Wide spectrum of tumors in knock-in mice carrying a Cdk4 protein insensitive to INK4 inhibitors.
We have introduced a point mutation in the first coding exon of the locus encoding the cyclin-dependent kinase 4 (Cdk4) by homologous recombination in embryonic stem cells. This mutation (replacement of Arg24 by Cys) was first found in patients with hereditary melanoma and renders Cdk4 insensitive to INK4 inhibitors. Here, we report that primary embryonic fibroblasts expressing the mutant Cdk4R24C kinase are immortal and susceptible to transformation by Ras oncogenes. Moreover, homozygous Cdk4(R24C/R24C) mutant mice develop multiple tumors with almost complete penetrance. The most common neoplasia (endocrine tumors and hemangiosarcomas) are similar to those found in pRb(+/-) and p53(-/-) mice. This Cdk4 mutation cooperates with p53 and p27(Kip1) deficiencies in decreasing tumor latency and favoring development of specific tumor types. These results provide experimental evidence for a central role of Cdk4 regulation in cancer and provide a valuable model for testing the potential anti-tumor effect of Cdk4 inhibitors in vivo.
Sotillo
R
R
Molecular Oncology Program, Centro Nacional de Investigaciones Oncológicas, Melchor Fernández Almagro 3 E-28029 Madrid, Spain.
Dubus
P
P
Martín
J
J
de la Cueva
E
E
Ortega
S
S
Malumbres
M
M
Barbacid
M
M
D016475:3T3 Cells; D000483:Alleles; D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics; D051358:Cyclin-Dependent Kinase 4; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000037:antagonists & inhibitors*; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000235:genetics* / Q000502:physiology*; D005091:Exons; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D016158:Genes, p53 / Q000235:genetics; D011905:Genes, ras / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006720:Homozygote; D006801:Humans; D008223:Lymphoma / Q000235:genetics; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009154:Mutation; D017354:Point Mutation; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D011518:Proto-Oncogene Proteins; D011995:Recombination, Genetic; D012509:Sarcoma / Q000235:genetics; D012737:Sex Factors; D013724:Teratoma / Q000235:genetics; D013997:Time Factors; D014170:Transformation, Genetic; D025803:Tumor Suppressor Protein p14ARF / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics
C493961:Cdkn1b protein, mouse; D018797:Cell Cycle Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D011518:Proto-Oncogene Proteins; D025803:Tumor Suppressor Protein p14ARF; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; C495900:CDK4 protein, human; C495902:Cdk4 protein, mouse; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases