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Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell
BACKGROUND: Myelodysplastic syndrome (MDS) is a group of heterogeneous hematopoietic stem cell malignancies with a high risk of transformation into acute myeloid leukemia (AML). Clonal evolutions are significantly associated with transformation to AML. According to a gene expression microarray, atg3...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4938461/ https://www.ncbi.nlm.nih.gov/pubmed/27391105 http://dx.doi.org/10.1371/journal.pone.0158761 |
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author | Zhuang, Lin Ma, Yan Wang, Qian Zhang, Jing Zhu, Chen Zhang, Lu Xu, Xiaoping |
author_facet | Zhuang, Lin Ma, Yan Wang, Qian Zhang, Jing Zhu, Chen Zhang, Lu Xu, Xiaoping |
author_sort | Zhuang, Lin |
collection | PubMed |
description | BACKGROUND: Myelodysplastic syndrome (MDS) is a group of heterogeneous hematopoietic stem cell malignancies with a high risk of transformation into acute myeloid leukemia (AML). Clonal evolutions are significantly associated with transformation to AML. According to a gene expression microarray, atg3 is downregulated in MDS patients progressing to leukemia, but less is known about the function of Atg3 in the survival and death of MSD/AML cells. Moreover, the role of autophagy as a result of bortezomib treatment is controversial. The current study was designed to investigate the function of Atg3 in SKM-1 cells and to study the effect of Atg3 on cell viability and cell death following bortezomib treatment. METHODS: Four leukemia cell lines (SKM-1, THP-1, NB4 and K562) and two healthy patients’ bone marrow cells were analyzed for Atg3 expression via qRT-PCR and Western blotting analysis. The role of Atg3 in SKM-1 cell survival and cell death was analyzed by CCK-8 assay, trypan blue exclusion assay, DAPI staining and Annexin V/PI dual staining with or without bortezomib treatment. Western blotting analysis was used to detect proteins in autophagic and caspase signaling pathways. Electron microscopy was used to observe ultrastructural changes after Atg3 overexpression. RESULTS: Downregulation of Atg3 expression was detected in four leukemia cell lines compared with healthy bone marrow cells. Atg3 mRNA was significantly decreased in MDS patients’ bone marrow cells. Overexpression of Atg3 in SKM-1 cells resulted in AKT-mTOR-dependent autophagy, a significant reduction in cell proliferation and increased cell death, which could be overcome by the autophagy inhibitor 3-MA. SKM-1 cells overexpressing Atg3 were hypersensitive to bortezomib treatment at different concentrations via autophagic cell death and enhanced sensitivity to apoptosis in the SKM-1 cell line. Following treatment with 3-MA, the sensitivity of Atg3-overexpressing cells to bortezomib treatment was reduced. Atg3 knockdown blocked cell growth inhibition and cell death induced by bortezomib. CONCLUSION: Our preliminary study of Atg3 in the high-risk MDS cell line suggests that Atg3 might be possibly a critical regulator of autophagic cell death and a gene target for therapeutic interventions in MDS. |
format | Online Article Text |
id | pubmed-4938461 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-49384612016-07-22 Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell Zhuang, Lin Ma, Yan Wang, Qian Zhang, Jing Zhu, Chen Zhang, Lu Xu, Xiaoping PLoS One Research Article BACKGROUND: Myelodysplastic syndrome (MDS) is a group of heterogeneous hematopoietic stem cell malignancies with a high risk of transformation into acute myeloid leukemia (AML). Clonal evolutions are significantly associated with transformation to AML. According to a gene expression microarray, atg3 is downregulated in MDS patients progressing to leukemia, but less is known about the function of Atg3 in the survival and death of MSD/AML cells. Moreover, the role of autophagy as a result of bortezomib treatment is controversial. The current study was designed to investigate the function of Atg3 in SKM-1 cells and to study the effect of Atg3 on cell viability and cell death following bortezomib treatment. METHODS: Four leukemia cell lines (SKM-1, THP-1, NB4 and K562) and two healthy patients’ bone marrow cells were analyzed for Atg3 expression via qRT-PCR and Western blotting analysis. The role of Atg3 in SKM-1 cell survival and cell death was analyzed by CCK-8 assay, trypan blue exclusion assay, DAPI staining and Annexin V/PI dual staining with or without bortezomib treatment. Western blotting analysis was used to detect proteins in autophagic and caspase signaling pathways. Electron microscopy was used to observe ultrastructural changes after Atg3 overexpression. RESULTS: Downregulation of Atg3 expression was detected in four leukemia cell lines compared with healthy bone marrow cells. Atg3 mRNA was significantly decreased in MDS patients’ bone marrow cells. Overexpression of Atg3 in SKM-1 cells resulted in AKT-mTOR-dependent autophagy, a significant reduction in cell proliferation and increased cell death, which could be overcome by the autophagy inhibitor 3-MA. SKM-1 cells overexpressing Atg3 were hypersensitive to bortezomib treatment at different concentrations via autophagic cell death and enhanced sensitivity to apoptosis in the SKM-1 cell line. Following treatment with 3-MA, the sensitivity of Atg3-overexpressing cells to bortezomib treatment was reduced. Atg3 knockdown blocked cell growth inhibition and cell death induced by bortezomib. CONCLUSION: Our preliminary study of Atg3 in the high-risk MDS cell line suggests that Atg3 might be possibly a critical regulator of autophagic cell death and a gene target for therapeutic interventions in MDS. Public Library of Science 2016-07-08 /pmc/articles/PMC4938461/ /pubmed/27391105 http://dx.doi.org/10.1371/journal.pone.0158761 Text en © 2016 Zhuang et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Zhuang, Lin Ma, Yan Wang, Qian Zhang, Jing Zhu, Chen Zhang, Lu Xu, Xiaoping Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell |
title | Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell |
title_full | Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell |
title_fullStr | Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell |
title_full_unstemmed | Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell |
title_short | Atg3 Overexpression Enhances Bortezomib-Induced Cell Death in SKM-1 Cell |
title_sort | atg3 overexpression enhances bortezomib-induced cell death in skm-1 cell |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4938461/ https://www.ncbi.nlm.nih.gov/pubmed/27391105 http://dx.doi.org/10.1371/journal.pone.0158761 |
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