title: Role of PTHrp and PTHrp-engaged pathways in MCF-7 cells migration/invasion.
abstract: In this paper the effect of N-terminal parathyroid hormone-related protein (PTHrp) and PTHrp-engaged pathways on MCF-7 breast cancer cell migration/invasivity and matrix metalloproteinases (MMPs) production were investigated. We found that: a) migration is not affected by PTHrp and Forskolin (FK)-activated PKA, while Phorbol Myristate Acetate (PMA)-activated PKC strongly stimulates MCF-7 cells motility. b) MMPs production was unaffected by PTHrp, but FK reduced membrane-type (MT)-1 MMP expression. Conversely, PMA induced a marked increase of MT1-MMP and MMP-9. c) Chemical activation of PKC is not sufficient, by itself, to confer invasive ability to MCF-7 cells, unless they were provided with additional factors, supplied by fibroblasts. d) Matrix invasion likely occurs through an activation cascade, involving at least three components: pro-MMP-9 and MT-1 MMP (supplied by PMA-stimulated MCF-7 cells) and pro MMP-2 (supplied by fibroblasts). e) The selective chemical inhibition of the adenylylciclase (AC)/PKA and phospholipase C (PLC)/PKC pathways confirmed that MCF-7 cells invasivity is not affected by exogenous PTHrp, which can only modulate their growth. However, the PTHrp responsibility in breast cancer invasion cannot be completely excluded. Indeed, fibroblasts are known to respond to PTHrp (which is a normal product of MCF-7 as well as other breast cancer cells) with enhanced release of MMP-2. On the basis of the documented requirement of fibroblast-derived MMP-2 for MCF-7 cell invasivity, a novel humoral fibroblast-breast cancer cell interaction, mediated by PTHrp, can be recognised.
authors.affiliation: Department of Physiology, University of Siena, via Aldo Moro, 53100 Siena, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Torricelli
authors.forename: Vittoria
authors.initials: V
authors.lastname: Fortino
authors.forename: Elisa
authors.initials: E
authors.lastname: Capurro
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sacchi
authors.forename: Paola
authors.initials: P
authors.lastname: Ponzo
authors.forename: Adriana
authors.initials: A
authors.lastname: Pacini
authors.forename: Michela
authors.initials: M
authors.lastname: Muscettola
authors.forename: Emanuela
authors.initials: E
authors.lastname: Maioli
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D005260:Female; D006801:Humans; D009361:Neoplasm Invasiveness; D044162:Parathyroid Hormone-Related Protein / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D044162:Parathyroid Hormone-Related Protein