Acute Myeloid Leukemia Cells Acquire Chemo-Resistance By Inducing Osteoblast Differentiation in Mesenchymal Stem Cells through up-Regulation of RUNX2

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2929-2929
Author(s):  
Venkata Lokesh Battula ◽  
Phuong M Le ◽  
Jeffrey Sun ◽  
Teresa McQueen ◽  
Anitha Somanchi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Alkaline Phosphatase ◽  
Acute Myeloid Leukemia ◽  
Transcription Factor ◽  
Cell Surface ◽  
Myeloid Leukemia ◽  
Osteoblast Differentiation ◽  
Leukemia Cells ◽  
Acute Myeloid

Abstract The leukemia bone marrow micro-environment (BME) is comprised of the endosteal and vascular niches, provides vital support for cellular growth and conveys drug resistance to leukemia cells. Several reports suggest that mesenchymal stem/stromal cells (MSCs) present in the bone marrow niche induce cell survival and anti-apoptotic proteins in acute myeloid leukemia (AML) cells and protect them from chemotherapy. The mechanisms underlying BME-mediated chemo-resistance however have not been fully elucidated. Here, we hypothesize that AML cells induce functional changes and prime MSCs to protect leukemia cells from chemotherapy. To test our hypothesis, we have compared age matched (between 40-60 years) bone marrow derived MSCs from AML patients (AML-MSC, n=10) and normal (N-MSC, n=10) individuals and analyzed their proliferation, cell surface phenotype, multi-lineage differentiation and chemo-protection potential. AML-MSCs are phenotypically different, with their polygonal morphology and larger cell size compared to N-MSCs which are elongated and spindle shaped appearance. The average cell doubling time of AML-MSCs is 52±8hrs compared to 34±6hours for N-MSCs during their exponential growth phase (p<0.01). Cell surface phenotyping by flow cytometry revealed that most of the markers known to be expressed on N-MSCs including CD105, CD90, CD73, CD51, CD44, SUSD2, CD106, CD140b, CD140a, CD106 and CD271 were also expressed on AML-MSCs at similar levels. Interestingly, tissue non-specific alkaline phosphatase (TNAP, clone W8B2), a cell surface protein highly expressed in naïve-MSCs and osteoblast progenitors (Battula VL et al., Haematologica, 2009) was 10-14 fold higher in AML- as compared to N-MSCs. Since TNAP is also a osteoblast specific marker, we compared osteoblast differentiation potential of N- vs AML-MSCs. Surprisingly, a dramatic increase in alkaline phosphatase activity (by BCIP/NBT substrate) was observed in AML-MSCs even without induction of osteoblast differentiation. mRNA analysis by qRT-PCR revealed that osteoblast specific genes including osteopontin, TNAP, osteocalcin, and osterix were 5-10 fold up-regulated in AML-MSCs compared to N-MSCs before induction. In N-MSCs, the expression of these markers was induced only under osteoblast differentiation conditions. These data indicate that AML-MSCs are primed to differentiate into-osteoblasts. Adipocyte differentiation was assessed by Oil-Red O staining for lipid droplets and revealed a > 95% reduction (p<0.0001) in the number mature adipocytes in AML-MSCs compared to N-MSCs suggesting that AML-MSCs lack the ability to differentiate into adipocytes. To understand the mechanism inducing osteogenic specific differentiation of AML-MSCs, we performed mRNA expression analysis of genes that regulate this process. We found RUNX2, a transcription factor that induces osteogenic but inhibits adipogenic differentiation, was 4-5 fold increased in AML-MSCs compared to N-MSCs. To validate these observations, we co-cultured N-MSCs in the presence or absence of OCI-AML3 cells for 3-5 days and FACS sorted the MSCs for gene expression analysis. We observed a 3-4 fold up-regulation of TNAP protein expression by flow cytometry and 4-6 fold up-regulation of osteoblast specific markers including osteopontin, alkaline phosphatase and osterix in MSCs co-cultured with OCI-AML3 cells. In addition, RUNX2 was up-regulated in MSCs when co-cultured with OCI-AML3 cells. These data suggest that AML cells induce osteogenic differentiation in BM-MSCs by up-regulation of RUNX2. To identify the clinical significance of these observations, we examined the ability of AML- and N-MSCs to protect AML cells from chemotherapy. Co-culture of OCI-AML3 cells with either AML- or N-MSCs and treatment with Cytarabine revealed a 15±4.5% increase in the number of live leukemia cells when co-cultured with AML-MSCs compared to N-MSCs. These data indicate that AML-MSCs protect leukemia cells better from chemotherapy than normal MSCs. In conclusion, AML cells induce osteogenic differentiation in MSCs through up-regulation of the RUNX2 transcription factor. Increased chemo-protection of AML cells by AML-MSCs suggests a prominent role of these cells in AML relapse. Targeting RUNX2 and thereby inhibition of osteoblast differentiation of MSCs may provide enhanced treatment options for AML therapy. Disclosures No relevant conflicts of interest to declare.

