George Plopper

Associate Professor: Department of Biology, Department of Biomedical Engineering

Education and Training

B.S. University of California, San Diego
Biology 

Ph.D. Harvard University Medical School
Cell and Developmental Biology

George Plopper received his bachelors degree in Biology from the University of California, San Diego. He received his Ph.D. in Cell and Developmental Biology from Harvard University Medical School, working under the supervision of Dr. Don Ingber in the Department of Surgical Research at Children's Hospital in Boston. Dr. Plopper worked for four years at Desmos, Inc., in San Diego, in conjunction with Dr. Vito Quaranta's laboratory at The Scripps Research Institute in La Jolla, CA. He also served as Assistant Professor in Biological Sciences at the University of Nevada, Las Vegas for four years before arriving at Rensselaer Polytechnic Institute in 2001. Dr. Plopper's research interests include cell-extracellular matrix interactions, cell signaling, stem cell biology, cancer cell biology, and tissue engineering. He is a member of the American Society for Cell Biology, the American Association for Cancer Research, the In Vitro Society, and the American Association for the Advancement of Science.

Contact

E-mail: ploppg@rpi.edu
Website: http://www.rpi.edu/~ploppg
Tel: (518) 276-8288
Fax: (518) 276-2851

Office: CBIS 2115

Rensselaer Polytechnic Institute
110 8th Street
Troy NY 12180-3596

Research Interests

Cell-extracellular matrix interactions, cell signaling, stem cell biology, cancer cell biology, and tissue engineering.

Dr. Plopper's research laboratory is primarily concerned with determining how cellular adhesion to extracellular matrix (ECM) molecules elicits specific cellular responses, including growth, differentiation, and migration. We work with two model systems: human mesenchymal stem cells adhering to purified ECM proteins, and human breast cancer cells interacting with bovine lung endothelial cells plated on purified ECM proteins. Our general hypothesis is that adhesion to ECM molecules activates a subset of intracellular signaling pathways associated with integrin receptors, and that this signaling controls cell behaviors by modulating the organization of the cytoskeleton. Our research has both basic and applied elements, and is organized into three major projects:

• Differentiation of mesenchymal stem cells plated on defined ECM proteins: We are defining the effect of ECM contact on human mesenchymal stem cell differentiation. Our hypothesis is that contact with distinct ECM proteins stimulates specific integrin-associated signaling pathways that ultimately control the differentiation of these cells into bone-, cartilage-, or fat-producing cells.
• Functional dissection of laminin domains: This project aims to identify how cell adhesion receptors and signaling molecules control the growth, migration and differentiation of cells plated on domains of the ECM protein laminin-332. Our hypothesis is that distinct populations of ECM receptors (e.g., integrins alpha3beta1, alpha6beta1and alpha6beta4) bind to distinct regions of laminin-332 and control signaling pathways independently, but that they act in concert to modulate growth and differentiation of stem cells.
• Modulation of cancer cell migration by boric acid derivatives. In collaboration with Dr. Steven Carper at the University of Nevada, we are researching the mechanisms that govern how boric acid and its structural derivatives influence the migration of breast and prostate cancer cells.

Selected Publications

Ward, D.F., Salasznyk, R.M., Klees, R.F, Backiel, J., Boskey, A. and Plopper, G.E. Mechanical strain enhances ECM induced cell fate determination and promotes osteogenic differentiation of human mesenchymal stem cells through the ERK MAPK pathway. Stem Cells & Development, Jun;16(3):467-80, 2007.

Salasznyk, R.M., Klees, R.F, Vandenberg, S., Bennett, K, and Plopper, G.E. Laminin-5 activates extracellular matrix production and osteogenic gene focusing in human mesenchymal stem cells. Matrix Biology, Mar;26(2):106-14, 2007

Klees, R.F., Salasznyk, R.M., Boskey, A. and Plopper, G.E. Activation of FAK is necessary for the osteogenic differentiation of human mesenchymal stem cells on laminin-5. Journal of Cellular Biochemistry, Feb 1;100(2):499-514, 2007.

Salasznyk,R.M., Klees, R.F., Williams, W.A., Boskey, A, and Plopper, G.E. Focal adhesion kinase signaling pathways regulate the osteogenic differentiation of human mesenchymal stem cells. Experimental Cell Research, Jan 1;313(1):22-37, 2007.

Liu, H., Plopper, G., Earley, S., Chen, Y., Ferguson, B., and Zhang X.-C. Sensing minute changes in biological cell monolayers by THz differential time-domain spectroscopy. Biosensors and Bioelectronics, Jan 15;22(6):1075-80, 2007.

Plopper, G.E. Extracellular matrix and cell junctions. In: Cells, Lewin, B., Cassimeris, L., Lingappa, V.R., Plopper, G., editors. Jones & Bartlett, Sudbury MA, pp. 645-702, 2006.