title: Modeling breast cancer in vivo and ex vivo reveals an essential role of Pin1 in tumorigenesis.
abstract: Phosphorylation on certain Ser/Thr-Pro motifs is a major oncogenic mechanism. The conformation and function of phosphorylated Ser/Thr-Pro motifs are further regulated by the prolyl isomerase Pin1. Pin1 is prevalently overexpressed in human cancers and implicated in oncogenesis. However, the role of Pin1 in oncogenesis in vivo is not known. We have shown that Pin1 ablation is highly effective in preventing oncogenic Neu or Ras from inducing cyclin D1 and breast cancer in mice, although it neither affects transgene expression nor mammary gland development. Moreover, we have developed an ex vivo assay to uncover that a significant fraction of primary mammary epithelial cells from Neu or Ras mice display various malignant properties long before they develop tumors in vivo. Importantly, these early transformed properties are effectively suppressed by Pin1 deletion, which can be fully rescued by overexpression of cyclin D1. Thus, Pin1 is essential for tumorigenesis and is an attractive anticancer target. Our ex vivo assay can be used to study early events of breast cancer development in genetically predisposed mice.
authors.affiliation: Cancer Biology Program, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Gerburg
authors.initials: G
authors.lastname: Wulf
authors.forename: Priti
authors.initials: P
authors.lastname: Garg
authors.forename: Yih-Cherng
authors.initials: YC
authors.lastname: Liou
authors.forename: Dirk
authors.initials: D
authors.lastname: Iglehart
authors.forename: Kun Ping
authors.initials: KP
authors.lastname: Lu
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002454:Cell Differentiation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002478:Cells, Cultured; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D008297:Male; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D008822:Mice, Transgenic; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D012746:Sexual Abstinence; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D019938:Cyclin D1; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase; D016271:Proto-Oncogene Proteins c-myc; D018719:Erb-b2 Receptor Tyrosine Kinases; D018631:ras Proteins; C000606846:PIN1 protein, human; C000606850:Pin1 protein, mouse