1
|
Wang P, Laster K, Jia X, Dong Z, Liu K. Targeting CRAF kinase in anti-cancer therapy: progress and opportunities. Mol Cancer 2023; 22:208. [PMID: 38111008 PMCID: PMC10726672 DOI: 10.1186/s12943-023-01903-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023] Open
Abstract
The RAS/mitogen-activated protein kinase (MAPK) signaling cascade is commonly dysregulated in human malignancies by processes driven by RAS or RAF oncogenes. Among the members of the RAF kinase family, CRAF plays an important role in the RAS-MAPK signaling pathway, as well as in the progression of cancer. Recent research has provided evidence implicating the role of CRAF in the physiological regulation and the resistance to BRAF inhibitors through MAPK-dependent and MAPK-independent mechanisms. Nevertheless, the effectiveness of solely targeting CRAF kinase activity remains controversial. Moreover, the kinase-independent function of CRAF may be essential for lung cancers with KRAS mutations. It is imperative to develop strategies to enhance efficacy and minimize toxicity in tumors driven by RAS or RAF oncogenes. The review investigates CRAF alterations observed in cancers and unravels the distinct roles of CRAF in cancers propelled by diverse oncogenes. This review also seeks to summarize CRAF-interacting proteins and delineate CRAF's regulation across various cancer hallmarks. Additionally, we discuss recent advances in pan-RAF inhibitors and their combination with other therapeutic approaches to improve treatment outcomes and minimize adverse effects in patients with RAF/RAS-mutant tumors. By providing a comprehensive understanding of the multifaceted role of CRAF in cancers and highlighting the latest developments in RAF inhibitor therapies, we endeavor to identify synergistic targets and elucidate resistance pathways, setting the stage for more robust and safer combination strategies for cancer treatment.
Collapse
Affiliation(s)
- Penglei Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Kyle Laster
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Xuechao Jia
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Zigang Dong
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
| | - Kangdong Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
- Basic Medicine Sciences Research Center, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450052, Henan, China.
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450000, Henan, China.
- Provincial Cooperative Innovation Center for Cancer Chemoprevention, Zhengzhou University, Zhengzhou, 450000, Henan, China.
| |
Collapse
|
2
|
Qian Y, Zhou L, Luk STY, Xu J, Li W, Gou H, Chen H, Kang W, Yu J, Wong CC. The sodium channel subunit SCNN1B suppresses colorectal cancer via suppression of active c-Raf and MAPK signaling cascade. Oncogene 2023; 42:601-612. [PMID: 36564468 PMCID: PMC9937924 DOI: 10.1038/s41388-022-02576-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022]
Abstract
The incidence of colorectal cancer (CRC) is rising worldwide. Here, we identified SCNN1B as an outlier down-regulated in CRC and it functions as a tumor suppressor. SCNN1B mRNA and protein expression were down-regulated in primary CRC and CRC cells. In a tissue microarray cohort (N = 153), SCNN1B protein was an independent prognostic factor for favorable outcomes in CRC. Ectopic expression of SCNN1B in CRC cell lines suppressed cell proliferation, induced apoptosis, and cell cycle arrest, and suppressed cell migration in vitro. Xenograft models validated tumor suppressive function of SCNN1B in vivo. Mechanistically, Gene Set Enrichment Analysis (GSEA) showed that SCNN1B correlates with KRAS signaling. Consistently, MAPK qPCR and kinase arrays revealed that SCNN1B suppressed MAPK signaling. In particular, SCNN1B overexpression suppressed p-MEK/p-ERK expression and SRE-mediated transcription activities, confirming blockade of Ras-Raf-MEK-ERK cascade. Mechanistically, SCNN1B did not affect KRAS activation, instead impairing activation of c-Raf by inducing its inhibitory phosphorylation and targeting active c-Raf for degradation. The ectopic expression of c-Raf fully rescued cell proliferation and colony formation in SCNN1B-overexpressing CRC cells, confirming c-Raf as the principal molecular target of SCNN1B. In summary, we identified SCNN1B as a tumor suppressor by functioning as a c-Raf antagonist, which in turn suppressed oncogenic MEK-ERK signaling.
Collapse
Affiliation(s)
- Yun Qian
- grid.263488.30000 0001 0472 9649Department of Gastroenterology and Hepatology, Shenzhen University General Hospital, Shenzhen, China ,grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Lianxin Zhou
- grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Simson Tsz Yat Luk
- grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jiaying Xu
- grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Weilin Li
- grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Hongyan Gou
- grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Huarong Chen
- grid.10784.3a0000 0004 1937 0482Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Wei Kang
- grid.10784.3a0000 0004 1937 0482Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jun Yu
- Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | - Chi Chun Wong
- Institute of Digestive Disease, Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.
| |
Collapse
|
3
|
Fujii S, Ishibashi T, Kokura M, Fujimoto T, Matsumoto S, Shidara S, Kurppa KJ, Pape J, Caton J, Morgan PR, Heikinheimo K, Kikuchi A, Jimi E, Kiyoshima T. RAF1-MEK/ERK pathway-dependent ARL4C expression promotes ameloblastoma cell proliferation and osteoclast formation. J Pathol 2021; 256:119-133. [PMID: 34622442 DOI: 10.1002/path.5814] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 09/10/2021] [Accepted: 10/05/2021] [Indexed: 12/17/2022]
Abstract
Ameloblastoma is an odontogenic neoplasm characterized by slow intraosseous growth with progressive jaw resorption. Recent reports have revealed that ameloblastoma harbours an oncogenic BRAFV600E mutation with mitogen-activated protein kinase (MAPK) pathway activation and described cases of ameloblastoma harbouring a BRAFV600E mutation in which patients were successfully treated with a BRAF inhibitor. Therefore, the MAPK pathway may be involved in the development of ameloblastoma; however, the precise mechanism by which it induces ameloblastoma is unclear. The expression of ADP-ribosylation factor (ARF)-like 4c (ARL4C), induced by a combination of the EGF-MAPK pathway and Wnt/β-catenin signalling, has been shown to induce epithelial morphogenesis. It was also reported that the overexpression of ARL4C, due to alterations in the EGF/RAS-MAPK pathway and Wnt/β-catenin signalling, promotes tumourigenesis. However, the roles of ARL4C in ameloblastoma are unknown. We investigated the involvement of ARL4C in the development of ameloblastoma. In immunohistochemical analyses of tissue specimens obtained from 38 ameloblastoma patients, ARL4C was hardly detected in non-tumour regions but tumours frequently showed strong expression of ARL4C, along with the expression of both BRAFV600E and RAF1 (also known as C-RAF). Loss-of-function experiments using inhibitors or siRNAs revealed that ARL4C elevation depended on the RAF1-MEK/ERK pathway in ameloblastoma cells. It was also shown that the RAF1-ARL4C and BRAFV600E-MEK/ERK pathways promoted cell proliferation independently. ARL4C-depleted tumour cells (generated by knockdown or knockout) exhibited decreased proliferation and migration capabilities. Finally, when ameloblastoma cells were co-cultured with mouse bone marrow cells and primary osteoblasts, ameloblastoma cells induced osteoclast formation. ARL4C elevation in ameloblastoma further promoted its formation capabilities through the increased RANKL expression of mouse bone marrow cells and/or primary osteoblasts. These results suggest that the RAF1-MEK/ERK-ARL4C axis, which may function in cooperation with the BRAFV600E-MEK/ERK pathway, promotes ameloblastoma development. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Shinsuke Fujii
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Takuma Ishibashi
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Megumi Kokura
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Tatsufumi Fujimoto
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Shinji Matsumoto
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan.,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Japan
| | - Satsuki Shidara
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Kari J Kurppa
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, and Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Judith Pape
- Division of Surgery and Interventional Science, Department of Targeted Intervention, Centre for 3D Models of Health and Disease, University College London, London, UK
| | - Javier Caton
- Department of Anatomy and Embryology, Faculty of Medicine, University Complutense Madrid, Madrid, Spain
| | - Peter R Morgan
- Head & Neck Pathology, King's College London, Guy's Hospital, London, UK
| | - Kristiina Heikinheimo
- Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Turku and Turku University Hospital, Turku, Finland
| | - Akira Kikuchi
- Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Eijiro Jimi
- Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.,Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Tamotsu Kiyoshima
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| |
Collapse
|
4
|
Yen I, Shanahan F, Lee J, Hong YS, Shin SJ, Moore AR, Sudhamsu J, Chang MT, Bae I, Dela Cruz D, Hunsaker T, Klijn C, Liau NPD, Lin E, Martin SE, Modrusan Z, Piskol R, Segal E, Venkatanarayan A, Ye X, Yin J, Zhang L, Kim JS, Lim HS, Kim KP, Kim YJ, Han HS, Lee SJ, Kim ST, Jung M, Hong YH, Noh YS, Choi M, Han O, Nowicka M, Srinivasan S, Yan Y, Kim TW, Malek S. ARAF mutations confer resistance to the RAF inhibitor belvarafenib in melanoma. Nature 2021; 594:418-423. [PMID: 33953400 DOI: 10.1038/s41586-021-03515-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 04/05/2021] [Indexed: 02/06/2023]
Abstract
Although RAF monomer inhibitors (type I.5, BRAF(V600)) are clinically approved for the treatment of BRAFV600-mutant melanoma, they are ineffective in non-BRAFV600 mutant cells1-3. Belvarafenib is a potent and selective RAF dimer (type II) inhibitor that exhibits clinical activity in patients with BRAFV600E- and NRAS-mutant melanomas. Here we report the first-in-human phase I study investigating the maximum tolerated dose, and assessing the safety and preliminary efficacy of belvarafenib in BRAFV600E- and RAS-mutated advanced solid tumours (NCT02405065, NCT03118817). By generating belvarafenib-resistant NRAS-mutant melanoma cells and analysing circulating tumour DNA from patients treated with belvarafenib, we identified new recurrent mutations in ARAF within the kinase domain. ARAF mutants conferred resistance to belvarafenib in both a dimer- and a kinase activity-dependent manner. Belvarafenib induced ARAF mutant dimers, and dimers containing mutant ARAF were active in the presence of inhibitor. ARAF mutations may serve as a general resistance mechanism for RAF dimer inhibitors as the mutants exhibit reduced sensitivity to a panel of type II RAF inhibitors. The combination of RAF plus MEK inhibition may be used to delay ARAF-driven resistance and suggests a rational combination for clinical use. Together, our findings reveal specific and compensatory functions for the ARAF isoform and implicate ARAF mutations as a driver of resistance to RAF dimer inhibitors.
