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1.
Int J Cancer ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-39001563

ABSTRACT

Despite advancements in treating cutaneous melanoma, patients with acral and mucosal (A/M) melanomas still have limited therapeutic options and poor prognoses. We analyzed 156 melanomas (101 cutaneous, 28 acral, and 27 mucosal) using the Foundation One cancer-gene specific clinical testing platform and identified new, potentially targetable genomic alterations (GAs) in specific anatomic sites of A/M melanomas. Using novel pre-clinical models of A/M melanoma, we demonstrate that several GAs and corresponding oncogenic pathways associated with cutaneous melanomas are similarly targetable in A/M melanomas. Other alterations, including MYC and CRKL amplifications, were unique to A/M melanomas and susceptible to indirect targeting using the BRD4 inhibitor JQ1 or Src/ABL inhibitor dasatinib, respectively. We further identified new, actionable A/M-specific alterations, including an inactivating NF2 fusion in a mucosal melanoma responsive to dasatinib in vivo. Our study highlights new molecular differences between cutaneous and A/M melanomas, and across different anatomic sites within A/M, which may change clinical testing and treatment paradigms for these rare melanomas.

2.
Sci Rep ; 10(1): 17536, 2020 10 16.
Article in English | MEDLINE | ID: mdl-33067482

ABSTRACT

Clinical trials establish the standard of cancer care, yet the evolution and characteristics of the social dynamics between the people conducting this work remain understudied. We performed a social network analysis of authors publishing chemotherapy-based prospective trials from 1946 to 2018 to understand how social influences, including the role of gender, have influenced the growth and development of this network, which has expanded exponentially from fewer than 50 authors in 1946 to 29,197 in 2018. While 99.4% of authors were directly or indirectly connected by 2018, our results indicate a tendency to predominantly connect with others in the same or similar fields, as well as an increasing disparity in author impact and number of connections. Scale-free effects were evident, with small numbers of individuals having disproportionate impact. Women were under-represented and likelier to have lower impact, shorter productive periods (P < 0.001 for both comparisons), less centrality, and a greater proportion of co-authors in their same subspecialty. The past 30 years were characterized by a trend towards increased authorship by women, with new author parity anticipated in 2032. The network of cancer clinical trialists is best characterized as strategic or mixed-motive, with cooperative and competitive elements influencing its appearance. Network effects such as low centrality, which may limit access to high-profile individuals, likely contribute to the observed disparities.


Subject(s)
Antineoplastic Agents/therapeutic use , Clinical Trials as Topic , Medical Oncology/history , Neoplasms/drug therapy , Publishing/trends , Social Network Analysis , Algorithms , Authorship , Female , History, 20th Century , History, 21st Century , Humans , Male , Prospective Studies , Randomized Controlled Trials as Topic , Research Design , Research Personnel
3.
Cancers (Basel) ; 12(8)2020 Aug 13.
Article in English | MEDLINE | ID: mdl-32823698

ABSTRACT

Glembatumumab vedotin (CDX-011, GV) is a fully human Immunoglobulin G2 monoclonal antibody directed against glycoprotein NMB coupled via a peptide linker to monomethyl auristatin E (MMAE), a potent cytotoxic microtubule inhibitor. This phase II study evaluated the overall response rate and safety of GV, glycoprotein NMB (GPNMB) expression, and survival in patients with metastatic uveal melanoma. Eligible patients with metastatic uveal melanoma who had not previously been treated with chemotherapy received GV 1.9 mg/kg every three weeks. The primary endpoint was the objective response rate (ORR). Secondary endpoints included GPNMB expression, progression-free survival (PFS), overall survival (OS), and toxicity analysis. GPNMB expression was assessed pre- and post-treatment via immunohistochemistry for patients with available tumor tissue. Out of 35 patients who received treatment, two patients had confirmed partial responses (PRs; 6%), and 18 patients had a stable disease (SD; 51%) as the best objective response. 38% of the patients had stable disease >100 days. The grade 3 or 4 toxicities that occurred in two or more patients were neutropenia, rash, hyponatremia, and vomiting. The median progression-free survival was 3.1 months (95% CI: 1.5-5.6), and the median overall survival was 11.9 months (95% CI 9.0-16.9) in the evaluable study population. GV is well-tolerated in metastatic uveal melanoma. The disease control rate was 57% despite a low objective response rate. Exploratory immune correlation studies are underway to provide insight into target saturation, combination strategies, and antigen release.

