scholarly journals The Role of ARHGAP9: Clinical Implication and Potential Function in Acute Myeloid Leukemia

2020 ◽  
Author(s):  
Caixia Han ◽  
Shujiao He ◽  
Ruiqi Wang ◽  
Xuefeng Gao ◽  
Hong Wang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Clinicopathological Parameters ◽  
Published Data ◽  
Hub Genes ◽  
Hematopoietic Stem ◽  
Over Expression ◽  
Significant Difference ◽  
Acute Myeloid

Abstract Background: Rho GTPase activating protein 9 (ARHGAP9) is expressed in many cancers and can inactivate Rho GTPases that are key regulators of cytoskeletal dynamics. However, the exact role of ARHGAP9 in acute myeloid leukemia (AML) is still unclear. Methods: We compared the transcriptional expression, prognosis, differentially expressed genes, function enrichment, and hub genes in AML patients based on published data in UALCAN, GEPIA, Gene Expression Omnibus (GEO), the Human Protein Atlas (HPA), Cancer Cell Line Encyclopedia (CCLE), LinkedOmics, Metascape, and String databases. Data from the Cancer Genome Atlas (TCGA) database was used to evaluate the correlations between ARHGAP9 expression and various clinicopathological parameters as well as the significantly different genes associated with ARHGAP9 expression.Results: We found that ARHGAP9 expression was higher in AML patient tissues and cell lines than the corresponding control tissues and other cancer types. Furthermore, ARHGAP9 over-expression was associated with shorter overall survival (OS) in AML patients. Compared with the ARHGAP9low group, ARHGAP9high patients received only chemotherapy showed the significantly worse OS and event-free survival (EFS), but no significant difference after treatment with autologous or allogeneic hematopoietic stem cell transplantation (auto/allo-HSCT). In addition, ARHGAP9high patients undergoing auto/allo-HSCT had significantly better prognosis in OS and EFS than those receiving only chemotherapy. Because most of the overlapping gene between the significantly different genes and co-expression genes were enriched in the immune functions, suggesting an immune regulation potential of ARHGAP9 in AML. Thirty-two hub genes were identified from the differently expressed genes, within which the KIF20A had significant prognostic value for AML.Conclusions: Our results demonstrated that ARHGAP9 overexpression was associated with poor OS in AML patients and can be used as a prognosis biomarker. AML patients with ARHGAP9 over-expression could benefit from auto/allo-HSCT rather than chemotherapy.

scholarly journals The role of ARHGAP9: clinical implication and potential function in acute myeloid leukemia

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Caixia Han ◽  
Shujiao He ◽  
Ruiqi Wang ◽  
Xuefeng Gao ◽  
Hong Wang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Differentially Expressed Genes ◽  
Myeloid Leukemia ◽  
Functional Enrichment ◽  
Differentially Expressed ◽  
Clinicopathological Parameters ◽  
Hub Genes ◽  
Significant Difference ◽  
Acute Myeloid

Abstract Background Rho GTPase activating protein 9 (ARHGAP9) is expressed in various types of cancers and can inactivate Rho GTPases that mainly regulate cytoskeletal dynamics. However, the exact role of ARHGAP9 in acute myeloid leukemia (AML) has yet to be clarified. Methods We compared the transcriptional expression, prognosis, differentially expressed genes, functional enrichment, and hub genes in AML patients on the basis of the data published in the following databases: UALCAN, GEPIA, Gene Expression Omnibus, the Human Protein Atlas, Cancer Cell Line Encyclopedia, LinkedOmics, Metascape, and String. Data from the Cancer Genome Atlas database was used to evaluate the correlations between ARHGAP9 expression and various clinicopathological parameters, as well as the significantly different genes associated with ARHGAP9 expression. Results We found that ARHGAP9 expression was higher in the tissues and cell lines extracted from patients with AML than corresponding control tissues and other cancer types. ARHGAP9 overexpression was associated with decreased overall survival (OS) in AML. Compared with the ARHGAP9low group, the ARHGAP9high group, which received only chemotherapy, showed significantly worse OS and event-free survival (EFS); however, no significant difference was observed after treatment with autologous or allogeneic hematopoietic stem cell transplantation (auto/allo-HSCT). The ARHGAP9high patients undergoing auto/allo-HSCT also had a significantly better prognosis with respect to OS and EFS than those receiving only chemotherapy. Most overlapping genes of the significantly different genes and co-expression genes exhibited enriched immune functions, suggesting the immune regulation potential of ARHGAP9 in AML. A total of 32 hub genes were identified from the differentially expressed genes, within which the KIF20A had a significant prognostic value for AML. Conclusions ARHGAP9 overexpression was associated with poor OS in AML patients and can be used as a prognostic biomarker. AML patients with ARHGAP9 overexpression can benefit from auto/allo-HSCT rather than chemotherapy.

