Robert M. DePhilip, Ph.D.
Associate Professor
dephilip.1@osu.edu
614-292-4769
614-292-7659
Appointments:
Associate Professor, Division of Anatomy and Medical Education
Education:
Ph.D.: University of Pittsburgh
Postdoctoral Training: University of North Carolina at Chapel Hill
Research Area:
The roll of cell adhesion molecules, called cadherins,
in embryonic development and in cancer.
Current Research:
Current focus is on the expression of P-cadherin during gonadogenesis. We
have demonstrated that the expression of P-cadherin is correlated with the
differentiation of the testis during mouse embryogenesis. P-cadherin is expressed
in Sertoli cells of the testis. After sexual differentiation in the female,
P-cadherin is no longer expressed in the ovary. In the male, P-cadherin seems
to be involved in segregation of germ cells into the sex cords. We would like
to determine how the P-cadherin gene is regulated in this sex-dependent manner.
A confounding piece of evidence is that the P-cadherin knockout mouse forms
a normal testis and is fertile. Thus, P-cadherin is not essential for testis
formation and its role in the knockout male mouse may be served by another
member of the cadherin family. We are investigaing cadherin expression in
the developing testis of the P-cadherin knockout mouse to determine what other
member of the cadherin family replaces P-cadherin during testis development.
Sorting out the sex-dependent expression of P-cadherin in the developing gonal
will provide insight into how genes are regulated in a sex-dependent manner.
Determining the mechanism of how one cadherin can substitute for another will
extend our understanding of gene reduncany and how one of two or more genes
is selected preferentially for expression.
We are also studying polymorphism in the promoter on the human E-cadherin
gene to determine if there is a correlation between certain polymorphisms
and the susceptibility to cancer. The expression of E-cadherin is known to
be down-regulated in certain types of epithelial cancers.
Techniques Available:
Immunohistochemistry, immunoblotting, PCR, Northern blotting, whole-mount
in situ hybridiation.
Representative Publications:
Gregory CW, DePhilip RM. Detection of steroidogenic acute regulatory
protein (StAR) in mitochondia of cultured rat Sertoli cells incubated with
follicle-stimulating hormone. Biology of Reproduction. 58(2): 470-4,
Feb 1998.
Lin LH, DePhilip RM. Sex-dependent expression of placental (P)-cadherin
during mouse gonadogenesis. Anatomical Record. 245(4): 535-44, Dec
1996.
Lin LH, DePhilip RM. Differential expression of placental (P)-cadherin
in Sertoli cells and peritubular myoid cells during postnatal development
of the mouse testis. Anatomical Record. 244(2): 155-64, Feb 1996.
Wu JC, Gregory CW, DePhilip RM. Expression of E-cadherin in immature
rat and mouse testis and in rat Sertoli cell cultures. Biology of Reproduction.
49(6): 1353-61, Dec 1993.