Cell Membrane Fragment-Wrapped Parenteral Nanoemulsions: A New Drug Delivery Tool to Target Gliomas

Poor prognosis in high-grade gliomas is mainly due to fatal relapse after surgical resection in the absence of efficient chemotherapy, which is severely hampered by the blood-brain barrier. However, the leaky blood-brain-tumour barrier forms upon tumour growth and vascularization, allowing targeted nanocarrier-mediated drug delivery. The homotypic targeting ability of cell-membrane fragments obtained from cancer cells means that these fragments can be exploited to this aim. In this experimental work, injectable nanoemulsions, which have a long history of safe clinic usage, have been wrapped in glioma-cell membrane fragments via co-extrusion to give targeted, homogeneously sized, sterile formulations. These systems were then loaded with three different chemotherapeutics, in the form of hydrophobic ion pairs that can be released into the target site thanks to interactions with physiological components. The numerous assays performed in two-dimensional (2D) and three-dimensional (3D) cell models demonstrate that the proposed approach is a versatile drug-delivery platform with chemo-tactic properties towards glioma cells, with adhesive interactions between the target cell and the cell membrane fragments most likely being responsible for the effect. This approach's promising translational perspectives towards personalized nanomedicine mean that further in vivo studies are foreseen for the future.

Discovery of a septin-4 covalent binder with antimetastatic activity in a mouse model of melanoma

Cancer spreading through metastatic processes is one of the major causes of tumour-related mortality. Metastasis is a complex phenomenon which involves multiple pathways ranging from cell metabolic alterations to changes in the biophysical phenotype of cells and tissues. In the search for new effective anti-metastatic agents, we modulated the chemical structure of the lead compound AA6, in order to find the structural determinants of activity, and to identify the cellular target responsible of the downstream anti-metastatic effects observed. New compounds synthesized were able to inhibit in vitro B16-F10 melanoma cell invasiveness, and one selected compound, CM365, showed in vivo anti-metastatic effects in a lung metastasis mouse model of melanoma. Septin-4 was identified as the most likely molecular target responsible for these effects. This study showed that CM365 is a promising molecule for metastasis prevention, remarkably effective alone or co-administered with drugs normally used in cancer therapy, such as paclitaxel.

Use of Poly Lactic-co-glycolic Acid Nano and Micro Particles in the Delivery of Drugs Modulating Different Phases of Inflammation

Chronic inflammation contributes to the pathogenesis of many diseases, including apparently unrelated conditions such as metabolic disorders, cardiovascular diseases, neurodegenerative diseases, osteoporosis, and tumors, but the use of conventional anti-inflammatory drugs to treat these diseases is generally not very effective given their adverse effects. In addition, some alternative anti-inflammatory medications, such as many natural compounds, have scarce solubility and stability, which are associated with low bioavailability. Therefore, encapsulation within nanoparticles (NPs) may represent an effective strategy to enhance the pharmacological properties of these bioactive molecules, and poly lactic-co-glycolic acid (PLGA) NPs have been widely used because of their high biocompatibility and biodegradability and possibility to finely tune erosion time, hydrophilic/hydrophobic nature, and mechanical properties by acting on the polymer's composition and preparation technique. Many studies have been focused on the use of PLGA-NPs to deliver immunosuppressive treatments for autoimmune and allergic diseases or to elicit protective immune responses, such as in vaccination and cancer immunotherapy. By contrast, this review is focused on the use of PLGA NPs in preclinical in vivo models of other diseases in which a key role is played by chronic inflammation or unbalance between the protective and reparative phases of inflammation, with a particular focus on intestinal bowel disease; cardiovascular, neurodegenerative, osteoarticular, and ocular diseases; and wound healing.

Nrf2 as a Therapeutic Target in the Resistance to Targeted Therapies in Melanoma

The use of specific inhibitors towards mutant BRAF (BRAFi) and MEK (MEKi) in BRAF-mutated patients has significantly improved progression-free and overall survival of metastatic melanoma patients. Nevertheless, half of the patients still develop resistance within the first year of therapy. Therefore, understanding the mechanisms of BRAFi/MEKi-acquired resistance has become a priority for researchers. Among others, oxidative stress-related mechanisms have emerged as a major force. The aim of this study was to evaluate the contribution of Nrf2, the master regulator of the cytoprotective and antioxidant response, in the BRAFi/MEKi acquired resistance of melanoma. Moreover, we investigated the mechanisms of its activity regulation and the possible cooperation with the oncogene YAP, which is also involved in chemoresistance. Taking advantage of established in vitro melanoma models resistant to BRAFi, MEKi, or dual resistance to BRAFi/MEKi, we demonstrated that Nrf2 was upregulated in melanoma cells resistant to targeted therapy at the post-translational level and that the deubiquitinase DUB3 participated in the control of the Nrf2 protein stability. Furthermore, we found that Nrf2 controlled the expression of YAP. Importantly, the inhibition of Nrf2, directly or through inhibition of DUB3, reverted the resistance to targeted therapies.

Surface Functionalised Parenteral Nanoemulsions for Active and Homotypic Targeting to Melanoma

Despite recent progressions in cancer genomic and immunotherapies, advanced melanoma still represents a life threat, pushing to optimise new targeted nanotechnology approaches for specific drug delivery to the tumour. To this aim, owing to their biocompatibility and favourable technological features, injectable lipid nanoemulsions were functionalised with proteins owing to two alternative approaches: transferrin was chemically grafted for active targeting, while cancer cell membrane fragments wrapping was used for homotypic targeting. In both cases, protein functionalisation was successfully achieved. Targeting efficiency was preliminarily evaluated using flow cytometry internalisation studies in two-dimensional cellular models, after fluorescence labelling of formulations with 6-coumarin. The uptake of cell-membrane-fragment-wrapped nanoemulsions was higher compared to uncoated nanoemulsions. Instead, the effect of transferrin grafting was less evident in serum-enriched medium, since such ligand probably undergoes competition with the endogenous protein. Moreover, a more pronounced internalisation was achieved when a pegylated heterodimer was employed for conjugation (p < 0.05).

Exploiting Nanomedicine for Cancer Polychemotherapy: Recent Advances and Clinical Applications

The most important limitations of chemotherapeutic agents are severe side effects and the development of multi-drug resistance. Recently, the clinical successes achieved with immunotherapy have revolutionized the treatment of several advanced-stage malignancies, but most patients do not respond and many of them develop immune-related adverse events. Loading synergistic combinations of different anti-tumor drugs in nanocarriers may enhance their efficacy and reduce life-threatening toxicities. Thereafter, nanomedicines may synergize with pharmacological, immunological, and physical combined treatments, and should be increasingly integrated in multimodal combination therapy regimens. The goal of this manuscript is to provide better understanding and key considerations for developing new combined nanomedicines and nanotheranostics. We will clarify the potential of combined nanomedicine strategies that are designed to target different steps of the cancer growth as well as its microenvironment and immunity interactions. Moreover, we will describe relevant experiments in animal models and discuss issues raised by translation in the human setting.

Parenteral Nanoemulsions Loaded with Combined Immuno- and Chemo-Therapy for Melanoma Treatment

High-grade melanoma remains a major life-threatening illness despite the improvement in therapeutic control that has been achieved by means of targeted therapies and immunotherapies in recent years. This work presents a preclinical-level test of a multi-pronged approach that includes the loading of immunotherapeutic (ICOS-Fc), targeted (sorafenib), and chemotherapeutic (temozolomide) agents within Intralipid^®, which is a biocompatible nanoemulsion with a long history of safe clinical use for total parenteral nutrition. This drug combination has been shown to inhibit tumor growth and angiogenesis with the involvement of the immune system, and a key role is played by ICOS-Fc. The inhibition of tumor growth in subcutaneous melanoma mouse models has been achieved using sub-therapeutic drug doses, which is most likely the result of the nanoemulsion's targeting properties. If translated to the human setting, this approach should therefore allow therapeutic efficacy to be achieved without increasing the risk of toxic effects.

