201
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Lampson BL, Kendall SD, Ancrile BB, Morrison MM, Shealy MJ, Barrientos KS, Crowe MS, Kashatus DF, White RR, Gurley SB, Cardona DM, Counter CM. Targeting eNOS in pancreatic cancer. Cancer Res 2012; 72:4472-82. [PMID: 22738914 DOI: 10.1158/0008-5472.can-12-0057] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mortality from pancreatic ductal adenocarcinoma cancer (PDAC) is among the highest of any cancer and frontline therapy has changed little in years. Activation of endothelial nitric oxide synthase (eNOS, NOS3, or NOS III) has been implicated recently in the pathogenesis of PDACs. In this study, we used genetically engineered mouse and human xenograft models to evaluate the consequences of targeting eNOS in PDACs. Genetic deficiency in eNOS limited the development of preinvasive pancreatic lesions and trended toward an extended lifespan in mice with advanced pancreatic cancer. These effects were also observed upon oral administration of the clinically evaluated NOS small molecule inhibitor N(G)-nitro-L-arginine methyl ester (l-NAME). Similarly, other transgenic models of oncogenic KRas-driven tumors responded to l-NAME treatment. Finally, these results were recapitulated in xenograft models of human pancreatic cancer, in which l-NAME was found to broadly inhibit tumorigenic growth. Taken together, our findings offer preclinical proof-of-principle to repurpose l-NAME for clinical investigations in treatment of PDACs and possibly other KRas-driven human cancers.
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Affiliation(s)
- Benjamin L Lampson
- Departments of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA
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202
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Ying H, Kimmelman AC, Lyssiotis CA, Hua S, Chu GC, Fletcher-Sananikone E, Locasale JW, Son J, Zhang H, Coloff JL, Yan H, Wang W, Chen S, Viale A, Zheng H, Paik JH, Lim C, Guimaraes AR, Martin ES, Chang J, Hezel AF, Perry SR, Hu J, Gan B, Xiao Y, Asara JM, Weissleder R, Wang YA, Chin L, Cantley LC, DePinho RA. Oncogenic Kras maintains pancreatic tumors through regulation of anabolic glucose metabolism. Cell 2012; 149:656-70. [PMID: 22541435 DOI: 10.1016/j.cell.2012.01.058] [Citation(s) in RCA: 1429] [Impact Index Per Article: 119.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 12/12/2011] [Accepted: 01/30/2012] [Indexed: 02/06/2023]
Abstract
Tumor maintenance relies on continued activity of driver oncogenes, although their rate-limiting role is highly context dependent. Oncogenic Kras mutation is the signature event in pancreatic ductal adenocarcinoma (PDAC), serving a critical role in tumor initiation. Here, an inducible Kras(G12D)-driven PDAC mouse model establishes that advanced PDAC remains strictly dependent on Kras(G12D) expression. Transcriptome and metabolomic analyses indicate that Kras(G12D) serves a vital role in controlling tumor metabolism through stimulation of glucose uptake and channeling of glucose intermediates into the hexosamine biosynthesis and pentose phosphate pathways (PPP). These studies also reveal that oncogenic Kras promotes ribose biogenesis. Unlike canonical models, we demonstrate that Kras(G12D) drives glycolysis intermediates into the nonoxidative PPP, thereby decoupling ribose biogenesis from NADP/NADPH-mediated redox control. Together, this work provides in vivo mechanistic insights into how oncogenic Kras promotes metabolic reprogramming in native tumors and illuminates potential metabolic targets that can be exploited for therapeutic benefit in PDAC.
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Affiliation(s)
- Haoqiang Ying
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
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203
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Jabbar SF, Park S, Schweizer J, Berard-Bergery M, Pitot HC, Lee D, Lambert PF. Cervical cancers require the continuous expression of the human papillomavirus type 16 E7 oncoprotein even in the presence of the viral E6 oncoprotein. Cancer Res 2012; 72:4008-16. [PMID: 22700879 DOI: 10.1158/0008-5472.can-11-3085] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High-risk human papillomaviruses (HPV), such as HPV-16, are etiologic agents of a variety of anogenital and oral malignancies, including nearly all cases of cervical cancer. Cervical cancers arising in transgenic mice that express HPV-16 E7 in an inducible manner require the continuous expression of E7 for their maintenance. However, in HPV-associated cancers in vivo, E6 and E7 invariably are coexpressed. In this study, we investigated whether cervical cancers rely on the continuous expression of E7 in the context of constitutively expressed E6. We placed the inducible HPV-16 E7 transgene onto a background in which HPV-16 E6 was constitutively expressed. In transgenic mice with high-grade cervical dysplastic lesions and cervical cancer, repressing the expression of E7 led to the regression of all cancers and the vast majority of high-grade dysplastic lesions. In addition, cervical cancers were occasionally observed in transgenic mice in which E7 was repressed and then reexpressed. Our findings indicate that even in the presence of constitutively expressed E6, the continuous expression of E7 is required for the maintenance of cervical cancers and most precancerous lesions. These data have important implications for the potential clinical use of drugs designed to inhibit the expression and/or function of E7 to treat HPV-associated cancers.
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Affiliation(s)
- Sean F Jabbar
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA
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204
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Abstract
Melanoma is often considered one of the most aggressive and treatment-resistant human cancers. It is a disease that, due to the presence of melanin pigment, was accurately diagnosed earlier than most other malignancies and that has been subjected to countless therapeutic strategies. Aside from early surgical resection, no therapeutic modality has been found to afford a high likelihood of curative outcome. However, discoveries reported in recent years have revealed a near avalanche of breakthroughs in the melanoma field-breakthroughs that span fundamental understanding of the molecular basis of the disease all the way to new therapeutic strategies that produce unquestionable clinical benefit. These discoveries have been born from the successful fruits of numerous researchers working in many-sometimes-related, although also distinct-biomedical disciplines. Discoveries of frequent mutations involving BRAF(V600E), developmental and oncogenic roles for the microphthalmia-associated transcription factor (MITF) pathway, clinical efficacy of BRAF-targeted small molecules, and emerging mechanisms underlying resistance to targeted therapeutics represent just a sample of the findings that have created a striking inflection in the quest for clinically meaningful progress in the melanoma field.
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Affiliation(s)
- Hensin Tsao
- Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
- The Wellman Center for Photomedicine, Boston, Massachusetts 02114, USA
| | - Lynda Chin
- Department of Genomic Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Levi A. Garraway
- Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
| | - David E. Fisher
- Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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205
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Sun Q, Burke JP, Phan J, Burns MC, Olejniczak ET, Waterson AG, Lee T, Rossanese OW, Fesik SW. Discovery of Small Molecules that Bind to K-Ras and Inhibit Sos-Mediated Activation. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201358] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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206
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Sun Q, Burke JP, Phan J, Burns MC, Olejniczak ET, Waterson AG, Lee T, Rossanese OW, Fesik SW. Discovery of small molecules that bind to K-Ras and inhibit Sos-mediated activation. Angew Chem Int Ed Engl 2012; 51:6140-3. [PMID: 22566140 DOI: 10.1002/anie.201201358] [Citation(s) in RCA: 363] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Indexed: 01/14/2023]
Affiliation(s)
- Qi Sun
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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207
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Abstract
Platelet-derived growth factor B (PDGF-B) is a growth factor promoting and regulating cell migration, proliferation, and differentiation, involved in both developmental processes and in maintaining tissue homeostasis under strict regulation. What are the implications of prolonged or uncontrolled growth factor signaling in vivo, and when does a growth factor such as PDGF-B become an oncogene? Under experimental conditions, PDGF-B induces proliferation and causes tumor induction. It is not known whether these tumors are strictly a PDGF-B-driven proliferation of cells or associated with secondary genetic events such as acquired mutations or methylation-mediated gene silencing promoting neoplasia. If PDGF-B-driven tumorigenesis was only cellular proliferation, associated changes in gene expression would thus be correlated with proliferation and not associated with secondary events involved in tumorigenesis and neoplastic transformation such as cycle delay, DNA damage response, and cell death. Changes in gene expression might be expected to be reversible, as is PDGF-B-driven proliferation under normal circumstances. Since PDGF signaling is involved in oligodendrocyte progenitor cell differentiation and maintenance, it is likely that PDGF-B stimulates proliferation of a pool of cells with that phenotype, and inhibition of PDGF-B signaling would result in reduced expression of oligodendrocyte-associated genes. More importantly, inhibition of PDGF signaling would be expected to result in reversion of genes induced by PDGF-B accompanied by a decrease in proliferation. However, if PDGF-B-driven tumorigenesis is more than simply a proliferation of cells, inhibition of PDGF signaling may not reverse gene expression or halt proliferation. These fundamental questions concerning PDGF-B as a potential oncogene have not been resolved.
