Abstract 4521: A novel targeted triggered release nanoparticle against cancer cells of diverse histological origin

The paradigm of cancer treatment has changed substantially over the last decade. The discovery of new therapeutic targets within the tumor cell and the recognition of the interdependence with the tumor microenvironment have been the basis of such changes. However, no common ground was yet found for the treatment of cancer within its diverse histological origin. Conventional therapy against human canc¬er, relying on the use of drugs that do not differentiate between cancer and normal cells, is progressively giving room to novel therapeutic strategies. Specificity became mandatory for treatment effectiveness and target selection one of the main priorities. In this scenario, delivery systems rise as promising approaches, for the reason they can improve pharmacokinetic features of anticancer drugs and efficiently address a particular payload to a selected target, namely through exploitation of high specificity and affinity between cell-surface receptors and targeting ligands coupled at their surface.

We evidence the overexpression of a target cell surface receptor (nucleolin) in several cancer cell lines of diverse histological origins: breast (hormone-dependent and triple negative subtypes), colon, prostate and small cell and non-small cell lung cancer. We demonstrate the ability of the nucleolin receptor to specifically internalize a F3-targeted sterically stabilized lipid-based formulation. Moreover, we show that the unique combination of targeting specificity and intracellular triggered release of a therapeutic agent, doxorubicin, results in enhanced cytotoxic activity in those specific cell lines, when compared to the non-targeted counterpart.

Active accumulation of the targeted nanoparticle into human orthotopic tumors, implanted in the mammary fat pad of nude mice, was registered for a time-point as short as 4 h, reaching 48% of the injected dose/g of tissue. Twenty-four hours post-injection accumulation in the tumor tissue was 33-fold higher than the non-targeted counterpart. In mice treated with the targeted nanoparticle containing doxorubicin, significant decrease of the tumor viable rim area and microvascular density, as well as limited invasion to surrounding healthy tissues were observed (as opposed to other tested controls). Moreover, the clinical potential of such strategy was demonstrated by the successful specific cellular association by breast cancer cells harvested from tumors of patients submitted to mastectomy.

Overall, we provide evidence of a nanoparticle with specificity to cancer cells of diverse histological origins and proven therapeutic efficacy in an animal model of breast cancer, which may be a breakthrough in the development of anticancer therapies, especially when considering cancer cell heterogeneity.

Citation Format: Vera Moura, Manuela Lacerda, Paulo Figueiredo, Maria L. Corvo, Maria M E Cruz, Raquel Soares, Sérgio Simões, João Moreira. A novel targeted triggered release nanoparticle against cancer cells of diverse histological origin. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4521. doi:10.1158/1538-7445.AM2013-4521

Osteoblast, fibroblast and in vivo biological response to poly(vinylidene fluoride) based composite materials

Electroactive materials can be taken to advantage for the development of sensors and actuators as well as for novel tissue engineering strategies. Composites based on poly(vinylidene fluoride), PVDF, have been evaluated with respect to their biological response. Cell viability and proliferation were performed in vitro both with Mesenchymal Stem Cells differentiated to osteoblasts and Human Fibroblast Foreskin 1. In vivo tests were also performed using 6-week-old C57Bl/6 mice. It was concluded that zeolite and clay composites are biocompatible materials promoting cell response and not showing in vivo pro-inflammatory effects which renders both of them attractive for biological applications and tissue engineering, opening interesting perspectives to development of scaffolds from these composites. Ferrite and silver nanoparticle composites decrease osteoblast cell viability and carbon nanotubes decrease fibroblast viability. Further, carbon nanotube composites result in a significant increase in local vascularization accompanied an increase of inflammatory markers after implantation.

Substance P antagonist improves both obesity and asthma in a mouse model

BACKGROUND

Evidence suggests a causal relationship between obesity and asthma; however, the underlying mechanisms remain unknown. Substance P (SP), involved in neurogenic inflammation by acting through its receptor NK1-R, seems to participate in obese-asthma phenotype in mice.

OBJECTIVES

To evaluate the effect of a selective substance P receptor antagonist on a mouse model of diet-induced obesity and asthma.

