Combined Inactivation of MYC and K-Ras Oncogenes Reverses Tumorigenesis in Lung Adenocarcinomas and Lymphomas

Background Conditional transgenic models have established that tumors require sustained oncogene activation for tumor maintenance, exhibiting the phenomenon known as “oncogene-addiction.” However, most cancers are caused by multiple genetic events making it difficult to determine which oncogenes or combination of oncogenes will be the most effective targets for their treatment. Methodology/Principal Findings To examine how the MYC and K-rasG12D oncogenes cooperate for the initiation and maintenance of tumorigenesis, we generated double conditional transgenic tumor models of lung adenocarcinoma and lymphoma. The ability of MYC and K-rasG12D to cooperate for tumorigenesis and the ability of the inactivation of these oncogenes to result in tumor regression depended upon the specific tissue context. MYC-, K-rasG12D- or MYC/K-rasG12D-induced lymphomas exhibited sustained regression upon the inactivation of either or both oncogenes. However, in marked contrast, MYC-induced lung tumors failed to regress completely upon oncogene inactivation; whereas K-rasG12D-induced lung tumors regressed completely. Importantly, the combined inactivation of both MYC and K-rasG12D resulted more frequently in complete lung tumor regression. To account for the different roles of MYC and K-rasG12D in maintenance of lung tumors, we found that the down-stream mediators of K-rasG12D signaling, Stat3 and Stat5, are dephosphorylated following conditional K-rasG12D but not MYC inactivation. In contrast, Stat3 becomes dephosphorylated in lymphoma cells upon inactivation of MYC and/or K-rasG12D. Interestingly, MYC-induced lung tumors that failed to regress upon MYC inactivation were found to have persistent Stat3 and Stat5 phosphorylation. Conclusions/Significance Taken together, our findings point to the importance of the K-Ras and associated down-stream Stat effector pathways in the initiation and maintenance of lymphomas and lung tumors. We suggest that combined targeting of oncogenic pathways is more likely to be effective in the treatment of lung cancers and lymphomas.

[1]  B. Groner,et al.  Signal transducer and activator of transcription 5 (STAT5), a crucial regulator of immune and cancer cells. , 2005, Current drug targets. Immune, endocrine and metabolic disorders.

[2]  L. Chodosh,et al.  Isoform-Specific Ras Activation and Oncogene Dependence during MYC- and Wnt-Induced Mammary Tumorigenesis , 2006, Molecular and Cellular Biology.

[3]  Daniel A. Haber,et al.  Gefitinib-Sensitizing EGFR Mutations in Lung Cancer Activate Anti-Apoptotic Pathways , 2004, Science.

[4]  C. Shachaf,et al.  Conditional animal models: a strategy to define when oncogenes will be effective targets to treat cancer. , 2004, Seminars in cancer biology.

[5]  T. Jacks,et al.  Somatic activation of the K-ras oncogene causes early onset lung cancer in mice , 2001, Nature.

[6]  G. Bepler,et al.  Activated Epidermal Growth Factor Receptor–Stat-3 Signaling Promotes Tumor Survival In vivo in Non–Small Cell Lung Cancer , 2005, Clinical Cancer Research.

[7]  Levi A Garraway,et al.  Mutations in BRAF and KRAS converge on activation of the mitogen-activated protein kinase pathway in lung cancer mouse models. , 2007, Cancer research.

[8]  M. Meyerson,et al.  Bronchial and peripheral murine lung carcinomas induced by T790M-L858R mutant EGFR respond to HKI-272 and rapamycin combination therapy. , 2007, Cancer cell.

[9]  H. Sasaki,et al.  EGFR and erbB2 mutation status in Japanese lung cancer patients , 2006, International journal of cancer.

[10]  A. Joe,et al.  Mechanisms of Disease: oncogene addiction—a rationale for molecular targeting in cancer therapy , 2006, Nature Clinical Practice Oncology.

[11]  P. Jänne,et al.  The impact of human EGFR kinase domain mutations on lung tumorigenesis and in vivo sensitivity to EGFR-targeted therapies. , 2006, Cancer cell.

[12]  W. Pao,et al.  Update on Epidermal Growth Factor Receptor Mutations in Non–Small Cell Lung Cancer , 2006, Clinical Cancer Research.

[13]  D. Felsher,et al.  Getting at MYC through RAS , 2005, Clinical Cancer Research.