scholarly journals A Novel CD49d Targeting Antisense, ATL1102, Effectively Mobilizes Acute Myeloid Leukemia Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3807-3807
Author(s):  
Yann Duchartre ◽  
EunJi Gang ◽  
Hye Na Kim ◽  
Stephanie Nicole Shishido ◽  
Muller Fabbri ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Cell Line ◽  
Peripheral Blood ◽  
Myeloid Leukemia ◽  
Surface Expression ◽  
Leukemia Cells ◽  
Acute Myeloid

Abstract BACKGROUND: Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Acute myeloid leukemia comprises approximately one-fifth of pediatric leukemias and is the seventh most common pediatric malignancy. In children, relapse following primary therapy approaches 40%, and the 5-year event-free survival (EFS) rate is only approximately 50%. Treatment is dominated by generic chemotherapeutic agents. Novel therapeutic strategies are highly warranted. The bone marrow microenvironment has been shown to promote cell adhesion-mediated drug resistance in leukemia cells. Breaking adhesive bonds of AML cells with their protective niche to mobilize them from the bone marrow to the peripheral blood may make drug treatment more efficient. Our studies have suggested the adhesion molecule CD49d as an anchor molecule for ALL and AML cells in the bone marrow. However, as of today, no drug targeting CD49d is approved for use in leukemia. Here, we evaluate a novel human specific CD49d targeting antisense, ATL1102, in clinical development for Multiple Sclerosis, in human AML cells. METHODS: We determined CD49d expression in the human AML cell line HL-60 treated with a CD49d targeting antisense ATL1102 and antisense control by qPCR and flow cytometry. Annexin V/DAPI and BrdU stainings were used for viability determination and cell cycle assay respectively by flow cytometry. A NOD/SCID IL2Rγ-/- (NSG)xenograft model of human HL-60 cell line was used for an in vivo mobilization assay. RESULTS: To assess the on-target effect of ATL1102 on CD49d, HL-60 cells were nucleoporated with either ATL1102 or control antisense.mRNA expression of CD49dwas significantly decreased by ATL1102 treatment cells (85.2%±15.4 expression inhibition using ATL1102 1µM after 24h compared to control, p<0.001) as assessed by RT-PCR. The FACS analysis 72 hours after treatment revealed a significant decrease of surface expression of CD49d in a dose-dependent manner (99%±0.4 (1µM, *), 87.9%±8.7 (3µM) and 57.8%±7.2 ATL1102 (10µM, ***), 55.9±13.5 (30µM, **) vs 99.7%±0.1 for control antisense (30 µM), P<0.001, n=3). No significant effect on apoptosis or cell cycle was observed after ATL1102 treatment. We also evaluated the in vivo effect of ATL-1102 on mobilization of leukemia cells in a pilot experiment. For this purpose, HL-60 cells (5x106/per mouse) were injected via the tail vein in sublethally irradiated NSG mice. Presence of human ALL cells (hCD45) was determined weekly by flow cytometry of white blood cells isolated from peripheral blood (PB). 23 Days post-leukemia injection, mice were treated with either antisense control (CTRL) (n=3), ATL1102 (50mg/kg, n=2). Peripheral blood was drawn before and 24 hours after ATL1102-treatment. ATL1102 induced a strong mobilization of AML cells to the PB of leukemia-recipient mice compared to control antisense treated-mice (69.1% and 87.7% vs 1.1%, 0.2% and 28.1% for ATL1102 (50mg/ml) and CTRL treated-mice respectively. The mobilized cells show a decrease of surface expression of CD49d (16.8%±9.2% vs 32.8%±16.7%), although this was not of statistical significance in this pilot experiment. Experiments to repeat this assay with large numbers of mice are in progress as well as experiments to determine the initial location of the mobilized AML cells and synergy of ATL1102 with chemotherapy are ongoing. CONCLUSION: We demonstrate that ATL1102 can efficiently decrease CD49d expression in AML cell line in vitro and in vivo, and that ATL1102 leads to mobilization of AML cells to the peripheral blood. Disclosures Wayne: NIH: Patents & Royalties; Medimmune: Honoraria, Other: travel support, Research Funding; Kite Pharma: Honoraria, Other: travel support; Pfizer: Honoraria; Spectrum Pharmaceuticals: Honoraria, Other: travel support, Research Funding. Tachas:Antisense Therapeutics Ltd: Employment, Equity Ownership, Patents & Royalties.

