Omega-3 fatty acids inhibit tumor growth in a rat model of bladder cancer

Preclinical models of bladder cancer: BBN and beyond

Preclinical modelling is a crucial component of advancing the understanding of cancer biology and therapeutic development. Several models exist for understanding the pathobiology of bladder cancer and evaluating therapeutics. N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced bladder cancer is a commonly used model that recapitulates many of the features of human disease. Particularly in mice, BBN is a preferred laboratory model owing to a high level of reproducibility, high genetic fidelity to the human condition, and its relative ease of use. However, important aspects of the model are often overlooked in laboratory studies. Moreover, the advent of new models has yielded a variety of methodologies that complement the use of BBN. Toxicokinetics, histopathology, molecular genetics and sex can differ between available models and are important factors to consider in bladder cancer modelling.

Omega-3 Polyunsaturated Fatty Acids Alleviate Intestinal Barrier Dysfunction in Obstructive Jaundice Rats

Obstructive jaundice (OJ) can cause multiple pathophysiological consequences including intestinal barrier dysfunction. Omega-3 has been indicated to have a promising therapeutic effect on OJ. This study aimed to further investigate the functions of omega-3 on OJ-induced intestinal injury. A rat OJ model was established by bile duct ligation with or without omega-3 administration. ELISA was utilized for measuring serum levels of inflammatory cytokines. Hematoxylin-eosin staining and TUNEL staining were employed for detecting the morphological changes and cell apoptosis in rat intestine. Western blotting was utilized for evaluating expression of tight junction proteins in the intestinal tissues. Omgea-3 offset the reduction in body weight of OJ rats. Omega-3 alleviated inflammatory response, pathological damages and cell apoptosis in the intestine of OJ rats. Additionally, omega-3 enhanced levels of tight junction proteins in the intestinal tissues of OJ rats. Omega-3 ameliorates OJ-triggered impairment of intestinal barrier function in rats.

FADS2 function at the major cancer hotspot 11q13 locus alters fatty acid metabolism in cancer

Dysregulation of fatty acid metabolism and de novo lipogenesis is a key driver of several cancer types through highly unsaturated fatty acid (HUFA) signaling precursors such as arachidonic acid. The human chromosome 11q13 locus has long been established as the most frequently amplified in a variety of human cancers. The fatty acid desaturase genes (FADS1, FADS2 and FADS3) responsible for HUFA biosynthesis localize to the 11q12-13.1 region. FADS2 activity is promiscuous, catalyzing biosynthesis of several unsaturated fatty acids by Δ6, Δ8, and Δ4 desaturation. Our main aim here is to review known and putative consequences of FADS2 dysregulation due to effects on the 11q13 locus potentially driving various cancer types. FADS2 silencing causes synthesis of sciadonic acid (5Z,11Z,14Z-20:3) in MCF7 cells and breast cancer in vivo. 5Z,11Z,14Z-20:3 is structurally identical to arachidonic acid (5Z,8Z,11Z,14Z-20:4) except it lacks the internal Δ8 double bond required for prostaglandin and leukotriene synthesis, among other eicosanoids. Palmitic acid has substrate specificity for both SCD and FADS2. Melanoma, prostate, liver and lung cancer cells insensitive to SCD inhibition show increased FADS2 activity and sapienic acid biosynthesis. Elevated serum mead acid levels found in hepatocellular carcinoma patients suggest an unsatisfied demand for arachidonic acid. FADS2 circular RNAs are at high levels in colorectal and lung cancer tissues. FADS2 circular RNAs are associated with shorter overall survival in colorectal cancer patients. The evidence thusfar supports an effort for future research on the role of FADS2 as a tumor suppressor in a range of neoplastic disorders.

Diet quality, common genetic polymorphisms, and bladder cancer risk in a New England population-based study

PURPOSE

We examined the interaction between common genetic bladder cancer variants, diet quality, and bladder cancer risk in a population-based case-control study conducted in New England.

