Accession Number : ADA332591

Title :   TGF-alpha Expression During Breast Tumorigenesis

Descriptive Note : Annual rept. 1 Jul 96-30 Jun 97

Corporate Author : CINCINNATI UNIV OH

Personal Author(s) : Taylor, Kevin

PDF Url : ADA332591

Report Date : JUL 1997

Pagination or Media Count : 21

Abstract : Transforming Growth Factor a (TGF alpha) is an oncogenic growth factor which drives estrogen independent breast tumor proliferation via an autocrine loop. Its receptor, epidermal growth factor receptor (EGER), is also a proto oncogene, which in breast tumors may be overexpressed by gene amplification. In contrast, in normal breast TGFa and EGFR are expressed in an estrogen dependent, cell specific manner as part of an intercellular paracrine loop. The function of this paracrine loop is unknown. This proposal defines the role of TGF alpha/EGFR in the early steps of tumor progression prior to invasion by defining the cell-specific expression of TGF alpha and EGFR in normal and premalignant breast tissue. We have shown TGF alpha mRNA expression in eight breast cancer cell lines by either Northern blot analysis or in situ hybridization. In addition, we have shown TGFR protein expression by Western blot analysis in the eight cell lines and in freshly isolated tissue. Interestingly, fresh tissue sample express predominantly the soluble (6 kD) form of TGFR, unlike the cell lines which express mostly the transmembrane form of TGF alpha. Although more tissue samples are needed, this may indicate a difference in TGFR processing between transformed and non-transformed breast epithelium.

Descriptors :   *BREAST CANCER, TISSUES(BIOLOGY), GROWTH(GENERAL), NEOPLASMS, GENES, CELLS(BIOLOGY), MAMMARY GLANDS.

Subject Categories : Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE