MICRORNA-155 AND MICRORNA-708 ARE OPPOSING MODULATORS OF HOXA9 ACTIVITY IN ACUTE MYELOID LEUKEMIA
(Abstract release date: 05/19/16)
EHA Library. Schneider E. 06/10/16; 133161; P173
Dr. Edith Schneider
Contributions
Contributions
Abstract
Abstract: P173
Type: Poster Presentation
Presentation during EHA21: On Friday, June 10, 2016 from 17:15 - 18:45
Location: Poster area (Hall H)
Background
In order to identify microRNAs (miRNA) relevant in acute myeloid leukemia (AML), we profiled global miRNA expression in a murine AML progression model based on Hoxa9 and Meis1 overexpression.
Aims
We found miR-155 and miR-708 as the most significantly upregulated miRNAs in leukemic Hoxa9/Meis1 cells compared to the preleukemic Hoxa9/ctrl cells (both p<0.01). Subsequent analysis of primary AML cases (n=38) comprising various AML subtypes showed significantly elevated levels of miR-155 and miR-708 in all samples compared to total bone marrow from healthy donors, indicating potential oncogenic roles for these miRNAs.We further investigated, in vivo, the role of miR-155 in AML by retroviral overexpression with Hoxa9 in murine bone marrow (mbm) cells followed by syngeneic transplantation. Overexpression of miR-155 in conjunction with Hoxa9 (Hoxa9/miR-155) caused a significantly accelerated onset of a myelomonocytic leukemia (p<0.001), but still a less aggressive course of disease compared to mice transplanted with Hoxa9/Meis1 (p<0.001). In order to assess if miR-155 is dispensable for the onset of AML, we transformed miR-155-/- and miR-155+/+ mbm with Hoxa9/Meis1 followed by syngeneic transplantation. No difference in onset of AML was observed. Further analysis revealed that absence of miR-155 impaired homing of Hoxa9/Meis1 cells but did not impact their proliferation rate, which eventually compensated for impaired engraftment in this AML model.
Methods
We then hypothesized that the combination of miR-155 and miR-708 could further replace the oncogenic potential of Meis1. Therefore, mbm cells were retrovirally transduced with Hoxa9, miR-155 and miR-708 (Hoxa9/miR-155/miR-708) or Hoxa9 and miR-708 (Hoxa9/miR-708) and functionally analyzed in vitro and in vivo. To our surprise, miR-708 abrogated the leukemogenic effect of Hoxa9, alone or in combination with Hoxa9/miR-155 in vivo (p=0.0117, p<0.0001), with little or no engraftment. Transcriptome analysis revealed that miR-155 and miR-708 have opposite effects on Hoxa9-induced transcription.
Results
To further understand why miR-708, a potent tumor suppressor miRNA, is upregulated in the highly aggressive Hoxa9/Meis1 AML cells, we explored the role of miR-708 in leukemia initiating cells (LIC). Hoxa9/Meis1 cell subpopulations enriched for LIC based on c-kit, Mac-1 and Gr-1 expression were FACS-sorted and transplanted into syngeneic mice. The c-kit+Gr-1-Mac-1- cells caused a significantly shorter survival of transplanted mice compared to the other sorted subpopulations (p=0.0072 and p=0.0021, respectively), with the c-kit-Gr-1+Mac-1+ subpopulation resulting in the longest survival. This was mirrored by lower expression of miR-708 in the LIC-enriched c-kit+Gr-1-Mac-1- subpopulation compared to bulk (p=0.032), whereas there was no difference in miR-155 expression. Similar findings were made in human AML samples (n=7) sorted into LIC-enriched subpopulations using CD117, CD34 and CD38. Together, these results highlight the role of miR-708 as an orchestrator of the leukemic hierarchy through its tumor suppressor activity.
Conclusion
In conclusion, we demonstrate for the first time a functional role for miR-155 in homing of AML cells. In addition, we propose as a novel concept where miR-708, a tumor suppressor miRNA, stratifies the leukemic hierarchy.
Session topic: Acute myeloid leukemia - Biology 1
Type: Poster Presentation
Presentation during EHA21: On Friday, June 10, 2016 from 17:15 - 18:45
Location: Poster area (Hall H)
Background
In order to identify microRNAs (miRNA) relevant in acute myeloid leukemia (AML), we profiled global miRNA expression in a murine AML progression model based on Hoxa9 and Meis1 overexpression.