METHODS

Diet-induced obese Balb/c mice were sensitized and challenged with ovalbumin (OVA) and treated with a selective NK1-R antagonist or placebo. Serum glucose, insulin, IL-6, resistin, and OVA-specific IgE levels were quantified. A score for peribronchial inflammation in lung histology was used. Cells were counted in bronchoalveolar lavage fluid. Adipocyte sizes were measured.

RESULTS

Ovalbumin-obese mice treated with NK1-R antagonist had lower weight (P = 0.0002), reduced daily food intake (P = 0.0021), reduced daily energy intake (P = 0.0021), reduced surface adipocyte areas (P < 0.0001), lower serum glucose (P = 0.04), lower serum insulin (P = 0.03), lower serum IL-(P = 0.0022), lower serum resistin (P = 0.0043), lower serum OVA-specific IgE (P = 0.035), and lower peribronchial inflammation score (P < 0.0001) than nontreated OVA-obese mice. We observed an interaction between obesity, allergen sensitization, and treatment with NK1-R antagonist for metabolic and systemic biomarkers, and for allergen sensitization and bronchial inflammation, showing a synergy between these variables.

CONCLUSION & CLINICAL RELEVANCE

In an experimental model of obesity and asthma in mice, NK1-R blockade improved metabolic and systemic biomarkers, as well as allergen sensitization and bronchial inflammation. These positive effects support a common pathway in the obese-asthma phenotype and highlight SP as a target with potential clinical interest in the obese-asthma epidemics.

Neurogenic inflammation in allergen-challenged obese mice: A missing link in the obesity-asthma association?

AIM

A number of studies have shown an association between obesity and asthma. Controversy remains on the mechanisms supporting this association. In this study we aimed to assess neurogenic inflammation in a model of diet-induced obesity and allergen-challenged mice.

METHODS

High fat diet-induced (HFD) obese Balb/c mice were sensitized and challenged with ovalbumin (OVA). Glucose, insulin, OVA-specific IgE and substance P (SP), and the main tachykinin involved in neurogenic inflammation, were quantified in sera. Cell counts were performed in bronchoalveolar lavage fluid (BALF). The extent of peribronchial infiltrates was estimated on lung tissue sections and inflammation was score based on inflammatory cell counts surrounding the bronchi.

RESULTS

Obesity per se and allergen-sensitization per se increased serum SP (P = .027, P = .004, respectively). Further increased was observed in obese-sensitized mice (P = .007). Obese-sensitized mice also showed higher insulin (P = .0016), OVA-specific IgE (P = .016), peribronchial inflammatory score (P = .045), and tendency for higher glycemia. The interaction of obesity and asthma on SP levels was confirmed (P = .005, R(2) = 0.710). SP was positively correlated with metabolic (glycemia, r = 0.539, P = .007) and allergic inflammation parameters (BALF eosinophils, r = 0.445, P = 0.033; BALF mast cells, r = 0.574, P = .004; peribronchial inflammation score, r = 0.661, P < .001; and OVA-specific IgE, r = 0.714, P < .001).

CONCLUSIONS

Our findings provide support to the neurogenic inflammation link between obesity and asthma in mice. These two conditions independently increased SP and the presence of both pathologies further increased this level. Neurogenic inflammation may be a previously unrecognized mechanism beyond the obese-asthma phenotype. Further studies are need to confirm this role of SP in human obesity-asthma association.

Xanthohumol-supplemented beer modulates angiogenesis and inflammation in a skin wound healing model. Involvement of local adipocytes

Angiogenesis and inflammation are two intermingled processes that play a role in wound healing. Nevertheless, whenever exacerbated, these processes result in nonhealing wounds. Xanthohumol (XN), a beer-derived polyphenol, inhibits these processes in many physiopathological situations. This study aimed at examining whether XN ingestion affects wound healing. Wistar rats drinking water, 5% ethanol, stout beer (SB) or stout beer supplemented with 10 mg/L XN (Suppl SB) for 4 weeks, were subjected to a 1.5 cm full skin-thickness longitudinal incision, and further maintained under the same beverage conditions for another week. No differences in beverage consumption or body weight were found throughout the study but food intake decreased in every group relative to controls. Consumption of Suppl SB resulted in decreased serum VEGF levels (18.42%), N-acetylglucosaminidase activity (27.77%), IL1β concentration (9.07%), and NO released (77.06%), accompanied by a reduced redox state as observed by increased GSH/GSSG ratio (to 198.80%). Also, the number of blood vessels within the wound granulation tissue seems to reduce in animals drinking Suppl SB (23.08%). Interestingly, SB and primarily Suppl SB showed a tendency to increase adipocyte number (to 194.26% and 156.68%, respectively) and reduce adipocyte size (4.60% and 24.64%, respectively) within the granuloma. Liver function and metabolism did not change among the animal groups as analyzed by plasma biochemical parameters, indicating no beverage toxicity. This study shows that XN intake in its natural beer context reduced inflammation, oxidative stress, and angiogenesis, ameliorating the wound healing process, suggesting that this polyphenol may exert beneficial effect as a nutritional supplement.

Targeted and intracellular triggered delivery of therapeutics to cancer cells and the tumor microenvironment: impact on the treatment of breast cancer

Limiting tumor invasion to the surrounding healthy tissues has proven to be clinically relevant for anticancer treatment options. We have demonstrated that, within a solid tumor, it is possible to achieve such a goal with the same nanoparticle by intracellular and triggered targeted drug delivery to more than one cell population. We have identified the nucleolin receptor in endothelial and cancer cells in tissue samples from breast cancer patients, which enabled the design of a F3-peptide-targeted sterically stabilized pH-sensitive liposome. The clinical potential of such strategy was demonstrated by the successful specific cellular association by breast cancer cells harvested from tumors of patients submitted to mastectomy. In vitro, the nanoparticle targeted the nucleolin receptor on a cell and ligand-specific manner and improved cytotoxicity of doxorubicin (used as a model drug) towards breast cancer and endothelial cells by 177- and 162-fold, respectively, relative to the commercially available non-targeted non-pH-sensitive liposomes. Moreover, active accumulation of F3-targeted pH-sensitive liposomes into human orthotopic tumors, implanted in the mammary fat pad of nude mice, was registered for a time point as short as 4 h, reaching 48% of the injected dose/g of tissue. Twenty-four hours post-injection the accumulation of the dual-targeted pH-sensitive nanoparticle in the tumor tissue was 33-fold higher than the non-targeted non-pH-sensitive counterpart. In mice treated with the developed targeted nanoparticle significant decrease of the tumor viable rim area and microvascular density, as well as limited invasion to surrounding healthy tissues were observed (as opposed to other tested controls), which may increase the probability of tumors falling in the category of "negative margins" with reduced risk of relapse.

Differentially expressed angiogenic genes in diabetic erectile tissue - results from a microarray screening

Diabetes-induced metabolic derangements promote endothelial malfunction, contributing to erectile dysfunction (ED). However, it remains unclear which angiogenic molecular mechanisms are deregulated in diabetic corpus cavernosum (CC). We investigated early and late alterations in cavernosal angiogenic gene expression associated to diabetes. Angiogenic changes were assessed in penile tissue of streptozotocin-induced Wistar rats, in an early (2-week) and established stage (8-week) of diabetes. Differentially expressed genes were identified by microarrays and expression data validated by quantitative real-time PCR (qrt-PCR). At protein level, quantitative immunohistochemistry confirmed the arrays data and dual immunofluorescence for selected alterations and α-smooth muscle actin (α-SMA) identified the cellular location of target proteins. The selected differentially expressed genes were also evaluated in human non-diabetic and diabetic CC by quantitative immunolabeling. At 2-week diabetes there was no differential gene expression between non-diabetic and diabetic CC. At 8-week, 10 genes were found down-regulated in diabetics. The results were validated by qrt-PCR for the insulin-like growth factor-1 (Igf1) and the natriuretic peptide receptor-1 (Npr1) genes. Dual immunofluorescence for IGF-1/ α-SMA showed predominant localization of IGF-1 in SM. NPR-1 expression was diffuse and mostly present in trabecular fibroblasts and SM. Quantitative immunostaining confirmed the decreased expression of both proteins in diabetic tissues. Concordantly, we detected a significant reduction in IGF-1 and NPR-1 protein expressions in human diabetic samples. Microarray analysis identified 10 angiogenic-related molecules deregulated in CC of established diabetes. Among them, IGF-1 and NPR-1 were significantly down-regulated and might result in preventive/therapeutic targets for ED management.

Vascular endothelial growth factor plasma levels before and after treatment of neovascular age-related macular degeneration with bevacizumab or ranibizumab

PURPOSE

To evaluate the changes of vascular endothelial growth factor (VEGF) plasma levels after intravitreal injections of ranibizumab or bevacizumab in patients with exudative age-related macular degeneration (AMD).

METHODS

Forty-three patients with exudative AMD and 19 age- and sex-matched control patients without chorioretinal diseases were studied. Nineteen patients were treated with intravitreal ranibizumab 0.5 mg, 24 with intravitreal bevacizumab 1.25 mg. Blood samples were collected just before the first injection, and 28 days after three initial consecutive injections performed in 4-weekly intervals (loading dose). Concentration of VEGF in the plasma was measured by ELISA.

RESULTS

At baseline, the median VEGF concentrations in controls were 180.97 pg/ml, in the bevacizumab group 189.72 pg/ml and in the ranibizumab group 191.36 pg/ml. VEGF plasma concentrations in patients with wet AMD were comparable to controls (p = 0.225). Twenty-eight days after the third injection, a significant reduction of 42% in the median VEGF plasma levels was found in bevacizumab-treated patients (109.97 pg/ml; p = 0.0002) but not in ranibizumab-treated patients (189.97 pg/ml; p = 0.198) where a reduction of 0.7% in the median value was found.

CONCLUSIONS

Intravitreal bevacizumab significantly reduced VEGF plasma levels until 28 days after intravitreal injection in patients with exudative AMD. Ranibizumab did not achieve a significant plasma VEGF reduction at the same time-point. These findings alert to the potential systemic safety differences between the two drugs after intravitreal administration.

Tachykinin receptors antagonism for asthma: a systematic review

Background

Tachykinins substance P, neurokinin A and neurokinin B seem to account for asthma pathophysiology by mediating neurogenic inflammation and several aspects of lung mechanics. These neuropeptides act mainly by their receptors NK1, NK2 and NK3, respectively which may be targets for new asthma therapy.

Methods

This review systematically examines randomized controlled trials evaluating the effect of tachykinins receptors antagonism on asthma. Symptoms, airway inflammation, lung function and airway inflammation were considered as outcomes. We searched the Cochrane Airways Group Specialized Register of Asthma Trials, Cochrane Database of Systematic Reviews, MEDLINE/PubMed and EMBASE. The search is as current as June 2010. Quality rating of included studies followed the Cochrane Collaboration and GRADE Profiler approaches. However, data were not pooled together due to different measures among the studies.

Results

Our systematic review showed the potential of NK receptor antagonist to decrease airway responsiveness and to improve lung function. However, effects on airway inflammation and asthma symptoms were poorly or not described.

Conclusion

The limited available evidence suggests that tachykinin receptors antagonists may decrease airway responsiveness and improve lung function in patients with asthma. Further large randomized trials are still required.

Wound healing activity of the human antimicrobial peptide LL37

Antimicrobial peptides (AMPs) are part of the innate immune system and are generally defined as cationic, amphipathic peptides, with less than 50 amino acids, including multiple arginine and lysine residues. The human cathelicidin antimicrobial peptide LL37 can be found at different concentrations in many different cells, tissues and body fluids and has a broad spectrum of antimicrobial and immunomodulatory activities. The healing of wound is a complex process that involves different steps: hemostasis, inflammation, remodeling/granulation tissue formation and re-epithelialization. Inflammation and angiogenesis are two fundamental physiological conditions implicated in this process. We have recently developed a new method for the expression and purification of recombinant LL37. In this work, we show that the recombinant peptide P-LL37 with a N-terminus proline preserves its immunophysiological properties in vitro and in vivo. P-LL37 neutralized the activation of macrophages by lipopolysaccharide (LPS). Besides, the peptide induced proliferation, migration and tubule-like structures formation by endothelial cells. Wound healing experiments were performed in dexamethasone-treated mice to study the effect of LL37 on angiogenesis and wound regeneration. The topical application of synthetic and recombinant LL37 increased vascularization and re-epithelialization. Taken together, these results clearly demonstrate that LL37 may have a key role in wound regeneration through vascularization.

