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Wang M, Kaiser A, Bieging-Rolett K, Brady C, Attardi L. Abstract 3403: Leveraging a p53 “super-tumor suppressor” to understand mechanisms of lung adenocarcinoma regression. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-3403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Lung cancer is the leading cause of cancer deaths worldwide, and lung adenocarcinoma (LUAD) comprises the majority of lung cancer cases. Inactivation of the TP53 tumor suppressor gene, which encodes the p53 transcription factor, is observed in ~50% of human LUADs and is associated with poor prognosis and therapeutic responses. Hence, pharmacological restoration of p53 is an appealing strategy for LUAD treatment. Previous studies have demonstrated that p53 reactivation in mouse LUAD models leads to tumor regression. Here, we seek to understand the molecular mechanisms through which p53 restoration promotes tumor regression. To this end, we sought to better understand the transcriptional programs underlying tumor regression by leveraging an allelic series of transcriptional activation domain (TAD) mutants. We generated mouse models of LUAD initiated by oncogenic Kras and loss of p53, followed by reactivation of wild-type p53 or p53 TAD mutants, including the TAD1 (p5325,26), TAD2 (p5353,54), and TAD1/2 (p5325,26,53,54) mutants. We find that restoration of wild-type p53 induces significant regression of established tumors. Interestingly, we find that restoration of the p5353,54 mutant induces tumor regression even more potently than wild-type p53, reminiscent of our previous findings showing this mutant is a “super” tumor suppressor in pancreatic cancer. In contrast, the transcriptionally-dead TAD1/2 mutant, p5325,26,53,54, is unable to drive tumor regression. To understand the basis of tumor suppression, we are currently analyzing antiproliferative cellular responses in tumors, including cell cycle arrest, apoptosis, autophagy and differentiation. We have also developed a complementary in vitro system to further explore the molecular mechanisms of p53 action in LUAD regression. RNA-sequencing analysis in this system has revealed transcriptional programs underlying the enhanced tumor regression with the p5353,54 mutant. Collectively, these findings have illuminated the individual contributions of each p53 TAD to LUAD regression. In particular, elucidating the mechanisms by which the “super” tumor suppressor p5353,54 mutant induces tumor regression will provide great insight for developing therapeutic strategies to restore and amplify p53 function.
Citation Format: Mengxiong Wang, Alyssa Kaiser, Kathryn Bieging-Rolett, Colleen Brady, Laura Attardi. Leveraging a p53 “super-tumor suppressor” to understand mechanisms of lung adenocarcinoma regression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3403.
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Affiliation(s)
| | - Alyssa Kaiser
- 1Stanford University School of Medicine, Stanford, CA
| | | | - Colleen Brady
- 1Stanford University School of Medicine, Stanford, CA
| | - Laura Attardi
- 1Stanford University School of Medicine, Stanford, CA
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Tameire F, Wojnarowicz P, Dudgeon C, Fujisawa S, Huang S, Reilly OB, Collette N, Drees J, Bieging-Rolett K, Kangas TO, Zhang W, Fumagalli M, Dewji I, Li Y, Chan ASH, Qiu X, Harrison B, LaCayo A, Cordova RA, Staschke KA, Rigby AC, Ramurthy S, Lightcap ES, Surguladze D, Bose N. Abstract 6231: Activation of GCN2 by HC-7366 results in significant antitumor efficacy as monotherapy and in combination with multiple standard of care agents in various solid cancer models. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-6231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
The integrated stress response (ISR) is an adaptive signaling pathway that cells utilize to respond to a wide range of extrinsic and intrinsic stresses, which are important for tumorigenesis. Activation of ISR is suggested to play a dual role in cell fate decisions. While the ISR promotes survival, prolonged activation of ISR induces apoptosis. We are developing HC-7366, a first-in-class, first-in-human GCN2 activator, and are currently evaluating it in a phase 1 clinical trial in solid tumors (NCT05121948). In this study, we present the characterization of the antitumor effects of HC-7366 in solid tumors.
