| First Author | Sotgia F | Year | 2006 |
| Journal | Cancer Res | Volume | 66 |
| Issue | 22 | Pages | 10647-51 |
| PubMed ID | 17108100 | Mgi Jnum | J:116126 |
| Mgi Id | MGI:3693032 | Doi | 10.1158/0008-5472.CAN-06-2805 |
| Citation | Sotgia F, et al. (2006) Caveolin-1, mammary stem cells, and estrogen-dependent breast cancers. Cancer Res 66(22):10647-51 |
| abstractText | Estrogen exposure is considered a significant risk factor for breast cancer development. Estrogen receptor (ER) alpha is expressed at low levels in normal epithelia, and its expression is dramatically up-regulated as transformation progresses during mammary hyperplasia and adenocarcinoma development. The mechanism(s) driving ERalpha up-regulation during mammary tumorigenesis remains unclear. Caveolin-1 (Cav-1) is the structural protein of plasmalemmal invaginations, termed caveolae, which functions as a tumor suppressor gene. Interestingly, Cav-1 dominant-negative mutations are exclusively found in ERalpha-positive breast cancer samples. In support of these clinical findings, ERalpha expression is increased in Cav-1 (-/-) null mammary epithelia, and estrogen stimulation further enhances the growth of Cav-1-deficient three-dimensional epithelial structures. These phenotypes correlate with augmented levels of cyclin D1. In addition, Cav-1 gene inactivation induces the accumulation of a cell population with the characteristics of adult mammary stem cells. Primary cultures of Cav-1 (-/-) mammary epithelial cells exhibit premalignant changes, such as abnormal lumen formation, epidermal growth factor-independent growth, defects in cell substrate attachment, and increased cell invasiveness. Thus, Cav-1 gene inactivation promotes premalignant alterations in mammary epithelia and induces increased ERalpha expression levels and the up-regulation of cyclin D1. As tumor formation is a multihit process, Cav-1 mutations that occur during the early stages of mammary transformation may be a critical upstream/initiating event leading to increased ERalpha levels. |
