scholarly journals Hsa_circ_0001947 suppresses acute myeloid leukemia progression by sponging hsa-miR-329-5p and regulating CREBRF expression

2019 ◽  
Author(s):  
Fengjiao Han ◽  
Chaoqin Zhong ◽  
Wei Li ◽  
Ruiqing Wang ◽  
Chen Zhang ◽  
...  

AbstractAcute myeloid leukemia (AML) is a heterogeneous group of diseases resulting from clonal transformation of hematopoietic precursors through the acquisition of chromosomal rearrangements and multiple gene mutations. Accumulating evidence has indicated that aberrantly expressed circular RNAs (circRNAs) are involved in cancer development and progression. However, their clinical values and biological roles in AML remain unclear. In this study, we identified the aberrantly down-regulated profile of hsa_circ_0001947 in AML through microarray analysis and validated it with quantitative reverse transcription polymerase chain reaction (qRT-PCR). Then, we explored the clinical significance, biological functions and regulatory mechanisms of hsa_circ_0001947 in AML patients. The results showed that lower hsa_circ_0001947 expression was positively correlated with higher leukemia cells in bone marrow or peripheral blood, indicating poor prognosis. Further, bioinformatics analysis demonstrated hsa_circ_0001947-hsa-miR-329-5p-CREBRF network. Down-regulation of hsa_circ_0001947 by siRNA promoted cell proliferation, inhibited apoptosis, reduced drug resistance of AML cells, and also decreased the expression of its targeted gene, CREBRF. The mimics of hsa-miR-329-5p reduced drug resistance and decreased the expression of CREBRF, while its inhibitor manifested anti-leukemia effects and increased CREBRF expression. In vivo studies revealed that silencing hsa_circ_0001947 promoted the tumor growth in BALB/c nude mice. Collectively, our findings suggest that hsa_circ_0001947 functions as a tumor inhibitor to suppress AML cell proliferation through hsa-miR-329-5p/CREBRF axis, which would be a novel target for AML therapy.

2018 ◽  
Vol 51 (2) ◽  
pp. 886-896 ◽  
Author(s):  
Xiaoya Dong ◽  
Zhigang Fang ◽  
Mingxue Yu ◽  
Ling Zhang ◽  
Ruozhi Xiao ◽  
...  

Background/Aims: Among different molecular candidates, there is growing data to support that long noncoding RNAs (lncRNAs) play a significant role in acute myeloid leukemia (AML). HOXA-AS2 is significantly overexpressed in a variety of tumors and associated with anti-cancer drug resistance, however, little is known regarding the expression and function of HOXA-AS2 in the chemoresistance of AML. In this study, we aimed to determine the role and molecular mechanism of HOXA-AS2 in adriamycin-based chemotherapy resistance in AML cells. Methods: Quantitative real-time PCR was used to detect HOXA-AS2 expression in the BM samples and ADR cell lines, U/A and T/A cells. Furthermore, the effects of HOXA-AS2 silencing on cell proliferation and apoptosis were assessed in vitro by CCK8 and flow cytometry, and on tumor growth in vivo. Furthermore, bioinformatics online programs predicted and luciferase reporter assay were used to validate the association of HOXA-AS2 and miR-520c-3p in AML. Results: In this study, we showed that HOXA-AS2 is significantly upregulated in BM samples from AML patients after treatment with adriamycin-based chemotherapy and in U/A and T/A cells. Knockdown of HOXA-AS2 inhibited ADR cell proliferation in vitro and in vivo and promoted apoptosis. Bioinformatics online programs predicted that HOXA-AS2 sponge miR-520c-3p at 3’-UTR with complementary binding sites, which was validated using luciferase reporter assay and anti-Ago2 RIP assay. HOXA-AS2 could negatively regulate the expression of miR-520c-3p in ADR cells. S100A4 was predicted as a downstream target of miR-520c-3p, which was confirmed by luciferase reporter assay. Conclusion: Our results suggest that HOXA-AS2 plays an important role in the resistance of AML cells to adriamycin. Thus, HOXA-AS2 may represent a therapeutic target for overcoming resistance to adriamycin-based chemotherapy in AML.


2018 ◽  
Vol 38 (20) ◽  
Author(s):  
Dong-Mei Wu ◽  
Xin Wen ◽  
Xin-Rui Han ◽  
Shan Wang ◽  
Yong-Jian Wang ◽  
...  

ABSTRACT In the current study, we were interested in exploring the molecular mechanism of circular RNA DLEU2 (circRNA-DLEU2) (hsa_circ_0000488) and microRNA 496 (miR-496), as well as PRKACB, in human acute myeloid leukemia (AML) cell activities. The RNA expression levels of circRNA-DLEU2, hsa-miR-496, and PRKACB were assessed by quantitative real-time PCR (qRT-PCR). The proliferation and apoptosis abilities of the cells were determined by CCK8 assay and flow cytometry analysis. Target relationships between circRNA-DLEU2 and miR-496, as well as PRKACB, were analyzed by luciferase reporter assay and probe assay. Immunoblotting assays were used to detect the protein expression level of PRKACB. We also did in vivo experiments to observe tumor formation after overexpression of circRNA-DLEU2. Our data showed that circRNA-DLEU2 was upregulated in AML tissues and cells, which promoted AML cell proliferation and inhibited cell apoptosis. circRNA-DLEU2 promoted AML tumor formation in vivo. miR-496 was inhibited by circRNA-DLEU2 and was downregulated in AML tissues. circRNA-DLEU2 inhibited miR-496 expression and promoted PRKACB expression. miR-496 antagonized the effects of PRKACB on MOLM-13 cell proliferation and apoptosis. Collectively, circRNA-DLEU2 accelerated human AML by suppressing miR-496 and promoting PRKACB expression.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Chong Wang ◽  
Lingling Li ◽  
Mengya Li ◽  
Weiqiong Wang ◽  
Yanfang Liu ◽  
...  

Abstract Background Long non-coding RNAs (lncRNAs) are biomarkers participating in multiple disease development including acute myeloid leukemia (AML). Here, we investigated molecular mechanism of X Inactive-Specific Transcript (XIST) in regulating cellular viability, apoptosis and drug resistance in AML. Methods XIST, miR-29a and myelocytomatosis oncogene (MYC) expression in AML bone marrow cells collected from 62 patients was evaluated by RT-qPCR and Western blot analysis. Besides, the relationship among XIST, miR-29a and MYC was analyzed by dual luciferase reporter assay, RIP, and RNA pull down assays. AML KG-1 cells were treated with anti-tumor drug Adriamycin. The role of XIST/miR-29a/MYC in cellular viability, apoptosis and drug resistance in AML was accessed via gain- and loss-of-function approaches. At last, we evaluated role of XIST/miR-29a/MYC on tumorigenesis in vivo. Results XIST and MYC were up-regulated, and miR-29a was down-regulated in AML bone marrow cells. Silencing XIST inhibited cellular activity and drug resistance but promoted cellular apoptosis of KG-1 cells by down-regulating MYC. XIST inhibited miR-29a expression to up-regulate MYC. Moreover, silencing XIST inhibited tumorigenesis of AML cells in vivo. Conclusions Overall, down-regulation of XIST decreased MYC expression through releasing the inhibition on miR-29a, thereby reducing drug resistance, inhibiting viability and promoting apoptosis of AML cells.


Epigenomics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 935-953 ◽  
Author(s):  
Fengjiao Han ◽  
Chaoqin Zhong ◽  
Wei Li ◽  
Ruiqing Wang ◽  
Chen Zhang ◽  
...  

Aim: Accumulating evidence has indicated that circular RNAs (circRNAs) are involved in cancer biology. However, their roles in acute myeloid leukemia (AML) remain unclear. Therefore, we aimed to define novel circRNAs involved the development and progression of AML. Materials & methods: We used circRNAs microarray to determine the differential expression profile. Quantitative reverse transcription PCR analyzed the expression of hsa_circ_0001947. The siRNA assesses the function of hsa_circ_0001947 in vitro and in vivo. A dual-luciferase and mimics/inhibitor were to determine the target gene relationship. Results: hsa_circ_0001947 functions as a tumor inhibitor to suppress AML cell proliferation through hsa-miR-329-5p/ CREBRF axis. Conclusion: hsa_circ_0001947 may be as a novel potential biomarker for the treatment of AML.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
María Luz Morales ◽  
Alicia Arenas ◽  
Alejandra Ortiz-Ruiz ◽  
Alejandra Leivas ◽  
Inmaculada Rapado ◽  
...  

