1
|
GADD45g acts as a novel tumor suppressor and its activation confers new combination regimens for the treatment of AML. Blood 2021; 138:464-479. [PMID: 33945602 DOI: 10.1182/blood.2020008229] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 04/07/2021] [Indexed: 11/20/2022] Open
Abstract
Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy for which there is an unmet need for novel treatment strategies. Here, we characterize the growth arrest and DNA damage-inducible gene gamma (GADD45g) as a novel tumor suppressor in AML. We show that GADD45g is preferentially silenced in AML, especially in AML with FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations and mixed-lineage leukemia (MLL)-rearrangements, and reduced expression of GADD45g is correlated with poor prognosis in AML patients. Upregulation of GADD45g impairs homologous recombination (HR) DNA repair, leading to DNA damage accumulation, and dramatically induces apoptosis, differentiation, growth arrest and increases sensitivity of AML cells to chemotherapeutic drugs, without affecting normal cells. In addition, GADD45g is epigenetically silenced by histone deacetylation in AML, and its expression is further downregulated by oncogenes FLT3-ITD and MLL-AF9 in patients carrying these genetic abnormalities. Combination of histone deacetylase 1/2 inhibitor Romidepsin with FLT3 tyrosine kinase inhibitor AC220 or bromodomain inhibitor JQ1 exert synergistic anti-leukemic effects on FLT3-ITD+ and MLL-AF9+ AML, respectively, by dually activating GADD45g. These findings uncover hitherto unreported evidence for the selective anti-leukemia role of GADD45g and provide novel strategies for the treatment of FLT3-ITD+ and MLL-AF9+ AML.
Collapse
|
2
|
Yang X, Pan Y, Qiu Z, Du Z, Zhang Y, Fa P, Gorityala S, Ma S, Li S, Chen C, Wang H, Xu Y, Yan C, Ruth K, Ma Z, Zhang J. RNF126 as a Biomarker of a Poor Prognosis in Invasive Breast Cancer and CHEK1 Inhibitor Efficacy in Breast Cancer Cells. Clin Cancer Res 2018; 24:1629-1643. [PMID: 29326282 DOI: 10.1158/1078-0432.ccr-17-2242] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/10/2017] [Accepted: 01/05/2018] [Indexed: 01/20/2023]
Abstract
Purpose: (i) To investigate the expression of the E3 ligase, RNF126, in human invasive breast cancer and its links with breast cancer outcomes; and (ii) to test the hypothesis that RNF126 determines the efficacy of inhibitors targeting the cell-cycle checkpoint kinase, CHEK1.Experimental Design: A retrospective analysis by immunohistochemistry (IHC) compared RNF126 staining in 110 invasive breast cancer and 78 paired adjacent normal tissues with clinicopathologic data. Whether RNF126 controls CHEK1 expression was determined by chromatin immunoprecipitation and a CHEK1 promoter driven luciferase reporter. Staining for these two proteins by IHC using tissue microarrays was also conducted. Cell killing/replication stress induced by CHEK1 inhibition was evaluated in cells, with or without RNF126 knockdown, by MTT/colony formation, replication stress biomarker immunostaining and DNA fiber assays.Results: RNF126 protein expression was elevated in breast cancer tissue samples. RNF126 was associated with a poor clinical outcome after multivariate analysis and was an independent predictor. RNF126 promotes CHEK1 transcript expression. Critically, a strong correlation between RNF126 and CHEK1 proteins was identified in breast cancer tissue and cell lines. The inhibition of CHEK1 induced a greater cell killing and a higher level of replication stress in breast cancer cells expressing RNF126 compared to RNF126 depleted cells.Conclusions: RNF126 protein is highly expressed in invasive breast cancer tissue. The high expression of RNF126 is an independent predictor of a poor prognosis in invasive breast cancer and is considered a potential biomarker of a cancer's responsiveness to CHEK1 inhibitors. CHEK1 inhibition targets breast cancer cells expressing higher levels of RNF126 by enhancing replication stress. Clin Cancer Res; 24(7); 1629-43. ©2018 AACR.