Collapse
Affiliation(s)
- Ivana Yen
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Frances Shanahan
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Jeeyun Lee
- Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.,Department of Intelligence Precision Healthcare Convergence, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Yong Sang Hong
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Sang Joon Shin
- Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Amanda R Moore
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Jawahar Sudhamsu
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA.,Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
| | - Matthew T Chang
- Department of Bioinformatics, Genentech Inc., South San Francisco, CA, USA
| | - Inhwan Bae
- Department of New Chemical Entity Discovery, Hanmi Research Center, Hanmi Pharmaceutical Co., Ltd., Seoul, South Korea
| | - Darlene Dela Cruz
- Department of Translational Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Thomas Hunsaker
- Department of Translational Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Christiaan Klijn
- Department of Bioinformatics, Genentech Inc., South San Francisco, CA, USA
| | - Nicholas P D Liau
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
| | - Eva Lin
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Scott E Martin
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Zora Modrusan
- Department of Microchemistry, Proteomics and Lipidomics, Genentech Inc., South San Francisco, CA, USA
| | - Robert Piskol
- Department of Bioinformatics, Genentech Inc., South San Francisco, CA, USA
| | - Ehud Segal
- Department of Translational Oncology, Genentech Inc., South San Francisco, CA, USA
| | | | - Xin Ye
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA
| | - Jianping Yin
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
| | - Liangxuan Zhang
- Department of Oncology Biomarker Development, Genentech Inc., South San Francisco, CA, USA
| | - Jin-Soo Kim
- Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, South Korea
| | - Hyeong-Seok Lim
- Department of Clinical Pharmacology and Therapeutics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Kyu-Pyo Kim
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Yu Jung Kim
- Division of Hematology and Medical Oncology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Hye Sook Han
- Department of Internal Medicine, Chungbuk National University Hospital, Chungbuk National University College of Medicine, Cheongju, South Korea
| | - Soo Jung Lee
- Department of Oncology/Hematology, Kyungpook National University Chilgok Hospital, Kyungpook National University, Daegu, South Korea
| | - Seung Tae Kim
- Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Minkyu Jung
- Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Yoon-Hee Hong
- Department of Clinical Research and Development, Hanmi Pharmaceutical Co., Ltd., Seoul, South Korea
| | - Young Su Noh
- Department of Clinical Research and Development, Hanmi Pharmaceutical Co., Ltd., Seoul, South Korea
| | - Munjeong Choi
- Department of Clinical Research and Development, Hanmi Pharmaceutical Co., Ltd., Seoul, South Korea
| | - Oakpil Han
- Department of Clinical Research and Development, Hanmi Pharmaceutical Co., Ltd., Seoul, South Korea
| | - Malgorzata Nowicka
- Department of Oncology Biomarker Development, Genentech Inc., South San Francisco, CA, USA
| | - Shrividhya Srinivasan
- Department of Oncology Biomarker Development, Genentech Inc., South San Francisco, CA, USA
| | - Yibing Yan
- Department of Oncology Biomarker Development, Genentech Inc., South San Francisco, CA, USA
| | - Tae Won Kim
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
| | - Shiva Malek
- Department of Discovery Oncology, Genentech Inc., South San Francisco, CA, USA.
| |
Collapse
|
5
|
Vera O, Bok I, Jasani N, Nakamura K, Xu X, Mecozzi N, Angarita A, Wang K, Tsai KY, Karreth FA. A MAPK/miR-29 Axis Suppresses Melanoma by Targeting MAFG and MYBL2. Cancers (Basel) 2021; 13:1408. [PMID: 33808771 PMCID: PMC8003541 DOI: 10.3390/cancers13061408] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/15/2021] [Accepted: 03/15/2021] [Indexed: 12/12/2022] Open
Abstract
The miR-29 family of microRNAs is encoded by two clusters, miR-29b1~a and miR-29b2~c, and is regulated by several oncogenic and tumor suppressive stimuli. While in vitro evidence suggests a tumor suppressor role for miR-29 in melanoma, the mechanisms underlying its deregulation and contribution to melanomagenesis have remained elusive. Using various in vitro systems, we show that oncogenic MAPK signaling paradoxically stimulates transcription of pri-miR-29b1~a and pri-miR-29b2~c, the latter in a p53-dependent manner. Expression analyses in melanocytes, melanoma cells, nevi, and primary melanoma revealed that pri-miR-29b2~c levels decrease during melanoma progression. Inactivation of miR-29 in vivo with a miRNA sponge in a rapid melanoma mouse model resulted in accelerated tumor development and decreased overall survival, verifying tumor suppressive potential of miR-29 in melanoma. Through integrated RNA sequencing, target prediction, and functional assays, we identified the transcription factors MAFG and MYBL2 as bona fide miR-29 targets in melanoma. Our findings suggest that attenuation of miR-29b2~c expression promotes melanoma development, at least in part, by derepressing MAFG and MYBL2.
Collapse
Affiliation(s)
- Olga Vera
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
| | - Ilah Bok
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
- Cancer Biology PhD Program, University of South Florida, Tampa, FL 33612, USA
| | - Neel Jasani
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
- Cancer Biology PhD Program, University of South Florida, Tampa, FL 33612, USA
| | - Koji Nakamura
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
| | - Xiaonan Xu
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
| | - Nicol Mecozzi
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
- Department of Biology, University of Pisa, 56126 Pisa, Italy
| | - Ariana Angarita
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
| | - Kaizhen Wang
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
- Cancer Biology PhD Program, University of South Florida, Tampa, FL 33612, USA
| | - Kenneth Y. Tsai
- Departments of Anatomic Pathology and Tumor Biology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA;
- Donald A. Adam Melanoma and Skin Cancer Center of Excellence, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Florian A. Karreth
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (O.V.); (I.B.); (N.J.); (K.N.); (X.X.); (N.M.); (A.A.); (K.W.)
- Donald A. Adam Melanoma and Skin Cancer Center of Excellence, Moffitt Cancer Center, Tampa, FL 33612, USA
| |
Collapse
|
6
|
Cope N, Novak B, Candelora C, Wong K, Cavallo M, Gunderwala A, Liu Z, Li Y, Wang Z. Biochemical Characterization of Full-Length Oncogenic BRAF V600E together with Molecular Dynamics Simulations Provide Insight into the Activation and Inhibition Mechanisms of RAF Kinases. Chembiochem 2019; 20:2850-2861. [PMID: 31152574 DOI: 10.1002/cbic.201900266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Indexed: 12/12/2022]
Abstract
The most prevalent BRAF mutation, V600E, occurs frequently in melanoma and other cancers. Although extensive progress has been made toward understanding the biology of RAF kinases, little in vitro characterization of full-length BRAFV600E is available. Herein, we show the successful purification of active, full-length BRAFV600E from mammalian cells for in vitro experiments. Our biochemical characterization of intact BRAFV600E together with molecular dynamics (MD) simulations of the BRAF kinase domain and cell-based assays demonstrate that BRAFV600E has several unique features that contribute to its tumorigenesis. Firstly, steady-state kinetic analyses reveal that purified BRAFV600E is more active than fully activated wild-type BRAF; this is consistent with the notion that elevated signaling output is necessary for transformation. Secondly, BRAFV600E has a higher potential to form oligomers, despite the fact that the V600E substitution confers constitutive kinase activation independent of an intact side-to-side dimer interface. Thirdly, BRAFV600E bypasses inhibitory P-loop phosphorylation to enforce the necessary elevated signaling output for tumorigenesis. Together, these results provide new insight into the biochemical properties of BRAFV600E , complementing the understanding of BRAF regulation under normal and disease conditions.
Collapse
Affiliation(s)
- Nicholas Cope
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Borna Novak
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Christine Candelora
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Kenneth Wong
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Maria Cavallo
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Amber Gunderwala
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Zhiwei Liu
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| | - Yana Li
- Eukaryotic Tissue Culture Facility, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Zhihong Wang
- Department of Chemistry and Biochemistry, University of the Sciences, Philadelphia, PA, 19104, USA
| |
Collapse
|
7
|
Trojaniello C, Festino L, Vanella V, Ascierto PA. Encorafenib in combination with binimetinib for unresectable or metastatic melanoma with BRAF mutations. Expert Rev Clin Pharmacol 2019; 12:259-266. [PMID: 30652516 DOI: 10.1080/17512433.2019.1570847] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Combination treatment with a BRAF inhibitor and MEK inhibitor is the standard of care for patients with advanced BRAFV600 mutation-positive melanoma. With the currently available combinations of dabrafenib plus trametinib and vemurafenib plus cobimetinib, median progression-free survival (PFS) of over 12 months has been achieved. However, treatment resistance and disease recurrence remain a clinical challenge. Areas covered: Encorafenib in combination with bimetinib offers a new approach that may offer benefits over existing BRAF/MEK inhibitor combinations. Expert opinion: While other BRAF/MEK inhibitor combinations have achieved a median overall survival (OS) of 22 months, patients with advanced BRAF mutation-positive melanoma treated with encorafenib plus binimetinib achieved a median OS of 33.6 months in the phase III COLUMBUS trial. PFS also appears to be improved with encorafenib plus binimetinib. This improved efficacy may be related to the distinct pharmacokinetics of encorafenib, with prolonged binding to the target molecule providing greater BRAF inhibition and increased potency compared with other drugs in the same class. Increased specificity of encorafenib may also result in better tolerability with less off-target effects, including reduced occurrence of pyrexia and photosensitivity. Encorafenib plus binimetinib seems likely to emerge as a valuable therapeutic alternative to established BRAF/MEK inhibitor combinations.
Collapse
Affiliation(s)
- Claudia Trojaniello
- a Unit of Melanoma, Cancer Immunotherapy and Development Therapeutics , Istituto Nazionale Tumori IRCCS Fondazione G. Pascale , Napoli , Italy
| | - Lucia Festino
- a Unit of Melanoma, Cancer Immunotherapy and Development Therapeutics , Istituto Nazionale Tumori IRCCS Fondazione G. Pascale , Napoli , Italy
| | - Vito Vanella
- a Unit of Melanoma, Cancer Immunotherapy and Development Therapeutics , Istituto Nazionale Tumori IRCCS Fondazione G. Pascale , Napoli , Italy
| | - Paolo A Ascierto
- a Unit of Melanoma, Cancer Immunotherapy and Development Therapeutics , Istituto Nazionale Tumori IRCCS Fondazione G. Pascale , Napoli , Italy
| |
Collapse
|
8
|
Galectin-1 knockdown improves drug sensitivity of breast cancer by reducing P-glycoprotein expression through inhibiting the Raf-1/AP-1 signaling pathway. Oncotarget 2018; 8:25097-25106. [PMID: 28212576 PMCID: PMC5421912 DOI: 10.18632/oncotarget.15341] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/16/2017] [Indexed: 12/15/2022] Open
Abstract
Galectin-1 (Gal-1), a member of the galectin family of carbohydrate binding proteins, plays a pivotal role in various cellular processes of tumorigenesis. The regulatory effect of Gal-1 on multidrug resistance (MDR) breast cancer cells is still unclear. qRT-PCR and western blot showed that Gal-1 and MDR gene 1 (MDR1) were both highly expressed in breast tumor tissues and cell lines. MTT assay and flow cytometry revealed that Gal-1 knockdown improved sensitivity to paclitaxel (PTX) and adriamycin (ADR) in MCF-7/PTX and MCF-7/ADR cells via inhibition of cell viability and promotion of cell apoptosis, while MDR1 overexpression weakened the sensitivity to PTX and ADR induced by Gal-1 knockdown. Furthermore, the negative effects of Gal-1 knockdown on sensitivity to PTX and ADR in MCF-7/PTX and MCF-7/ADR cells were revealed to be mediated via the suppression of Raf-1/AP-1 pathway. In conclusion, Gal-1 knockdown dramatically improved drug sensitivity of breast cancer by reducing P-glycoprotein (P-gp) expression via inhibiting the Raf-1/AP-1 pathway, providing a novel therapeutic target to overcome MDR in breast cancer.
Collapse
|
9
|
Adelmann CH, Ching G, Du L, Saporito RC, Bansal V, Pence LJ, Liang R, Lee W, Tsai KY. Comparative profiles of BRAF inhibitors: the paradox index as a predictor of clinical toxicity. Oncotarget 2017; 7:30453-60. [PMID: 27028853 PMCID: PMC5058692 DOI: 10.18632/oncotarget.8351] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/04/2016] [Indexed: 12/11/2022] Open
Abstract
BRAF inhibitor (BRAFi) therapy is associated with the induction of neoplasia, most commonly cutaneous squamous cell carcinoma (cuSCC). This toxicity is explained in part by “paradoxical ERK activation,” or the hyperactivation of ERK signaling by BRAFi in BRAF wild-type cells. However, the rate of cuSCC induction varies widely among BRAFi. To explore this mechanistically, we profiled paradoxical ERK activation by vemurafenib, dabrafenib, encorafenib (LGX818), and PLX8394, demonstrating that vemurafenib induces ERK activation the greatest, while dabrafenib and encorafenib have higher “paradox indices”, defined as the pERK activation EC80 divided by the IC80 against A375, corresponding to wider therapeutic windows for achieving tumor inhibition without paradoxical ERK activation. Our results identify differences in the paradox indices of these compounds as a potential mechanism for the differences in cuSCC induction rates and highlight the utility of using ERK activity as a biomarker for maximizing the clinical utility of BRAFi.
Collapse
Affiliation(s)
- Charles H Adelmann
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Grace Ching
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Lili Du
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Rachael C Saporito
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Varun Bansal
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Lindy J Pence
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Roger Liang
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Woojin Lee
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| | - Kenneth Y Tsai
- Department of Translational Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Dermatology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA.,Graduate School of Biomedical Sciences, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA
| |
Collapse
|
10
|
Neiswender JV, Kortum RL, Bourque C, Kasheta M, Zon LI, Morrison DK, Ceol CJ. KIT Suppresses BRAF V600E-Mutant Melanoma by Attenuating Oncogenic RAS/MAPK Signaling. Cancer Res 2017; 77:5820-5830. [PMID: 28947418 DOI: 10.1158/0008-5472.can-17-0473] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/17/2017] [Accepted: 09/08/2017] [Indexed: 12/30/2022]
Abstract
The receptor tyrosine kinase KIT promotes survival and migration of melanocytes during development, and excessive KIT activity hyperactivates the RAS/MAPK pathway and can drive formation of melanomas, most notably of rare melanomas that occur on volar and mucosal surfaces of the skin. The much larger fraction of melanomas that occur on sun-exposed skin is driven primarily by BRAF- or NRAS-activating mutations, but these melanomas exhibit a surprising loss of KIT expression, which raises the question of whether loss of KIT in these tumors facilitates tumorigenesis. To address this question, we introduced a kit(lf) mutation into a strain of Tg(mitfa:BRAFV600E); p53(lf) melanoma-prone zebrafish. Melanoma onset was accelerated in kit(lf); Tg(mitfa:BRAFV600E); p53(lf) fish. Tumors from kit(lf) animals were more invasive and had higher RAS/MAPK pathway activation. KIT knockdown also increased RAS/MAPK pathway activation in a BRAFV600E-mutant human melanoma cell line. We found that pathway stimulation upstream of BRAFV600E could paradoxically reduce signaling downstream of BRAFV600E, and wild-type BRAF was necessary for this effect, suggesting that its activation can dampen oncogenic BRAFV600E signaling. In vivo, expression of wild-type BRAF delayed melanoma onset, but only in a kit-dependent manner. Together, these results suggest that KIT can activate signaling through wild-type RAF proteins, thus interfering with oncogenic BRAFV600E-driven melanoma formation. Cancer Res; 77(21); 5820-30. ©2017 AACR.
Collapse
Affiliation(s)
- James V Neiswender
- Program in Molecular Medicine, Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Robert L Kortum
- Laboratory of Cell and Developmental Signaling, National Cancer Institute at Frederick, Frederick, Maryland.,Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Caitlin Bourque
- Howard Hughes Medical Institute, Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Melissa Kasheta
- Program in Molecular Medicine, Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Leonard I Zon
- Howard Hughes Medical Institute, Stem Cell Program and Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Deborah K Morrison
- Laboratory of Cell and Developmental Signaling, National Cancer Institute at Frederick, Frederick, Maryland
| | - Craig J Ceol
- Program in Molecular Medicine, Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts.
| |
Collapse
|
11
|
Cisowski J, Sayin VI, Liu M, Karlsson C, Bergo MO. Oncogene-induced senescence underlies the mutual exclusive nature of oncogenic KRAS and BRAF. Oncogene 2015; 35:1328-33. [PMID: 26028035 DOI: 10.1038/onc.2015.186] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 03/06/2015] [Accepted: 04/12/2015] [Indexed: 01/02/2023]
Abstract
KRAS and BRAF are among the most commonly mutated oncogenes in human cancer that contribute to tumorigenesis in both distinct and overlapping tissues. However, KRAS and BRAF mutations are mutually exclusive; they never occur in the same tumor cell. The reason for the mutual exclusivity is unknown, but there are several possibilities. The two mutations could be functionally redundant and not create a selective advantage to tumor cells. Alternatively, they could be deleterious for the tumor cell and induce apoptosis or senescence. To distinguish between these possibilities, we activated the expression of BRAF(V600E) and KRAS(G12D) from their endogenous promoters in mouse lungs. Although the tumor-forming ability of BRAF(V600E) was higher than KRAS(G12D), KRAS(G12D) tumors were larger and more advanced. Coactivation of BRAF(V600E) and KRAS(G12D) markedly reduced lung tumor numbers and overall tumor burden compared with activation of BRAF(V600E) alone. Moreover, several tumors expressed only one oncogene, suggesting negative selection against expression of both. Similarly, expression of both oncogenes in mouse embryonic fibroblasts essentially stopped proliferation. The expression of both oncogenes hyperactivated the MEK-ERK-cyclin D pathway but reduced proliferation by increasing the production of p15, p16 and p19 proteins encoded by the Ink4/Arf locus and thereby increased senescence-associated β-galactosidase-positive cells. The data suggest that coexpression of BRAF(V600E) and KRAS(G12D) in early tumorigenesis leads to negative selection due to oncogene-induced senescence.
Collapse
Affiliation(s)
- J Cisowski
- Department of Molecular and Clinical Medicine, Sahlgrenska Cancer Center, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - V I Sayin
- Department of Molecular and Clinical Medicine, Sahlgrenska Cancer Center, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.,Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - M Liu
- Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - C Karlsson
- Department of Molecular and Clinical Medicine, Sahlgrenska Cancer Center, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - M O Bergo
- Department of Molecular and Clinical Medicine, Sahlgrenska Cancer Center, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
12
|
Karreth FA, Reschke M, Ruocco A, Ng C, Chapuy B, Léopold V, Sjoberg M, Keane TM, Verma A, Ala U, Tay Y, Wu D, Seitzer N, Velasco-Herrera MDC, Bothmer A, Fung J, Langellotto F, Rodig SJ, Elemento O, Shipp MA, Adams DJ, Chiarle R, Pandolfi PP. The BRAF pseudogene functions as a competitive endogenous RNA and induces lymphoma in vivo. Cell 2015; 161:319-32. [PMID: 25843629 DOI: 10.1016/j.cell.2015.02.043] [Citation(s) in RCA: 255] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 12/19/2014] [Accepted: 02/02/2015] [Indexed: 12/14/2022]
Abstract
Research over the past decade has suggested important roles for pseudogenes in physiology and disease. In vitro experiments demonstrated that pseudogenes contribute to cell transformation through several mechanisms. However, in vivo evidence for a causal role of pseudogenes in cancer development is lacking. Here, we report that mice engineered to overexpress either the full-length murine B-Raf pseudogene Braf-rs1 or its pseudo "CDS" or "3' UTR" develop an aggressive malignancy resembling human diffuse large B cell lymphoma. We show that Braf-rs1 and its human ortholog, BRAFP1, elicit their oncogenic activity, at least in part, as competitive endogenous RNAs (ceRNAs) that elevate BRAF expression and MAPK activation in vitro and in vivo. Notably, we find that transcriptional or genomic aberrations of BRAFP1 occur frequently in multiple human cancers, including B cell lymphomas. Our engineered mouse models demonstrate the oncogenic potential of pseudogenes and indicate that ceRNA-mediated microRNA sequestration may contribute to the development of cancer.
Collapse
Affiliation(s)
- Florian A Karreth
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Markus Reschke
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Anna Ruocco
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Christopher Ng
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Bjoern Chapuy
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Valentine Léopold
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Marcela Sjoberg
- Experimental Cancer Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1HH, UK
| | - Thomas M Keane
- Experimental Cancer Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1HH, UK
| | - Akanksha Verma
- Department of Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Ugo Ala
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yvonne Tay
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - David Wu
- Meyer Cancer Center, Weill Cornell Medical College, New York, NY 10021, USA
| | - Nina Seitzer
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | | | - Anne Bothmer
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Jacqueline Fung
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Fernanda Langellotto
- Department of Pathology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Scott J Rodig
- Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Olivier Elemento
- Department of Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Margaret A Shipp
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - David J Adams
- Experimental Cancer Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1HH, UK
| | - Roberto Chiarle
- Department of Pathology, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; Department of Molecular Biotechnology and Health Sciences, University of Torino, 10124 Torino, Italy
| | - Pier Paolo Pandolfi
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| |
Collapse
|
13
|
Samatar AA, Poulikakos PI. Targeting RAS-ERK signalling in cancer: promises and challenges. Nat Rev Drug Discov 2015; 13:928-42. [PMID: 25435214 DOI: 10.1038/nrd4281] [Citation(s) in RCA: 798] [Impact Index Per Article: 88.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The RAS-RAF-MEK-ERK signalling pathway is hyperactivated in a high percentage of tumours, most frequently owing to activating mutations of the KRAS, NRAS and BRAF genes. Recently, the use of compounds targeting components of ERK signalling, such as RAF or MEK inhibitors, has led to substantial improvement in clinical outcome in metastatic melanoma and has shown promising clinical activity in additional tumour types. However, response rates are highly variable and the efficacy of these drugs is primarily limited by the development of resistance. Both intrinsic and acquired resistance to RAF and MEK inhibitors are frequently associated with the persistence of ERK signalling in the presence of the drug, implying the need for more innovative approaches to target the pathway.
Collapse
Affiliation(s)
- Ahmed A Samatar
- TheraMet Biosciences, 6 Jacob Drive, Princeton Junction, New Jersey 08550, USA
| | - Poulikos I Poulikakos
- Department of Oncological Sciences and Department of Dermatology, The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, New York 10029, USA
| |
Collapse
|
14
|
BRAF inhibitors: experience in thyroid cancer and general review of toxicity. Discov Oncol 2014; 6:21-36. [PMID: 25467940 DOI: 10.1007/s12672-014-0207-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/11/2014] [Indexed: 12/20/2022] Open
Abstract
The US Food and Drug Administration-approved BRAF inhibitors, vemurafenib and dabrafenib, have demonstrated superior efficacy in patients with BRAF-mutant melanomas but have limited efficacy in BRAF-mutant colorectal cancer. Little is known at this time regarding BRAF inhibitors in thyroid cancer. Initial reports in patients with progressive, radioactive iodine-refractory BRAF-mutant papillary thyroid cancer suggest response rates of approximately 30-40%. In this review, we discuss BRAF inhibitors in the context of thyroid cancer, the toxicities associated with BRAF inhibitors, and the suggested management of those toxicities. The management of vemurafenib and dabrafenib toxicities is applicable across all tumor types and may serve as a practical guide to their use.
Collapse
|
15
|
Holderfield M, Deuker MM, McCormick F, McMahon M. Targeting RAF kinases for cancer therapy: BRAF-mutated melanoma and beyond. Nat Rev Cancer 2014; 14:455-67. [PMID: 24957944 PMCID: PMC4250230 DOI: 10.1038/nrc3760] [Citation(s) in RCA: 588] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The identification of mutationally activated BRAF in many cancers altered our conception of the part played by the RAF family of protein kinases in oncogenesis. In this Review, we describe the development of BRAF inhibitors and the results that have emerged from their analysis in both the laboratory and the clinic. We discuss the spectrum of RAF mutations in human cancer and the complex interplay between the tissue of origin and the response to RAF inhibition. Finally, we enumerate mechanisms of resistance to BRAF inhibition that have been characterized and postulate how strategies of RAF pathway inhibition may be extended in scope to benefit not only the thousands of patients who are diagnosed annually with BRAF-mutated metastatic melanoma but also the larger patient population with malignancies harbouring mutationally activated RAF genes that are ineffectively treated with the current generation of BRAF kinase inhibitors.
Collapse
Affiliation(s)
| | | | - Frank McCormick
- Corresponding Authors: Frank McCormick & Martin McMahon, Diller Family Cancer Research Bldg., 1450 Third Street, University of California, San Francisco, CA 94158, USA, &
| | - Martin McMahon
- Corresponding Authors: Frank McCormick & Martin McMahon, Diller Family Cancer Research Bldg., 1450 Third Street, University of California, San Francisco, CA 94158, USA, &
| |
Collapse
|
16
|
"RAF" neighborhood: protein-protein interaction in the Raf/Mek/Erk pathway. FEBS Lett 2014; 588:2398-406. [PMID: 24937142 PMCID: PMC4099524 DOI: 10.1016/j.febslet.2014.06.025] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 12/19/2022]
Abstract
The Raf/Mek/Erk signaling pathway, activated downstream of Ras primarily to promote proliferation, represents the best studied of the evolutionary conserved MAPK cascades. The investigation of the pathway has continued unabated since its discovery roughly 30 years ago. In the last decade, however, the identification of unexpected in vivo functions of pathway components, as well as the discovery of Raf mutations in human cancer, the ensuing quest for inhibitors, and the efforts to understand their mechanism of action, have boosted interest tremendously. From this large body of work, protein-protein interaction has emerged as a recurrent, crucial theme. This review focuses on the role of protein complexes in the regulation of the Raf/Mek/Erk pathway and in its cross-talk with other signaling cascades. Mapping these interactions and finding a way of exploiting them for therapeutic purposes is one of the challenges of future molecule-targeted therapy.