AbstractFMS-like tyrosine kinase 3 (FLT3) is a key driver of acute myeloid leukemia (AML). Several tyrosine kinase inhibitors (TKIs) targeting FLT3 have been evaluated clinically, but their effects are limited when used in monotherapy due to the emergence of drug-resistance. Thus, a better understanding of drug-resistance pathways could be a good strategy to explore and evaluate new combinational therapies for AML. Here, we used phosphoproteomics to identify differentially-phosphorylated proteins in patients with AML and TKI resistance. We then studied resistance mechanisms in vitro and evaluated the efficacy and safety of rational combinational therapy in vitro, ex vivo and in vivo in mice. Proteomic and immunohistochemical studies showed the sustained activation of ERK1/2 in bone marrow samples of patients with AML after developing resistance to FLT3 inhibitors, which was identified as a common resistance pathway. We examined the concomitant inhibition of MEK-ERK1/2 and FLT3 as a strategy to overcome drug-resistance, finding that the MEK inhibitor trametinib remained potent in TKI-resistant cells and exerted strong synergy when combined with the TKI midostaurin in cells with mutated and wild-type FLT3. Importantly, this combination was not toxic to CD34+ cells from healthy donors, but produced survival improvements in vivo when compared with single therapy groups. Thus, our data point to trametinib plus midostaurin as a potentially beneficial therapy in patients with AML.


Blood ◽  
2010 ◽  
Vol 115 (16) ◽  
pp. 3341-3345 ◽  
Author(s):  
Ke Cheng ◽  
Paolo Sportoletti ◽  
Keisuke Ito ◽  
John G. Clohessy ◽  
Julie Teruya-Feldstein ◽  
...  

Abstract Although NPM1 gene mutations leading to aberrant cytoplasmic expression of nucleophosmin (NPMc+) are the most frequent genetic lesions in acute myeloid leukemia, there is yet no experimental model demonstrating their oncogenicity in vivo. We report the generation and characterization of a transgenic mouse model expressing the most frequent human NPMc+ mutation driven by the myeloid-specific human MRP8 promoter (hMRP8-NPMc+). In parallel, we generated a similar wild-type NPM trans-genic model (hMRP8-NPM). Interestingly, hMRP8-NPMc+ transgenic mice developed myeloproliferation in bone marrow and spleen, whereas nontransgenic littermates and hMRP8-NPM transgenic mice remained disease free. These findings provide the first in vivo evidence indicating that NPMc+ confers a proliferative advantage in the myeloid lineage. No spontaneous acute myeloid leukemia was found in hMPR8-NPMc+ or hMRP8-NPM mice. This model will also aid in the development of therapeutic regimens that specifically target NPMc+.


Author(s):  
Banban Li ◽  
Ruinan Jia ◽  
Wei Li ◽  
Ying Zhou ◽  
Dongmei Guo ◽  
...  

BackgroundChemoresistance is emerging as a major barrier to successful treatment in acute myeloid leukemia (AML), and bone marrow stromal cells (BMSCs) protect leukemia cells from chemotherapy eventually leading to recurrence. This study was designed to investigate the role of p21-activated kinase 1 (PAK1) in AML progression and chemosensitivity, highlighting the mechanism of stroma-mediated chemoresistance.MethodsThe GEPIA and TCGA datasets were used to analyze the relationship between PAK1 mRNA expression and various clinical parameters of AML patients. Cell proliferation and apoptosis were examined to evaluate the role of PAK1 on chemosensitivity in AML by silencing PAK1 with shRNA or small molecular inhibitor. Human BMSC (HS-5) was utilized to mimic the leukemia bone marrow microenvironment (BMM) in vitro, and co-culture model was established to investigate the role of PAK1 in BMSC-mediated drug resistance.Resultsp21-activated kinase 1 high expression was shown to be associated with shorter overall survival in AML patients. The silence of PAK1 could repress cell proliferation, promote apoptosis, and enhance the sensitivity of AML cells to chemotherapeutic agents. More importantly, BMSCs induced PAK1 up-regulation in AML cells, subsequently activating the ERK1/2 signaling pathway. The effect of BMSC-mediated apoptotic-resistance could be partly reversed by knock down of PAK1.Conclusionp21-activated kinase 1 is a potential prognostic predictor for AML patients. PAK1 may play a pivotal role in mediating BMM-induced drug resistance, representing a novel therapeutic target in AML.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Melat T. Gebru ◽  
Hong-Gang Wang

AbstractAcute myeloid leukemia (AML) is a heterogeneous disease caused by several gene mutations and cytogenetic abnormalities affecting differentiation and proliferation of myeloid lineage cells. FLT3 is a receptor tyrosine kinase commonly overexpressed or mutated, and its mutations are associated with poor prognosis in AML. Although aggressive chemotherapy often followed by hematopoietic stem cell transplant is the current standard of care, the recent approval of FLT3-targeted drugs is revolutionizing AML treatment that had remained unchanged since the 1970s. However, despite the dramatic clinical response to targeted agents, such as FLT3 inhibitors, remission is almost invariably short-lived and ensued by relapse and drug resistance. Hence, there is an urgent need to understand the molecular mechanisms driving drug resistance in order to prevent relapse. In this review, we discuss FLT3 as a target and highlight current understanding of FLT3 inhibitor resistance.


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