METHODS

At the time of enrollment, 806 bladder cancer cases and 974 controls provided a DNA sample and completed a diet history questionnaire. Diet quality was assessed using the 2010 Alternate Healthy Eating Index (AHEI-2010) score. Single nucleotide polymorphisms (SNPs) reported in genome-wide association studies to be associated with bladder cancer risk were combined into a polygenic risk score and also examined individually for interaction with the AHEI-2010. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression.

RESULTS

A 1-standard deviation increase in polygenic risk score was associated with higher bladder cancer risk (OR, 1.34; 95% CI 1.21-1.49). Adherence to the AHEI-2010 was not associated with bladder cancer risk (OR, 0.99; 95% CI 0.98-1.00) and the polygenic risk score did not appear to modify the association between the AHEI-2010 and bladder cancer risk. In single-SNP analyses, rs8102137 (bladder cancer risk allele, C) modified the association between the AHEI-2010 total score and bladder cancer risk, with the strongest evidence for the AHEI-2010 long chain fat guideline (OR for TT, 0.92; 95% CI 0.87-0.98; OR for CT, 1.02; 95% CI 0.96-1.08; OR for CC, 1.03; 95% CI 0.93-1.14; p for interaction, 0.02).

CONCLUSIONS

In conclusion, rs8102137 near the cyclin E1 gene ( CCNE1 ) may be involved in gene-diet interactions for bladder cancer risk.

Omega-3 polyunsaturated fatty acids: a modified approach for chemo-prevention of bladder cancer in a rat model and molecular studies of antineoplastic mechanisms

OBJECTIVES

To test the chemo-preventative effects of omega-3 against bladder cancer (BC) induction in a rat model and its potential antineoplastic mechanisms.

MATERIAL AND METHODS

Ninety male Fisher rats were divided into three groups during a 22-week protocol: group 1 (control), group 2 (Placebo + N-butyl-N-4- hydroxybutyl nitrosamine (BBN) for induction of BC and group 3 received omega-3 (1200 mg/kg/day) + BBN. At the end, blood samples and bladder tissues were collected and checked for the presence of malignancy, markers of angiogenesis (VEGF relative gene expression), inflammation (IL-6), proliferation (KI-67 expressions), oxidative stress (serum MDA and serum SOD) and epigenetic control (miRNA-145 level).

RESULTS

At the end of the study, 60% and 86.6% rats survived in group 2 and 3 with significant weight loss among rats in group 2 when compared with other groups. In group 2, all rats developed visible bladder lesions of which five and 13 developed squamous cell carcinoma (SCC) and transitional cell carcinoma (TCC). In omega3-treated group, only one developed low grade SCC and one developed high grade non- invasive TCC. Bladders from omega-3-treated rats showed lower expression ofKI-67 (p < 0.05), VEGF (p < 0.001) and IL-6 (p < 0.001) and significant higher expression of mi-RNA (p < 0.001). Also, omega-3-treated group showed statistically significant lower MDA level (p < 0.001).

CONCLUSION

Omega-3 inhibits bladder tumor growth in the BBN-induced BC rat model, due to anti-inflammatory, antioxidant, anti-proliferative, and anti-angiogenic properties together with epigenetic control.

The Ω-3 fatty acid docosahexaenoic acid selectively induces apoptosis in tumor-derived cells and suppress tumor growth in gastric cancer

Despite current achievements and innovations in cancer treatment, conventional chemotherapy has several limitations, such as unsatisfactory long-term survival, cancer drug resistance and toxicity against non-tumoral cells. In the search for safer therapeutic alternatives, docosahexaenoic acid (DHA) has shown promising effects inhibiting tumor growth without significant side effects in several types of cancer, but in gastric cancer (GC) its effects have not been completely described. In this study, we characterized the effects of DHA in GC using in vivo and in vitro models. Among all of the evaluated Ω-3 and Ω-6 fatty acids, DHA showed the highest antiproliferative potency and selectivity against the GC-derived cell line AGS. 10-100 μM DHA decreased AGS cell viability in a concentration-dependent manner but had no effect on non-tumoral GES-1 cells. To evaluate if the effects of DHA were due to apoptosis induction, cells were stained with Annexin V-PI, observing that 75 and 100 μM DHA increased apoptosis in AGS, but not in GES-1 cells. Additionally, levels of several proapoptotic and antiapoptotic regulators were assessed by qPCR, western blot and activity assays, showing similar results. In order to evaluate DHA efficacy in vivo, xenografts in an immunodeficient mouse model (BALB/cNOD-SCID) were used. In these experiments, DHA treatment for six weeks consistently reduced subcutaneous tumor size, ascitic fluid volume and liver metastasis. In summary, we found that DHA has a selective antiproliferative effect on GC, being this effect driven by apoptosis induction. Our investigation provides promising features for DHA as potential therapeutic agent in GC.

Chemopreventive Potential of Myrtenal against Nitrosamine-Initiated, Radiation-Promoted Rat Bladder Carcinogenesis

The present study was undertaken to evaluate the chemopreventive activity of myrtenal, a natural monoterpene, against bladder carcinoma in rats induced with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) and promoted with γ-ionizing radiation (γ-IRR) as well as to assess the involvement of inflammation, apoptosis and oxidative damage in tumor development. Histopathological examination of rat bladder revealed the presence of noninvasive papillary transitional cell carcinoma (Grade 2) in sections from BBN group indicating the credibility of the applied carcinogenesis model. Myrtenal treatment caused improvement in urinary bladder mucosa with cells more likely in Grade 1. Administration of myrtenal to BBN-treated rats exhibited downregulation in the expressions of COX-2, NF-kB and STAT-3 associated with suppression of inflammatory cytokines levels of TNF-α and IL-6 as well as biomarkers of oxidative damage (MDA & NO). In addition, myrtenal treatment caused a significant increase in caspase-3 activity and Bax/Bcl-2 ratio. Data obtained suggested that the anti-inflammatory effect and the induction of apoptosis contributed largely to the beneficial antitumor effects of myrtenal in rats with BBN/γ-IRR-induced bladder carcinoma. Present findings, in addition to benefits described in other pathologies, indicated myrtenal as a potential adjuvant natural compound for the prevention of tumor progression of bladder cancer.

Preventive effect of pomegranate juice against chemically induced bladder cancer: An experimental study

OBJECTIVES

Pomegranate juice (PJ) is rich in important compounds with anti-cancer activities. This study aims to investigate the preventive effect of pomegranate juice (PJ) against bladder cancer (BC).

METHODS

Eighty male Sprague Dawley rats were randomly classified into 4 equal groups: (1) Normal controls; (2) PJ group: supplied by PJ for 12 weeks; (3) Cancer-induced group: intake 0.05% v/v N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) for 8 weeks; (4) Cancer-prevented group: BBN + PJ. After 12 weeks, all rats were sacrificed and their urinary bladder tissues were subjected to histopathological and immunohistochemical (p53) examinations, expression of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), hypoxia-inducible factor 1 (HIF-1) and the tumor protein p53 (TP53) and analysis of oxidative stress markers.

RESULTS

The development of BC was: 0/20 (0%) in normal, PJ and cancer-prevented groups and 20/20 (100%) in cancer-induced group. Significant neoplastic lesions were observed in cancer-induced group. Mild preneoplastic alterations were noticed in 25% (5/20) of cancer-prevented group. p53 immunostaining were significantly elevated in the cancer-induced group, which was decreased in the cancer-prevented group. The relative expressions of IL-6, TNF-α, HIF-1 and TP53 were significantly lower in the cancer-prevented group compared to the cancer-treated group. Correction in the oxidative stress markers were also observed in the cancer-prevented group.

CONCLUSION

PJ possesses a promising inhibitory effect on BC development, probably due to its anti-oxidant and anti-inflammatory properties.