Aims
We found miR-155 and miR-708 as the most significantly upregulated miRNAs in leukemic Hoxa9/Meis1 cells compared to the preleukemic Hoxa9/ctrl cells (both p<0.01). Subsequent analysis of primary AML cases (n=38) comprising various AML subtypes showed significantly elevated levels of miR-155 and miR-708 in all samples compared to total bone marrow from healthy donors, indicating potential oncogenic roles for these miRNAs.We further investigated, in vivo, the role of miR-155 in AML by retroviral overexpression with Hoxa9 in murine bone marrow (mbm) cells followed by syngeneic transplantation. Overexpression of miR-155 in conjunction with Hoxa9 (Hoxa9/miR-155) caused a significantly accelerated onset of a myelomonocytic leukemia (p<0.001), but still a less aggressive course of disease compared to mice transplanted with Hoxa9/Meis1 (p<0.001). In order to assess if miR-155 is dispensable for the onset of AML, we transformed miR-155-/- and miR-155+/+ mbm with Hoxa9/Meis1 followed by syngeneic transplantation. No difference in onset of AML was observed. Further analysis revealed that absence of miR-155 impaired homing of Hoxa9/Meis1 cells but did not impact their proliferation rate, which eventually compensated for impaired engraftment in this AML model.
Methods
We then hypothesized that the combination of miR-155 and miR-708 could further replace the oncogenic potential of Meis1. Therefore, mbm cells were retrovirally transduced with Hoxa9, miR-155 and miR-708 (Hoxa9/miR-155/miR-708) or Hoxa9 and miR-708 (Hoxa9/miR-708) and functionally analyzed in vitro and in vivo. To our surprise, miR-708 abrogated the leukemogenic effect of Hoxa9, alone or in combination with Hoxa9/miR-155 in vivo (p=0.0117, p<0.0001), with little or no engraftment. Transcriptome analysis revealed that miR-155 and miR-708 have opposite effects on Hoxa9-induced transcription.
Results
To further understand why miR-708, a potent tumor suppressor miRNA, is upregulated in the highly aggressive Hoxa9/Meis1 AML cells, we explored the role of miR-708 in leukemia initiating cells (LIC). Hoxa9/Meis1 cell subpopulations enriched for LIC based on c-kit, Mac-1 and Gr-1 expression were FACS-sorted and transplanted into syngeneic mice. The c-kit+Gr-1-Mac-1- cells caused a significantly shorter survival of transplanted mice compared to the other sorted subpopulations (p=0.0072 and p=0.0021, respectively), with the c-kit-Gr-1+Mac-1+ subpopulation resulting in the longest survival. This was mirrored by lower expression of miR-708 in the LIC-enriched c-kit+Gr-1-Mac-1- subpopulation compared to bulk (p=0.032), whereas there was no difference in miR-155 expression. Similar findings were made in human AML samples (n=7) sorted into LIC-enriched subpopulations using CD117, CD34 and CD38. Together, these results highlight the role of miR-708 as an orchestrator of the leukemic hierarchy through its tumor suppressor activity.
Conclusion
In conclusion, we demonstrate for the first time a functional role for miR-155 in homing of AML cells. In addition, we propose as a novel concept where miR-708, a tumor suppressor miRNA, stratifies the leukemic hierarchy.
Session topic: Acute myeloid leukemia - Biology 1
Abstract: P173
Type: Poster Presentation
Presentation during EHA21: On Friday, June 10, 2016 from 17:15 - 18:45
Location: Poster area (Hall H)
Background
In order to identify microRNAs (miRNA) relevant in acute myeloid leukemia (AML), we profiled global miRNA expression in a murine AML progression model based on Hoxa9 and Meis1 overexpression.
Aims
We found miR-155 and miR-708 as the most significantly upregulated miRNAs in leukemic Hoxa9/Meis1 cells compared to the preleukemic Hoxa9/ctrl cells (both p<0.01). Subsequent analysis of primary AML cases (n=38) comprising various AML subtypes showed significantly elevated levels of miR-155 and miR-708 in all samples compared to total bone marrow from healthy donors, indicating potential oncogenic roles for these miRNAs.We further investigated, in vivo, the role of miR-155 in AML by retroviral overexpression with Hoxa9 in murine bone marrow (mbm) cells followed by syngeneic transplantation. Overexpression of miR-155 in conjunction with Hoxa9 (Hoxa9/miR-155) caused a significantly accelerated onset of a myelomonocytic leukemia (p<0.001), but still a less aggressive course of disease compared to mice transplanted with Hoxa9/Meis1 (p<0.001). In order to assess if miR-155 is dispensable for the onset of AML, we transformed miR-155-/- and miR-155+/+ mbm with Hoxa9/Meis1 followed by syngeneic transplantation. No difference in onset of AML was observed. Further analysis revealed that absence of miR-155 impaired homing of Hoxa9/Meis1 cells but did not impact their proliferation rate, which eventually compensated for impaired engraftment in this AML model.
Methods
We then hypothesized that the combination of miR-155 and miR-708 could further replace the oncogenic potential of Meis1. Therefore, mbm cells were retrovirally transduced with Hoxa9, miR-155 and miR-708 (Hoxa9/miR-155/miR-708) or Hoxa9 and miR-708 (Hoxa9/miR-708) and functionally analyzed in vitro and in vivo. To our surprise, miR-708 abrogated the leukemogenic effect of Hoxa9, alone or in combination with Hoxa9/miR-155 in vivo (p=0.0117, p<0.0001), with little or no engraftment. Transcriptome analysis revealed that miR-155 and miR-708 have opposite effects on Hoxa9-induced transcription.
