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PTEN phosphatase inhibits metastasis by negatively regulating the Entpd5/IGF1R pathway through ATF6. iScience 2023; 26:106070. [PMID: 36824269 PMCID: PMC9942123 DOI: 10.1016/j.isci.2023.106070] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/01/2022] [Accepted: 01/23/2023] [Indexed: 01/27/2023] Open
Abstract
PTEN encodes a tumor suppressor with lipid and protein phosphatase activities whose dysfunction has been implicated in melanomagenesis; less is known about how its phosphatases regulate melanoma metastasis. We demonstrate that PTEN expression negatively correlates with metastatic progression in human melanoma samples and a PTEN-deficient mouse melanoma model. Wildtype PTEN expression inhibited melanoma cell invasiveness and metastasis in a dose-dependent manner, behaviors that specifically required PTEN protein phosphatase activity. PTEN phosphatase activity regulated metastasis through Entpd5. Entpd5 knockdown reduced metastasis and IGF1R levels while promoting ER stress. In contrast, Entpd5 overexpression promoted metastasis and enhanced IGF1R levels while reducing ER stress. Moreover, Entpd5 expression was regulated by the ER stress sensor ATF6. Altogether, our data indicate that PTEN phosphatase activity inhibits metastasis by negatively regulating the Entpd5/IGF1R pathway through ATF6, thereby identifying novel candidate therapeutic targets for the treatment of PTEN mutant melanoma.
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Moreno S, Maiques O, Barcelo C, Romero M, Santacana M, Gómez I, Cuevas D, Velasco A, Vea A, Macia A, Boix R, Valls J, Gatius S, Canti C, Matias-Guiu X, Soria X, Marti RM. Differential Immunoexpression of BRAF/V600E, Senescence Markers, PTEN, and T-type Calcium Channels in Acquired Naevi According to their Histopathological and Dermoscopic Classification. Acta Derm Venereol 2021; 101:adv00597. [PMID: 34643739 PMCID: PMC9455337 DOI: 10.2340/actadv.v101.361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BRAF/V600E mutation and other cell growth/growth-control mechanisms are involved in naevogenesis and melanomagenesis. Immunoexpression of BRAF/V600E and other molecules (p16, phosphatase and tensin homologue (PTEN), Ki67, hTERT and Cav3.1 and 3.2 calcium channels) were investigated in 80 histopathologically and dermoscopically classified acquired naevi. Regarding BRAF/V600E, dysplastic naevi showed lower immunostaining than common naevi, which was significant in comparison with intradermal naevi, which showed the highest BRAF/V600E histoscore. Junctional naevi showed the lowest BRAF/V600E levels. Globular/cobblestone and reticular dermoscopic patterns were consistently associated with high and low BRAF/V600E immunoexpression, respectively, but Zalaudek’s peripheral globule pattern (CR/PG) showed the highest BRAF/V600E immunoexpression. Among global patterns, the previously not investigated multicomponent pattern showed the lowest BRAF/V600E immunoexpression. Regarding the remaining biomarkers, new immunohistochemical features were found, in particular p16 and PTEN low expression in multicomponent pattern; and Ki67, hTERT and Cav.3.1 high expression in CR/PG. In conclusion, histopathology and dermoscopy provide complementary information regarding the biology of melanocytic naevi.
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Affiliation(s)
- Sara Moreno
- Department of Dermatology, Hospital Universitari Arnau de Vilanova, University of Lleida, IRBLleida, Avda Alcalde Rovira Roure 80, ES-25198 Lleida, Spain.
