Expression of periostin in human breast cancer.
BACKGROUND
Periostin is a secreted adhesion protein, normally expressed in mesenchime-derived cells. Aberrant expression of the periostin gene in epithelial tumours seems to play a role in angiogenesis and metastases.


OBJECTIVE
To investigate periostin expression in a consecutive series of breast carcinomas and correlate it with established biological and prognostic factors.


METHODS
A consecutive series of 206 breast carcinomas was investigated by immunohistochemistry with a specific antiperiostin antibody. Immunohistochemical expression of oestrogen and progesterone receptors, Ki-67 (MIB-1), HER-2/neu, VEGF-A, VEGFR-1 and VEGFR-2 was analysed. Periostin expression was also investigated in MCF-7 and MDA-468 cell lines by immunohistochemistry, western blot and quantitative RT-PCR. Localisation of periostin was investigated in MCF-7 cells by the green fluorescent protein (GFP) approach.


RESULTS
Periostin was highly expressed in carcinoma cells, but not in normal breast tissues. The pattern of expression was mainly cytoplasmic. However, in 12% of cases a nuclear reactivity was observed. Nuclear periostin significantly correlated with tumour size, and with expression of oestrogen receptor, progesterone receptor, VEGF-A, VEGFR-1 and VEGFR-2. A nuclear localisation of periostin was also observed in MCF-7 and MDA-468 cell lines. In MCF-7 cells the nuclear localisation of periostin was also shown by transfection of a vector expressing a GFP-periostin chimeric protein.


CONCLUSIONS
Results indicate that the aberrant gene expression of periostin in breast cancer cells is associated with an abnormal nuclear localisation of the protein. The nuclear localisation of periostin in breast cancer may induce significant biological effects.
Puglisi
F
F
Dipartimento di Oncologia, Azienda Ospedaliero-Universitaria di Udine, Italy.
Puppin
C
C
Pegolo
E
E
Andreetta
C
C
Pascoletti
G
G
D'Aurizio
F
F
Pandolfi
M
M
Fasola
G
G
Piga
A
A
Damante
G
G
Di Loreto
C
C
D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D018275:Carcinoma, Lobular / Q000378:metabolism* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D006801:Humans; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; D009363:Neoplasm Proteins; C512835:POSTN protein, human; D012333:RNA, Messenger; D012334:RNA, Neoplasm