Inhibition of angiotensin pathway via valsartan reduces tumor growth in models of colorectal cancer.

BACKGROUND: Overexpression of the angiotensin-II receptor and renin-angiotensin system (RAS) has been reported in several malignancies, including colorectal-cancer (CRC), indicating its potential value as a therapeutic target. Here we explored the impact of targeting the RAS using an angiotensin II receptor blocker, valsartan, alone and its combination with Fluorouracil (5-FU) in in vitro and in vivo models of CRC. METHODS: Anti-proliferative activity of valsartan was evaluated in 2-/3-dimensional in vitro and in vivo CRC mouse models. The anti-migratory effects of this agent was assessed by wound-healing assay, while apoptosis was studied using 4',6-diamidino-2-phenylindole or DAPI staining, and staining with Annexin-V-fluorescein isothiocyanate with analysis using FACS. Gene-expression was determined at mRNA and protein levels. We further evaluated the anti-inflammatory properties of valsartan by histological analysis and the measurement of oxidative/antioxidant markers. Gelatin zymography was used to measure matrix metalloproteinase-2 and -9 activity (MMP-2 and 9). RESULTS: Valsartan suppressed CRC cell-growth and synergistically enhanced the anti-tumor-activities of 5-FU by induction of apoptosis, BAX, BCL2, P53 and modulation of the cell cycle. Valsartan inhibited the cell migration by perturbation of MMP2/9. Furthermore, valsartan inhibited tumor-growth, and this was more pronounced when using the valsartan/5-FU combination. The plausible mechanism for this is via the induction of ROS and down-regulation of SOD, thiol/catalase as well as VEGF. Valsartan may protect cells against intestinal fibrosis by modulation of pro-fibrotic and pro-inflammatory factors including interleukins and Col1A1 expression. CONCLUSIONS: Our findings demonstrated that targeting RAS pathway using Valsartan interferes with cell-proliferation, induces apoptosis, reduces migration and synergistically interacts with 5-FU, supporting further studies on this new therapeutic approach for colorectal cancer.

The therapeutic potential of γ-Al2O3 nanoparticle containing 5-fluorouracil in the treatment of colorectal cancer.

5-Fluorouracil (5-FU) is being used in the treatment of several malignancies, but side effects are often reported and include: diarrhea, vomiting, nausea, poor appetite, watery eyes, and photophobia. We have developed and tested the cytotoxic activity of nanocrystalline powder of γ-alumina (γ-Al2O3) containing 5-FU in two-dimensional and three-dimensional (3D) CRC cell culture. γ-Al2O3 was prepared using a facile sol-gel method. The physicochemical properties of nanoparticles were investigated by Fourier Transform Infrared (FTIR) analysis, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Analysis (EDXA). Moreover, the particle size was monitored by Transmission Electron Microscopy (TEM). We used MTT and a scratch assay to assess the antiproliferative and anti-migratory of this agent. The effect of γ-Al2O3-5-FU on SOD, MDA, and total-thiols levels were evaluated. We assessed the expression of apoptotic markers in mRNA or proteins by RT-PCR and ELISA respectively. γ-Al2O3-5-FU inhibited cell growth in two-dimensional (2D) and three-dimensional (3D) cell culture and increased apoptosis as detected by DAPI stainning via modulation of caspases, BAx, BCl2 and cyclinD1. γ-Al2O3-5-FU also reduced the migratory activity of CRC cells relative to untreated controls. γ-Al2O3-5-FU increased the level of MDA, while reducing the level of SOD and total-thiols as well as inflamatory markers (e.g., TNF-s and IL-6). Our study demonstrated that γ-Al2O3-5-FU inhibited cell growth and migration, indicating its potential value in the treatment of colorectal cancer.

Inhibition of the Wnt/b-catenin pathway using PNU-74654 reduces tumor growth in in vitro and in vivo models of colorectal cancer.

BACKGROUND: Colorectal-cancer (CRC) is amongst the most lethal-cancers, mainly due to its metastatic spread and drug chemoresistance. Hence there is a need for new approaches to either increase the efficacy of current therapy or introduce new therapies that have greater efficacy. There is increasing evidence that dysregulation of WNT-signaling-pathway plays an essential role in the development and prognosis of CRC. Here we have investigated the therapeutic potential of targeting the WNT/b-catenin pathway using a novel Wnt/b-catenin inhibitor, PNU-74654, in combination with 5-FU in CRC. METHODS: The anti-proliferative-effect of PNU-74654 was evaluated in two-/three-dimensional cell models. The activity of agents on cell growth, migration, invasion, cell cycle and apoptosis was evaluated by MTT, wound healing assay, invasion, FACS, and annexin V staining, respectively. The oxidant/antioxidant levels were also assessed by determining the level of MDA, SOD, as well as using the DCFH-DA assay. We used a xenograft model of CRC to investigate PNU-74654 activity alone and in combination with 5-FU follow by histological staining and biochemical and gene expression analyses by RT-PCR and western blot. RESULTS: PNU-74654 inhibited cell-growth and synergistically affected the anti-tumor properties of 5-FU via modulation of Cyclin D1 and survivin. This agent inhibited the migration/invasion of colorectal cancer cells via perturbation of E-cadherin. Furthermore, PNU-74654 inhibited the tumor growth, which was more pronounced using the PNU-74654 plus 5-FU combination via induction of reactive oxygen species, down-regulation of SOD and modulation of MCP-1, P53, TNF-α. CONCLUSIONS: Our finding demonstrated that PNU-74654 can target Wnt-pathway, interfere with cell-proliferation, induced-cell death, reduced-migration and interact with 5-FU, supporting further investigations on this therapeutic-approach for colorectal cancer.

Pathogenic role of the SP/ NK1R system in GBM cells through inhibiting the thioredoxin system.

OBJECTIVES: Glioblastoma multiforme (GBM), a highly aggressive Grade IV brain tumor, is a significant public health issue due to its poor prognosis and incurability. Neuropeptide substance P (SP) plays a critical role in GBM tumor growth and development via activation of neurokinin-1receptor (NK1R). Moreover, SP is a pro-oxidant factor contributing to oxidative stress in various cell types. However, the link between SP and oxidative stress in cancer cells is not fully investigated. Here, we aimed to identify the effects of SP and NK1R antagonist, aprepitant, on the redox status of GBM cells. MATERIALS AND METHODS: Resazurin assay was employed to determine the effect of aprepitant on viability of U87 glioblastoma cells. 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) assay was employed to measure the levels of intracellular reactive oxygen species (ROS). A quantitative real-time polymerase chain reaction was applied to measure the expression of proteins of the thioredoxin system. Commercial kits (ZellBio GmbH) were also used to measure the enzymatic activity of these proteins. RESULTS: We found that SP increased ROS level in U87 GBM cells, and aprepitant significantly reduced this effect. Furthermore, we found that SP could also affect the thioredoxin system, a central antioxidant enzyme defense system. SP reduced both expression and enzymatic activity of the thioredoxin system's proteins, Trx and thioredoxin reductase (TrxR) and these effects were significantly reduced by aprepitant. CONCLUSION: Our results indicated that SP activation of NK1R represented a link between oxidative stress and GBM and highlighted the need for further validations in future studies.

Evaluation of the serum prooxidant-antioxidant balance before and after vitamin D supplementation in adolescent Iranian girls.

PURPOSE: Oxidative stress is caused by an imbalance between the antioxidant defenses and pro-oxidant production in favor of pro-oxidant production. Vitamin D has the potential for both pro- and anti-oxidative effects. The aim of this study was to assess the effect of high dose vitamin D supplementation on the prooxidant-antioxidant balance (PAB) in Iranian girls attending High School. MATERIALS AND METHODS: A total of 464 girls aged 12-18 years were asked to take vitamin D capsules containing 50000IU vitamin D3 once a week for a period of 9 weeks. All variables were determined at baseline and after 9 weeks of intervention. Fasting blood samples were taken from all subjects. The serum levels of 25OHD were measured using an electrochemiluminescence method. Serum PAB levels were determined using an ELISA reader at a wavelength of 450 nm. RESULTS: Vitamin D supplementation was associated with an increase in serum PAB (P < 0.001) and a reduction in serum LDL-C (P < 0.001), total cholesterol (P < 0.001) and HDL-C (P < 0.01) serum levels in Iranian adolescent girls. The results obtained from the current study show that there were significant improvements in weight (P < 0.001), BMI (P < 0.001) and FBG (P = 0.02) in adolescent girls who had 50-74.9 nmol/L serum 25OHD levels compared to <50 nmol/L ones after the vitamin D supplementation. There was no significant association between the serum PAB and all biochemical factors (P > 0.05 for all variables). CONCLUSIONS: The results showed that vitamin D supplementation has increased the PAB levels in teenage girls.