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Kwong LN, Davies MA. Navigating the therapeutic complexity of PI3K pathway inhibition in melanoma. Clin Cancer Res 2014; 19:5310-9. [PMID: 24089444 DOI: 10.1158/1078-0432.ccr-13-0142] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Melanoma is entering into an era of combinatorial approaches to build upon recent clinical breakthroughs achieved by novel single-agent therapies. One of the leading targets to emerge from the growing understanding of the molecular pathogenesis, heterogeneity, and resistance mechanisms of melanomas is the phosphoinositide 3-kinase (PI3K)-AKT pathway. Multiple genetic and epigenetic aberrations that activate this pathway have been identified in melanomas de novo and in acquired resistance models. These developments have been paralleled by the establishment of models for preclinical testing and the availability of compounds that target various effectors in the pathway. Thus, in addition to having a strong rationale for targeting, the PI3K-AKT pathway presents an immediate clinical opportunity. However, the development of effective strategies against this pathway must overcome several key challenges, including optimizing patient selection, overcoming feedback loops, and pathway cross-talk that can mediate resistance. This review discusses the current understanding and ongoing research about the PI3K-AKT pathway in melanoma and emerging strategies to achieve clinical benefit in patients by targeting it.
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Affiliation(s)
- Lawrence N Kwong
- Authors' Affiliations: Departments of Genomic Medicine, Melanoma Medical Oncology, and Systems Biology, University of Texas MD Anderson Cancer Center, Houston, Texas
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Firoozinia M, Zareian Jahromi M, Moghadamtousi SZ, Nikzad S, Abdul Kadir H. PIK3CA gene amplification and PI3K p110α protein expression in breast carcinoma. Int J Med Sci 2014; 11:620-5. [PMID: 24782652 PMCID: PMC4003548 DOI: 10.7150/ijms.8251] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 03/12/2014] [Indexed: 01/17/2023] Open
Abstract
A family of PI3Ks is the lipid kinases, which enhance intracellular pools of phosphatidyl inositol 3,4,5-tri-phosphate (PIP3) through phosphorylating its precursor. Amplifications and deletions of genes, as well as somatic missense of the PIK3CA gene have been described in many human cancer varieties, including of the brain, colon, liver, lung and stomach. Immunohistochemistry and Real-time quantitative PCR tests were used to determine the PIK3CA gene amplification (gene copy number) and to detect protein expression, respectively. The results obtained were analysed and the ratio of PIK3CA to β-actin gene copy number was calculated. Positive gene amplification of PIK3CA was appointed as a copy number of ≥4. Also, PI3K p110α protein expression was scored from 0 to 3+ and the scores of 2+ and 3+ were considered as positive for PI3K p110α protein expression. We studied 50 breast carcinoma samples for PI3K p110α protein expression and PIK3CA gene copy numbers. In general, 36 out of 50 (72%) breast carcinoma samples showed a significant increase in PIK3CA gene amplification. 12 out of 50 (24%) showed positive staining, and 38 out of 50 (76%) showed negative staining for PI3K p110α expression. We have identified no significant relationship between PIK3CA amplification, race (p= 0.630) and histological type (p=0. 731) in breast carcinoma, but correlation of PIK3CA amplification and age showed a significant relationship (p=0. 003) between them. No significant relationship has been identified in correlation of PI3K p110α protein expression compared to age (p=0. 284), race (p=0. 546) and histological type (p=0. 285). Amplification of PIK3CA was frequent in breast carcinoma and occurs in stages of breast carcinoma. Our result shows that there is a relationship between gene amplification and age in breast carcinoma. We suggest that PIK3CA is significant in breast tumorigenesis serve as a prevalent mechanism contributes to the oncogenic activation pathway of PIK3CA in breast cancer.