Collapse
Affiliation(s)
- Xiaosong Yang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Breast Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - You Pan
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Breast Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhaojun Qiu
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Zhanwen Du
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Yao Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Pengyan Fa
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | | | - Shanhuai Ma
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Shunqiang Li
- Division of Oncology Breast Oncology Section, Washington University Medical School, St. Louis, Missouri
| | - Ceshi Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
| | - Hongbing Wang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland
| | - Yan Xu
- Department of Chemistry, Cleveland State University, Cleveland, Ohio.,Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Chunhong Yan
- Georgia Cancer Center, Augusta University, Augusta, Georgia
| | - Keri Ruth
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio.,Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Zhefu Ma
- Department of Breast Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. .,Department of Breast Surgery & Plastic Surgery, Cancer Hospital of China Medical University, Shenyang, China
| | - Junran Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, Cleveland, Ohio. .,Department of Radiation Oncology, The Ohio State University, Columbus, Ohio
| |
Collapse
|
3
|
Vélez-Cruz R, Manickavinayaham S, Biswas AK, Clary RW, Premkumar T, Cole F, Johnson DG. RB localizes to DNA double-strand breaks and promotes DNA end resection and homologous recombination through the recruitment of BRG1. Genes Dev 2017; 30:2500-2512. [PMID: 27940962 PMCID: PMC5159665 DOI: 10.1101/gad.288282.116] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/03/2016] [Indexed: 11/24/2022]
Abstract
The retinoblastoma (RB) tumor suppressor is recognized as a master regulator that controls entry into the S phase of the cell cycle. Its loss leads to uncontrolled cell proliferation and is a hallmark of cancer. RB works by binding to members of the E2F family of transcription factors and recruiting chromatin modifiers to the promoters of E2F target genes. Here we show that RB also localizes to DNA double-strand breaks (DSBs) dependent on E2F1 and ATM kinase activity and promotes DSB repair through homologous recombination (HR), and its loss results in genome instability. RB is necessary for the recruitment of the BRG1 ATPase to DSBs, which stimulates DNA end resection and HR. A knock-in mutation of the ATM phosphorylation site on E2F1 (S29A) prevents the interaction between E2F1 and TopBP1 and recruitment of RB, E2F1, and BRG1 to DSBs. This knock-in mutation also impairs DNA repair, increases genomic instability, and renders mice hypersensitive to IR. Importantly, depletion of RB in osteosarcoma and breast cancer cell lines results in sensitivity to DNA-damaging drugs, which is further exacerbated by poly-ADP ribose polymerase (PARP) inhibitors. We uncovered a novel, nontranscriptional function for RB in HR, which could contribute to genome instability associated with RB loss.
Collapse
Affiliation(s)
- Renier Vélez-Cruz
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA
| | - Swarnalatha Manickavinayaham
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA
| | - Anup K Biswas
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA
| | - Regina Weaks Clary
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA.,The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77225, USA
| | - Tolkappiyan Premkumar
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA.,The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77225, USA
| | - Francesca Cole
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA.,The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77225, USA
| | - David G Johnson
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville Texas 78957, USA.,The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77225, USA
| |
Collapse
|
4
|
Teta M, Choi YS, Okegbe T, Wong G, Tam OH, Chong MMW, Seykora JT, Nagy A, Littman DR, Andl T, Millar SE. Inducible deletion of epidermal Dicer and Drosha reveals multiple functions for miRNAs in postnatal skin. Development 2012; 139:1405-16. [PMID: 22434867 DOI: 10.1242/dev.070920] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
MicroRNAs (miRNAs) regulate the expression of many mammalian genes and play key roles in embryonic hair follicle development; however, little is known of their functions in postnatal hair growth. We compared the effects of deleting the essential miRNA biogenesis enzymes Drosha and Dicer in mouse skin epithelial cells at successive postnatal time points. Deletion of either Drosha or Dicer during an established growth phase (anagen) caused failure of hair follicles to enter a normal catagen regression phase, eventual follicular degradation and stem cell loss. Deletion of Drosha or Dicer in resting phase follicles did not affect follicular structure or epithelial stem cell maintenance, and stimulation of anagen by hair plucking caused follicular proliferation and formation of a primitive transient amplifying matrix population. However, mutant matrix cells exhibited apoptosis and DNA damage and hair follicles rapidly degraded. Hair follicle defects at early time points post-deletion occurred in the absence of inflammation, but a dermal inflammatory response and hyperproliferation of interfollicular epidermis accompanied subsequent hair follicle degradation. These data reveal multiple functions for Drosha and Dicer in suppressing DNA damage in rapidly proliferating follicular matrix cells, facilitating catagen and maintaining follicular structures and their associated stem cells. Although Drosha and Dicer each possess independent non-miRNA-related functions, the similarity in phenotypes of the inducible epidermal Drosha and Dicer mutants indicates that these defects result primarily from failure of miRNA processing. Consistent with this, Dicer deletion resulted in the upregulation of multiple direct targets of the highly expressed epithelial miRNA miR-205.
Collapse
Affiliation(s)
- Monica Teta
- Department of Dermatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|