In vivo efficacy studies using HC-7366 montherapy showed significant tumor growth inhibition (TGI%) in preclinical cancer models of colorectal (78-95%), head and neck (33% regression), sarcoma (80%) and prostate (65%). HC-7366 activated the ISR in tumors from treated mice as evidenced by induction of the ATF4 target genes ASNS and PSAT1. Additionally, HC-7366 induced the proapoptotic protein PUMA and reduced HIF1⍺ and HIF2⍺ levels. Furthermore, HC-7366 showed significant benefit in colorectal models when combined with DC101 (anti-VEGFR2 antibody), 5-fluorouracil (chemotherapy), alpelisib (PI3Kα inhibitor), or trametinib (MEK1/2 inhibitor). Using GCN2 CRISPR-knockout cells, we confirmed that the HC-7366 mediated reduction of cell growth and induction of ISR markers was dependent on GCN2. We performed multi-omics analyses to further understand the mechanism of action. Metabolomics analysis of tumors treated with HC-7366 revealed that HC-7366 altered several metabolites involved in amino acid metabolism, oxidative stress, the urea cycle, and pyrimidine biosynthesis. Additionally, proteomics analysis showed that HC-7366 significantly reduced proteins involved in oxidative phosphorylation. Analysis of the transcriptome in tumors from treated mice demonstrated that HC-7366 reduced the activity of HIF and E2F1-driven transcription, including expression of metaphase-anaphase transition genes, consistent with decreased Ki67 staining in tumors. ATF4 and JUN transcriptional activity was enhanced with HC-7366 treatment consistent with activation of ISR. Collectively, our in vitro and in vivo results demonstrate that HC-7366 is a potent GCN2 activator with strong antitumor activity across multiple solid tumor models as a monotherapy or in combination with standard of care agents.
Citation Format: Feven Tameire, Paulina Wojnarowicz, Crissy Dudgeon, Sho Fujisawa, Sharon Huang, Owen B. Reilly, Nicholas Collette, Jeremy Drees, Kathryn Bieging-Rolett, Takashi O. Kangas, Weiyu Zhang, Maria Fumagalli, Iman Dewji, Yunfang Li, Anissa SH Chan, Xiaohong Qiu, Ben Harrison, Ashley LaCayo, Ricardo A. Cordova, Kirk A. Staschke, Alan C. Rigby, Savithri Ramurthy, Eric S. Lightcap, David Surguladze, Nandita Bose. Activation of GCN2 by HC-7366 results in significant antitumor efficacy as monotherapy and in combination with multiple standard of care agents in various solid cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6231.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ricardo A. Cordova
- 2Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, IN
| | - Kirk A. Staschke
- 2Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, IN
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Valente LJ, Tarangelo A, Li AM, Naciri M, Raj N, Boutelle AM, Li Y, Mello SS, Bieging-Rolett K, DeBerardinis RJ, Ye J, Dixon SJ, Attardi LD. p53 deficiency triggers dysregulation of diverse cellular processes in physiological oxygen. J Cell Biol 2021; 219:152074. [PMID: 32886745 PMCID: PMC7594498 DOI: 10.1083/jcb.201908212] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 06/17/2020] [Accepted: 07/28/2020] [Indexed: 12/20/2022] Open
Abstract
The mechanisms by which TP53, the most frequently mutated gene in human cancer, suppresses tumorigenesis remain unclear. p53 modulates various cellular processes, such as apoptosis and proliferation, which has led to distinct cellular mechanisms being proposed for p53-mediated tumor suppression in different contexts. Here, we asked whether during tumor suppression p53 might instead regulate a wide range of cellular processes. Analysis of mouse and human oncogene-expressing wild-type and p53-deficient cells in physiological oxygen conditions revealed that p53 loss concurrently impacts numerous distinct cellular processes, including apoptosis, genome stabilization, DNA repair, metabolism, migration, and invasion. Notably, some phenotypes were uncovered only in physiological oxygen. Transcriptomic analysis in this setting highlighted underappreciated functions modulated by p53, including actin dynamics. Collectively, these results suggest that p53 simultaneously governs diverse cellular processes during transformation suppression, an aspect of p53 function that would provide a clear rationale for its frequent inactivation in human cancer.