Collapse
|
17
|
Neesse A, Frese KK, Chan DS, Bapiro TE, Howat WJ, Richards FM, Ellenrieder V, Jodrell DI, Tuveson DA. SPARC independent drug delivery and antitumour effects of nab-paclitaxel in genetically engineered mice. Gut 2014; 63:974-83. [PMID: 24067278 PMCID: PMC4033275 DOI: 10.1136/gutjnl-2013-305559] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 07/24/2013] [Accepted: 07/28/2013] [Indexed: 12/16/2022]
Abstract
DESIGN Pharmacokinetic and pharmacodynamic parameters of cremophor-paclitaxel, nab-paclitaxel (human-albumin-bound paclitaxel, Abraxane) and a novel mouse-albumin-bound paclitaxel (m-nab-paclitaxel) were evaluated in genetically engineered mouse models (GEMMs) by liquid chromatography-tandem mass spectrometry (LC-MS/MS), histological and biochemical analysis. Preclinical evaluation of m-nab-paclitaxel included assessment by three-dimensional high-resolution ultrasound and molecular analysis in a novel secreted protein acidic and rich in cysteine (SPARC)-deficient GEMM of pancreatic ductal adenocarcinoma (PDA). RESULTS nab-Paclitaxel exerted its antitumoural effects in a dose-dependent manner and was associated with less toxicity compared with cremophor-paclitaxel. SPARC nullizygosity in a GEMM of PDA, Kras(G12D);p53(flox/-);p48Cre (KPfC), resulted in desmoplastic ductal pancreas tumours with impaired collagen maturation. Paclitaxel concentrations were significantly decreased in SPARC null plasma samples and tissues when administered as low-dose m-nab-paclitaxel. At the maximally tolerated dose, SPARC deficiency did not affect the intratumoural paclitaxel concentration, stromal deposition and the immediate therapeutic response. CONCLUSIONS nab-Paclitaxel accumulates and acts in a dose-dependent manner. The interaction of plasma SPARC and albumin-bound drugs is observed at low doses of nab-paclitaxel but is saturated at therapeutic doses in murine tumours. Thus, this study provides important information for future preclinical and clinical trials in PDA using nab-paclitaxel in combination with novel experimental and targeted agents.
Collapse
Affiliation(s)
- Albrecht Neesse
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
- Department of Gastroenterology, Endocrinology, Infectiology and Metabolism, Philipps University Marburg, Marburg, Germany
| | - Kristopher K Frese
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
| | - Derek S Chan
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
| | - Tashinga E Bapiro
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
| | - William J Howat
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
| | - Frances M Richards
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
| | - Volker Ellenrieder
- Department of Gastroenterology, Endocrinology, Infectiology and Metabolism, Philipps University Marburg, Marburg, Germany
| | - Duncan I Jodrell
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
| | - David A Tuveson
- Cancer Research UK Cambridge Institute, The University of Cambridge, Cambridge, UK
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| |
Collapse
|
18
|
Allosteric activation of functionally asymmetric RAF kinase dimers. Cell 2013; 154:1036-1046. [PMID: 23993095 DOI: 10.1016/j.cell.2013.07.046] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 03/18/2013] [Accepted: 07/31/2013] [Indexed: 01/07/2023]
Abstract
Although RAF kinases are critical for controlling cell growth, their mechanism of activation is incompletely understood. Recently, dimerization was shown to be important for activation. Here we show that the dimer is functionally asymmetric with one kinase functioning as an activator to stimulate activity of the partner, receiver kinase. The activator kinase did not require kinase activity but did require N-terminal phosphorylation that functioned allosterically to induce cis-autophosphorylation of the receiver kinase. Based on modeling of the hydrophobic spine assembly, we also engineered a constitutively active mutant that was independent of Ras, dimerization, and activation-loop phosphorylation. As N-terminal phosphorylation of BRAF is constitutive, BRAF initially functions to activate CRAF. N-terminal phosphorylation of CRAF was dependent on MEK, suggesting a feedback mechanism and explaining a key difference between BRAF and CRAF. Our work illuminates distinct steps in RAF activation that function to assemble the active conformation of the RAF kinase.
Collapse
|
19
|
Vin H, Ojeda SS, Ching G, Leung ML, Chitsazzadeh V, Dwyer DW, Adelmann CH, Restrepo M, Richards KN, Stewart LR, Du L, Ferguson SB, Chakravarti D, Ehrenreiter K, Baccarini M, Ruggieri R, Curry JL, Kim KB, Ciurea AM, Duvic M, Prieto VG, Ullrich SE, Dalby KN, Flores ER, Tsai KY. BRAF inhibitors suppress apoptosis through off-target inhibition of JNK signaling. eLife 2013; 2:e00969. [PMID: 24192036 PMCID: PMC3814616 DOI: 10.7554/elife.00969] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Vemurafenib and dabrafenib selectively inhibit the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) kinase, resulting in high response rates and increased survival in melanoma. Approximately 22% of individuals treated with vemurafenib develop cutaneous squamous cell carcinoma (cSCC) during therapy. The prevailing explanation for this is drug-induced paradoxical ERK activation, resulting in hyperproliferation. Here we show an unexpected and novel effect of vemurafenib/PLX4720 in suppressing apoptosis through the inhibition of multiple off-target kinases upstream of c-Jun N-terminal kinase (JNK), principally ZAK. JNK signaling is suppressed in multiple contexts, including in cSCC of vemurafenib-treated patients, as well as in mice. Expression of a mutant ZAK that cannot be inhibited reverses the suppression of JNK activation and apoptosis. Our results implicate suppression of JNK-dependent apoptosis as a significant, independent mechanism that cooperates with paradoxical ERK activation to induce cSCC, suggesting broad implications for understanding toxicities associated with BRAF inhibitors and for their use in combination therapies. DOI: http://dx.doi.org/10.7554/eLife.00969.001.
Collapse
Affiliation(s)
- Harina Vin
- Department of Immunology, University of Texas MD Anderson Cancer Center, Houston, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Vin H, Ching G, Ojeda SS, Adelmann CH, Chitsazzadeh V, Dwyer DW, Ma H, Ehrenreiter K, Baccarini M, Ruggieri R, Curry JL, Ciurea AM, Duvic M, Busaidy NL, Tannir NM, Tsai KY. Sorafenib suppresses JNK-dependent apoptosis through inhibition of ZAK. Mol Cancer Ther 2013; 13:221-9. [PMID: 24170769 DOI: 10.1158/1535-7163.mct-13-0561] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sorafenib is U.S. Food and Drug Adminstration-approved for the treatment of renal cell carcinoma and hepatocellular carcinoma and has been combined with numerous other targeted therapies and chemotherapies in the treatment of many cancers. Unfortunately, as with other RAF inhibitors, patients treated with sorafenib have a 5% to 10% rate of developing cutaneous squamous cell carcinoma (cSCC)/keratoacanthomas. Paradoxical activation of extracellular signal-regulated kinase (ERK) in BRAF wild-type cells has been implicated in RAF inhibitor-induced cSCC. Here, we report that sorafenib suppresses UV-induced apoptosis specifically by inhibiting c-jun-NH(2)-kinase (JNK) activation through the off-target inhibition of leucine zipper and sterile alpha motif-containing kinase (ZAK). Our results implicate suppression of JNK signaling, independent of the ERK pathway, as an additional mechanism of adverse effects of sorafenib. This has broad implications for combination therapies using sorafenib with other modalities that induce apoptosis.
Collapse
Affiliation(s)
- Harina Vin
- Corresponding Author: Kenneth Y. Tsai, Departments of Dermatology and Immunology, University of Texas MD Anderson Cancer Center, 7455 Fannin, Unit 907, Houston, TX 77054.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Neesse A, Frese KK, Bapiro TE, Nakagawa T, Sternlicht MD, Seeley TW, Pilarsky C, Jodrell DI, Spong SM, Tuveson DA. CTGF antagonism with mAb FG-3019 enhances chemotherapy response without increasing drug delivery in murine ductal pancreas cancer. Proc Natl Acad Sci U S A 2013; 110:12325-30. [PMID: 23836645 PMCID: PMC3725120 DOI: 10.1073/pnas.1300415110] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDA) is characterized by abundant desmoplasia and poor tissue perfusion. These features are proposed to limit the access of therapies to neoplastic cells and blunt treatment efficacy. Indeed, several agents that target the PDA tumor microenvironment promote concomitant chemotherapy delivery and increased antineoplastic response in murine models of PDA. Prior studies could not determine whether chemotherapy delivery or microenvironment modulation per se were the dominant features in treatment response, and such information could guide the optimal translation of these preclinical findings to patients. To distinguish between these possibilities, we used a chemical inhibitor of cytidine deaminase to stabilize and thereby artificially elevate gemcitabine levels in murine PDA tumors without disrupting the tumor microenvironment. Additionally, we used the FG-3019 monoclonal antibody (mAb) that is directed against the pleiotropic matricellular signaling protein connective tissue growth factor (CTGF/CCN2). Inhibition of cytidine deaminase raised the levels of activated gemcitabine within PDA tumors without stimulating neoplastic cell killing or decreasing the growth of tumors, whereas FG-3019 increased PDA cell killing and led to a dramatic tumor response without altering gemcitabine delivery. The response to FG-3019 correlated with the decreased expression of a previously described promoter of PDA chemotherapy resistance, the X-linked inhibitor of apoptosis protein. Therefore, alterations in survival cues following targeting of tumor microenvironmental factors may play an important role in treatment responses in animal models, and by extension in PDA patients.
Collapse
Affiliation(s)
- Albrecht Neesse
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
- Department of Gastroenterology, Endocrinology, and Metabolism, Philipps University Marburg, 35043 Marburg, Germany
| | - Kristopher K. Frese
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
| | - Tashinga E. Bapiro
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
- Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom
| | - Tomoaki Nakagawa
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
| | | | | | - Christian Pilarsky
- Department of General, Thoracic, and Vascular Surgery, University Hospital Carl Gustav Carus, Technical University Dresden, 01307 Dresden, Germany; and
| | - Duncan I. Jodrell
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
- Department of Oncology, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom
| | | | - David A. Tuveson
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| |
Collapse
|
22
|
Tsai KY, Nowroozi S, Kim KB. Drug safety evaluation of vemurafenib in the treatment of melanoma. Expert Opin Drug Saf 2013; 12:767-75. [DOI: 10.1517/14740338.2013.813017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
23
|
Spirli C, Morell CM, Locatelli L, Okolicsanyi S, Ferrero C, Kim AK, Fabris L, Fiorotto R, Strazzabosco M. Cyclic AMP/PKA-dependent paradoxical activation of Raf/MEK/ERK signaling in polycystin-2 defective mice treated with sorafenib. Hepatology 2012; 56:2363-74. [PMID: 22653837 PMCID: PMC3460040 DOI: 10.1002/hep.25872] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 05/25/2012] [Indexed: 12/22/2022]
Abstract
UNLABELLED Mutations in polycystins are a cause of polycystic liver disease. In polycystin-2 (PC2)-defective mice, cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)-dependent activation of the Rat Sarcoma (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen signal-regulated kinase-extracellular signal-regulated kinase (ERK) 1/2 pathway stimulates the growth of liver cysts. To test the hypothesis that sorafenib, a Raf inhibitor used for the treatment of liver and kidney cancers, inhibits liver cyst growth in PC2-defective mice, we treated PC2 (i.e., Pkd2(flox/-) :pCxCreER(TM) [Pkd2cKO]) mice with sorafenib-tosylate for 8 weeks (20-60 mg/kg/day). Sorafenib caused an unexpected increase in liver cyst area, cell proliferation (Ki67), and expression of phosphorylated ERK (pERK) compared with Pkd2cKO mice treated with vehicle. When given to epithelial cells isolated from liver cysts of Pkd2cKO mice (Pkd2cKO-cells), sorafenib progressively stimulated pERK1/2 and cell proliferation [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and bromodeoxyuridine assay (MTS)] at doses between 0.001 and 1 μM; however, both pERK1/2 and cell proliferation significantly decreased at the dose of 10 μM. Raf kinase activity assay showed that whereas B-Raf is inhibited by sorafenib in both wild-type (WT) and Pkd2cKO cells, Raf-1 is inhibited in WT cells but is significantly stimulated in Pkd2cKO cells. In Pkd2cKO cells pretreated with the PKA inhibitor 14-22 amide, myristolated (1 μM) and in mice treated with octreotide in combination with sorafenib, the paradoxical activation of Raf/ERK1/2 was abolished, and cyst growth was inhibited. CONCLUSION In PC2-defective cells, sorafenib inhibits B-Raf but paradoxically activates Raf-1, resulting in increased ERK1/2 phosphorylation, cell proliferation, and cyst growth in vivo. These effects are consistent with the ability of Raf inhibitors to transactivate Raf-1 when a PKA-activated Ras promotes Raf-1/B-Raf heterodimerization, and are inhibited by interfering with cAMP/PKA signaling both in vitro and in vivo, as shown by the reduction of liver cysts in mice treated with combined octreotide and sorafenib.
