Caveolin-1 is down-regulated and inversely correlated with HER2 and EGFR expression status in invasive ductal carcinoma of the breast.
OBJECTIVE
To evaluate the caveolin-1 status of invasive ductal carcinoma and its correlation with other important parameters of breast carcinogenesis. Caveolin-1, the main structural protein of caveolae, is involved in the regulation of several intracellular signalling pathways and also functions as a tumour suppressor in breast carcinogenesis.


RESULTS
One hundred and thirty cases of invasive ductal carcinomas with matched normal breast tissue were evaluated immunohistochemically for caveolin-1 expression. Using a tissue microarray, caveolin-1 expression was also correlated with the expression of other antigens such as eostrogen receptor, progesterone receptor, epidermal growth factor receptor (EGFR), HER2, beta-catenin, E-cadherin, p53, Ki67 and with clinicopathological parameters. Immunohistochemical results showed strong expression of caveolin-1 in all normal breast epithelial cells, but a reduction of caveolin-1 expression in 56 cases (43.1%) of invasive ductal carcinoma. Furthermore, a statistically significant inverse correlation between caveolin-1 and EGFR and HER2 was noted (P < 0.001).


CONCLUSIONS
Our results indicate a reduction in caveolin-1 expression in invasive ductal carcinoma of the breast, which supports in vitro studies of its role as a tumour suppressor. Caveolin-1 also shows an inverse correlation with EGFR and HER2, which fits with its function as a negative regulator of signal transduction.
Park
S-S
SS
Department of Pathology, Dongguk University International Hospital, Seoul, Korea.
Kim
J E
JE
Kim
Y A
YA
Kim
Y C
YC
Kim
S-W
SW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D015820:Cadherins / Q000032:analysis / Q000378:metabolism; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D051242:Caveolin 1 / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D066246:ErbB Receptors / Q000032:analysis / Q000378:metabolism; D005260:Female; D018773:Genes, erbB-1; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis / Q000378:metabolism; D046228:Microarray Analysis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000032:analysis / Q000378:metabolism; D011980:Receptors, Progesterone / Q000032:analysis / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000378:metabolism; D051176:beta Catenin / Q000032:analysis / Q000378:metabolism
D014408:Biomarkers, Tumor; D015820:Cadherins; D051242:Caveolin 1; D066246:ErbB Receptors; D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D016159:Tumor Suppressor Protein p53; D051176:beta Catenin