Source: OHIO STATE UNIVERSITY submitted to
FATTY ACID EFFECTS ON COX-2 DEPENDENT PROSTATE CANCER
 
PROJECT DIRECTOR: Failla, M.
 
PERFORMING ORGANIZATION
COLLEGE OF HUMAN ECOLOGY
OHIO STATE UNIVERSITY
WOOSTER,OH 44691
 
NON TECHNICAL SUMMARY: Dietary fatty acids may contribute to the progression of prostate cancer This project tests the abiltiy of dietary fatty acids to alter eicosanoid synthesis and contribute to carcinogenesis in a mouse model of prostate cancer.
 
OBJECTIVES: Dietary fat intake has been implicated in the progression of several major epithelial cancers including cancers of the breast, colon, and prostate. One of the mechanisms by which dietary fat has been proposed to influence carcinogenesis is through changing the profile of membrane fatty acids available for prostaglandin (PG) synthesis by the cyclooxygenase (COX) enzymes COX-1 and COX-2. Prostaglandins derived from arachidonic acid, such as PGE2, have been shown to induce cellular proliferation, inhibit apoptosis, and increase the expression of genes related to invasion and metastasis including matrix metalloproteases (MMP), e-cadherin and vascular endothelial growth factor (VEGF). Prostaglandins synthesized from n 3 fatty acids do not produce these effects and may actually inhibit carcinogenesis. Prostaglandins have been implicated in the progression of prostate cancer in animal and cell culture experiments, and it was recently reported that COX-2 is overexpressed in human prostate cancers. We have developed a transgenic mouse model (PB.COX2) in which the COX-2 enzyme is overexpressed specifically in the prostatic lobes of the mouse. This project will test the hypothesis that changes in the amount and type of dietary fatty acids fed to PB.COX2 mice will influence the expression of genes known to be involved in carcinogenesis. The overall goal of this project is to determine how diet induced changes in prostaglandin synthesis influence processes involve in prostate carcinogenesis. These studies are relevant to our ongoing prevention research, which is focused on the interaction of environmental factors with molecular mechanisms of carcinogenesis. The results of this research could lead to clinical trials which will enable us to make more mechanistically based recommendations regarding the consumption of dietary fat.
 
APPROACH: Specific Aim #1: Do type or quantity of dietary fatty acids alter prostaglandin (or other eicosanoid) levels in the prostates of PB.COX2 transgenic mice? Diets containing high levels of n-6 polyunsaturated fatty acids (n-6 PUFA), n-3 PUFA, monounsaturated (MUFA) or saturated fatty acids (SFA) will be fed to PB.COX2 mice for a period of four weeks with or without the addition of the COX-2 inhibitor celecoxib. The dorsal and ventral prostatic lobes will be removed and flash frozen in liquid nitrogen. The level and type of prostatic eicosanoids (including prostaglandins, HETEs, HODEs, etc.) will be determined by tandem mass spectrometry (LC/MS/MS). Specific Aim #2: Do type and quantity of dietary fatty acids alter cellular proliferation, apoptosis, and the regulation of genes involved in invasion and angiogenesis in a prostaglandin-dependent manner in the prostates of PB.COX2 transgenic mice? The diets from Aim #1 will be fed to PB.COX2 mice for a period of four weeks with or without the addition of the COX-2 inhibitor celecoxib. Half of the mice from each treatment group will be injected with BrdU prior to necropsy and the entire urogenital tract, including the dorsal-lateral and ventral prostatic lobes, will be removed and fixed in formalin. Proliferation will be assessed by immunohistochemical staining for BrdU incorporation and cyclin D. Markers of apoptosis (TUNEL), and proteins involved in invasion (MMPs) and angiogenesis (VEGF) will also be assessed. The other half of the mice in each treatment group will have the ventral and dorsal prostatic lobes removed and fixed in ethanol. These tissues will be used to isolate specific prostate epithelial cells by laser-capture microdissection for isolation of RNA. The RNA from these cells will be analyzed for the expression of genes related to proliferation, apoptosis, and invasion using real-time quantitative RT-PCR. Specific Aim #3: Which prostaglandin receptors are involved in prostaglandin-regulated cell proliferation, apoptosis and gene expression of MMP and VEGF in human prostate cell lines? Normal prostate cells (PrEC) and the prostate cancer cell lines PC-3, Du-145, and LNCaP will be characterized for the expression of prostaglandin receptors DP, EP1, EP2, EP3, EP4, and, FP and the nuclear receptor PPAR gamma by western analysis and RT-PCR. These cell lines will then be treated with the appropriate specific agonists and antagonists of the prostaglandin cell surface receptors. The effect of activation of these specific prostaglandin receptors on cell proliferation, apoptosis, and the expression of Bcl-2, MMPs, and VEGF will be assessed.
 