Lichen sclerosus: the role of oxidative stress in the pathogenesis of the disease and its possible transformation into carcinoma

Lichen sclerosus (LS) is an autoimmune chronic inflammatory disease usually involving the anogenital skin of both sexes; more rarely LS exclusively involves extragenital areas. As a chronic inflammatory disease, in most cases, LS evolves and progresses causing scleroatrophy of the skin or scars which may cause stenosis in the affected areas. A few LS patients are at risk of developing squamous cell carcinoma in their lifetime, but appropriate long-term treatment diminishes the possibility of a malignant evolution. Oxidative stress (OS) has been proven to play a role not only in the pathogenesis of LS, but also in the development and progression of the disease. OS, by causing DNA damage and lipid peroxidation, contributes directly to the possible malignant transformation of LS. Moreover, the increase in oxidative DNA damage is associated with mutations in tumor suppressor genes. Considering the role that OS plays in LS, therapeutic use of antioxidants appears to be rational and possible, in association with other treatments. Antioxidants would counteract the oxidative DNA damage, which is the most important factor for the progression of LS and its malignant transformation.

Bladder cancer extracellular vesicles drive tumorigenesis by inducing the unfolded protein response in endoplasmic reticulum of nonmalignant cells

The field cancerization effect has been proposed to explain bladder cancer's multifocal and recurrent nature, yet the mechanisms of this effect remain unknown. In this work, using cell biology, flow cytometry, and qPCR analyses, along with a xenograft mouse tumor model, we show that chronic exposure to tumor-derived extracellular vesicles (TEVs) results in the neoplastic transformation of nonmalignant human SV-HUC urothelial cells. Inhibition of EV uptake prevented this transformation. Transformed cells not only possessed several oncogenic properties, such as increased genome instability, loss of cell-cell contact inhibition, and invasiveness, but also displayed altered morphology and cell structures, such as an enlarged cytoplasm with disrupted endoplasmic reticulum (ER) alignment and the accumulation of smaller mitochondria. Exposure of SV-HUC cells to TEVs provoked the unfolded protein response in the endoplasmic reticulum (UPR^ER). Prolonged induction of UPR^ER signaling activated the survival branch of the UPR^ER pathway, in which cells had elevated expression of inositol-requiring enzyme 1 (IRE1), NF-κB, and the inflammatory cytokine leptin, and incurred loss of the pro-apoptotic protein C/EBP homologous protein (CHOP). More importantly, inhibition of ER stress by docosahexaenoic acid prevented TEV-induced transformation. We propose that TEVs promote malignant transformation of predisposed cells by inhibiting pro-apoptotic signals and activating tumor-promoting ER stress-induced unfolded protein response and inflammation. This study provides detailed insight into the mechanisms underlying the bladder cancer field effect and tumor recurrence.

Decreased Oleic Acid and Marine n - 3 Polyunsaturated Fatty Acids in Tunisian Patients with Urothelial Bladder Cancer

Fatty acids (FAs) are thought to impact carcinogenesis by affecting cell signaling. A case-control study including 250 patients with urothelial bladder cancer (UBC) and 250 controls was conducted. Plasma FAs composition was assessed using capillary gas chromatography. Associations of individual and classes of FAs with UBC were controlled for the main risk factors for UBC. Plasma FAs profile was different in patients compared to controls. Higher levels (third tertile vs. first tertile) in palmitic acid (PA) [multi-adjusted OR (95% CI), 1.83 (1.14-2.92)], and n - 6:n - 3 FA ratio [4.13 (2.38-7.16)] were associated with increased risk for UBC [multi-adjusted OR (95% CI), 1.83 (1.14-2.92)]. In contrast, higher levels (third tertile vs. first tertile) in oleic [0.54 (0.34-0.86)], dihomo-γ-linolenic (DGLA) [0.47 (0.29-0.74)], eicosapentaenoic (EPA) [0.32 (0.19-0.52)], and docosahexaenoic (DHA) acids [0.33 (0.20-0.53)] were associated with lower risk for UBC. Although the study design does not allow proving causality, the findings suggest a possible protective role of oleic acid and marine n - 3 polyunsaturated FAs (PUFAs) against bladder carcinogenesis.