MYC and MET cooperatively drive hepatocellular carcinoma with distinct molecular traits and vulnerabilities

Enhanced activation of the transcription factor MYC and of the receptor tyrosine kinase MET are among the events frequently occurring in hepatocellular carcinoma (HCC). Both genes individually act as drivers of liver cancer initiation and progression. However, their concomitant alteration in HCC has not been explored, nor functionally documented. Here, we analysed databases of five independent human HCC cohorts and found a subset of patients with high levels of MYC and MET (MYC^high/MET^high) characterised by poor prognosis. This clinical observation drove us to explore the functionality of MYC and MET co-occurrence in vivo, combining hydrodynamic tail vein injection for MYC expression in the R26^stopMet genetic setting, in which wild-type MET levels are enhanced following the genetic deletion of a stop cassette. Results showed that increased MYC and MET expression in hepatocytes is sufficient to induce liver tumorigenesis even in the absence of pre-existing injuries associated with a chronic disease state. Intriguingly, ectopic MYC in MET tumours increases expression of the Mki67 proliferation marker, and switches them into loss of Afp, Spp1, Gpc3, Epcam accompanied by an increase in Hgma1, Vim, and Hep-Par1 levels. We additionally found a switch in the expression of specific immune checkpoints, with an increase in the Ctla-4 and Lag3 lymphocyte co-inhibitory responses, and in the Icosl co-stimulatory responses of tumour cells. We provide in vitro evidence on the vulnerability of some human HCC cell lines to combined MYC and MET targeting, which are otherwise resistant to single inhibition. Mechanistically, combined blockage of MYC and MET converts a partial cytostatic effect, triggered by individual blockage of MYC or MET, into a cytotoxic effect. Together, these findings highlight a subgroup of HCC characterised by MYC^high/MET^high, and document functional cooperativity between MYC and MET in liver tumorigenesis. Thus, the MYC-R26^Met model is a relevant setting for HCC biology, patient classification and treatment.

Peroxisome Proliferator-Activated Receptors (PPARs) and Oxidative Stress in Physiological Conditions and in Cancer

Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor superfamily. Originally described as “orphan nuclear receptors”, they can bind both natural and synthetic ligands acting as agonists or antagonists. In humans three subtypes, PPARα, β/δ, γ, are encoded by different genes, show tissue-specific expression patterns, and contribute to the regulation of lipid and carbohydrate metabolisms, of different cell functions, including proliferation, death, differentiation, and of processes, as inflammation, angiogenesis, immune response. The PPAR ability in increasing the expression of various antioxidant genes and decreasing the synthesis of pro-inflammatory mediators, makes them be considered among the most important regulators of the cellular response to oxidative stress conditions. Based on the multiplicity of physiological effects, PPAR involvement in cancer development and progression has attracted great scientific interest with the aim to describe changes occurring in their expression in cancer cells, and to investigate the correlation with some characteristics of cancer phenotype, including increased proliferation, decreased susceptibility to apoptosis, malignancy degree and onset of resistance to anticancer drugs. This review focuses on mechanisms underlying the antioxidant and anti-inflammatory properties of PPARs in physiological conditions, and on the reported beneficial effects of PPAR activation in cancer.

Post-translational down-regulation of Nrf2 and YAP proteins, by targeting deubiquitinases, reduces growth and chemoresistance in pancreatic cancer cells

The intrinsic chemoresistance of pancreatic ductal adenocarcinoma (PDAC) represents the main obstacle in treating this aggressive malignancy. It has been observed that high antioxidant levels and upregulated Nrf2 and the YAP protein expression can be involved in PDAC chemoresistance. The mechanisms of Nrf2 and YAP increase need to be clarified. We chose a panel of PDAC cell lines with diverse sensitivity to cisplatin and gemcitabine. In PANC-1 chemoresistant cells, we found a low level of oxidative stress and high levels of Nrf2 and YAP protein expressions and their respective targets. On the contrary, in CFPAC-1 chemosensitive cells, we found high levels of oxidative stress and low level of these two proteins, as well as their respective targets. In MiaPaCa-2 cells with a middle chemoresistance, we observed intermediate features. When Nrf2 and YAP were inhibited in PANC-1 cells by Ailanthone, a plant extract, we observed a reduction of viability, thus sustaining the role of these two proteins in maintaining the PDAC chemoresistance. We then delved into the mechanisms of the Nrf2 and YAP protein upregulation in chemoresistance, discovering that it was at a post-translational level since the mRNA expressions did not match the protein levels. Treatments of PANC-1 cells with the proteasome inhibitor MG-132 and the protein synthesis inhibitor cycloheximide further confirmed this observation. The expression of DUB3 and OTUD1 deubiquitinases, involved in the control of Nrf2 and YAP protein level, respectively, was also investigated. Both protein expressions were higher in PANC-1 cells, intermediate in MiaPaCa-2 cells, and lower in CFPAC-1 cells. When DUB3 or OTUD1 were silenced, both Nrf2 and YAP expressions were downregulated. Importantly, in deubiquitinase-silenced cells, we observed a great reduction of proliferation and a higher sensitivity to gemcitabine treatment, suggesting that DUB3 and OTUD1 can represent a suitable target to overcome chemoresistance in PDAC cells.

Control of Oxidative Stress in Cancer Chemoresistance: Spotlight on Nrf2 Role

Chemoresistance represents the main obstacle to cancer treatment with both conventional and targeted therapy. Beyond specific molecular alterations, which can lead to targeted therapy, metabolic remodeling, including the control of redox status, plays an important role in cancer cell survival following therapy. Although cancer cells generally have a high basal reactive oxygen species (ROS) level, which makes them more susceptible than normal cells to a further increase of ROS, chemoresistant cancer cells become highly adapted to intrinsic or drug-induced oxidative stress by upregulating their antioxidant systems. The antioxidant response is principally mediated by the transcription factor Nrf2, which has been considered the master regulator of antioxidant and cytoprotective genes. Nrf2 expression is often increased in several types of chemoresistant cancer cells, and its expression is mediated by diverse mechanisms. In addition to Nrf2, other transcription factors and transcriptional coactivators can participate to maintain the high antioxidant levels in chemo and radio-resistant cancer cells. The control of expression and function of these molecules has been recently deepened to identify which of these could be used as a new therapeutic target in the treatment of tumors resistant to conventional therapy. In this review, we report the more recent advances in the study of Nrf2 regulation in chemoresistant cancers and the role played by other transcription factors and transcriptional coactivators in the control of antioxidant responses in chemoresistant cancer cells.

Non-Melanoma Skin Cancer: news from microbiota research

Recently, research has been deeply focusing on the role of the microbiota in numerous diseases, either affecting the skin or other organs. What it is well established is that its dysregulation promotes several cutaneous disorders (i.e. psoriasis and atopic dermatitis). To date, little is known about its composition, mediators and role in the genesis, progression and response to therapy of Non-Melanoma Skin Cancer (NMSC). Starting from a bibliographic study, we classified the selected articles into four sections: i) normal skin microbiota; ii) in vitro study models; iii) microbiota and NMSC and iv) probiotics, antibiotics and NMSC. What has emerged is how skin microflora changes, mainly represented by increases of Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa strains, modifications in the mutual quantity of β-Human papillomavirus genotypes, of Epstein Barr Virus and Malassezia or candidiasis, may contribute to the induction of a state of chronic self-maintaining inflammation, leading to cancer. In this context, the role of S. aureus and that of specific antimicrobial peptides look to be prominent. Moreover, although antibiotics may contribute to carcinogenesis, due to their ability to influence the microbiota balance, specific probiotics, such as Lacticaseibacillus rhamnosus GG, Lactobacillus johnsonii NCC 533 and Bifidobacteria spp., may be protective.

Ailanthone increases oxidative stress in CDDP-resistant ovarian and bladder cancer cells by inhibiting of Nrf2 and YAP expression through a post-translational mechanism

Chemoresistance represents one of the main obstacles in treating several types of cancer, including bladder and ovarian cancers, and it is characterized by an increase of cellular antioxidant potential. Nrf2 and YAP proteins play an important role in increasing chemoresistance and in inducing antioxidant enzymes. It has been reported that Ailanthone (Aila), a compound extracted from the Ailanthus Altissima, has an anticancer activity toward several cancer cell lines, including chemoresistant cell lines. We have examined the effect of Aila on proliferation, migration and expression of Nrf2 and YAP proteins in A2780 (CDDP-sensitive) and A2780/CP70 (CDDP-resistant) ovarian cancer cells. Furthermore, to clarify the mechanism of Aila action we extended our studies to sensitive and CDDP-resistant 253J-BV bladder cancer cells, which have been used in a previous study on the effect of Aila. Results demonstrated that Aila exerted an inhibitory effect on growth and colony formation of sensitive and CDDP-resistant ovarian cancer cells and reduced oriented cell migration with higher effectiveness in CDDP resistant cells. Moreover, Aila strongly reduced Nrf2 and YAP protein expression and reduced the expression of the Nrf2 target GSTA4, and the YAP/TEAD target survivin. In CDDP-resistant ovarian and bladder cancer cells the intracellular oxidative stress level was lower with respect to the sensitive cells. Moreover, Aila treatment further reduced the superoxide anion content of CDDP-resistant cells in correlation with the reduction of Nrf2 and YAP proteins. However, Aila treatment increased Nrf2 and YAP mRNA expression in all cancer cell lines. The inhibition of proteolysis by MG132, a proteasoma inhibitor, restored Nrf2 and YAP protein expressions, suggesting that the Aila effect was at post-translational level. In accordance with this observation, we found an increase of the Nrf2 inhibitor Keap1, a reduction of p62/SQSTM1, a Nrf2 target which leads Keap1 protein to the autophagic degradation, and a reduction of P-YAP. Moreover, UCHL1 deubiquitinase expression, which was increased in bladder and ovarian resistant cells, was down-regulated by Aila treatment. In conclusion we demonstrated that Aila can reduce proliferation and migration of cancer cells through a mechanism involving a post translational reduction of Nrf2 and YAP proteins which, in turn, entailed an increase of oxidative stress particularly in the chemoresistant lines.

Glutathione-responsive cyclodextrin-nanosponges as drug delivery systems for doxorubicin: Evaluation of toxicity and transport mechanisms in the liver

The potential mammalian hepatotoxicity of a new class of GSH-responsive cyclodextrin-based nanosponges loaded with the anticancer drug doxorubicin (Dox-GSH-NS) was investigated. Previous studies showed that these nanosponges can release medicaments preferentially in cells having high GSH content, a common feature of chemoresistant cells, and showed enhanced anti-tumoral activity compared to free Dox in vitro and in vivo in cells with high GSH content. Following these promising results, we investigated here the Dox-GSH-NS hepatotoxicity in human HepG2 cells (in vitro) and in the organotypic cultures of rat precision-cut liver slices (PCLS, ex vivo), while their accumulation in rat liver was assessed in vivo. Moreover, the transport in Dox uptake, as well as its efflux, was studied in vitro. Overall, benefiting of the integration of different investigational models, a good safety profile of Dox-GSH-NSs was evidenced, and their hepatotoxicity resulted to be comparable with respect to free Dox both in vitro and ex vivo. Furthermore, in vivo studies showed that the hepatic accumulation of the Dox loaded in the NS is comparable with respect to the free drug. In addition, Dox-GSH-NSs are taken up by active mechanisms, and can escape the efflux drug pump, thus, contributing to overcoming drug resistance.

Post-translational inhibition of YAP oncogene expression by 4-hydroxynonenal in bladder cancer cells

The transcriptional regulator YAP plays an important role in cancer progression and is negatively controlled by the Hippo pathway. YAP is frequently overexpressed in human cancers, including bladder cancer. Interestingly, YAP expression and activity can be inhibited by pro-oxidant conditions; moreover, YAP itself can also affect the cellular redox status through multiple mechanisms. 4-Hydroxynonenal (HNE), the most intensively studied end product of lipid peroxidation, is a pro-oxidant agent able to deplete GSH and has an anti-tumoral effect by affecting multiple signal pathways, including the down-regulation of oncogene expressions. These observations prompted us to investigate the effect of HNE on YAP expression and activity. We demonstrated that HNE inhibited YAP expression and its target genes in bladder cancer cells through a redox-dependent mechanism. Moreover, the YAP down-regulation was accompanied by an inhibition of proliferation, migration, invasion, and angiogenesis, as well as by an accumulation of cells in the G2/M phase of cell cycle and by an induction of apoptosis. We also established the YAP role in inhibiting cell viability and inducing apoptosis in HNE-treated cells by using an expression vector for YAP. Furthermore, we identified a post-translational mechanism for the HNE-induced YAP expression inhibition, involving an increase of YAP phosphorylation and ubiquitination, leading to proteasomal degradation. Our data established that HNE can post-translationally down-regulate YAP through a redox-dependent mechanism and that this modulation can contribute to determining the specific anti-cancer effects of HNE.

Novel tetrahydroacridine derivatives with iodobenzoic moieties induce G0/G1 cell cycle arrest and apoptosis in A549 non-small lung cancer and HT-29 colorectal cancer cells

A series of nine tetrahydroacridine derivatives with iodobenzoic moiety were synthesized and evaluated for their cytotoxic activity against cancer cell lines—A549 (human lung adenocarcinoma), HT-29 (human colorectal adenocarcinoma) and somatic cell line—EA.hy926 (human umbilical vein cell line). All compounds displayed high cytotoxicity activity against A549 (IC₅₀ 59.12–14.87 µM) and HT-29 (IC₅₀ 17.32–5.90 µM) cell lines, higher than control agents—etoposide and 5-fluorouracil. Structure–activity relationship showed that the position of iodine in the substituent in the para position and longer linker most strongly enhanced the cytotoxic effect. Among derivatives, 1i turned out to be the most cytotoxic and displayed IC₅₀ values of 14.87 µM against A549 and 5.90 µM against HT-29 cell lines. In hyaluronidase inhibition assay, all compounds presented anti-inflammatory activity, however, slightly lower than reference compound. ADMET prediction showed that almost all compounds had good pharmacokinetic profiles. 1b, 1c and 1f compounds turned out to act against chemoresistance in cisplatin-resistant 253J B-V cells. Compounds intercalated into DNA and inhibited cell cycle in G0/G1 phase—the strongest inhibition was observed for 1i in A549 and 1c in HT-29. Among compounds, the highest apoptotic effect in both cell lines was observed after treatment with 1i. Compounds caused DNA damage and H2AX phosphorylation, which was detected in A549 and HT-29 cells. All research confirmed anticancer properties of novel tetrahydroacridine derivatives and explained a few pathways of their mechanism of cytotoxic action.

Paclitaxel-Loaded Nanosponges Inhibit Growth and Angiogenesis in Melanoma Cell Models

This study investigated the effects of free paclitaxel (PTX) and PTX-loaded in pyromellitic nanosponges (PTX-PNS) in reducing in vitro and in vivo melanoma cell growth and invasivity, and in inhibiting angiogenesis. To test the response of cells to the two PTX formulations, the cell viability was evaluated by MTT assay in seven continuous cell lines, in primary melanoma cells, both in 2D and 3D cultures, and in human umbilical vein endothelial cells (HUVECs) after exposure to different concentrations of PTX or PTX-PNS. Cell motility was assessed by a scratch assay or Boyden chamber assay, evaluating cell migration in presence or absence of diverse concentrations of PTX or PTX-PNS. The effect of PTX and PTX-PNS on angiogenesis was evaluated as endothelial tube formation assay, a test able to estimate the formation of three-dimensional vessels in vitro. To assess the anticancer effect of PTX and PTX-PNS in in vivo experiments, the two drug formulations were tested in a melanoma mouse model obtained by B16-BL6 cell implantation in C57/BL6 mice. Results obtained were as follows: 1) MTT analysis revealed that cell proliferation was more affected by PTX-PNS than by PTX in all tested cell lines, in both 2D and 3D cultures; 2) the analysis of the cell migration showed that PTX-PNS acted at very lower concentrations than PTX; 3) tube formation assay showed that PTX-PNS were more effective in inhibiting tube formation than free PTX; and 4) in vivo experiments demonstrated that tumor weights, volumes, and growth were significantly reduced by PTX-PNS treatment with respect to PTX; the angiogenesis and the cell proliferation, detected in the tumor samples with CD31 and Ki-67 antibodies, respectively, indicated that, in the PTX-PNS-treated tumors, the tube formation was inhibited, and a low amount of proliferating cells was present. Taken together, our data demonstrated that our new PTX nanoformulation can respond to some important issues related to PTX treatment, lowering the anti-tumor effective doses and increasing the effectiveness in inhibiting melanoma growth in vivo.

Low-dose curcuminoid-loaded in dextran nanobubbles can prevent metastatic spreading in prostate cancer cells

Preventing recurrences and metastasis of prostate cancer after prostatectomy by administering adjuvant therapies is quite a controversial issue. In addition to effectiveness, absence of side effects and long term toxicity are mandatory. Curcuminoids (Curc) extracted with innovative techniques and effectively loaded by polymeric nanobubbles (Curc-NBs) satisfy such requirements. Curc-NBs showed stable over 30 d, were effectively internalized by tumor cells and were able to slowly release Curc in a sustained way. Significant biological effects were detected in PC-3 and DU-145 cell lines where Curc-NBs were able to inhibit adhesion and migration, to promote cell apoptosis and to affect cell viability and colony-forming capacity in a dose-dependent manner. Since the favourable effects are already detectable at very low doses, which can be reached at a clinical level, the actual drug concentration can be visualized and monitored by US or MRI, Curc-NBs can be proposed as an effective adjuvant theranostic tool.

Ailanthone inhibits cell growth and migration of cisplatin resistant bladder cancer cells through down-regulation of Nrf2, YAP, and c-Myc expression

BACKGROUND

Ailanthone (Aila) is a natural active compound isolated from the Ailanthus altissima, which has been shown to possess an "in vitro" growth-inhibitory effect against several cancer cell lines. Advanced bladder cancer is a common disease characterized by a frequent onset of resistance to cisplatin-based therapy. The cisplatin (CDDP) resistance is accompanied by an increase in Nrf2 protein expression which contributes to conferring resistance. Recently, we demonstrated a cross-talk between Nrf2 and YAP. YAP has also been demonstrated to play an important role in chemoresistance of bladder cancer.

