title: Cyclin A1 modulates the expression of vascular endothelial growth factor and promotes hormone-dependent growth and angiogenesis of breast cancer.
abstract: Alterations in cellular pathways related to both endocrine and vascular endothelial growth factors (VEGF) may contribute to breast cancer progression. Inhibition of the elevated levels of these pathways is associated with clinical benefits. However, molecular mechanisms by which endocrine-related pathways and VEGF signalling cooperatively promote breast cancer progression remain poorly understood. In the present study, we show that the A-type cyclin, cyclin A1, known for its important role in the initiation of leukemia and prostate cancer metastasis, is highly expressed in primary breast cancer specimens and metastatic lesions, in contrasting to its barely detectable expression in normal human breast tissues. There is a statistically significant correlation between cyclin A1 and VEGF expression in breast cancer specimens from two patient cohorts (p<0.01). Induction of cyclin A1 overexpression in breast cancer cell line MCF-7 results in an enhanced invasiveness and a concomitant increase in VEGF expression. In addition, there is a formation of protein-protein complexes between cyclin A1 and estrogen receptor ER-α cyclin A1 overexpression increases ER-α expression in MCF-7 and T47D cells. In mouse tumor xenograft models in which mice were implanted with MCF-7 cells that overexpressed cyclin A1 or control vector, cyclin A1 overexpression results in an increase in tumor growth and angiogenesis, which is coincident with an enhanced expression of VEGF, VEGFR1 and ER-α Our findings unravel a novel role for cyclin A1 in growth and progression of breast cancer, and suggest that multiple cellular pathways, including cell cycle regulators, angiogenesis and estrogen receptor signalling, may cooperatively contribute to breast cancer progression.
authors.affiliation: Department of Clinical Sciences, Lund University, Malmö, Sweden.
authors.forename: Azharuddin Sajid
authors.initials: AS
authors.lastname: Syed Khaja
authors.forename: Nishtman
authors.initials: N
authors.lastname: Dizeyi
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Kopparapu
authors.forename: Lola
authors.initials: L
authors.lastname: Anagnostaki
authors.forename: Pirkko
authors.initials: P
authors.lastname: Härkönen
authors.forename: Jenny Liao
authors.initials: JL
authors.lastname: Persson
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D056750:Cyclin A1 / Q000235:genetics* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D061986:MCF-7 Cells; D008325:Mammary Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics* / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism
chemical_list: D056750:Cyclin A1; D047628:Estrogen Receptor alpha; D042461:Vascular Endothelial Growth Factor A; D049452:Green Fluorescent Proteins; D040281:Vascular Endothelial Growth Factor Receptor-1