4.
Pharmacogenomics ; 21(6): 375-386, 2020 04.
Article in English | MEDLINE | ID: mdl-32077359

ABSTRACT

In recent years, the genomics community has witnessed the growth of large research biobanks, which collect DNA samples for research purposes. Depending on how and where the samples are genotyped, biobanks also offer the potential opportunity to return actionable genomic results to the clinical setting. We developed a preemptive clinical pharmacogenomic implementation initiative via a health system-wide research biobank at the University of Colorado. Here, we describe how preemptive return of clinical pharmacogenomic results via a research biobank is feasible, particularly when coupled with strong institutional support to maximize the impact and efficiency of biobank resources, a multidisciplinary implementation team, automated clinical decision support tools, and proactive strategies to engage stakeholders early in the clinical decision support tool development process.


Subject(s)
Academic Medical Centers/trends , Biological Specimen Banks/trends , Decision Support Systems, Clinical/trends , Pharmacogenetics/trends , Precision Medicine/trends , Academic Medical Centers/methods , Colorado/epidemiology , Cytochrome P-450 CYP2C19/genetics , Humans , Pharmacogenetics/methods , Precision Medicine/methods
5.
J Surg Oncol ; 120(7): 1276-1283, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31602665

ABSTRACT

OBJECTIVE: To develop a nomogram to estimate the probability of positive sentinel lymph node (+SLN) for patients with thin melanoma and to characterize its potential impact on sentinel lymph node biopsy (SLNB) rates. METHODS: Patients diagnosed with thin (0.5-1.0 mm) melanoma were identified from the National Cancer Database 2012 to 2015. A multivariable logistic regression model was used to examine factors associated with +SLN, and a nomogram to predict +SLN was constructed. Nomogram performance was evaluated and diagnostic test statistics were calculated. RESULTS: Of the 21 971 patients included 10 108 (46.0%) underwent SLNB, with a 4.0% +SLN rate. On multivariable analysis, age, Breslow thickness, lymphovascular invasion, ulceration, and Clark level were significantly associated with SLN status. The area under the receiver operating curve was 0.67 (95% confidence interval, 0.65-0.70). While 15 249 (69.4%) patients had either T1b tumors or T1a tumors with at least one adverse feature, only 2846 (13.0%) had a nomogram predicted probability of a +SLN ≥5%. Using this cut-off, the indication for a SLNB in these patients would be reduced by 81.3% as compared to the American Joint Committee on Cancer 8th edition staging criteria. CONCLUSIONS: The risk predictions obtained from the nomogram allow for more accurate selection of patients who could benefit from SLNB.


Subject(s)
Decision Making , Melanoma/pathology , Nomograms , Risk Assessment/methods , Sentinel Lymph Node/pathology , Skin Neoplasms/pathology , Aged , Databases, Factual , Female , Follow-Up Studies , Humans , Male , Melanoma/surgery , Middle Aged , Neoplasm Staging , Retrospective Studies , Sentinel Lymph Node/surgery , Sentinel Lymph Node Biopsy , Skin Neoplasms/surgery
6.
J Am Acad Dermatol ; 80(6): 1640-1649, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30654077

ABSTRACT

BACKGROUND: Clinical guidelines for the treatment of melanoma are based largely on the behavior of thicker tumors. As a result, little is known about survival differences among patients with thinner tumors. OBJECTIVE: To investigate the variability in survival for American Joint Committee on Cancer stage T1 thin melanoma tumors, defined as tumors less than 1 mm thick at diagnosis. METHODS: This population-based series included 43,008 non-Hispanic whites in whom cutaneous melanoma was diagnosed between 2004 and 2013 from the California Cancer Registry. Survival outcomes were estimated using the Kaplan-Meier method. Cox proportional hazard models were used to estimate risk of death. RESULTS: Survival for patients with thin ulcerated tumors was comparable to that for patients with stage II tumors, who are currently treated more aggressively. At 12 months, patients with thin ulcerated tumors had approximately 6% lower survival (92.5% [95% confidence interval (CI), 90.6%-93.9%]) compared with patients with thin nonulcerated tumors (98.2% [95% CI, 98.0%-98.3%]). At 24 months, this survival difference increased (85.2% [95% CI, 82.8%-87.4%] vs 96.1% [95% CI, 95.8-96.3%] for those with thin ulcerated and thin nonulcerated tumors, respectively) and a greater than 15% survival difference was seen at 60 months. LIMITATIONS: Previous reports of cancer registry data have noted some evidence of miscoding of thin tumors. CONCLUSION: The poorer survival in patients with ulcerated tumors less than 1 mm thick implies the need for additional studies to determine potential benefits of more aggressive treatment.


Subject(s)
Melanoma/complications , Skin Neoplasms/complications , Skin Ulcer/etiology , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , California/epidemiology , Child , Combined Modality Therapy , Female , Humans , Immunotherapy , Kaplan-Meier Estimate , Male , Melanoma/mortality , Melanoma/pathology , Melanoma/therapy , Middle Aged , Neoplasm Invasiveness , Neoplasm Staging , Prognosis , Proportional Hazards Models , Registries , Skin Neoplasms/mortality , Skin Neoplasms/pathology , Skin Neoplasms/therapy , Socioeconomic Factors , Melanoma, Cutaneous Malignant
7.
Mol Cancer Ther ; 17(1): 222-231, 2018 01.
Article in English | MEDLINE | ID: mdl-29054983

ABSTRACT

Oncogenic ALK fusions occur in several types of cancer and can be effectively treated with ALK inhibitors; however, ALK fusions and treatment response have not been characterized in malignant melanomas. Recently, a novel isoform of ALK (ALKATI ) was reported in 11% of melanomas but the response of melanomas expressing ALKATI to ALK inhibition has not been well characterized. We analyzed 45 melanoma patient-derived xenograft models for ALK mRNA and protein expression. ALK expression was identified in 11 of 45 (24.4%) melanomas. Ten melanomas express wild-type (wt) ALK and/or ALKATI and one mucosal melanoma expresses multiple novel EML4-ALK fusion variants. Melanoma cells expressing different ALK variants were tested for response to ALK inhibitors. Whereas the melanoma expressing EML4-ALK were sensitive to ALK inhibitors in vitro and in vivo, the melanomas expressing wt ALK or ALKATI were not sensitive to ALK inhibitors. In addition, a patient with mucosal melanoma expressing ALKATI was treated with an ALK/ROS1/TRK inhibitor (entrectinib) on a phase I trial but did not respond. Our results demonstrate ALK fusions occur in malignant melanomas and respond to targeted therapy, whereas melanomas expressing ALKATI do not respond to ALK inhibitors. Targeting ALK fusions is an effective therapeutic option for a subset of melanoma patients, but additional clinical studies are needed to determine the efficacy of targeted therapies in melanomas expressing wt ALK or ALKATIMol Cancer Ther; 17(1); 222-31. ©2017 AACR.


Subject(s)
Melanoma/genetics , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Animals , Female , Humans , Melanoma/pathology , Mice , Mice, Nude , Middle Aged , Protein Isoforms , Xenograft Model Antitumor Assays
8.
Cancer Immunol Res ; 4(11): 959-967, 2016 11.
Article in English | MEDLINE | ID: mdl-27671167

ABSTRACT

Therapeutic antibodies blocking programmed death-1 and its ligand (PD-1/PD-L1) induce durable responses in a substantial fraction of melanoma patients. We sought to determine whether the number and/or type of mutations identified using a next-generation sequencing (NGS) panel available in the clinic was correlated with response to anti-PD-1 in melanoma. Using archival melanoma samples from anti-PD-1/PD-L1-treated patients, we performed hybrid capture-based NGS on 236-315 genes and T-cell receptor (TCR) sequencing on initial and validation cohorts from two centers. Patients who responded to anti-PD-1/PD-L1 had higher mutational loads in an initial cohort (median, 45.6 vs. 3.9 mutations/MB; P = 0.003) and a validation cohort (37.1 vs. 12.8 mutations/MB; P = 0.002) compared with nonresponders. Response rate, progression-free survival, and overall survival were superior in the high, compared with intermediate and low, mutation load groups. Melanomas with NF1 mutations harbored high mutational loads (median, 62.7 mutations/MB) and high response rates (74%), whereas BRAF/NRAS/NF1 wild-type melanomas had a lower mutational load. In these archival samples, TCR clonality did not predict response. Mutation numbers in the 315 genes in the NGS platform strongly correlated with those detected by whole-exome sequencing in The Cancer Genome Atlas samples, but was not associated with survival. In conclusion, mutational load, as determined by an NGS platform available in the clinic, effectively stratified patients by likelihood of response. This approach may provide a clinically feasible predictor of response to anti-PD-1/PD-L1. Cancer Immunol Res; 4(11); 959-67. ©2016 AACR.