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Affiliation(s)
- Nanna Lindberg
- Department of Neurosurgery, Department of Cancer Biology and Genetics, and Brain Tumor Center, 1275 York Ave, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | - Eric C. Holland
- Department of Neurosurgery, Department of Cancer Biology and Genetics, and Brain Tumor Center, 1275 York Ave, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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208
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Tran PT, Bendapudi PK, Lin HJ, Choi P, Koh S, Chen J, Horng G, Hughes NP, Schwartz LH, Miller VA, Kawashima T, Kitamura T, Paik D, Felsher DW. Survival and death signals can predict tumor response to therapy after oncogene inactivation. Sci Transl Med 2012; 3:103ra99. [PMID: 21974937 DOI: 10.1126/scitranslmed.3002018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cancers can exhibit marked tumor regression after oncogene inhibition through a phenomenon called "oncogene addiction." The ability to predict when a tumor will exhibit oncogene addiction would be useful in the development of targeted therapeutics. Oncogene addiction is likely the consequence of many cellular programs. However, we reasoned that many of these inputs may converge on aggregate survival and death signals. To test this, we examined conditional transgenic models of K-ras(G12D)--or MYC-induced lung tumors and lymphoma combined with quantitative imaging and an in situ analysis of biomarkers of proliferation and apoptotic signaling. We then used computational modeling based on ordinary differential equations (ODEs) to show that oncogene addiction could be modeled as differential changes in survival and death intracellular signals. Our mathematical model could be generalized to different imaging methods (computed tomography and bioluminescence imaging), different oncogenes (K-ras(G12D) and MYC), and several tumor types (lung and lymphoma). Our ODE model could predict the differential dynamics of several putative prosurvival and prodeath signaling factors [phosphorylated extracellular signal-regulated kinase 1 and 2, Akt1, Stat3/5 (signal transducer and activator of transcription 3/5), and p38] that contribute to the aggregate survival and death signals after oncogene inactivation. Furthermore, we could predict the influence of specific genetic lesions (p53⁻/⁻, Stat3-d358L, and myr-Akt1) on tumor regression after oncogene inactivation. Then, using machine learning based on support vector machine, we applied quantitative imaging methods to human patients to predict both their EGFR genotype and their progression-free survival after treatment with the targeted therapeutic erlotinib. Hence, the consequences of oncogene inactivation can be accurately modeled on the basis of a relatively small number of parameters that may predict when targeted therapeutics will elicit oncogene addiction after oncogene inactivation and hence tumor regression.
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Affiliation(s)
- Phuoc T Tran
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
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209
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Schneider MR. Genetic mouse models for skin research: strategies and resources. Genesis 2012; 50:652-64. [PMID: 22467532 DOI: 10.1002/dvg.22029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/20/2012] [Accepted: 03/24/2012] [Indexed: 12/16/2022]
Abstract
A number of features contributed to establishing the mouse as the favorite model organism for skin research: the genetic and pathophysiological similarities to humans, the small size and relatively short reproductive period, meaning low maintenance costs, and the availability of sophisticated tools for manipulating the genome, gametes, and embryos. While initial studies depended on strains displaying skin abnormalities due to spontaneous genetic mutations, the availability of the transgenic and knockout technologies and their astonishing perfection during the last decades allowed the development of mouse lines permitting any imaginable genetic modification including gene inactivation, substitution, modification, or overexpression. While these technologies have already contributed to the functional analysis of several genes and processes related to skin research, continued progress requires understanding, awareness, and access to these mouse resources. This review will identify the strategies currently employed for the genetic manipulation of mice in skin research, and outline current resources and their limitations.
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Affiliation(s)
- Marlon R Schneider
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Munich, Germany.
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210
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Healey M, Crow MS, Molina CA. Ras-induced melanoma transformation is associated with the proteasomal degradation of the transcriptional repressor ICER. Mol Carcinog 2012; 52:692-704. [DOI: 10.1002/mc.21908] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 02/16/2012] [Accepted: 03/07/2012] [Indexed: 02/01/2023]
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211
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Eltawil KM, Renfrew PD, Molinari M. Meta-analysis of phase III randomized trials of molecular targeted therapies for advanced pancreatic cancer. HPB (Oxford) 2012; 14:260-8. [PMID: 22404265 PMCID: PMC3371213 DOI: 10.1111/j.1477-2574.2012.00441.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES For patients with unresectable pancreatic cancer (PC), the efficacy and safety of molecular targeted agents (MTAs) in combination with gemcitabine are still unclear. Published randomized controlled trials (RCTs) have reported conflicting results. This study aimed to conduct a systematic review of the literature and to perform a meta-analysis if appropriate. METHODS Seven electronic databases were searched using a standard technique to November 2011 without restriction on publication status or language. The primary aim was to assess overall survival (OS). Secondary aims were to assess progression-free survival (PFS), overall response rates (ORRs) and grade 3, 4 and 5 toxicities. A random-effects model was used for the meta-analysis. RESULTS Seven Phase III RCTs were identified; 1981 patients were treated with MTAs and gemcitabine, and 1992 patients received gemcitabine with or without placebo. No statistically significant difference in OS was found between the two groups [hazard ratio (HR) = 0.93, 95% confidence interval (CI) 0.85-1.02; P = 0.13]. The addition of MTAs improved PFS (HR = 0.86, 95% CI 0.79-0.93; P = 0.000) and ORR (odds ratio 1.35, 95% CI 1.05-1.74; P = 0.01). However, these benefits were accompanied by significantly higher toxicity (P = 0.001). CONCLUSIONS The findings of this study suggest that the palliation of PC with gemcitabine and MTAs does not provide a significant survival benefit and is associated with increased grade 3 and 4 toxicities.
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Affiliation(s)
- Karim M Eltawil
- Department of Surgery, Queen Elizabeth II Health Sciences Center, Dalhousie University, Halifax, NS, Canada
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212
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213
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Abstract
Melanoma, the most aggressive form of skin cancer, has increased in incidence more rapidly than any other cancer. The completion of the human genome project and advancements in genomics technologies has allowed us to investigate genetic alterations of melanoma at a scale and depth that is unprecedented. Here, we survey the history of the different approaches taken to understand the genomics of melanoma - from early candidate genes, to gene families, to genome-wide studies. The new era of whole-exome and whole-genome sequencing has paved the way for an in-depth understanding of melanoma biology, identification of new therapeutic targets, and development of novel personalized therapies for melanoma.
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Affiliation(s)
- Vijay Walia
- The Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Euphemia W. Mu
- Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jimmy C. Lin
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA
| | - Yardena Samuels
- The Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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214
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Melanoma-induced immunosuppression and its neutralization. Semin Cancer Biol 2012; 22:319-26. [PMID: 22349515 DOI: 10.1016/j.semcancer.2012.02.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 02/06/2012] [Indexed: 02/08/2023]
Abstract
Malignant melanoma is characterized by a rapid progression, metastasis to distant organs, and resistance to chemo- and radiotherapy. Well-defined immunogenic capacities of melanoma cells should allow a successful application of different immunotherapeutic strategies. However, the overall results of immunotherapeutic clinical studies are not satisfactory. These paradoxical observations are supposed to be due to the profound immunosuppression mediated by different mechanisms dealing with alterations in tumor and surrounding stroma cells. Melanoma microenvironment has been characterized by a remarkable accumulation of highly immunosuppressive regulatory leucocytes, in particular, myeloid-derived suppressor cells (MDSCs). Their migration, retention and high activity in the tumor lesions have been demonstrated to be induced by chronic inflammatory conditions developing in the tumor microenvironment and characterized by the long-term secretion of various inflammatory mediators (cytokines, chemokines, growth factors, reactive oxygen and nitrogen species, prostaglandins etc.) leading to further cancer progression. Here, we discuss the role of chronic inflammation in the recruitment and activation of MDSCs in melanoma lesions as well as therapeutic approaches of MDSC targeting to overcome tumor immunosuppressive microenvironment induced by chronic inflammation and enhance the efficiency of melanoma immunotherapies.
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215
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Bachireddy P, Rakhra K, Felsher DW. Immunology in the clinic review series; focus on cancer: multiple roles for the immune system in oncogene addiction. Clin Exp Immunol 2012; 167:188-94. [PMID: 22235994 PMCID: PMC3278684 DOI: 10.1111/j.1365-2249.2011.04514.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Despite complex genomic and epigenetic abnormalities, many cancers are irrevocably dependent on an initiating oncogenic lesion whose restoration to a normal physiological activation can elicit a dramatic and sudden reversal of their neoplastic properties. This phenomenon of the reversal of tumorigenesis has been described as oncogene addiction. Oncogene addiction had been thought to occur largely through tumour cell-autonomous mechanisms such as proliferative arrest, apoptosis, differentiation and cellular senescence. However, the immune system plays an integral role in almost every aspect of tumorigenesis, including tumour initiation, prevention and progression as well as the response to therapeutics. Here we highlight more recent evidence suggesting that oncogene addiction may be integrally dependent upon host immune-mediated mechanisms, including specific immune effectors and cytokines that regulate tumour cell senescence and tumour-associated angiogenesis. Hence, the host immune system is essential to oncogene addiction.
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Affiliation(s)
- P Bachireddy
- Department of Medicine, Brigham and Women's Hospital/Harvard Medical School, Boston, MA, USA
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216
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Abstract
The RAS oncogenes (HRAS, NRAS and KRAS) comprise the most frequently mutated class of oncogenes in human cancers (33%), thus stimulating intensive effort in developing anti-Ras inhibitors for cancer treatment. Despite intensive effort, to date, no effective anti-Ras strategies have successfully made it to the clinic. We present an overview of past and ongoing strategies to inhibit oncogenic Ras in cancer. Since approaches to directly target mutant Ras have not been successful, most efforts have focused on indirect approaches to block Ras membrane association or downstream effector signaling. While inhibitors of effector signaling are currently under clinical evaluation, genome-wide unbiased genetic screens have identified novel directions for future anti-Ras drug discovery.
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217
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Murugan AK, Munirajan AK, Tsuchida N. Ras oncogenes in oral cancer: the past 20 years. Oral Oncol 2012; 48:383-92. [PMID: 22240207 DOI: 10.1016/j.oraloncology.2011.12.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Revised: 12/12/2011] [Accepted: 12/15/2011] [Indexed: 12/13/2022]
Abstract
Oral squamous cell carcinoma (OSCC) of head and neck is associated with high morbidity and mortality in both Western and Asian countries. Several risk factors for the development of oral cancer are very well established, including tobacco chewing, betel quid, smoking, alcohol drinking and human papilloma virus (HPV) infection. Apart from these risk factors, many genetic factors such as oncogenes, tumor suppressor genes and regulatory genes are identified to involve in oral carcinogenesis with these risk factors dependent and independent manner. Ras is one of the most frequently genetically deregulated oncogene in oral cancer. In this review, we analyze the past 22years of literature on genetic alterations such as mutations and amplifications of the isoforms of the ras oncogene in oral cancer. Further, we addressed the isoform-specific role of the ras in oral carcinogenesis. We also discussed how targeting the Akt and MEK, downstream effectors of the PI3K/Akt and MAPK pathways, respectively, would probably pave the possible molecular therapeutic target for the ras driven tumorigenesis in oral cancer. Analysis of these ras isoforms may critically enlighten specific role of a particular ras isoform in oral carcinogenesis, enhance prognosis and pave the way for isoform-specific molecular targeted therapy in OSCC.
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Affiliation(s)
- Avaniyapuram Kannan Murugan
- Department of Molecular Cellular Oncology and Microbiology, Tokyo Medical and Dental University, Tokyo, Japan.
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218
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Targeting the Cellular Signaling: BRAF Inhibition and Beyond for the Treatment of Metastatic Malignant Melanoma. Dermatol Res Pract 2011; 2012:259170. [PMID: 22216021 PMCID: PMC3246694 DOI: 10.1155/2012/259170] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 09/14/2011] [Indexed: 12/19/2022] Open
Abstract
Although advances in cytotoxic treatments have been obtained in several neoplasias, in metastatic melanoma there was no drug able to significantly change the natural history of the disease in the last 30 years. In the last decade, translational research identified important mechanisms in malignant transformation, invasion, and progression. Signaling pathways can be abnormally activated by oncogenes. The identification of oncogenic mutated kinases implicated in this process provides an opportunity for new target therapies. The melanoma dependence on BRAF-mutated kinase allowed the development of inhibitors that produced major responses in clinical trials. This is the beginning of a novel class of drugs in metastatic melanoma; the identification of the transduction signaling networking and other “druggable” kinases is in active research. In this paper, we discuss the ongoing research on cellular signaling inhibition, resistance mechanisms, and strategies to overcome treatment failure.
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219
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Anders K, Buschow C, Charo J, Blankenstein T. Depot formation of doxycycline impairs Tet-regulated gene expression in vivo. Transgenic Res 2011; 21:1099-107. [PMID: 22167485 DOI: 10.1007/s11248-011-9580-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 11/30/2011] [Indexed: 01/26/2023]
Abstract
The tetracycline (Tet) system is widely used for regulation of gene expression in vitro and in vivo. We constructed C57BL/6 transgenic mice (rtTA-CM2) with strong and ubiquitous reverse transactivator (rtTA2(S)-M2) gene expression. rtTA-CM2 mice were crossed to Tet-responsive reporter mice (LC-1) conditionally expressing the firefly luciferase (FLuc) gene under control of a Tet-responsive element, which allowed sensitive quantification of the transactivator activity by bioluminescent imaging. Following doxycycline (dox) application, up to 10(5)-fold increase in BL signal was measured. rtTA activity was inducible in most analyzed organs. After dox withdrawal the BL signal decreased significantly but did not disappear completely, most likely due to a dox depot formation in vivo. The residual dox was sufficient to partly down-regulate a Tet-off controlled oncogene in a tumor transplantation experiment, resulting in reduced tumor growth. rtTA-CM2 mice may be a useful tool to analyze the function of genes in various organs but also reveal that down-regulation of gene expression is not complete.
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MESH Headings
- Animals
- Antigens, Polyomavirus Transforming/genetics
- Antigens, Polyomavirus Transforming/metabolism
- Antineoplastic Agents/pharmacology
- Crosses, Genetic
- Doxycycline/pharmacology
- Drug Screening Assays, Antitumor/methods
- Founder Effect
- Gene Expression Regulation, Neoplastic
- Luciferases/genetics
- Luciferases/metabolism
- Luminescent Measurements
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Microinjections
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Oocytes/metabolism
- Promoter Regions, Genetic
- Simian virus 40/genetics
- Tandem Mass Spectrometry
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription, Genetic
- Transgenes
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Affiliation(s)
- Kathleen Anders
- Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
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220
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Anders K, Buschow C, Herrmann A, Milojkovic A, Loddenkemper C, Kammertoens T, Daniel P, Yu H, Charo J, Blankenstein T. Oncogene-targeting T cells reject large tumors while oncogene inactivation selects escape variants in mouse models of cancer. Cancer Cell 2011; 20:755-67. [PMID: 22172721 PMCID: PMC3658305 DOI: 10.1016/j.ccr.2011.10.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 05/23/2011] [Accepted: 10/18/2011] [Indexed: 12/22/2022]
Abstract
The genetic instability of cancer cells frequently causes drug resistance. We established mouse cancer models, which allowed targeting of an oncogene by drug-mediated inactivation or monospecific CD8(+) effector T (T(E)) cells. Drug treatment of genetically unstable large tumors was effective but selected resistant clones in the long term. In contrast, T(E) cells completely rejected large tumors (≥500 mm(3)), if the target antigen was cancer-driving and expressed in sufficient amounts. Although drug-mediated oncogene inactivation selectively killed the cancer cells and left the tumor vasculature intact, which likely facilitated survival and growth of resistant clones, T(E) cell treatment led to blood vessel destruction and probably "bystander" elimination of escape variants, which did not require antigen cross-presentation by stromal cells.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Polyomavirus Transforming/genetics
- Antigens, Polyomavirus Transforming/metabolism
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- CD8-Positive T-Lymphocytes/physiology
- CD8-Positive T-Lymphocytes/transplantation
- Cell Line, Tumor
- Drug Resistance, Neoplasm/genetics
- Fibrosarcoma/blood supply
- Fibrosarcoma/genetics
- Fibrosarcoma/metabolism
- Fibrosarcoma/therapy
- Genes, Reporter
- Genomic Instability
- Immunotherapy, Adoptive
- Interferon-gamma/metabolism
- Luciferases, Firefly/biosynthesis
- Luciferases, Firefly/genetics
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, SCID
- Molecular Sequence Data
- Neoplasm Transplantation
- Oncogenes
- Point Mutation
- Skin Transplantation
- Stomach Neoplasms/therapy
- Trans-Activators/genetics
- Tumor Escape/genetics
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Affiliation(s)
- Kathleen Anders
- Max-Delbrück-Center for Molecular Medicine, 13092 Berlin, Germany
| | - Christian Buschow
- Institute of Immunology, Charité Campus Benjamin Franklin, 12200 Berlin, Germany
| | - Andreas Herrmann
- Cancer Immunotherapeutics & Tumor Immunology, Beckman Research Institute, City of Hope Cancer Center, Duarte, CA 91010 USA
| | - Ana Milojkovic
- Department of Hematology, Oncology and Tumor Immunology, Charité, Campus Berlin Buch, 13092, Berlin, Germany
| | | | - Thomas Kammertoens
- Institute of Immunology, Charité Campus Benjamin Franklin, 12200 Berlin, Germany
| | - Peter Daniel
- Department of Hematology, Oncology and Tumor Immunology, Charité, Campus Berlin Buch, 13092, Berlin, Germany
| | - Hua Yu
- Cancer Immunotherapeutics & Tumor Immunology, Beckman Research Institute, City of Hope Cancer Center, Duarte, CA 91010 USA
| | - Jehad Charo
- Max-Delbrück-Center for Molecular Medicine, 13092 Berlin, Germany
| | - Thomas Blankenstein
- Max-Delbrück-Center for Molecular Medicine, 13092 Berlin, Germany
- Institute of Immunology, Charité Campus Benjamin Franklin, 12200 Berlin, Germany
- Correspondence:
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221
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Damsky WE, Curley DP, Santhanakrishnan M, Rosenbaum LE, Platt JT, Gould Rothberg BE, Taketo MM, Dankort D, Rimm DL, McMahon M, Bosenberg M. β-catenin signaling controls metastasis in Braf-activated Pten-deficient melanomas. Cancer Cell 2011; 20:741-54. [PMID: 22172720 PMCID: PMC3241928 DOI: 10.1016/j.ccr.2011.10.030] [Citation(s) in RCA: 281] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 08/04/2011] [Accepted: 10/27/2011] [Indexed: 11/17/2022]
Abstract
Malignant melanoma is characterized by frequent metastasis, however, specific changes that regulate this process have not been clearly delineated. Although it is well known that Wnt signaling is frequently dysregulated in melanoma, the functional implications of this observation are unclear. By modulating β-catenin levels in a mouse model of melanoma that is based on melanocyte-specific Pten loss and Braf(V600E) mutation, we demonstrate that β-catenin is a central mediator of melanoma metastasis to the lymph nodes and lungs. In addition to altering metastasis, β-catenin levels control tumor differentiation and regulate both MAPK/Erk and PI3K/Akt signaling. Highly metastatic tumors with β-catenin stabilization are very similar to a subset of human melanomas. Together these findings establish Wnt signaling as a metastasis regulator in melanoma.
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Affiliation(s)
- William E. Damsky
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06510, USA
- Department of Pathology, University of Vermont College of Medicine, Burlington, VT, 05405, USA
- Correspondence: ; , Phone: 203-737-3484, Fax: 203-785-7637
| | - David P. Curley
- Department of Pathology, University of Vermont College of Medicine, Burlington, VT, 05405, USA
- Department of Medicine, Brigham and Women’s Hospital, Boston, MA, 02115,USA
| | | | - Lara E. Rosenbaum
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - James T. Platt
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06510, USA
| | | | - Makoto M. Taketo
- Department of Pharmacology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - David Dankort
- Department of Biology, McGill University, Montreal, Quebec, H3G 0B1, Canada
| | - David L. Rimm
- Department of Pathology, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Martin McMahon
- Cancer Research Institute & Department of Cell and Molecular Pharmacology, Helen Diller Family of Comprehensive Cancer Center, University of California, San Francisco, CA, 94143, USA
| | - Marcus Bosenberg
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06510, USA
- Department of Pathology, Yale University School of Medicine, New Haven, CT, 06510, USA
- Correspondence: ; , Phone: 203-737-3484, Fax: 203-785-7637
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222
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Contassot E, Jankovic D, Schuler P, Preynat-Seauve O, Gehrke S, Kerl K, Beermann F, French LE. Carcinogen treatment in mouse selectively expressing activated N-Ras Q61K in melanocytes recapitulates metastatic cutaneous melanoma development. Pigment Cell Melanoma Res 2011; 25:275-8. [PMID: 22128787 DOI: 10.1111/j.1755-148x.2011.00944.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
The incidence of melanoma has significantly increased, and a better understanding of its pathogenesis and development of new therapeutic strategies are urgently needed. Here, we describe a murine model of metastatic cutaneous melanoma using C57BL/6 mice expressing a mutated human N-Ras gene under the control of a tyrosinase promoter (TyrRas). These mice were topically exposed to 7,12- dimethylbenzanthracene (DMBA) for brief exposure periods. Cutaneous melanoma developed at the site of exposure on average by 19 weeks of age and in 80% of mice. Importantly, as in humans, melanoma development was associated with subsequent metastasis to tumor-draining lymph nodes. Critically, such metastatic behavior is transplantable, as intradermal inoculation of melanoma cells from TyrRas-DMBA mice into non-transgenic mice led to the growth of melanoma and, again, metastasis to skin-draining lymph nodes. This metastatic melanoma model closely mimics human pathology and should be a useful tool for studying melanoma pathogenesis and developing new therapies.
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223
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Chakravarty D, Santos E, Ryder M, Knauf JA, Liao XH, West BL, Bollag G, Kolesnick R, Thin TH, Rosen N, Zanzonico P, Larson SM, Refetoff S, Ghossein R, Fagin JA. Small-molecule MAPK inhibitors restore radioiodine incorporation in mouse thyroid cancers with conditional BRAF activation. J Clin Invest 2011; 121:4700-11. [PMID: 22105174 DOI: 10.1172/jci46382] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 10/12/2011] [Indexed: 12/15/2022] Open
Abstract
Advanced human thyroid cancers, particularly those that are refractory to treatment with radioiodine (RAI), have a high prevalence of BRAF (v-raf murine sarcoma viral oncogene homolog B1) mutations. However, the degree to which these cancers are dependent on BRAF expression is still unclear. To address this question, we generated mice expressing one of the most commonly detected BRAF mutations in human papillary thyroid carcinomas (BRAF(V600E)) in thyroid follicular cells in a doxycycline-inducible (dox-inducible) manner. Upon dox induction of BRAF(V600E), the mice developed highly penetrant and poorly differentiated thyroid tumors. Discontinuation of dox extinguished BRAF(V600E) expression and reestablished thyroid follicular architecture and normal thyroid histology. Switching on BRAF(V600E) rapidly induced hypothyroidism and virtually abolished thyroid-specific gene expression and RAI incorporation, all of which were restored to near basal levels upon discontinuation of dox. Treatment of mice with these cancers with small molecule inhibitors of either MEK or mutant BRAF reduced their proliferative index and partially restored thyroid-specific gene expression. Strikingly, treatment with the MAPK pathway inhibitors rendered the tumor cells susceptible to a therapeutic dose of RAI. Our data show that thyroid tumors carrying BRAF(V600E) mutations are exquisitely dependent on the oncoprotein for viability and that genetic or pharmacological inhibition of its expression or activity is associated with tumor regression and restoration of RAI uptake in vivo in mice. These findings have potentially significant clinical ramifications.
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Affiliation(s)
- Debyani Chakravarty
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
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224
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Abstract
KRAS is a potent oncogene and is mutated in about 30% of all human cancers. However, the biological context of KRAS-dependent oncogenesis is poorly understood. Genetically engineered mouse models of cancer provide invaluable tools to study the oncogenic process, and insights from KRAS-driven models have significantly increased our understanding of the genetic, cellular, and tissue contexts in which KRAS is competent for oncogenesis. Moreover, variation among tumors arising in mouse models can provide insight into the mechanisms underlying response or resistance to therapy in KRAS-dependent cancers. Hence, it is essential that models of KRAS-driven cancers accurately reflect the genetics of human tumors and recapitulate the complex tumor-stromal intercommunication that is manifest in human cancers. Here, we highlight the progress made in modeling KRAS-dependent cancers and the impact that these models have had on our understanding of cancer biology. In particular, the development of models that recapitulate the complex biology of human cancers enables translational insights into mechanisms of therapeutic intervention in KRAS-dependent cancers.
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225
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Felsher DW. MYC Inactivation Elicits Oncogene Addiction through Both Tumor Cell-Intrinsic and Host-Dependent Mechanisms. Genes Cancer 2011; 1:597-604. [PMID: 21037952 DOI: 10.1177/1947601910377798] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Tumorigenesis is generally caused by genetic changes that activate oncogenes or inactivate tumor suppressor genes. The targeted inactivation of oncogenes can be associated with tumor regression through the phenomenon of oncogene addiction. One of the most common oncogenic events in human cancer is the activation of the MYC oncogene. The inactivation of MYC may be a general and effective therapy for human cancer. Indeed, it has been experimentally shown that the inactivation of MYC can result in dramatic and sustained tumor regression in lymphoma, leukemia, osteosarcoma, hepatocellular carcinoma, squamous carcinoma, and pancreatic carcinoma through a multitude of mechanisms, including proliferative arrest, terminal differentiation, cellular senescence, induction of apoptosis, and the shutdown of angiogenesis. Cell-autonomous and cell-dependent mechanisms have both been implicated, and recent results suggest a critical role for autocrine factors, including thrombospondin-1 and TGF-β. Hence, targeting the inactivation of MYC appears to elicit oncogene addiction and, thereby, tumor regression through both tumor cell-intrinsic and host-dependent mechanisms.
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Affiliation(s)
- Dean W Felsher
- Division of Oncology, Departments of Medicine and Pathology, Stanford University, Stanford, CA, USA
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226
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Castellano E, Downward J. RAS Interaction with PI3K: More Than Just Another Effector Pathway. Genes Cancer 2011; 2:261-74. [PMID: 21779497 DOI: 10.1177/1947601911408079] [Citation(s) in RCA: 519] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
RAS PROTEINS ARE SMALL GTPASES KNOWN FOR THEIR INVOLVEMENT IN ONCOGENESIS: around 25% of human tumors present mutations in a member of this family. RAS operates in a complex signaling network with multiple activators and effectors, which allows them to regulate many cellular functions such as cell proliferation, differentiation, apoptosis, and senescence. Phosphatidylinositol 3-kinase (PI3K) is one of the main effector pathways of RAS, regulating cell growth, cell cycle entry, cell survival, cytoskeleton reorganization, and metabolism. However, it is the involvement of this pathway in human tumors that has attracted most attention. PI3K has proven to be necessary for RAS-induced transformation in vitro, and more importantly, mice with mutations in the PI3K catalytic subunit p110α that block its ability to interact with RAS are highly resistant to endogenous oncogenic KRAS-induced lung tumorigenesis and HRAS-induced skin carcinogenesis. These animals also have a delayed development of the lymphatic vasculature. Many PI3K inhibitors have been developed that are now in clinical trials. However, it is a complex pathway with many feedback loops, and interactions with other pathways make the results of its inhibition hard to predict. Combined therapy with another RAS-regulated pathway such as RAF/MEK/ERK may be the most effective way to treat cancer, at least in animal models mimicking the human disease. In this review, we will summarize current knowledge about how RAS regulates one of its best-known effectors, PI3K.
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Affiliation(s)
- Esther Castellano
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, London, UK
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227
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228
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Abstract
RAS proteins are essential components of signalling pathways that emanate from cell surface receptors. Oncogenic activation of these proteins owing to missense mutations is frequently detected in several types of cancer. A wealth of biochemical and genetic studies indicates that RAS proteins control a complex molecular circuitry that consists of a wide array of interconnecting pathways. In this Review, we describe how RAS oncogenes exploit their extensive signalling reach to affect multiple cellular processes that drive tumorigenesis.
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Affiliation(s)
- Yuliya Pylayeva-Gupta
- Department of Biochemistry, New York University School of Medicine, New York, New York 10016, USA
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229
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Zuber J, Rappaport AR, Luo W, Wang E, Chen C, Vaseva AV, Shi J, Weissmueller S, Fellmann C, Fellman C, Taylor MJ, Weissenboeck M, Graeber TG, Kogan SC, Vakoc CR, Lowe SW. An integrated approach to dissecting oncogene addiction implicates a Myb-coordinated self-renewal program as essential for leukemia maintenance. Genes Dev 2011; 25:1628-40. [PMID: 21828272 DOI: 10.1101/gad.17269211] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although human cancers have complex genotypes and are genomically unstable, they often remain dependent on the continued presence of single-driver mutations-a phenomenon dubbed "oncogene addiction." Such dependencies have been demonstrated in mouse models, where conditional expression systems have revealed that oncogenes able to initiate cancer are often required for tumor maintenance and progression, thus validating the pathways they control as therapeutic targets. Here, we implement an integrative approach that combines genetically defined mouse models, transcriptional profiling, and a novel inducible RNAi platform to characterize cellular programs that underlie addiction to MLL-AF9-a fusion oncoprotein involved in aggressive forms of acute myeloid leukemia (AML). We show that MLL-AF9 contributes to leukemia maintenance by enforcing a Myb-coordinated program of aberrant self-renewal involving genes linked to leukemia stem cell potential and poor prognosis in human AML. Accordingly, partial and transient Myb suppression precisely phenocopies MLL-AF9 withdrawal and eradicates aggressive AML in vivo without preventing normal myelopoiesis, indicating that strategies to inhibit Myb-dependent aberrant self-renewal programs hold promise as effective and cancer-specific therapeutics. Together, our results identify Myb as a critical mediator of oncogene addiction in AML, delineate relevant Myb target genes that are amenable to pharmacologic inhibition, and establish a general approach for dissecting oncogene addiction in vivo.
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Affiliation(s)
- Johannes Zuber
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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230
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Larue L, Davidson I. Front seat and back seat drivers of melanoma metastasis. Pigment Cell Melanoma Res 2011; 24:898-901. [PMID: 21910852 DOI: 10.1111/j.1755-148x.2011.00905.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Lionel Larue
- Institut Curie, Developmental Genetics of Melanocytes, CNRS UMR3347, INSERM U1021, Orsay, France.
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231
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Freije JMP, Fraile JM, López-Otín C. Protease addiction and synthetic lethality in cancer. Front Oncol 2011; 1:25. [PMID: 22655236 PMCID: PMC3356009 DOI: 10.3389/fonc.2011.00025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 08/17/2011] [Indexed: 01/03/2023] Open
Abstract
The “oncogene addiction” concept refers to the dependence of cancer cells on the function of the oncogenes responsible for their transformed phenotype, while the term “non-oncogene addiction” has been introduced to define the exacerbated necessity of the normal function of non-mutated genes. In this Perspective, we focus on the importance of proteolytic enzymes to maintain the viability of cancer cells and hypothesize that most, if not all, tumors present “addiction” to a number of proteolytic activities, which in turn may represent valuable targets of anti-cancer therapies, even without being mutated or over-expressed by the malignant cells.
