RIGOSERTIB (RIGO) COMBINED WITH AZACITIDINE (AZA) IN VITRO & CLINICAL: MODULATES EPIGENETIC EVENTS AND OVERCOMES CLINICAL RESISTANCE TO HYPOMETHYLATING AGENTS (HMA) IN MYELODYSPLASTIC SYNDROMES (MDS)
(Abstract release date: 05/19/16)
EHA Library. Silverman L. 06/09/16; 132739; E1190
Dr. Lewis Silverman
Contributions
Contributions
Abstract
Abstract: E1190
Type: Eposter Presentation
Background
MDS is a challenging disease to treat due to intricate complexities at the genetic, molecular and epigenetic levels. Epigenetic based therapy with the HMA, AZA is the standard of care for patients (pts) with MDS with higher-risk disease. Treatment alters the natural history of MDS with increased survival, reduced risk of transformation to AML and improved hematopoiesis. However, all pts ultimately fail treatment due to either primary or secondary resistance. Initial results of an ongoing Phase I/II study of AZA combined with RIGO, an allosteric “ras mimetic” that binds to the Ras Binding Domain impacting pathways including ras, raf and PI3 Kinase, in pts with MDS demonstrated an overall response rate of 77%; and 64% in pts following HMA failure (Navada et al ASH 2015).
Aims
1) To determine the in vitro effects of rigosertib alone and in combination with azacitidine on epigenetic signaling in MDS and AML cell lines and on patient samples treated with the combination in vivo.
Methods
We investigated the in vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) and patient samples on global histone post-translational modifications (PTMs) including including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels
Results
In vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) altered global histone post-translational modifications (PTMs) including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels associated with transcriptional activation or repression in both cell lines, but effects were more pronounced in combination with AZA.Furthermore, Q-PCR studies demonstrated that individual treatment of BW90 and MDS-L with RIGO or sequential treatment with AZA (AZA/RIGO or RIGO/AZA) altered the class I, IIa, IIb, and IV histone deacetylases (HDACs), DNA methyl transferases (DNMT1, 3a and 3b) and chromatin remodeler (KDM2a, SET1, JMJD3 and LRWD1) transcript marks in cellular context suggesting that RIGO potentially acts as a chromatin modifying agent (CMA), in both cell lines. Treatment with RIGO either alone or combined with AZA differentially governed cellular proliferation, cell cycle arrest, apoptosis, histone PTMs, altered expression of cell cycle related proteins, and inactivation of the PI3/AKT signaling pathway in a cell specific manner. Similar effects were seen on patient samples.We further investigated the in vivo effects of RIGO combined with AZA on pt bone marrow samples obtained prior to and after one cycle of RIGO and AZA. Interestingly, the histone PTMs, HDACs and chromatin remodelers were significantly altered in the pts BM with increased apoptosis after AZA/RIGO treatment.
Conclusion
RIGO combined with AZA can govern epigenetic mechanisms and overcome clinical resistance to AZA in MDS pts. RIGO potentially functions as a CMA, in combination with AZA and significantly modifies global histone repression and activation marks suggesting that the combination may overcome AZA resistance through epigenetic remodeling of chromatin structure. Additional studies are underway.
Session topic: E-poster
Keyword(s): Chromatin structure, Epigenetic, Myeloid malignancies
Type: Eposter Presentation
Background
MDS is a challenging disease to treat due to intricate complexities at the genetic, molecular and epigenetic levels. Epigenetic based therapy with the HMA, AZA is the standard of care for patients (pts) with MDS with higher-risk disease. Treatment alters the natural history of MDS with increased survival, reduced risk of transformation to AML and improved hematopoiesis. However, all pts ultimately fail treatment due to either primary or secondary resistance. Initial results of an ongoing Phase I/II study of AZA combined with RIGO, an allosteric “ras mimetic” that binds to the Ras Binding Domain impacting pathways including ras, raf and PI3 Kinase, in pts with MDS demonstrated an overall response rate of 77%; and 64% in pts following HMA failure (Navada et al ASH 2015).