Attenuation of choroidal neovascularization by dietary intake of ω-3 long-chain polyunsaturated fatty acids and lutein in mice

Dietary ω-3 long-chain polyunsaturated fatty acids (LCPUFAs) and lutein each protect against age-related macular degeneration (AMD). We here examined the effects of ω-3 LCPUFAs and lutein supplementation in a mouse model of AMD. Mice were assigned to four groups: (1) a control group fed an ω-3 LCPUFA-free diet, (2) a lutein group fed an ω-3 LCPUFA-free diet with oral administration of lutein, (3) an ω-3 group fed an ω-3 LCPUFA-supplemented diet, and (4) an ω-3 + lutein group fed an ω-3 LCPUFA-supplemented diet with oral administration of lutein. Mice were fed the defined diets beginning 2 weeks before, and received lutein with an oral gavage needle beginning 1 week before, induction of choroidal neovascularization (CNV) by laser photocoagulation. The area of CNV measured in choroidal flat-mount preparations was significantly reduced in mice fed ω-3 LCPUFAs or lutein compared with those in the control group, and it was reduced in an additive manner in those receiving both ω-3 LCPUFAs and lutein. The concentrations of various inflammatory mediators in the retina or choroid were reduced in mice fed ω-3 LCPUFAs or lutein, but no additive effect was apparent. The generation of reactive oxygen species (ROS) in chorioretinal lesions revealed by dihydroethidium staining as well as the expression of NADPH oxidase 4 (Nox4) in the retina revealed by immunohistofluorescence and immunoblot analyses were attenuated by ω-3 LCPUFAs and lutein in a synergistic manner. Our results thus show that dietary intake of ω-3 LCPUFAs and lutein attenuated CNV in an additive manner and in association with suppression of inflammatory mediator production, ROS generation, and Nox4 expression. Dietary supplementation with both ω-3 LCPUFAs and lutein warrants further study as a means to protect against AMD.

Chemopreventive and Chemotherapeutic Effects of Fish Oil derived Omega-3 Polyunsaturated Fatty Acids on Colon Carcinogenesis

Colorectal cancer is the third most common cause of cancer related death in the world. Multiple lines of evidence suggest that there is an association between consumption of dietary fat and colon cancer risk. Not only the amount but also the type and the ratio of fatty acids comprising dietary fats consumed have been implicated in the etiology and pathogenesis of colon cancer. Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been known to inhibit development of colon cancer by downregulating the expression of genes involved in colon carcinogenesis and also by altering the membrane lipid composition. Data from laboratory, epidemiological, and clinical studies substantiate the beneficial role of n-3 PUFAs in preventing colitis and subsequent development of colon cancer. In addition, recent studies suggest that some n-3 PUFAs can be effective as an adjuvant with chemotherapeutic agents and other natural anticancer compounds in the management of colon cancer. In this review, we discuss chemopreventive and therapeutic effects of fish oil derived long chain n-3 PUFAs, particularly EPA and DHA, with focus on synergetic effects of which they exert when combined with chemotherapeutic agents and other natural compounds.

Synergistic anticancer properties of docosahexaenoic acid and 5-fluorouracil through interference with energy metabolism and cell cycle arrest in human gastric cancer cell line AGS cells

AIM: To explore the synergistic effect of docosahexaenoic acid (DHA)/5-fluorouracil (5-FU) on the human gastric cancer cell line AGS and examine the underlying mechanism.

METHODS: AGS cells were cultured and treated with a series of concentrations of DHA and 5-FU alone or in combination for 24 and 48 h. To investigate the synergistic effect of DHA and 5-FU on AGS cells, the inhibition of cell proliferation was determined by MTT assay and cell morphology. Flow cytometric analysis was also used to assess cell cycle distribution, and the expression of mitochondrial electron transfer chain complexes (METCs) I, II and V in AGS cells was further determined by Western blot analysis.

RESULTS: DHA and 5-FU alone or in combination could markedly suppress the proliferation of AGS cells in a significant time and dose-dependent manner. DHA markedly strengthened the antiproliferative effect of 5-FU, decreasing the IC₅₀ by 3.56-2.15-fold in an apparent synergy. The morphological changes of the cells were characterized by shrinkage, cell membrane blebbing and decreased adherence. Cell cycle analysis showed a shift of cells into the G0/G1 phase from the S phase following treatment with DHA or 5-FU (G0/G1 phase: 30.04% ± 1.54% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 56.76% ± 3.14% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). Combination treatment of DHA and 5-FU resulted in a significantly larger shift toward the G0/G1 phase and subsequent reduction in S phase (G0/G1 phase: 69.06% ± 2.63% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 19.80% ± 4.30% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). This synergy was also reflected in the significant downregulation of the expression of METCs in AGS cells.