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Affiliation(s)
- José M P Freije
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología, Universidad de Oviedo Oviedo, Spain
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232
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Ras-induced and extracellular signal-regulated kinase 1 and 2 phosphorylation-dependent isomerization of protein tyrosine phosphatase (PTP)-PEST by PIN1 promotes FAK dephosphorylation by PTP-PEST. Mol Cell Biol 2011; 31:4258-69. [PMID: 21876001 DOI: 10.1128/mcb.05547-11] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protein tyrosine phosphatase (PTP)-PEST is a critical regulator of cell adhesion and migration. However, the mechanism by which PTP-PEST is regulated in response to oncogenic signaling to dephosphorylate its substrates remains unclear. Here, we demonstrate that activated Ras induces extracellular signal-regulated kinase 1 and 2-dependent phosphorylation of PTP-PEST at S571, which recruits PIN1 to bind to PTP-PEST. Isomerization of the phosphorylated PTP-PEST by PIN1 increases the interaction between PTP-PEST and FAK, which leads to the dephosphorylation of FAK Y397 and the promotion of migration, invasion, and metastasis of v-H-Ras-transformed cells. These findings uncover an important mechanism for the regulation of PTP-PEST in activated Ras-induced tumor progression.
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233
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Gaudi S, Messina JL. Molecular bases of cutaneous and uveal melanomas. PATHOLOGY RESEARCH INTERNATIONAL 2011; 2011:159421. [PMID: 21876842 PMCID: PMC3159309 DOI: 10.4061/2011/159421] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/27/2011] [Accepted: 05/30/2011] [Indexed: 01/08/2023]
Abstract
Intensive research in recent years has begun to unlock the mysteries surrounding the molecular pathogenesis of melanoma, the deadliest of skin cancers. The high-penetrance, low-frequency susceptibility gene CDKN2A produces tumor suppressor proteins that function in concert with p53 and retinoblastoma protein to thwart melanomagenesis. Aberrant CDKN2A gene products have been implicated in a great many cases of familial cutaneous melanoma. Sporadic cases, on the other hand, often involve constitutive signal transduction along the mitogen-activated protein kinase (MAPK) pathway, with particular focus falling upon mutated RAS and RAF protooncogenes. The proliferative effects of the MAPK pathway may be complemented by the antiapoptotic signals of the PI3K/AKT pathway. After skin, melanoma most commonly affects the eye. Data for the constitutive activation of the MAPK pathway in uveal melanoma exists as well, however, not through mutations of RAS and RAF. Rather, evidence implicates the proto-oncogene GNAQ. In the following discussion, we review the major molecular pathways implicated in both familial and sporadic cutaneous melanomagenesis, the former accounting for approximately 10% of cases. Additionally, we discuss the molecular pathways for which preliminary evidence suggests a role in uveal melanomagenesis.
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Affiliation(s)
- Sudeep Gaudi
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, 12901 Bruce B. Downs Boulevard, MDC 11, Tampa, FL 33612, USA
| | - Jane L. Messina
- Department of Pathology, H. Lee Moffitt Cancer Center, 2nd Floor, 12902 Magnolia Dr., Tampa, FL 33612, USA
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234
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Scott KL, Nogueira C, Heffernan TP, van Doorn R, Dhakal S, Hanna JA, Min C, Jaskelioff M, Xiao Y, Wu CJ, Cameron LA, Perry SR, Zeid R, Feinberg T, Kim M, Woude GV, Granter SR, Bosenberg M, Chu GC, DePinho RA, Rimm DL, Chin L. Proinvasion metastasis drivers in early-stage melanoma are oncogenes. Cancer Cell 2011; 20:92-103. [PMID: 21741599 PMCID: PMC3176328 DOI: 10.1016/j.ccr.2011.05.025] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 04/28/2011] [Accepted: 05/28/2011] [Indexed: 12/20/2022]
Abstract
Clinical and genomic evidence suggests that the metastatic potential of a primary tumor may be dictated by prometastatic events that have additional oncogenic capability. To test this "deterministic" hypothesis, we adopted a comparative oncogenomics-guided function-based strategy involving: (1) comparison of global transcriptomes of two genetically engineered mouse models with contrasting metastatic potential, (2) genomic and transcriptomic profiles of human melanoma, (3) functional genetic screen for enhancers of cell invasion, and (4) evidence of expression selection in human melanoma tissues. This integrated effort identified six genes that are potently proinvasive and oncogenic. Furthermore, we show that one such gene, ACP5, confers spontaneous metastasis in vivo, engages a key pathway governing metastasis, and is prognostic in human primary melanomas.
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Affiliation(s)
- Kenneth L. Scott
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Cristina Nogueira
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Institute of Molecular Pathology and Immunology of the University of Porto, (IPATIMUP)/Medical Faculty, University of Porto, Porto, Portugal
| | - Timothy P. Heffernan
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Remco van Doorn
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Dermatology, Leiden University Medical Center, Leiden, the Netherlands
| | - Sabin Dhakal
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jason A. Hanna
- Department of Pathology, Yale University Medical School, New Haven, CT, USA
| | - Chengyin Min
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Mariela Jaskelioff
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Yonghong Xiao
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Chang-Jiun Wu
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Lisa A. Cameron
- Confocal and Light Microscopy Core, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Samuel R. Perry
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Rhamy Zeid
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Tamar Feinberg
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Minjung Kim
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | | | - Scott R. Granter
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Marcus Bosenberg
- Department of Pathology, Yale University Medical School, New Haven, CT, USA
| | - Gerald C. Chu
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ronald A. DePinho
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - David L. Rimm
- Department of Pathology, Yale University Medical School, New Haven, CT, USA
| | - Lynda Chin
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Dermatology, Harvard Medical School, Boston, MA, USA
- Correspondence should be addressed to LC:
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235
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Sacco E, Metalli D, Spinelli M, Manzoni R, Samalikova M, Grandori R, Morrione A, Traversa S, Alberghina L, Vanoni M. Novel RasGRF1-derived Tat-fused peptides inhibiting Ras-dependent proliferation and migration in mouse and human cancer cells. Biotechnol Adv 2011; 30:233-43. [PMID: 21620943 DOI: 10.1016/j.biotechadv.2011.05.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
Abstract
Mutations of RAS genes are critical events in the pathogenesis of different human tumors and Ras proteins represent a major clinical target for the development of specific inhibitors to use as anticancer agents. Here we present RasGRF1-derived peptides displaying both in vitro and in vivo Ras inhibitory properties. These peptides were designed on the basis of the down-sizing of dominant negative full-length RasGRF1 mutants. The over-expression of these peptides can revert the phenotype of K-RAS transformed mouse fibroblasts to wild type, as monitored by several independent biological readouts, including Ras-GTP intracellular levels, ERK activity, morphology, proliferative potential and anchorage independent growth. Fusion of the RasGRF1-derived peptides with the Tat protein transduction domain allows their uptake into mammalian cells. Chemically synthesized Tat-fused peptides, reduced to as small as 30 residues on the basis of structural constraints, retain Ras inhibitory activity. These small peptides interfere in vitro with the GEF catalyzed nucleotide dissociation and exchange on Ras, reduce cell proliferation of K-RAS transformed mouse fibroblasts, and strongly reduce Ras-dependent IGF-I-induced migration and invasion of human bladder cancer cells. These results support the use of RasGRF1-derived peptides as model compounds for the development of Ras inhibitory anticancer agents.
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Affiliation(s)
- Elena Sacco
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy.
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236
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Chin L, Andersen JN, Futreal PA. Cancer genomics: from discovery science to personalized medicine. Nat Med 2011; 17:297-303. [PMID: 21383744 DOI: 10.1038/nm.2323] [Citation(s) in RCA: 384] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent advances in genome technologies and the ensuing outpouring of genomic information related to cancer have accelerated the convergence of discovery science and clinical medicine. Successful examples of translating cancer genomics into therapeutics and diagnostics reinforce its potential to make possible personalized cancer medicine. However, the bottlenecks along the path of converting a genome discovery into a tangible clinical endpoint are numerous and formidable. In this Perspective, we emphasize the importance of establishing the biological relevance of a cancer genomic discovery in realizing its clinical potential and discuss some of the major obstacles to moving from the bench to the bedside.
