Targeted expression of oncogenic K-ras in intestinal epithelium causes spontaneous tumorigenesis in mice.

BACKGROUND & AIMS Ras oncoproteins are mutated in about 50% of human colorectal cancers, but their precise role in tumor initiation or progression is still unclear. METHODS This study presents transgenic mice that express K-ras(V12G), the most frequent oncogenic mutation in human tumors, under control of the murine villin promoter in epithelial cells of the large and small intestine. RESULTS More than 80% of the transgenic animals displayed single or multiple intestinal lesions, ranging from aberrant crypt foci (ACF) to invasive adenocarcinomas. Expression of K-ras(V12G) caused activation of the MAP kinase cascade, and the tumors were frequently characterized by deregulated cellular proliferation. Unexpectedly, we obtained no evidence of inactivating mutations of the tumor suppressor gene Apc, the "gatekeeper" in colonic epithelial proliferation. However, spontaneous mutation of the tumor-suppressor gene p53, a frequent feature in the human disease, was found in 3 of 7 tumors that were tested. CONCLUSIONS This animal model recapitulates the stages of tumor progression as well as a part of the genetic alterations found in human colorectal cancer. Furthermore, it indicates that activation of K-ras in concert with mutations in p53 may constitute a route to digestive tumor formation and growth, underlining the fact that the pathway to intestinal cancer is not necessarily a single road.

[1]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.

[2]  H. Towbin,et al.  Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. , 1979, Proceedings of the National Academy of Sciences of the United States of America.

[3]  Cori Bargmann,et al.  Human colon carcinoma Ki-ras2 oncogene and its corresponding proto-oncogene , 1984, Molecular and cellular biology.

[4]  D. Louvard,et al.  Changes in villin synthesis and subcellular distribution during intestinal differentiation of HT29-18 clones , 1987, The Journal of cell biology.

[5]  B. Vogelstein,et al.  Prevalence of ras gene mutations in human colorectal cancers , 1987, Nature.

[6]  William E. Grizzle,et al.  Detection of high incidence of K-ras oncogenes during human colon tumorigenesis , 1987, Nature.

[7]  B. Vogelstein,et al.  A genetic model for colorectal tumorigenesis , 1990, Cell.

[8]  T. P. Pretlow,et al.  Aberrant crypts: putative preneoplastic foci in human colonic mucosa. , 1991, Cancer research.

[9]  D. Louvard,et al.  Developmental regulation of villin gene expression in the epithelial cell lineages of mouse digestive and urogenital tracts. , 1992, Development.

[10]  K. Kinzler,et al.  Erratum: Multiple Intestinal Neoplasia Caused By a Mutation in the Murine Homolog of the APC Gene , 1992, Science.

[11]  Bert Vogelstein,et al.  APC mutations occur early during colorectal tumorigenesis , 1992, Nature.

[12]  S H Kim,et al.  Transgenic mouse models that explore the multistep hypothesis of intestinal neoplasia , 1993, The Journal of cell biology.

[13]  K. Kinzler,et al.  Molecular determinants of dysplasia in colorectal lesions. , 1994, Cancer research.

[14]  Riccardo Fodde,et al.  Mutation detection by denaturing gradient gel electrophoresis (DGGE) , 1994, Human mutation.

[15]  R Fodde,et al.  A targeted chain-termination mutation in the mouse Apc gene results in multiple intestinal tumors. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[16]  J. Declue,et al.  Schwann cells from neurofibromin deficient mice exhibit activation of p21ras, inhibition of cell proliferation and morphological changes. , 1995, Oncogene.

[17]  Clarke Ar,et al.  Interaction between murine germline mutations in p53 and APC predisposes to pancreatic neoplasia but not to increased intestinal malignancy. , 1995 .

[18]  M Oshima,et al.  Loss of Apc heterozygosity and abnormal tissue building in nascent intestinal polyps in mice carrying a truncated Apc gene. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[19]  P. Chappuis,et al.  A simple p53 functional assay for screening cell lines, blood, and tumors. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[20]  H. Esumi,et al.  Frequent and characteristic K‐ras activation in aberrant crypt foci of colon. Is there preference among K‐ras mutants for malignant progression? , 1995, Cancer.

[21]  M. Radman,et al.  Inactivation of the mouse Msh2 gene results in mismatch repair deficiency, methylation tolerance, hyperrecombination, and predisposition to cancer , 1995, Cell.

[22]  T. Smyrk,et al.  Attenuated familial adenomatous polyposis (AFAP) a phenotypically and genotypically distinctive variant of FAP , 1995, Cancer.

[23]  D. Louvard,et al.  Suppression of villin expression by antisense RNA impairs brush border assembly in polarized epithelial intestinal cells. , 1995, The EMBO journal.

[24]  M. Cummings,et al.  Interaction between murine germline mutations in p53 and APC predisposes to pancreatic neoplasia but not to increased intestinal malignancy. , 1995, Oncogene.

[25]  Colorectal cancer genetics. Closing the gap between genotype and phenotype , 1995, Cancer.

[26]  A. Ochiai,et al.  Alteration of beta-catenin expression in colonic epithelial cells of familial adenomatous polyposis patients. , 1996, Cancer research.

[27]  Asad Umar,et al.  Meiotic Pachytene Arrest in MLH1-Deficient Mice , 1996, Cell.

[28]  K. Kinzler,et al.  Lessons from Hereditary Colorectal Cancer , 1996, Cell.

[29]  猪股雅史.  Alteration of β-catenin expression in colonic epithelial cells of familial adenomatous polyposis patients(家族性大腸腺腫症患者の大腸上皮細胞における細胞間接着分子β-カテニンの発現変化) , 1997 .

[30]  S. Shimizu,et al.  Mutations of the Ki‐ras, p53 and APC genes in adenocarcinomas of the human small intestine , 1997, International journal of cancer.

[31]  F. Jaisser,et al.  Epithelial cell growth and differentiation. IV. Controlled spatiotemporal expression of transgenes: new tools to study normal and pathological states. , 1997, The American journal of physiology.

[32]  Jeffrey I. Gordon,et al.  Bi-transgenic Mice Reveal that K-rasVal12 Augments a p53-independent Apoptosis When Small Intestinal Villus Enterocytes Reenter the Cell Cycle , 1997, The Journal of cell biology.

[33]  R. Kucherlapati,et al.  Loss of Apc and the entire chromosome 18 but absence of mutations at the Ras and Tp53 genes in intestinal tumors from Apc1638N, a mouse model for Apc-driven carcinogenesis. , 1997, Carcinogenesis.

[34]  T. Pawson,et al.  Aberrant Ras regulation and reduced p190 tyrosine phosphorylation in cells lacking p120-Gap , 1997, Molecular and cellular biology.

[35]  S. R. Datta,et al.  Akt Phosphorylation of BAD Couples Survival Signals to the Cell-Intrinsic Death Machinery , 1997, Cell.

[36]  H. Sugihara,et al.  Clonal analysis of superficial depressed‐type gastric carcinoma in humans , 1998, Cancer.

[37]  J. Ostrowski,et al.  Increased constitutive activity of mitogen-activated protein kinase and renaturable 85 kDa kinase in human-colorectal cancer. , 1998, British Journal of Cancer.

[38]  D. Pinkel,et al.  Retention of wild‐type p53 in tumors from p53 heterozygous mice: reduction of p53 dosage can promote cancer formation , 1998, The EMBO journal.

[39]  J. Graff,et al.  Smad3 Mutant Mice Develop Metastatic Colorectal Cancer , 1998, Cell.

[40]  John Calvin Reed,et al.  Regulation of cell death protease caspase-9 by phosphorylation. , 1998, Science.

[41]  A Luz,et al.  Apc1638N: a mouse model for familial adenomatous polyposis-associated desmoid tumors and cutaneous cysts. , 1998, Gastroenterology.

[42]  A. Sparks,et al.  Identification of c-MYC as a target of the APC pathway. , 1998, Science.

[43]  M. Taketo,et al.  Intestinal polyposis in mice with a dominant stable mutation of the β‐catenin gene , 1999, The EMBO journal.

[44]  R. Kucherlapati,et al.  Mouse models for colorectal cancer , 1999, Oncogene.

[45]  J. Nevins,et al.  Ras enhances Myc protein stability. , 1999, Molecular cell.

[46]  L. Luttrell,et al.  Activation of extracellular signal-regulated kinase in human prostate cancer. , 1999, The Journal of urology.

[47]  D. Latchman,et al.  Activation of the Bcl-2 promoter by nerve growth factor is mediated by the p42/p44 MAPK cascade. , 1999, Nucleic acids research.

