Insulin-like growth factor and epidermal growth factor independence in human mammary carcinoma cells with c-erbB-2 gene amplification and progressively elevated levels of tyrosine-phosphorylated p185erbB-2
Abstract
Growth factor-independent proliferation is an essential aspect of the transformation process. To study the influence of c-erbB-2 overexpression on the autonomous growth of human mammary cancer cells, we used a series of non-neoplastic and neoplastic human mammary epithelial cell lines isolated from a patient with intraductal and invasive ductal carcinoma of the breast. The non-neoplastic cell line, H16N-2, which expresses a normal level (single gene copy) of c-erbB-2, was used for comparison with the neoplastic cell lines. Both the metastatic tumor cell lines, 21MT-1 and 21 MT-2, showed equivalent amplification of the c-erbB-2 gene; however, 21MT-1 cells showed a higher level of c-erbB-2 overexpression. Therefore, the H16N-2, 21MT-2, and 21MT-1 cell series forms a distinct gradient of progressively increasing c-erbB-2 gene expression. Furthermore, the overexpression of c-erbB-2 in the 21MT cell lines was concordant with increases in the constitutive tyrosine kinase activity of p185erb-2 measured in the absence of exogenous growth factors in culture. Normal mammary epithelial cells require both insulin-like growth factor (IGF)-l (or supraphysiological concentrations of insulin) and epidermal growth factor (EGF) to proliferate un...Continue Reading
References
Transformation of NIH 3T3 cells by overexpression of the normal coding sequence of the rat neu gene.
Citations
Related Concepts
Related Feeds
Breast Invasive Carcinoma
Invasive breast cancers indicate a spread into breast tissues and lymph nodes. Here are the latest discoveries pertaining to breast invasive carcinomas.
Carcinoma, Ductal
Ductal carcinoma is a malignant neoplasm involving the ductal systems of any of a number of organs, such as the mammary glands, pancreas, prostate or lacrimal gland. Discover the latest research on ductal carcinoma here.
Breast Invasive Carcinoma (Keystone)
Invasive breast cancers indicate a spread into breast tissues and lymph nodes. Here are the latest discoveries pertaining to breast invasive carcinomas.