The Role of Integrins and IGFBPs in the IGF-1 Stimulated Migration of Human Breast Cancer Cells
Abstract
We have previously established that IGF-I can stimulate chemotaxis of MCF-7 and MDA-231 human breast cancer cells. We now report that two closely related peptides, IGF-II and des(1-3)IGF-I are also capable of inducing directional migration in these two cell lines. Interestingly, neither is as potent as native IGF-I. Examination of two other growth factors, hepatocyte growth factor and TGF-alpha yielded markedly different results. While both were able to stimulate MDA-231 cells to migrate, TGF-alpha was found to be the first non-IGF mitogen able to induce a significant response in the MCF-7 cells. Migration assays done with anti-integrin antibodies revealed that the alpha3 subunit is not required for MCF-7 cells to migrate through Type IV collagen. However, alpha3 plays some role in the MDA-231' cells' migration through laminin. Exposure to calf serum does not increase the number of Type IIGF receptors in the MCF-7 cells, as assessed by IGF-I-crosslinking studies. Differences in the amounts of IGFBPs secreted by MCF-7 cells may partially explain the enhanced migration seen after calf serum exposure. Pre-incubation with IGFBP-1 did not inhibit MCF-7 migration to IGF-I. The effect of IGFBP-1 on MDA-231 cell migration will require further study for a definitive conclusion to be drawn.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1997
- Accession Number
- ADB235510
Entities
People
- David D. Clemmons
- Monica E. Doerr
Organizations
- University of North Carolina at Chapel Hill