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Affiliation(s)
- Mohammad Firoozinia
- 1. Biomolecular Research Group, Biochemistry Program, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | - Soheil Zorofchian Moghadamtousi
- 1. Biomolecular Research Group, Biochemistry Program, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Sonia Nikzad
- 1. Biomolecular Research Group, Biochemistry Program, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Habsah Abdul Kadir
- 1. Biomolecular Research Group, Biochemistry Program, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Hauke RJ, Infante JR, Rubin MS, Shih KC, Arrowsmith ER, Hainsworth JD. Everolimus in combination with paclitaxel and carboplatin in patients with metastatic melanoma: a phase II trial of the Sarah Cannon Research Institute Oncology Research Consortium. Melanoma Res 2013; 23:468-73. [PMID: 23969699 DOI: 10.1097/cmr.0000000000000014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This phase II trial examined the efficacy and toxicity of first-line treatment with everolimus, paclitaxel, and carboplatin in patients with advanced melanoma. Seventy patients with metastatic or locally advanced unresectable melanoma who had been untreated previously with chemotherapy or targeted agents received first-line treatment with everolimus (5 mg, orally, daily), paclitaxel (175 mg/m, intravenous, every 3 weeks), and carboplatin (area under the curve 6.0, intravenous, every 3 weeks). Response to treatment was assessed every 6 weeks; responding and stable patients received six cycles of paclitaxel and carboplatin, and subsequently continued single-agent everolimus until disease progression or unacceptable toxicity. Twelve patients (17%) showed objective responses (all partial); an additional 27 patients showed measurable tumor shrinkage. After a median follow-up of 15 months, the median progression-free survival was 4.0 months (95% confidence interval 2.8-5.0 months); the median survival for the entire group was 10.1 months. Myelosuppression was the most common grade 3/4 toxicity; 70% of patients experienced at least one episode of grade 3/4 toxicity while on study. Although this regimen was active in the first-line treatment of advanced melanoma, there was no suggestion of improved efficacy when compared with previous results with paclitaxel/carboplatin alone. Further study of this combination is not recommended.
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Affiliation(s)
- Ralph J Hauke
- aNebraska Cancer Specialists, Omaha, Nebraska bSarah Cannon Research Institute cTennessee Oncology, PLLC, Nashville, Tennessee dFlorida Cancer Specialists, Fort Myers, Florida, USA
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Duffy K, Grossman D. The dysplastic nevus: from historical perspective to management in the modern era: part II. Molecular aspects and clinical management. J Am Acad Dermatol 2012; 67:19.e1-12; quiz 31-2. [PMID: 22703916 DOI: 10.1016/j.jaad.2012.03.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The dysplastic nevus is a discreet histologic entity that exhibits some clinical and histologic features overlapping with common nevi and melanoma. These overlapping features present a therapeutic challenge, and with a lack of accepted guidelines, the management of dysplastic nevi remains a controversial subject. Although some differences between dysplastic and common nevi can be detected at the molecular level, there are currently no established markers to predict biologic behavior. In part II of this continuing medical education article, we will review the molecular aspects of dysplastic nevi and their therapeutic implications. Our goal is to provide the clinician with an up-to-date understanding of this entity to facilitate clinical management of patients with nevi that have histologic dysplasia.
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Affiliation(s)
- Keith Duffy
- Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
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Aguissa-Touré AH, Li G. Genetic alterations of PTEN in human melanoma. Cell Mol Life Sci 2012; 69:1475-91. [PMID: 22076652 PMCID: PMC11114653 DOI: 10.1007/s00018-011-0878-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 10/13/2011] [Accepted: 10/24/2011] [Indexed: 12/31/2022]
Abstract
The PTEN gene is one of the most frequently inactivated tumor suppressor genes in sporadic cancers. Inactivating mutations and deletions of the PTEN gene are found in many types of cancers, including melanoma. However, the exact frequency of PTEN alteration in melanoma is unknown. In this study, we comprehensively reviewed 16 studies on PTEN genetic changes in melanoma cell lines and tumor biopsies. To date, 76 PTEN alterations have been reported in melanoma cell lines and 38 PTEN alterations in melanoma biopsies. The rate of PTEN alterations in melanoma cell lines, primary melanoma, and metastatic melanoma is 27.6, 7.3, and 15.2%, respectively. Three mutations were found in both melanoma cell lines and biopsies. These mutations are scattered throughout the gene, with the exception of exon 9. A mutational hot spot is found in exon 5, which encodes the phosphatase activity domain. Evidence is also presented to suggest that numerous homozygous deletions and missense variants exist in the PTEN transcript. Studying PTEN functions and implications of its mutations and other genes could provide insights into the precise nature of PTEN function in melanoma and additional targets for new therapeutic approaches.