scholarly journals Tissue-Nonspecific Alkaline Phosphatase Is Required for MC3T3 Osteoblast–Mediated Protection of Acute Myeloid Leukemia Cells from Apoptosis

2018 ◽  
Vol 201 (3) ◽  
pp. 1086-1096 ◽  
Author(s):  
Rosalie M. Sterner ◽  
Kimberly N. Kremer ◽  
Amel Dudakovic ◽  
Jennifer J. Westendorf ◽  
Andre J. van Wijnen ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Leukemia Cells ◽  
Acute Myeloid Leukemia Cells ◽  
Tissue Nonspecific Alkaline Phosphatase ◽  
Acute Myeloid

scholarly journals SETDB1 mediated histone H3 lysine 9 methylation suppresses MLL-fusion target expression and leukemic transformation

Haematologica ◽  
2019 ◽  
Vol 105 (9) ◽  
pp. 2273-2285 ◽  
Author(s):  
James Ropa ◽  
Nirmalya Saha ◽  
Hsiangyu Hu ◽  
Luke F. Peterson ◽  
Moshe Talpaz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Target Genes ◽  
Critical Role ◽  
High Expression ◽  
Leukemia Cells ◽  
Biological Impact ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Epigenetic regulators play a critical role in normal and malignant hematopoiesis. Deregulation, including epigenetic deregulation, of the HOXA gene cluster drives transformation of about 50% of acute myeloid leukemia. We recently showed that the Histone 3 Lysine 9 methyltransferase SETDB1 negatively regulates the expression of the pro-leukemic genes Hoxa9 and its cofactor Meis1 through deposition of promoter H3K9 trimethylation in MLL-AF9 leukemia cells. Here, we investigated the biological impact of altered SETDB1 expression and changes in H3K9 methylation on acute myeloid leukemia. We demonstrate that SETDB1 expression is correlated to disease status and overall survival in acute myeloid leukemia patients. We recapitulated these findings in mice, where high expression of SETDB1 delayed MLL-AF9 mediated disease progression by promoting differentiation of leukemia cells. We also explored the biological impact of treating normal and malignant hematopoietic cells with an H3K9 methyltransferase inhibitor, UNC0638. While myeloid leukemia cells demonstrate cytotoxicity to UNC0638 treatment, normal bone marrow cells exhibit an expansion of cKit+ hematopoietic stem and progenitor cells. Consistent with these data, we show that bone marrow treated with UNC0638 is more amenable to transformation by MLL-AF9. Next generation sequencing of leukemia cells shows that high expression of SETDB1 induces repressive changes to the promoter epigenome and downregulation of genes linked with acute myeloid leukemia, including Dock1 and the MLL-AF9 target genes Hoxa9, Six1, and others. These data reveal novel targets of SETDB1 in leukemia that point to a role for SETDB1 in negatively regulating pro-leukemic target genes and suppressing acute myeloid leukemia.