Subject(s)
Antineoplastic Agents, Immunological/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , High-Throughput Nucleotide Sequencing , Neoplasms/genetics , Programmed Cell Death 1 Receptor/antagonists & inhibitors , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism , Adult , Aged , Aged, 80 and over , Antineoplastic Agents, Immunological/therapeutic use , B7-H1 Antigen/antagonists & inhibitors , Biomarkers, Tumor , DNA Mutational Analysis , Female , Gene Expression Profiling , Humans , Middle Aged , Mutation , Neoplasm Metastasis , Neoplasm Staging , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/mortality , Prognosis , Transcriptome
9.
J Am Med Inform Assoc ; 23(4): 773-6, 2016 07.
Article in English | MEDLINE | ID: mdl-27026612

ABSTRACT

BACKGROUND: Precision oncology increasingly utilizes molecular profiling of tumors to determine treatment decisions with targeted therapeutics. The molecular profiling data is valuable in the treatment of individual patients as well as for multiple secondary uses. OBJECTIVE: To automatically parse, categorize, and aggregate clinical molecular profile data generated during cancer care as well as use this data to address multiple secondary use cases. METHODS: A system to parse, categorize and aggregate molecular profile data was created. A naÿve Bayesian classifier categorized results according to clinical groups. The accuracy of these systems were validated against a published expertly-curated subset of molecular profiling data. RESULTS: Following one year of operation, 819 samples have been accurately parsed and categorized to generate a data repository of 10,620 genetic variants. The database has been used for operational, clinical trial, and discovery science research. CONCLUSIONS: A real-time database of molecular profiling data is a pragmatic solution to several knowledge management problems in the practice and science of precision oncology.


Subject(s)
Databases, Genetic , Gene Expression Profiling , Neoplasms/genetics , Precision Medicine , Humans , Medical Oncology
10.
J Am Med Inform Assoc ; 23(4): 701-10, 2016 07.
Article in English | MEDLINE | ID: mdl-27018265

ABSTRACT

BACKGROUND: Precision cancer medicine (PCM) will require ready access to genomic data within the clinical workflow and tools to assist clinical interpretation and enable decisions. Since most electronic health record (EHR) systems do not yet provide such functionality, we developed an EHR-agnostic, clinico-genomic mobile app to demonstrate several features that will be needed for point-of-care conversations. METHODS: Our prototype, called Substitutable Medical Applications and Reusable Technology (SMART)® PCM, visualizes genomic information in real time, comparing a patient's diagnosis-specific somatic gene mutations detected by PCR-based hotspot testing to a population-level set of comparable data. The initial prototype works for patient specimens with 0 or 1 detected mutation. Genomics extensions were created for the Health Level Seven® Fast Healthcare Interoperability Resources (FHIR)® standard; otherwise, the prototype is a normal SMART on FHIR app. RESULTS: The PCM prototype can rapidly present a visualization that compares a patient's somatic genomic alterations against a distribution built from more than 3000 patients, along with context-specific links to external knowledge bases. Initial evaluation by oncologists provided important feedback about the prototype's strengths and weaknesses. We added several requested enhancements and successfully demonstrated the app at the inaugural American Society of Clinical Oncology Interoperability Demonstration; we have also begun to expand visualization capabilities to include cancer specimens with multiple mutations. DISCUSSION: PCM is open-source software for clinicians to present the individual patient within the population-level spectrum of cancer somatic mutations. The app can be implemented on any SMART on FHIR-enabled EHRs, and future versions of PCM should be able to evolve in parallel with external knowledge bases.


Subject(s)
Mobile Applications , Neoplasms/genetics , Point-of-Care Systems , Precision Medicine , DNA, Neoplasm , Electronic Health Records , Genome , Health Information Interoperability , Health Level Seven , Humans , Mutation , User-Computer Interface
11.
J Oncol Pract ; 12(3): e332-7, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26813927

ABSTRACT

Oncology practice increasingly requires the use of molecular profiling of tumors to inform the use of targeted therapeutics. However, many oncologists use third-party laboratories to perform tumor genomic testing, and these laboratories may not have electronic interfaces with the provider's electronic medical record (EMR) system. The resultant reporting mechanisms, such as plain-paper faxing, can reduce report fidelity, slow down reporting procedures for a physician's practice, and make reports less accessible. Vanderbilt University Medical Center and its genomic laboratory testing partner have collaborated to create an automated electronic reporting system that incorporates genetic testing results directly into the clinical EMR. This system was iteratively tested, and causes of failure were discovered and addressed. Most errors were attributable to data entry or typographical errors that made reports unable to be linked to the correct patient in the EMR. By providing direct feedback to providers, we were able to significantly decrease the rate of transmission errors (from 6.29% to 3.84%; P < .001). The results and lessons of 1 year of using the system and transmitting 832 tumor genomic testing reports are reported.


Subject(s)
Electronic Health Records/standards , Neoplasms/diagnosis , Humans , Molecular Diagnostic Techniques , Neoplasms/genetics , Quality Improvement
12.
Article in English | MEDLINE | ID: mdl-25993230

ABSTRACT

The World Wide Web, which has been widely implemented for roughly two decades, is humankind's most impressive effort to aggregate and organize knowledge to date. The medical community was slower to embrace the Internet than others, but the majority of clinicians now use it as part of their everyday practice. For the practicing oncologist, there is a daunting quantity of information to master. For example, a new article relating to cancer is added to the MEDLINE database approximately every 3 minutes. Fortunately, Internet resources can help organize the deluge of information into useful knowledge. This manuscript provides an overview of resources related to general medicine, oncology, and social media that will be of practical use to the practicing oncologist. It is clear from the vast size of the Internet that we are all life-long learners, and the challenge is to acquire "just-in-time" information so that we can provide the best possible care to our patients. The resources that we have presented in this article should help the practicing oncologist continue along the path of transforming information to knowledge to wisdom.


Subject(s)
Internet , Practice Patterns, Physicians' , Humans , Social Media , Web Browser
13.
Curr Treat Options Oncol ; 15(4): 658-69, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25096781

ABSTRACT

OPINION STATEMENT: Lung cancer is the leading cause of cancer-related mortality worldwide. Cytotoxic chemotherapy and tyrosine kinase inhibitors provide palliation and prolong survival, however, the median survival for patients with metastatic disease remains poor and more effective therapies are needed. Immune checkpoint inhibitors have shown promising results in phase I trials and are being evaluated in ongoing clinical trials in both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) patients. These include agents targeting the programmed cell death-1 receptor and its ligand (PD-1/PD-L1; notably nivolumab, pembrolizumab, MPDL3280A, and MEDI-4736) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4; ipilimumab and tremelimumab); these agents induce antitumor responses by inhibiting critical negative T cell regulators. In particular, the anti-PD-1/PD-L1 therapies administered as single agent therapy in chemotherapy refractory patients have produced objective response rates ranging from 15 %-25 %, the majority of which were rapid and ongoing 1 year after starting therapy. Furthermore, the toxicity profile for these agents differs from that of cytotoxic chemotherapy but generally is much better tolerated. Promising biomarkers, particularly tumor expression of PD-L1 and tumor infiltrating lymphocytes, may aid in treatment selection and stratification. Ongoing evaluation is needed to define the most appropriate timing and patient population that will benefit from therapy with an immune checkpoint inhibitors and the role of combining these agents with existing therapies including systemic therapy and radiation.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Immunologic Factors/therapeutic use , Lung Neoplasms/drug therapy , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/immunology , Carcinoma, Non-Small-Cell Lung/metabolism , Humans , Immunologic Factors/pharmacology , Immunomodulation/drug effects , Lung Neoplasms/immunology , Lung Neoplasms/metabolism , Molecular Targeted Therapy
14.
Cancer Cell ; 13(5): 420-31, 2008 May.
Article in English | MEDLINE | ID: mdl-18455125

ABSTRACT

The NF-AT transcription factors regulated by the phosphatase calcineurin play a role in breast cancer metastasis-promoting tumor cell invasion. Metastasis is a multistep process requiring angiogenesis and endothelial activation. NF-AT is also expressed in endothelial cells, and calcineurin-NF-AT signaling is an important downstream effector of the proangiogenic cytokine VEGF. One isoform of the endogenous calcineurin regulator, Down syndrome candidate region-1 (DSCR1.Ex4), suppresses calcineurin-NFAT signaling blocking endothelial proliferation. However, overexpression of the other DSCR1 isoform (DSCR1.Ex1) may promote angiogenesis. We report that targeted deletion of both isoforms leads to hyperactivated calcineurin and precocious endothelial apoptosis, inhibiting formation of an effective tumor vasculature and suppressing tumorigenesis. Treatment with the specific pharmacological calcineurin inhibitor cyclosporin A rescues this endothelial defect in DSCR1(-/-) mice, restoring tumor growth.


