1
|
Li Q, Li Z, Luo T, Shi H. Targeting the PI3K/AKT/mTOR and RAF/MEK/ERK pathways for cancer therapy. MOLECULAR BIOMEDICINE 2022; 3:47. [PMID: 36539659 PMCID: PMC9768098 DOI: 10.1186/s43556-022-00110-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/10/2022] [Indexed: 12/24/2022] Open
Abstract
The PI3K/AKT/mTOR and RAF/MEK/ERK pathways are commonly activated by mutations and chromosomal translocation in vital targets. The PI3K/AKT/mTOR signaling pathway is dysregulated in nearly all kinds of neoplasms, with the component in this pathway alternations. RAF/MEK/ERK signaling cascades are used to conduct signaling from the cell surface to the nucleus to mediate gene expression, cell cycle processes and apoptosis. RAS, B-Raf, PI3K, and PTEN are frequent upstream alternative sites. These mutations resulted in activated cell growth and downregulated cell apoptosis. The two pathways interact with each other to participate in tumorigenesis. PTEN alterations suppress RAF/MEK/ERK pathway activity via AKT phosphorylation and RAS inhibition. Several inhibitors targeting major components of these two pathways have been supported by the FDA. Dozens of agents in these two pathways have attracted great attention and have been assessed in clinical trials. The combination of small molecular inhibitors with traditional regimens has also been explored. Furthermore, dual inhibitors provide new insight into antitumor activity. This review will further comprehensively describe the genetic alterations in normal patients and tumor patients and discuss the role of targeted inhibitors in malignant neoplasm therapy. We hope this review will promote a comprehensive understanding of the role of the PI3K/AKT/mTOR and RAF/MEK/ERK signaling pathways in facilitating tumors and will help direct drug selection for tumor therapy.
Collapse
Affiliation(s)
- Qingfang Li
- grid.13291.380000 0001 0807 1581Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, West China Hospital, National Clinical Research Center for Geriatrics, Sichuan University, Chengdu, China
| | - Zhihui Li
- Department of Oncology, The General Hospital of Western Theater Command, Chengdu, PR China
| | - Ting Luo
- grid.13291.380000 0001 0807 1581Department of Breast, Cancer Center, West China Hospital, Sichuan University, 610041 Chengdu, P. R. China
| | - Huashan Shi
- grid.13291.380000 0001 0807 1581Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, 610041 Chengdu, P. R. China
| |
Collapse
|
2
|
Cordeiro HG, de Sousa Faria AV, Ferreira-Halder CV. Vemurafenib downmodulates aggressiveness mediators of colorectal cancer (CRC): Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP), Protein Tyrosine Phosphatase 1B (PTP1B) and Transforming Growth Factor β (TGFβ). Biol Chem 2021; 401:1063-1069. [PMID: 32229687 DOI: 10.1515/hsz-2020-0124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 03/17/2020] [Indexed: 12/11/2022]
Abstract
Colorectal Cancer (CRC) therapy confronts challenges as chemoresistance and side effects. Therefore, drugs with antitumor properties that downmodulate aggressiveness mediators are required. Studies have shown the relevance of Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP), Protein Tyrosine Phosphatase 1B (PTP1B), and Transforming Growth Factor β (TGFβ) in mediating proliferation, chemoresistance, and metastasis. In this study, we aimed to investigate the responsiveness of colorectal cancer lines (HT29 and HCT116) towards Vemurafenib and whether this treatment could modulate these aggressiveness mediators. Cytotoxicity Assays (MTT and Trypan Exclusion Test) were performed to evaluate the viability of HT29 and HCT116 cells treated with Vemurafenib. Western blotting was performed to analyze the amount and/or the activity of mediators (LMWPTP, PTP1B, TGFβ, SMAD3), and the immunoprecipitation was performed to evaluate LMWPTP activity. This study brought up novel aspects of Vemurafenib action in colorectal cancer, which can decrease the activity of protein tyrosine phosphatases (LMWPTP and PTP1B) and the TGFβ pathway, making them important in the CRC aggressiveness. By downmodulating colorectal cancer hallmarks, Vemurafenib appears as an interesting candidate for CRC therapeutic protocols.
Collapse
Affiliation(s)
- Helon Guimarães Cordeiro
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Monteiro Lobato Street 255, Campinas, 13083-862, SP, Brazil
| | - Alessandra Valéria de Sousa Faria
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Monteiro Lobato Street 255, Campinas, 13083-862, SP, Brazil
| | - Carmen Veríssima Ferreira-Halder
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Monteiro Lobato Street 255, Campinas, 13083-862, SP, Brazil
| |
Collapse
|
3
|
Deng L, Huang X, Dong C, Ren J. Simultaneously monitoring endogenous MAPK members in single living cells by multi-channel fluorescence correlation spectroscopy. Analyst 2021; 146:2581-2590. [PMID: 33899064 DOI: 10.1039/d1an00090j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mitogen-activated protein kinase (MAPK) pathway is a major module for cellular signal transduction. The dysregulation of the MAPK pathway has been involved in the pathogenesis of multiple diseases ranging from cancers to chronic inflammations. So far, we have not fully understood the influences of external factors and signaling networks on the MAPK pathway due to the lack of in situ methods for simultaneous detection of multiple kinases in the pathway in living cells. Herein, we present a new strategy for in situ and simultaneously monitoring MAPK pathway kinases in single living cells combining multi-channel fluorescence correlation spectroscopy (FCS) with affinity fluorescent probes. We chose rapidly growing fibrosarcoma kinase (RAF), mitogen-activated protein kinase (MEK), and extracellular signal-regulated kinase (ERK) as representative members in the MAPK pathway. We designed and synthesized three fluorescent affinity probes and experimental results demonstrated that the three probes specifically targeted endogenous BRAF, MEK1/2, and ERK1/2 in living cells. Based on the multi-channel FCS system, we studied the influences of biological substances, drugs and oxidative stress on the activities of endogenous MAPK kinases and the cross-talk between the MAPK and PI3K-mTOR pathways. We have found that serum, sorafenib, and hydrogen peroxide can regulate multiple MAPK kinases and the effects of external stimuli can transmit to the MAPK pathway; furthermore, we have observed that the MAPK pathway can be activated by modulating the PI3K-mTOR pathway. Our results illustrated the complexity of a cellular signal network and the necessity of in situ and simultaneous determination of biomolecules in living cells.
Collapse
Affiliation(s)
- Liyun Deng
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
| | - Xiangyi Huang
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
| | - Chaoqing Dong
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
| |
Collapse
|
4
|
Faria AVS, Fonseca EMB, Cordeiro HG, Clerici SP, Ferreira-Halder CV. Low molecular weight protein tyrosine phosphatase as signaling hub of cancer hallmarks. Cell Mol Life Sci 2021; 78:1263-1273. [PMID: 33052434 PMCID: PMC11073135 DOI: 10.1007/s00018-020-03657-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/21/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022]
Abstract
In the past decade, significant progress has been made in understanding the role of protein tyrosine phosphatase as a positive regulator of tumor progression. In this scenario, our group was one of the first to report the involvement of the low molecular weight protein tyrosine phosphatase (LMWPTP or ACP1) in the process of resistance and migration of tumor cells. Later, we and others demonstrated a positive correlation between the amount of this enzyme in human tumors and the poor prognosis. With this information in mind, we asked if LMWPTP contribution to metastasis, would it have an action beyond the primary tumor site. We know that the amount of this enzyme in the tumor cell correlates positively with the ability of cancer cells to interact with platelets, an indication that this enzyme is also important for the survival of these cells in the bloodstream. Here, we discuss several molecular aspects that support the idea of LMWPTP as a signaling hub of cancer hallmarks. Chemical and genetic modulation of LMWPTP proved to shut down signaling pathways associated with cancer aggressiveness. Therefore, advances in the development of LMWPTP inhibitors have great applicability in human diseases such as cancer.
Collapse
Affiliation(s)
- Alessandra V S Faria
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Emanuella Maria Barreto Fonseca
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
- Federal Institute of São Paulo, São Roque, São Paulo, Brazil
| | - Helon Guimarães Cordeiro
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
| | - Stefano Piatto Clerici
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
| | | |
Collapse
|
5
|
Shetty SS, Sharma M, Fonseca FP, Jayaram P, Tanwar AS, Kabekkodu SP, Kapaettu S, Radhakrishnan R. Signaling pathways promoting epithelial mesenchymal transition in oral submucous fibrosis and oral squamous cell carcinoma. JAPANESE DENTAL SCIENCE REVIEW 2020; 56:97-108. [PMID: 32874377 PMCID: PMC7452314 DOI: 10.1016/j.jdsr.2020.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/02/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023] Open
Abstract
Epithelial-mesenchymal transition (EMT) is a critical process that occurs during the embryonic development, wound healing, organ fibrosis and the onset of malignancy. Emerging evidence suggests that the EMT is involved in the invasion and metastasis of cancers. The inflammatory reaction antecedent to fibrosis in the onset of oral submucous fibrosis (OSF) and the role of EMT in its malignant transformation indicates a hitherto unexplored involvement of EMT. This review focuses on the role of EMT markers which are regulators of the EMT mediated complex network of molecular mechanisms involved in the pathogenesis of OSF and OSCC. Further the gene enrichment analysis and pathway analysis supports the association of the upregulated and downregulated genes in various EMT regulating pathways.