Collapse
Affiliation(s)
- Carlo Spirli
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Carola M. Morell
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
- Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| | - Luigi Locatelli
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
- Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| | - Stefano Okolicsanyi
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
- Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| | - Cecilia Ferrero
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Amy K. Kim
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Luca Fabris
- Department of Surgical, Oncological, and Gastroenterological Sciences, University of Padova, Padova, Italy
| | - Romina Fiorotto
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Mario Strazzabosco
- Liver Center & Section of Digestive Diseases, Department of Internal Medicine, Yale University, New Haven, CT, USA
- Department of Clinical Medicine and Prevention, University of Milan-Bicocca, Milan, Italy
| |
Collapse
|
24
|
Fernández IF, Pérez-Rivas LG, Blanco S, Castillo-Dominguez AA, Lozano J, Lazo PA. VRK2 anchors KSR1-MEK1 to endoplasmic reticulum forming a macromolecular complex that compartmentalizes MAPK signaling. Cell Mol Life Sci 2012; 69:3881-93. [PMID: 22752157 PMCID: PMC11114894 DOI: 10.1007/s00018-012-1056-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 05/16/2012] [Accepted: 06/11/2012] [Indexed: 12/30/2022]
Abstract
The spatial and temporal regulation of intracellular signaling is determined by the spatial and temporal organization of complexes assembled on scaffold proteins, which can be modulated by their interactions with additional proteins as well as subcellular localization. The scaffold KSR1 protein interacts with MAPK forming a complex that conveys a differential signaling in response to growth factors. The aim of this work is to determine the unknown mechanism by which VRK2A downregulates MAPK signaling. We have characterized the multiprotein complex formed by KSR1 and the Ser-Thr kinase VRK2A. VRK2A is a protein bound to the endoplasmic reticulum (ER) and retains a fraction of KSR1 complexes on the surface of this organelle. Both proteins, VRK2A and KSR1, directly interact by their respective C-terminal regions. In addition, MEK1 is also incorporated in the basal complex. MEK1 independently interacts with the CA5 region of KSR1 and with the N-terminus of VRK2A. Thus, VRK2A can form a high molecular size (600-1,000 kDa) stable complex with both MEK1 and KSR1. Knockdown of VRK2A resulted in disassembly of these high molecular size complexes. Overexpression of VRK2A increased the amount of KSR1 in the particulate fraction and prevented the incorporation of ERK1/2 into the complex after stimulation with EGF. Neither VRK2A nor KSR1 interact with the VHR, MKP1, MKP2, or MKP3 phosphatases. The KSR1 complex assembled and retained by VRK2A in the ER can have a modulatory effect on the signal mediated by MAPK, thus locally affecting the magnitude of its responses, and can explain differential responses depending on cell type.
Collapse
Affiliation(s)
- Isabel F. Fernández
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Luis G. Pérez-Rivas
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Malaga, Spain
- Laboratorio de Oncología Molecular, Fundación IMABIS, Hospital Clínico Universitario Virgen de la Victoria, Malaga, Spain
| | - Sandra Blanco
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Adrián A. Castillo-Dominguez
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Malaga, Spain
- Laboratorio de Oncología Molecular, Fundación IMABIS, Hospital Clínico Universitario Virgen de la Victoria, Malaga, Spain
| | - José Lozano
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Malaga, Spain
- Laboratorio de Oncología Molecular, Fundación IMABIS, Hospital Clínico Universitario Virgen de la Victoria, Malaga, Spain
| | - Pedro A. Lazo
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| |
Collapse
|
25
|
Increased BRAF heterodimerization is the common pathogenic mechanism for noonan syndrome-associated RAF1 mutants. Mol Cell Biol 2012; 32:3872-90. [PMID: 22826437 DOI: 10.1128/mcb.00751-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Noonan syndrome (NS) is a relatively common autosomal dominant disorder characterized by congenital heart defects, short stature, and facial dysmorphia. NS is caused by germ line mutations in several components of the RAS-RAF-MEK-extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway, including both kinase-activating and kinase-impaired alleles of RAF1 (∼3 to 5%), which encodes a serine-threonine kinase for MEK1/2. To investigate how kinase-impaired RAF1 mutants cause NS, we generated knock-in mice expressing Raf1(D486N). Raf1(D486N/+) (here D486N/+) female mice exhibited a mild growth defect. Male and female D486N/D486N mice developed concentric cardiac hypertrophy and incompletely penetrant, but severe, growth defects. Remarkably, Mek/Erk activation was enhanced in Raf1(D486N)-expressing cells compared with controls. RAF1(D486N), as well as other kinase-impaired RAF1 mutants, showed increased heterodimerization with BRAF, which was necessary and sufficient to promote increased MEK/ERK activation. Furthermore, kinase-activating RAF1 mutants also required heterodimerization to enhance MEK/ERK activation. Our results suggest that an increased heterodimerization ability is the common pathogenic mechanism for NS-associated RAF1 mutations.
Collapse
|
26
|
Distinct requirement for an intact dimer interface in wild-type, V600E and kinase-dead B-Raf signalling. EMBO J 2012; 31:2629-47. [PMID: 22510884 DOI: 10.1038/emboj.2012.100] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 03/23/2012] [Indexed: 12/11/2022] Open
Abstract
The dimerisation of Raf kinases involves a central cluster within the kinase domain, the dimer interface (DIF). Yet, the importance of the DIF for the signalling potential of wild-type B-Raf (B-Raf(wt)) and its oncogenic counterparts remains unknown. Here, we show that the DIF plays a pivotal role for the activity of B-Raf(wt) and several of its gain-of-function (g-o-f) mutants. In contrast, the B-Raf(V600E), B-Raf(insT) and B-Raf(G469A) oncoproteins are remarkably resistant to mutations in the DIF. However, compared with B-Raf(wt), B-Raf(V600E) displays extended protomer contacts, increased homodimerisation and incorporation into larger protein complexes. In contrast, B-Raf(wt) and Raf-1(wt) mediated signalling triggered by oncogenic Ras as well as the paradoxical activation of Raf-1 by kinase-inactivated B-Raf require an intact DIF. Surprisingly, the B-Raf DIF is not required for dimerisation between Raf-1 and B-Raf, which was inactivated by the D594A mutation, sorafenib or PLX4720. This suggests that paradoxical MEK/ERK activation represents a two-step mechanism consisting of dimerisation and DIF-dependent transactivation. Our data further implicate the Raf DIF as a potential target against Ras-driven Raf-mediated (paradoxical) ERK activation.
Collapse
|
27
|
Frese KK, Neesse A, Cook N, Bapiro TE, Lolkema MP, Jodrell DI, Tuveson DA. nab-Paclitaxel potentiates gemcitabine activity by reducing cytidine deaminase levels in a mouse model of pancreatic cancer. Cancer Discov 2012; 2:260-269. [PMID: 22585996 PMCID: PMC4866937 DOI: 10.1158/2159-8290.cd-11-0242] [Citation(s) in RCA: 332] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
UNLABELLED Nanoparticle albumin-bound (nab)-paclitaxel, an albumin-stabilized paclitaxel formulation, demonstrates clinical activity when administered in combination with gemcitabine in patients with metastatic pancreatic ductal adenocarcinoma (PDA). The limited availability of patient tissue and exquisite sensitivity of xenografts to chemotherapeutics have limited our ability to address the mechanistic basis of this treatment regimen. Here, we used a mouse model of PDA to show that the coadministration of nab-paclitaxel and gemcitabine uniquely demonstrates evidence of tumor regression. Combination treatment increases intratumoral gemcitabine levels attributable to a marked decrease in the primary gemcitabine metabolizing enzyme, cytidine deaminase. Correspondingly, paclitaxel reduced the levels of cytidine deaminase protein in cultured cells through reactive oxygen species-mediated degradation, resulting in the increased stabilization of gemcitabine. Our findings support the concept that suboptimal intratumoral concentrations of gemcitabine represent a crucial mechanism of therapeutic resistance in PDA and highlight the advantages of genetically engineered mouse models in preclinical therapeutic trials. SIGNIFICANCE This study provides mechanistic insight into the clinical cooperation observed between gemcitabine and nab-paclitaxel in the treatment of pancreatic cancer.
Collapse
Affiliation(s)
- Kristopher K. Frese
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
| | - Albrecht Neesse
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
- Department of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Baldingerstr, 35043 Marburg, Germany
| | - Natalie Cook
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
- Department of Oncology, University of Cambridge, Cambridge, UK
| | - Tashinga E. Bapiro
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
- Department of Oncology, University of Cambridge, Cambridge, UK
| | - Martijn P. Lolkema
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
- Department of Medical Oncology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Duncan I. Jodrell
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
- Department of Oncology, University of Cambridge, Cambridge, UK
| | - David A. Tuveson
- Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge, UK
- Department of Oncology, University of Cambridge, Cambridge, UK
| |
Collapse
|
28
|
Matsuda Y, Fukumoto M. Sorafenib: complexities of Raf-dependent and Raf-independent signaling are now unveiled. Med Mol Morphol 2011; 44:183-9. [PMID: 22179180 DOI: 10.1007/s00795-011-0558-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 07/15/2011] [Indexed: 12/13/2022]
Abstract
Hepatocellular carcinoma (HCC) is the most common primary cancer worldwide. The only current drug available for clinical treatment of HCC is sorafenib, which inhibits multiple signaling kinases including Raf family members, platelet-derived growth factor receptor, vascular endothelial growth factor receptors 1 and 2, c-Kit, and Fms-like tyrosine kinase 3. Many studies have revealed that the mechanism underlying the antitumor effect of sorafenib is complex. Because sorafenib inhibits C-Raf more potently than B-Raf, the therapeutic efficacy of sorafenib is strongly influenced by the relative expression and activity of B-Raf and C-Raf and the complex interactions between these factors. Moreover, Rafindependent signaling mechanisms have recently emerged as important pathways of sorafenib-induced cell death. Basic research studies have suggested that using sorafenib as part of a combination therapy may improve its effect, although this has yet to be confirmed by clinical evidence. Further studies of the functional mechanism of sorafenib are required to advance the development of targeted therapy for HCC. To aid future work on sorafenib, we here review the current literature pertaining to sorafenib signaling and its clinical efficacy in both monotherapy and combination therapy.
Collapse
Affiliation(s)
- Yasunobu Matsuda
- Department of Medical Technology, Niigata University Graduate School of Health Sciences, Asahimachi-dori, Niigata, Japan.
| | | |
Collapse
|
29
|
Patricelli MP, Nomanbhoy TK, Wu J, Brown H, Zhou D, Zhang J, Jagannathan S, Aban A, Okerberg E, Herring C, Nordin B, Weissig H, Yang Q, Lee JD, Gray NS, Kozarich JW. In situ kinase profiling reveals functionally relevant properties of native kinases. ACTA ACUST UNITED AC 2011; 18:699-710. [PMID: 21700206 DOI: 10.1016/j.chembiol.2011.04.011] [Citation(s) in RCA: 269] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 03/21/2011] [Accepted: 04/04/2011] [Indexed: 12/20/2022]
Abstract
Protein kinases are intensely studied mediators of cellular signaling, yet important questions remain regarding their regulation and in vivo properties. Here, we use a probe-based chemoprotemics platform to profile several well studied kinase inhibitors against >200 kinases in native cell proteomes and reveal biological targets for some of these inhibitors. Several striking differences were identified between native and recombinant kinase inhibitory profiles, in particular, for the Raf kinases. The native kinase binding profiles presented here closely mirror the cellular activity of these inhibitors, even when the inhibition profiles differ dramatically from recombinant assay results. Additionally, Raf activation events could be detected on live cell treatment with inhibitors. These studies highlight the complexities of protein kinase behavior in the cellular context and demonstrate that profiling with only recombinant/purified enzymes can be misleading.
