COX-2 localization within plasma membrane caveolae-like structures in human lobular intraepithelial neoplasia of the breast.
Cyclooxygenase-2 (COX-2) is highly expressed in human intraepithelial neoplasia of the breast and takes part in the molecular pathway implicated in progression of breast cancer. Recently, we demonstrated that COX-2 protein is mainly located in plasma membrane of lobular intraepithelial neoplasia (LIN) cells suggesting a localization in caveolae-like structures. The aim of the present study is to establish subcellular locations of COX-2 and its colocalization with caveolin-1 (CAV-1) to caveolae structures in LIN. To establish a relationship between COX-2 and CAV-1, 39 LINs were studied by immunohistochemistry and confocal microscopy analysis. COX-2 and CAV-1 expression was observed respectively in 79.5 and in 94.9% of LIN studied. A positive correlation was found between membrane COX-2 staining pattern and CAV-1 expression, while no correlation was found between cytoplasm COX-2 staining pattern and CAV-1. Confocal analysis showed that COX-2 localized to plasma membrane was strictly associated to CAV-1 suggesting that an amount of COX-2 protein is placed in caveolae-like structures. Our results show that COX-2 is localized within caveolae compartment and colocalized with CAV-1 protein in LIN lesions. Because caveolae are rich in signaling molecules, this COX-2 compartment may play an important role in diverse breast cancer carcinogenesis processes.
Perrone
Giuseppe
G
Surgical Pathology, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, 200, 00128 Rome, Italy. g.perrone@unicampus.it
Zagami
Mariagiovanna
M
Altomare
Vittorio
V
Battista
Cleonice
C
Morini
Sergio
S
Rabitti
Carla
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000201:enzymology*; D002278:Carcinoma in Situ / Q000201:enzymology*; D018275:Carcinoma, Lobular / Q000201:enzymology*; D021941:Caveolae / Q000201:enzymology*; D051242:Caveolin 1 / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged
D014408:Biomarkers, Tumor; C495540:CAV1 protein, human; D051242:Caveolin 1; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human