The Growth Inhibition and Apoptosis Induction of Acute Myeloid Leukemia Blast Population by the Blocking IGF-IR Pathway.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4515-4515
Author(s):  
Si Sun ◽  
Yanli He ◽  
Xingbing Wang ◽  
Wei Liu ◽  
Jun Liu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Bone Marrow Cells ◽  
Pi3k Pathway ◽  
Leukemia Cell Line ◽  
Free System ◽  
Acute Myeloid ◽  
Marrow Cells

Abstract The insulin-like growth factor-1receptor (IGF-1R) is overexpressed in a variety of tumors and has been associated with cancer development. Here, we analysis the IGF-IR expression on the bone marrow cells from 45 newly diagnosed patients with acute myeloid leukemia (AML) by flow cytometry. IGF-1R universally expressed on AML blasts and the leukemia cell line HL-60, did not show significant correlation with FAB subtypes. However, the bone marrow cells from AML patients with high myeloblast counts (&gt;80%) generally showed brighter IGF-IR expressions, which indicated the IGF-IR pathway might play an important role for AML blast proliferation and survival. Indeed, blocking the IGF-1R pathway by neutralizing monoclonal antibodies could reduce the proliferation of HL-60 cells by 38.28% at 48 hr. This inhibitory effect on blast growth was observed in 4 of 5 AML samples. In the same IGF-1R blocking treatment, the apoptosis of HL-60 cells was significantly induced, resulting in apoptosis of 57% of the cell population with the measurement of Annexin V vs PI staining by flow cytometry. The control contained only 20% apoptotic cells. We also demonstrated that the blockade of the IGF-1R pathway inhibited the phophorylation of the PI3K pathway component Akt in HL-60 cells when cultured in a serum free system with a supplement of 50ng/ml exogenous IGF. Since PI3K pathway activation greatly contributes to the proliferation, survival and drug resistance of AML, it is of interest to study whether blockading IGF-IR could also inhibit the PI3K pathway in primary AML blasts and synergize other anti-leukemia agents to improve the therapeutic effectiveness. Conclusions: IGF-IR may play an important role in the proliferation and survival of the AML blast population; Blocking the IGF-IR pathway could significantly inhibit the growth of AML blasts and considerably induce the apoptosis of AML blasts; IGF-IR could become a critical molecular target in anti-leukemia drug discovery.

Identifying Small Molecules That Overcome HoxA9-Mediated Differentiation Arrest in Acute Myeloid Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3513-3513
Author(s):  
David B. Sykes ◽  
Mark K Haynes ◽  
Nicola Tolliday ◽  
Anna Waller ◽  
Julien M Cobert ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Small Molecules ◽  
Cell Line ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Myeloid Differentiation ◽  
Prostacyclin Receptor ◽  
Acute Myeloid

Abstract Abstract 3513 AML in adults is a devastating disease with a 5-year survival rate of 25%. We lack new treatments for AML, and the chemotherapy standard of care remains unchanged in thirty years. One success story in the treatment of AML has been the discovery of drugs that trigger the differentiation of leukemic blasts in the small subset of patients with acute promyelocytic leukemia. However, differentiation therapy is unfortunately not available for the remaining 90% of non-APL acute myeloid leukemia patients. Understanding and targeting the mechanism of differentiation arrest in AML has been under investigation for more than four decades. There is growing evidence to support the role of the homeobox transcription factors in normal hematopoietic differentiation as well as malignant hematopoiesis. The persistent, and inappropriate, expression of the homeobox gene HoxA9 has been described in the majority of acute myeloid leukemias. This implicates HoxA9 dysregulation as a common pathway of differentiation arrest in myeloid leukemias and suggests that by understanding and targeting this pathway, one might be able to overcome differentiation arrest. In cultures of primary murine bone marrow, constitutive expression of HoxA9 blocks myeloid differentiation and results in the outgrowth of immature myeloid cell lines. The mechanism by which HoxA9 causes differentiation arrest is not known and no compounds exist that inhibit HoxA9. We developed a murine cell line model in which the cells were blocked in differentiation by a conditional version of HoxA9. In this system, an estrogen-dependent ER-HoxA9 protein was generated by fusion with the estrogen receptor hormone-binding domain. When expressed in cultures of primary murine bone marrow, immortalized myeloblast cell lines can grow indefinitely in the presence of stem cell factor and beta-estradiol. Upon removal of beta-estradiol, and inactivation of HoxA9, these cell lines undergo synchronous and terminal myeloid differentiation. We took advantage of an available transgenic mouse model in which GFP was expressed downstream of the lysozyme promoter, a promoter expressed only in mature neutrophils and macrophages. Cell lines derived from the bone marrow of this lysozyme-GFP mouse were GFP-negative at baseline and brightly GFP-positive upon differentiation. In this manner, we generated a cell line with a built-in reporter of differentiation. These cells formed the basis of a high-throughput screen in which cells were incubated with small molecules for a period of four days in 384-well plate format. The cells were assayed by multi-parameter flow cytometry to assess for toxicity and differentiation. Compounds that triggered green fluorescence were scored as “HITS” and their pro-differentiation effects confirmed by analysis of morphology and cell surface markers. Given the availability of cells and the simple and reliable assay, we performed both a pilot screen of small molecules at The Broad Institute as well as an extensive screen of the NIH Molecular Libraries Small Molecule Repository. The screen of more than 350,000 small molecules was carried out in collaboration with the University of New Mexico Center for Molecular Discovery. We have identified one lead class of compounds - prostacyclin agonists – capable of promoting myeloid differentiation in this cell line model of AML. Using a parallel cell line derived from a prostacyclin receptor knock-out mouse, we confirmed that activity was due to signaling through the prostacyclin receptor. The role of prostacyclin signaling in myeloid differentiation has not been previously described. Analysis of gene expression demonstrated that the expression of the prostacyclin receptor is seen in ∼60% of in primary human AML samples. This is a potentially exciting finding as prostacyclin agonists (e.g. treprostinil) are clinically relevant as well as FDA-approved. Their potential role in the treatment of acute myeloid leukemia is unknown. Here we present the details of our high-throughput flow cytometry system and preliminary identification of pro-differentiation agents in AML. If successful, we anticipate that one of these small molecules may offer insight into a mechanism for overcoming differentiation arrest, and may also translate into a novel, clinically relevant treatment for acute myeloid leukemia. Disclosures: Sklar: IntelliCyt: Founder of IntelliCyt, the company that sells the HyperCyt high-throughput flow cytometry system. Other. Zon:Fate Therapeutics: Founder Other.

A Novel Non-Genetic Photostable Approach to Labelling Acute Myeloid Leukemia and Bone Marrow Cells with Quantum Dots

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4818-4818
Author(s):  
Yanwen Zheng ◽  
Zhengwei Mao ◽  
Bin Yin
Keyword(s):  
Bone Marrow ◽  
Quantum Dots ◽  
Acute Myeloid Leukemia ◽  
Blood Cells ◽  
Myeloid Leukemia ◽  
Hematopoietic Cells ◽  
Leukemia Cell ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Acute Myeloid

Abstract Abstract 4818 Acute myeloid leukemia (AML) is a detrimental disease with difficult diagnosis and treatment. Understanding the biology of AML at the molecular and cellular levels would be essential to successful management of the disease. However, the notoriously known difficulty in manipulation of leukemia cells has long hindered the dissection of AML pathogenesis. The advent of CdSe/ZnS quantum dots (QDs) represents an important advancement in the research field of nanotechnology, which have recently also been applied for imaging of live cells. Here, we have introduced a non-genetic approach of marking blood cells, by taking advantage of QD technology. We compared QDs complexed with different vehicles, including a peptide Tat (QDs-Tat), cationic polymer Turbofect (QDs-Tf) and liposome Lipofectamine 2000 (QDs-Lip), in their abilities to mark cells. QDs-Tat showed the highest efficiency in delivery into hematopoietic cells, among the three vehicles. We then examined QDs-Tat labelling of leukemia cell lines, and found that QDs-Tat could label 293T, bone marrow (BM) cells, THP-1, MEG-01 and HL-60 with a decreasing efficiency. The efficiency of QDs-Tat delivery was dependent on the concentration of QDs-Tat applied, but not the length of incubation time. In addition, more uniform intracellular distributions of QDs in 293T and leukemia cells were obtained with QDs-Tat, compared with the granule-like formation obtained with QDs-Lip. Clearly, QD fluorescence was sharp and tolerant to repetitive photo excitations, and could be detected in 293T for up to one week following labelling. In summary, our results suggest that QDs have provided a photostable, non-genetic and transient approach that labels normal and malignant hematopoietic cells in a cell type-, vehicle-, and QD concentration-dependent manner. We expect for potentially wide applications of QDs as an easy and fast tool assisting investigations of various types of blood cells in the near future. Disclosures: No relevant conflicts of interest to declare.

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