scholarly journals Inhibition of PINK1-Dependent Mitochondrial Quality Control Pathways Induces Senescence of Acute Myeloid Leukemia Stem Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2225-2225
Author(s):  
Dhanoop Manikoth Ayyathan ◽  
David Sharon ◽  
Severine Cathelin ◽  
Steven M Chan
Keyword(s):  
Quality Control ◽  
Cell Fate ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Mitochondrial Quality Control ◽  
Telomere Shortening ◽  
Cycle Arrest ◽  
Colony Forming Capacity ◽  
Acute Myeloid

Abstract Current treatments for acute myeloid leukemia (AML) are often ineffective in eliminating leukemic stem cells (LSCs), which perpetuate the disease. Novel therapies that target LSCs have the potential to improve clinical outcomes. An important step towards achieving this goal is identifying the fundamental processes that regulate cell fate decisions in LSCs. Perturbation of these processes may impair LSC activity and form the basis of novel therapies. Here, we investigated the role of mitochondrial quality control in the regulation of LSCs by inhibiting PTEN-induced kinase 1 (PINK1). PINK1 is a serine/threonine kinase that serves as a critical sensor of mitochondrial damage and is at the apex of multiple quality control pathways that maintain mitochondrial homeostasis. Damage to mitochondria results in activation of PINK1 on the outer mitochondrial membrane, which in turn triggers mitochondrial fission and mitophagy. We first determined if the overall quality of the mitochondrial pool differs between LSCs and their more differentiated progenies (henceforth termed "non-LSCs") in two human AML cultures known as OCI-AML-8227 and OCI-AML-21. In both cultures, LSCs assayed by xenotransplantation are found only in the CD34 +CD38 -fraction and not in the CD34 +CD38 + and CD34 - fractions. We monitored the turnover rate of the mitochondrial pool in the different fractions by expressing MitoTimer, a mitochondria-targeted fluorescent protein that matures from green to red fluorescence over 48 hours. A high ratio of green to red fluorescence is indicative of active mitochondrial protein turnover and high overall mitochondrial quality. In both cell lines, the fluorescence ratio was highest in the CD34 +CD38 - fraction compared with the other fractions, suggesting that LSCs maintain a higher quality pool of mitochondria than non-LSCs. Based on the above findings, we hypothesized that PINK1-dependent mitochondrial quality control mechanisms are involved in the regulation of LSC fate. To test this hypothesis, we silenced the expression of PINK1 in OCI-AML-8227 cells using lentiviral vectors expressing validated shRNAs under a doxycycline-inducible promoter. Depletion of PINK1 shifted the MitoTimer fluorescence from green to red, reduced oxygen consumption rate, and disrupted mitochondrial ultrastructure in all cell fractions, consistent with a reduction in mitochondrial quality. Unexpectedly, PINK1 downregulation resulted in a block in differentiation and cell cycle arrest at G1/G0 phase in CD34 +CD38 - cells. Re-expression of PINK1 was unable to reverse the cell cycle arrest, suggestive of a state of cellular senescence. Indeed, we observed other hallmarks of senescence including an increase in p21 WAF1 and p16 INK4a expression and SA-β-gal activity. To determine the mechanism by which PINK1 depletion causes senescence, we performed RNA sequencing analysis of sorted CD34 +CD38 - cells expressing PINK1 shRNAs. This analysis revealed a marked decrease in the expression of MYC target genes, with TERT (Telomerase Reverse Transcriptase) being the most downregulated gene. Consistent with the role of TERT in telomere maintenance and telomere shortening as a trigger of senescence, we found that PINK1 knockdown decreased telomere length in CD34 +CD38 - cells, and overexpression of TERT effectively rescued the senescence phenotype. These findings collectively indicate that inhibition of PINK1-dependent mitochondrial quality control pathways induces senescence of LSCs through telomere shortening. To determine whether these changes translated to a reduction in functional LSC activity, we performed colony forming unit assays and serial xenotransplantation assays in immunodeficient NSG mice. Depletion of PINK1reduced the colony forming capacity and engraftment potential of 3 primary AML samples in primary and secondary recipients. Importantly, PINK1 depletion had minimal impact on the colony forming capacity and engraftment potential of normal CD34 + hematopoietic stem and progenitor cells (HSPCs) derived from cord blood, suggestive of a therapeutic window in vivo. In summary, our results demonstrate that mitochondrial quality control pathways regulate cell fate decision in LSCs. Inhibition of PINK1 activity impairs LSC activity by inducing senescence, while sparing normal HSPCs. Our findings provide the basis for exploring PINK1 as a therapeutic target against LSCs in AML. Disclosures Chan: AbbVie: Research Funding; BMS: Research Funding.