[14]  K. Lim,et al.  Reduction in the requirement of oncogenic Ras signaling to activation of PI3K/AKT pathway during tumor maintenance. , 2005, Cancer cell.

[15]  Guido Gerig,et al.  User-guided 3D active contour segmentation of anatomical structures: Significantly improved efficiency and reliability , 2006, NeuroImage.

[16]  M. Fischbach,et al.  “Oncogenic Shock”: Explaining Oncogene Addiction through Differential Signal Attenuation , 2006, Clinical Cancer Research.

[17]  J. Minna,et al.  Somatic mutations of the HER2 kinase domain in lung adenocarcinomas. , 2005, Cancer research.

[18]  Robert D Cardiff,et al.  Impact of p53 loss on reversal and recurrence of conditional Wnt-induced tumorigenesis. , 2003, Genes & development.

[19]  Joseph R. Nevins,et al.  A signalling pathway controlling c-Myc degradation that impacts oncogenic transformation of human cells , 2004, Nature Cell Biology.

[20]  W. Hahn,et al.  Modelling the molecular circuitry of cancer , 2002, Nature Reviews Cancer.

[21]  M. Kris,et al.  Molecular on/off switch. , 2006, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[22]  D. Haber,et al.  A common signaling cascade may underlie "addiction" to the Src, BCR-ABL, and EGF receptor oncogenes. , 2006, Cancer cell.

[23]  J. Sambrook,et al.  Molecular cloning–A laboratory manual. New York: Cold Spring Harbor Laboratory. 1982, 545 S., 42 $ , 1985 .

[24]  C. Cordon-Cardo,et al.  Hyperactivation of Ha-ras oncogene, but not Ink4a/Arf deficiency, triggers bladder tumorigenesis. , 2007, The Journal of clinical investigation.

[25]  H. Varmus,et al.  Lung adenocarcinomas induced in mice by mutant EGF receptors found in human lung cancers respond to a tyrosine kinase inhibitor or to down-regulation of the receptors. , 2006, Genes & development.

[26]  L. Chin,et al.  Essential role for oncogenic Ras in tumour maintenance , 1999, Nature.

[27]  R. Cardiff,et al.  Classification of Proliferative Pulmonary Lesions of the Mouse , 2004, Cancer Research.

[28]  Christopher H. Contag,et al.  MYC inactivation uncovers pluripotent differentiation and tumour dormancy in hepatocellular cancer , 2004, Nature.

[29]  Francisco Cervantes,et al.  Five-year follow-up of patients receiving imatinib for chronic myeloid leukemia. , 2006, The New England journal of medicine.

[30]  Andrew D. Yates,et al.  Athletics: Momentous sprint at the 2156 Olympics? , 2004, Nature.

[31]  C. Der,et al.  Distinct requirements for Ras oncogenesis in human versus mouse cells. , 2002, Genes & development.

[32]  Mitchell D Schnall,et al.  Conditional activation of Neu in the mammary epithelium of transgenic mice results in reversible pulmonary metastasis. , 2002, Cancer cell.

[33]  M. Greaves.  Differentiation-linked leukemogenesis in lymphocytes. , 1986, Science.

[34]  Kenneth Chu,et al.  Sustained Loss of a Neoplastic Phenotype by Brief Inactivation of MYC , 2002, Science.

[35]  Jeffrey A. Whitsett,et al.  Conditional gene expression in the respiratory epithelium of the mouse , 2002, Transgenic Research.

[36]  Kathryn A. O’Donnell,et al.  The c-Myc target gene network. , 2006, Seminars in cancer biology.

[37]  Richard Wooster,et al.  BRAF and RAS mutations in human lung cancer and melanoma. , 2002, Cancer research.

[38]  Hua Yu,et al.  The STATs of cancer — new molecular targets come of age , 2004, Nature Reviews Cancer.

[39]  C. Arvanitis,et al.  Conditional transgenic models define how MYC initiates and maintains tumorigenesis. , 2006, Seminars in cancer biology.

[40]  Channing J Der,et al.  Renewing the conspiracy theory debate: does Raf function alone to mediate Ras oncogenesis? , 2004, Trends in cell biology.

[41]  I. Weinstein.  Addiction to Oncogenes--the Achilles Heal of Cancer , 2002, Science.

