Effect of obese and lean Zucker rat sera on human and rat prostate cancer cells: implications in obesity-related prostate tumor biology.
OBJECTIVE
Several reports have demonstrated the effects of obesity on prostate cancer. Also several reports have linked expression of vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor (FGF-2) to prostate cancer aggressiveness. The objective of this study was to determine whether a difference exists between lean and obese Zucker rat sera on proliferation prostate cancer cell lines, as well as to examine the differences in FGF-2 and VEGF concentrations.


METHODS
Ten-week-old female obese and lean Zucker rat sera were subjected to charcoal stripping and tested for the proliferation of human LNCaP and rat AT3B-1 prostate cancer cells. An acetonitrile extract of the charcoal used to strip the sera was also tested for mitogenicity. VEGF and FGF-2 concentrations were determined by enzyme-linked immunosorbent assay.


RESULTS
Both unstripped and charcoal-stripped obese rat sera had a greater mitogenic effect than did the lean sera on the LNCaP cell line. Charcoal stripping of both obese and lean sera reduced the mitogenic effect on the AT3B-1 cell line. The acetonitrile extract of the charcoal used to strip the sera was unable to recover this proliferative effect. The concentration of VEGF was greater in the obese serum than in the lean serum, and charcoal stripping reduced the concentrations of both FGF-2 and VEGF.


CONCLUSIONS
The finding of greater VEGF in obese rat sera, as well as greater mitogenic responses on human prostate cancer cells in vitro, suggests this as one of the many possible mechanisms involved in obesity-related prostate cancer biology.
Lamarre
Neil S
NS
Department of Urology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
Ruggieri
Michael R
MR
Braverman
Alan S
AS
Gerstein
Matthew I
MI
Mydlo
Jack H
JH
D000818:Animals; D049109:Cell Proliferation; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications / Q000473:pathology; D011467:Prostate / Q000166:cytology*; D011471:Prostatic Neoplasms / Q000150:complications / Q000473:pathology; D051381:Rats; D011924:Rats, Zucker; D044967:Serum / Q000737:chemistry / Q000502:physiology*; D014407:Tumor Cells, Cultured; D042442:Vascular Endothelial Growth Factors / Q000032:analysis
D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2