OBJECTIVETo study the effects of different dietary fatty acid on the expression of nuclear receptor genes in the breast cancer of rats.

METHODSFifty-day-old female Sprague-Dawley rats were fed on eight different diets containing following fatty acids: saturated fatty acid (SFA); monounsaturated fatty acid (MUFA); n-6 polyunsaturated fatty acid (PUFA); n-3 PUFA; 1:1 n-6/n-3; 5:1 n-6/n-3; 10:1 n-6/n-3; 1:2:1 S/M/P (n-6/n-3 at 1:1). The rats were given a single intraperitoneal injection of methyl-nitrosourea (MNU) at 50 mg/kg body weight to establish the rat model of mammary carcinogenesis, the ultrastructure changes of mammary gland cells in rats were observed by transmission electron microscope, the cell proliferation activity was detected by BrdU-labeled immunocytochemistry, and the expression of PPARbeta and PPARgamma mRNA were assayed by RT-PCR.

RESULTSThere was no breast cancer occurring in control groups and the MNU-treated n-3 PUFA group, and the ultrastructure and proliferation activity of mammary gland cells in these groups were normal. In contrast, there appeared obvious marker of adenocarcinomas in mammary gland cells of MNU-induced breast cancer, and a high cell proliferation activity was found in tumor growth-enhancing groups (SFA, MUFA, n-6 PUFA, 5:1 n-6/n-3, 10:1 n-6/n-3 and S/M/P, 21% - 22% of BrdU-labeled cells), while a low cell proliferation activity was detected in rats fed with 1:1 n-6/n-3 diet (13% of BrdU-labeled cells, P < 0.05). Moreover, peroxisome proliferator-activated receptors (PPARs), as important nuclear receptor genes of relating lipid metabolism, the expressions of PPARbeta and PPARgamma mRNA were significantly up-regulated in mammary adipose tissues of MNU-induced breast cancer as compared with the control groups, but the expression levels of peroxisome proliferator-activated receptors (PPARs) in rats fed with 1:1 n-6/n-3 group were lowest (P < 0.05).

CONCLUSIONThe different dietary fatty acid compositions should diversely adjust the expression of PPARs gene in rats, which maybe have an important role in affecting incidence of breast cancer.

Animals ; Fatty Acids ; pharmacology ; Fatty Acids, Omega-3 ; pharmacology ; Fatty Acids, Omega-6 ; pharmacology ; Fatty Acids, Unsaturated ; pharmacology ; Female ; Gene Expression ; Gene Expression Regulation, Neoplastic ; Mammary Neoplasms, Experimental ; genetics ; PPAR gamma ; genetics ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley

The relationship between omega-3 polyunsaturated fatty acids (PUFAs) and violent-aggressive behavior has been payed attention since 1980s. Their correlation was explored by many epidemiological investigations, and the effect of PUFAs on prevention or reduction of violent-aggressive behavior in different groups were also affirmed by some intervention studies. This article summarized the previous studies and reviewed the history of epidemiological or intervention studies on PUFAs and its relationship with violent-aggressive behavior. It also presented the possible influencing factors in these studies and possible mechanisms.
Aggression ; Animals ; Dietary Fats, Unsaturated/pharmacology* ; Dietary Supplements ; Docosahexaenoic Acids/pharmacology* ; Eicosapentaenoic Acid/pharmacology* ; Fatty Acids, Omega-3/pharmacology* ; Fatty Acids, Omega-6/pharmacology* ; Fishes ; Folic Acid/metabolism* ; Humans ; Hydroxyindoleacetic Acid/metabolism* ; Norepinephrine/metabolism* ; Risk Factors ; Serotonin/metabolism* ; Violence/prevention & control*

OBJECTIVETo investigate the effects of polyunsaturated fatty acids (PUFA) &omega;-3 and &omega;-6, and their middle metabolites PGE2 and PGE3 on angiogenesis formation of gastric cancer, and to explore associated mechanism.

METHODSThe effects of &omega;-3, &omega;-6, PGE2, PGE3 on the proliferation and migration of human umbilical vein endothelial cell (HUVEC) were measured by proliferation and migration assay respectively. The angiogenesis assay in vivo was used to measure the effects of &omega;-3, &omega;-6, PGE2 and PGE3 on neovascularization. In all the assays, groups without &omega;-3, &omega;-6, PGE2 and PGE3 were designed as the control.

RESULTSWith the increased concentration of &omega;-6 from 1 μmol/L to 10 μmol/L, the proliferation ability of HUVECs enhanced, and the number of migration cells also increased from 28.2±3.0 to 32.8±2.1, which was higher than control group (21.2±3.2) respectively (both P<0.05). With the increased concentration of &omega;-3 from 1 μmol/L to 10 μmol/L, the proliferation ability of HUVECs was inhibited, and the number of migration cells decreased from 15.8±2.0 to 11.0±2.1, which was lower than control group (22.1±3.0) respectively (both P<0.05). In the angiogenesis assay, compared with control group (standard number: 43 721±4 654), the angiogenesis ability of HUVECs was significantly enhanced by &omega;-6 in concentration-dependent manner (1 μmol/L group: 63 238±4 795, 10 μmol/L group: 78 166±6 123, all P<0.01). Meanwhile, with the increased concentration of &omega;-3 from 1 μmol/L to 10 μmol/L, the angiogenesis ability was significantly decreased from 30 129±3 102 to 20 012±1 541(all P<0.01). The proliferation and migration ability of HUVECs were significantly promoted by &omega;-6 metabolites PGE2 (P<0.05) in a concentration-dependent manner. In contrast, &omega;-3 metabolites PGE3 significantly inhibited the proliferation and migration ability of HUVECs in a concentration-dependent manner (all P<0.05). After rofecoxib (a COX-2 specific inhibitor) inhibited the expression of COX-2, the expression level of PGE2 was significantly decreased in a dose-dependent manner. In co-culture system, whose gastric cancer cells expressed positive COX-2, &omega;-6 could increase angiogenesis of gastric cancer cells(P<0.01), but &omega;-3 could inhibit such angiogenesis(P<0.01). In co-culture system, whose gastric cancer cells did not express COX-2, &omega;-3 could inhibit the angiogenesis of gastric cancer cells (P<0.05), but &omega;-6 had no effect on angiogenesis.

CONCLUSIONSThe PUFA &omega;-6 can enhance the angiogenesis via the promotion of proliferation and migration of HUVECs, and COX-2 and PGE2 may play an important role in this process, whereas, the &omega;-3 can inhibit the angiogenesis through its middle metabolites PGE3 to inhibit the proliferation and migration of HUVECs. Results of this experiment may provide a new approach to inhibit and prevent the spread of gastric cancer.

Alprostadil ; analogs & derivatives ; pharmacology ; Angiogenesis Inducing Agents ; metabolism ; pharmacology ; Angiogenesis Inhibitors ; pharmacology ; Cell Count ; methods ; Cell Line, Tumor ; drug effects ; physiology ; Cell Migration Assays ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Coculture Techniques ; Cyclooxygenase 2 ; pharmacology ; Dinoprostone ; metabolism ; pharmacology ; Fatty Acids, Omega-3 ; pharmacology ; Fatty Acids, Omega-6 ; metabolism ; pharmacology ; Fatty Acids, Unsaturated ; pharmacology ; Human Umbilical Vein Endothelial Cells ; drug effects ; physiology ; Humans ; Lactones ; pharmacology ; Neovascularization, Pathologic ; physiopathology ; Stomach Neoplasms ; physiopathology ; Sulfones ; pharmacology