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Affiliation(s)
- Lynda Chin
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
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237
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Markell LM, Masiuk KE, Blazanin N, Glick AB. Pharmacologic inhibition of ALK5 causes selective induction of terminal differentiation in mouse keratinocytes expressing oncogenic HRAS. Mol Cancer Res 2011; 9:746-56. [PMID: 21521744 DOI: 10.1158/1541-7786.mcr-11-0112] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
TGFβ has both tumor suppressive and oncogenic roles in cancer development. We previously showed that SB431542 (SB), a small molecule inhibitor of the TGFβ type I receptor (ALK5) kinase, suppressed benign epidermal tumor formation but enhanced malignant conversion. Here, we show that SB treatment of primary K5rTA/tetORASV12G bitransgenic keratinocytes did not alter HRASV12G-induced keratinocyte hyperproliferation. However, continuous SB treatment significantly enhanced HRASV12G-induced cornified envelope formation and cell death linked to increased expression of enzymes transglutaminase (TGM) 1 and TGM3 and constituents of the cornified envelope small proline-rich protein (SPR) 1A and SPR2H. In contrast, TGFβ1 suppressed cornified envelope formation in HRASV12G keratinocytes. Similar results were obtained in HRASV12G transgenic mice treated topically with SB or by coexpressing TGFβ1 and HRASV12G in the epidermis. Despite significant cell death, SB-resistant HRASV12G keratinocytes repopulated the primary culture that had overcome HRas-induced senescence. These cells expressed reduced levels of p16(ink4a) and were growth stimulated by SB but remained sensitive to a calcium-induced growth arrest. Together these results suggest that differential responsiveness to cornification may represent a mechanism by which pharmacologic blockade of TGFβ signaling can inhibit the outgrowth of preneoplastic lesions but may cause a more progressed phenotype in a separate keratinocyte population.
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Affiliation(s)
- Lauren Mordasky Markell
- The Pennsylvania State University, 201 Life Sciences Building, University Park, PA 16802, USA
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238
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Abstract
Genetically engineered mouse models have significantly contributed to our understanding of cancer biology. They have proven to be useful in validating gene functions, identifying novel cancer genes and tumor biomarkers, gaining insight into the molecular and cellular mechanisms underlying tumor initiation and multistage processes of tumorigenesis, and providing better clinical models in which to test novel therapeutic strategies. However, mice still have significant limitations in modeling human cancer, including species-specific differences and inaccurate recapitulation of de novo human tumor development. Future challenges in mouse modeling include the generation of clinically relevant mouse models that recapitulate the molecular, cellular, and genomic events of human cancers and clinical response as well as the development of technologies that allow for efficient in vivo imaging and high-throughput screening in mice.
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Affiliation(s)
- Dong-Joo Cheon
- Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA
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239
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Galluzzi L, Vitale I, Kroemer G. Past, present, and future of molecular and cellular oncology. Front Oncol 2011; 1:1. [PMID: 22655224 PMCID: PMC3356131 DOI: 10.3389/fonc.2011.00001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 03/11/2011] [Indexed: 12/18/2022] Open
Abstract
In the last 20 years, the field of cellular and molecular oncology has been born and has moved its first steps, with an increasingly rapid pace. Hundreds of oncogenic and oncosuppressive signaling cascades have been characterized, facilitating the development of an ever more refined and variegated arsenal of diagnostic and therapeutic weapons. Furthermore, several cancer-specific features and processes have been identified that constitute promising therapeutic targets. For instance, it has been demonstrated that microRNAs can play a critical role in oncogenesis and tumor suppression. Moreover, it turned out that tumor cells frequently exhibit an extensive metabolic rewiring, can behave in a stem cell-like fashion (and hence sustain tumor growth), often constitutively activate stress response pathways that allow them to survive, can react to therapy by engaging in non-apoptotic cell death programs, and sometimes die while eliciting a tumor-specific immune response. In this Perspective article, we discuss the main issues generated by these discoveries that will be in the limelight of molecular and cellular oncology research for the next, hopefully few years.
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240
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McKinney AJ, Holmen SL. Animal models of melanoma: a somatic cell gene delivery mouse model allows rapid evaluation of genes implicated in human melanoma. CHINESE JOURNAL OF CANCER 2011; 30:153-62. [PMID: 21352692 PMCID: PMC4013311 DOI: 10.5732/cjc.011.10007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 01/10/2011] [Accepted: 01/26/2011] [Indexed: 01/13/2023]
Abstract
The increasing incidence and mortality associated with advanced stages of melanoma are cause for concern. Few treatment options are available for advanced melanoma and the 5-year survival rate is less than 15%. Targeted therapies may revolutionize melanoma treatment by providing less toxic and more effective strategies. However, maximizing effectiveness requires further understanding of the molecular alterations that drive tumor formation, progression, and maintenance, as well as elucidating the mechanisms of resistance. Several different genetic alterations identified in human melanoma have been recapitulated in mice. This review outlines recent progress made in the development of mouse models of melanoma and summarizes what these findings reveal about the human disease. We begin with a discussion of traditional models and conclude with the recently developed RCAS/TVA somatic cell gene delivery mouse model of melanoma.
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Affiliation(s)
- Andrea J McKinney
- Department of Drug and Target Discovery, Nevada Cancer Institute, Las Vegas, NV 89135, USA
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241
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Romano E, Schwartz GK, Chapman PB, Wolchock JD, Carvajal RD. Treatment implications of the emerging molecular classification system for melanoma. Lancet Oncol 2011; 12:913-22. [PMID: 21349766 DOI: 10.1016/s1470-2045(10)70274-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Melanoma is an aggressive disease with few standard treatment options. The conventional classification system for this disease is based on histological growth patterns, with division into four subtypes: superficial spreading, lentigo maligna, nodular, and acral lentiginous. Major limitations of this classification system are absence of prognostic importance and little correlation with treatment outcomes. Recent preclinical and clinical findings support the notion that melanoma is not one malignant disorder but rather a family of distinct molecular diseases. Incorporation of genetic signatures into the conventional histopathological classification of melanoma has great implications for development of new and effective treatments. Genes of the mitogen-associated protein kinase (MAPK) pathway harbour alterations sometimes identified in people with melanoma. The mutation Val600Glu in the BRAF oncogene (designated BRAF(V600E)) has been associated with sensitivity in vitro and in vivo to agents that inhibit BRAF(V600E) or MEK (a kinase in the MAPK pathway). Melanomas arising from mucosal, acral, chronically sun-damaged surfaces sometimes have oncogenic mutations in KIT, against which several inhibitors have shown clinical efficacy. Some uveal melanomas have activating mutations in GNAQ and GNA11, rendering them potentially susceptible to MEK inhibition. These findings suggest that prospective genotyping of patients with melanoma should be used increasingly as we work to develop new and effective treatments for this disease.
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Affiliation(s)
- Emanuela Romano
- Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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242
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Mellinghoff IK, Lassman AB, Wen PY. Signal transduction inhibitors and antiangiogenic therapies for malignant glioma. Glia 2011; 59:1205-12. [PMID: 21351155 DOI: 10.1002/glia.21137] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 12/08/2010] [Indexed: 11/09/2022]
Abstract
Detailed characterization of the cancer genome in a large number of primary human glioblastomas has identified recurrent alterations that result in deregulation of signal transduction pathways and are "druggable" with a growing number of small molecule pharmaceuticals. While many of these compounds have shown clinical activity in other human cancers harboring similar genetic alterations, the clinical experience in glioblastoma has been disappointing thus far with only rare and transient radiographic responses. Our understanding of drug resistance is confounded by the uncertainty of drug delivery across the blood brain barrier and the limited knowledge to what extent the growth of these tumors depends on any particular signaling pathway. This uncertainty is, at least in part, due to shortcomings in the current approach to evaluate signal transduction inhibitors in glioma patients, including drug testing in molecularly unselected patient populations, limited documentation of drug penetration and target inhibition in tumor tissue, and use of radiographic response criteria that may not be optimal for the evaluation of these compounds. © 2011 Wiley-Liss, Inc.
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Affiliation(s)
- Ingo K Mellinghoff
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, USA.