PURPOSE

We analyzed the antitumor effect of Aila in sensitive and CDDP-resistant bladder cancer cells and the molecular mechanisms involved in Aila activity.

STUDY DESIGN

Sensitive and CDDP-resistant 253J B-V and 253J bladder cancer cells, intrinsically CDDP-resistant T24 bladder cancer cells and HK-2 human renal cortex cells were used. Cells were treated with diverse concentrations of Aila and proliferation, cell cycle, apoptosis and gene expressions were determined.

METHODS

Aila toxicity and proliferation were determined by MTT and colony forming methods, respectively. Cell cycle was determined by cytofluorimetric analysis through PI staining method. Apoptosis was detected using Annexin V and PI double staining followed by quantitative flow cytometry. Expressions of Nrf2, Yap, c-Myc, and house-keeping genes were determined by western blot with specific antibodies. Cell migration was detected by wound healing and Boyden chamber analysis.

RESULTS

Aila inhibited the growth of sensitive and CDDP-resistant bladder cancer cells with the same effectiveness. On the contrary, the growth of HK-2 cells was only slightly reduced by Aila. Cell cycle analysis revealed an accumulation of Aila-treated bladder cancer cells in the G0/G1 phase. Interestingly, Aila strongly reduced Nrf2 expression in these cell lines. Moreover, Aila significantly reduced YAP, and c-Myc protein expression. The random and the oriented migration of bladder cancer cells were strongly inhibited by Aila treatment, in particular in CDDP-resistant cells.

CONCLUSION

Aila inhibited proliferation and invasiveness of bladder cancer cells. Its high effectiveness in CDDP resistant cells could be related to the inhibition of Nrf2, YAP, and c-Myc expressions. Aila could represent a new tool to treating CDDP-resistant bladder cancers.

Nasal cytology: Methodology with application to clinical practice and research

Nasal cytology is an easy, cheap, non-invasive and point-of-care method to assess nasal inflammation and disease-specific cellular features. By means of nasal cytology, it is possible to distinguish between different inflammatory patterns that are typically associated with specific diseases (ie, allergic and non-allergic rhinitis). Its use is particularly relevant when other clinical information, such as signs, symptoms, time-course and allergic sensitizations, is not enough to recognize which of the different rhinitis phenotypes is involved; for example, it is only by means of nasal cytology that it is possible to distinguish, among the non-allergic rhinitis, those characterized by eosinophilic (NARES), mast cellular (NARMA), mixed eosinophilic-mast cellular (NARESMA) or neutrophilic (NARNE) inflammation. Despite its clinical usefulness, cheapness, non-invasiveness and easiness, nasal cytology is still underused and this is at least partially due to the fact that, as far as now, there is not a consensus or an official recommendation on its methodological issues. We here review the scientific literature about nasal cytology, giving recommendations on how to perform and interpret nasal cytology.

Drug Delivery Nanoparticles in Treating Chemoresistant Tumor Cells

Intrinsic or acquired chemoresistance represents the main obstacle to the successful treatment of cancer patients. Several mechanisms are involved in multidrug resistance: decreased uptake of hydrophilic drugs, increase of energy dependent efflux, alteration of the redox state, alteration of apoptotic pathways, and modification of the tumor microenvironment. In recent years, several types of nanoparticles have been developed to overcome these obstacles and improve the accumulation and release of drugs at the pathological site. In this review, we describe the main mechanisms involved in multidrug resistance and the nanovehicles which have been proposed to target specific aspects of this phenomenon.

Crosstalk between Nrf2 and YAP contributes to maintaining the antioxidant potential and chemoresistance in bladder cancer

Redox adaptation plays an important role in cancer cells drug resistance. The antioxidant response is principally mediated by the transcription factor Nrf2, that induces the transcriptional activation of several genes involved in GSH synthesis, chemoresistance, and cytoprotection. YAP is emerging as a key mediator of chemoresistance in a variety of cancers, but its role in controlling the antioxidant status of the cells is yet elusive. Here, we show that impairing YAP protein expression reduced GSH content and Nrf2 protein and mRNA expression in bladder cancer cells. Moreover, in YAP knocked down cells the expression of FOXM1, a transcription factor involved in Nrf2 transcription, was down-regulated and the silencing of FOXM1 reduced Nrf2 expression. On the other hand, the silencing of Nrf2, as well as the depletion of GSH by BSO treatment, inhibited YAP expression, suggesting that cross-talk exists between YAP and Nrf2 proteins. Importantly, we found that silencing either YAP or Nrf2 enhanced sensitivity of bladder cancer cells to cytotoxic agents and reduced their migration. Furthermore, the inhibition of both YAP and Nrf2 expressions significantly increased cytotoxic drug sensitivity and synergistically reduced the migration of chemoresistant bladder cancer cells. These findings provide a rationale for targeting these transcriptional regulators in patients with chemoresistant bladder cancer, expressing high YAP and bearing a proficient antioxidant system.

KRIT1 loss-of-function induces a chronic Nrf2-mediated adaptive homeostasis that sensitizes cells to oxidative stress: Implication for Cerebral Cavernous Malformation disease

KRIT1 (CCM1) is a disease gene responsible for Cerebral Cavernous Malformations (CCM), a major cerebrovascular disease of proven genetic origin affecting 0.3-0.5% of the population. Previously, we demonstrated that KRIT1 loss-of-function is associated with altered redox homeostasis and abnormal activation of the redox-sensitive transcription factor c-Jun, which collectively result in pro-oxidative, pro-inflammatory and pro-angiogenic effects, suggesting a novel pathogenic mechanism for CCM disease and raising the possibility that KRIT1 loss-of-function exerts pleiotropic effects on multiple redox-sensitive mechanisms. To address this possibility, we investigated major redox-sensitive pathways and enzymatic systems that play critical roles in fundamental cytoprotective mechanisms of adaptive responses to oxidative stress, including the master Nrf2 antioxidant defense pathway and its downstream target Glyoxalase 1 (Glo1), a pivotal stress-responsive defense enzyme involved in cellular protection against glycative and oxidative stress through the metabolism of methylglyoxal (MG). This is a potent post-translational protein modifier that may either contribute to increased oxidative molecular damage and cellular susceptibility to apoptosis, or enhance the activity of major apoptosis-protective proteins, including heat shock proteins (Hsps), promoting cell survival. Experimental outcomes showed that KRIT1 loss-of-function induces a redox-sensitive sustained upregulation of Nrf2 and Glo1, and a drop in intracellular levels of MG-modified Hsp70 and Hsp27 proteins, leading to a chronic adaptive redox homeostasis that counteracts intrinsic oxidative stress but increases susceptibility to oxidative DNA damage and apoptosis, sensitizing cells to further oxidative challenges. While supporting and extending the pleiotropic functions of KRIT1, these findings shed new light on the mechanistic relationship between KRIT1 loss-of-function and enhanced cell predisposition to oxidative damage, thus providing valuable new insights into CCM pathogenesis and novel options for the development of preventive and therapeutic strategies.

Enhanced cytotoxic effect of camptothecin nanosponges in anaplastic thyroid cancer cells in vitro and in vivo on orthotopic xenograft tumors

Anaplastic carcinoma of the thyroid (ATC) is a lethal human malignant cancer with median survival of 6 months. To date, no treatment has substantially changed its course, which makes urgent need for the development of novel drugs or novel formulations for drug delivery. Nanomedicine has enormous potential to improve the accuracy of cancer therapy by enhancing availability and stability, decreasing effective doses and reducing side effects of drugs. Camptothecin (CPT) is an inhibitor of DNA topoisomerase-I with several anticancer properties but has poor solubility and a high degradation rate. Previously, we reported that CPT encapsulated in β-cyclodextrin-nanosponges (CN-CPT) increased solubility, was protected from degradation and inhibited the growth of prostate tumor cells both in vitro and in vivo. The aim of this study was to extend that work by assessing the CN-CPT effectiveness on ATC both in vitro and in vivo. Results showed that CN-CPT significantly inhibited viability, clonogenic capacity and cell-cycle progression of ATC cell lines showing a faster and enhanced effect compared to free CPT. Moreover, CN-CPT inhibited tumor cell adhesion to vascular endothelial cells, migration, secretion of pro-angiogenic factors (IL-8 and VEGF-α), expression of β-PIX, belonging to the Rho family activators, and phosphorylation of the Erk1/2 MAPK. Finally, CN-CPT significantly inhibited the growth, the metastatization and the vascularization of orthotopic ATC xenografts in SCID/beige mice without apparent toxic effects in vivo. This work extends the previous insight showing that β-cyclodextrin-nanosponges are a promising tool for the treatment of ATC.

DNA damage by lipid peroxidation products: implications in cancer, inflammation and autoimmunity

Oxidative stress and lipid peroxidation (LPO) induced by inflammation, excess metal storage and excess caloric intake cause generalized DNA damage, producing genotoxic and mutagenic effects. The consequent deregulation of cell homeostasis is implicated in the pathogenesis of a number of malignancies and degenerative diseases. Reactive aldehydes produced by LPO, such as malondialdehyde, acrolein, crotonaldehyde and 4-hydroxy-2-nonenal, react with DNA bases, generating promutagenic exocyclic DNA adducts, which likely contribute to the mutagenic and carcinogenic effects associated with oxidative stress-induced LPO. However, reactive aldehydes, when added to tumor cells, can exert an anticancerous effect. They act, analogously to other chemotherapeutic drugs, by forming DNA adducts and, in this way, they drive the tumor cells toward apoptosis. The aldehyde-DNA adducts, which can be observed during inflammation, play an important role by inducing epigenetic changes which, in turn, can modulate the inflammatory process. The pathogenic role of the adducts formed by the products of LPO with biological macromolecules in the breaking of immunological tolerance to self antigens and in the development of autoimmunity has been supported by a wealth of evidence. The instrumental role of the adducts of reactive LPO products with self protein antigens in the sensitization of autoreactive cells to the respective unmodified proteins and in the intermolecular spreading of the autoimmune responses to aldehyde-modified and native DNA is well documented. In contrast, further investigation is required in order to establish whether the formation of adducts of LPO products with DNA might incite substantial immune responsivity and might be instrumental for the spreading of the immunological responses from aldehyde-modified DNA to native DNA and similarly modified, unmodified and/or structurally analogous self protein antigens, thus leading to autoimmunity.

GSH-targeted nanosponges increase doxorubicin-induced toxicity "in vitro" and "in vivo" in cancer cells with high antioxidant defenses

Several reports indicate that chemo-resistant cancer cells become highly adapted to intrinsic oxidative stress by up-regulating their antioxidant systems, which causes an increase of intracellular GSH content. Doxorubicin is one of the most widely used drugs for tumor treatment, able to kill cancer cells through several mechanisms. However, doxorubicin use is limited by its toxicity and cancer resistance. Therefore, new therapeutic strategies able to reduce doses and to overcome chemo-resistance are needed. A new class of glutathione-responsive cyclodextrin nanosponges (GSH-NS), is able to release anticancer drugs preferentially in cells having high GSH content. Doxorubicin-loaded GSH-NS, in the cancer cells with high GSH content, inhibited clonogenic growth, cell viability, topoisomerase II activity and induced DNA damage with higher effectiveness than free drug. Moreover, GSH-NS reduced the development of human tumor in xenograft models more than free drug. These characteristics indicate that GSH-NS can be a suitable drug delivery carrier for future applications in cancer therapy.

In Vitro and In Vivo Therapeutic Evaluation of Camptothecin-Encapsulated β-Cyclodextrin Nanosponges in Prostate Cancer

Camptothecin (CPT), a pentacyclic alkaloid, is an inhibitor of DNA Topoisomerase-I and shows a wide spectrum of anti-cancer activities. The use of CPT has been hampered by poor aqueous solubility and a high degradation rate. Previously, it has been reported that CPT encapsulated in β-cyclodextrin-nanosponges (CN-CPT) overcomes these disadvantages and improves the CPT's inhibitory effect on DU145 prostate tumor cell lines, and PC-3 growth in vitro. This work extends these observations by showing that CN-CPT significantly inhibits the adhesion and migration of these tumor cells and their STAT3 phosphorylation. The anti-adhesive effect is exerted also in human endothelial cells, in which CN-CPT also inhibits the angiogenic activity as assessed by the tubulogenesis and sprouting assays. Finally, CN-CPT substantially delays the growth of PC-3 cell engraftment in SCID mice in vivo without apparent toxic effects. These results support the use of β-cyclodextrin nanosponge nanotechnology as a potential nanocarrier for delivery of anticancer drugs in the treatment of prostate cancers.

Mitochondrial Dysfunction in Cancer and Neurodegenerative Diseases: Spotlight on Fatty Acid Oxidation and Lipoperoxidation Products

In several human diseases, such as cancer and neurodegenerative diseases, the levels of reactive oxygen species (ROS), produced mainly by mitochondrial oxidative phosphorylation, is increased. In cancer cells, the increase of ROS production has been associated with mtDNA mutations that, in turn, seem to be functional in the alterations of the bioenergetics and the biosynthetic state of cancer cells. Moreover, ROS overproduction can enhance the peroxidation of fatty acids in mitochondrial membranes. In particular, the peroxidation of mitochondrial phospholipid cardiolipin leads to the formation of reactive aldehydes, such as 4-hydroxynonenal (HNE) and malondialdehyde (MDA), which are able to react with proteins and DNA. Covalent modifications of mitochondrial proteins by the products of lipid peroxidation (LPO) in the course of oxidative cell stress are involved in the mitochondrial dysfunctions observed in cancer and neurodegenerative diseases. Such modifications appear to affect negatively mitochondrial integrity and function, in particular energy metabolism, adenosine triphosphate (ATP) production, antioxidant defenses and stress responses. In neurodegenerative diseases, indirect confirmation for the pathogenetic relevance of LPO-dependent modifications of mitochondrial proteins comes from the disease phenotypes associated with their genetic alterations.

Immunotargeting of Antigen xCT Attenuates Stem-like Cell Behavior and Metastatic Progression in Breast Cancer

Resistance to therapy and lack of curative treatments for metastatic breast cancer suggest that current therapies may be missing the subpopulation of chemoresistant and radioresistant cancer stem cells (CSC). The ultimate success of any treatment may well rest on CSC eradication, but specific anti-CSC therapies are still limited. A comparison of the transcriptional profiles of murine Her2(+) breast tumor TUBO cells and their derived CSC-enriched tumorspheres has identified xCT, the functional subunit of the cystine/glutamate antiporter system xc(-), as a surface protein that is upregulated specifically in tumorspheres. We validated this finding by cytofluorimetric analysis and immunofluorescence in TUBO-derived tumorspheres and in a panel of mouse and human triple negative breast cancer cell-derived tumorspheres. We further show that downregulation of xCT impaired tumorsphere generation and altered CSC intracellular redox balance in vitro, suggesting that xCT plays a functional role in CSC biology. DNA vaccination based immunotargeting of xCT in mice challenged with syngeneic tumorsphere-derived cells delayed established subcutaneous tumor growth and strongly impaired pulmonary metastasis formation by generating anti-xCT antibodies able to alter CSC self-renewal and redox balance. Finally, anti-xCT vaccination increased CSC chemosensitivity to doxorubicin in vivo, indicating that xCT immunotargeting may be an effective adjuvant to chemotherapy.

YAP activation protects urothelial cell carcinoma from treatment-induced DNA damage

Current standard of care for muscle-invasive urothelial cell carcinoma (UCC) is surgery along with perioperative platinum-based chemotherapy. UCC is sensitive to cisplatin-based regimens, but acquired resistance eventually occurs, and a subset of tumors is intrinsically resistant. Thus, there is an unmet need for new therapeutic approaches to target chemotherapy-resistant UCC. Yes-associated protein (YAP) is a transcriptional co-activator that has been associated with bladder cancer progression and cisplatin resistance in ovarian cancer. In contrast, YAP has been shown to induce DNA damage associated apoptosis in non-small cell lung carcinoma. However, no data have been reported on the YAP role in UCC chemo-resistance. Thus, we have investigated the potential dichotomous role of YAP in UCC response to chemotherapy utilizing two patient-derived xenograft models recently established. Constitutive expression and activation of YAP inversely correlated with in vitro and in vivo cisplatin sensitivity. YAP overexpression protected while YAP knock-down sensitized UCC cells to chemotherapy and radiation effects via increased accumulation of DNA damage and apoptosis. Furthermore, pharmacological YAP inhibition with verteporfin inhibited tumor cell proliferation and restored sensitivity to cisplatin. In addition, nuclear YAP expression was associated with poor outcome in UCC patients who received perioperative chemotherapy. In conclusion, these results suggest that YAP activation exerts a protective role and represents a pharmacological target to enhance the anti-tumor effects of DNA damaging modalities in the treatment of UCC.

Role of 4-hydroxynonenal-protein adducts in human diseases

SIGNIFICANCE

Oxidative stress provokes the peroxidation of polyunsaturated fatty acids in cellular membranes, leading to the formation of aldheydes that, due to their high chemical reactivity, are considered to act as second messengers of oxidative stress. Among the aldehydes formed during lipid peroxidation (LPO), 4-hydroxy-2-nonenal (HNE) is produced at a high level and easily reacts with both low-molecular-weight compounds and macromolecules, such as proteins and DNA. In particular, HNE-protein adducts have been extensively investigated in diseases characterized by the pathogenic contribution of oxidative stress, such as cancer, neurodegenerative, chronic inflammatory, and autoimmune diseases.

RECENT ADVANCES

In this review, we describe and discuss recent insights regarding the role played by covalent adducts of HNE with proteins in the development and evolution of those among the earlier mentioned disease conditions in which the functional consequences of their formation have been characterized.

CRITICAL ISSUES

Results obtained in recent years have shown that the generation of HNE-protein adducts can play important pathogenic roles in several diseases. However, in some cases, the generation of HNE-protein adducts can represent a contrast to the progression of disease or can promote adaptive cell responses, demonstrating that HNE is not only a toxic product of LPO but also a regulatory molecule that is involved in several biochemical pathways.

FUTURE DIRECTIONS

In the next few years, the refinement of proteomical techniques, allowing the individuation of novel cellular targets of HNE, will lead to a better understanding the role of HNE in human diseases.

Combination strategy targeting VEGF and HGF/c-met in human renal cell carcinoma models

Alternative pathways to the VEGF, such as hepatocyte growth factor or HGF/c-met, are emerging as key players in tumor angiogenesis and resistance to anti-VEGF therapies. The aim of this study was to assess the effects of a combination strategy targeting the VEGF and c-met pathways in clear cell renal cell carcinoma (ccRCC) models. Male SCID mice (8/group) were implanted with 786-O tumor pieces and treated with either a selective VEGF receptor tyrosine kinase inhibitor, axitinib (36 mg/kg, 2×/day); a c-met inhibitor, crizotinib (25 mg/kg, 1×/day); or combination. We further tested this drug combination in a human ccRCC patient-derived xenograft, RP-R-01, in both VEGF-targeted therapy-sensitive and -resistant models. To evaluate the resistant phenotype, we established an RP-R-01 sunitinib-resistant model by continuous sunitinib treatment (60 mg/kg, 1×/day) of RP-R-01-bearing mice. Treatment with single-agent crizotinib reduced tumor vascularization but failed to inhibit tumor growth in either model, despite also a significant increase of c-met expression and phosphorylation in the sunitinib-resistant tumors. In contrast, axitinib treatment was effective in inhibiting angiogenesis and tumor growth in both models, with its antitumor effect significantly increased by the combined treatment with crizotinib, independently from c-met expression. Combination treatment also induced prolonged survival and significant tumor growth inhibition in the 786-O human RCC model. Overall, our results support the rationale for the clinical testing of combined VEGF and HGF/c-met pathway blockade in the treatment of ccRCC, both in first- and second-line setting.

Abstract 3754: Hippo pathway effector Yes-associated protein and cisplatin resistance in transitional cell carcinoma of the bladder

Background: Transitional cell carcinoma of the bladder (TCC) arises from the cells lining the bladder and accounts for 90% of bladder cancers. Current standard of care for muscle-invasive TCC is surgery with perioperative cisplatin-based chemotherapy regimens. Some tumors are quite sensitive to cisplatin but others either acquire resistance or are refractory. A reduced drug availability, an increased efficacy of the DNA damage repair machinery or defects in the apoptotic process are the main mechanisms involved in cisplatin resistance. The Hippo tumor suppressor pathway controls multiple cellular functions that are important for tumorigenesis and drug-resistance, including proliferation, apoptosis and oxidative stress regulation. Specifically, the overexpression of Yes-associated protein (YAP), one of the two repressed-targets of this pathway, prevents tumor necrosis factor-induced apoptosis in mouse liver and protects cancer cells from chemotherapy-induced apoptosis. Intriguingly, this transcriptional co-activator has been shown to be involved in bladder cancer progression and to be a biomarker for poor prognosis of patients with TCC. Furthermore, in ovarian cancer, YAP has been shown to confer resistance to cisplatin. Thus, we hypothesized that YAP may be involved in cisplatin resistance in bladder cancer and could predict drug response in TCC patients. Methods: Cisplatin activity and YAP protein expression and localization were analyzed in different in vitro and in vivo models of TCC: 1) Collection of bladder cancer cell lines, genetically manipulated by knocking-down or overexpressing YAP; 2) Cell line models of cisplatin resistance, obtained by long term continuous in vitro exposure to increasing drug concentrations; 3) Two TCC patient derived xenograft (PDX) models and derived primary cells (RP-B-01 and RP-B-02) with different intrinsic sensitivity to cisplatin. Furthermore, by continuous in vivo cisplatin treatment (2.5 to 5 mg/Kg, 1x/week, i.p.), we are currently establishing a cisplatin resistant RP-B-02 model. In vitro cisplatin effect was evaluated in apoptosis, proliferation and colony formation assays. Results: YAP expression and nuclear localization was inversely correlated with cisplatin sensitivity in TCC cell lines. Cisplatin-resistant TCC cell lines expressed higher YAP than parental counterparts. Cisplatin-induced apoptosis was significantly increased by YAP knockdown in T24 cell line. In vivo cisplatin treatment showed a greater anti-tumor effect in the low YAP-expressing RP-B-02 model as compared to the high YAP-expressing RP-B-01 tumors. Expression of YAP in human TCC specimens will be also presented. Summary: Overall, these data suggest that YAP has a role in bladder cancer response to cisplatin and highlights the potential therapeutic application of YAP as a biomarker of cisplatin sensitivity in TCC patients.

Citation Format: Eric Stefano Ciamporcero, He Shen, Sreenivasulu Chintala, Swathi Ramakrishnan, Sheng Yu Ku, Kiersten M. Miles, Stefania Pizzimenti, Candace Johnson, Jianmin Zhang, Giuseppina Barrera, Roberto Pili. Hippo pathway effector Yes-associated protein and cisplatin resistance in transitional cell carcinoma of the bladder. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3754. doi:10.1158/1538-7445.AM2014-3754

Italian study on buckwheat allergy: prevalence and clinical features of buckwheat-sensitized patients in Italy

Buckwheat allergy is considered a rare food allergy outside of Asia. In Europe, buckwheat has been described mainly as a hidden allergen. Data on the prevalence of buckwheat hypersensitivity in non-Asian countries is very poor. The aim of this multicenter study was to evaluate the prevalence of buckwheat sensitization and its association with other sensitizations among patients referred to allergy clinics in different geographic areas of Italy. All patients referred to 18 Italian allergy clinics from February through April 2011 were included in the study and evaluated for sensitization to buckwheat and other allergens depending on their clinical history. A total of 1,954 patients were included in the study and 61.3 percent of them were atopic. Mean prevalence of buckwheat sensitization was 3.6 percent with significant difference between Northern (4.5 percent), Central (2.2 percent) and Southern (2.8 percent) regions. This is, to our knowledge, the largest epidemiological survey on buckwheat allergy reported outside of Asia. Buckwheat is an emerging allergen in Italy, being more frequently associated to sensitization in Northern regions.

The inclusion complex of 4-hydroxynonenal with a polymeric derivative of β-cyclodextrin enhances the antitumoral efficacy of the aldehyde in several tumor cell lines and in a three-dimensional human melanoma model

4-Hydroxynonenal (HNE) is the most studied end product of the lipoperoxidation process, by virtue of its relevant biological activity. The antiproliferative and proapoptotic effects of HNE have been widely demonstrated in a great variety of tumor cell types in vitro. Thus, it might represent a promising new molecule in anticancer therapy strategies. However, the extreme reactivity of this aldehyde, as well as its insolubility in water, a limiting factor for drug bioavailability, and its rapid degradation by specific enzymes represent major obstacles to its possible in vivo application. Various strategies can used to overcome these problems. One of the most attractive strategies is the use of nanovehicles, because loading drugs into nanosized structures enhances their stability and solubility, thus improving their bioavailability and their antitumoral effectiveness. Several natural or synthetic polymers have been used to synthesize nanosized structures and, among them, β-cyclodextrin (βCD) polymers are playing a very important role in drug formulation by virtue of the ability of βCD to form inclusion compounds with a wide range of solid and liquid molecules by molecular complexation. Moreover, several βCD derivatives have been designed to improve their physicochemical properties and inclusion capacities. Here we report that the inclusion complex of HNE with a derivative of βCD, the βCD-poly(4-acryloylmorpholine) conjugate (PACM-βCD), enhances the aldehyde stability. Moreover, the inclusion of HNE in PACM-βCD potentiates its antitumor effects in several tumor cell lines and in a more complex system, such as a human reconstructed skin carrying melanoma tumor cells.

Interaction of aldehydes derived from lipid peroxidation and membrane proteins

A great variety of compounds are formed during lipid peroxidation of polyunsaturated fatty acids of membrane phospholipids. Among them, bioactive aldehydes, such as 4-hydroxyalkenals, malondialdehyde (MDA) and acrolein, have received particular attention since they have been considered as toxic messengers that can propagate and amplify oxidative injury. In the 4-hydroxyalkenal class, 4-hydroxy-2-nonenal (HNE) is the most intensively studied aldehyde, in relation not only to its toxic function, but also to its physiological role. Indeed, HNE can be found at low concentrations in human tissues and plasma and participates in the control of biological processes, such as signal transduction, cell proliferation, and differentiation. Moreover, at low doses, HNE exerts an anti-cancer effect, by inhibiting cell proliferation, angiogenesis, cell adhesion and by inducing differentiation and/or apoptosis in various tumor cell lines. It is very likely that a substantial fraction of the effects observed in cellular responses, induced by HNE and related aldehydes, be mediated by their interaction with proteins, resulting in the formation of covalent adducts or in the modulation of their expression and/or activity. In this review we focus on membrane proteins affected by lipid peroxidation-derived aldehydes, under physiological and pathological conditions.

Abstract 1618: Combination of axitinib and crizotinib in renal cell carcinoma models

Background: The vascular endothelium growth factor (VEGF) pathway plays a pivotal role in angiogenesis. Axitinib (AG-013736), a potent small molecule receptor tyrosine kinase inhibitor highly selective for VEGF receptor 1, 2 and 3, is currently being tested in Phase II/III clinical trials for the treatment of solid tumors and has been approved as a second-line treatment for renal cell carcinoma (RCC). The hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (c-Met) pathway has also been shown to play an important role in tumor vascularization, as well as epithelial to mesenchymal transition (EMT), metastatization, and acquired resistance. Crizotinib (PF-02341066), a potent and selective inhibitor of anaplastic lymphoma kinase (ALK) and c-Met kinase, has been approved for the treatment of advanced ALK-positive non-small cell lung cancer. The aim of this study was to assess the combinational effect of axitinib and crizotinib in two models of RCC with differing degrees of c-Met expression and sensitivity to anti-angiogenic agents. We hypothesized that the combination would provide greater anti-tumor and anti-angiogenesis efficacy compared to single-agents. Methods: Human high c-Met expressing 786-O and low c-Met expressing RP-01 (developed from a skin metastasis of a patient with sporadic clear cell RCC) xenografts were inoculated into SCID mice (8/group). After approximately 6 weeks of tumor growth, mice were treated with vehicle, axitinib (36 mg/kg, 2x/day, oral gavage), crizotinib (25 mg/kg, 1x/day, oral gavage), or axitinib plus crizotinib. Once tumor volume of vehicle mice reached 200 mm2, mice were sacrificed and tumor tissue was excised and analyzed. A sunitinib-resistant RP-01 model was also developed through continued in vivo exposure to sunitinib (60 mg/kg, 1x/day, oral gavage) to further test the different responses to treatments and to evaluate the possible role of c-Met in sunitinib resistance. Compounds were kindly provided by Pfizer. Results: We observed that single-agent crizotinib anti-tumoral activity was strongly related to c-Met expression, inhibiting 786-O tumor growth in vivo, but not RP-01. More interestingly, significant synergistic effects were found with crizotinib and axitinib, whereby enhanced inhibition of 786-O xenograft tumor growth was found (from 17%, axitinib, to 76% combination, p &lt;0.05 of combination vs. both single agents). No overt signs of toxicity were observed in any of the experimental groups. Vessel density, pericyte coverage (CD31 and NG2), and EMT markers are being evaluated with immunohistochemistry. Results from combination treatment in the sunitinib-resistant model will be presented. Summary: Overall, the data demonstrate that this combination therapy resulted in significant anti-tumor activity in a high c-Met expressing RCC model, highlighting the potential therapeutic application of combined VEGF and c-Met blockade in the treatment of RCC.

Citation Format: Eric S. Ciamporcero, Kiersten M. Miles, Remi Adelaiye, Stefania Pizzimenti, Giuseppina Barrera, Roberto Pili. Combination of axitinib and crizotinib in renal cell carcinoma models. [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 1618. doi:10.1158/1538-7445.AM2013-1618

Rosiglitazone and AS601245 decrease cell adhesion and migration through modulation of specific gene expression in human colon cancer cells

PPARs are nuclear receptors activated by ligands. Activation of PPARγ leads to a reduction of adhesion and motility in some cancer models. PPARγ transcriptional activity can be negatively regulated by JNK-mediated phosphorylation. We postulated that the use of agents able to inhibit JNK activity could increase the effectiveness of PPARγ ligands. We analysed the effects of rosiglitazone (PPARγ ligand) and AS601245 (a selective JNK inhibitor) alone or in association on adhesion and migration of CaCo-2, HT29, and SW480 human colon cancer cells and investigated, through microarray analysis, the genes involved in these processes. Cell adhesion and migration was strongly inhibited by rosiglitazone and AS601245. Combined treatment with the two compounds resulted in a greater reduction of the adhesion and migration capacity. Affymetrix analysis in CaCo-2 cells revealed that some genes which were highly modulated by the combined treatment could be involved in these biological responses. Rosiglitazone, AS601245 and combined treatment down-regulated the expression of fibrinogen chains in all three cell lines. Moreover, rosiglitazone, alone or in association with AS601245, caused a decrease in the fibrinogen release. ARHGEF7/β-PIX gene was highly down-regulated by combined treatment, and western blot analysis revealed that β-PIX protein is down-modulated in CaCo-2, HT29 and SW480 cells, also. Transfection of cells with β-PIX gene completely abrogated the inhibitory effect on cell migration, determined by rosiglitazone, AS601245 and combined treatment. Results demonstrated that β-PIX protein is involved in the inhibition of cell migration and sustaining the positive interaction between PPARγ ligands and anti-inflammatory agents in humans.

AS601245, an Anti-Inflammatory JNK Inhibitor, and Clofibrate Have a Synergistic Effect in Inducing Cell Responses and in Affecting the Gene Expression Profile in CaCo-2 Colon Cancer Cells

PPARαs are nuclear receptors highly expressed in colon cells. They can be activated by the fibrates (clofibrate, ciprofibrate etc.) used to treat hyperlipidemia. Since PPARα transcriptional activity can be negatively regulated by JNK, the inhibition of JNK activity could increase the effectiveness of PPARα ligands. We analysed the effects of AS601245 (a JNK inhibitor) and clofibrate alone or in association, on proliferation, apoptosis, differentiation and the gene expression profile of CaCo-2 human colon cancer cells. Proliferation was inhibited in a dose-dependent way by clofibrate and AS601245. Combined treatment synergistically reduced cell proliferation, cyclin D1 and PCNA expression and induced apoptosis and differentiation. Reduction of cell proliferation, accompanied by the modulation of p21 expression was observed in HepG2 cells, also. Gene expression analysis revealed that some genes were highly modulated by the combined treatment and 28 genes containing PPRE were up-regulated, while clofibrate alone was ineffective. Moreover, STAT3 signalling was strongly reduced by combined treatment. After combined treatment, the binding of PPARα to PPRE increased and paralleled with the expression of the PPAR coactivator MED1. Results demonstrate that combined treatment increases the effectiveness of both compounds and suggest a positive interaction between PPARα ligands and anti-inflammatory agents in humans.

Nuclear factor erythroid 2-related factor-2 activity controls 4-hydroxynonenal metabolism and activity in prostate cancer cells

4-Hydroxynonenal (HNE) is an end product of lipoperoxidation with antiproliferative and proapoptotic properties in various tumors. Here we report a greater sensitivity to HNE in PC3 and LNCaP cells compared to DU145 cells. In contrast to PC3 and LNCaP cells, HNE-treated DU145 cells showed a smaller reduction in growth and did not undergo apoptosis. In DU145 cells, HNE did not induce ROS production and DNA damage and generated a lower amount of HNE-protein adducts. DU145 cells had a greater GSH and GST A4 content and GSH/GST-mediated HNE detoxification. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a regulator of the antioxidant response. Nrf2 protein content and nuclear accumulation were higher in DU145 cells compared to PC3 and LNCaP cells, whereas the expression of KEAP1, the main negative regulator of Nrf2 activity, was lower. Inhibition of Nrf2 expression with specific siRNA resulted in a reduction in GST A4 expression and GS-HNE formation, indicating that Nrf2 controls HNE metabolism. In addition, Nrf2 knockdown sensitized DU145 cells to HNE-mediated antiproliferative and proapoptotic activity. In conclusion, we demonstrated that increased Nrf2 activity resulted in a reduction in HNE sensitivity in prostate cancer cells, suggesting a potential mechanism of resistance to pro-oxidant therapy.