Erectile tissue molecular alterations with aging: differential activation of the p42/44 MAP Kinase pathway

Erectile dysfunction (ED) is a common problem in aged men; however, the molecular events involved in aging ED remain unclear. To better characterize the effects of aging in the penis, we evaluated cavernosal tissue remodeling capability and the downstream activation of the intracellular signaling mediator mitogen-activated protein p42/44 kinase (p42/44 MAPK). We used male Wistar rats, which were divided in groups of 2, 6, 12, 18, and 24 months old. Penile tissues were harvested and processed for protein isolation and immunohistochemical analysis. Cavernosal viability was assessed by TUNEL assay, and proliferation was analyzed by immunohistochemical detection of proliferating cell nuclear antigen (PCNA). Immunolocalization of the activated form of p42/44 MAPK was evaluated by immunofluorescence, and changes in its phosphorylation status were quantified by western blotting. p42/44 phosphorylation profile was also assessed in situ in human young and elderly cavernosal samples. With the advancement of age, experimental cavernosal tissue remodeling was affected by an age-dependent unbalance between the rate of apoptosis and proliferation, in all erectile components. Moreover, this turnover alteration was accompanied by significant modifications in the activation profile of the downstream effector p42/44 MAPK. In the youngest corporeal samples, p42/44 was mostly activated at perivascular sites, potentially mediating cell survival/proliferation. However, in elderly experimental erectile tissue, p42/44 phosphorylation shifted to trabecular fibroblasts, indicating a potential role in extracellular matrix (ECM) production. More importantly, the same differential pattern of p42/44 activation was observed in human young and aged cavernosal fragments, suggesting a distinct function of this protein with aging. We provided evidence for the first time that with the advancement of age, there is a differential activation of p42/44 MAPK in cavernosal tissue, which may promote ECM expansion and fibrosis, therefore compromising erectile function in the elderly.

Angiogenesis and inflammation signaling are targets of beer polyphenols on vascular cells

Emerging evidence indicates that chronic inflammation and oxidative stress cluster together with angiogenic imbalance in a wide range of pathologies. In general, natural polyphenols present health-protective properties, which are likely attributed to their effect on oxidative stress and inflammation. Hops used in beer production are a source of polyphenols such as xanthohumol (XN), and its metabolites isoxanthohumol (IXN) and phytoestrogen 8-prenylnaringenin (8PN). Our study aimed to evaluate XN, IXN, and 8PN effects on angiogenesis and inflammation processes. Opposite in vitro effects were observed between 8PN, stimulating endothelial and smooth muscle cell (SMC) growth, motility, invasion and capillary-like structures formation, and XN and IXN, which inhibited them. Mouse matrigel plug and rat skin wound-healing assays confirmed that XN and IXN treatments reduced vessel number as well as serum macrophage enzymatic activity, whereas 8PN increased blood vessels formation in both assays and enzyme activity in the wound-healing assay. A similar profile was found for serum inflammatory interleukin-1β quantification, in the wound-healing assay. Our data indicate that whereas 8PN stimulates angiogenesis, XN and IXN manifested anti-angiogenic and anti-inflammatory effects in identical conditions. These findings suggest that the effects observed for individual compounds on vascular wall cells must be carefully taken into account, as these polyphenols are metabolized after in vivo administration. The modulation of SMC proliferation and migration is also of special relevance, given the role of these cells in many pathological conditions. Furthermore, these results may provide clues for developing useful therapeutic agents against inflammation- and angiogenesis-associated pathologies.