Alternative polyadenylation dysregulation contributes to the differentiation block of acute myeloid leukemia

Blood ◽  
2021 ◽  
Author(s):  
Amanda G Davis ◽  
Daniel T. Johnson ◽  
Dinghai Zheng ◽  
Ruijia Wang ◽  
Nathan D. Jayne ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Alternative Polyadenylation ◽  
Hematopoietic Stem ◽  
Global Trends ◽  
Protein Levels ◽  
Mtorc1 Signaling ◽  
Differentiation Block ◽  
Acute Myeloid

Post-transcriptional regulation has emerged as a driver for leukemia development and an avenue for therapeutic targeting. Among post-transcriptional processes, alternative polyadenylation (APA) is globally dysregulated across cancer types. However, limited studies have focused on the prevalence and role of APA in myeloid leukemia. Furthermore, it is poorly understood how altered poly(A) site (PAS) usage of individual genes contributes to malignancy or whether targeting global APA patterns might alter oncogenic potential. In this study, we examined global APA dysregulation in acute myeloid leukemia (AML) patients by performing 3' Region Extraction And Deep Sequencing (3'READS) on a subset of AML patient samples along with healthy hematopoietic stem and progenitor cells (HSPCs) and by analyzing publicly available data from a broad AML patient cohort. We show that patient cells exhibit global 3' untranslated region (UTR) shortening and coding sequence (CDS) lengthening due to differences in PAS usage. Among APA regulators, expression of FIP1L1, one of the core cleavage and polyadenylation factors, correlated with the degree of APA dysregulation in our 3'READS dataset. Targeting global APA by FIP1L1 knockdown reversed the global trends seen in patients. Importantly, FIP1L1 knockdown induced differentiation of t(8;21) cells by promoting 3'UTR lengthening and downregulation of the fusion oncoprotein AML1-ETO. In non-t(8;21) cells, FIP1L1 knockdown also promoted differentiation by attenuating mTORC1 signaling and reducing MYC protein levels. Our study provides mechanistic insights into the role of APA in AML pathogenesis and indicates that targeting global APA patterns can overcome the differentiation block of AML patients.

scholarly journals Gpr44 Mediates the Selenium-Dependent Anti-Leukemic Effect in Acute Myeloid Leukemia

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1835-1835
Author(s):  
Fenghua Qian ◽  
Fenghua Qian ◽  
Diwakar Tukaramrao ◽  
Jiayan Zhou ◽  
Nicole Palmiero ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Murine Model ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Pparγ Agonist ◽  
Acute Myeloid

Abstract Objectives The relapse of acute myeloid leukemia (AML) remains a significant concern due to persistent leukemia stem cells (LSCs) that are not targeted by existing therapies. LSCs show sensitivity to endogenous cyclopentenone prostaglandin J (CyPG) metabolites that are increased by dietary trace element selenium (Se), which is significantly decreased in AML patients. We investigated the anti-leukemic effect of Se supplementation in AML via mechanisms involving the activation of the membrane-bound G-protein coupled receptor 44 (Gpr44) and the intracellular receptor, peroxisome proliferator-activated receptor gamma (PPARγ), by endogenous CyPGs. Methods A murine model of AML generated by transplantation of hematopoietic stem cells (HSCs- WT or Gpr44−/−) expressing human MLL-AF9 fusion oncoprotein, in the following experiments: To investigate the effect of Se supplementation on the outcome of AML, donor mice were maintained on either Se-adequate (Se-A; 0.08–0.1 ppm Se) or Se-supplemented (Se-S; 0.4 ppm Se) diets. Complete cell counts in peripheral blood were analyzed by hemavet. LSCs in bone marrow and spleen were analyzed by flow cytometry. To determine the role of Gpr44 activation in AML, mice were treated with Gpr44 agonists, CyPGs. LSCs in bone marrow and spleen were analyzed. Mice transplanted with Gpr44−/- AML cells were compared with mice transplanted with wild type AML cells and the progression of the disease was followed as above. To determine the role of PPARγ activation in AML, PPARγ agonist (Rosiglitazone, 6 mg/kg, i.p, 14 d) and antagonist (GW9662, 1 mg/kg, i.p. once every other day, 7 injections) were applied to Se-S mice transplanted with Gpr44−/- AML cells and disease progression was followed. Results Se supplementation at supraphysiological levels alleviated the disease via the elimination of LSCs in a murine model of AML. CyPGs induced by Se supplementation mediate the apoptosis in LSCs via the activation of Gpr44 and PPARγ. Conclusions Endogenous CyPGs produced upon supplementation with Se at supraphysiological levels improved the outcome of AML by targeting LSCs to apoptosis via the activation of two receptors, Gpr44 and PPARg. Funding Sources NIH DK 07,7152; CA 175,576; CA 162,665. Office of Dietary Supplements, USDA Hatch funds PEN04605, Accession # 1,010,021 (KSP, RFP).

