This is not prostate cancer specific information, but I don't
currently see any reason, why it couldn't apply also for PC.

Cancer cells make their energy throughout the main body of the cell,
rather than in the mitochondria. This process, glycolysis, is
inefficient and uses up vast amounts of sugar. Until now it had been
assumed that cancer cells used glycolysis because their mitochondria
were irreparably damaged. However, Dr. Evangelos Michelakis of the
University of Alberta in Edmonton, Canada, and his colleagues
tested Dichloroacetic acid (DCA) on human lung, breast, brain cancer
cells and healthy cells cultured outside the body, and found that DCA
reawakened the mitochondria in cancer cells. The cancer cells then
withered and died. The healthy cells were unaffected. Tumours in rats
deliberately infected with human cancer also shrank drastically when
they were fed DCA-laced water for several weeks.

Although there is still a very long way to go, and financing
the research of an unpatentable(?) drug could cause a problem, it
certainly looks interesting, IMHO.

The study is

Bonnet S, Archer SL, Allalunis-Turner J, Haromy A, Beaulieu C,
Thompson R, Lee CT, Lopaschuk GD, Puttagunta L, Bonnet S, Harry G,
Hashimoto K, Porter CJ, Andrade MA, Thebaud B, Michelakis ED.
A mitochondria-k(+) channel axis is suppressed in cancer and its
normalization promotes apoptosis and inhibits cancer growth.
Cancer Cell. 2007 Jan;11(1):37-51.
PMID: 17222789 [PubMed - in process]
<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra
ctPlus&list_uids=17222789>
<http://www.cancercell.org/content/article/abstract?uid=PIIS1535610806003722>

University of Alberta news releases:

Small molecule offers big hope against cancer
University of Alberta, News release January 16, 2007
<http://www.expressnews.ualberta.ca/article.cfm?id=8153>

Small molecule offers big hope against cancer- Information and Videos
Videos of Dr.Michelakis' interview.
University of Alberta, Faculty of Medicine & Dentistry, News release
January 17, 2007
<http://www.med.ualberta.ca/news-publications/article.cfm?id=123>

News articles:

The Why Files: Small molecule could be a big cancer fighter
<http://whyfiles.org/shorties/225cancer_drug/>

Cheap, safe drug kills most cancers
New Scientist, 17 January 2007
<http://www.newscientist.com/article/dn10971-cheap-safe-drug-kills-most-cancers.html>

Editorial: No patent? No cancer drug development
New Scientist, 20 January 2007
<http://www.newscientist.com/channel/opinion/mg19325873.000-editorial-no-patent-n
o-cancer-drug-development.html>

Small Molecule Offers Big Hope Against Cancer
Medical News Today, 19 January 2007
<http://www.medicalnewstoday.com/medicalnews.php?newsid=60958>

Small Molecule Offers Big Hope Against Cancer
ScienceDaily, January 17, 2007
<http://www.sciencedaily.com/releases/2007/01/070116134001.htm>

Cramping tumours
The Economist, Jan 18th 2007
<http://www.economist.com/science/displaystory.cfm?story_id=8548706>

Small molecule offers big hope against cancer
physorg.com, January 16, 2007
<http://www.physorg.com/news88194392.html>