Combined Supplementation with Vitamin B-6 and Curcumin is Superior to Either Agent Alone in Suppressing Obesity-Promoted Colorectal Tumorigenesis in Mice

ABSTRACT Background Obesity increases the colorectal cancer risk, in part by elevating colonic proinflammatory cytokines. Curcumin (CUR) and supplemental vitamin B-6 each suppress colonic inflammation. Objectives We examined whether the combination of CUR and vitamin B-6 amplifies each supplement's effects and thereby suppress obesity-promoted tumorigenesis. Methods Male Friend Virus B (FVB) mice (4-week-old; n = 110) received 6 weekly injections of azoxymethane beginning 1 week after arrival. Thereafter, they were randomized to receive a low-fat diet (10% energy from fat), a high-fat diet (HFD; 60% energy from fat), a HFD containing 0.2% CUR, a HFD containing supplemental vitamin B-6 (24 mg pyridoxine HCl/kg), or a HFD containing both CUR and supplemental vitamin B-6 (C + B) for 15 weeks. Colonic inflammation, assessed by fecal calprotectin, and tumor metrics were the primary endpoints. The anti-inflammatory efficacy of the combination was also determined in human colonic organoids. Results HFD-induced obesity produced a 2.6-fold increase in plasma IL-6 (P < 0.02), a 1.9-fold increase in fecal calprotectin (P < 0.05), and a 2.2-fold increase in tumor multiplicity (P < 0.05). Compared to the HFD group, the C + B combination, but not the individual agents, decreased fecal calprotectin (66%; P < 0.01) and reduced tumor multiplicity and the total tumor burden by 60%–80% (P < 0.03) in an additive fashion. The combination of C + B also significantly downregulated colonic phosphatidylinositol-4,5-bisphosphate 3-kinase, Wnt, and NF-κB signaling by 31%–47% (P < 0.05), effects largely absent with the single agents. Observations that may explain how the 2 agents work additively include a 2.8-fold increased colonic concentration of 3-hydroxyanthranillic acid (P < 0.05) and a 1.3-fold higher colonic concentration of the active coenzymatic form of vitamin B-6 (P < 0.05). In human colonic organoids, micromolar concentrations of CUR, vitamin B-6, and their combination suppressed secreted proinflammatory cytokines by 41%–93% (P < 0.03), demonstrating relevance to humans. Conclusions In this mouse model, C + B is superior to either agent alone in preventing obesity-promoted colorectal carcinogenesis. Augmented suppression of procancerous signaling pathways may be the means by which this augmentation occurs.

Knockout of Putative Tumor Suppressor Aldh1l1 in Mice Reprograms Metabolism to Accelerate Growth of Tumors in a Diethylnitrosamine (DEN) Model of Liver Carcinogenesis

Cytosolic 10-formyltetrahydrofolate dehydrogenase (ALDH1L1) is commonly downregulated in human cancers through promoter methylation. We proposed that ALDH1L1 loss promotes malignant tumor growth. Here, we investigated the effect of the Aldh1l1 mouse knockout (Aldh1l1−/−) on hepatocellular carcinoma using a chemical carcinogenesis model. Fifteen-day-old male Aldh1l1 knockout mice and their wild-type littermate controls (Aldh1l1+/+) were injected intraperitoneally with 20 μg/g body weight of DEN (diethylnitrosamine). Mice were sacrificed 10, 20, 28, and 36 weeks post-DEN injection, and livers were examined for tumor multiplicity and size. We observed that while tumor multiplicity did not differ between Aldh1l1−/− and Aldh1l1+/+ animals, larger tumors grew in Aldh1l1−/− compared to Aldh1l1+/+ mice at 28 and 36 weeks. Profound differences between Aldh1l1−/− and Aldh1l1+/+ mice in the expression of inflammation-related genes were seen at 10 and 20 weeks. Of note, large tumors from wild-type mice showed a strong decrease of ALDH1L1 protein at 36 weeks. Metabolomic analysis of liver tissues at 20 weeks showed stronger differences in Aldh1l1+/+ versus Aldh1l1−/− metabotypes than at 10 weeks, which underscores metabolic pathways that respond to DEN in an ALDH1L1-dependent manner. Our study indicates that Aldh1l1 knockout promoted liver tumor growth without affecting tumor initiation or multiplicity.

Efficacy of fluvastatin and aspirin for prevention of hormonally insensitive breast cancer

Purpose Primary prevention of hormonally insensitive breast cancers remains an important clinical need and repurposing existing low-toxicity drugs represents a low-cost, efficient strategy for meeting this goal. This study targeted the cholesterol pathway using fluvastatin, a cholesterol-lowering drug, and aspirin, an AMPK activator that acts as a brake in the cholesterol pathway, in a transgenic mouse model of triple-negative breast cancer (TNBC). Methods Using SV40C3 TAg mice, the efficacy and mechanism of fluvastatin, aspirin, or both in combination were compared with vehicle alone. Results Sixteen-weeks of fluvastatin treatment resulted in significant delay in onset of tumors (20 weeks vs. 16.8 weeks in vehicle treatment, p = 0.01) and inhibited tumor incidence and tumor multiplicity by 50% relative to the vehicle control. In animals that developed tumors, fluvastatin treatment inhibited tumor weight by 75% relative to vehicle control. Aspirin alone did not significantly affect tumor latency, tumor incidence or tumor burden compared to vehicle control. Fluvastatin and aspirin in combination delayed the onset of tumors but failed to inhibit tumor incidence and tumor multiplicity. The growth-inhibitory effects of fluvastatin were mediated through increased FAS/FASL mediated apoptotic cell death that was characterized by increased cleaved PARP and driven in part by depletion of an isoprenoid, geranyl geranyl pyrophosphate (GGPP). Conclusions In line with NCI’s emphasis to repurpose low-toxicity drugs for prevention of cancer, fluvastatin was effective for prevention of TNBC and warrants further clinical testing. Aspirin did not provide chemopreventive benefit.

Helicobacter pylori infection reduces TAMs infiltration in a mouse model of AOM/DSS induced colitis-associated cancer

Inflammatory bowel disease (IBD) increases the risk of colitis-associated cancer (CAC). Evidences suggest that Helicobacter pylori (H. pylori) infection is associated with a low risk of IBD and protects against experimental colitis in mouse models. However, the effect of H. pylori infection in CAC remains unclear. We previously reported that H. pylori infection increased M2 macrophages in dextran sodium sulfate (DSS)-induced chronic colitis. Tumor-associated macrophages (TAMs) play a pivotal role in colon cancer. Therefore, we established a H. pylori-infected CAC mouse model induced by azoxymethane and DSS to explore the effect of H. pylori infection on TAMs in CAC. Here, we demonstrated that H. pylori infection attenuated the development of CAC by decreasing tumor multiplicity, tumor size, tumor grade and colitis scores. Moreover, H. pylori infection reduced the infiltration of TAMs, particularly M2-like TAMs in CAC tumors, accompanied with the down-regulated pro-inflammatory and pro-tumorigenic factors TNF-α, IL-1β, IL-6 and IL-23 in tumors of CAC mice. Our study suggests that H. pylori infection can reduce TAMs infiltration and regulate cytokines expression in CAC.

Potency of Curcuma aeruginosa as A Chemopreventive Candidate Agent on 7,12-Dimethylbenz[a]anthracene (DMBA)-Induced Rat Spleen

Present investigation shows that the extract of C. aeruginosa attenuates DMBA-induced spleen carcinogenesis in Wistar rats. Three-week female Wistar rats were treated with three different C. aeruginosa extract doses (CA1: 40 mg/200 g body weight, BW; CA2: 80 mg/200 g BW; CA3: 160 mg/200 g BW) and were induced with DMBA after one-week administration of these doses. A commercial immunostimulant, and DMBA only were also given to each group as positive and negative control, respectively. The development of tumors was evaluated by investigating the incidence of tumor and tumor multiplicity during the experiment. Spleen mass index and histological parameters such as white pulp, centrum germinativum, and marginalis zone were also examined. Based on our study, the administration of C. aeruginosa extract during and after carcinogen induction gave several impacts on rat carcinogenesis. At the extract dose of 80 mg/200 g BW, tumor incidence of animals were least (P<0.05). However, all doses did not show any effect to the spleen mass index, though the highest dose (160 mg/200 g BW) was found to cause changes in white pulp and marginalis zone boards. This trend indicates that it takes higher dose to cause an immune response effect reaching the organs.

