Multifunctional cytokines play important and only partially defined roles in mammary tumor development and progression. Normal human mammary epithelial cells (MECs) constitutively produce interleukin (IL) 6, IL8, and a nonsecreted form of tumor necrosis factor. MEC transformation by different oncogenes is frequently associated with alterations of cytokine/growth factor production and responsiveness. This seems particularly true in the case of IL6. Histochemical studies showed that expression of immunoreactive IL6, as compared to normal tissue and to in situ lesions, is significantly reduced in invasive ductal carcinoma. Conversely, the expression of IL6 in invasive lobular carcinoma was enhanced. Expression of TGF-β1 in mammary neoplasia was in general less intense than that seen in the normal mammary gland. In vitro studies partially supported the in vivo findings: expression of IL6 and TGF-β1 was significantly down-regulated in cultures derived from both ductal carcinoma and peritumoral tissue. Similarly, responsiveness to IL6 and TGF- β1 was significantly reduced in neoplastic MECs. The data suggest that alterations of cytokine pathways are present not only in mammary neoplasia, but also in pathologically unaffected breast tissues.
|Number of pages||5|
|Publication status||Published - Jul 1 1996|
ASJC Scopus subject areas
- Cancer Research