Results
To further understand why miR-708, a potent tumor suppressor miRNA, is upregulated in the highly aggressive Hoxa9/Meis1 AML cells, we explored the role of miR-708 in leukemia initiating cells (LIC). Hoxa9/Meis1 cell subpopulations enriched for LIC based on c-kit, Mac-1 and Gr-1 expression were FACS-sorted and transplanted into syngeneic mice. The c-kit+Gr-1-Mac-1- cells caused a significantly shorter survival of transplanted mice compared to the other sorted subpopulations (p=0.0072 and p=0.0021, respectively), with the c-kit-Gr-1+Mac-1+ subpopulation resulting in the longest survival. This was mirrored by lower expression of miR-708 in the LIC-enriched c-kit+Gr-1-Mac-1- subpopulation compared to bulk (p=0.032), whereas there was no difference in miR-155 expression. Similar findings were made in human AML samples (n=7) sorted into LIC-enriched subpopulations using CD117, CD34 and CD38. Together, these results highlight the role of miR-708 as an orchestrator of the leukemic hierarchy through its tumor suppressor activity.
Conclusion
In conclusion, we demonstrate for the first time a functional role for miR-155 in homing of AML cells. In addition, we propose as a novel concept where miR-708, a tumor suppressor miRNA, stratifies the leukemic hierarchy.
Session topic: Acute myeloid leukemia - Biology 1
Type: Poster Presentation
Presentation during EHA21: On Friday, June 10, 2016 from 17:15 - 18:45
Location: Poster area (Hall H)
Background
In order to identify microRNAs (miRNA) relevant in acute myeloid leukemia (AML), we profiled global miRNA expression in a murine AML progression model based on Hoxa9 and Meis1 overexpression.
Aims
We found miR-155 and miR-708 as the most significantly upregulated miRNAs in leukemic Hoxa9/Meis1 cells compared to the preleukemic Hoxa9/ctrl cells (both p<0.01). Subsequent analysis of primary AML cases (n=38) comprising various AML subtypes showed significantly elevated levels of miR-155 and miR-708 in all samples compared to total bone marrow from healthy donors, indicating potential oncogenic roles for these miRNAs.We further investigated, in vivo, the role of miR-155 in AML by retroviral overexpression with Hoxa9 in murine bone marrow (mbm) cells followed by syngeneic transplantation. Overexpression of miR-155 in conjunction with Hoxa9 (Hoxa9/miR-155) caused a significantly accelerated onset of a myelomonocytic leukemia (p<0.001), but still a less aggressive course of disease compared to mice transplanted with Hoxa9/Meis1 (p<0.001). In order to assess if miR-155 is dispensable for the onset of AML, we transformed miR-155-/- and miR-155+/+ mbm with Hoxa9/Meis1 followed by syngeneic transplantation. No difference in onset of AML was observed. Further analysis revealed that absence of miR-155 impaired homing of Hoxa9/Meis1 cells but did not impact their proliferation rate, which eventually compensated for impaired engraftment in this AML model.
Methods
We then hypothesized that the combination of miR-155 and miR-708 could further replace the oncogenic potential of Meis1. Therefore, mbm cells were retrovirally transduced with Hoxa9, miR-155 and miR-708 (Hoxa9/miR-155/miR-708) or Hoxa9 and miR-708 (Hoxa9/miR-708) and functionally analyzed in vitro and in vivo. To our surprise, miR-708 abrogated the leukemogenic effect of Hoxa9, alone or in combination with Hoxa9/miR-155 in vivo (p=0.0117, p<0.0001), with little or no engraftment. Transcriptome analysis revealed that miR-155 and miR-708 have opposite effects on Hoxa9-induced transcription.
Results
To further understand why miR-708, a potent tumor suppressor miRNA, is upregulated in the highly aggressive Hoxa9/Meis1 AML cells, we explored the role of miR-708 in leukemia initiating cells (LIC). Hoxa9/Meis1 cell subpopulations enriched for LIC based on c-kit, Mac-1 and Gr-1 expression were FACS-sorted and transplanted into syngeneic mice. The c-kit+Gr-1-Mac-1- cells caused a significantly shorter survival of transplanted mice compared to the other sorted subpopulations (p=0.0072 and p=0.0021, respectively), with the c-kit-Gr-1+Mac-1+ subpopulation resulting in the longest survival. This was mirrored by lower expression of miR-708 in the LIC-enriched c-kit+Gr-1-Mac-1- subpopulation compared to bulk (p=0.032), whereas there was no difference in miR-155 expression. Similar findings were made in human AML samples (n=7) sorted into LIC-enriched subpopulations using CD117, CD34 and CD38. Together, these results highlight the role of miR-708 as an orchestrator of the leukemic hierarchy through its tumor suppressor activity.
Conclusion
In conclusion, we demonstrate for the first time a functional role for miR-155 in homing of AML cells. In addition, we propose as a novel concept where miR-708, a tumor suppressor miRNA, stratifies the leukemic hierarchy.
Session topic: Acute myeloid leukemia - Biology 1
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