Collapse
|
30
|
Strong negative feedback from Erk to Raf confers robustness to MAPK signalling. Mol Syst Biol 2011; 7:489. [PMID: 21613978 PMCID: PMC3130559 DOI: 10.1038/msb.2011.27] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 04/14/2011] [Indexed: 12/23/2022] Open
Abstract
This study shows that MAPK signalling is robust against protein level changes due to a strong negative feedback from Erk to Raf. Surprisingly, robustness is provided through a fast post-translational mechanism although variation of Erk levels occurs on a timescale of days. MAPK signalling is robust against variation in protein level. Robustness is mediated by a negative feedback to Raf. Loss of negative feedback due to mutation in B-Raf opens the door for targeted intervention.
Protein levels within signal transduction pathways vary strongly from cell to cell. For example, it has been reported that concentrations of the last kinase within the MAPK signalling module, Erk, varies about four-fold between clonal cells under the same conditions. In the present study, we analysed how signalling pathways can still process information quantitatively despite strong heterogeneity in protein levels. Mathematical analysis of isolated phosphorylation–dephosphorylation cycles predicts that phosphorylation of a signalling molecule is proportional to the protein concentration. We systematically perturbed the protein levels of Erk in human cell lines by siRNA. We found that the steady-state phosphorylation of Erk is very robust against perturbations of Erk protein level, suggesting that there are mechanisms that provide robustness to the pathway against protein fluctuations. Using mathematical modelling, we identified three potential mechanisms that may provide robustness against fluctuating protein levels: 1. Kinetic effects (saturation of the activating kinase Mek), 2. Transcriptional negative feedbacks, 3. Negative feedbacks on the post-translational level. By experimental analysis of the systems, which included analysis of Erk phosphorylation under Mek overexpression, measuring transcript levels of negative feedback regulators, and application of generic inhibitors of transcription and translation, we could exclude kinetic effects and transcriptional negative feedback as mechanisms of robustness. By analysing a panel of cell lines, we found that cells are robust as long as the signal passes through Raf-1. In contrast, cells where the pathway is activated by a mutation in B-Raf lose robustness. Detailed molecular analysis of the system shows that a single post-translational feedback to Raf mediates robustness. Thus, robustness is provided through a fast post-translational mechanism although variation of Erk levels occurs on a timescale of days. Protein levels within signal transduction pathways vary strongly from cell to cell. Here, we analysed how signalling pathways can still process information quantitatively despite strong heterogeneity in protein levels. We systematically perturbed the protein levels of Erk, the terminal kinase in the MAPK signalling pathway in a panel of human cell lines. We found that the steady-state phosphorylation of Erk is very robust against perturbations of Erk protein level. Although a multitude of mechanisms exist that may provide robustness against fluctuating protein levels, we found that one single feedback from Erk to Raf-1 accounts for the observed robustness. Surprisingly, robustness is provided through a fast post-translational mechanism although variation of Erk levels occurs on a timescale of days.
Collapse
|
31
|
Sorafenib and dacarbazine as first-line therapy for advanced melanoma: phase I and open-label phase II studies. Br J Cancer 2011; 105:353-9. [PMID: 21750549 PMCID: PMC3172912 DOI: 10.1038/bjc.2011.257] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Method: The safety of oral sorafenib up to a maximum protocol-specified dose combined with dacarbazine in patients with metastatic, histologically confirmed melanoma was investigated in a phase I dose-escalation study and the activity of the combination was explored in an open-label phase II study. Results: In the phase I study, three patients were treated with sorafenib 200 mg twice daily (b.i.d.) plus 1000 mg m−2 dacarbazine on day 1 of a 21-day cycle and 15 patients had the sorafenib dose escalated to 400 mg b.i.d. without reaching the maximum tolerated dose of the combination. In the phase II study (n=83), the overall response rate was 12% (95% CI: 6, 21): one complete and nine partial, with median response duration of 46.7 weeks. Stable disease was the best response in 37% median duration was 13.3 weeks. Median overall survival (OS) was 37.0 weeks (95% CI: 33.9, 46.0). Conclusion: Oral sorafenib combined with dacarbazine had acceptable toxicity and some antineoplastic activity against metastatic melanoma.
Collapse
|
32
|
|
33
|
Oncogene-induced Nrf2 transcription promotes ROS detoxification and tumorigenesis. Nature 2011; 475:106-9. [PMID: 21734707 PMCID: PMC3404470 DOI: 10.1038/nature10189] [Citation(s) in RCA: 1656] [Impact Index Per Article: 127.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Accepted: 05/12/2011] [Indexed: 12/19/2022]
Abstract
Reactive oxygen species (ROS) are mutagenic and may thereby promote cancer1. Normally, ROS levels are tightly controlled by an inducible antioxidant program that responds to cellular stressors and is predominantly regulated by the transcription factor Nrf2 and its repressor protein Keap12-5. In contrast to the acute physiological regulation of Nrf2, in neoplasia there is evidence for increased basal activation of Nrf2. Indeed, somatic mutations that disrupt the Nrf2-Keap1 interaction to stabilize Nrf2 and increase the constitutive transcription of Nrf2 target genes were recently identified, suggesting that enhanced ROS detoxification and additional Nrf2 functions may in fact be pro-tumorigenic6. Here, we investigated ROS metabolism in primary murine cells following the expression of endogenous oncogenic alleles of K-Ras, B-Raf and Myc, and find that ROS are actively suppressed by these oncogenes. K-RasG12D, B-RafV619E and MycERT2 each increased the transcription of Nrf2 to stably elevate the basal Nrf2 antioxidant program and thereby lower intracellular ROS and confer a more reduced intracellular environment. Oncogene-directed increased expression of Nrf2 is a novel mechanism for the activation of the Nrf2 antioxidant program, and is evident in primary cells and tissues of mice expressing K-RasG12D and B-RafV619E, and in human pancreatic cancer. Furthermore, genetic targeting of the Nrf2 pathway impairs K-RasG12D-induced proliferation and tumorigenesis in vivo. Thus, the Nrf2 antioxidant and cellular detoxification program represents a previously unappreciated mediator of oncogenesis.
Collapse
|
34
|
Wang H, Daouti S, Li WH, Wen Y, Rizzo C, Higgins B, Packman K, Rosen N, Boylan JF, Heimbrook D, Niu H. Identification of the MEK1(F129L) activating mutation as a potential mechanism of acquired resistance to MEK inhibition in human cancers carrying the B-RafV600E mutation. Cancer Res 2011; 71:5535-45. [PMID: 21705440 DOI: 10.1158/0008-5472.can-10-4351] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although targeting the Ras/Raf/MEK pathway remains a promising anticancer strategy, mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitors in clinical development are likely to be limited in their ability to produce durable clinical responses due to the emergence of acquired drug resistance. To identify potential mechanisms of such resistance, we established MEK inhibitor-resistant clones of human HT-29 colon cancer cells (HT-29R cells) that harbor the B-RafV600E mutation. HT-29R cells were specifically resistant to MEK inhibition in vitro and in vivo, with drug-induced elevation of MEK/ERK and their downstream targets primarily accountable for drug resistance. We identified MEK1(F129L) mutation as a molecular mechanism responsible for MEK/ERK pathway activation. In an isogenic cell system that extended these findings into other cancer cell lines, the MEK1(F129L) mutant exhibited higher intrinsic kinase activity than wild-type MEK1 [MEK1(WT)], leading to potent activation of ERK and downstream targets. The MEK1(F129L) mutation also strengthened binding to c-Raf, suggesting an underlying mechanism of higher intrinsic kinase activity. Notably, the combined use of Raf and MEK inhibitors overcame the observed drug resistance and exhibited greater synergy in HT-29R cells than the drug-sensitive HT-29 parental cells. Overall, our findings suggested that mutations in MEK1 can lead to acquired resistance in patients treated with MEK inhibitors and that a combined inhibition of Raf and MEK may be potentially useful as a strategy to bypass or prevent drug resistance in the clinic.
Collapse
Affiliation(s)
- Huisheng Wang
- Discovery Oncology, Hoffmann-La Roche Inc., Nutley, New Jersey 07110, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Sheen JH, Zoncu R, Kim D, Sabatini DM. Defective regulation of autophagy upon leucine deprivation reveals a targetable liability of human melanoma cells in vitro and in vivo. Cancer Cell 2011; 19:613-28. [PMID: 21575862 PMCID: PMC3115736 DOI: 10.1016/j.ccr.2011.03.012] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 08/10/2010] [Accepted: 03/15/2011] [Indexed: 02/08/2023]
Abstract
Autophagy is of increasing interest as a target for cancer therapy. We find that leucine deprivation causes the caspase-dependent apoptotic death of melanoma cells because it fails to appropriately activate autophagy. Hyperactivation of the RAS-MEK pathway, which is common in melanoma, prevents leucine deprivation from inhibiting mTORC1, the main repressor of autophagy under nutrient-rich conditions. In an in vivo tumor xenograft model, the combination of a leucine-free diet and an autophagy inhibitor synergistically suppresses the growth of human melanoma tumors and triggers widespread apoptosis of the cancer cells. Together, our study represents proof of principle that anticancer effects can be obtained with a combination of autophagy inhibition and strategies to deprive tumors of leucine.
Collapse
Affiliation(s)
- Joon-Ho Sheen
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | | | | | | |
Collapse
|
36
|
Abstract
Raf are conserved, ubiquitous serine/protein kinases discovered as the cellular elements hijacked by transforming retroviruses. The three mammalian RAF proteins (A, B and CRAF) can be activated by the human oncogene RAS, downstream from which they exert both kinase-dependent and kinase-independent, tumor-promoting functions. The kinase-dependent functions are mediated chiefly by the MEK/ERK pathway, whose activation is associated with proliferation in a broad range of human tumors. Almost 10 years ago, activating BRAF mutations were discovered in a subset of human tumors, and in the past year treatment with small-molecule RAF inhibitors has yielded unprecedented response rates in melanoma patients. Thus, Raf qualifies as an excellent molecular target for anticancer therapy. This review focuses on the role of BRAF and CRAF in different aspects of carcinogenesis, on the success of molecular therapies targeting Raf and the challenges they present.
Collapse
|
37
|
Karreth FA, Frese KK, DeNicola GM, Baccarini M, Tuveson DA. C-Raf is required for the initiation of lung cancer by K-Ras(G12D). Cancer Discov 2011; 1:128-36. [PMID: 22043453 DOI: 10.1158/2159-8290.cd-10-0044] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Ras/Raf/MEK/ERK (extracellular signal-regulated kinase) pathway is primarily responsible for mitogenesis in metazoans, and mutational activation of this pathway is common in cancer. A variety of selective chemical inhibitors directed against the mitogen-activated protein kinase pathway are now available for clinical investigation and thus the determination of the importance of each of the kinases in oncogenesis is paramount. We investigated the role of two Raf kinases, B-Raf and C-Raf, in Ras oncogenesis, and found that although B-Raf and C-Raf have overlapping functions in primary mesenchymal cells, C-Raf but not B-Raf is required for the proliferative effects of K-Ras(G12D) in primary epithelial cells. Furthermore, in a lung cancer mouse model, C-Raf is essential for tumor initiation by oncogenic K-Ras(G12D), whereas B-Raf is dispensable for this process. Our findings reveal that K-Ras(G12D) elicits its oncogenic effects primarily through C-Raf and suggest that selective C-Raf inhibition could be explored as a therapeutic strategy for K-Ras-dependent cancers.