Abstract A87: Targeting the mitochondrial quality control machinery in acute myeloid leukemia

2016 ◽  
Author(s):  
Danny V. Jeyaraju ◽  
Veronique Voisin ◽  
Ashwin Ramakrishnan ◽  
Rose Hurren ◽  
Neil Maclean ◽  
...  
Keyword(s):  
Quality Control ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Mitochondrial Quality Control ◽  
Acute Myeloid

scholarly journals Pre-Transplant Monocytic Myeloid-Derived Suppressor Cell Frequency Has No Prognostic Role for Outcome after Allogeneic Hematopoietic Cell Transplantation for Acute Myeloid Leukemia in Remission

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5255-5255
Author(s):  
Colin Godwin ◽  
Jonathan R. Fromm ◽  
Brenda M. Sandmaier ◽  
Marco Mielcarek ◽  
Brent Wood ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Hematopoietic Cell Transplantation ◽  
Median Frequency ◽  
Prognostic Role ◽  
Support Research ◽  
Acute Myeloid

Abstract INTRODUCTION: Emerging data indicate myeloid-derived suppressor cells (MDSCs) adversely impact outcomes of patients with a variety of malignancies. However, it is less clear how MDSCs affect acute myeloid leukemia (AML) disease biology or the response of AML patients to treatment. Here, we studied a cohort of people with AML undergoing hematopoietic cell transplantation (HCT) in first complete remission (CR1) to examine the relationship between the monocytic subtype of MDSCs (M-MDSCs), pre-transplant measurable residual disease (MRD) status, and outcome after HCT. PATIENTS AND METHODS: Adults ≥18 years of age were included if they underwent first allogeneic HCT with myeloablative or nonmyeloablative conditioning for AML in CR1 from April 2006 until October 2014. Prospective MRD testing in bone marrow aspirates was performed routinely via 10-color multiparameter flow cytometry (MFC) as part of the pre-transplant work-up. Pre-transplant MFC data were used retrospectively to quantify M-MDSCs as the proportion of monocytes (identified by side scatter properties and CD14 positivity) with low or negative expression of HLA-DR. M-MDSC frequency was then expressed as a percentage of the total number of viable cells in the sample. Available combinations of antigens measured by MFC did not allow for the identification of other MDSC subsets (e.g. granulocytic MDSCs). RESULTS: We identified 349 adults undergoing allogeneic HCT for AML in CR1 for whom pre-transplant MRD testing was performed and for whom follow-up data were available. Of these, 8 had to be excluded because of insufficient MFC events available for identification of M-MDSCs. In the remaining 341 patients, M-MDSC frequency ranged from <0.001% to 6.53%, with a median of 0.18% (25th percentile: 0.06%; 75th percentile: 0.40%). Patients with lower (i.e. <median) frequency of M-MDSCs were less likely male (p=0.01) and more likely had recovered neutrophil and platelet counts (p=0.001) than patients with higher (i.e. ≥median) frequency of M-MDSCs. There was no difference with regard to all other examined characteristics (age, WBC and cytogenetic risk at diagnosis, type of AML, median CR duration before HCT, donor type, and conditioning intensity). The proportion of MRD positive ("MRDpos") patients was similar between those with lower vs. higher M-MDSC frequency (18.8 vs. 24.6%, p=0.20). Moreover, while MRD negative ("MRDneg") patients (n=267) differed statistically significantly from MRDpos patients (n=74) with regard to several characteristics such as more favorable disease risk and lower proportion of secondary AML, there was only a statistically non-significant trend toward lower M-MDSC frequency in MRDneg patients (0.16% [range <0.001-5.61%] vs. 0.22% [range <0.001-6.53%], p=0.09). The median follow-up time after HCT among all survivors was 5.8 (range, 2.0-11.4) years. The time was slightly longer for survivors with lower compared to those with higher M-MDSC frequency (6.1 [range 2.6-11.4] vs. 5.1 [range 2.0-11.3] years; p=0.0076). Stratified by the median M-MDSC frequency, the 3-year estimates of overall survival were similar for patients with lower and higher pre-HCT M-MDSCs (58.2% [95% confidence interval 50.4-65.2%] vs. 57.6% [49.8-64.7%]), as were 3-year estimates for relapse free survival (53.5% [45.7-60.7%] vs. 48.3% [40.6-55.6%]), 3-year estimates of the cumulative incidence of relapse (31.8% [24.9-38.8%] vs. 34.6% [27.6-41.8%]), and 3-year estimates of non-relapse mortality (14.7% [9.9-20.5%] vs. 17.0% [11.8-23.0%]). Analyses restricted to the subset of patients undergoing myeloablative (MA) conditioning or those undergoing MA conditioning in MRDneg remission showed qualitatively similar results. CONCLUSIONS: In the largest study to date examining the role of M-MDSCs in AML, we found no convincing evidence for a prognostic role of these cells for adults undergoing allografting in CR1. Disclosures Walter: Actinium Pharmaceuticals, Inc.: Other: Clinical trial support, Research Funding; Amgen Inc.: Other: Clinical trial support, Research Funding; Amphivena Therapeutics: Consultancy, Equity Ownership, Other: Clinical trial support, Research Funding; Aptevo Therapeutic: Consultancy, Other: Clinical trial support, Research Funding; Covagen AG: Consultancy, Other: Clinical trial support, Research Funding; Seattle Genetics, Inc.: Consultancy, Other: Clinical trial support, Research Funding; Boehringer Ingelheim Pharma GmbH & Co. KG: Consultancy; Pfizer: Consultancy.