MicroRNA-29a Is An Oncogene in Acute Myeloid Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 683-683
Author(s):  
Christopher Y. Park ◽  
Yoon-Chi Han ◽  
Govind Bhagat ◽  
Jian-Bing Fan ◽  
Irving L Weissman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Hematopoietic Stem Cells ◽  
Mirna Expression ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Abstract microRNAs (miRNAs) are short, non-protein encoding RNAs that bind to the 3′UTR’s of target mRNAs and negatively regulate gene expression by facilitating mRNA degradation or translational inhibition. Aberrant miRNA expression is well-documented in both solid and hematopoietic malignancies, and a number of recent miRNA profiling studies have identified miRNAs associated with specific human acute myeloid leukemia (AML) cytogenetic groups as well as miRNAs that may prognosticate clinical outcomes in AML patients. Unfortunately, these studies do not directly address the functional role of miRNAs in AML. In fact, there is no direct functional evidence that miRNAs are required for AML development or maintenance. Herein, we report on our recent efforts to elucidate the role of miRNAs in AML stem cells. miRNA expression profiling of AML stem cells and their normal counterparts, hematopoietic stem cells (HSC) and committed progenitors, reveals that miR-29a is highly expressed in human hematopoietic stem cells (HSC) and human AML relative to normal committed progenitors. Ectopic expression of miR-29a in mouse HSC/progenitors is sufficient to induce a myeloproliferative disorder (MPD) that progresses to AML. During the MPD phase of the disease, miR-29a alters the composition of committed myeloid progenitors, significantly expedites cell cycle progression, and promotes proliferation of hematopoietic progenitors at the level of the multipotent progenitor (MPP). These changes are manifested pathologically by marked granulocytic and megakaryocytic hyperplasia with hepatosplenomegaly. Mice with miR-29a-induced MPD uniformly progress to an AML that contains a leukemia stem cell (LSC) population that can serially transplant disease with as few as 20 purified LSC. Gene expression analysis reveals multiple tumor suppressors and cell cycle regulators downregulated in miR-29a expressing cells compared to wild type. We have demonstrated that one of these genes, Hbp1, is a bona fide miR-29a target, but knockdown of Hbp1 in vivo does not recapitulate the miR-29a phenotype. These data indicate that additional genes are required for miR-29a’s leukemogenic activity. In summary, our data demonstrate that miR-29a regulates early events in normal hematopoiesis and promotes myeloid differentiation and expansion. Moreover, they establish that misexpression of a single miRNA is sufficient to drive leukemogenesis, suggesting that therapeutic targeting of miRNAs may be an effective means of treating myeloid leukemias.

scholarly journals A New Entity of Acute Myeloid Leukemia Driven By Epigenetic and Somatic Dis-Regulation of Uncx, a Novel Homeobox Transcription Factor Gene