CONCLUSION: Synergistic anticancer properties of DHA and 5-FU may involve interference with energy production of AGS cells via downregulation of METCs and cell cycle arrest.

[Secondary prevention in patients with superficial urothelial carcinoma]

BACKGROUND

Urothelial cancer is the 4th most common cancer in men and the 7th most common malignancy in women in Germany. 95 % of all tumors of the urinary bladder are urothelial carcinomas. At the time of diagnosis approximately 80 % of these carcinomas are not invasive. The affection is often multicentric. Approximately 10-15 % of the tumors develop into muscle-invasive growth. In this prospective study, we analyzed measures patients independently took to reduce their risk of bladder cancer recurrence.

MATERIALS AND METHODS

During the period January 2012 to December 2013, we surveyed a total of 97 patients with superficial transitional cell carcinoma (pTa). The question was how far the diagnosis of urothelial cancer has changed their lives, eating and drinking habits or whether follow-up consultations had been carried out regularly. Furthermore, we recorded whether they accepted psychological care or had autonomously adopted prophylactic measures, as well as changed their smoking habits, if they had smoked.

RESULTS

Of the 97 patients questioned, there were 79 men and 18 women (56 smokers and 41 nonsmokers). The median age was 71 years (range 36-96 years). For 22 patients (22.7 %), the diagnosis resulted in no changes. In 33 patients the changes were small (44 %), moderate in 20 (26.7 %), in 14 (18.6 %) strong and very strong in 8 (10.7 %). A total of 25 patients (25.8 %) changed their eating habits. In all, 49 patients changed their drinking habits; 48 patients claimed to drink more (> 2.0 L/day). One patient reduced his drinking amount. Regarding smoking, 40 patients (71.4 %) had stopped and 7 (12.5 %) reduced consumption, while 6 patients (10.7 %) had not changed their smoking habits. Overall, 44 patients (45.4 %) changed their physical activity: 11 (25 %) exercised more, 8 (18.1 %) less. Only 3 patients (3.1 %) used psycho-oncological care and 39 (40.2 %) patients used supportive/complementary medicine measures of favorablly influence their disease (mistletoe therapy, vitamin supplements). In addition, 22 patients (22.7 %) sought advice from their physician. However, 45.4 % of all patients did not believe in the success of their measures taken.

CONCLUSION

Of all patients diagnosed with urothelial carcinoma, 77.3 % reported a change in their living habits and they were willing to take specific steps, such as giving up smoking, being more physically active, changing drinking and eating habits in order to positively influence their disease. However, almost half of the patients (45.4 %) did not believe in a resounding success of their measures taken.

Omega-3 fatty acids reduce obesity-induced tumor progression independent of GPR120 in a mouse model of postmenopausal breast cancer

Obesity and inflammation are both risk factors for a variety of cancers, including breast cancer in postmenopausal women. Intake of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) decreases the risk of breast cancer, and also reduces obesity-associated inflammation and insulin resistance, but whether the two effects are related is currently unknown. We tested this hypothesis in a postmenopausal breast cancer model using ovariectomized, immune-competent female mice orthotopically injected with Py230 mammary tumor cells. Obesity, whether triggered genetically or by high-fat diet (HFD) feeding, increased inflammation in the mammary fat pad and promoted mammary tumorigenesis. The presence of tumor cells in the mammary fat pad further enhanced the local inflammatory milieu. Tumor necrosis factor-alpha (TNF-α) was the most highly upregulated cytokine in the obese mammary fat pad, and we observed that TNF-α dose-dependently stimulated Py230 cell growth in vitro. An ω-3 PUFA-enriched HFD (referred to as fish oil diet, FOD) reduced inflammation in the obese mammary fat pad in the absence of tumor cells and inhibited Py230 tumor growth in vivo. Although some anti-inflammatory effects of ω-3 PUFAs were previously shown to be mediated by the G-protein-coupled receptor 120 (GPR120), the FOD reduced Py230 tumor burden in GPR120-deficient mice to a similar degree as observed in wild-type mice, indicating that the effect of FOD to reduce tumor growth does not require GPR120 in the host mouse. Instead, in vitro studies demonstrated that ω-3 PUFAs act directly on tumor cells to activate c-Jun N-terminal kinase, inhibit proliferation and induce apoptosis. Our results show that obesity promotes mammary tumor progression in this model of postmenopausal breast cancer and that ω-3 PUFAs, independent of GPR120, inhibit mammary tumor progression in obese mice.

