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Kamens JL, Nance S, Koss C, Xu B, Cotton A, Lam JW, Garfinkle EAR, Nallagatla P, Smith AMR, Mitchell S, Ma J, Currier D, Wright WC, Kavdia K, Pagala VR, Kim W, Wallace LM, Cho JH, Fan Y, Seth A, Twarog N, Choi JK, Obeng EA, Hatley ME, Metzger ML, Inaba H, Jeha S, Rubnitz JE, Peng J, Chen T, Shelat AA, Guy RK, Gruber TA. Proteasome inhibition targets the KMT2A transcriptional complex in acute lymphoblastic leukemia. Nat Commun 2023; 14:809. [PMID: 36781850 PMCID: PMC9925443 DOI: 10.1038/s41467-023-36370-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/26/2023] [Indexed: 02/15/2023] Open
Abstract
Rearrangments in Histone-lysine-N-methyltransferase 2A (KMT2Ar) are associated with pediatric, adult and therapy-induced acute leukemias. Infants with KMT2Ar acute lymphoblastic leukemia (ALL) have a poor prognosis with an event-free-survival of 38%. Herein we evaluate 1116 FDA approved compounds in primary KMT2Ar infant ALL specimens and identify a sensitivity to proteasome inhibition. Upon exposure to this class of agents, cells demonstrate a depletion of histone H2B monoubiquitination (H2Bub1) and histone H3 lysine 79 dimethylation (H3K79me2) at KMT2A target genes in addition to a downregulation of the KMT2A gene expression signature, providing evidence that it targets the KMT2A transcriptional complex and alters the epigenome. A cohort of relapsed/refractory KMT2Ar patients treated with this approach on a compassionate basis had an overall response rate of 90%. In conclusion, we report on a high throughput drug screen in primary pediatric leukemia specimens whose results translate into clinically meaningful responses. This innovative treatment approach is now being evaluated in a multi-institutional upfront trial for infants with newly diagnosed ALL.
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Affiliation(s)
- Jennifer L Kamens
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephanie Nance
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Cary Koss
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Beisi Xu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Anitria Cotton
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jeannie W Lam
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Pratima Nallagatla
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Amelia M R Smith
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Sharnise Mitchell
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jing Ma
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Duane Currier
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - William C Wright
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Kanisha Kavdia
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Vishwajeeth R Pagala
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Wonil Kim
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - LaShanale M Wallace
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ji-Hoon Cho
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yiping Fan
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Aman Seth
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Nathaniel Twarog
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - John K Choi
- Department of Pathology, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Esther A Obeng
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Mark E Hatley
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Monika L Metzger
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Hiroto Inaba
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Sima Jeha
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jeffrey E Rubnitz
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Junmin Peng
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA.,Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.,Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Anang A Shelat
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - R Kiplin Guy
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | - Tanja A Gruber
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA. .,Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA.
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Loss of FBXO9 Enhances Proteasome Activity and Promotes Aggressiveness in Acute Myeloid Leukemia. Cancers (Basel) 2019; 11:cancers11111717. [PMID: 31684170 PMCID: PMC6895989 DOI: 10.3390/cancers11111717] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 12/11/2022] Open
Abstract
The hematopoietic system is maintained throughout life by stem cells that are capable of differentiating into all hematopoietic lineages. An intimate balance between self-renewal, differentiation, and quiescence is required to maintain hematopoiesis and disruption of this balance can result in malignant transformation. FBXO9, the substrate recognition component from the SCF E3 ubiquitin ligase family, is downregulated in patients with acute myeloid leukemia (AML) compared to healthy bone marrow, and this downregulation is particularly evident in patients with inv(16) AML. To study FBXO9 in malignant hematopoiesis, we generated a conditional knockout mouse model using a novel CRISPR/Cas9 strategy. Deletion of Fbxo9 in the murine hematopoietic system showed no adverse effects on stem and progenitor cell function but in AML lead to markedly accelerated and aggressive leukemia development in mice with inv(16). Not only did Fbxo9 play a role in leukemia initiation but it also functioned to maintain AML activity and promote disease progression. Quantitative mass spectrometry from primary tumors reveals tumors lacking Fbxo9 highly express proteins associated with metastasis and invasion as well as components of the ubiquitin proteasome system. We confirmed that the loss of FBXO9 leads to increased proteasome activity and tumors cells were more sensitive to in vitro proteasome inhibition with bortezomib, suggesting that FBXO9 expression may predict patients’ response to bortezomib.