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1356-1356
Author(s):  
Giulia Daniele ◽  
Clelia Tiziana Storlazzi ◽  
Cristina Papayannidis ◽  
Ilaria Iacobucci ◽  
Angelo Lonoce ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Transcription Factor ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Ectopic Expression ◽  
Response To Therapy ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Abstract We describe a new AML entity, occurring in 30% of de novo acute myeloid leukemia, due to structural and epigenetic deregulation of the UNCX homeobox (HB) gene. By molecular approaches, we identified a M5 AML patient with a t(7;10)(p22;p14) translocation as the sole cytogenetic anomaly and showing ectopic expression of UNCX (7p22.3), which encode for a transcription factor involved in somitogenesis and neurogenesis. Since UNCX was never reported in association with cancer but only with common myeloid cell proliferation and regulation of cell differentiation, we decided to investigate its contribution to leukemogenesis. We observed UNCX ectopic expression in 32.3% (20/62) and in 8% (6/75) of acute myeloid leukemia (AML) patients and cell lines, respectively. Notably, retroviral-mediated UNCX transfer in CD34+ HSCs induced a slow-down in their proliferation and differentiation and transduced cells showed a lower growth rate but a higher percentage of CD34+ stem cells in liquid culture than controls. Additionally, UNCX infected cells displayed a decrease of MAP2K1 proliferation marker but increase of KLF4, HOXA10, and CCNA1, associated with impaired differentiation and pluripotency. Similarly, UNCX-positive patients revealed alteration of gene pathways involved in proliferation, cell cycle control and hematopoiesis. Since HB genes encode for transcription factors showing a crucial role in normal hematopoiesis and in leukemogenesis, we focused our attention on the role of altered UNCX expression level. Of note, its murine ortholog, (Uncx) was previously described as embedded within a low-methylated regions (≤ 10%) called "canyon" and dysregulated in murine hematopoietic stem cells (HSCs) as a consequence of altered methylation at canyons edges (borders) due to Dnmt3a inactivation. In our hands, UNCX activation was accompanied by methylation changes at both its canyon borders, clearly indicating an epigenetic regulation of this gene, although not induced by DNMT3A mutations. Clinical parameters and correlation with response to therapy will be presented. Taken together, our results indicate that more than 30% of de novo AML have a novel entity with a putative leukemogenic role of UNCX, whose activation may be ascribed to epigenetic regulators. Acknowledgments: MG, CP, GS, and AP(2) and this work was supported by ELN, AIL, AIRC, progetto Regione-Università 2010-12 (L. Bolondi), Fondazione del Monte di Bologna e Ravenna, FP7 NGS-PTL project. CTS, GD and AL are supported by Associazione Italiana Ricerca sul Cancro (AIRC) funding. Disclosures Nadarajah: MLL Munich Leukemia Laboratory: Employment. Martinelli:MSD: Consultancy; Novartis: Consultancy, Speakers Bureau; Ariad: Consultancy; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy; AMGEN: Consultancy; ROCHE: Consultancy.

Role of Gene Mutations in Adult Acute Myeloid Leukemia Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3373-3373
Author(s):  
Sheng-Chieh Chou ◽  
Jih-Luh Tang ◽  
Liang-In Lin ◽  
Hsin-An Hou ◽  
Chien-Yuan Chen ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Gene Mutations ◽  
Genetic Alterations ◽  
Prognostic Impact ◽  
Hematopoietic Stem ◽  
Wbc Count ◽  
Acute Myeloid

Abstract Abstract 3373 Poster Board III-261 Purpose Several gene mutations had been found to have clinical implications in patients with acute myeloid leukemia (AML), especially in those with normal karyotype. However, the role of such gene mutations for AML patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT) was unclear and inconclusive. We retrospectively evaluated the prognostic impact of 8 gene mutations in adult AML patients undergoing allo-HSCT. Materials & Methods From 1995 to 2007, a total of 463 consecutive adult patients with de novo non-M3 AML had comprehensive gene mutation analyses at the National Taiwan University Hospital. Three hundred and twenty five patients who received conventional induction chemotherapy were enrolled in this study. Those who received only low dose chemotherapy or palliative treatment were excluded. The genetic alterations analyzed included NPM1, FLT3/ITD, FLT3/TKD, CEBPA, AML1/RUNX1, RAS, MLL/PTD, and WT1. The clinical implication of these genetic alterations in the patients receiving allo-HSCT was analyzed, and the result was compared with that in patients without allo-HSCT. Results The clinical characteristics in the patients receiving allo-HSCT (n=100) and those without (n=225) were similar with the exception of age, being younger in the former group (35.4 years vs. 49.5 years p<0.001). In univariate analysis, older age (Age > 45 years), higher initial WBC count (WBC>50K/μL), elevated LDH level, unfavorable karyotype, FLT3/ITD, mutations of AML1/RUNX1 were significantly associated with poorer overall survival (OS) in patients not receiving allo-HSCT; While NPM1mut/FLT3ITDneg and CEBPA mutations served as significantly good prognostic indicators. In multivariate analysis, age, WBC count, karyotype, FLT3/ITD, AML1/RUNX1, CEBPA and NPM1mut/FLT3ITDneg remained to be independent prognostic factors in non-allo-HSCT patients. However, in patients receiving allo-HSCT, only unfavorable karyotype and disease status (refractory or remission) at the time of transplantation were associated with poorer OS both in univariate and multivariate analyses. The similar prognostic impact of FLT3/ITD, CEBPA, AML1/RUNX1 and NPM1 on OS was not seen in patients receiving allo-HSCT. Furthermore, in contrast to its poor prognostic impact in non-allo-HSCT patients, mutation of AML1/RUNX1 was a significant good prognostic factor for relapse free survival (p=0.046), although not for OS, in allo-HSCT group. Conclusion FLT3/ITD, mutations of AML1/RUNX1, CEBPA and NPM1 have great prognostic implication for OS in AML patients not receiving allo-HSCT. However, their impact on OS is ameliorated in patients receiving allo-HSCT. The results need to be confirmed by further studies on more patients. Disclosures: No relevant conflicts of interest to declare.

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