CRIS NUMBER: 0200285 SUBFILE: CRIS
PROJECT NUMBER: OHO01090 SPONSOR AGENCY: NIFA
PROJECT TYPE: HATCH PROJECT STATUS: TERMINATED MULTI-STATE PROJECT NUMBER: (N/A)
START DATE: May 1, 2004 TERMINATION DATE: Sep 30, 2008

GRANT PROGRAM: (N/A)
GRANT PROGRAM AREA: (N/A)

CLASSIFICATION
Knowledge Area (KA)Subject (S)Science (F)Objective (G)Percent
702384010105.150%
702384010305.120%
702384010405.130%

CLASSIFICATION HEADINGS
KA702 - Requirements and Function of Nutrients and Other Food Components
S3840 - Laboratory animals
F1030 - Cellular biology
F1010 - Nutrition and metabolism
F1040 - Molecular biology
G5.1 - Ensure Access to Nutritious Food


RESEARCH EFFORT CATEGORIES
BASIC 100%
APPLIED (N/A)%
DEVELOPMENTAL (N/A)%

KEYWORDS: dietary fatty acids; fish oil; fatty acids; prostate gland; cancer; nutrient disease relations; prostaglandins; eicosenoic acid; transgenic animals; mice; cyclo oxygenase; laboratory animals; nutrient function; human diseases; cell biology; molecular biology; cell physiology; membrane lipids; carcinogenesis; enzyme inhibitors; disease treatment; disease prevention; receptors; cell lines; genetics; signal transduction; metabolic pathways; human metabolism

PROGRESS: Jan 1, 2007 TO Dec 31, 2007
OUTPUTS: Prostate and bladder cancers are significant health problems. Identification of new molecular targets may provide effective strategies to reduce the development and progression of these two diseases. Cyclooxygenase enzymes, COX-1 and COX-2, catalyze a rate limiting step in the synthesis of prostaglandins from arachidonic acid. Dietary fatty acids have been shown to regulate prostaglandin signaling pathways and could therefore either negatively or positively regulate prostate and bladder tumorigenesis depending on the profile of fatty acid intake. Overexpression COX-2 and prostaglandin E2 (PGE2) have been demonstrated to play a significant role in the tumorigenesis of several human cancers. Inconsistent and controversial reports on the expression and activity of COX-2 in prostate cancer raised the question of whether COX-2 plays a pivotal role in prostate carcinogenesis. In contrast, there is more consistent support for a positive link between COX-2 overexpression and bladder carcinogenesis. However, the exact role of COX-2 overexpression and how changes in gene regulation alter in urinary bladder carcinogenesis has not been defined. We first examined the effects of COX-2 inhibition on prostate tumorigenesis in the transgenic adenocarcinoma mouse prostate (TRAMP) model by either feeding TRAMP mice a diet containing non-steroidal anti-inflammatory drugs (NSAIDs) or by genetic disruption of the expression of the COX-2 gene in TRAMP mice. Our results demonstrate that neither NSAIDs nor genetic disruption of COX-2 inhibited tumorigenesis of TRAMP prostate. Interestingly, we found that the expression of COX-1 and COX-2 mRNA, protein, and activity (ability to synthesize PGE2) dramatically decreased during TRAMP prostate carcinogenesis. We also used a gene expression array analysis to determine the effects of COX-2 overexpression on gene expression profile in urinary bladder of a COX-2 overexpression transgenic mouse model (BK5.COX-2). Our results revealed that genes associated with Immune/Stress Response and Cell Cycle/Proliferation systems were significantly overexpressed in the BK5.COX-2 mouse bladders. Upregulated Cell Cycle/Proliferation genes included growth factors (Ereg and IGF-1) and cell cycle genes (Mki67, Cdc2a, and Top2a). Relevant downregulated genes included three transforming growth factor beta related genes (Tgfb2, Tgfb3, Tgfbi), and the anti-angiogenic gene thrombospondin 2 (Thbs2). The growth factor epiregulin was the most highly induced gene among those validated by qRT-PCR. We further demonstrated that epiregulin mRNA was directly induced by PGE2 treatment in the wild type mouse bladders. In addition, epiregulin increased cell proliferation and activated MAPK/Erk activity in bladder cancer cells. In summary, our results suggest that COX-2 may not play a significant role during prostate carcinogenesis in the prostate TRAMP model. However, overexpression of COX-2 may play a pivotal role in murine bladder carcinogenesis. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

IMPACT: 2007-01-01 TO 2007-12-31 These new data show that the enzymatic synthesis of prostaglandins may have a pivotal role in bladder carcinogenesis by regulating the expression of specific patterns of gene expression. Because dietary fatty acids play an important role in the modulation of prostaglandin synthesis, they may affect bladder carcinogenesis. Whether dietary intervention with the anti-inflammatory activity of fish oil inhibits bladder carcinogenesis in BK5.COX2 mouse model warrants evaluation.

PUBLICATION INFORMATION: 2007-01-01 TO 2007-12-31
Wang X, Colby JK, Yang P, Fischer SM, Newman, RA, Klein RD. Prostate tumorigenesis in TRAMP mice is not inhibited by NSAIDs or genetic disruption of cyclooxygenase-2 expression. Carcinogenesis. 2008 Jan;29(1):120-8. Epub 2007 Oct 17.

PROJECT CONTACT INFORMATION
NAME: Failla, M.
PHONE: 614-292-4485
FAX: (N/A)