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Affiliation(s)
- Almass-Houd Aguissa-Touré
- Department of Dermatology and Skin Science, Vancouver Coastal Health Research Institute, Jack Bell Research Centre, University of British Columbia, Vancouver, BC, Canada
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Lin K, Baritaki S, Militello L, Malaponte G, Bevelacqua Y, Bonavida B. The Role of B-RAF Mutations in Melanoma and the Induction of EMT via Dysregulation of the NF-κB/Snail/RKIP/PTEN Circuit. Genes Cancer 2010; 1:409-420. [PMID: 20827424 DOI: 10.1177/1947601910373795] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Melanoma is a highly metastatic cancer, and there are no current therapeutic modalities to treat this deadly malignant disease once it has metastasized. Melanoma cancers exhibit B-RAF mutations in up to 70% of cases. B-RAF mutations are responsible, in large part, for the constitutive hyperactivation of survival/antiapoptotic pathways such as the MAPK, NF-κB, and PI3K/AKT. These hyperactivated pathways regulate the expression of genes targeting the initiation of the metastatic cascade, namely, the epithelial to mesenchymal transition (EMT). EMT is the result of the expression of mesenchymal gene products such as fibronectin, vimentin, and metalloproteinases and the invasion and inhibition of E-cadherin. The above pathways cross-talk and regulate each other's activities and functions. For instance, the NF-κB pathway directly regulates EMT through the transcription of gene products involved in EMT and indirectly through the transcriptional up-regulation of the metastasis inducer Snail. Snail, in turn, suppresses the expression of the metastasis suppressor gene product Raf kinase inhibitor protein RKIP (inhibits the MAPK and the NF-κB pathways) as well as PTEN (inhibits the PI3K/AKT pathway). The role of B-RAF mutations in melanoma and their direct role in the induction of EMT are not clear. This review discusses the hypothesis that B-RAF mutations are involved in the dysregulation of the NF-κB/Snail/RKIP/PTEN circuit and in both the induction of EMT and metastasis. The therapeutic implications of the dysregulation of the above circuit by B-RAF mutations are such that they offer novel targets for therapeutic interventions in the treatment of EMT and metastasis.
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Affiliation(s)
- Kimberly Lin
- Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, Jonsson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA, USA
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Ibrahim N, Haluska FG. Molecular pathogenesis of cutaneous melanocytic neoplasms. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2009; 4:551-79. [PMID: 19400696 DOI: 10.1146/annurev.pathol.3.121806.151541] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Melanoma is the deadliest form of skin cancer without an effective treatment. An understanding of the genetic basis of melanoma has recently shed light on some of the mechanisms of melanomagenesis. This review explores the major genes involved in familial and sporadic cutaneous melanoma with an emphasis on CDKN2A, CDK4, MC1R, and MAPK pathway targets (e.g., RAS and BRAF), apoptosis regulators (e.g., BCL-2, AKT, and APAF-1), and the tumor-suppressor genes TP53 and PTEN. New directions for therapeutics based on our current knowledge of the genes implicated in melanoma are also discussed.
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Affiliation(s)
- Nageatte Ibrahim
- Massachusetts General Hospital Cancer Center, Boston, MA 02114, USA.