Collapse
Affiliation(s)
- Smitha Sammith Shetty
- Department of Oral Pathology, Faculty of Dentistry, Melaka Manipal Medical College, Manipal Academy of Higher Education, Manipal 576104, India
| | - Mohit Sharma
- Department of Oral Pathology, Sudha Rustagi College of Dental Sciences and Research, Faridabad 121004, India
| | - Felipe Paiva Fonseca
- Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Pradyumna Jayaram
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Ankit Singh Tanwar
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Shama Prasada Kabekkodu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Satyamoorthy Kapaettu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Raghu Radhakrishnan
- Department of Oral Pathology, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal 576104, India
- Corresponding author.
| |
Collapse
|
6
|
Abstract
RAS was identified as a human oncogene in the early 1980s and subsequently found to be mutated in nearly 30% of all human cancers. More importantly, RAS plays a central role in driving tumor development and maintenance. Despite decades of effort, there remain no FDA approved drugs that directly inhibit RAS. The prevalence of RAS mutations in cancer and the lack of effective anti-RAS therapies stem from RAS' core role in growth factor signaling, unique structural features, and biochemistry. However, recent advances have brought promising new drugs to clinical trials and shone a ray of hope in the field. Here, we will exposit the details of RAS biology that illustrate its key role in cell signaling and shed light on the difficulties in therapeutically targeting RAS. Furthermore, past and current efforts to develop RAS inhibitors will be discussed in depth.
Collapse
Affiliation(s)
- J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States.
| |
Collapse
|
7
|
Gašić U, Ćirić I, Pejčić T, Radenković D, Djordjević V, Radulović S, Tešić Ž. Polyphenols as Possible Agents for Pancreatic Diseases. Antioxidants (Basel) 2020; 9:antiox9060547. [PMID: 32585831 PMCID: PMC7346180 DOI: 10.3390/antiox9060547] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/26/2020] [Accepted: 05/31/2020] [Indexed: 02/06/2023] Open
Abstract
Pancreatic cancer (PC) is very aggressive and it is estimated that it kills nearly 50% of patients within the first six months. The lack of symptoms specific to this disease prevents early diagnosis and treatment. Today, gemcitabine alone or in combination with other cytostatic agents such as cisplatin (Cis), 5-fluorouracil (5-FU), irinotecan, capecitabine, or oxaliplatin (Oxa) is used in conventional therapy. Outgoing literature provides data on the use of polyphenols, biologically active compounds, in the treatment of pancreatic cancer and the prevention of acute pancreatitis. Therefore, the first part of this review gives a brief overview of the state of pancreatic disease as well as the procedures for its treatment. The second part provides a detailed overview of the research regarding the anticancer effects of both pure polyphenols and their plant extracts. The results regarding the antiproliferative, antimetastatic, as well as inhibitory effects of polyphenols against PC cell lines as well as the prevention of acute pancreatitis are presented in detail. Finally, particular emphasis is given to the polyphenolic profiles of apples, berries, cherries, sour cherries, and grapes, given the fact that these fruits are rich in polyphenols and anthocyanins. Polyphenolic profiles, the content of individual polyphenols, and their relationships are discussed. Based on this, significant data can be obtained regarding the amount of fruit that should be consumed daily to achieve a therapeutic effect.
Collapse
Affiliation(s)
- Uroš Gašić
- Department of Plant Physiology, Institute for Biological Research “Siniša Stanković”, National Institute of Republic of Serbia, University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia;
| | - Ivanka Ćirić
- Innovation Center, University of Belgrade—Faculty of Chemistry, P.O. Box 51, 11158 Belgrade, Serbia;
| | - Tomislav Pejčić
- Clinic of Urology, Clinical Centre of Serbia, Pasterova 2, 11000 Belgrade, Serbia;
| | - Dejan Radenković
- University of Belgrade—Faculty of Medicine, dr Subotića 8, 11000 Belgrade, Serbia;
- First Surgical Clinic, Clinical Center of Serbia, Koste Todorovića 6, 11000 Belgrade, Serbia;
| | - Vladimir Djordjević
- First Surgical Clinic, Clinical Center of Serbia, Koste Todorovića 6, 11000 Belgrade, Serbia;
| | - Siniša Radulović
- Institute for Oncology and Radiology of Serbia, Pasterova 14, 11000 Belgrade, Serbia;
| | - Živoslav Tešić
- University of Belgrade—Faculty of Chemistry, Studentski trg 12–16, P.O. Box 51, 11158 Belgrade, Serbia
- Correspondence: ; Tel.: +381-113336733
| |
Collapse
|
8
|
Synthesis and biological evaluation of a new series of 1-aryl-3-[4-(pyridin-2-ylmethoxy)phenyl]urea derivatives as new anticancer agents. Med Chem Res 2020; 29:1413-1423. [PMID: 32427204 PMCID: PMC7232929 DOI: 10.1007/s00044-020-02554-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 04/27/2020] [Indexed: 01/09/2023]
Abstract
The diaryl ureas are very important fragments in medicinal chemistry. By means of computer-aided design, 1-aryl-3-[4-(pyridin-2-ylmethoxy)phenyl]urea derivatives were designed and synthesized, and evaluated for their antiproliferative activity against A549, HCT-116, PC-3 cancer cell lines, and HL7702 human normal liver cell lines in vitro by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Most of the target compounds demonstrate significant antiproliferative effects on all the selective cancer cell lines. The calculated IC50 values were reported. The target compound 1-(4-chlorophenyl)-3-{4-{[3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl]methoxy}phenyl}urea (7u) demonstrated the most potent inhibitory activity (IC50 = 2.39 ± 0.10 μM for A549 and IC50 = 3.90 ± 0.33 μM for HCT-116), comparable to the positive-control sorafenib (IC50 = 2.12 ± 0.18 μM for A549 and IC50 = 2.25 ± 0.71 μM for HCT-116). Conclusively, 1-aryl-3-[4-(pyridin-2-ylmethoxy)phenyl]urea derivatives as the new anticancer agents were discovered, and could be used as the potential BRAF inhibitors for further research.
Collapse
|
9
|
Abstract
MEK, a central component of the Ras/MAPK cascade, is mutated in human tumors and developmental disorders. Recent studies are beginning to dissect the mechanisms that make these MEK mutants hyperactive.
Collapse
Affiliation(s)
- Lee Bardwell
- Department of Developmental and Cell Biology, 2208 Natural Sciences I, University of California, Irvine, CA 92697-2300, USA.
| |
Collapse
|
10
|
Prediction of sorafenib treatment–related gene expression for hepatocellular carcinoma: preoperative MRI and histopathological correlation. Eur Radiol 2018; 29:2272-2282. [DOI: 10.1007/s00330-018-5882-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/19/2018] [Accepted: 11/09/2018] [Indexed: 01/15/2023]
|
11
|
Krayem M, Najem A, Journe F, Morandini R, Sales F, Awada A, Ghanem GE. Acquired resistance to BRAFi reverses senescence-like phenotype in mutant BRAF melanoma. Oncotarget 2018; 9:31888-31903. [PMID: 30159130 PMCID: PMC6112757 DOI: 10.18632/oncotarget.25879] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 07/12/2018] [Indexed: 02/06/2023] Open
Abstract
Targeting MAPK pathway in mutant BRAF melanoma with the specific BRAF inhibitor vemurafenib showed robust initial responses in the majority of patients followed by relapses due to acquired resistance to the drug. In V600EBRAF melanoma cell lines, senescence-associated β-galactosidase activity is often encountered in a constitutive manner or induced after MAPK inhibition. However, the link between the senescence-like phenotype and the resistance to BRAF inhibition is not fully understood yet. Our data validate a senescence-like phenotype (low cell proliferation, high cell volume, and high β-Gal activity) in mutant BRAF cells. Vemurafenib increased β-Gal activity in 4 out of 5 sensitive lines and in 2 out of 5 lines with intrinsic resistance to the drug. Interestingly, the 3 lines with acquired resistance to vemurafenib became depending on the drug for proliferation. In absence of drug, these lines showed a lower cell proliferation rate together with a substantial increase of β-Gal activity both in vitro and in vivo. In all settings, the senescence-like phenotype was significantly associated with an inhibition of pRB and cyclin D1, explaining the inhibition of cell proliferation. In conclusion, β-Gal activity is increased by V600EBRAF inhibition in the majority of sensitive and intrinsically resistant melanoma cells. Acquired resistance to vemurafenib is associated with a dependence to the drug for cell proliferation and tumor growth, and, in this case, drug removal stimulate β-Gal activity suggesting that the senescence-like phenotype could contribute to the acquired resistance to BRAF inhibition.
Collapse
Affiliation(s)
- Mohammad Krayem
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Ahmad Najem
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabrice Journe
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.,Service d'Anatomie Humaine et d'Oncologie Expérimentale, Université de Mons, Mons, Belgium
| | - Renato Morandini
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - François Sales
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Ahmad Awada
- Department of Internal Medicine, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Ghanem E Ghanem
- Laboratory of Oncology and Experimental Surgery, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| |
Collapse
|
12
|
Li S, Liu J, Tan J, Li L, Kaltreider MJ, Zhao J, Kass DJ, Shang D, Zhao Y. Inhibition of Raf1 ameliorates bleomycin-induced pulmonary fibrosis through attenuation of TGF-β1 signaling. Am J Physiol Lung Cell Mol Physiol 2018; 315:L241-L247. [PMID: 29722566 DOI: 10.1152/ajplung.00093.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease associated with aberrant activation and differentiation of fibroblasts, leading to abnormal extracellular matrix production. Currently, it is still an untreatable disease (except for lung transplantation). Here, we demonstrate that the Raf1 inhibitor GW5074 ameliorates lung fibrosis in bleomycin-induced pulmonary fibrosis. Posttreatment with GW5074 reduced fibronectin (FN) expression, collagen deposition, and inflammatory cell infiltration in bleomycin-challenged mice, suggesting an antifibrotic property of GW5074. To determine the molecular mechanisms by which inhibition of Raf1 ameliorates lung fibrosis, we investigated the role of Raf1 in TGF-β1 signaling in human lung fibroblasts. GW5074 or downregulation of Raf1 by siRNAs significantly attenuated TGF-β1-induced smooth muscle actin, FN, and collagen I expression, whereas overexpression of Raf1 promoted the effects of TGF-β1 in lung fibroblasts. Furthermore, we found that Raf1-promoted TGF-β1 signaling was through the Raf1/ERK/Smad pathway and contributed to the cell proliferation and migration in human lung fibroblasts. This study provides preclinical and mechanistic evidence for development of Raf1 inhibitors as potential antifibrotic drugs for the treatment of IPF.
Collapse
Affiliation(s)
- Shuang Li
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University , Dalian, Liaoning , China.,Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Jia Liu
- Department of Thyroid Surgery, The First Hospital of Jilin University , Changchun, Jilin , China.,Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Jiangning Tan
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Lian Li
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Mary J Kaltreider
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Jing Zhao
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Daniel J Kass
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Dong Shang
- Department of General Surgery, The First Affiliated Hospital of Dalian Medical University , Dalian, Liaoning , China
| | - Yutong Zhao
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| |
Collapse
|
13
|
Abstract
The activating BRAF mutation V600E and related mutations in this codon are most important for the activation of the RAS/RAF/MEK/ERK mitogen-activated protein kinase (MAPK) signalling pathway in melanoma. BRAF V600E mutations have been detected in ~40% of melanoma patients and BRAF V600K mutations in ~5% of melanoma patients. Activation of the MAPK pathway results in continuous stimulation of cell proliferation and inhibits programmed cell death. Vemurafenib (PLX4032) was developed as a low-molecular-weight molecule for the inhibition of the mutated serine-threonine kinase BRAF, and it selectively binds to the ATP-binding site of BRAF V600E kinase and inhibits its activity. The biochemical affinity of vemurafenib for mutated BRAF translates to potent inhibition of ERK phosphorylation and of cell proliferation exclusively in BRAF-mutant cell lines. In animal model experiments, it was demonstrated that vemurafenib achieved tumour regressions in cells harbouring the BRAF V600E mutation. The clinical trials with vemurafenib in unresectable metastatic melanoma in phases I, II and III for patients harbouring BRAF V600E mutations demonstrated all unexpected high objective response rates ranging between 50 and 80%. Median progression-free survival was prolonged from 2 months with dacarbazine to 7 months with vemurafenib, and median overall survival was, respectively, prolonged from 9 to 14 months. A major problem remains in the development of resistance to vemurafenib treatment after several months in the majority of patients, and multiple resistance mechanisms have already been described. Under vemurafenib treatment, about 25% of patients developed cutaneous squamous cell carcinomas of the keratoacanthoma type with low invasive potential and without the occurrence of metastasis. The overall tolerability of the drug was quite good, and many patients remained on treatment for long times. As other solid tumours like papillary thyroid cancer, colorectal cancer, non-small-cell lung cancer and ovarian cancer likewise harbour BRAF mutation, vemurafenib is also tested in these entities. In future, combinations of vemurafenib with other kinase inhibitors and with immunotherapies will improve its therapeutic potential.
Collapse
Affiliation(s)
- Claus Garbe
- Division of Dermatooncology, Department of Dermatology, University Medical Centre, Liebermeisterstr. 25, 72074, Tuebingen, Germany.
| | - Thomas K Eigentler
- Division of Dermatooncology, Department of Dermatology, University Medical Centre, Liebermeisterstr. 25, 72074, Tuebingen, Germany
| |
Collapse
|
14
|
Mahapatra DK, Asati V, Bharti SK. MEK inhibitors in oncology: a patent review (2015-Present). Expert Opin Ther Pat 2017; 27:887-906. [DOI: 10.1080/13543776.2017.1339688] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Debarshi Kar Mahapatra
- Dadasaheb Balpande College of Pharmacy, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Vivek Asati
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, India
| | - Sanjay Kumar Bharti
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, India
| |
Collapse
|
15
|
Zhao Y, Fan D, Ru B, Cheng KW, Hu S, Zhang J, Li ETS, Wang M. 6-C-(E-phenylethenyl)naringenin induces cell growth inhibition and cytoprotective autophagy in colon cancer cells. Eur J Cancer 2016; 68:38-50. [PMID: 27710830 DOI: 10.1016/j.ejca.2016.09.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/27/2016] [Accepted: 09/01/2016] [Indexed: 12/30/2022]
Abstract
6-C-(E-phenylethenyl)naringenin (6-CEPN) is a small molecule found in naringenin fortified fried beef. It has been shown to suppress colon cancer cell proliferation, but the underlying mechanisms are not fully understood. Here we demonstrate that 6-CEPN suppresses tumour cell proliferation through cell cycle arrest in G1 phase, induces necrotic cell death and autophagy in colon cancer cells. Blockade of autophagy by knockdown of the essential autophagy proteins, Atg7 or beclin-1, resulted in aggravated cell death in response to 6-CEPN treatment. In addition, genome-wide transcriptome expression profiling by RNA-sequencing revealed that 6-CEPN-mediated gene expression pattern was extremely similar to the transcriptome response induced by a RAS inhibitor salirasib (farnesylthiosalicylic acid [FTS; salirasib]). Subsequent molecular biological and biochemical experiments demonstrated that 6-CEPN indeed strongly inhibited RAS activation, leading to the inhibition of the downstream effector pathways c-Raf/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase kinase and phosphoinositide 3-kinase/AKT/mammalian target of rapamycin. More importantly, our computational molecular docking data showed that 6-CEPN could bind to the active site of isoprenylcysteine carboxyl methyltransferase (Icmt), a critical enzyme for the activation of RAS. Icmt activity assay showed that 6-CEPN inhibited its activity significantly. Knockdown of Icmt by siRNA attenuated 6-CEPN-mediated autophagy and cell death. The present study demonstrates that 6-CEPN induces cell growth inhibition and cytoprotective autophagy in colon cancer cells, at least in part, though inhibition of the Icmt/RAS signalling pathways.
Collapse
Affiliation(s)
- Yueliang Zhao
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Daming Fan
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Beibei Ru
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Ka-Wing Cheng
- College of Engineering, Peking University, Haidian District, Beijing, China
| | - Shuting Hu
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Jiangwen Zhang
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Edmund T S Li
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Mingfu Wang
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
| |
Collapse
|
16
|
Valiathan GM, Thenumgal SJ, Jayaraman B, Palaniyandi A, Ramkumar H, Jayakumar K, Bhaskaran S, Ramanathan A. Common docking domain mutation E322K of the ERK2 gene is infrequent in oral squamous cell carcinomas. Asian Pac J Cancer Prev 2016; 13:6155-7. [PMID: 23464422 DOI: 10.7314/apjcp.2012.13.12.6155] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mutations in the MAPK (Mitogen Activated Protein Kinase) signaling pathway - EGFR/Ras/ RAF/MEK have been associated with the development of several carcinomas. ERK2, a downstream target of the MAPK pathway and a founding member of the MAPK family is activated by cellular signals emanating at the cell membrane. Activated ERK2 translocates into the nucleus to transactivate genes that promote cell proliferation. MKP - a dual specific phosphatase - interacts with activated ERK2 via the common docking (CD) domain of the later to inactivate (dephosphorylate) and effectively terminate further cell proliferation. A constitutively active form of ERK2 carrying a single point mutation (E322K) in its CD domain, was earlier reported by our laboratory. In the present study, we investigated the prevalence of this CD domain E322K mutation in 88 well differentiated OSCC tissue samples. MATERIALS AND METHOD Genomic DNA specimens isolated from 88 oral squamous cell carcinoma tissue samples were amplified with primers flanking the CD domain of the ERK2 gene. Subsequently, PCR amplicons were gel purified and subjected to direct sequencing to screen for mutations. RESULTS Direct sequencing of eighty eight OSCC samples identified an E322K CD domain mutation in only one (1.1%) OSCC sample. CONCLUSIONS Our result indicates that mutation in the CD domain of ERK2 is rare in OSCC patients, which suggests the role of genetic alterations in other mitogenic genes in the development of carcinoma in the rest of the patients. Nevertheless, the finding is clinically significant, as the relatively rare prevalence of the E322K mutation in OSCC suggests that ERK2, being a common end point signal in the multi-hierarchical mitogen activated signaling pathway may be explored as a viable drug target in the treatment of OSCC.
Collapse
|
17
|
Asati V, Mahapatra DK, Bharti SK. PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways inhibitors as anticancer agents: Structural and pharmacological perspectives. Eur J Med Chem 2016; 109:314-41. [PMID: 26807863 DOI: 10.1016/j.ejmech.2016.01.012] [Citation(s) in RCA: 396] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 12/17/2022]
Abstract
The protein kinases regulate cellular functions such as transcription, translation, proliferation, growth and survival by the process of phosphorylation. Over activation of signaling pathways play a major role in oncogenesis. The PI3K signaling pathway is dysregulated almost in all cancers due to the amplification, genetic mutation of PI3K gene and the components of the PI3K pathway themselves. Stimulation of the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK pathways enhances growth, survival, and metabolism of cancer cells. Recently, the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways have been identified as promising therapeutic targets for cancer therapy. The kinase inhibitors with enhanced specificity and improved pharmacokinetics have been considered for design and development of anticancer agents. This review focuses primarily on the Ras/Raf/MEK/ERK and PI3K/Akt/mTOR signaling pathways as therapeutic targets of anticancer drugs, their specific and dual inhibitors, structure activity relationships (SARs) and inhibitors under clinical trials.
Collapse
Affiliation(s)
- Vivek Asati
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur 495009, Chhattisgarh, India
| | - Debarshi Kar Mahapatra
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur 495009, Chhattisgarh, India
| | - Sanjay Kumar Bharti
- Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur 495009, Chhattisgarh, India.
| |
Collapse
|
18
|
Padavano J, Henkhaus RS, Chen H, Skovan BA, Cui H, Ignatenko NA. Mutant K-RAS Promotes Invasion and Metastasis in Pancreatic Cancer Through GTPase Signaling Pathways. CANCER GROWTH AND METASTASIS 2015; 8:95-113. [PMID: 26512205 PMCID: PMC4612127 DOI: 10.4137/cgm.s29407] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 12/13/2022]
Abstract
Pancreatic ductal adenocarcinoma is one of the most aggressive malignancies, characterized by the local invasion into surrounding tissues and early metastasis to distant organs. Oncogenic mutations of the K-RAS gene occur in more than 90% of human pancreatic cancers. The goal of this study was to investigate the functional significance and downstream effectors of mutant K-RAS oncogene in the pancreatic cancer invasion and metastasis. We applied the homologous recombination technique to stably disrupt K-RAS oncogene in the human pancreatic cell line MiaPaCa-2, which carries the mutant K-RAS (G12C) oncogene in both alleles. Using in vitro assays, we found that clones with disrupted mutant K-RAS gene exhibited low RAS activity, reduced growth rates, increased sensitivity to the apoptosis inducing agents, and suppressed motility and invasiveness. In vivo assays showed that clones with decreased RAS activity had reduced tumor formation ability in mouse xenograft model and increased survival rates in the mouse orthotopic pancreatic cancer model. We further examined molecular pathways downstream of mutant K-RAS and identified RhoA GTP activating protein 5, caveolin-1, and RAS-like small GTPase A (RalA) as key effector molecules, which control mutant K-RAS-dependent migration and invasion in MiaPaCa-2 cells. Our study provides rational for targeting RhoA and RalA GTPase signaling pathways for inhibition of pancreatic cancer metastasis.
Collapse
Affiliation(s)
- Julianna Padavano
- Department of Biochemistry and Molecular Biophysics, Undergraduate Biology Research Program, University of Arizona, Tucson, Arizona, USA
| | - Rebecca S Henkhaus
- Cancer Biology Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ, USA
| | - Hwudaurw Chen
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | - Bethany A Skovan
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | - Haiyan Cui
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | - Natalia A Ignatenko
- Department of Cellular & Molecular Medicine, University of Arizona, Tucson, AZ, USA
| |
Collapse
|
19
|
KIT and BRAF heterogeneous mutations in gastrointestinal stromal tumors after secondary imatinib resistance. Gastric Cancer 2015; 18:796-802. [PMID: 25182956 DOI: 10.1007/s10120-014-0414-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 07/28/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the digestive tract and characterized by expression of KIT protein. Imatinib is the frontline therapy for metastatic and unresectable GIST patients showing clinical responses in 80 % of cases. Despite the often long-lasting clinical benefit seen in most patients treated with imatinib, many will eventually suffer disease progression. The most frequent mechanism of imatinib resistance in GIST is the acquisition of secondary mutations in either KIT or PDGFRA. There are also some imatinib-resistant GIST patients lacking an identifiable mechanism of treatment failure. Recently, activating BRAF mutation was detected in a small percentage of GISTs. In this study, we report a case of GIST with acquired resistance to imatinib during therapy. METHODS Histological, immunohistochemical, Western blot and mutational analyses were performed on GIST tissues before and after imatinib resistance. RESULTS The imatinib-resistant tumor showed not only heterogeneous mutations of KIT and BRAF besides the primary mutation, but also transdifferentiation into a rhabdomyosarcoma phenotype. According to Western blot analysis, in imatinib-resistant GIST with both KIT V559D and BRAF V600E mutations, the inhibition of KIT V559D by imatinib caused a strong decrease of AKT phosphorylation, while ERK1/2 phosphorylation was not affected. CONCLUSIONS This finding, in combination with the loss of KIT expression, suggests the possibility of activation of RAS-RAF-MEK-ERK pathways driven by a KIT-independent oncogenic mechanism. Understanding the genetic aberrations beyond KIT and PDGFRA may lead to the identification of additional therapeutic targets for GISTs.
Collapse
|
20
|
de Iriarte Rodríguez R, Magariños M, Pfeiffer V, Rapp UR, Varela-Nieto I. C-Raf deficiency leads to hearing loss and increased noise susceptibility. Cell Mol Life Sci 2015; 72:3983-98. [PMID: 25975225 PMCID: PMC4575698 DOI: 10.1007/s00018-015-1919-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 12/20/2022]
Abstract
The family of RAF kinases transduces extracellular information to the nucleus, and their activation is crucial for cellular regulation on many levels, ranging from embryonic development to carcinogenesis. B-RAF and C-RAF modulate neurogenesis and neuritogenesis during chicken inner ear development. C-RAF deficiency in humans is associated with deafness in the rare genetic insulin-like growth factor 1 (IGF-1), Noonan and Leopard syndromes. In this study, we show that RAF kinases are expressed in the developing inner ear and in adult mouse cochlea. A homozygous C-Raf deletion in mice caused profound deafness with no evident cellular aberrations except for a remarkable reduction of the K+ channel Kir4.1 expression, a trait that suffices as a cause of deafness. To explore the role of C-Raf in cellular protection and repair, heterozygous C-Raf+/− mice were exposed to noise. A reduced C-RAF level negatively affected hearing preservation in response to noise through mechanisms involving the activation of JNK and an exacerbated apoptotic response. Taken together, these results strongly support a role for C-RAF in hearing protection.
Collapse
Affiliation(s)
- Rocío de Iriarte Rodríguez
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain.,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain
| | - Marta Magariños
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain. .,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain. .,Departamento de Biología, Universidad Autónoma de Madrid, Darwin 2, 28049, Madrid, Spain.
| | - Verena Pfeiffer
- Institute for Medical Radiation and Cell Research (MSZ), University of Würzburg, Versbacher Strasse 5, 97078, Würzburg, Germany.,Institute for Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070, Würzburg, Germany
| | - Ulf R Rapp
- Institute for Medical Radiation and Cell Research (MSZ), University of Würzburg, Versbacher Strasse 5, 97078, Würzburg, Germany.,Molecular Mechanisms of Lung Cancer, Max Planck Institute for Heart and Lung Research, Parkstr. 1, 61231, Bad Nauheim, Germany
| | - Isabel Varela-Nieto
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain.,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| |
Collapse
|
21
|
Epidermal growth factor-induced prostate cancer (PC3) cell survival and proliferation is inhibited by quercetin, a plant flavonoid through apoptotic machinery. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.bionut.2014.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
22
|
Tie J, Desai J. Targeting BRAF mutant metastatic colorectal cancer: clinical implications and emerging therapeutic strategies. Target Oncol 2014; 10:179-88. [PMID: 25119972 DOI: 10.1007/s11523-014-0330-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 07/24/2014] [Indexed: 12/16/2022]
Abstract
Increasing knowledge of the underlying signaling pathways and molecular defects involved in colorectal cancer growth or progression enabled the discovery of several prognostic and predictive biomarkers, leading to the development of novel molecularly targeted therapies. The mitogen-activated protein kinase (MAPK) signaling pathway plays a critical role in colorectal cancer progression. Mutations in BRAF, a principal effector of Ras in this signaling cascade, are found in 10 % of colorectal cancer and play a clear pathogenic role, particularly in patients with metastatic disease. Intense efforts have therefore focused on targeting BRAF as an oncogenic driver, with mixed early results. This article summarizes the molecular and clinical features of BRAF mutant colorectal cancer, the prognostic and predictive role of BRAFV600E mutation in colorectal cancer, initial clinical trial results in targeting BRAFV600E, and the more recent preclinical insights into potential mechanisms of resistance to BRAF inhibition that have now led to a number of rationale-driven combination therapeutic strategies.
Collapse
Affiliation(s)
- Jeanne Tie
- Ludwig Colon Cancer Initiative Laboratory, Ludwig Institute for Cancer Research, Parkville, VIC, Australia
| | | |
Collapse
|
23
|
Mooz J, Oberoi-Khanuja TK, Harms GS, Wang W, Jaiswal BS, Seshagiri S, Tikkanen R, Rajalingam K. Dimerization of the kinase ARAF promotes MAPK pathway activation and cell migration. Sci Signal 2014; 7:ra73. [PMID: 25097033 DOI: 10.1126/scisignal.2005484] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The RAF family of kinases mediates RAS signaling, and RAF inhibitors can be effective for treating tumors with BRAF(V600E) mutant protein. However, RAF inhibitors paradoxically accelerate metastasis in RAS-mutant tumors and become ineffective in BRAF(V600E) tumors because of reactivation of downstream mitogen-activated protein kinase (MAPK) signaling. We found that the RAF isoform ARAF has an obligatory role in promoting MAPK activity and cell migration in a cell type-dependent manner. Knocking down ARAF prevented the activation of MAPK kinase 1 (MEK1) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) and decreased the number of protrusions from tumor cell spheroids in three-dimensional culture that were induced by BRAF(V600E)-specific or BRAF/CRAF inhibitors (GDC-0879 and sorafenib, respectively). RAF inhibitors induced the homodimerization of ARAF and the heterodimerization of BRAF with CRAF and the scaffolding protein KSR1. In a purified protein solution, recombinant proteins of the three RAF isoforms competed for binding to MEK1. In cells in culture, overexpressing mutants of ARAF that could not homodimerize impaired the interaction between ARAF and endogenous MEK1 and thus prevented the subsequent activation of MEK1 and ERK1/2. Our findings reveal a new role for ARAF in directly activating the MAPK cascade and promoting tumor cell invasion and suggest a new therapeutic target for RAS- and RAF-mediated cancers.
Collapse
Affiliation(s)
- Juliane Mooz
- Cell death signalling group, Institute of Biochemistry II, Goethe University Medical School, Frankfurt 60590, Germany. Institute for Immunology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, Building 708, Mainz 55131, Germany
| | - Tripat Kaur Oberoi-Khanuja
- Cell death signalling group, Institute of Biochemistry II, Goethe University Medical School, Frankfurt 60590, Germany
| | - Gregory S Harms
- Stark Learning Center, Department of Biology and Health Sciences, Wilkes University, Wilkes-Barre, Pennsylvania, PA 18766, USA
| | - Weiru Wang
- Department of Protein Engineering, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Bijay S Jaiswal
- Department of Molecular Biology, Genentech Inc., South San Francisco, CA 94080, USA
| | - Somasekar Seshagiri
- Department of Molecular Biology, Genentech Inc., South San Francisco, CA 94080, USA
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Giessen 35392, Germany
| | - Krishnaraj Rajalingam
- Cell death signalling group, Institute of Biochemistry II, Goethe University Medical School, Frankfurt 60590, Germany. Institute for Immunology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, Building 708, Mainz 55131, Germany.
| |
Collapse
|
24
|
|
25
|
Abstract
The activating BRAF mutation V600E and related mutations in this codon are most important for the activation of the RAS/RAF/MEK/ERK mitogen-activated protein kinase (MAPK) signalling pathway in melanoma. BRAF V600E mutations have been detected in ~40% of melanoma patients and BRAF V600K mutations in ~5% of melanoma patients. Activation of the MAPK pathway results in continuous stimulation of cell proliferation and inhibits programmed cell death. Vemurafenib (PLX4032) was developed as a low molecular weight molecule for the inhibition of the mutated serine threonine kinase BRAF, and it selectively binds to the ATP-binding site of BRAF-V600E kinase and inhibits its activity. The biochemical affinity of vemurafenib for mutated BRAF translates to potent inhibition of ERK phosphorylation and of cell proliferation exclusively in BRAF-mutant cell lines. In animal model experiments, it was demonstrated that vemurafenib achieved tumour regressions in cells harbouring the BRAF V600E mutation. The clinical trials with vemurafenib in unresectable metastatic melanoma in phase I, II, and III for patients harbouring BRAF V600E mutations demonstrated all unexpected high objective response rates ranging between 50 and 80%. Median progression-free survival was prolonged from two months with dacarbazine to seven months with vemurafenib, and median overall survival was respectively prolonged from 9 to 14 months. A major problem that remains is the development of resistance to vemurafenib treatment after several months in the majority of patients, and multiple resistance mechanisms have already been described. Under vemurafenib treatment, about 25% of patients developed cutaneous squamous cell carcinomas of the keratoacanthoma type with low invasive potential and without occurrence of metastasis. The overall tolerability of the drug was quite good, and a number of patients remained on treatment for long times. As other solid tumours like papillary thyroid cancer, colorectal cancer, non-small-cell lung cancer, and ovarian cancer likewise harbour BRAF mutation, vemurafenib is also tested in these entities. In future, combinations of vemurafenib with other kinase inhibitors and with immunotherapies will improve its therapeutic potential.
Collapse
|
26
|
Abstract
Noonan syndrome is a genetic multisystem disorder characterised by distinctive facial features, developmental delay, learning difficulties, short stature, congenital heart disease, renal anomalies, lymphatic malformations, and bleeding difficulties. Mutations that cause Noonan syndrome alter genes encoding proteins with roles in the RAS-MAPK pathway, leading to pathway dysregulation. Management guidelines have been developed. Several clinically relevant genotype-phenotype correlations aid risk assessment and patient management. Increased understanding of the pathophysiology of the disease could help development of pharmacogenetic treatments.
Collapse
Affiliation(s)
- Amy E Roberts
- Department of Cardiology and Division of Genetics, Children's Hospital Boston, Boston, MA 02115, USA.
| | | | | | | |
Collapse
|
27
|
Ishizuka S, Shiwaku M, Hagio M, Suzuki T, Hira T, Hara H. Glycochenodeoxycholic acid promotes proliferation of intestinal epithelia via reduction of cyclic AMP and increase in H2AX phosphorylation after exposure to γ-rays. Biomed Res 2012; 33:159-65. [PMID: 22790215 DOI: 10.2220/biomedres.33.159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Bile acids (BAs) are considered to be promotive factors in colorectal carcinogenesis. We investigated whether BAs in the cellular environment influence proliferation of intestinal epithelial cell lines. Some BAs induced proliferation in several epithelial cell lines. In the proliferation assay, significant increases in IEC-6 cell proliferation were observed in response to glycodeoxycholic acid or glycochenodeoxycholic acid (GCDCA). Among the glycine-conjugated derivatives of BAs, especially GCDCA reduced cAMP production in IEC-6 cells. Pertussis toxin completely inhibited the GCDCA-induced increase in IEC-6 proliferation, suggesting GCDCA-induced proliferation required Gαi activation and cAMP reduction. Treatment with 3-isobutyl-1-methylxanthine, a phosphodiesterase inhibitor, also suppressed GCDCA-induced IEC-6 proliferation. We confirmed an increase in MEK1/2 phosphorylation in GCDCA-treated IEC-6 cells, and inhibition of MEK1/2 by U0126 clearly suppressed GCDCA-induced IEC-6 cell proliferation. A significant increase was observed in the phosphorylation of histone H2AX in GCDCA-treated IEC-6 cells after exposure to γ-rays. Cell cycle analysis revealed that GCDCA increased the proportion of cells in S phase only after γ-ray exposure. These results indicate that glycine-conjugated BAs in the cellular environment are potent inducers of cell proliferation accompanied by genomic instability in intestinal epithelia.
Collapse
Affiliation(s)
- Satoshi Ishizuka
- Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
| | | | | | | | | | | |
Collapse
|
28
|
Himmelsbach K, Hildt E. The kinase inhibitor Sorafenib impairs the antiviral effect of interferon α on hepatitis C virus replication. Eur J Cell Biol 2012; 92:12-20. [PMID: 23107224 DOI: 10.1016/j.ejcb.2012.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 09/08/2012] [Accepted: 09/14/2012] [Indexed: 02/07/2023] Open
Abstract
Recently, it was shown that the kinase inhibitor Sorafenib efficiently blocks HCV replication by inhibition of c-Raf. However, a longer treatment with higher doses of Sorafenib might be associated with adverse effects. Therefore, it was analysed whether a decreased dose of Sorafenib can be applied in combination with interferon α to obtain additive antiviral, but at the same time decreased adverse effects. However, Sorafenib abolishes the inhibitory effect of interferon α on HCV replication and vice versa. In order to reveal the underlying mechanisms, we observed that on the one hand IFNα activates c-Raf and thereby counteracts the inhibitory effect of Sorafenib on HCV replication that is based on the Sorafenib-dependent inhibition of c-Raf. On the other hand we found that the IFNα-induced PKR-phosphorylation depends on c-Raf. So, Sorafenib as a potent inhibitor of c-Raf prevents the IFNα-dependent PKR phosphorylation. Moreover, Sorafenib inhibits c-Raf-independent the phosphorylation of STAT1 resulting in an impaired induction of IFNα-dependent genes. Taken together, these data indicate that a combined application of Sorafenib and interferon α in order to obtain an antiviral effect is not useful since Sorafenib exerts an inhibitory effect on targets that are crucial for the transduction of interferon α-dependent antiviral response.
Collapse
|
29
|
Magariños M, Contreras J, Aburto MR, Varela-Nieto I. Early development of the vertebrate inner ear. Anat Rec (Hoboken) 2012; 295:1775-90. [PMID: 23044927 DOI: 10.1002/ar.22575] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 12/12/2022]
Abstract
This is a review of the biological processes and the main signaling pathways required to generate the different otic cell types, with particular emphasis on the actions of insulin-like growth factor I. The sensory organs responsible of hearing and balance have a common embryonic origin in the otic placode. Lineages of neural, sensory, and support cells are generated from common otic neuroepithelial progenitors. The sequential generation of the cell types that will form the adult inner ear requires the coordination of cell proliferation with cell differentiation programs, the strict regulation of cell survival, and the metabolic homeostasis of otic precursors. A network of intracellular signals operates to coordinate the transcriptional response to the extracellular input. Understanding the molecular clues that direct otic development is fundamental for the design of novel treatments for the protection and repair of hearing loss and balance disorders.
Collapse
Affiliation(s)
- Marta Magariños
- Instituto de Investigaciones Biomédicas, Alberto Sols, CSIC-UAM, Madrid, Spain
| | | | | | | |
Collapse
|
30
|
Choo EF, Ng CM, Berry L, Belvin M, Lewin-Koh N, Merchant M, Salphati L. PK-PD modeling of combination efficacy effect from administration of the MEK inhibitor GDC-0973 and PI3K inhibitor GDC-0941 in A2058 xenografts. Cancer Chemother Pharmacol 2012; 71:133-43. [PMID: 23053270 DOI: 10.1007/s00280-012-1988-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 09/18/2012] [Indexed: 02/01/2023]
Abstract
PURPOSE Mutations and activations of the MEK and PI3K pathways are associated with the development of many cancers. GDC-0973 and GDC-0941 are inhibitors of MEK and PI3K, respectively, currently being evaluated clinically in combination as anti-cancer treatment. The objective of these studies was to characterize the relationship between the plasma concentrations of GDC-0973 and GDC-0941 administered in combination and efficacy in A2058 melanoma xenograft. METHODS GDC-0973 and GDC-0941 were administered to A2058 tumor-bearing mice daily (QD) or every third day (Q3D) either as single agents or in combination. A semi-mechanistic population anti-cancer model was developed to simultaneously describe the tumor growth following QD/Q3D single-agent and QD combination treatments. The interaction terms ψ included in the model were used to assess whether the combination was additive. Using this model, data from the Q3D combination regimen were simulated and compared with the observed tumor volumes. RESULTS The model consisting of saturable tumor growth provided the best fit of the data. The estimates for ψ were not significantly different from 1, suggesting an additive effect of GDC-0973 and GDC-0941 on tumor growth inhibition. The population rate constants associated with tumor growth inhibition for GDC-0973 and GDC-0941 were 0.00102 and 0000651 μM(-1) h(-1), respectively. Using the model based on single-agent and QD combination efficacy data, simulations adequately described the tumor growth from the Q3D combination regimen. CONCLUSIONS These findings suggest that, based on minimal data, it is possible to predict the effects of various combinations preclinically and also assess the potential clinical efficacy of combinations using human pharmacokinetic inputs.
Collapse
Affiliation(s)
- Edna F Choo
- Drug Metabolism and Pharmacokinetics, Genentech, Inc., South San Francisco, CA 94080, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Combining pharmacophore, docking and substructure search approaches to identify and optimize novel B-RafV600E inhibitors. Bioorg Med Chem Lett 2012; 22:5428-37. [DOI: 10.1016/j.bmcl.2012.07.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 11/18/2022]
|
32
|
Dynamic Contrast-Enhanced Computed Tomography Imaging Biomarkers Correlated With Immunohistochemistry for Monitoring the Effects of Sorafenib on Experimental Prostate Carcinomas. Invest Radiol 2012; 47:49-57. [DOI: 10.1097/rli.0b013e3182300fe4] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
33
|
Selvy PE, Lavieri RR, Lindsley CW, Brown HA. Phospholipase D: enzymology, functionality, and chemical modulation. Chem Rev 2011; 111:6064-119. [PMID: 21936578 PMCID: PMC3233269 DOI: 10.1021/cr200296t] [Citation(s) in RCA: 269] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Paige E Selvy
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37064, USA
| | | | | | | |
Collapse
|
34
|
Choo EF, Alicke B, Boggs J, Dinkel V, Gould S, Grina J, West K, Menghrajani K, Ran Y, Rudolph J, Wenglowsky S. Preclinical assessment of novel BRAF inhibitors: integrating pharmacokinetic-pharmacodynamic modelling in the drug discovery process. Xenobiotica 2011; 41:1076-87. [DOI: 10.3109/00498254.2011.603384] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
35
|
Kaoud TS, Devkota AK, Harris R, Rana MS, Abramczyk O, Warthaka M, Lee S, Girvin ME, Riggs AF, Dalby KN. Activated ERK2 is a monomer in vitro with or without divalent cations and when complexed to the cytoplasmic scaffold PEA-15. Biochemistry 2011; 50:4568-78. [PMID: 21506533 DOI: 10.1021/bi200202y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The extracellular signal-regulated protein kinase, ERK2, fully activated by phosphorylation and without a His(6) tag, shows little tendency to dimerize with or without either calcium or magnesium ions when analyzed by light scattering or analytical ultracentrifugation. Light scattering shows that ~90% of ERK2 is monomeric. Sedimentation equilibrium data (obtained at 4.8-11.2 μM ERK2) with or without magnesium (10 mM) are well described by an ideal one-component model with a fitted molar mass of 40180 ± 240 Da (without Mg(2+) ions) or 41290 ± 330 Da (with Mg(2+) ions). These values, close to the sequence-derived mass of 41711 Da, indicate that no significant dimerization of ERK2 occurs in solution. Analysis of sedimentation velocity data for a 15 μM solution of ERK2 with an enhanced van Holde-Weischet method determined the sedimentation coefficient (s) to be ~3.22 S for activated ERK2 with or without 10 mM MgCl(2). The frictional coefficient ratio (f/f(0)) of 1.28 calculated from the sedimentation velocity and equilibrium data is close to that expected for an ~42 kDa globular protein. The translational diffusion coefficient of ~8.3 × 10(-7) cm(2) s(-1) calculated from the experimentally determined molar mass and sedimentation coefficient agrees with the value determined by dynamic light scattering in the absence and presence of calcium or magnesium ions and a value determined by NMR spectrometry. ERK2 has been proposed to homodimerize and bind only to cytoplasmic but not nuclear proteins [Casar, B., et al. (2008) Mol. Cell 31, 708-721]. Our light scattering data show, however, that ERK2 forms a strong 1:1 complex of ~57 kDa with the cytoplasmic scaffold protein PEA-15. Thus, ERK2 binds PEA-15 as a monomer. Our data provide strong evidence that ERK2 is monomeric under physiological conditions. Analysis of the same ERK2 construct with the nonphysiological His(6) tag shows substantial dimerization under the same ionic conditions.
Collapse
Affiliation(s)
- Tamer S Kaoud
- Division of Medicinal Chemistry, University of Texas, Austin, TX 78712, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Baljuls A, Mahr R, Schwarzenau I, Müller T, Polzien L, Hekman M, Rapp UR. Single substitution within the RKTR motif impairs kinase activity but promotes dimerization of RAF kinase. J Biol Chem 2011; 286:16491-503. [PMID: 21454547 DOI: 10.1074/jbc.m110.194167] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The serine/threonine kinase RAF is a central component of the MAPK cascade. Regulation of RAF activity is highly complex and involves recruitment to membranes and association with Ras and scaffold proteins as well as multiple phosphorylation and dephosphorylation events. Previously, we identified by molecular modeling an interaction between the N-region and the RKTR motif of the kinase domain in RAF and assigned a new function to this tetrapeptide segment. Here we found that a single substitution of each basic residue within the RKTR motif inhibited catalytic activity of all three RAF isoforms. However, the inhibition and phosphorylation pattern of C-RAF and A-RAF differed from B-RAF. Furthermore, substitution of the first arginine led to hyperphosphorylation and accumulation of A-RAF and C-RAF in plasma membrane fraction, indicating that this residue interferes with the recycling process of A-RAF and C-RAF but not B-RAF. In contrast, all RAF isoforms behave similarly with respect to the RKTR motif-dependent dimerization. The exchange of the second arginine led to exceedingly increased dimerization as long as one of the protomers was not mutated, suggesting that substitution of this residue with alanine may result in similar a structural rearrangement of the RAF kinase domain, as has been found for the C-RAF kinase domain co-crystallized with a dimerization-stabilizing RAF inhibitor. In summary, we provide evidence that each of the basic residues within the RKTR motif is indispensable for correct RAF function.
Collapse
Affiliation(s)
- Angela Baljuls
- Theodor-Boveri Institute of Bioscience, Department of Microbiology, University of Wuerzburg, Wuerzburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
37
|
Neel NF, Martin TD, Stratford JK, Zand TP, Reiner DJ, Der CJ. The RalGEF-Ral Effector Signaling Network: The Road Less Traveled for Anti-Ras Drug Discovery. Genes Cancer 2011; 2:275-87. [PMID: 21779498 PMCID: PMC3128631 DOI: 10.1177/1947601911407329] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The high frequency of RAS mutations in human cancers (33%) has stimulated intense interest in the development of anti-Ras inhibitors for cancer therapy. Currently, the major focus of these efforts is centered on inhibitors of components involved in Ras downstream effector signaling. In particular, more than 40 inhibitors of the Raf-MEK-ERK mitogen-activated protein kinase cascade and phosphoinositide 3-kinase-AKT-mTOR effector signaling networks are currently under clinical evaluation. However, these efforts are complicated by the fact that Ras can utilize at least 9 additional functionally distinct effectors, with at least 3 additional effectors with validated roles in Ras-mediated oncogenesis. Of these, the guanine nucleotide exchange factors of the Ras-like (Ral) small GTPases (RalGEFs) have emerged as important effectors of mutant Ras in pancreatic, colon, and other cancers. In this review, we summarize the evidence for the importance of this effector pathway in cancer and discuss possible directions for therapeutic inhibition of aberrant Ral activation and signaling.
Collapse
Affiliation(s)
- Nicole F Neel
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | | | | | | | | |
Collapse
|
38
|
Polzien L, Baljuls A, Albrecht M, Hekman M, Rapp UR. BAD contributes to RAF-mediated proliferation and cooperates with B-RAF-V600E in cancer signaling. J Biol Chem 2011; 286:17934-44. [PMID: 21317286 DOI: 10.1074/jbc.m110.177345] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BAD (Bcl-2 antagonist of cell death) belongs to the proapoptotic BH3-only subfamily of Bcl-2 proteins. Physiological activity of BAD is highly controlled by phosphorylation. To further analyze the regulation of BAD function, we investigated the role of recently identified phosphorylation sites on BAD-mediated apoptosis. We found that in contrast to the N-terminal phosphorylation sites, the serines 124 and 134 act in an antiapoptotic manner because the replacement by alanine led to enhanced cell death. Our results further indicate that RAF kinases represent, besides PAK1, BAD serine 134 phosphorylating kinases. Importantly, in the presence of wild type BAD, co-expression of survival kinases, such as RAF and PAK1, leads to a strongly increased proliferation, whereas substitution of serine 134 by alanine abolishes this process. Furthermore, we identified BAD serine 134 to be strongly involved in survival signaling of B-RAF-V600E-containing tumor cells and found that phosphorylation of BAD at this residue is critical for efficient proliferation in these cells. Collectively, our findings provide new insights into the regulation of BAD function by phosphorylation and its role in cancer signaling.