Mir-223 Is Dispensable for the Onset of Acute Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 501-501 ◽  
Author(s):  
Florian Kuchenbauer ◽  
Tobias Berg ◽  
Sarah M Mah ◽  
Milijana mirkovic-Hosle ◽  
Anisa Salmi ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Model Systems ◽  
Cell Phenotype ◽  
Leukemic Transformation ◽  
Self Renewal ◽  
Colony Forming Capacity ◽  
Acute Myeloid

Abstract Abstract 501 The functional roles of microRNAs in the development of acute myeloid leukemia (AML) are not yet clear. Due to its myeloid-specific expression, miR-223 has been one of the most-investigated miRNAs in normal and malignant hematopoiesis. However, the role of miR-223 in myeloid differentiation is not completely understood, as contradicting data exists. Genetic depletion of miR-223 led to a significant increase of myeloid progenitor cells as well as circulating hyperreactive neutrophils. Here, we investigate the role of miR-223 in the development of AML in vivo, using retroviral overexpression models of Hoxa9 with Meis1 or MN1 as two potent models of leukemic transformation in a miR-223+/+ or miR-223−/− background. In contrast to the observed high level expression of miR-223 in human CD34- bulk AML cells (p=0.0106), we could show that miR-223 was dispensable for the development of AML and did not impact on either the leukemic stem cell frequency nor the AML cell phenotype in Hoxa9-Meis1 AML cells. While these findings reveal that miR-223 is not necessary for leukemic transformation in highly aggressive AML models, we became interested if miR-223 functions rather as modulator of disease progression, especially at the early development of AML. Therefore, we investigated the role of miR-223 with regards to differentiation and self-renewal in two preleukemic model systems by retrovirally infecting miR-223−/− and miR-223+/+ BM cells with AML1-ETO and Hoxa9 respectively. Characterization of these models demonstrated that miR-223 expression is a determinant of differentiation, as miR-223−/− preleukemic cells exhibit a significant lower Mac-1 expression (p=0.0003). However, in contrast to normal miR-223−/− BM cells, which show a significantly higher colony forming capacity in methylcellulose compared to miR-233+/+ BM cells, the colony forming capacity of miR-223−/− or miR-223+/+ preleukemic cells did not significantly change. These findings demonstrate that miRNA miR-223 is hierarchically expressed in AML cells, and functionally link miR-223 to impaired differentiation rather than increased self-renewal in the initiation of AML. This indicates that miR-223 is more likely a fine tuner of leukemic development than a potent tumor suppressor or oncogenes as suggested in the literature. However, it still remains to be shown if the presence of miR-223 influences the susceptibility of preleukemic cells to convert into leukemia initiating cells. Disclosures: No relevant conflicts of interest to declare.

