| First Author | Howe LR | Year | 2005 |
| Journal | Cancer Res | Volume | 65 |
| Issue | 21 | Pages | 10113-9 |
| PubMed ID | 16267038 | Mgi Jnum | J:102694 |
| Mgi Id | MGI:3607946 | Doi | 10.1158/0008-5472.CAN-05-1524 |
| Citation | Howe LR, et al. (2005) HER2/neu-induced mammary tumorigenesis and angiogenesis are reduced in cyclooxygenase-2 knockout mice. Cancer Res 65(21):10113-9 |
| abstractText | The inducible prostaglandin synthase cyclooxygenase-2 (Cox-2) is overexpressed in approximately 40% of human breast cancers and at higher frequencies in preinvasive ductal carcinoma in situ (DCIS). Cox-2 expression is particularly associated with overexpression of human epidermal growth factor receptor 2 (HER2/neu). To definitively interrogate the role of Cox-2 in mammary neoplasia, we have used a genetic approach, crossing Cox-2-deficient mice with a HER2/neu transgenic strain, MMTV/NDL. At 20 weeks of age, mammary glands from virgin MMTV/NDL females contained multiple focal tumors, or mammary intraepithelial neoplasias, which histologically resembled human DCIS. Mammary tumor multiplicity and prostaglandin E2 (PGE2) levels were significantly decreased in Cox-2 heterozygous and knockout animals relative to Cox-2 wild-type controls. Notably, the proportion of larger tumors was decreased in Cox-2-deficient mice. HER2/neu-induced mammary hyperplasia was also substantially reduced in Cox-2 null mice. Additionally, mammary glands from Cox-2 knockout mice exhibited a striking reduction in vascularization, and expression of proangiogenic genes was correspondingly reduced. Decreased vascularization was observed both in dysplastic and normal-appearing regions of Cox-2-null mammary glands. Our data provide the first genetic evidence that Cox-2 contributes to HER2/neu-induced mammary tumorigenesis. This finding may help to explain the reduced risk of breast cancer associated with regular use of nonsteroidal anti-inflammatory drugs. |