Clinical manifestations, co-sensitizations, and immunoblotting profiles of buckwheat-allergic patients

BACKGROUND

  Buckwheat allergy is a rare food allergy in Europe and North America, whereas it is often described and studied in Asia. The aim of this study was to describe a series of patients with proven buckwheat allergy evaluated in an Italian allergy clinic. Co-sensitization to other food and inhalant allergens and immunoblotting profiles of buckwheat-allergic patients were studied.

METHODS

  Patients with suspected buckwheat allergy who attended the allergy clinic between January 1, 2006, and September 30, 2008, were evaluated. All patients underwent skin prick tests for a standard panel of inhalant and food allergens, prick-by-prick with buckwheat flour, buckwheat-specific IgE determinations, and double-blind placebo-controlled food challenge (DBPCFC) with buckwheat flour. Immunoblotting with buckwheat flour extract was performed on sera from buckwheat-allergic patients.

RESULTS

  Among 72 patients with suspected buckwheat allergy, 30 (41.7%) were sensitized to buckwheat and 24 had a positive DBPCFC. The mean buckwheat IgE level was 6.23 kUA/l (range, 0.16 to >100 kUA/l). Several IgE-binding proteins were identified and grouped into three patterns: a 16-kDa band in patients with predominantly gastrointestinal symptoms with grass and wheat flour co-sensitization, a 25-kDa band in patients with predominantly cutaneous symptoms and a low frequency of co-sensitization, and a 40-kDa band in patients with anaphylaxis and a low frequency of co-sensitization.

CONCLUSIONS

  Buckwheat allergy is an emerging food allergy in Italy. We identified three distinct patterns of clinical and laboratory characteristics, suggesting that specific allergens could be more frequently associated with clinical manifestations of different severity.

Induction of cell cycle arrest and DNA damage by the HDAC inhibitor panobinostat (LBH589) and the lipid peroxidation end product 4-hydroxynonenal in prostate cancer cells

Histone deacetylase inhibitors (HDACIs) are promising antineoplastic agents for the treatment of cancer. Here we report that the lipid peroxidation end product 4-hydroxynonenal (HNE) significantly potentiates the anti-tumor effects of the HDAC inhibitor panobinostat (LBH589) in the PC3 prostate cancer cell model. Panobinostat and HNE inhibited proliferation of PC3 cells and the combination of the two agents resulted in a significant combined effect. Cell cycle analysis revealed that both single agents and, to a greater extent, their combined treatment induced G2/M arrest, but cell death occurred in the combined treatment only. Furthermore, HNE and, to a greater extent, the combined treatment induced dephosphorylation of Cdc2 leading to progression into mitosis as confirmed by α-tubulin/DAPI staining and phospho-histone H3 (Ser10) analysis. To evaluate possible induction of DNA damage we utilized the marker phosphorylated histone H2A.X. Results showed that the combination of panobinostat and HNE induced significant DNA damage concomitant with the mitotic arrest. Then, by using androgen receptor (AR)-expressing PC3 cells we observed that the responsiveness to HNE and panobinostat was independent of the expression of functional AR. Taken together, our data suggest that HNE potentiates the antitumoral effect of the HDACI panobinostat in prostate cancer cells.

PPARgamma ligands inhibit telomerase activity and hTERT expression through modulation of the Myc/Mad/Max network in colon cancer cells

In human cells the length of telomeres depends on telomerase activity. This activity and the expression of the catalytic subunit of human telomerase reverse transcriptase (hTERT) is strongly up-regulated in most human cancers. hTERT expression is regulated by different transcription factors, such as c-Myc, Mad1 and Sp1. In this study, we demonstrated that 15d-PG J2 and rosiglitazone (an endogenous and synthetic peroxisome proliferators activated receptor γ (PPARγ) ligand, respectively) inhibited hTERT expression and telomerase activity in CaCo-2 colon cancer cells. Moreover, both ligands inhibited c-Myc protein expression and its E-box DNA binding activity. Additionally, Mad1 protein expression and its E-box DNA binding activity were strongly increased by 15d-PG J2 and, to a lesser extent, by rosiglitazone. Sp1 transcription factor expression and its GC-box DNA binding activity were not affected by both PPARγ ligands. Results obtained by transient transfection of CaCo-2 cells with pmaxFP-Green-PRL plasmid constructs containing the functional hTERT core promoter (including one E-box and five GC-boxes) and its E-box deleted sequences, cloned upstream of the green fluorescent protein reporter gene, demonstrated that 15d-PG J2, and with minor effectiveness, rosiglitazone, strongly reduced hTERT core promoter activity. E-boxes for Myc/Mad/Max binding showed a higher activity than GC-boxes for Sp1. By using GW9662, an antagonist of PPARγ, we demonstrated that the effects of 15d-PG J2 are completely PPARγ independent, whereas the effects of rosiglitazone on hTERT expression seem to be partially PPARγ independent. The regulation of hTERT expression by 15d-PG J2 and rosiglitazone, through the modulation of the Myc/Max/Mad1 network, may represent a new mechanism of action of these substances in inhibiting cell proliferation.

Increase of telomerase activity and hTERT expression in myelodysplastic syndromes

Telomerase enzyme, containing a catalytic subunit, the human telomerase reverse transcriptase (hTERT), and a small integral RNA component, synthesises the telomeres, the ends of eukaryotic chromosomes. Inhibition of telomerase activity leads the cells to senescence and death. Myelodysplastic syndromes (MSD) are hematological malignancies characterized by peripheral blood cytopenia and ineffective hematopoiesis. Telomerase activity and hTERT expression in MDS patients were independently investigated by different groups obtaining contradictory results. We analyzed telomerase activity and hTERT expression in the bone marrow of ten control, 15 MDS patients and two patients with AML, likely evolved from a previous MDS. Moreover, the expression of c-myc, mad1, p53 (transcription factors involved in hTERT expression regulation), has been investigated. Telomerase activity and hTERT expression increased in the MDS patients with respect to the controls. The analysis of the MDS subgroups, indicated that patients with more severe disease demonstrated significantly higher levels of hTERT expression and telomerase activity with respect to the patients with more favorable disease. c-Myc and p53 expressions were not significantly different between controls and MDS patients, whereas mad1 expression was increased in MDS patiens, particularly in those with more favorable disease. We hypothesize that mad1 increase can contribute to reduce the hTERT expression in the early stage of disease and we suggest that hTERT expression and telomerase activity, whether confirmed in larger series of cases could support other parameters in the diagnosis and stadiation of MDS.

Down-regulation of Notch1 expression is involved in HL-60 cell growth inhibition induced by 4-hydroxynonenal, a product of lipid peroxidation

The role of the Notch1 pathway has been well assessed in leukemia. Notch1 mutations are the most common ones in T acute lymphoblastic leukaemia patients which carry either oncogenic Notch1 forms or ineffective ubiquitin ligase implicated in Notch1 turnover. Abnormalities in the Notch1-Jagged1 system have been reported also in acute myelogenous leukaemia (AML) patients where Jagged1 is frequently over-expressed. Moreover, activating Notch1 mutations, as well, can occur in human AML and in leukemia cases with lineage infidelity. As a result, Notch1 signalling inhibition is an attractive goal in leukaemia therapy. Blockage/delay in cell differentiation and/or increase of proliferation are the main results of Notch1 signalling activation in several leukemic cell lines. Moreover, specific genes involved in cell growth control have been identified as Notch1 transcriptional targets, i.e. Cyclin D1 and c-Myc. 4-Hydroxynonenal (HNE), an aldehyde produced during lipid peroxidation, is involved in several pathological and physiological conditions, including inflammation; atherosclerosis; and neurodegenerative and chronic liver diseases. Moreover HNE has an antiproliferative/ differentiative effect in several cell lines, by affecting the expression of key genes, such as oncogenes (e.g. c-Myc, c-Myb), cyclins and telomerase. This prompted us to study the effect of HNE on Notch1 expression and its related signalling in HL-60 cells, a leukemic cell line widely used for differentiation studies. RT-PCR as well as Western blot assay showed Notch1down-regulation in HNE-treated HL-60 cells. The expression of Hes1, a Notch1 target gene, was concomitantly down-regulated by HNE treatment, reflecting Notch1 signalling inhibition. DAPT, an inhibitor of Notch activity, when added contemporary to HNE, further increased cell growth inhibition, without affecting apoptosis. Moreover, DAPT treatment reversed the HNE-induced differentiation. Overall these results suggest that Notch1 is a target for HNE and its down regulation is a key event in HNE-mediated inhibition of cell proliferation in the HL-60 cell line. By contrast our data do not support a role for Notch1 in HNE- induced differentiation or apoptosis.