Collapse
Affiliation(s)
- Lisa Polzien
- Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
| | | | | | | | | |
Collapse
|
39
|
Tian Y, Hu Y, Wang Z, Chen K, Zhang L, Wang L, Ren M, Huang A, Tang H. Hepatitis B virus regulates Raf1 expression in HepG2.2.15 cells by enhancing its promoter activity. Arch Virol 2011; 156:869-74. [DOI: 10.1007/s00705-010-0901-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 12/20/2010] [Indexed: 11/29/2022]
|
40
|
Magariños M, Aburto MR, Sánchez-Calderón H, Muñoz-Agudo C, Rapp UR, Varela-Nieto I. RAF kinase activity regulates neuroepithelial cell proliferation and neuronal progenitor cell differentiation during early inner ear development. PLoS One 2010; 5:e14435. [PMID: 21203386 PMCID: PMC3010996 DOI: 10.1371/journal.pone.0014435] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Accepted: 11/24/2010] [Indexed: 12/21/2022] Open
Abstract
Background Early inner ear development requires the strict regulation of cell proliferation, survival, migration and differentiation, coordinated by the concerted action of extrinsic and intrinsic factors. Deregulation of these processes is associated with embryonic malformations and deafness. We have shown that insulin-like growth factor I (IGF-I) plays a key role in embryonic and postnatal otic development by triggering the activation of intracellular lipid and protein kinases. RAF kinases are serine/threonine kinases that regulate the highly conserved RAS-RAF-MEK-ERK signaling cascade involved in transducing the signals from extracellular growth factors to the nucleus. However, the regulation of RAF kinase activity by growth factors during development is complex and still not fully understood. Methodology/Principal Findings By using a combination of qRT-PCR, Western blotting, immunohistochemistry and in situ hybridization, we show that C-RAF and B-RAF are expressed during the early development of the chicken inner ear in specific spatiotemporal patterns. Moreover, later in development B-RAF expression is associated to hair cells in the sensory patches. Experiments in ex vivo cultures of otic vesicle explants demonstrate that the influence of IGF-I on proliferation but not survival depends on RAF kinase activating the MEK-ERK phosphorylation cascade. With the specific RAF inhibitor Sorafenib, we show that blocking RAF activity in organotypic cultures increases apoptosis and diminishes the rate of cell proliferation in the otic epithelia, as well as severely impairing neurogenesis of the acoustic-vestibular ganglion (AVG) and neuron maturation. Conclusions/Significance We conclude that RAF kinase activity is essential to establish the balance between cell proliferation and death in neuroepithelial otic precursors, and for otic neuron differentiation and axonal growth at the AVG.
Collapse
Affiliation(s)
- Marta Magariños
- Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM, Madrid, Spain.
| | | | | | | | | | | |
Collapse
|
41
|
Tartaglia M, Gelb BD. Disorders of dysregulated signal traffic through the RAS-MAPK pathway: phenotypic spectrum and molecular mechanisms. Ann N Y Acad Sci 2010; 1214:99-121. [PMID: 20958325 PMCID: PMC3010252 DOI: 10.1111/j.1749-6632.2010.05790.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
RAS GTPases control a major signaling network implicated in several cellular functions, including cell fate determination, proliferation, survival, differentiation, migration, and senescence. Within this network, signal flow through the RAF-MEK-ERK pathway-the first identified mitogen-associated protein kinase (MAPK) cascade-mediates early and late developmental processes controlling morphology determination, organogenesis, synaptic plasticity, and growth. Signaling through the RAS-MAPK cascade is tightly controlled; and its enhanced activation represents a well-known event in oncogenesis. Unexpectedly, in the past few years, inherited dysregulation of this pathway has been recognized as the cause underlying a group of clinically related disorders sharing facial dysmorphism, cardiac defects, reduced postnatal growth, ectodermal anomalies, variable cognitive deficits, and susceptibility to certain malignancies as major features. These disorders are caused by heterozygosity for mutations in genes encoding RAS proteins, regulators of RAS function, modulators of RAS interaction with effectors, or downstream signal transducers. Here, we provide an overview of the phenotypic spectrum associated with germline mutations perturbing RAS-MAPK signaling, the unpredicted molecular mechanisms converging toward the dysregulation of this signaling cascade, and major genotype-phenotype correlations.
Collapse
Affiliation(s)
- Marco Tartaglia
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome, Italy.
| | | |
Collapse
|
42
|
Martin C, Chen S, Heilos D, Sauer G, Hunt J, Shaw AG, Sims PFG, Jackson DA, Lovrić J. Changed genome heterochromatinization upon prolonged activation of the Raf/ERK signaling pathway. PLoS One 2010; 5:e13322. [PMID: 20967285 PMCID: PMC2953519 DOI: 10.1371/journal.pone.0013322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 09/10/2010] [Indexed: 11/18/2022] Open
Abstract
The Raf/ERK (Extracellular Signal Regulated Kinase) signal transduction pathway controls numerous cellular processes, including growth, differentiation, cellular transformation and senescence. ERK activation is thought to involve complex spatial and temporal regulation, to achieve a high degree of specificity, though precisely how this is achieved remains to be confirmed. We report here that prolonged activation of a conditional form of c-Raf-1 (BXB-ER) leads to profound changes in the level and distribution of a heterochromatic histone mark. In mouse fibroblasts, the heterochromatic trimethylation of lysine 9 in histone H3 (H3K9Me3) is normally confined to pericentromeric regions. However, following ERK activation a genome-wide redistribution of H3K9Me3 correlates with loss of the histone modification from chromocentres and the appearance of numerous punctuate sites throughout the interphase nucleus. These epigenetic changes during interphase correlate with altered chromosome structure during mitosis, where robust H3K9Me3 signals appear within telomeric heterochromatin. This pattern of heterochromatinization is distinct from previously described oncogene induced senescence associated heterochromatin foci (SAHF), which are excluded from telomeres. The H3K9Me3 histone mark is known to bind the major heterochromatin protein HP1 and we show that the alterations in the distribution of this histone epistate correlate with redistribution of HP1β throughout the nucleus. Interestingly while ERK activation is fully reversible, the observed chromatin changes induced by epigenetic modifications are not reversible once established. We describe for the first time a link from prolonged ERK activation to stable changes in genome organization through redistribution of heterochromatic domains involving the telomeres. These epigenetic changes provide a possible mechanism through which prolonged activation of Raf/ERK can lead to growth arrest or the induction of differentiation, senescence and cancer.
Collapse
Affiliation(s)
- Catherine Martin
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| | - Songbi Chen
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
| | - Daniela Heilos
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| | - Guido Sauer
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Jessica Hunt
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| | - Alexander George Shaw
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| | - Paul Francis George Sims
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| | - Dean Andrew Jackson
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| | - Josip Lovrić
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
| |
Collapse
|
43
|
Hu B, He X, Li A, Qiu Q, Li C, Liang D, Zhao P, Ma J, Coffey RJ, Zhan Q, Wu G. Cystogenesis in ARPKD results from increased apoptosis in collecting duct epithelial cells of Pkhd1 mutant kidneys. Exp Cell Res 2010; 317:173-87. [PMID: 20875407 DOI: 10.1016/j.yexcr.2010.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 09/09/2010] [Accepted: 09/19/2010] [Indexed: 12/14/2022]
Abstract
Mutations in the PKHD1 gene result in autosomal recessive polycystic kidney disease (ARPKD) in humans. To determine the molecular mechanism of the cystogenesis in ARPKD, we recently generated a mouse model for ARPKD that carries a targeted mutation in the mouse orthologue of human PKHD1. The homozygous mutant mice display hepatorenal cysts whose phenotypes are similar to those of human ARPKD patients. By littermates of this mouse, we developed two immortalized renal collecting duct cell lines with Pkhd1 and two without. Under nonpermissive culture conditions, the Pkhd1(-/-) renal cells displayed aberrant cell-cell contacts and tubulomorphogenesis. The Pkhd1(-/-) cells also showed significantly reduced cell proliferation and elevated apoptosis. To validate this finding in vivo, we examined proliferation and apoptosis in the kidneys of Pkhd1(-/-) mice and their wildtype littermates. Using proliferation (PCNA and Histone-3) and apoptosis (TUNEL and caspase-3) markers, similar results were obtained in the Pkhd1(-/-) kidney tissues as in the cells. To identify the molecular basis of these findings, we analyzed the effect of Pkhd1 loss on multiple putative signaling regulators. We demonstrated that the loss of Pkhd1 disrupts multiple major phosphorylations of focal adhesion kinase (FAK), and these disruptions either inhibit the Ras/C-Raf pathways to suppress MEK/ERK activity and ultimately reduce cell proliferation, or suppress PDK1/AKT to upregulate Bax/caspase-9/caspase-3 and promote apoptosis. Our findings indicate that apoptosis may be a major player in the cyst formation in ARPKD, which may lead to new therapeutic strategies for human ARPKD.