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243
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Functional characterization of human cancer-derived TRKB mutations. PLoS One 2011; 6:e16871. [PMID: 21379385 PMCID: PMC3040757 DOI: 10.1371/journal.pone.0016871] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 01/17/2011] [Indexed: 01/13/2023] Open
Abstract
Cancer originates from cells that have acquired mutations in genes critical for controlling cell proliferation, survival and differentiation. Often, tumors continue to depend on these so-called driver mutations, providing the rationale for targeted anticancer therapies. To date, large-scale sequencing analyses have revealed hundreds of mutations in human tumors. However, without their functional validation it remains unclear which mutations correspond to driver, or rather bystander, mutations and, therefore, whether the mutated gene represents a target for therapeutic intervention. In human colorectal tumors, the neurotrophic receptor TRKB has been found mutated on two different sites in its kinase domain (TRKBT695I and TRKBD751N). Another site, in the extracellular part of TRKB, is mutated in a human lung adenocarcinoma cell line (TRKBL138F). Lastly, our own analysis has identified one additional TRKB point mutation proximal to the kinase domain (TRKBP507L) in a human melanoma cell line. The functional consequences of all these point mutations, however, have so far remained elusive. Previously, we have shown that TRKB is a potent suppressor of anoikis and that TRKB-expressing cells form highly invasive and metastatic tumors in nude mice. To assess the functional consequences of these four TRKB mutations, we determined their potential to suppress anoikis and to form tumors in nude mice. Unexpectedly, both colon cancer-derived mutants, TRKBT695I and TRKBD751N, displayed reduced activity compared to that of wild-type TRKB. Consistently, upon stimulation with the TRKB ligand BDNF, these mutants were impaired in activating TRKB and its downstream effectors AKT and ERK. The two mutants derived from human tumor cell lines (TRKBL138F and TRKBP507L) were functionally indistinguishable from wild-type TRKB in both in-vitro and in-vivo assays. In conclusion, we fail to detect any gain-of-function of four cancer-derived TRKB point mutations.
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244
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Affiliation(s)
- William E Damsky
- Department of Dermatology, Yale School of Medicine, 15 York Street, New Haven, CT 06520, USA
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245
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Politi K, Pao W. How genetically engineered mouse tumor models provide insights into human cancers. J Clin Oncol 2011; 29:2273-81. [PMID: 21263096 DOI: 10.1200/jco.2010.30.8304] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Genetically engineered mouse models (GEMMs) of human cancer were first created nearly 30 years ago. These early transgenic models demonstrated that mouse cells could be transformed in vivo by expression of an oncogene. A new field emerged, dedicated to generating and using mouse models of human cancer to address a wide variety of questions in cancer biology. The aim of this review is to highlight the contributions of mouse models to the diagnosis and treatment of human cancers. Because of the breadth of the topic, we have selected representative examples of how GEMMs are clinically relevant rather than provided an exhaustive list of experiments. Today, as detailed here, sophisticated mouse models are being created to study many aspects of cancer biology, including but not limited to mechanisms of sensitivity and resistance to drug treatment, oncogene cooperation, early detection, and metastasis. Alternatives to GEMMs, such as chemically induced or spontaneous tumor models, are not discussed in this review.
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246
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Ilić N, Roberts TM. Comparing the roles of the p110α and p110β isoforms of PI3K in signaling and cancer. Curr Top Microbiol Immunol 2011; 347:55-77. [PMID: 20517719 DOI: 10.1007/82_2010_63] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phosphatidylinositol-3-kinases (PI3K) are a family of enzymes that act downstream of cell surface receptors leading to activation of multiple signaling pathways regulating cellular growth, proliferation, motility, and survival. To date, most research efforts have focused on a group of PI3K-family enzymes termed class I, of which the most studied member is PI3Kα. PI3Kα is an oncogene frequently mutated in human cancer, as is the chief negative regulator of the pathway, the tumor suppressor PTEN. Recently, it has been suggested that tumors deficient for PTEN might depend on the function of another class I member, PI3Kβ, to sustain their transformed phenotype. Taken together, these findings provide a significant medical rationale to study the signaling cascades regulated by PI3Kα and PI3Kβ particularly in the context of their role in the development and maintenance of human cancer. Here, we summarize the current understanding of the upstream receptor regulation of the two PI3K isoforms and their roles in cancer as well as their functional requirements in downstream signaling cascades.
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Affiliation(s)
- Nina Ilić
- Department of Cancer Biology, Harvard Medical School, Boston, MA 02115, USA
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247
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Sacco E, Abraham SJ, Palmioli A, Damore G, Bargna A, Mazzoleni E, Gaponenko V, Vanoni M, Peri F. Binding properties and biological characterization of new sugar-derived Ras ligands. MEDCHEMCOMM 2011. [DOI: 10.1039/c0md00264j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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248
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Vilar JMG. Noisy-threshold control of cell death. BMC SYSTEMS BIOLOGY 2010; 4:152. [PMID: 21067567 PMCID: PMC2992511 DOI: 10.1186/1752-0509-4-152] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 11/10/2010] [Indexed: 01/17/2023]
Abstract
Background Cellular responses to death-promoting stimuli typically proceed through a differentiated multistage process, involving a lag phase, extensive death, and potential adaptation. Deregulation of this chain of events is at the root of many diseases. Improper adaptation is particularly important because it allows cell sub-populations to survive even in the continuous presence of death conditions, which results, among others, in the eventual failure of many targeted anticancer therapies. Results Here, I show that these typical responses arise naturally from the interplay of intracellular variability with a threshold-based control mechanism that detects cellular changes in addition to just the cellular state itself. Implementation of this mechanism in a quantitative model for T-cell apoptosis, a prototypical example of programmed cell death, captures with exceptional accuracy experimental observations for different expression levels of the oncogene Bcl-xL and directly links adaptation with noise in an ATP threshold below which cells die. Conclusions These results indicate that oncogenes like Bcl-xL, besides regulating absolute death values, can have a novel role as active controllers of cell-cell variability and the extent of adaptation.
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Affiliation(s)
- Jose M G Vilar
- Biophysics Unit, CSIC-UPV/EHU and Department of Biochemistry and Molecular Biology, University of the Basque Country, PO Box 644, 48080 Bilbao, Spain.
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249
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Shen MM, Abate-Shen C. Molecular genetics of prostate cancer: new prospects for old challenges. Genes Dev 2010; 24:1967-2000. [PMID: 20844012 DOI: 10.1101/gad.1965810] [Citation(s) in RCA: 693] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite much recent progress, prostate cancer continues to represent a major cause of cancer-related mortality and morbidity in men. Since early studies on the role of the androgen receptor that led to the advent of androgen deprivation therapy in the 1940s, there has long been intensive interest in the basic mechanisms underlying prostate cancer initiation and progression, as well as the potential to target these processes for therapeutic intervention. Here, we present an overview of major themes in prostate cancer research, focusing on current knowledge of principal events in cancer initiation and progression. We discuss recent advances, including new insights into the mechanisms of castration resistance, identification of stem cells and tumor-initiating cells, and development of mouse models for preclinical evaluation of novel therapuetics. Overall, we highlight the tremendous research progress made in recent years, and underscore the challenges that lie ahead.
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Affiliation(s)
- Michael M Shen
- Department of Medicine, Columbia University Medical Center, New York, New York 10032, USA.
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250
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Kuiken HJ, Beijersbergen RL. Exploration of synthetic lethal interactions as cancer drug targets. Future Oncol 2010; 6:1789-802. [DOI: 10.2217/fon.10.131] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In cancer research the quest continues to identify the Achilles’ heel of cancer. The ideal cancer drug targets are those that are essential in tumor cells but not in normal cells. Such targets are defined as cancer-specific vulnerabilities or as synthetic lethal interactions with cancer-specific genetic lesions. The search for synthetic lethal interactions focuses on proteins that are frequently mutated but elude pharmacological inhibition, for example, RAS, or proteins that are lost in cancer cells and by definition cannot be targeted, such as the tumor suppressor genes p53, APC and RB. These genetic interactions could yield alternative, effective targets for cancer treatment. However, it remains very difficult to predict or extrapolate these synthetic lethal interactions based on existing knowledge. With the discovery of RNAi, unbiased large-scale functional genomic screens for the identification of such targets have become possible potentially leading to major advances in the treatment of cancers. In this review we will discuss the biological basis of synthetic lethal interactions in relation to existing targeted therapeutics, lessons taught by targeted therapeutics already used in the clinic and the implementation of RNAi as tool to identify such synthetic lethal interactions.
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Affiliation(s)
- Hendrik J Kuiken
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Roderick L Beijersbergen
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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