Tumor growth reduction is regulated at the gene level in Walker 256 tumor-bearing rats supplemented with fish oil rich in EPA and DHA

Abstract

We investigated the effect of fish oil (FO) supplementation on tumor growth, cyclooxygenase 2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARγ), and RelA gene and protein expression in Walker 256 tumor-bearing rats. Male Wistar rats (70 days old) were fed with regular chow (group W) or chow supplemented with 1 g/kg body weight FO daily (group WFO) until they reached 100 days of age. Both groups were then inoculated with a suspension of Walker 256 ascitic tumor cells (3×107 cells/mL). After 14 days the rats were killed, total RNA was isolated from the tumor tissue, and relative mRNA expression was measured using the 2-ΔΔCT method. FO significantly decreased tumor growth (W=13.18±1.58 vs WFO=5.40±0.88 g, P<0.05). FO supplementation also resulted in a significant decrease in COX-2 (W=100.1±1.62 vs WFO=59.39±5.53, P<0.001) and PPARγ (W=100.4±1.04 vs WFO=88.22±1.46, P<0.05) protein expression. Relative mRNA expression was W=1.06±0.022 vs WFO=0.31±0.04 (P<0.001) for COX-2, W=1.08±0.02 vs WFO=0.52±0.08 (P<0.001) for PPARγ, and W=1.04±0.02 vs WFO=0.82±0.04 (P<0.05) for RelA. FO reduced tumor growth by attenuating inflammatory gene expression associated with carcinogenesis.

Effects of Chinese Medicine Tong xinluo on Diabetic Nephropathy via Inhibiting TGF-β1-Induced Epithelial-to-Mesenchymal Transition

“…Each sample was reverse transcribed into cDNA using SuperScript II Reverse Transcriptase (Invitrogen). Gene expression was quantified by means of the comparative Ct method (ΔΔCt) and the relative quantification (RQ) was calculated as 2 −ΔΔCt [ 21 – 23 ]. Relative mRNA levels of E-CA, α -SMA, smad3, smad7, Col IV, and FN were examined and normalized to β -actin mRNA.…”

α-Linolenic Fatty Acid Supplementation Decreases Tumor Growth and Cachexia Parameters in Walker 256 Tumor-Bearing Rats

“…n-3PUFA, mainly EPA and DHA, have anticancer effects and promote the action of other anticarcinogenic agents (7). In fish oil-supplemented Walker 256 tumor-bearing rats was observed attenuation of cancer cachexia syndrome, reduction of tumor growth and increased life span (3), increased tumor lipid peroxidation (8), reduced ex vivo proliferation of tumor cells and lower tumor COX-2 expression (5) and mRNA expression (9), reduction of TNF-a cytokine production by macrophages (10) and lymphocyte proliferation (11). An important issue to address by the lack of information is a question that hovers in nutrition area; a-linolenic fatty acid (ALA) can cause the same effect as their metabolites, EPA and DHA.…”

Walker-256 Tumor: Experimental Model, Implantation Sites and Number of Cells for Ascitic and Solid Tumor Development

“…Subsequently, the technique was improved and the tumor cell line is easily implantable, specific for mice and grows rapidly in the host animal. The cells are maintained in the laboratory by means of weekly passages into intraperitoneal cavity of rats, when necessary the solid tumor is induced by subcutaneous or muscle and become palpable about four days post-implant and can grow to a mean diameter of 20-30 mm within 8 days 4,13,23,27,52 .…”

“…However, it case diverse collateral effects and are not efficient in complete remission of tumor. Therefore, several studies are developed searching for new substances that can substitute the conventional method 4,5,6,7,8,9,10,11 . Thus, it is necessary to use experimental models that corresponds more to the reality of individuals affected by this disease.…”