Aims
1) To determine the in vitro effects of rigosertib alone and in combination with azacitidine on epigenetic signaling in MDS and AML cell lines and on patient samples treated with the combination in vivo.
Methods
We investigated the in vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) and patient samples on global histone post-translational modifications (PTMs) including including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels
Results
In vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) altered global histone post-translational modifications (PTMs) including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels associated with transcriptional activation or repression in both cell lines, but effects were more pronounced in combination with AZA.Furthermore, Q-PCR studies demonstrated that individual treatment of BW90 and MDS-L with RIGO or sequential treatment with AZA (AZA/RIGO or RIGO/AZA) altered the class I, IIa, IIb, and IV histone deacetylases (HDACs), DNA methyl transferases (DNMT1, 3a and 3b) and chromatin remodeler (KDM2a, SET1, JMJD3 and LRWD1) transcript marks in cellular context suggesting that RIGO potentially acts as a chromatin modifying agent (CMA), in both cell lines. Treatment with RIGO either alone or combined with AZA differentially governed cellular proliferation, cell cycle arrest, apoptosis, histone PTMs, altered expression of cell cycle related proteins, and inactivation of the PI3/AKT signaling pathway in a cell specific manner. Similar effects were seen on patient samples.We further investigated the in vivo effects of RIGO combined with AZA on pt bone marrow samples obtained prior to and after one cycle of RIGO and AZA. Interestingly, the histone PTMs, HDACs and chromatin remodelers were significantly altered in the pts BM with increased apoptosis after AZA/RIGO treatment.
Conclusion
RIGO combined with AZA can govern epigenetic mechanisms and overcome clinical resistance to AZA in MDS pts. RIGO potentially functions as a CMA, in combination with AZA and significantly modifies global histone repression and activation marks suggesting that the combination may overcome AZA resistance through epigenetic remodeling of chromatin structure. Additional studies are underway.
Session topic: E-poster
Keyword(s): Chromatin structure, Epigenetic, Myeloid malignancies
Abstract: E1190
Type: Eposter Presentation
Background
MDS is a challenging disease to treat due to intricate complexities at the genetic, molecular and epigenetic levels. Epigenetic based therapy with the HMA, AZA is the standard of care for patients (pts) with MDS with higher-risk disease. Treatment alters the natural history of MDS with increased survival, reduced risk of transformation to AML and improved hematopoiesis. However, all pts ultimately fail treatment due to either primary or secondary resistance. Initial results of an ongoing Phase I/II study of AZA combined with RIGO, an allosteric “ras mimetic” that binds to the Ras Binding Domain impacting pathways including ras, raf and PI3 Kinase, in pts with MDS demonstrated an overall response rate of 77%; and 64% in pts following HMA failure (Navada et al ASH 2015).
Aims
1) To determine the in vitro effects of rigosertib alone and in combination with azacitidine on epigenetic signaling in MDS and AML cell lines and on patient samples treated with the combination in vivo.
Methods
We investigated the in vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) and patient samples on global histone post-translational modifications (PTMs) including including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels
Results
In vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) altered global histone post-translational modifications (PTMs) including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels associated with transcriptional activation or repression in both cell lines, but effects were more pronounced in combination with AZA.Furthermore, Q-PCR studies demonstrated that individual treatment of BW90 and MDS-L with RIGO or sequential treatment with AZA (AZA/RIGO or RIGO/AZA) altered the class I, IIa, IIb, and IV histone deacetylases (HDACs), DNA methyl transferases (DNMT1, 3a and 3b) and chromatin remodeler (KDM2a, SET1, JMJD3 and LRWD1) transcript marks in cellular context suggesting that RIGO potentially acts as a chromatin modifying agent (CMA), in both cell lines. Treatment with RIGO either alone or combined with AZA differentially governed cellular proliferation, cell cycle arrest, apoptosis, histone PTMs, altered expression of cell cycle related proteins, and inactivation of the PI3/AKT signaling pathway in a cell specific manner. Similar effects were seen on patient samples.We further investigated the in vivo effects of RIGO combined with AZA on pt bone marrow samples obtained prior to and after one cycle of RIGO and AZA. Interestingly, the histone PTMs, HDACs and chromatin remodelers were significantly altered in the pts BM with increased apoptosis after AZA/RIGO treatment.