Subject(s)
Colonic Neoplasms/blood supply , Colonic Neoplasms/pathology , Gene Deletion , Intracellular Signaling Peptides and Proteins/deficiency , Kidney Neoplasms/blood supply , Kidney Neoplasms/pathology , Muscle Proteins/deficiency , Animals , Calcineurin/physiology , Calcineurin Inhibitors , Calcium-Binding Proteins , Cell Division/genetics , Colonic Neoplasms/genetics , Endothelium, Vascular/pathology , Intracellular Signaling Peptides and Proteins/genetics , Kidney Neoplasms/genetics , Kinetics , Mice , Muscle Proteins/genetics , Mutation , Necrosis , Neovascularization, Pathologic/genetics
15.
Curr Biol ; 18(1): 56-62, 2008 Jan 08.
Article in English | MEDLINE | ID: mdl-18164202

ABSTRACT

Inactivating mutations in NF1 underlie the prevalent familial cancer syndrome neurofibromatosis type 1 [1]. The NF1-encoded protein is a Ras GTPase-activating protein (RasGAP) [2]. Accordingly, Ras is aberrantly activated in NF1-deficient tumors; however, it is unknown which effector pathways critically function in tumor development. Here we provide in vivo evidence that TORC1/mTOR activity is essential for tumorigenesis. Specifically, we show that the mTOR inhibitor rapamycin potently suppresses the growth of aggressive NF1-associated malignancies in a genetically engineered murine model. However, in these tumors rapamycin does not function via mechanisms generally assumed to mediate tumor suppression, including inhibition of HIF-1alpha and indirect suppression of AKT, but does suppress the mTOR target Cyclin D1 [3]. These results demonstrate that mTOR inhibitors may be an effective targeted therapy for this commonly untreatable malignancy. Moreover, they indicate that mTOR inhibitors do not suppress all tumor types via the same mechanism, suggesting that current biomarkers that rely on HIF-1alpha suppression may not be informative for all cancers. Finally, our results reveal important differences between the effects of mTOR inhibition on the microvasculature in genetically engineered versus xenograft models and indicate that the former may be required for effective preclinical screening with this class of inhibitors.


Subject(s)
Genes, Neurofibromatosis 1 , Neoplasms/genetics , Transcription Factors/physiology , Animals , Cell Line , Cyclin D , Cyclins/genetics , Cyclins/metabolism , Disease Models, Animal , Gene Expression Regulation/drug effects , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neoplasms/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Sirolimus/pharmacology , TOR Serine-Threonine Kinases , Transcription Factors/metabolism
16.
Proc Natl Acad Sci U S A ; 103(44): 16266-71, 2006 Oct 31.
Article in English | MEDLINE | ID: mdl-17056717

ABSTRACT

The targeted inactivation of oncogenes offers a rational therapeutic approach for the treatment of cancer. However, the therapeutic inactivation of a single oncogene has been associated with tumor recurrence. Therefore, it is necessary to develop strategies to override mechanisms of tumor escape from oncogene dependence. We report here that the targeted inactivation of MYC is sufficient to induce sustained regression of hematopoietic tumors in transgenic mice, except in tumors that had lost p53 function. p53 negative tumors were unable to be completely eliminated, as demonstrated by the kinetics of tumor cell elimination revealed by bioluminescence imaging. Histological examination revealed that upon MYC inactivation, the loss of p53 led to a deficiency in thrombospondin-1 (TSP-1) expression, a potent antiangiogenic protein, and the subsequent inability to shut off angiogenesis. Restoration of p53 expression in these tumors re-established TSP-1 expression. This permitted the suppression of angiogenesis and subsequent sustained tumor regression upon MYC inactivation. Similarly, the restoration of TSP-1 alone in p53 negative tumors resulted in the shut down of angiogenesis and led to sustained tumor regression upon MYC inactivation. Hence, the complete regression of tumor mass driven by inactivation of the MYC oncogene requires the p53-dependent induction of TSP-1 and the shut down of angiogenesis. Notably, overexpression of TSP-1 alone did not influence tumor growth. Therefore, the combined inactivation of oncogenes and angiogenesis may be a more clinically effective treatment of cancer. We conclude that angiogenesis is an essential component of oncogene addiction.


Subject(s)
Neoplasms/metabolism , Neoplasms/pathology , Proto-Oncogene Proteins c-myc/metabolism , Thrombospondin 1/metabolism , Tumor Suppressor Protein p53/metabolism , Animals , Cell Line, Tumor , Mice , Neoplasms/blood supply , Neoplasms/genetics , Proto-Oncogene Proteins c-myc/genetics , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics
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