprivation that also activates macro-autophagy (MA), that may make it difficult to decipher the relative impact of both pathways on cellular homeostasis. Besides common inducing triggers, CMA and MA might be induced as compensatory mechanisms when either mechanism is altered, as it is the often the case in different pathological settings. Therefore, CMA activation can compensate for alterations of MA and vice versa. In this context, these compensatory mechanisms, when occurring, may be targeted for therapeutic purposes. Both processes have received particular attention from scientists and clinicians, since modulation of MA and CMA may have a profound impact on cellular proteostasis, metabolism, death, differentiation, and survival and, as such, could be targeted for therapeutic intervention in degenerative and immune diseases, as well as in cancer, including hematopoietic malignancies. The role of MA in cancer initiation and progression is now well established, but whether and how CMA is involved in tumorigenesis has been only sparsely explored. In the present review, we encompass the description of the mechanisms involved in CMA, its function in the physiology and pathogenesis of hematopoietic cells, its emerging role in cancer initiation and development, and, finally, the potential therapeutic opportunity to target CMA or CMA-mediated compensatory mechanisms in hematological malignancies.

Azacitidine resistance caused by LAMP2 deficiency: a therapeutic window for the use of autophagy inhibitors in MDS/AML patients?

Chaperone-mediated autophagy (CMA) is a selective form of autophagy that allows the elimination and recycling of cytosolic proteins endowed with a KFERQ-like motif into the lysosome. During this process, the proteins to be degraded are recognized by cellular chaperones such as HSC70 and presented to the CMA receptor LAMP2A, which then translocate them into lysosomes for degradation. In this punctum, we discuss the mechanisms underlying the response and resistance to Azacitidine (Aza) in MDS/AML cell lines and bone marrow CD34+ blasts from MDS/AML patients. We show that treatment of MDS/AML cell lines and bone marrow samples from MDS/AML patients with Aza triggers loss of LAMP2 expression leading to CMA defects. LAMP2 deficiency is responsible for CMA defects, Aza resistance and hypersensitivity to lysosome and autophagy inhibitors. Low levels of LAMP2 expression in CD34+ blasts from MDS/AML patients correlate with an absence of response to Aza and are associated to a pejorative overall survival. We propose that CD34+/LAMP2Low patients at diagnosis or who become CD34+/LAMP2Low during the course of treatment with Aza could receive an autophagy inhibitor available in the clinic.

Therapeutic Modulation of Autophagy in Leukaemia and Lymphoma

Haematopoiesis is a tightly orchestrated process where a pool of hematopoietic stem and progenitor cells (HSPCs) with high self-renewal potential can give rise to both lymphoid and myeloid lineages. The HSPCs pool is reduced with ageing resulting in few HSPC clones maintaining haematopoiesis thereby reducing blood cell diversity, a phenomenon called clonal haematopoiesis. Clonal expansion of HSPCs carrying specific genetic mutations leads to increased risk for haematological malignancies. Therefore, it comes as no surprise that hematopoietic tumours develop in higher frequency in elderly people. Unfortunately, elderly patients with leukaemia or lymphoma still have an unsatisfactory prognosis compared to younger ones highlighting the need to develop more efficient therapies for this group of patients. Growing evidence indicates that macroautophagy (hereafter referred to as autophagy) is essential for health and longevity. This review is focusing on the role of autophagy in normal haematopoiesis as well as in leukaemia and lymphoma development. Attenuated autophagy may support early hematopoietic neoplasia whereas activation of autophagy in later stages of tumour development and in response to a variety of therapies rather triggers a pro-tumoral response. Novel insights into the role of autophagy in haematopoiesis will be discussed in light of designing new autophagy modulating therapies in hematopoietic cancers.