Conclusion
RIGO combined with AZA can govern epigenetic mechanisms and overcome clinical resistance to AZA in MDS pts. RIGO potentially functions as a CMA, in combination with AZA and significantly modifies global histone repression and activation marks suggesting that the combination may overcome AZA resistance through epigenetic remodeling of chromatin structure. Additional studies are underway.
Session topic: E-poster
Keyword(s): Chromatin structure, Epigenetic, Myeloid malignancies
Type: Eposter Presentation
Background
MDS is a challenging disease to treat due to intricate complexities at the genetic, molecular and epigenetic levels. Epigenetic based therapy with the HMA, AZA is the standard of care for patients (pts) with MDS with higher-risk disease. Treatment alters the natural history of MDS with increased survival, reduced risk of transformation to AML and improved hematopoiesis. However, all pts ultimately fail treatment due to either primary or secondary resistance. Initial results of an ongoing Phase I/II study of AZA combined with RIGO, an allosteric “ras mimetic” that binds to the Ras Binding Domain impacting pathways including ras, raf and PI3 Kinase, in pts with MDS demonstrated an overall response rate of 77%; and 64% in pts following HMA failure (Navada et al ASH 2015).
Aims
1) To determine the in vitro effects of rigosertib alone and in combination with azacitidine on epigenetic signaling in MDS and AML cell lines and on patient samples treated with the combination in vivo.
Methods
We investigated the in vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) and patient samples on global histone post-translational modifications (PTMs) including including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels
Results
In vitro effects of RIGO alone or in combination on two cell lines: AML (BW90), MDS (MDS-L) altered global histone post-translational modifications (PTMs) including methylation (H3K4me3, H3K4me2, H3K27me3, and H3K27me2) and acetylation (H3K9ac, & H3K18ac) levels associated with transcriptional activation or repression in both cell lines, but effects were more pronounced in combination with AZA.Furthermore, Q-PCR studies demonstrated that individual treatment of BW90 and MDS-L with RIGO or sequential treatment with AZA (AZA/RIGO or RIGO/AZA) altered the class I, IIa, IIb, and IV histone deacetylases (HDACs), DNA methyl transferases (DNMT1, 3a and 3b) and chromatin remodeler (KDM2a, SET1, JMJD3 and LRWD1) transcript marks in cellular context suggesting that RIGO potentially acts as a chromatin modifying agent (CMA), in both cell lines. Treatment with RIGO either alone or combined with AZA differentially governed cellular proliferation, cell cycle arrest, apoptosis, histone PTMs, altered expression of cell cycle related proteins, and inactivation of the PI3/AKT signaling pathway in a cell specific manner. Similar effects were seen on patient samples.We further investigated the in vivo effects of RIGO combined with AZA on pt bone marrow samples obtained prior to and after one cycle of RIGO and AZA. Interestingly, the histone PTMs, HDACs and chromatin remodelers were significantly altered in the pts BM with increased apoptosis after AZA/RIGO treatment.
Conclusion
RIGO combined with AZA can govern epigenetic mechanisms and overcome clinical resistance to AZA in MDS pts. RIGO potentially functions as a CMA, in combination with AZA and significantly modifies global histone repression and activation marks suggesting that the combination may overcome AZA resistance through epigenetic remodeling of chromatin structure. Additional studies are underway.
Session topic: E-poster
Keyword(s): Chromatin structure, Epigenetic, Myeloid malignancies
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