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Aziz SA, Davies M, Pick E, Zito C, Jilaveanu L, Camp RL, Rimm DL, Kluger Y, Kluger HM. Phosphatidylinositol-3-kinase as a therapeutic target in melanoma. Clin Cancer Res 2009; 15:3029-36. [PMID: 19383818 DOI: 10.1158/1078-0432.ccr-08-2768] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Phosphatidylinositol-3 kinases (PI3K) are critical for malignant cellular processes including growth, proliferation, and survival, and are targets of drugs in clinical development. We assessed expression of PI3K in melanomas and nevi, and studied associations between PI3K pathway members and in vitro response to a PI3K inhibitor, LY294002. EXPERIMENTAL DESIGN Using Automated Quantitative Analysis, we quantified expression of p85 and p110alpha subunits in 540 nevi and 523 melanomas. We determined the IC(50) for LY294002 for 11 melanoma cell lines and, using reverse phase protein arrays, assessed the association between levels of PI3K pathway members and sensitivity to LY294002. RESULTS p85 and p110alpha tend to be coexpressed (P < 0.0001); expression was higher in melanomas than nevi (P < 0.0001) for both subunits, and higher in metastatic than primary melanomas for p85 (P < 0.0001). Although phospho-Akt (pAkt) levels decreased in all cell lines treated with LY294002, sensitivity was variable. We found no association by t tests between baseline p85, p110alpha, and pAkt levels and sensitivity to LY294002, whereas pS6 Ser(235) and Ser(240) were lower in the more resistant cell lines (P = 0.01 and P = 0.004, respectively). CONCLUSIONS Expression of p85 and p110alpha subunits is up-regulated in melanoma, indicating that PI3K is a good drug target. Pretreatment pS6 levels correlated with sensitivity to the PI3K inhibitor, LY294002, whereas PI3K and pAkt did not, suggesting that full activation of the PI3K pathway is needed for sensitivity to PI3K inhibition. pS6 should be evaluated as a predictor of response in melanoma patients treated with PI3K inhibitors, as these drugs enter clinical trials.
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Affiliation(s)
- Saadia A Aziz
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
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11
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Gould Rothberg BE, Bracken MB, Rimm DL. Tissue biomarkers for prognosis in cutaneous melanoma: a systematic review and meta-analysis. J Natl Cancer Inst 2009; 101:452-74. [PMID: 19318635 DOI: 10.1093/jnci/djp038] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In the clinical management of early-stage cutaneous melanoma, it is critical to determine which patients are cured by surgery alone and which should be treated with adjuvant therapy. To assist in this decision, many groups have made an effort to use molecular information. However, although there are hundreds of studies that have sought to assess the potential prognostic value of molecular markers in predicting the course of cutaneous melanoma, at this time, no molecular method to improve risk stratification is part of recommended clinical practice. To help understand this disconnect, we conducted a systematic review and meta-analysis of the published literature that reported immunohistochemistry-based protein biomarkers of melanoma outcome. Three parallel search strategies were applied to the PubMed database through January 15, 2008, to identify cohort studies that reported associations between immunohistochemical expression and survival outcomes in melanoma that conformed to the REMARK criteria. Of the 102 cohort studies, we identified only 37 manuscripts, collectively describing 87 assays on 62 distinct proteins, which met all inclusion criteria. Promising markers that emerged included melanoma cell adhesion molecule (MCAM)/MUC18 (all-cause mortality [ACM] hazard ratio [HR] = 16.34; 95% confidence interval [CI] = 3.80 to 70.28), matrix metalloproteinase-2 (melanoma-specific mortality [MSM] HR = 2.6; 95% CI = 1.32 to 5.07), Ki-67 (combined ACM HR = 2.66; 95% CI = 1.41 to 5.01), proliferating cell nuclear antigen (ACM HR = 2.27; 95% CI = 1.56 to 3.31), and p16/INK4A (ACM HR = 0.29; 95% CI = 0.10 to 0.83, MSM HR = 0.4; 95% CI = 0.24 to 0.67). We further noted incomplete adherence to the REMARK guidelines: 14 of 27 cohort studies that failed to adequately report their methods and nine studies that failed to either perform multivariable analyses or report their risk estimates were published since 2005.
