Ruy Tchao, PhD
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Ruy Tchao, Ph.D.
BS (Nottingham); PhD (Manchester)
Professor of Pharmacology and Toxicology
Email: r.tchao@usp.edu
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Research Interests
Tumor cell motility and invasion
It is generally believed that tumor cell motility is one of the factors involved in tumor invasion of normal tissues and blood capillaries. The malignant nature of a tumor is characterized by its invasiveness. In this research project we are studying the role of desmosomes in the motility and invasion of several clones isolated from a squamous carcinoma cell line. Cell motility and division are studied by time lapse video microscopy, desmosomes are studied by specific antibody staining and gel electrophoresis. Drugs that induce cell differentiation will be studied in this system. Synthetic peptides that influence cell adhesion to the substrate will be studied for effects on cell motility. Finally invasiveness will be studied in an in-vitro invasion assay.
Development of in-vitro assays as alternatives to the Draize rabbit eye test
The Draize eye irritancy test has been widely criticized scientifically and for ethical use of the animals. In recent years there has been increased need for developing new and better in-vitro techniques as Draize alternatives for the evaluation of commercial products. The integrity of corneal permeability is the first physiological event to be compromised when an irritant interacts with the eye. In tissue culture we are using an epithelial cell line with similar trans-epithelial permeability to study the effect of various agents on the epithelium. The diffusion of Na-fluorescein from the apical side to the basal side of the epithelium is used as a quantitative measure of epithelial permeability. Various surfactants and commercial products are being studied in this in-vitro assay.