[48]  Daniel Pinto,et al.  Regulatory Sequences of the Mouse Villin Gene That Efficiently Drive Transgenic Expression in Immature and Differentiated Epithelial Cells of Small and Large Intestines* , 1999, The Journal of Biological Chemistry.

[49]  A. Salomon,et al.  p53 mutation as a genetic trait of typical medullary breast carcinoma. , 1999, Journal of the National Cancer Institute.

[50]  Frank McCormick,et al.  Signalling networks that cause cancer. , 1999 .

[51]  P S Gartside,et al.  Transforming growth factor beta1 suppresses nonmetastatic colon cancer at an early stage of tumorigenesis. , 1999, Cancer research.

[52]  J. Downward,et al.  Multiple Ras Effector Pathways Contribute to G1Cell Cycle Progression* , 1999, The Journal of Biological Chemistry.

[53]  C. Marshall,et al.  Activation of mitogen-activated protein kinase is necessary but not sufficient for proliferation of human thyroid epithelial cells induced by mutant Ras , 1999, Oncogene.

[54]  H. Clevers,et al.  Linking Colorectal Cancer to Wnt Signaling , 2000, Cell.

[55]  Stanley R. Hamilton,et al.  Pathology and genetics of tumours of the digestive system , 2000 .

[56]  E. Wagner,et al.  Transgenic Activation of Ras in Neurons Promotes Hypertrophy and Protects from Lesion-Induced Degeneration , 2000, The Journal of cell biology.

[57]  R. Cox,et al.  Loss of heterozygosity in spontaneous and x‐ray–induced intestinal tumors arising in F1 hybrid Min mice: Evidence for sequential loss of Apc+ and Dpc4 in tumor development , 2000, Genes, chromosomes & cancer.

[58]  S. Scherer,et al.  Colorectal carcinomas in mice lacking the catalytic subunit of PI(3)Kγ , 2000, Nature.

[59]  C. Marshall,et al.  PI-3-kinase is an essential anti-apoptotic effector in the proliferative response of primary human epithelial cells to mutant RAS , 2000, Oncogene.

[60]  M. Tada,et al.  Transcriptional slippage of p53 gene enhanced by cellular damage in rat liver: monitoring the slippage by a yeast functional assay. , 2000, Mutation research.

[61]  F. McCormick,et al.  Opposing Effects of Ras on p53 Transcriptional Activation of mdm2 and Induction of p19ARF , 2000, Cell.

[62]  C. Der,et al.  Understanding Ras: 'it ain't over 'til it's over'. , 2000, Trends in cell biology.

[63]  R. Fodde,et al.  E-cadherin and adenomatous polyposis coli mutations are synergistic in intestinal tumor initiation in mice. , 2000, Gastroenterology.

[64]  Judith A. Blake,et al.  The Mouse Genome Database (MGD): integration nexus for the laboratory mouse , 2001, Nucleic Acids Res..

[65]  T. Mattfeldt,et al.  A murine tumor progression model for pancreatic cancer recapitulating the genetic alterations of the human disease. , 2001, Genes & development.

[66]  T. Takayama,et al.  Analysis of K-ras, APC, and beta-catenin in aberrant crypt foci in sporadic adenoma, cancer, and familial adenomatous polyposis. , 2001, Gastroenterology.

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

[68]  H. Sheng,et al.  Akt/PKB Activity Is Required for Ha-Ras-mediated Transformation of Intestinal Epithelial Cells* , 2001, The Journal of Biological Chemistry.

[69]  M. Mareel,et al.  Tumour biology. Weakening link to colorectal cancer , 2001 .

[70]  K. Kinzler,et al.  Mechanisms underlying losses of heterozygosity in human colorectal cancers , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[71]  M. Oren,et al.  Deregulated β‐catenin induces a p53‐ and ARF‐dependent growth arrest and cooperates with Ras in transformation , 2001, The EMBO journal.

[72]  S. Lowe,et al.  Oncogenic ras activates the ARF-p53 pathway to suppress epithelial cell transformation , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[73]  C. Der,et al.  Oncogenic Ras Blocks Anoikis by Activation of a Novel Effector Pathway Independent of Phosphatidylinositol 3-Kinase , 2001, Molecular and Cellular Biology.

[74]  A. Zauber,et al.  Molecular changes in the Ki‐ras and APC genes in colorectal adenomas and carcinomas arising in the same patient , 2001, The Journal of pathology.