Molecular Analysis of Motility in Metastatic Mammary Adenocarcinoma Cells
Abstract
Chemotaxis of metastatic MTLn3 cells towards EGF involves the rapid extension of lamellipods. We have characterized extending lamellipods in terms of the location and possible composition of the growth zones. Stimulation of MTLn3 cells with EGF causes a transient increase in actin nucleation activity resulting from the appearance of free barbed ends very close to the leading edge of extending lamellipods. Both actin polymerization and depolymerization are stimulated by EGF. The timing and location of EGF-induced actin nucleation activity in MTLn3 cells can account for the observed accumulation of F-actin at the leading edge and demonstrates that this F-actin rich zone is the primary actin polymerization zone after stimulation. Talin is present in the sites of actin nucleation with appropriate kinetics. Extension of lamellipods does not directly require adhesion to the substratum, but stabilization of lamellipods and focal contacts does depend on adhesion. EF1-alpha is also present in lamellipods, but is not localized to nucleation sites. These results identify a key area involved in metastatic cell motility and a potential regulatory molecule for that site - talin.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1996
- Accession Number
- ADB219006
Entities
People
- Jeffrey E. Segall
Organizations
- Yeshiva University