The protein also assists in the retention of vitamin E in prostate cancer cells and increases the effect of vitamin E in limiting the proliferation of cancer cells, the researchers found.
The researchers, led by ShuYuan Yeh, assistant professor of urology and pathology at the University of Rochester Medical Center, are the first to describe the role of a protein known as alpha tocopherol associated protein or TAP in prostate cancer. Expression levels of TAP are significantly lower in prostate cancer than in a normal prostate, the researchers found. High expression of TAP protein in prostate cells may have a physiological role in normal prostate development and vitamin E-related functions, Yeh said.
The findings are reported in the Nov. 1 issue of the journal Cancer Research.
Restoring TAP levels in men with prostate cancer could produce a therapeutic effect, but Yeh described the process as "difficult and limited." She and her research team are investigating whether specific substances can increase the expression of TAP.
While TAP itself someday could become an effective avenue of treatment for prostate cancer, it has immediate potential as a new prognostic marker.
"If research continues to show the important role of TAP, we could use TAP expression levels to better assess and predict the aggressiveness of the cancer," said urologist Edward M. Messing, M.D., chair of Urology at the University of Rochester Medical Center. "We may be able to use TAP levels to predict whether a patient will respond to treatment."
TAP is a binding protein that performs important cellular functions. In the liver, for example, TAP plays a role in regulating the synthesis of cholesterol.
Yeh and her research team found high levels of TAP in epithelial cells of normal prostate tissu
'"/>
Contact: Michael Wentzel
michael_wentzel@urmc.rochester.edu
585-275-1309
University of Rochester Medical Center
1-Nov-2005