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Affiliation(s)
- Liz J Valente
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Amy Tarangelo
- Department of Biology, Stanford University, Stanford, CA
| | - Albert Mao Li
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Marwan Naciri
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA.,École Normale Supérieure de Lyon, Université Claude Bernard Lyon I, Université de Lyon, Lyon, France
| | - Nitin Raj
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Anthony M Boutelle
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Yang Li
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Stephano Spano Mello
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA.,Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY
| | - Kathryn Bieging-Rolett
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jiangbin Ye
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
| | - Scott J Dixon
- Department of Biology, Stanford University, Stanford, CA
| | - Laura D Attardi
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA.,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA
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Mello SS, Bieging-Rolett K, Kaiser A, Valente EJ, Raj N, McClendon J, Flowers BM, Morgens DW, Bassik MC, Attardi LD. Abstract IA07: Deconstructing p53 pathways in tumor suppression. Cancer Res 2018. [DOI: 10.1158/1538-7445.mousemodels17-ia07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The p53 transcription factor is a critical tumor suppressor in humans and mice. Despite this essential function, the molecular pathways through which p53 acts in tumor suppression remain enigmatic. To define the transcriptional programs through which p53 suppresses carcinogenesis, we have taken combined mouse genetic and genomic approaches. We previously generated a panel of p53 knock-in mouse strains expressing mutants in the first (p5325,26), second (p5353,54), or both (p5325,26,53,54) of two amino-terminal transcriptional activation domains (TADs). In terms of transcriptional activity, we have discovered that p5325,26 is severely impaired for transactivation of the majority of canonical p53 target genes (e.g. p21, Puma, Noxa), but retains the ability to activate a set of primarily novel p53 target genes, while p5325,26,53,54 lacks transactivation activity altogether. The p5353,54 mutant, in contrast, is uncompromised for transactivation of p53 target genes. The p5325,26,53,54 mutant is completely defective in tumor suppression, underscoring the importance of transcriptional activation for p53-mediated tumor suppression. Intriguingly, the p5325,26 mutant retains full activity in suppressing a variety of cancers, indicating that efficient transactivation of most canonical p53 target genes is dispensable for tumor suppression. As p5325,26 activates only a subset of p53-inducible genes, yet retains tumor-suppressor activity, it has helped pinpoint a small set of novel, direct p53-inducible tumor suppression-associated target genes (TSAGs) whose functions we are currently interrogating through genetic screens. Additionally, we have made the surprising discovery that the p5353,54 mutant suppresses pancreatic cancer more efficiently than wild-type p53, and that this capacity correlates with the ability of p5353,54 to hyperactivate a subset of p53 target genes. Indeed, our analysis of these genes has uncovered Ptpn14, a direct p53 target gene critical for mediating p53 function in suppressing pancreatic cancer cell growth. Ptpn14 encodes a protein tyrosine phosphatase that negatively regulates the oncoprotein Yap in both human and mouse cells. These studies thus reveal a p53-Ptpn14-Yap axis in pancreatic cancer. Together, these strategies will help to elaborate the transcriptional networks fundamental for p53 function in tumor suppression.
Citation Format: Stephano Spano Mello, Kathryn Bieging-Rolett, Alyssa Kaiser, Elizabeth Joy Valente, Nitin Raj, Jacob McClendon, Brittany Maria Flowers, David Warren Morgens, Michael Cory Bassik, Laura Donatella Attardi. Deconstructing p53 pathways in tumor suppression [abstract]. In: Proceedings of the AACR Special Conference: Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond; 2017 Sep 24-27; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(10 Suppl):Abstract nr IA07.
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Mello SS, Sinow C, Raj N, Mazur PK, Bieging-Rolett K, Broz DK, Imam JFC, Vogel H, Wood LD, Sage J, Hirose T, Nakagawa S, Rinn J, Attardi LD. Neat1 is a p53-inducible lincRNA essential for transformation suppression. Genes Dev 2017; 31:1095-1108. [PMID: 28698299 PMCID: PMC5538433 DOI: 10.1101/gad.284661.116] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [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: 05/25/2016] [Accepted: 05/26/2017] [Indexed: 12/12/2022]
Abstract
Mello et al. identify Neat1, a ncRNA constituent of paraspeckles, as a p53 target gene that plays a crucial role in suppressing transformation in response to oncogenic signals. The p53 gene is mutated in over half of all cancers, reflecting its critical role as a tumor suppressor. Although p53 is a transcriptional activator that induces myriad target genes, those p53-inducible genes most critical for tumor suppression remain elusive. Here, we leveraged p53 ChIP-seq (chromatin immunoprecipitation [ChIP] combined with high-throughput sequencing) and RNA-seq (RNA sequencing) data sets to identify new p53 target genes, focusing on the noncoding genome. We identify Neat1, a noncoding RNA (ncRNA) constituent of paraspeckles, as a p53 target gene broadly induced by mouse and human p53 in different cell types and by diverse stress signals. Using fibroblasts derived from Neat1−/− mice, we examined the functional role of Neat1 in the p53 pathway. We found that Neat1 is dispensable for cell cycle arrest and apoptosis in response to genotoxic stress. In sharp contrast, Neat1 plays a crucial role in suppressing transformation in response to oncogenic signals. Neat1 deficiency enhances transformation in oncogene-expressing fibroblasts and promotes the development of premalignant pancreatic intraepithelial neoplasias (PanINs) and cystic lesions in KrasG12D-expressing mice. Neat1 loss provokes global changes in gene expression, suggesting a mechanism by which its deficiency promotes neoplasia. Collectively, these findings identify Neat1 as a p53-regulated large intergenic ncRNA (lincRNA) with a key role in suppressing transformation and cancer initiation, providing fundamental new insight into p53-mediated tumor suppression.
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Affiliation(s)
- Stephano S Mello
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Carolyn Sinow
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Nitin Raj
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Pawel K Mazur
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Kathryn Bieging-Rolett
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Daniela Kenzelmann Broz
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Jamie F Conklin Imam
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Laura D Wood
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
| | - Julien Sage
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Tetsuro Hirose
- Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | - Shinichi Nakagawa
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - John Rinn
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Laura D Attardi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, California 94305, USA
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Attardi LD, Mello SS, Valente EJ, Mazur PK, Raj N, Bieging-Rolett K, Vogel H. Abstract PR07: Deconstructing p53 transcriptional networks in pancreatic cancer suppression. Cancer Res 2016. [DOI: 10.1158/1538-7445.panca16-pr07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The p53 transcription factor is mutated in the majority of human pancreatic cancers, underscoring its critical role in suppressing pancreatic cancer development. Although p53 can restrain neoplastic cell expansion by inducing cell-cycle arrest or apoptosis in response to diverse stress signals, the molecular pathways through which p53 acts in tumor suppression remain largely elusive. To define the transcriptional networks underlying p53 tumor suppressor function, we have used mouse genetic and genomic approaches. We generated a set of p53 knock-in mouse strains expressing mutants in the first (p53 25,26), second (p5353,54), or both (p5325,26,53,54) of two transcriptional activation domains (TADs). Using a combination of ChIP-sequencing and expression profiling on cells expressing these mutants, we have been able to define a limited list of direct p53 target genes whose expression is tightly correlated with tumor suppression. Specifically, we found that p5325,26 is severely compromised for transactivation of most classical p53 target genes (e.g. p21, Puma), but retains the ability to activate a subset of p53 target genes, while p5325,26,53,54 lacks transactivation activity completely. The p5325,26,53,54 mutant is completely inactive in tumor suppression, highlighting the importance of transactivation for p53-mediated tumor suppression. Interestingly, however, p5325,26 retains full activity in suppressing various cancers, including pancreatic cancer, indicating that efficient transactivation of most canonical p53 targets is dispensable for tumor suppression. As p5325,26 activates only a subset of p53-dependent genes, yet retains tumor suppressor activity, it has helped pinpoint a small set of novel, direct p53-inducible tumor suppression-associated genes (TSAGs) whose functions we are currently interrogating through genetic screens. In addition, we have made the surprising discovery that the p5353,54 mutant suppresses pancreatic cancer more effectively than wild-type p53, and that this capacity correlates with the ability of p5353,54 to hyperactivate a subset of p53 target genes. Indeed, our analysis of these genes has unveiled p53 targets critical for mediating p53 function in suppressing mouse and human pancreatic cancer cell growth, including a protein tyrosine phosphatase that negatively regulates Yap signaling. Collectively, these approaches will delineate the transcriptional networks fundamental for p53 function in tumor suppression, an approach that will ultimately facilitate the design of novel therapies for pancreatic cancers with p53 mutation.
Citation Format: Laura D. Attardi, Stephano Spano Mello, Elizabeth J. Valente, Pawel K. Mazur, Nitin Raj, Kathryn Bieging-Rolett, Hannes Vogel.{Authors}. Deconstructing p53 transcriptional networks in pancreatic cancer suppression. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr PR07.
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