Intricate role of mitochondrial calcium signalling in mitochondrial quality control for regulation of cancer cell fate

Mitochondrion ◽  
2021 ◽  
Vol 57 ◽  
pp. 230-240
Author(s):  
Srimanta Patra ◽  
Kewal Kumar Mahapatra ◽  
Prakash Priyadarshi Praharaj ◽  
Debasna Pritimanjari Panigrahi ◽  
Chandra Sekhar Bhol ◽  
...  
Keyword(s):  
Quality Control ◽  
Cell Fate ◽  
Cancer Cell ◽  
Calcium Signalling ◽  
Mitochondrial Calcium ◽  
Mitochondrial Quality Control

scholarly journals NK Cells of Acute Myeloid Leukemia Patients Exhibit Exhausted Phenotype with Impaired Functional Activity

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4466-4466
Author(s):  
Dmitry Zhigarev ◽  
Alexander W. MacFarlane ◽  
Christina Diane Drenberg ◽  
Reza Nejati ◽  
Asya Varshavsky ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Surface Expression ◽  
Healthy Controls ◽  
Healthy Donors ◽  
Activating Receptor ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) accounts for about one third of all leukemias, with half of all leukemia deaths. The low 5-year survival rate and manifestation of this deadly disease in old age reinforce the need for new safe and effective AML therapies. Considering the exceptional role of immune cells in the recognition and elimination of tumor cells, one of these methods is immunotherapy. However, for the development of immunotherapeutic approaches, it is necessary to clearly understand the role of certain effector cells in the pathogenesis of the disease, as well as to have the knowledge about the phenotypic characteristics of these cells. Natural killer (NK) cells play important roles in innate cancer immunosurveillance, and some published data indicate that the antitumor function of NK cells is reduced in AML patients. To expand upon previous work, we performed a comprehensive analysis of the phenotypic and functional characteristics of NK cells in previously untreated AML patients that took into account a wide variety of biomarkers. The goals of this study were to define the phenotypic and functional differences in NK cells from AML patients and healthy donors and determine how these parameters affect outcome of the disease. We used 14-color flow cytometry to assess more than 30 measurable markers on NK cells from the peripheral blood of 33 untreated AML patients and age-matched healthy controls. In addition, NK cells were tested for interferon-γ responses under antibody-dependent cellular cytotoxicity conditions. Results in AML patients were then compared to healthy donors. We found that the NK cells of patients with AML have a significantly lower capacity to secrete IFN-γ and showed numerous signs of an exhausted phenotype, as compared to healthy controls. These included increased surface expression of CD39, PD-1, and LILRB1 on NK cells from AML patients. Interestingly, surface expression of the TIGIT checkpoint receptor did not differ between AML patients and healthy donors, but surface expression of the activating receptor DNAM-1, which shares the same ligands on tumor cells, was decreased. All of these data confirm that the NK cells of AML patients are functionally impaired. We also noted that the frequency of CD57 + NKG2C + KIR + memory-like "adaptive" NK cells was greater in the blood of AML patients. The proportion of adaptive NK cells did not correlate with the age of donors. Phenotypic features of this cell subpopulation from the AML patients included significantly increased expression levels of CD56 and significantly lower expression of the activating receptor DNAM-1. Disclosures Zhigarev: Janssen R&D: Research Funding; Immunitas Therapeutics: Consultancy; Tavotek Biotherapeutics: Consultancy. Drenberg: Janssen R&D: Current Employment. Campbell: Janssen R&D: Research Funding.

Osteopontin - A New Angiogenic Factor Which Correlates with Circulating Endothelial Cells in Acute Myeloid Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1004-1004
Author(s):  
Agnieszka Wierzbowska ◽  
Magdalena Czemerska ◽  
Anna Krawczyńska ◽  
Agnieszka Pluta ◽  
Anna Szmigielska ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Significant Positive Correlation ◽  
Circulating Endothelial Cells ◽  
Response To Treatment ◽  
Positive Correlation ◽  
Ldh Activity ◽  
Acute Myeloid