Collapse
Affiliation(s)
- Florian A Karreth
- Li Ka Shing Centre, Cambridge Research Institute, Cancer Research UK, Cambridge, United Kingdom
| | | | | | | | | |
Collapse
|
38
|
Mukherjee R, McGuinness DH, McCall P, Underwood MA, Seywright M, Orange C, Edwards J. Upregulation of MAPK pathway is associated with survival in castrate-resistant prostate cancer. Br J Cancer 2011; 104:1920-8. [PMID: 21559022 PMCID: PMC3111196 DOI: 10.1038/bjc.2011.163] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background: Recent evidence has implicated the MAP kinase (MAPK) pathway with the development of castrate-resistant prostate cancer (CRPC). We have previously reported gene amplification of critical members of this pathway with the development of castrate-resistant disease. In addition, we have shown that rising Raf-1 expression, with the development of CRPC, influences time to biochemical relapse. We therefore sought to further analyse the role of both Raf-1 and its downstream target MAPK in the molecular pathogenesis of CRPC. Methods: Protein expression of Raf-1 and MAPK, including their activation status, was analysed using immunohistochemistry in a database of 65 paired tumour specimens obtained before and after the development of CRPC and correlated with other members of the pathway. Results: Patients whose nuclear expression of MAPK rose with the development of CRPC had a significantly shorter median time to death following biochemical relapse (1.40 vs 3.00 years, P=0.0255) as well as reduced disease-specific survival when compared with those whose expression fell or remained unchanged (1.16 vs 2.62 years, P=0.0005). Significant correlations were observed between protein expression of Raf-1 and MAPK with the type 1 receptor tyrosine kinases, Her2 and epidermal growth factor receptor, as well as the transcription factor AP-1 in CRPC tumours. Conclusion: We conclude that the Her2/Raf-1/MAPK/AP-1 axis may promote the development of CRPC, leading to early relapse, and reduced disease-specific survival. In addition, members of the pathway may act as novel therapeutic and/or diagnostic targets for prostate cancer.
Collapse
Affiliation(s)
- R Mukherjee
- College of Medical, Veterinary and Life Sciences, Institute of Cancer, McGregor Building, Glasgow Western Infirmary, Glasgow G11 6NT, UK
| | | | | | | | | | | | | |
Collapse
|
39
|
Little AS, Balmanno K, Sale MJ, Newman S, Dry JR, Hampson M, Edwards PAW, Smith PD, Cook SJ. Amplification of the driving oncogene, KRAS or BRAF, underpins acquired resistance to MEK1/2 inhibitors in colorectal cancer cells. Sci Signal 2011; 4:ra17. [PMID: 21447798 DOI: 10.1126/scisignal.2001752] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The acquisition of resistance to protein kinase inhibitors is a growing problem in cancer treatment. We modeled acquired resistance to the MEK1/2 (mitogen-activated or extracellular signal-regulated protein kinase kinases 1 and 2) inhibitor selumetinib (AZD6244) in colorectal cancer cell lines harboring mutations in BRAF (COLO205 and HT29 lines) or KRAS (HCT116 and LoVo lines). AZD6244-resistant derivatives were refractory to AZD6244-induced cell cycle arrest and death and exhibited a marked increase in ERK1/2 (extracellular signal-regulated kinases 1 and 2) pathway signaling and cyclin D1 abundance when assessed in the absence of inhibitor. Genomic sequencing revealed no acquired mutations in MEK1 or MEK2, the primary target of AZD6244. Rather, resistant lines showed a marked up-regulation of their respective driving oncogenes, BRAF(600E) or KRAS(13D), due to intrachromosomal amplification. Inhibition of BRAF reversed resistance to AZD6244 in COLO205 cells, which suggested that combined inhibition of MEK1/2 and BRAF may reduce the likelihood of acquired resistance in tumors with BRAF(600E). Knockdown of KRAS reversed AZD6244 resistance in HCT116 cells as well as reduced the activation of ERK1/2 and protein kinase B; however, the combined inhibition of ERK1/2 and phosphatidylinositol 3-kinase signaling had little effect on AZD6244 resistance, suggesting that additional KRAS effector pathways contribute to this process. Microarray analysis identified increased expression of an 18-gene signature previously identified as reflecting MEK1/2 pathway output in resistant cells. Thus, amplification of the driving oncogene (BRAF(600E) or KRAS(13D)) can drive acquired resistance to MEK1/2 inhibitors by increasing signaling through the ERK1/2 pathway. However, up-regulation of KRAS(13D) leads to activation of multiple KRAS effector pathways, underlining the therapeutic challenge posed by KRAS mutations. These results may have implications for the use of combination therapies.
Collapse
Affiliation(s)
- Annette S Little
- Laboratory of Molecular Signalling, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Matallanas D, Birtwistle M, Romano D, Zebisch A, Rauch J, von Kriegsheim A, Kolch W. Raf family kinases: old dogs have learned new tricks. Genes Cancer 2011; 2:232-60. [PMID: 21779496 PMCID: PMC3128629 DOI: 10.1177/1947601911407323] [Citation(s) in RCA: 272] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
First identified in the early 1980s as retroviral oncogenes, the Raf proteins have been the objects of intense research. The discoveries 10 years later that the Raf family members (Raf-1, B-Raf, and A-Raf) are bona fide Ras effectors and upstream activators of the ubiquitous ERK pathway increased the interest in these proteins primarily because of the central role that this cascade plays in cancer development. The important role of Raf in cancer was corroborated in 2002 with the discovery of B-Raf genetic mutations in a large number of tumors. This led to intensified drug development efforts to target Raf signaling in cancer. This work yielded not only recent clinical successes but also surprising insights into the regulation of Raf proteins by homodimerization and heterodimerization. Surprising insights also came from the hunt for new Raf targets. Although MEK remains the only widely accepted Raf substrate, new kinase-independent roles for Raf proteins have emerged. These include the regulation of apoptosis by suppressing the activity of the proapoptotic kinases, ASK1 and MST2, and the regulation of cell motility and differentiation by controlling the activity of Rok-α. In this review, we discuss the regulation of Raf proteins and their role in cancer, with special focus on the interacting proteins that modulate Raf signaling. We also describe the new pathways controlled by Raf proteins and summarize the successes and failures in the development of efficient anticancer therapies targeting Raf. Finally, we also argue for the necessity of more systemic approaches to obtain a better understanding of how the Ras-Raf signaling network generates biological specificity.
Collapse
Affiliation(s)
- David Matallanas
- Systems Biology Ireland, University College Dublin, Dublin, Ireland
| | | | | | | | | | | | | |
Collapse
|
41
|
Udell CM, Rajakulendran T, Sicheri F, Therrien M. Mechanistic principles of RAF kinase signaling. Cell Mol Life Sci 2011; 68:553-65. [PMID: 20820846 PMCID: PMC11114552 DOI: 10.1007/s00018-010-0520-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 08/24/2010] [Accepted: 08/25/2010] [Indexed: 12/19/2022]
Abstract
The RAF family of kinases are key components acting downstream of receptor tyrosine kinases and cells employ several distinct mechanisms to strictly control their activity. RAF transitions from an inactive state, where the N-terminal regulatory region binds intramolecularly to the C-terminal kinase domain, to an open state capable of executing the phosphoryl transfer reaction. This transition involves changes both within and between the protein domains in RAF. Many different proteins regulate the transition between inactive and active states of RAF, including RAS and KSR, which are arguably the two most prominent regulators of RAF function. Recent developments have added several new twists to our understanding of RAF regulation. Among others, dimerization of the RAF kinase domain is emerging as a crucial step in the RAF activation process. The multitude of regulatory protein-protein interactions involving RAF remains a largely untapped area for therapeutic applications.
Collapse
Affiliation(s)
- Christian M. Udell
- Laboratory of Intracellular Signaling, Département de pathologie et de biologie cellulaire, Institute for Research in Immunology and Cancer, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC H3C 3J7 Canada
| | - Thanashan Rajakulendran
- Centre for Systems Biology, Samuel Lunenfeld Research Institute, Toronto, ON M5G 1X5 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8 Canada
| | - Frank Sicheri
- Centre for Systems Biology, Samuel Lunenfeld Research Institute, Toronto, ON M5G 1X5 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8 Canada
| | - Marc Therrien
- Laboratory of Intracellular Signaling, Département de pathologie et de biologie cellulaire, Institute for Research in Immunology and Cancer, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montreal, QC H3C 3J7 Canada
| |
Collapse
|
42
|
Ott PA, Hamilton A, Min C, Safarzadeh-Amiri S, Goldberg L, Yoon J, Yee H, Buckley M, Christos PJ, Wright JJ, Polsky D, Osman I, Liebes L, Pavlick AC. A phase II trial of sorafenib in metastatic melanoma with tissue correlates. PLoS One 2010; 5:e15588. [PMID: 21206909 PMCID: PMC3012061 DOI: 10.1371/journal.pone.0015588] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 11/13/2010] [Indexed: 01/07/2023] Open
Abstract
Background Sorafenib monotherapy in patients with metastatic melanoma was explored in this multi-institutional phase II study. In correlative studies the impact of sorafenib on cyclin D1 and Ki67 was assessed. Methodology/Principal Findings Thirty-six patients treatment-naïve advanced melanoma patients received sorafenib 400 mg p.o. twice daily continuously. Tumor BRAFV600E mutational status was determined by routine DNA sequencing and mutation-specific PCR (MSPCR). Immunohistochemistry (IHC) staining for cyclin D1 and Ki67 was performed on available pre- and post treatment tumor samples. The main toxicities included diarrhea, alopecia, rash, mucositis, nausea, hand-foot syndrome, and intestinal perforation. One patient had a RECIST partial response (PR) lasting 175 days. Three patients experienced stable disease (SD) with a mean duration of 37 weeks. Routine BRAFV600E sequencing yielded 27 wild-type (wt) and 6 mutant tumors, whereas MSPCR identified 12 wt and 18 mutant tumors. No correlation was seen between BRAFV600E mutational status and clinical activity. No significant changes in expression of cyclin D1 or Ki67 with sorafenib treatment were demonstrable in the 15 patients with pre-and post-treatment tumor samples. Conclusions/Significance Sorafenib monotherapy has limited activity in advanced melanoma patients. BRAFV600E mutational status of the tumor was not associated with clinical activity and no significant effect of sorafenib on cyclin D1 or Ki67 was seen, suggesting that sorafenib is not an effective BRAF inhibitor or that additional signaling pathways are equally important in the patients who benefit from sorafenib. Trial registration Clinical Trials.gov NCT00119249
Collapse
Affiliation(s)
- Patrick A. Ott
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
| | - Anne Hamilton
- Sydney Cancer Centre, Royal Prince Alfred Hospital, Sydney, Australia
- Sydney Melanoma Unit and University of Sydney, Sydney, Australia
| | - Christina Min
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
| | - Sara Safarzadeh-Amiri
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
| | - Lauren Goldberg
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
| | - Joanne Yoon
- Department of Dermatology, New York University School of Medicine, New York, New York, United States of America
| | - Herman Yee
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - Michael Buckley
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
| | - Paul J. Christos
- Division of Biostatistics and Epidemiology, Weill Cornell Medical College, New York, New York, United States of America
| | - John J. Wright
- Investigational Drug Branch, National Cancer Institute, Bethesda, Maryland, United States of America
| | - David Polsky
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
- Department of Dermatology, New York University School of Medicine, New York, New York, United States of America
| | - Iman Osman
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
- Department of Dermatology, New York University School of Medicine, New York, New York, United States of America
| | - Leonard Liebes
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
| | - Anna C. Pavlick
- Department of Medical Oncology, New York University School of Medicine, New York, New York, United States of America
- Department of Dermatology, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
43
|
Johannessen CM, Boehm JS, Kim SY, Thomas SR, Wardwell L, Johnson LA, Emery CM, Stransky N, Cogdill AP, Barretina J, Caponigro G, Hieronymus H, Murray RR, Salehi-Ashtiani K, Hill DE, Vidal M, Zhao JJ, Yang X, Alkan O, Kim S, Harris JL, Wilson CJ, Myer VE, Finan PM, Root DE, Roberts TM, Golub T, Flaherty KT, Dummer R, Weber BL, Sellers WR, Schlegel R, Wargo JA, Hahn WC, Garraway LA. COT drives resistance to RAF inhibition through MAP kinase pathway reactivation. Nature 2010; 468:968-72. [PMID: 21107320 PMCID: PMC3058384 DOI: 10.1038/nature09627] [Citation(s) in RCA: 1145] [Impact Index Per Article: 81.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 10/25/2010] [Indexed: 12/14/2022]
Abstract
Oncogenic mutations in the serine/threonine kinase B-RAF (also known as BRAF) are found in 50-70% of malignant melanomas. Pre-clinical studies have demonstrated that the B-RAF(V600E) mutation predicts a dependency on the mitogen-activated protein kinase (MAPK) signalling cascade in melanoma-an observation that has been validated by the success of RAF and MEK inhibitors in clinical trials. However, clinical responses to targeted anticancer therapeutics are frequently confounded by de novo or acquired resistance. Identification of resistance mechanisms in a manner that elucidates alternative 'druggable' targets may inform effective long-term treatment strategies. Here we expressed ∼600 kinase and kinase-related open reading frames (ORFs) in parallel to interrogate resistance to a selective RAF kinase inhibitor. We identified MAP3K8 (the gene encoding COT/Tpl2) as a MAPK pathway agonist that drives resistance to RAF inhibition in B-RAF(V600E) cell lines. COT activates ERK primarily through MEK-dependent mechanisms that do not require RAF signalling. Moreover, COT expression is associated with de novo resistance in B-RAF(V600E) cultured cell lines and acquired resistance in melanoma cells and tissue obtained from relapsing patients following treatment with MEK or RAF inhibitors. We further identify combinatorial MAPK pathway inhibition or targeting of COT kinase activity as possible therapeutic strategies for reducing MAPK pathway activation in this setting. Together, these results provide new insights into resistance mechanisms involving the MAPK pathway and articulate an integrative approach through which high-throughput functional screens may inform the development of novel therapeutic strategies.