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Li YZ, Yu S, Yan PA, Gong DY, Wu FL, He Z, Yuan YY, Zhao AY, Tang X, Zhang RQ, Peng C, Cao ZX. Crotonoside exhibits selective post-inhibition effect in AML cells via inhibition of FLT3 and HDAC3/6. Oncotarget 2017; 8:103087-103099. [PMID: 29262547 PMCID: PMC5732713 DOI: 10.18632/oncotarget.20710] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 08/02/2017] [Indexed: 12/20/2022] Open
Abstract
Targeted therapies for the treatment of acute myeloid leukemia (AML), specifically the FLT3 inhibitors, have shown promising results. Nevertheless, it is very unlikely that inhibitors which target a single pathway will provide long-term disease control. Here, we report the characterization of crotonoside, a natural product extracted from Chinese medicinal herb, Croton, for the treatment of AML via inhibition of FLT3 and HDAC3/6. In vitro, crotonoside exhibited selective inhibition in AML cells. In vivo, crotonoside treatment at 70 and 35 mg/kg/d produced significant AML tumor inhibition rates of 93.5% and 73.6%, respectively. Studies on the anti-AML mechanism of crotonoside demonstrated a significant inhibition of FLT3 signaling, cell cycle arrest in G0/G1 phase, and apoptosis. In contrast to classic FLT3 inhibitor; sunitinib, crotonoside was able to selectively suppress the expression of HDAC3 and HDAC6 without altering the expression of other HDAC isoforms. Inhibitors of HDAC3 and HDAC6; RGFP966 and HPOB, respectively, also exhibited selective inhibition in AML cells. Furthermore, we established novel signaling pathways including HDAC3/NF-κB-p65 and HDAC6/c-Myc besides FLT3/c-Myc which are aberrantly regulated in the progression of AML. In addition, crotonoside alone or the combination of sunitinib/RFP966/HPOB exhibited a significant post-inhibition effect in AML cells by the inhibition of FLT3 and HDAC3/6. Inhibitors targeting the FLT3 and HDAC3/6 might provide a more effective treatment strategy for AML. Taken together, the present study suggests that crotonoside could be a promising candidate for the treatment of AML, and deserves further investigations.
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Affiliation(s)
- Yu-Zhi Li
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Si Yu
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Pei-Ao Yan
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Dao-Yin Gong
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Fang-Li Wu
- Second Clinical Medical College, Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Zhi He
- Second Clinical Medical College, Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Yu-Yao Yuan
- Second Clinical Medical College, Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - An-Yan Zhao
- Second Clinical Medical College, Chengdu University of Traditional Chinese Medicine, Sichuan, China
| | - Xue Tang
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Ruo-Qi Zhang
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Cheng Peng
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
| | - Zhi-Xing Cao
- Pharmacy College, Chengdu University of Traditional Chinese Medicine, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, Key Laboratory of Systematic Research, Development and Utilization of Chinese Medicine Resources in Sichuan Province-Key Laboratory Breeding Base of Co-founded by Sichuan Province and MOST, Sichuan, China
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Abstract
Acute myeloid leukemia (AML) is deadly hematologic malignancy. Despite a well-characterized genetic and molecular landscape, targeted therapies for AML have failed to significantly improve clinical outcomes. Over the past decade, proteasome inhibition has been demonstrated to be an effective therapeutic strategy in several hematologic malignancies. Proteasome inhibitors, such as bortezomib and carfilzomib, have become mainstays of treatment for multiple myeloma and mantle cell lymphoma. In light of this success, there has been a surge of literature exploring both the role of the proteasome and the effects of proteasome inhibition in AML. Pre-clinical studies have demonstrated that proteasome inhibition disrupts proliferative cell signaling pathways, exhibits cytotoxic synergism with other chemotherapeutics and induces autophagy of cancer-related proteins. Meanwhile, clinical trials incorporating bortezomib into combination chemotherapy regimens have reported a range of responses in AML patients, with complete remission rates >80% in some cases. Taken together, this preclinical and clinical evidence suggests that inhibition of the proteasome may be efficacious in this disease. In an effort to focus further investigation into this area, these recent studies and their findings are reviewed here.