Abstract Abstract 1004 Poster Board I-26 Objectives: There is evidence that acute myeloid leukemia (AML) development and progression could be determined by the expression profiling of specific angiogenic proteins. Previously we have found that the number of circulating endothelial cells (CEC) and endothelial progenitors (CEP) in peripheral blood of AML patients is a good noninvasive marker of angiogenesis and correlates with tumor mass and response to treatment. Osteopontin (OPN) is hematopoietic stem cell niche component which controls tumor growth and angiogenesis. It promotes VEGF dependent tumor progression, induces endothelial cell survival and migration and modulates expression of angiopoietins. The role of OPN in AML is unknown. We evaluated the level of circulating OPN, angiopoietin-1 (ANG-1) and ANG-2 in AML patients. In addition we correlated the levels of angiogenic cytokines with CEC number, known prognostic factors and response to treatment. Methods: OPN, ANG-1 and ANG-2 were measured in plasma samples in 69 newly diagnosed AML patients with median age 53 (range 18-78 years) and 16 controls with median age 36 (range 22-73 years) using enzyme-linked immunosorbent assay (ELISA). According to median level of cytokines patients were subdivided into “low-expressers” and “high”-expressers group. CEC were evaluated by the four colour flow cytometry using a panel of previously described monoclonal antibodies. CEC deriving from angiogenic microvessels were characterized by CD36 expression. Results: The median levels of circulating OPN (162,5 pg/ml) and ANG-2 (5184 pg/ml) were significantly higher in AML patients as compared to healthy controls (70 pg/ml; p<0.0001 and 2624,3 pg/ml; p<0.001 respectively). In contrast, the level of ANG-1 in AML pts (1038 pg/ml) was lower than in control group (1710 pg/ml; p<0.002). OPN plasma level was significantly higher in AML patients with more than 50% of blasts in the bone marrow (197 pg/ml) and elevated LDH activity (170 pg/ml) compared to group with BM blasts <50% (152 pg/ml; p<0.05) and normal LDH (137,5 pg/ml; p<0.03). In analogy, we found the significant positive correlation between ANG-2, but not ANG-1, with WBC count (p=0.05), circulating blast count (CBC) (p<0.005) and LDH activity (p=0.05). There was no statistical association between the levels of OPN, ANG-1, and ANG-2, and patients' age, sex, AML subtype according FAB classification and cytogenetic risk group. Interestingly, in AML patients OPN level correlated positively with the number of CEC deriving from angiogenic microvessels (p<0.02). Moreover, we observed tendency to positive correlation between ANG-2 level and CD36+ CEC count (p=0.09). In addition, in AML we have found significant positive correlation between OPN and ANG-2 level (p<0.03). From the 49 patients receiving intensive induction chemotherapy, 28 (56%) achieved complete remission (CR). We observed that the CR rate in “low-expressers” of OPN (67%) was higher than in the “high-expressers” (33%), however a difference did not reached statistical significance. This may be due to not very large number of evaluated patients. Conclusions: The levels of circulating OPN and ANG-2, but not ANG-1, are significantly higher in AML patients than in healthy subjects and correlate with tumor burden as well as the number of “angiogenic” circulating endothelial cells. This data clearly demonstrate an important role of circulating OPN as well as ANG-2 in angiogenesis and AML biology. A better understanding of precise functions of OPN and angiopoietins may create new options for therapeutic interventions in AML. Disclosures: Robak: Celgene: Consultancy; Roche: Honoraria, Research Funding; Genmab: Research Funding; Cambridge Antibody Technology: Research Funding; GlaxoSmithKline: Honoraria.

Role of FLT3 gene mutations in acute myeloid leukemia: effect on course of disease and results of therapy

2019 ◽  
Vol XIV (1) ◽  
Author(s):  
A.M. Radzhabova ◽  
S.V. Voloshin ◽  
I.S. Martynkevich ◽  
A.A. Kuzyaeva ◽  
V.A. Shuvaev ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Gene Mutations ◽  
Course Of Disease ◽  
Acute Myeloid

scholarly journals The Role of Hypoxic Bone Marrow Microenvironment in Acute Myeloid Leukemia and Future Therapeutic Opportunities

2021 ◽  
Vol 22 (13) ◽  
pp. 6857
Author(s):  
Samantha Bruno ◽  
Manuela Mancini ◽  
Sara De Santis ◽  
Cecilia Monaldi ◽  
Michele Cavo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Cell Fate ◽  
Myeloid Leukemia ◽  
Hematologic Malignancy ◽  
Bone Marrow Microenvironment ◽  
Metabolic Adaptation ◽  
Cell Fate Decisions ◽  
Wide Range ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a hematologic malignancy caused by a wide range of alterations responsible for a high grade of heterogeneity among patients. Several studies have demonstrated that the hypoxic bone marrow microenvironment (BMM) plays a crucial role in AML pathogenesis and therapy response. This review article summarizes the current literature regarding the effects of the dynamic crosstalk between leukemic stem cells (LSCs) and hypoxic BMM. The interaction between LSCs and hypoxic BMM regulates fundamental cell fate decisions, including survival, self-renewal, and proliferation capacity as a consequence of genetic, transcriptional, and metabolic adaptation of LSCs mediated by hypoxia-inducible factors (HIFs). HIF-1α and some of their targets have been associated with poor prognosis in AML. It has been demonstrated that the hypoxic BMM creates a protective niche that mediates resistance to therapy. Therefore, we also highlight how hypoxia hallmarks might be targeted in the future to hit the leukemic population to improve AML patient outcomes.

Sign in / Sign up

Export Citation Format

Share Document