Collapse
Affiliation(s)
- Cory M Johannessen
- Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, Massachusetts 02142, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Wimmer R, Baccarini M. Partner exchange: protein-protein interactions in the Raf pathway. Trends Biochem Sci 2010; 35:660-8. [PMID: 20621483 DOI: 10.1016/j.tibs.2010.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/27/2010] [Accepted: 06/07/2010] [Indexed: 01/07/2023]
Abstract
The three-tiered Raf-MEK-ERK kinase module is activated downstream of Ras and has been traditionally linked to cellular proliferation. Mammals have three Raf, two Mek and two Erk genes. Recently, the analysis of protein-protein interactions in the pathway has begun to provide a rationale for the redundancy within each tier. New results show that the MEK-ERK-activating unit consists of Raf hetero- and homodimers; downstream of Raf, MEK1-MEK2 heterodimers and ERK dimers are required for temporal and spatial pathway regulation. Finally, C-Raf mediates pathway crosstalk downstream of Ras by directly binding to and inhibiting kinases engaged in other signaling cascades. Given the roles of these interactions in tumorigenesis, their study will provide new opportunities for molecule-based therapies that target the pathway.
Collapse
Affiliation(s)
- Reiner Wimmer
- University of Vienna, Center for Molecular Biology, Max F. Perutz Laboratories, Doktor-Bohr-Gasse 9, A-1030 Vienna, Austria
| | | |
Collapse
|
45
|
Calcineurin increases glucose activation of ERK1/2 by reversing negative feedback. Proc Natl Acad Sci U S A 2010; 107:22314-9. [PMID: 21135229 DOI: 10.1073/pnas.1016630108] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In pancreatic β cells, ERK1 and ERK2 participate in nutrient sensing, and their activities rise and fall as a function of glucose concentration over the physiologic range. Glucose metabolism triggers calcium influx and release of calcium from intracellular stores to activate ERK1/2. Calcium influx also activates the calcium-dependent phosphatase calcineurin, which is required for maximal ERK1/2 activation by glucose. Calcineurin controls insulin gene expression by ERK1/2-dependent and -independent mechanisms. Here, we show that, in β cells, glucose activates the ERK1/2 cascade primarily through B-Raf. Glucose activation of B-Raf, like that of ERK1/2, is calcineurin-sensitive. Calcineurin binds to B-Raf in both unstimulated and stimulated cells. We show that B-Raf is a calcineurin substrate; among calcineurin target residues on B-Raf is T401, a site of negative feedback phosphorylation by ERK1/2. Blocking calcineurin activity in β cells prevents dephosphorylation of B-Raf T401 and decreases B-Raf and ERK1/2 activities. We conclude that the major calcineurin-dependent event in glucose sensing by ERK1/2 is the activation of B-Raf.
Collapse
|
46
|
Matei D, Sill MW, Lankes HA, DeGeest K, Bristow RE, Mutch D, Yamada SD, Cohn D, Calvert V, Farley J, Petricoin EF, Birrer MJ. Activity of sorafenib in recurrent ovarian cancer and primary peritoneal carcinomatosis: a gynecologic oncology group trial. J Clin Oncol 2010; 29:69-75. [PMID: 21098323 DOI: 10.1200/jco.2009.26.7856] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE Sorafenib is a kinase inhibitor targeting Raf and other kinases (ie, vascular endothelial growth factor receptor [VEGFR], platelet-derived growth factor receptor [PDGFR], Flt3, and c-KIT). This study assessed its activity and tolerability in patients with recurrent ovarian cancer (OC) or primary peritoneal carcinomatosis (PPC). METHODS This open-label, multi-institutional, phase II study used a two-stage design. Eligible patients had persistent or recurrent OC/PPC after one to two prior cytotoxic regimens, and they experienced progression within 12 months of platinum-based therapy. Treatment consisted of sorafenib 400 mg orally twice per day. Primary end points were progression-free survival (PFS) at 6 months and toxicity by National Cancer Institute criteria. Secondary end points were tumor response and duration of PFS and overall survival. Biomarker analyses included measurement of ERK and b-Raf expression in tumors and phosphorylation of ERK (pERK) in peripheral-blood lymphocytes (PBLs) before and after 1 month of treatment. Results Seventy-three patients were enrolled, of which 71 were eligible. Fifty-nine eligible patients (83%) had measurable disease, and 12 (17%) had detectable disease. Significant grade 3 or 4 toxicities included the following: rash (n = 7), hand-foot syndrome (n = 9), metabolic (n = 10), GI (n = 3), cardiovascular (n = 2), and pulmonary (n = 2). Only patients with measurable disease were used to assess efficacy. Fourteen survived progression free for at least 6 months (24%; 90% CI, 15% to 35%). Two patients had partial responses (3.4%; 90% CI, 1% to 10%); 20 had stable disease; 30 had progressive disease; and seven could not have their tumor assessed. ERK and b-Raf were expressed in all tumors. Exploratory analyses indicated that pERK in post-treatment PBL specimens was associated with PFS. CONCLUSION Sorafenib has modest antitumor activity in patients with recurrent OC, but the activity was at the expense of substantial toxicity.
Collapse
Affiliation(s)
- Daniela Matei
- Indiana University School of Medicine, Division of Hematology-Oncology, RT-457, 535 Barnhill Dr, Indianapolis, IN 46202, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Cirit M, Wang CC, Haugh JM. Systematic quantification of negative feedback mechanisms in the extracellular signal-regulated kinase (ERK) signaling network. J Biol Chem 2010; 285:36736-44. [PMID: 20847054 PMCID: PMC2978602 DOI: 10.1074/jbc.m110.148759] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 08/20/2010] [Indexed: 12/28/2022] Open
Abstract
Cell responses are actuated by tightly controlled signal transduction pathways. Although the concept of an integrated signaling network replete with interpathway cross-talk and feedback regulation is broadly appreciated, kinetic data of the type needed to characterize such interactions in conjunction with mathematical models are lacking. In mammalian cells, the Ras/ERK pathway controls cell proliferation and other responses stimulated by growth factors, and several cross-talk and feedback mechanisms affecting its activation have been identified. In this work, we take a systematic approach to parse the magnitudes of multiple regulatory mechanisms that attenuate ERK activation through canonical (Ras-dependent) and non-canonical (PI3K-dependent) pathways. In addition to regulation of receptor and ligand levels, we consider three layers of ERK-dependent feedback: desensitization of Ras activation, negative regulation of MEK kinase (e.g. Raf) activities, and up-regulation of dual-specificity ERK phosphatases. Our results establish the second of these as the dominant mode of ERK self-regulation in mouse fibroblasts. We further demonstrate that kinetic models of signaling networks, trained on a sufficient diversity of quantitative data, can be reasonably comprehensive, accurate, and predictive in the dynamical sense.
Collapse
Affiliation(s)
- Murat Cirit
- From the Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695
| | - Chun-Chao Wang
- From the Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695
| | - Jason M. Haugh
- From the Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695
| |
Collapse
|
48
|
Down-regulation of TERE1/UBIAD1 activated Ras-MAPK signalling and induced cell proliferation. CELL BIOLOGY INTERNATIONAL REPORTS 2010; 17:e00005. [PMID: 23119142 PMCID: PMC3475436 DOI: 10.1042/cbr20100005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 09/21/2010] [Indexed: 12/21/2022]
Abstract
TERE1/UBIAD1 is involved in SCCD (Schnyder crystalline corneal dystrophy) and multiple human cancers. So far, the molecular mechanism of TERE1/UBIAD1 in tumourigenesis is unclear. Here, the expression levels of hTERT and TERE1/UBIAD1 in pathologically proven Chinese TCC (transitional cell carcinoma) samples were measured. It was found that decreased TERE1/UBIAD1 expression is closely related to both an increased hTERT expression and activation of Ras–MAPK signalling. Chemically modified TERE1 siRNA oligos were used to knock down TERE1 expression in human L02 cells. Cells transfected with TERE1 siRNA oligos underwent significant cell proliferation. When the levels of hTERT expression and ERK phosphorylation were measured, it was found that both of them increased in the above transfected cells, suggesting the activation of Ras–MAPK signalling. Addition of the MEK inhibitor U0126 into the transfected L02 cells described above inhibited ERK phosphorylation and hTERT expression. Our result is the initial demonstration that down-regulation of TERE1 activates Ras–MAPK signalling and induces subsequent cell proliferation. TERE1 might be a new negative regulator of Ras–MAPK signalling, which plays a pivotal role in the cell proliferation of multiple human cancers.
Collapse
Key Words
- GAPDH, human glyceraldehyde 3-phosphate dehydrogenase
- IHC, immunohistochemistry
- MAPK
- MAPK, mitogen-activated protein kinase
- MC, mock control
- MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
- NC, negative group
- SCCD, Schnyder crystalline corneal dystrophy
- SREBP, sterol response element binding protein
- TCC, transitional cell carcinoma
- TERE1/UBIAD1
- cell proliferation
- hTERT
- siRNA, small interfering RNA
Collapse
|
49
|
VRK2 inhibits mitogen-activated protein kinase signaling and inversely correlates with ErbB2 in human breast cancer. Mol Cell Biol 2010; 30:4687-97. [PMID: 20679487 DOI: 10.1128/mcb.01581-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The epidermal growth factor (EGF)-ErbB-mitogen-activated protein kinase (MAPK) transcription signaling pathway is altered in many types of carcinomas, and this pathway can be regulated by new protein-protein interactions. Vaccinia-related kinase (VRK) proteins are Ser-Thr kinases that regulate several signal transduction pathways. In this work, we study the effect of VRK2 on MAPK signaling using breast cancer as a model. High levels of VRK2 inhibit EGF and ErbB2 activation of transcription by the serum response element (SRE). This effect is also detected in response to H-Ras(G12V) or B-Raf(V600E) oncogenes and is accompanied by a reduction in phosphorylated extracellular signal-regulated kinase (ERK) levels, p90RSK levels, and SRE-dependent transcription. Furthermore, VRK2 knockdown has the opposite effect, increasing the transcriptional response to stimulation with EGF and leading to increased levels of ERK phosphorylation. The molecular mechanism lies between MAPK/ERK kinase (MEK) and ERK, since MEK remains phosphorylated while ERK phosphorylation is blocked by VRK2A. This inhibition of the ERK signaling pathway is a consequence of a direct protein-protein interaction between VRK2A, MEK, and kinase suppressor of Ras 1 (KSR1). Identification of new correlations in human cancer can lead to a better understanding of the biology of individual tumors. ErbB2 and VRK2 protein levels were inversely correlated in 136 cases of human breast carcinoma. In ErbB2(+) tumors, there is a significant reduction in the VRK2 level, suggesting a role for VRK2A in ErbB2-MAPK signaling. Thus, VRK2 downregulation in carcinomas permits signal transmission through the MEK-ERK pathway without affecting AKT signaling, causing a signal imbalance among pathways that contributes to the phenotype of breast cancer.
Collapse
|
50
|
Robubi A, Waldmann H, Rauh D. RAF Kinase Inhibitors in Cancer Treatment: Like a Bull in a China Shop? Chembiochem 2010; 11:1645-8. [DOI: 10.1002/cbic.201000348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|