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The NAE inhibitor pevonedistat interacts with the HDAC inhibitor belinostat to target AML cells by disrupting the DDR. Blood 2016; 127:2219-30. [PMID: 26851293 DOI: 10.1182/blood-2015-06-653717] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 01/27/2016] [Indexed: 02/05/2023] Open
Abstract
Two classes of novel agents, NEDD8-activating enzyme (NAE) and histone deacetylase (HDAC) inhibitors, have shown single-agent activity in acute myelogenous leukemia (AML)/myelodysplastic syndrome (MDS). Here we examined mechanisms underlying interactions between the NAE inhibitor pevonedistat (MLN4924) and the approved HDAC inhibitor belinostat in AML/MDS cells. MLN4924/belinostat coadministration synergistically induced AML cell apoptosis with or without p53 deficiency or FLT3-internal tandem duplication (ITD), whereas p53 short hairpin RNA (shRNA) knockdown or enforced FLT3-ITD expression significantly sensitized cells to the regimen. MLN4924 blocked belinostat-induced antiapoptotic gene expression through nuclear factor-κB inactivation. Each agent upregulated Bim, and Bim knockdown significantly attenuated apoptosis. Microarrays revealed distinct DNA damage response (DDR) genetic profiles between individual vs combined MLN4924/belinostat exposure. Whereas belinostat abrogated the MLN4924-activated intra-S checkpoint through Chk1 and Wee1 inhibition/downregulation, cotreatment downregulated multiple homologous recombination and nonhomologous end-joining repair proteins, triggering robust double-stranded breaks, chromatin pulverization, and apoptosis. Consistently, Chk1 or Wee1 shRNA knockdown significantly sensitized AML cells to MLN4924. MLN4924/belinostat displayed activity against primary AML or MDS cells, including those carrying next-generation sequencing-defined poor-prognostic cancer hotspot mutations, and CD34(+)/CD38(-)/CD123(+) populations, but not normal CD34(+) progenitors. Finally, combined treatment markedly reduced tumor burden and significantly prolonged animal survival (P < .0001) in AML xenograft models with negligible toxicity, accompanied by pharmacodynamic effects observed in vitro. Collectively, these findings argue that MLN4924 and belinostat interact synergistically by reciprocally disabling the DDR in AML/MDS cells. This strategy warrants further consideration in AML/MDS, particularly in disease with unfavorable genetic aberrations.
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Garcia JS, Huang M, Medeiros BC, Mitchell BS. Selective Toxicity of Investigational Ixazomib for Human Leukemia Cells Expressing Mutant Cytoplasmic NPM1: Role of Reactive Oxygen Species. Clin Cancer Res 2015; 22:1978-88. [PMID: 26634271 DOI: 10.1158/1078-0432.ccr-15-1440] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/19/2015] [Indexed: 11/16/2022]
Abstract
PURPOSE This study was performed to determine whether the investigational proteasome inhibitor ixazomib demonstrated selective antineoplastic activity against acute myelogenous leukemia cells expressing a mutated nucleophosmin-1 gene and to gain a better understanding of its mechanisms of action. EXPERIMENTAL DESIGN The cytotoxic effects of ixazomib treatment were analyzed in human acute myelogenous leukemia (AML) cell lines and primary AML samples expressing wild-type or mutated NPM1 (NPMc(+)). The potential roles of oxidative stress in mediating cytotoxic activity were determined using flow cytometry, enzyme-based assays, and Western blots. RESULTS Apoptosis induced by ixazomib was abrogated by knockdown of NPM1/NPMc(+)expression using an inducible shRNA construct and enhanced by NPMc(+)overexpression. Cytotoxicity was associated with superoxide generation and was reduced by the addition of the antioxidant N-acetylcysteine. AML cells expressing NPMc(+)had significantly reduced levels of intracellular glutathione and NADPH associated with reduced antioxidant responses to drug treatment. Treatment of 3 patients with relapsed NPMc(+)AML resulted in an antileukemic effect in 1 patient as demonstrated by a marked reduction of leukemic blasts in the peripheral blood. Efficacy was associated with superoxide generation, reduced glutathione levels, and reduced mRNA and protein expression of antioxidant effectors in responding cells. CONCLUSIONS In this study, a direct association was observed between NPMc(+)expression in AML, reduced antioxidant responses, and enhanced sensitivity to an oral proteasome inhibitor that induces oxidative stress. These data suggest that intracellular determinants of antioxidant responses may be good predictors of therapeutic response to ixazomib.
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Affiliation(s)
- Jacqueline S Garcia
- Division of Hematology, Department of Medicine, Stanford University, Stanford, California.