[42]  D. Felsher,et al.  Reversible tumorigenesis by MYC in hematopoietic lineages. , 1999, Molecular cell.

[43]  W. Kaelin.  The Concept of Synthetic Lethality in the Context of Anticancer Therapy , 2005, Nature Reviews Cancer.

[44]  H. Sasaki,et al.  Uncommon V599E BRAF mutations in Japanese patients with lung cancer. , 2006, The Journal of surgical research.

[45]  H. Varmus,et al.  Induction and apoptotic regression of lung adenocarcinomas by regulation of a K-Ras transgene in the presence and absence of tumor suppressor genes. , 2001, Genes & development.

[46]  M. Meyerson,et al.  Missense mutations of the BRAF gene in human lung adenocarcinoma. , 2002, Cancer research.

[47]  G. Evan,et al.  Reversible activation of c-Myc in skin: induction of a complex neoplastic phenotype by a single oncogenic lesion. , 1999, Molecular cell.

[48]  R. Wilson,et al.  Mutational Analysis of EGFR and Related Signaling Pathway Genes in Lung Adenocarcinomas Identifies a Novel Somatic Kinase Domain Mutation in FGFR4 , 2007, PloS one.

[49]  A. D. Van den Abbeele,et al.  Kinase mutations and imatinib response in patients with metastatic gastrointestinal stromal tumor. , 2003, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[50]  G. Evan,et al.  Suppression of Myc-Induced Apoptosis in β Cells Exposes Multiple Oncogenic Properties of Myc and Triggers Carcinogenic Progression , 2002, Cell.

[51]  W. Gerald,et al.  Mutations in the EGFR kinase domain mediate STAT3 activation via IL-6 production in human lung adenocarcinomas. , 2007, The Journal of clinical investigation.

[52]  C. Sawyers,et al.  Activity of a specific inhibitor of the BCR-ABL tyrosine kinase in the blast crisis of chronic myeloid leukemia and acute lymphoblastic leukemia with the Philadelphia chromosome. , 2001, The New England journal of medicine.

[53]  Suzanne Schubbert,et al.  Hyperactive Ras in developmental disorders and cancer , 2007, Nature Reviews Cancer.

[54]  Joon-Oh Park,et al.  MET Amplification Leads to Gefitinib Resistance in Lung Cancer by Activating ERBB3 Signaling , 2007, Science.

[55]  Keith L. Ligon,et al.  Coactivation of Receptor Tyrosine Kinases Affects the Response of Tumor Cells to Targeted Therapies , 2007, Science.

[56]  R. Cardiff,et al.  c-MYC induces mammary tumorigenesis by means of a preferred pathway involving spontaneous Kras2 mutations , 2001, Nature Medicine.

[57]  C. A. Thomas,et al.  Molecular cloning. , 1977, Advances in pathobiology.

[58]  M. Meyerson,et al.  Epidermal growth factor receptor variant III mutations in lung tumorigenesis and sensitivity to tyrosine kinase inhibitors , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[59]  M. Meyerson,et al.  Signal transducer and activator of transcription 3 is required for the oncogenic effects of non-small-cell lung cancer-associated mutations of the epidermal growth factor receptor. , 2006, Cancer research.

[60]  P. Leder,et al.  Coexpression of MMTV/v-Ha-ras and MMTV/c-myc genes in transgenic mice: Synergistic action of oncogenes in vivo , 1987, Cell.

[61]  W. Park,et al.  ERBB2 kinase domain mutation in the lung squamous cell carcinoma. , 2006, Cancer letters.

[62]  Andrew D. Yates,et al.  Somatic mutations of the protein kinase gene family in human lung cancer. , 2005, Cancer research.

[63]  Robert B Boxer,et al.  Lack of sustained regression of c-MYC-induced mammary adenocarcinomas following brief or prolonged MYC inactivation. , 2004, Cancer cell.

[64]  C. Sawyers,et al.  Targeted cancer therapy , 2004, Nature.

[65]  C. Arteaga.  HER3 and mutant EGFR meet MET , 2007, Nature Medicine.

[66]  P. Leder,et al.  Consequences of widespread deregulation of the c-myc gene in transgenic mice: Multiple neoplasms and normal development , 1986, Cell.

[67]  Shishinn Sun,et al.  PTEN is a negative regulator of STAT3 activation in human papillomavirus-infected cells. , 2002, The Journal of general virology.