The gut microbiota modulates differential adenoma suppression by B6/J and B6/N genetic backgrounds in ApcMin mice

Tumor multiplicity in the ApcMin (Min) mouse model of CRC is a classic quantitative trait that is subject to complex genetic and environmental factors, and therefore serves as an ideal platform to study modifiers of disease. While disparate inbred genetic backgrounds have well-characterized modifying effects on tumor multiplicity, it is unclear whether more closely related backgrounds such as C57BL/6J and C57BL6/N differentially modify the phenotype. Furthermore, it is unknown whether the complex gut microbiota (GM) influences the effects of these background strains. We assessed tumor multiplicity in F1 mice generated from the original Min colony from the McArdle Laboratory at the University of Wisconsin (C57BL/6JMlcr-ApcMin) crossed with either C57BL/6J or C57BL/6N wild-type mice. We also used complex microbiota targeted rederivation to rederive B6NB6JMF1-ApcMin embryos using surrogate dams harboring complex GMs from two different sources to determine the effects of complex GM. Both B6/J and B6/N backgrounds significantly repressed tumor multiplicity. However, the B6/N background conferred a stronger dominant suppressive effect than B6/J. Moreover, we observed that complex GM likely modulated B6/N-mediated adenoma repression such that two distinct communities conferred differential tumor multiplicity in isogenic B6NB6JMF1-ApcMin mice. Although we cannot rule out possible maternal effects of embryo transfer, we show that B6/J and B6/N have modifier effects on Min, and these effects are further altered by the complex GM. Foremost, strict attention to genetic background and environmental variables influencing the GM is critical to enhance reproducibility in models of complex disease traits.

Inhibitory Effect of Filipendula ulmaria on Mammary Carcinogenesis Induced by Local Administration of Methylnitrosourea to Target Organ in Rats

Background: The meadowsweet (Filipendula ulmaria (L.) Maxim.) may have a cancer prophylactic activity, since its extracts exhibit antioxidant, anti-inflammatory and other effects. We investigated the ability of a meadowsweet decoction to inhibit mammary carcinogenesis induced by intramammary injections of Methylnitrosourea (MNU) to the target organ in rats. Materials and Methods: The chemical composition of meadowsweet extracts was studied by traditional methods. In animal experiments, adult outbred female rats received single injections of MNU at a dose 1mg directly into the tissue of each mammary gland. After carcinogenic exposure one group (MNU) of rats continued to receive standard feed and tap water throughout life. In another group (MNU+meadowsweet), rats were given daily a decoction of the meadowsweet instead of drinking water and standard feed. Results: Meadowsweet extracts showed a sufficiently high content of flavonoids and tannins and also some individual phenolic compounds. In rats after injections of MNU the overall incidence of tumors was 90% with tumor multiplicity of 3.1. The majority of rats (86%) developed multiple malignant tumors of the mammary gland (most often adenocarcinomas). In rats from the group MNU+meadowsweet, there was a statistically significant decrease of the overall tumor multiplicity-by 1.5 times, and the incidence and multiplicity of breast tumors-by 1.6 and 2.2 times, respectively. Conclusions: Meadowsweet extract can be considered an effective inhibitor of breast carcinogenesis.

Resveratrol chemoprotective effect and COX 2 down regulation in tumor suppression in DMBA induced breast cancer in female Sprague Dawley rats

Background: Aim of the study was to assess the Chemo protective role of Resveratrol in 7,12‑Dimethylbenzanthracene (DMBA) induced breast cancer in Female Sprague Dawley rats and its possible role in down regulation of COX 2, an enzyme known to be expressed in breast cancer tissues.Methods: A total of 40 female Sprague dawley rats (total 4 groups, n = 10 per group) 6 weeks old, group 1 on pulverized rodent diet, group 2 DMBA with diet, group 3 DMBA and diet with Resveratrol 100mcg, group 4 DMBA and diet with Resveratrol 200mcg. After 120 days experiment was terminated and tumors were analyzed for multiplicity, incidence and histology. Cox 2 expression was analyzed by Western blot analysis. Values were statistically tested using one way variance and Tukey’s comparison test.Results: Body weight and tumor volume was similar, there was remarkable high latency period for tumor onset and reduction in tumor multiplicity andincidence in resveratrol treated groups. Tumor incidence was 42.27±10.17 for Group 2, 21.91±5.87 for Group 3, 13.73±3.98 for group 4. Tumor multiplicity was reported as 0.8909±0.30 for group 2, 0.1036±0.04 for group 3, 0.04545±0.02 for group 4. Histopathological analysis revealed ductal carcinoma in group 2, minor tissue necrosis in group 3 and fibroadenoma in group 4.Conclusions: Resveratrol has chemoprevention action against DMBA induced breast cancer and suppresses COX 2 expression in breast carcinoma.