| | - Min Huang
- Stanford Cancer Institute, Stanford University, Stanford, California
| | - Bruno C Medeiros
- Division of Hematology, Department of Medicine, Stanford University, Stanford, California. Stanford Cancer Institute, Stanford University, Stanford, California
| | - Beverly S Mitchell
- Division of Hematology, Department of Medicine, Stanford University, Stanford, California. Stanford Cancer Institute, Stanford University, Stanford, California
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Liu J, Shaik S, Dai X, Wu Q, Zhou X, Wang Z, Wei W. Targeting the ubiquitin pathway for cancer treatment. Biochim Biophys Acta Rev Cancer 2014; 1855:50-60. [PMID: 25481052 DOI: 10.1016/j.bbcan.2014.11.005] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 12/15/2022]
Abstract
Proteasome-mediated degradation is a common mechanism by which cells renew their intracellular proteins and maintain protein homeostasis. In this process, the E3 ubiquitin ligases are responsible for targeting specific substrates (proteins) for ubiquitin-mediated degradation. However, in cancer cells, the stability and the balance between oncoproteins and tumor suppressor proteins are disturbed in part due to deregulated proteasome-mediated degradation. This ultimately leads to either stabilization of oncoprotein(s) or increased degradation of tumor suppressor(s), contributing to tumorigenesis and cancer progression. Therefore, E3 ubiquitin ligases including the SCF types of ubiquitin ligases have recently evolved as promising therapeutic targets for the development of novel anti-cancer drugs. In this review, we highlighted the critical components along the ubiquitin pathway including E1, E2, various E3 enzymes and DUBs that could serve as potential drug targets and also described the available bioactive compounds that target the ubiquitin pathway to control various cancers.
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Affiliation(s)
- Jia Liu
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Shavali Shaik
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Xiangpeng Dai
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Qiong Wu
- Department of Medical Oncology, First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui 233004, China
| | - Xiuxia Zhou
- The Cyrus Tang Hematology Center and Collaborative Innovation Center of Hematology, Jiangsu Institute of Hematology, The First Affiliated Hospital, Soochow University, Suzhou 215123, China
| | - Zhiwei Wang
- The Cyrus Tang Hematology Center and Collaborative Innovation Center of Hematology, Jiangsu Institute of Hematology, The First Affiliated Hospital, Soochow University, Suzhou 215123, China.
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Hsu FT, Liu YC, Chiang IT, Liu RS, Wang HE, Lin WJ, Hwang JJ. Sorafenib increases efficacy of vorinostat against human hepatocellular carcinoma through transduction inhibition of vorinostat-induced ERK/NF-κB signaling. Int J Oncol 2014; 45:177-88. [PMID: 24807012 DOI: 10.3892/ijo.2014.2423] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Accepted: 03/24/2014] [Indexed: 12/16/2022] Open
Abstract
Sorafenib is effective for patients with advanced hepatocellular carcinoma (HCC) and particularly for those who are unsuitable to receive life-prolonging transarterial chemo-embolization. The survival benefit of sorafenib, however, is unsatisfactory. Vorinostat also known as suberoylanilide hydroxamic acid (SAHA) is a histone deacetylase (HDAC) inhibitor with anti-HCC efficacy in preclinical studies. SAHA induces nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activity in vitro, which may lead to cancer cell progression and jeopardize cytotoxic effect of SAHA in HCC. The goal of this study was to investigate whether sorafenib enhances SAHA cytotoxicity against HCC through inhibition of SAHA-induced NF-κB activity. The human HCC cell line Huh7 transfected with dual reporter genes, luciferase (luc) and thymidine kinase (tk) with NF-κB response elements, was co-transfected with red fluorescent protein (rfp) gene for non-invasive molecular imaging to assess NF-κB activity and living cells simultaneously. Cell viability assay, DNA fragmentation, western blotting, electrophoretic mobility shift assay (EMSA) and multiple modalities of molecular imaging were used to assess the combination efficacy and mechanism of sorafenib and SAHA. The administration of high-dose SAHA (10 µM) with long treatment time (48 h) in vitro, and 25 mg/kg/day by gavage in HCC-bearing nude mice to induce NF-κB activity were performed. Sorafenib inhibited SAHA-induced NF-κB activity and the expression of NF-κB-regulated effector proteins while it increased the efficacy of SAHA against HCC both in vitro and in vivo. The mechanism of sorafenib to enhance SAHA efficacy on HCC is through the suppression of ERK/NF-κB pathway, which induces extrinsic and intrinsic apoptosis. Combination of sorafenib and SAHA may have the potential as new strategy against HCC.
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Affiliation(s)
- Fei-Ting Hsu
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
| | - Yu-Chang Liu
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
| | - I-Tsang Chiang
- Department of Radiation Oncology, National Yang-Ming University Hospital, Yilan 260, Taiwan, R.O.C
| | - Ren-Shyan Liu
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan, R.O.C
| | - Hsin-Ell Wang
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
| | - Wuu-Jyh Lin
- Division of Radioisotope, Institute of Nuclear Energy Research, Taoyuan 32546, Taiwan, R.O.C
| | - Jeng-Jong Hwang
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
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