Artesunate induces apoptosis of bladder cancer cells by miR-16 regulation of COX-2 expression

Bladder cancer is the most common malignant tumor of the urinary tract and remains one of the major causes of cancer death worldwide. In this study, we investigated the effect and mechanism of Artesunate (ART), a traditional Chinese medicine, on inducing apoptosis of human bladder cancer cells. In vivo antitumor activity was investigated in bladder cancer in rat by subcutaneous injection of different concentration of ART. The effect of ART on growth inhibition and apoptosis of bladder cancer cells was evaluated using dimethylthiazoly-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Cyclooxygenase-2 (COX-2) and miR-16 expression levels were determined with real-time PCR. The concentrations of prostaglandin E2 (PGE2) in the supernatants of bladder cancer cells were measured with an ELISA kit. The miR-16 inhibitor or mimic were transfected into cells to up- or down-regulate miR-16 expression. ART efficiently inhibited orthotopic tumor growth in the bladder cancer rat, which is accompanied with an increase of miR-16 expression and a decrease of COX-2 expression. In vitro, ART could induce cytotoxicity and apoptosis in bladder cancer cells, but presented a much lighter toxicity effect against normal human urothelial cells. ART significantly increased miR-16 expression and decreased the expression of COX-2 and the production of PGE2. More importantly, down-regulation of miR-16 expression could reverse the effect of ART on apoptosis and COX-2 expression in bladder cells. Moreover, exogenous PGE2 could inhibit apoptosis of bladder cancer cells treated with ART. In conclusion, ART can elicit an anti-tumor effect against bladder cancer by up-regulation of miR-16 expression, which resulted in the decrease of COX-2 expression and PGE2 production. Hence, ART might be an effective drug for the treatment of bladder cancer.

Synergistic anti-tumor effects of combined gemcitabine and cisplatin nanoparticles in a stroma-rich bladder carcinoma model

Tumors grown in a stroma-rich mouse model resembling clinically advanced bladder carcinoma with UMUC3 and NIH 3T3 cells have high levels of fibroblasts and an accelerated tumor growth rate. We used this model to investigate the synergistic effect of combined gemcitabine monophosphate (GMP) nanoparticles and Cisplatin nanoparticles (Combo NP) on tumor-associated fibroblasts (TAFs). A single injection of Combo NP had synergistic anti-tumor effects while the same molar ratio of combined GMP and Cisplatin delivered as free drug (Combo Free) fell outside of the synergistic range. Combo NP nearly halted tumor growth with little evidence of general toxicity while Combo Free had only a modest inhibitory effect at 16mg/kg GMP and 1.6mg/kg Cisplatin. Combo NP increased levels of apoptosis within the tumor by approximately 1.3 folds (TUNEL analysis) and decreased α-SMA-positive fibroblast recruitment by more than 87% (immunofluorescence) after multiple injections compared with Combo Free, GMP NP or Cisplatin NP alone. The TAF-targeting capability of Combo NP was evaluated by double staining for TUNEL and α-SMA at various time points after a single injection. On day one after injection, 57% of the TUNEL-positive cells were identified as α-SMA-positive fibroblasts. By day four, tumor stroma was 85% depleted and 87% of the remaining TAFs were TUNEL-positive. Combo NP-treated tumors became 2.75 folds more permeable than those treated with Combo Free as measured by Evans Blue. We conclude that the antineoplastic effect of Combo NP works by first targeting TAFs and is more effective as an anti-tumor therapy than Combo Free, GMP NP or Cisplatin NP alone.