TY - JOUR
T1 - Regulation of protrusion shape and adhesion to the substratum during chemotactic responses of mammalian carcinoma cells
AU - Bailly, Maryse
AU - Yan, Lin
AU - Whitesides, George M.
AU - Condeelis, John S.
AU - Segall, Jeffrey E.
N1 - Funding Information:
The authors acknowledge the Analytical Imaging Facility at the Albert Einstein College of Medicine and particularly Michael Cam-mer for skillful help on microscopy and image analysis. The authors also acknowledge Dr. C. J. Chang from the Biostat Core at Albert Einstein College of Medicine for help on statistical analysis, Dr. Milan Mrksich for discussion regarding the nonadhesive substrata, Dr. Dong Qin for preparing special patterned samples, and members of the lab group meetings for helpful discussion. A link to the movie that was used to generate Figure 1 can be found on the bibliography pages of the Analytical Image Facility of the Albert Einstein College of Medicine web server (AECOM URL: http://www.aecom.yu.edu). This work was supported by grants USAMRDC 2466 (JES), GM38511 (JSC), and GM30367 (GMW). J.S. is supported by an Established Scientist Award from the New York City Af®liate of the American Heart Association.
PY - 1998/6/15
Y1 - 1998/6/15
N2 - We report here the first direct observation of chemotaxis to EGF by rat mammary carcinoma cells. When exposed to a gradient of EGF diffusing from a micropipette, MTLn3 cells displayed typical ameboid chemotaxis, extending a lamellipod-like protrusion and moving toward the pipette. Using a homogeneous upshift in EGF to model stimulated lamellipod extension (J. E. Segall et al., 1996, Clin. Exp. Metastasis 14, 6172), we analyzed the relationship between adhesion and chemoattractant-stimulated protrusion. Exposure to EGF led to a rapid remodeling of the adhesive contacts on adherent cells, in synchrony with extension of a flat lamellipod over the substratum. EGF-stimulated lamellipods still extended in the presence of adhesion, blocking peptides or over nonadhesive surfaces. They were, however, slightly shorter and retracted rapidly under those conditions. The major protrusive structure observed on well-spread, adherent cells, after EGF stimulation was a flat broad lamellipod, whether or not in contact with the substratum, while cells in suspension showed transient protrusive activity over the entire cell surface. We conclude that the initial adhesive status of the cell conditions the shape of the outcoming protrusion. Altogether our results suggest that, although adhesive contacts are not necessary for lamellipod extension, they play a role in stabilizing the protrusion as well as in the control of its final shape and amplitude.
AB - We report here the first direct observation of chemotaxis to EGF by rat mammary carcinoma cells. When exposed to a gradient of EGF diffusing from a micropipette, MTLn3 cells displayed typical ameboid chemotaxis, extending a lamellipod-like protrusion and moving toward the pipette. Using a homogeneous upshift in EGF to model stimulated lamellipod extension (J. E. Segall et al., 1996, Clin. Exp. Metastasis 14, 6172), we analyzed the relationship between adhesion and chemoattractant-stimulated protrusion. Exposure to EGF led to a rapid remodeling of the adhesive contacts on adherent cells, in synchrony with extension of a flat lamellipod over the substratum. EGF-stimulated lamellipods still extended in the presence of adhesion, blocking peptides or over nonadhesive surfaces. They were, however, slightly shorter and retracted rapidly under those conditions. The major protrusive structure observed on well-spread, adherent cells, after EGF stimulation was a flat broad lamellipod, whether or not in contact with the substratum, while cells in suspension showed transient protrusive activity over the entire cell surface. We conclude that the initial adhesive status of the cell conditions the shape of the outcoming protrusion. Altogether our results suggest that, although adhesive contacts are not necessary for lamellipod extension, they play a role in stabilizing the protrusion as well as in the control of its final shape and amplitude.
KW - Adhesion
KW - Cancer cells
KW - Chemotaxis
KW - Lamellipod extension
KW - Protrusion
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U2 - 10.1006/excr.1998.4031
DO - 10.1006/excr.1998.4031
M3 - Article
C2 - 9637770
AN - SCOPUS:17144460611
SN - 0014-4827
VL - 241
SP - 285
EP - 299
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -