1
|
Bansal N, Bosch A, Leibovitch B, Pereira L, Cubedo E, Yu J, Pierzchalski K, Jones JW, Fishel M, Kane M, Zelent A, Waxman S, Farias E. Blocking the PAH2 domain of Sin3A inhibits tumorigenesis and confers retinoid sensitivity in triple negative breast cancer. Oncotarget 2018; 7:43689-43702. [PMID: 27286261 PMCID: PMC5190053 DOI: 10.18632/oncotarget.9905] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/05/2016] [Indexed: 12/24/2022] Open
Abstract
Triple negative breast cancer (TNBC) frequently relapses locally, regionally or as systemic metastases. Development of targeted therapy that offers significant survival benefit in TNBC is an unmet clinical need. We have previously reported that blocking interactions between PAH2 domain of chromatin regulator Sin3A and the Sin3 interaction domain (SID) containing proteins by SID decoys result in EMT reversal, and re-expression of genes associated with differentiation. Here we report a novel and therapeutically relevant combinatorial use of SID decoys. SID decoys activate RARα/β pathways that are enhanced in combination with RARα-selective agonist AM80 to induce morphogenesis and inhibit tumorsphere formation. These findings correlate with inhibition of mammary hyperplasia and a significant increase in tumor-free survival in MMTV-Myc oncomice treated with a small molecule mimetic of SID (C16). Further, in two well-established mouse TNBC models we show that treatment with C16-AM80 combination has marked anti-tumor effects, prevents lung metastases and seeding of tumor cells to bone marrow. This correlated to a remarkable 100% increase in disease-free survival with a possibility of "cure" in mice bearing a TNBC-like tumor. Targeting Sin3A by C16 alone or in combination with AM80 may thus be a promising adjuvant therapy for treating or preventing metastatic TNBC.
Collapse
Affiliation(s)
- Nidhi Bansal
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Almudena Bosch
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Boris Leibovitch
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lutecia Pereira
- Division of Hemato-Oncology, Department of Medicine, Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Elena Cubedo
- Division of Hemato-Oncology, Department of Medicine, Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Jianshi Yu
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, USA
| | - Keely Pierzchalski
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, USA
| | - Jace W Jones
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, USA
| | - Melissa Fishel
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Maureen Kane
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, USA
| | - Arthur Zelent
- Division of Hemato-Oncology, Department of Medicine, Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Samuel Waxman
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eduardo Farias
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| |
Collapse
|
2
|
Farias EF, Ong DE, Ghyselinck NB, Nakajo S, Kuppumbatti YS, Mira y Lopez R. Cellular retinol-binding protein I, a regulator of breast epithelial retinoic acid receptor activity, cell differentiation, and tumorigenicity. J Natl Cancer Inst 2005; 97:21-9. [PMID: 15632377 DOI: 10.1093/jnci/dji004] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Retinoic acid receptor (RAR) activation induces cell differentiation and may antagonize cancer progression. Cellular retinol-binding protein I (CRBP-I) functions in retinol storage and its expression is lower in human cancers than in normal cells. We hypothesized that retinol storage might be linked to RAR activation and thus that lowered CRBP-I function might impair RAR activity and cell differentiation. METHODS Sarcoma virus 40-immortalized human mammary epithelial cells (MTSV1-7) devoid of CRBP-I were transfected with wild-type CRBP-I or CRBP-I point mutants with low RA binding affinity. The subcellular localization of CRBP-I was investigated in these cells and in wild-type or CRBP-I null mouse mammary epithelial cells (MECs), using indirect immunofluorescence and sucrose gradient fractionation. RAR activity was assessed using reporter gene assays. Acinar differentiation and in vivo tumor growth were assessed in reconstituted basement membrane and athymic mice, respectively. RESULTS In cells expressing wild-type CRBP-I but not the CRBP-I mutants, CRBP-I was found mainly in lipid droplets, the retinol storage organelle, and this localization was associated with promotion of retinol storage by wild-type CRBP-I only. RAR activity was higher and acinar differentiation was observed in cells expressing wild-type but not mutant CRBP-I. RAR antagonist treatment blocked and chronic RA treatment mimicked, the CRBP-I induction of cell differentiation. Finally, CRBP-I suppressed tumorigenicity in athymic mice. CONCLUSIONS Physiologic RAR activation is dependent on CRBP-I-mediated retinol storage, and CRBP-I downregulation chronically compromises RAR activity, leading to loss of cell differentiation and tumor progression.
Collapse
Affiliation(s)
- Eduardo F Farias
- Department of Medicine, Mount Sinai School of Medicine, Annenberg Bldg., Rm 24-74, One Gustave L. Levy Place, New York, NY 10029, USA.
| | | | | | | | | | | |
Collapse
|
3
|
Richards B, Karpilow J, Dunn C, Peterson I, Maxfield A, Zharkikh L, Abedi M, Hurlburt A, Hardman J, Hsu F, Li W, Rebentisch M, Sandrock R, Sandrock T, Kamb A, Teng DHF. Genetic selection for modulators of a retinoic-acid-responsive reporter in human cells. Genetics 2003; 163:1047-60. [PMID: 12663543 PMCID: PMC1462493 DOI: 10.1093/genetics/163.3.1047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We used a genetic screening methodology, a human cell line bearing a retinoic-acid-responsive enhanced GFP reporter, and a flow sorter to recover dominant modulators of reporter expression. Four inducers and three suppressors that were fused to the C terminus of a protein scaffold for stability were isolated and their mechanisms of action studied. Mutagenesis experiments indicated that six of these dominant agents exerted their effects at the protein level. The single cDNA coding fragment that was isolated comprised the central 64-amino-acid section of human cyclophilin B, which contained its peptidyl-prolyl isomerase domain; this cyclophilin fragment repressed expression of the retinoic-acid-responsive reporter. The remaining clones encoded peptides shorter than 30 amino acids unrelated to known gene open reading frames. Genetic epistasis studies between the strongest inducer, R3, and a dominant-negative mutant of RARalpha suggest that the two factors function in the same pathway. Transcript microarray analyses suggest that R3 induced a subset of the retinoid-responsive genes in melanoma cells. Finally, yeast two-hybrid assays and co-immunoprecipitation studies of human cell extracts identified PAT1 as a protein that interacts with R3.
Collapse
Affiliation(s)
- Burt Richards
- Deltagen Proteomics, Salt Lake City, Utah 84108, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|