Collapse
MESH Headings
- Animals
- Apoptosis/genetics
- Caspase 3/genetics
- Caspase 3/metabolism
- Caspase 9/genetics
- Caspase 9/metabolism
- Cell Line, Transformed
- Cell Proliferation
- Crosses, Genetic
- Cysts/genetics
- Disease Models, Animal
- Epithelial Cells/metabolism
- Genes, cdc
- Genotype
- Humans
- In Vitro Techniques
- Kidney/metabolism
- Kidney Tubules, Collecting/metabolism
- Mice
- Mice, Congenic
- Mice, Inbred C57BL
- Mice, Knockout
- Mutation
- Phenotype
- Polycystic Kidney, Autosomal Recessive/genetics
- Polycystic Kidney, Autosomal Recessive/metabolism
- Polycystic Kidney, Autosomal Recessive/pathology
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Receptors, Cell Surface/genetics
- Signal Transduction/genetics
Collapse
Affiliation(s)
- Bo Hu
- Cancer Research Institute, University of South China, Hengyang, Hunan, 421001, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Waldner MJ, Neurath MF. The molecular therapy of colorectal cancer. Mol Aspects Med 2010; 31:171-8. [PMID: 20171980 DOI: 10.1016/j.mam.2010.02.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 02/16/2010] [Indexed: 12/14/2022]
Abstract
Although colorectal cancer (CRC) is still one of the leading causes of cancer related death in the western hemisphere, new therapeutic options have increased the overall survival rate of advanced disease from 10 to 18-24months during the past decade. The new therapeutics include biological agents as bevacizumab (Avastin), a monoclonal antibody against vascular endothelial growth factor (VEGF), and cetuximab (Erbitux), an inhibitor of epithelial growth factor receptor (EGFR). Although these biologicals have entered clinical routine due to their encouraging results, their effect has been shown to be limited due to adaptation or previously existing resistance of tumor cells. This has been clearly shown in the case of patients with mutations of K-ras, which lead to resistance against cetuximab. Therefore, several new pathways are currently investigated for therapeutic targeting in CRC. These include WNT-signaling, downstream mediators of EGFR as the mitogen-activated protein kinase (MAPK)- or the phosphatidylinositol 3-kinase (PI3K)-pathway, the hypoxia response system involving hypoxia inducible factor-1 (HIF-1), mechanisms of tumor development following chronic inflammation, and many others. This article will review new molecular targets for the treatment of CRC and discuss possible implications for clinical therapy.
Collapse
|
45
|
Tartaglia M, Zampino G, Gelb BD. Noonan syndrome: clinical aspects and molecular pathogenesis. Mol Syndromol 2010; 1:2-26. [PMID: 20648242 DOI: 10.1159/000276766] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 10/30/2009] [Indexed: 01/20/2023] Open
Abstract
Noonan syndrome (NS) is a relatively common, clinically variable and genetically heterogeneous developmental disorder characterized by postnatally reduced growth, distinctive facial dysmorphism, cardiac defects and variable cognitive deficits. Other associated features include ectodermal and skeletal defects, cryptorchidism, lymphatic dysplasias, bleeding tendency, and, rarely, predisposition to hematologic malignancies during childhood. NS is caused by mutations in the PTPN11, SOS1, KRAS, RAF1, BRAF and MEK1 (MAP2K1) genes, accounting for approximately 70% of affected individuals. SHP2 (encoded by PTPN11), SOS1, BRAF, RAF1 and MEK1 positively contribute to RAS-MAPK signaling, and possess complex autoinhibitory mechanisms that are impaired by mutations. Similarly, reduced GTPase activity or increased guanine nucleotide release underlie the aberrant signal flow through the MAPK cascade promoted by most KRAS mutations. More recently, a single missense mutation in SHOC2, which encodes a cytoplasmic scaffold positively controlling RAF1 activation, has been discovered to cause a closely related phenotype previously termed Noonan-like syndrome with loose anagen hair. This mutation promotes aberrantly acquired N-myristoylation of the protein, resulting in its constitutive targeting to the plasma membrane and dysregulated function. PTPN11, BRAF and RAF1 mutations also account for approximately 95% of LEOPARD syndrome, a condition which resembles NS phenotypically but is characterized by multiple lentigines dispersed throughout the body, café-au-lait spots, and a higher prevalence of electrocardiographic conduction abnormalities, obstructive cardiomyopathy and sensorineural hearing deficits. These recent discoveries demonstrate that the substantial phenotypic variation characterizing NS and related conditions can be ascribed, in part, to the gene mutated and even the specific molecular lesion involved.
Collapse
Affiliation(s)
- M Tartaglia
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome, Italy
| | | | | |
Collapse
|
46
|
|
47
|
Hostein I, Faur N, Primois C, Boury F, Denard J, Emile JF, Bringuier PP, Scoazec JY, Coindre JM. BRAF mutation status in gastrointestinal stromal tumors. Am J Clin Pathol 2010; 133:141-8. [PMID: 20023270 DOI: 10.1309/ajcppckga2qgbj1r] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors characterized by mutations of KIT or PDGFRA. The objectives of this study were to evaluate BRAF mutations in GISTs and then to correlate BRAF mutational status in the tumor with clinical parameters, with B-raf expression, and with activation of some cellular pathways. BRAF mutation was screened in 321 GISTs with 70 wild-type GISTs. BRAF V600E was detected in 9 (13%) of 70 wild-type GISTs. No mutations were detected in GISTs bearing KIT or PDGFRA mutations. BRAF V600E detection in the tumor does not induce a higher expression of the B-raf protein or the preferential activation of the p42/44 mitogen-activated protein kinase (MAPK) signaling pathway compared with GISTs without the BRAF mutation. In comparison with the GIST group with KIT or PDGFRA mutation or the wild-type GIST group without BRAF mutation, the wild-type GIST group with a BRAF mutation is not different in terms of B-raf expression or the p44/42 MAPK- or AKT-activated signaling pathway.
Collapse
|
48
|
Christoffersen T, Guren TK, Spindler KLG, Dahl O, Lønning PE, Gjertsen BT. Cancer therapy targeted at cellular signal transduction mechanisms: Strategies, clinical results, and unresolved issues. Eur J Pharmacol 2009; 625:6-22. [DOI: 10.1016/j.ejphar.2009.10.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 09/30/2009] [Accepted: 10/08/2009] [Indexed: 12/19/2022]
|
49
|
Urosevic J, Sum EYM, Moneo V, Drosten M, Dhawahir A, Becerra M, Carnero A, Barbacid M. Using cells devoid of RAS proteins as tools for drug discovery. Mol Carcinog 2009; 48:1038-47. [PMID: 19526460 DOI: 10.1002/mc.20555] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mutational activation of RAS proteins occurs in nearly 30% of all human tumors. To date direct pharmacological inhibition of RAS oncoproteins has not been possible. As a consequence, current strategies are focusing on the development of inhibitors that target those kinases acting downstream of RAS proteins, including those of the RAF/MEK/ERK and PI3K/AKT pathways. Most of these inhibitors have undesired off-target effects that mask the potential therapeutic effect of blocking their targeted kinases. To facilitate the screening of selective inhibitors, we have generated lines of mouse embryonic fibroblasts that lack endogenous Ras proteins. These cells proliferate due to ectopic expression of either Ras oncoproteins that selectively activate the Raf/Mek/Erk pathway such as H-Ras(G12V/D38E) or constitutively active kinases such as B-Raf and Mek1. These cell lines were exposed to inhibitors against the RAF, MEK, and AKT kinases as well as inhibitors of other kinases known to crosstalk with RAS signaling such as JNK and p38. Amongst all compounds tested, only the MEK inhibitors U0126 and PD0325901, showed the expected specificity pattern. Yet, PD0325901, but not U0126, was able to inhibit a cell line lacking Ras proteins that owed its proliferative properties to loss of p53. Thus, suggesting unexpected off-target activities for this compound. The use of cell lines whose proliferative properties exclusively depend on selective targets provide a novel strategy to analyze the specificity of selective inhibitors designed against molecular targets implicated in human cancer.
Collapse
Affiliation(s)
- Jelena Urosevic
- Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Choo EF, Driscoll JP, Feng J, Liederer B, Plise E, Randolph N, Shin Y, Wong S, Ran Y. Disposition of GDC-0879, a B-RAF kinase inhibitor in preclinical species. Xenobiotica 2009; 39:700-9. [PMID: 19552528 DOI: 10.1080/00498250902991827] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
1. The pharmacokinetics and disposition of GDC-0879, a small molecule B-RAF kinase inhibitor, was characterized in mouse, rat, dog, and monkey. 2. In mouse and monkey, clearance (CL) of GDC-0879 was moderate (18.7-24.3 and 14.5 +/- 2.1 ml min(-1) kg(-1), respectively), low in dog (5.84 +/- 1.06 ml min(-1) kg(-1)) and high in rat (86.9 +/- 14.2 ml min(-1) kg(-1)). The volume of distribution across species ranged from 0.49 to 1.9 l kg(-1). Mean terminal half-life values ranged from 0.28 h in rats to 2.97 h in dogs. Absolute oral bioavailability ranged from 18% in dog to 65% in mouse. 3. Plasma protein binding of GDC-0879 in mouse, rat, dog, monkey, and humans ranged from 68.8% to 81.9%. 4. In dog, the major ketone metabolite (G-030748) of GDC-0879 appeared to be formation rate-limited. 5. Based on assessment in dogs, the absorption of GDC-0879 appeared to be sensitive to changes in gut pH, food and salt form (solubililty), with approximately three- to four-fold change in areas under the curve (AUCs) observed.
Collapse
Affiliation(s)
- E F Choo
- Drug Metabolism and Pharmacokinetics Department, Genentech, Inc., South San Francisco, CA 94080, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|