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Lo RS, Witte ON. Transforming growth factor-beta activation promotes genetic context-dependent invasion of immortalized melanocytes. Cancer Res 2008; 68:4248-57. [PMID: 18519684 DOI: 10.1158/0008-5472.can-07-5671] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Accumulation of distinct sets of genetic/epigenetic alterations is thought to contribute to stepwise progression of human cutaneous melanomas. We found evidence of frequent tumor cell autonomous transforming growth factor-beta (TGF-beta) signal activation in both premalignant and malignant stages of human cutaneous melanoma histogenesis and investigated its potential causative roles using human organotypic skin cultures. PTEN deficiency and Braf activation, two common coincident genetic alterations found in primary cutaneous melanomas, were first introduced into human melanocytes previously immortalized by the SV40 large T antigen and telomerase. These changes individually supported anchorage-independent growth and conferred benign, hyperplastic growth in a skin-like environment. In addition, PTEN deficiency combined with Braf activation together induced a melanoma in situ-like phenotype without dermal invasion. Further addition of cell autonomous TGF-beta activation in the context of PTEN deficiency and Braf activation promoted dermal invasion in skin cultures without significantly promoting proliferation in vitro and in vivo. This proinvasive phenotype of cell autonomous TGF-beta activation is genetic context-dependent, as hyperactivating the TGF-beta type I receptor without PTEN deficiency and Braf activation failed to induce an invasive behavior. Evidence of genetic interactions among PTEN deficiency, Braf activation, and cell autonomous TGF-beta activation shows that distinct stages of human melanoma are genetically tractable in the proper tissue architecture.
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Affiliation(s)
- Roger S Lo
- Division of Dermatology/Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
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13
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Haluska F, Pemberton T, Ibrahim N, Kalinsky K. The RTK/RAS/BRAF/PI3K pathways in melanoma: biology, small molecule inhibitors, and potential applications. Semin Oncol 2008; 34:546-54. [PMID: 18083378 DOI: 10.1053/j.seminoncol.2007.09.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The discovery of mutations in the BRAF signaling molecule in a large proportion of cutaneous melanomas immediately suggested the prospect of effective therapies for this disease. The most appealing initial target has been BRAF itself, as most mutations involve a single residue in the kinase domain of the protein. But the identification of the high mutation rate in this signaling intermediate also suggests that other molecules up- and downstream of BRAF might be productively targeted. Indeed, several receptor tyrosine kinases, as well as RAS, are mutated in a small number of melanoma cases. Moreover, genetic alterations in the phosphotidylinositol-3-kinase (PI3K) pathway, especially in PTEN, suggest that this route also poses opportunities for therapeutic exploitation. We will review here the genetic evidence suggesting the utility of targets on these pathways. We will also summarize the recent clinical data that have accumulated from initial trials designed to test BRAF inhibition and targeting of other molecules. Finally, we provide an overview of molecules entering the clinic and soon to be tested in clinical studies, as well as strategies for their employment as monotherapy and in combinations.
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Affiliation(s)
- Frank Haluska
- Molecular Oncology Research Institute, Tufts-New England Medical Center, Boston, MA 02111, USA.
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Abstract
Understanding regulatory pathways involved in melanoma development and progression has advanced significantly in recent years. It is now appreciated that melanoma is the result of complex changes in multiple signaling pathways that affect growth control, metabolism, motility and the ability to escape cell death programs. Here we review the major signaling pathways currently known to be deregulated in melanoma with an implication to its development and progression. Among these pathways are Ras, B-Raf, MEK, PTEN, phosphatidylinositol-3 kinase (PI3Ks) and Akt which are constitutively activated in a significant number of melanoma tumors, in most cases due to genomic change. Other pathways discussed in this review include the [Janus kinase/signal transducer and activator of transcription (JAK/STAT), transforming growth factor-beta pathways which are also activated in melanoma, although the underlying mechanism is not yet clear. As a paradigm for remodeled signaling pathways, melanoma also offers a unique opportunity for targeted drug development.
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Affiliation(s)
- Pablo Lopez-Bergami
- Signal Transduction Program, Burnham Institute for Medical Research, La Jolla, CA, USA
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