Research Summary

We are the first group to demonstrate inhibitory effects of calcitriol in canine cancer and normal cell lines. We demonstrated that calcitriol, EB1089, and analog V inhibit cell proliferation in SCC 2/88 cells. Calcitriol PTHrP mRNA expression and reduced stimulatory effect of TGF-β on PTHrP mRNA expression in SCC 2/88 cells. In Normal Prostate Primary Culture in Dogs: We demonstrated that VDR mRNA and 1α-OHase mRNA were present in both the epithelium and stroma of the canine prostate gland and primary cultures. VDR levels were higher in epithelial cells than in stromal cells. 1,25(OH)₂D₃, 25(OH)₂D₃, and EB1089 inhibited epithelial cell growth at 10^-7M. In contrast, 1,25(OH)₂D₃ and EB1089 at 10^-7M stimulated stromal cell growth. 1,25(OH)₂D₃ and its analogs may be an effective antiproliferative agent of epithelial cells in certain types of prostate cancer.

Research Funding

1. In Vitro Effects of 1,25(OH)₂D_3; analog EB 1089; and Medium Chain Triglyceride on Cell Growth and Vitamin D Receptor Expression in Canine Transitional Cell Carcinoma of the Urinary Bladder.
   Principal Investigator: Dr. N Inpanbutr
   Source: The Canine Research Funds
   Co-investigators: Drs. Bill Kisselberth, CC Capen, T. Kaewsakhorn
   Collaborator: Dr. Martin Calverley, Leo Pharma Co. Denmark
2. Effects of 1α, 25-dihydroxyvitamin D₃ and Non-hypercalcemic Analogs on Arginine Esterase Activity and 1α-hydroxylase mRNA Expression in Canine Prostate Tissue Explants and Primary Cultures.
   Principal Investigator: Dr. N Inpanbutr
   Source: The Canine Research Funds
   Co-investigators: Drs. CC Capen, T. Kaewsakhorn
3. Molecular Cloning and mRNA Expression of Equine Calbindin D-9k, Calbindin D-28k, Epithelial Calcium Channel 1, and Calcium-ATPase.
   Principal Investigator: Dr. Ramiro E. Toribio
   Co-Investigators: Drs. N Inpanbutr, TJ Rosol , CW Kohn
   Source: The Equine Research Funds
4. Effects of 1,25-Dihydroxyvitamin D₃ and Non-Hypercalcemic Analog EB 1089 on Cell Growth, Vitamin D Receptor (VDR) secretion and VDR mRNA Expression in the Canine Prostate Primary Cultures.
   Principal Investigator: Dr. N. Inpanbutr
   Co-investigators: Drs. CC Capen, T Kaewsakhorn
   Source: The Canine Research Funds

Funded Teaching Programs

1. Faculty Collaboration Grants, Title: Introduction to Veterinary Anatomy: Source: TELR (7/2003)
2. Web Base Program Development of Selected Surgical Procedures: Anatomy and Complete Illustrated Description of Anatomically-Challenging Procedures. Funded by: The OSU Alumni Association (9/2003)