Molecular engineering of a spheroid-penetrating phage nanovector for photodynamic treatment of colon cancer cells.

Photodynamic therapy (PDT) represents an emerging strategy to treat various malignancies, including colorectal cancer (CC), the third most common cancer type. This work presents an engineered M13 phage retargeted towards CC cells through pentavalent display of a disulfide-constrained peptide nonamer. The M13CC nanovector was conjugated with the photosensitizer Rose Bengal (RB), and the photodynamic anticancer effects of the resulting M13CC-RB bioconjugate were investigated on CC cells. We show that upon irradiation M13CC-RB is able to impair CC cell viability, and that this effect depends on i) photosensitizer concentration and ii) targeting efficiency towards CC cell lines, proving the specificity of the vector compared to unmodified M13 phage. We also demonstrate that M13CC-RB enhances generation and intracellular accumulation of reactive oxygen species (ROS) triggering CC cell death. To further investigate the anticancer potential of M13CC-RB, we performed PDT experiments on 3D CC spheroids, proving, for the first time, the ability of engineered M13 phage conjugates to deeply penetrate multicellular spheroids. Moreover, significant photodynamic effects, including spheroid disruption and cytotoxicity, were readily triggered at picomolar concentrations of the phage vector. Taken together, our results promote engineered M13 phages as promising nanovector platform for targeted photosensitization, paving the way to novel adjuvant approaches to fight CC malignancies.

Anticancer potential of allicin: A review.

Phytochemicals have attracted attention in the oncological field because they are biologically friendly and have relevant pharmacological activities. Thanks to the intense and unique spicy aroma, garlic is one of the most used plants for cooking. Its consumption is correlated to health beneficial effects towards several chronic diseases, such as cancer, mainly attributable to allicin, a bioactive sulfur compound stored in different plant parts in a precursor form. The objective of this review is to present and critically discuss the chemistry and biosynthesis of allicin, its pharmacokinetic profile, its anticancer mechanisms and molecular targets, and its selectivity towards tumor cells. The research carried out so far revealed that allicin suppresses the growth of different types of tumors. In particular, it targets many signaling pathways associated with cancer development. Future research directions are also outlined to further characterize this promising natural product.

Marine Anthraquinones: Pharmacological and Toxicological Issues.

The marine ecosystem, populated by a myriad of animals, plants, and microorganisms, is an inexhaustible reservoir of pharmacologically active molecules. Among the multiple secondary metabolites produced by marine sources, there are anthraquinones and their derivatives. Besides being mainly known to be produced by terrestrial species, even marine organisms and the uncountable kingdom of marine microorganisms biosynthesize anthraquinones. Anthraquinones possess many different biological activities, including a remarkable antitumor activity. However, due to their peculiar chemical structures, anthraquinones are often associated with toxicological issues, even relevant, such as genotoxicity and mutagenicity. The aim of this review is to critically describe the anticancer potential of anthraquinones derived from marine sources and their genotoxic and mutagenic potential. Marine-derived anthraquinones show a promising anticancer potential, although clinical studies are missing. Additionally, an in-depth investigation of their toxicological profile is needed before advocating anthraquinones as a therapeutic armamentarium in the oncological area.

Synthesis and Biological Evaluation of New Bis-Indolinone Derivatives Endowed with Cytotoxic Activity.

A series of new Knoevenagel adducts, bearing two indolinone systems, has been synthesized and evaluated on 60 human cancer cell lines according to protocols available at the National Cancer Institute (Bethesda, MD, USA). Some derivatives proved to be potent antiproliferative agents, showing GI50 values in the submicromolar range. Compound 5b emerged as the most active and was further studied in Jurkat cells in order to determine the effects on cell-cycle phases and the kind of cell death induced. Finally, oxidative stress and DNA damage induced by compound 5b were also analyzed.

On a Beam of Light: Photoprotective Activities of the Marine Carotenoids Astaxanthin and Fucoxanthin in Suppression of Inflammation and Cancer.

Every day, we come into contact with ultraviolet radiation (UVR). If under medical supervision, small amounts of UVR could be beneficial, the detrimental and hazardous effects of UVR exposure dictate an unbalance towards the risks on the risk-benefit ratio. Acute and chronic effects of ultraviolet-A and ultraviolet-B involve mainly the skin, the immune system, and the eyes. Photodamage is an umbrella term that includes general phototoxicity, photoaging, and cancer caused by UVR. All these phenomena are mediated by direct or indirect oxidative stress and inflammation and are strictly connected one to the other. Astaxanthin (ASX) and fucoxanthin (FX) are peculiar marine carotenoids characterized by outstanding antioxidant properties. In particular, ASX showed exceptional efficacy in counteracting all categories of photodamages, in vitro and in vivo, thanks to both antioxidant potential and activation of alternative pathways. Less evidence has been produced about FX, but it still represents an interesting promise to prevent the detrimental effect of UVR. Altogether, these results highlight the importance of digging into the marine ecosystem to look for new compounds that could be beneficial for human health and confirm that the marine environment is as much as full of active compounds as the terrestrial one, it just needs to be more explored.

Curcumin-1,2,3-Triazole Conjugation for Targeting the Cancer Apoptosis Machinery.

The burden of neoplastic diseases is widely recognized as a severe cause of mortality. The clinical inadequacy of most anticancer therapeutics urgently prompted intense drug discovery efforts toward the identification of new chemical entities endowed with a potent and safe antitumor profile. In this scenario, targeting cancer cells apoptosis machinery has emerged as a relevant strategy, useful for tackling the emergence of drug resistance. On this basis, a small library of naturally inspired hybrid molecules was obtained by combining, through a click chemistry approach, "privileged" synthons such as curcumin scaffold and 1,2,3-triazole building block. Compound 1, bearing a para-fluoro phenyl moiety, showed low-micromolar potency against T acute lymphoblastic leukemia cell growth. More in-depth biologic studies demonstrated, for this analog, cell death-inducing properties associated with its capability to simultaneously activate both the receptor and the mitochondrial apoptosis cascades. This peculiar behavior offers promises for achieving an expanded anticancer effect, namely intense cytotoxic response coupled with reduced predisposition of chemoresistance insurgence. Altogether, this study allowed the identification of compound 1 as a lead compound worth to be progressed as an anticancer drug candidate.

Benzophenones as xanthone-open model CYP11B1 inhibitors potentially useful for promoting wound healing.

The inhibition of steroidogenic cytochrome P450 enzymes has been shown to play a central role in the management of life-threatening diseases such as cancer, and indeed potent inhibitors of CYP19 (aromatase) and CYP17 (17α hydroxylase/17,20 lyase) are currently used for the treatment of breast, ovarian and prostate cancer. In the last few decades CYP11B1 (11-ß-hydroxylase) and CYP11B2 (aldosterone synthase), key enzymes in the biosynthesis of cortisol and aldosterone, respectively, have been also investigated as targets for the identification of new potent and selective agents for the treatment of Cushing's syndrome, impaired wound healing and cardiovascular diseases. In an effort to improve activity and synthetic feasibility of our different series of xanthone-based CYP11B1 and CYP11B2 inhibitors, a small series of imidazolylmethylbenzophenone-based compounds, previously reported as CYP19 inhibitors, was also tested on these new targets, in order to explore the role of a more flexible scaffold for the inhibition of CYP11B1 and -B2 isoforms. Compound 3 proved to be very potent and selective towards CYP11B1, and was thus selected for further optimization via appropriate decoration of the scaffold, leading to new potent 4'-substituted derivatives. In this second series, 4 and 8, carrying a methoxy group and a phenyl ring, respectively, proved to be low-nanomolar inhibitors of CYP11B1, despite a slight decrease in selectivity against CYP11B2. Moreover, unlike the benzophenones of the first series, the 4'-substituted derivatives also proved to be selective for CYP11B enzymes, showing very weak inhibition of CYP19 and CYP17. Notably, the promising result of a preliminary scratch test performed on compound 8 confirmed the potential of this compound as a wound-healing promoter.

Identification of a new tamoxifen-xanthene hybrid as pro-apoptotic anticancer agent.

Breast cancer is the most diagnosed type of cancer among women for which an exhaustive cure has not been discovered yet. Nowadays, tamoxifen still represents the gold standard for breast cancer therapy; it acts on both estrogen receptor-positive and estrogen receptor-negative breast cancers. Unfortunately, its toxicity and the related chemoresistance undermine its antitumor potential. In this paper, new tamoxifen-based derivatives with a rigid structural motif in their structure were designed, synthesized, and evaluated to assess their antitumor behavior. All the tested compounds affected estrogen receptor-positive tumor (MCF-7) cell growth, even with different extents, among which, the most active ones proved also to induce mitochondria-mediated apoptosis through activation of PARP cleavage, decrease in Bax/Bcl-2 ratio and increase in Bim gene expression levels. Here we found that the compound 1, carrying a rigid xanthene core, turned out to be the most promising of the set showing an activity profile comparable to that of tamoxifen. Furthermore, a more favorable genotoxic profile than tamoxifen made compound 1 a promising candidate for further studies.

Antitumor Potential of Marine and Freshwater Lectins.

Often, even the most effective antineoplastic drugs currently used in clinic do not efficiently allow complete healing due to the related toxicity. The reason for the toxicity lies in the lack of selectivity for cancer cells of the vast majority of anticancer agents. Thus, the need for new potent anticancer compounds characterized by a better toxicological profile is compelling. Lectins belong to a particular class of non-immunogenic glycoproteins and have the characteristics to selectively bind specific sugar sequences on the surface of cells. This property is exploited to exclusively bind cancer cells and exert antitumor activity through the induction of different forms of regulated cell death and the inhibition of cancer cell proliferation. Thanks to the extraordinary biodiversity, marine environments represent a unique source of active natural compounds with anticancer potential. Several marine and freshwater organisms, ranging from the simplest alga to the most complex vertebrate, are amazingly enriched in these proteins. Remarkably, all studies gathered in this review show the impressive anticancer effect of each studied marine lectin combined with irrelevant toxicity in vitro and in vivo and pave the way to design clinical trials to assess the real antineoplastic potential of these promising proteins. It provides a concise and precise description of the experimental results, their interpretation as well as the experimental conclusions that can be drawn.

Novel polyamine-based Histone deacetylases-Lysine demethylase 1 dual binding inhibitors.

Epigenetic modulators Histone deacetylases (HDACs) and Lysine demethylase (LSD1) are validated targets for anticancer therapy. Both HDAC1/2 and LSD1 are found in association with the repressor protein CoREST in a transcriptional co-repressor complex, which is responsible for gene silencing. Combined modulation of both targets results in a synergistic antiproliferative activity. In the present investigation, we report about the design and synthesis of a series of polyamine-based HDACs-LSD1 dual binding inhibitors obtained by coupling Vorinostat and Tranylcypromine. Compound 4 emerged as the most promising of the synthesized series, showing good inhibitory activity towards HDAC1 and LSD1 either in vitro and in cell-based assay (Ki = 42.52 ±â€¯8.94 nM and IC50 = 3.85 µM, respectively). Furthermore, at 70.0 µM compound 4 induced a more pronounced cytotoxic effect than Vorinostat (68.6% vs 56.6% of dead cells) in MCF7 cancer cell line.

Marine Sponge Natural Products with Anticancer Potential: An Updated Review.

Despite the huge investment into research and the significant effort and advances made in the search for new anticancer drugs in recent decades, cancer cure and treatment continue to be a formidable challenge. Many sources, including plants, animals, and minerals, have been explored in the oncological field because of the possibility of identifying novel molecular therapeutics. Marine sponges are a prolific source of secondary metabolites, a number of which showed intriguing tumor chemopreventive and chemotherapeutic properties. Recently, Food and Drug Administration-approved drugs derived from marine sponges have been shown to reduce metastatic breast cancer, malignant lymphoma, and Hodgkin's disease. The chemopreventive and potential anticancer activity of marine sponge-derived compounds could be explained by multiple cellular and molecular mechanisms, including DNA protection, cell-cycle modulation, apoptosis, and anti-inflammatory activities as well as their ability to chemosensitize cancer cells to traditional antiblastic chemotherapy. The present article aims to depict the multiple mechanisms involved in the chemopreventive and therapeutic effects of marine sponges and critically explore the limitations and challenges associated with the development of marine sponge-based anticancer strategy.

Perspectives in Designing Multifunctional Molecules in Antipsychotic Drug Discovery.

Preclinical Research A novel and promising approach to overcome the limits of single-target therapy is represented by the multitarget approach. This strategy aims to simultaneously modulate several targets involved in the pathophysiology of a multifactorial disease, with the potential to enhance therapeutic effectiveness and improve drug safety. Although there has been a marked growth in the design of multitarget drugs (MTDs) in the last years in the context of anti-Alzheimer and anti-cancer drug discovery, a parallel expansion was not observed in antipsychotic drugs, even that for psychiatric disorders there is a cogent medical need for new treatments. The discovery of new MTDs is a challenging task and we will describe the main strategies that have been developed over the years for the design of multifunctional molecules in antipsychotic drug discovery. In particular, we will focus on the few available MTDs based on the design of selective serotonin re-uptake inhibitors, used as antidepressants and in the treatment of schizophrenia. Drug Dev Res 77 : 437-443, 2016. © 2016 Wiley Periodicals, Inc.

Immunogenicity of ferroptosis in cancer: a matter of context?

Ferroptosis is a variant of regulated cell death (RCD) elicited by an imbalance of cellular redox homeostasis that culminates with extensive lipid peroxidation and rapid plasma membrane breakdown. Since other necrotic forms of RCD, such as necroptosis, are highly immunogenic, ferroptosis inducers have attracted considerable attention as potential tools to selectively kill malignant cells while eliciting therapeutically relevant tumor-targeting immune responses. However, rather than being consistently immunogenic, ferroptosis mediates context-dependent effects on anticancer immunity. The inability of ferroptotic cancer cells to elicit adaptive immune responses may arise from contextual deficiencies in intrinsic aspects of the process, such as adjuvanticity and antigenicity, or from microenvironmental defects imposed by ferroptotic cancer cells themselves or elicited by the induction of ferroptosis in immune cells.

CX3CL1 release during immunogenic apoptosis is associated with enhanced anti-tumour immunity.

Introduction: Immunogenic cell death (ICD) has emerged as a novel option for cancer immunotherapy. The key determinants of ICD encompass antigenicity (the presence of antigens) and adjuvanticity, which involves the release of damage-associated molecular patterns (DAMPs) and various cytokines and chemokines. CX3CL1, also known as neurotactin or fractalkine, is a chemokine involved in cellular signalling and immune cell interactions. CX3CL1 has been denoted as a "find me" signal that stimulates chemotaxis of immune cells towards dying cells, facilitating efferocytosis and antigen presentation. However, in the context of ICD, it is uncertain whether CX3CL1 is an important mediator of the effects of ICD. Methods: In this study, we investigated the intricate role of CX3CL1 in immunogenic apoptosis induced by mitoxantrone (MTX) in cancer cells. The Luminex xMAP technology was used to quantify murine cytokines, chemokines and growth factors to identify pivotal regulatory cytokines released by murine fibrosarcoma MCA205 and melanoma B16-F10 cells undergoing ICD. Moreover, a murine tumour prophylactic vaccination model was employed to analyse the effect of CX3CL1 on the activation of an adaptive immune response against MCA205 cells undergoing ICD. Furthermore, thorough analysis of the TCGA-SKCM public dataset from 98 melanoma patients revealed the role of CX3CL1 and its receptor CX3CR1 in melanoma patients. Results: Our findings demonstrate enhanced CX3CL1 release from apoptotic MCA205 and B16-F10 cells (regardless of the cell type) but not if they are undergoing ferroptosis or accidental necrosis. Moreover, the addition of recombinant CX3CL1 to non-immunogenic doses of MTX-treated, apoptotically dying cancer cells in the murine prophylactic tumour vaccination model induced a robust immunogenic response, effectively increasing the survival of the mice. Furthermore, analysis of melanoma patient data revealed enhanced survival rates in individuals exhibiting elevated levels of CD8+ T cells expressing CX3CR1. Conclusion: These data collectively underscore the importance of the release of CX3CL1 in eliciting an immunogenic response against dying cancer cells and suggest that CX3CL1 may serve as a key switch in conferring immunogenicity to apoptosis.

Ferroptosis: friend or foe in cancer immunotherapy?

Ferroptosis has gained interest due to it immunogenicity and the higher sensitivity of cancer cells to it. However, it was recently shown that ferroptosis in tumor-associated neutrophils leads to immunosuppression and negatively impacts therapy. Here, we discuss the potential implications of the two sides (friend versus foe) of ferroptosis in cancer immunotherapy.

Immunogenic Cell Death and Role of Nanomaterials Serving as Therapeutic Vaccine for Personalized Cancer Immunotherapy.

Immunogenic cell death (ICD) is a rapidly growing research area representing one of the emerging therapeutic strategies of cancer immunotherapy. ICD is an umbrella term covering several cell death modalities including apoptosis, necroptosis, ferroptosis and pyroptosis, and is the product of a balanced combination of adjuvanticity (damage-associated molecular patterns and chemokines/cytokines) and antigenicity (tumor associated antigens). Only a limited number of anti-cancer therapies are available to induce ICD in experimental cancer therapies and even much less is available for clinical use. To overcome this limitation, nanomaterials can be used to increase the immunogenicity of cancer cells killed by anti-cancer therapy, which in themselves are not necessarily immunogenic. In this review, we outline the current state of knowledge of ICD modalities and discuss achievements in using nanomaterials to increase the immunogenicity of dying cancer cells. The emerging trends in modulating the immunogenicity of dying cancer cells in experimental and translational cancer therapies and the challenges facing them are described. In conclusion, nanomaterials are expected to drive further progress in their use to increase efficacy of anti-cancer therapy based on ICD induction and in the future, it is necessary to validate these strategies in clinical settings, which will be a challenging research area.

In Vitro Veritas: From 2D Cultures to Organ-on-a-Chip Models to Study Immunogenic Cell Death in the Tumor Microenvironment.

Immunogenic cell death (ICD) is a functionally unique form of cell death that promotes a T-cell-dependent anti-tumor immune response specific to antigens originating from dying cancer cells. Many anticancer agents and strategies induce ICD, but despite their robust effects in vitro and in vivo on mice, translation into the clinic remains challenging. A major hindrance in antitumor research is the poor predictive ability of classic 2D in vitro models, which do not consider tumor biological complexity, such as the contribution of the tumor microenvironment (TME), which plays a crucial role in immunosuppression and cancer evasion. In this review, we describe different tumor models, from 2D cultures to organ-on-a-chip technology, as well as spheroids and perfusion bioreactors, all of which mimic the different degrees of the TME complexity. Next, we discuss how 3D cell cultures can be applied to study ICD and how to increase the translational potential of the ICD inducers. Finally, novel research directions are provided regarding ICD in the 3D cellular context which may lead to novel immunotherapies for cancer.

Synthesis, in vitro cytotoxicity, molecular docking and ADME study of some indolin-2-one linked 1,2,3-triazole derivatives.

In pursuit of an anticancer lead, a library of 1,2,3-triazole derivatives (7a-x) was prepared, characterized and screened for in vitro cytotoxicity in different cell lines. Most of the compounds proved to be cytotoxic with IC50 values in the low micromolar range. Further studies showed that the most active compound 7c induces caspase-dependent apoptosis in Jurkat cells by activating both the intrinsic and the extrinsic apoptotic pathways and perturbs cell-cycle progression. Moreover, 7c did not show any genotoxic activity. Molecular docking simulations were performed against epidermal growth factor receptor (EGFR). Docking experiments showed that, compounds 7c, 7o and 7 v bind within active sites of epidermal growth factor receptor EGFR (Pdb ID: 6P8Q) by strong hydrogen bonds with residue MET793, Pi-Sulfur with residue MET790 and Pi-Alkyl type interactions with residues LEU788, ALA743. The SwissADME webserver investigation suggested that most of the synthesized compounds follow the rules of drug-likeness.

Perillaldehyde is a new ferroptosis inducer with a relevant clinical potential for acute myeloid leukemia therapy.

Ferroptosis induction is an emerging strategy to treat cancer and contrast the tricky issue of chemoresistance, which can arise towards apoptosis. This work elucidates the anticancer mechanisms evoked by perillaldehyde, a monoterpenoid isolated from Ammodaucus leucotrichus Coss. & Dur. We investigated and characterized its antileukemic potential in vitro, disclosing its ability to trigger ferroptosis. Specifically, perillaldehyde induced lipid peroxidation, decreased glutathione peroxidase 4 protein expression, and depleted intracellular glutathione on HL-60 promyelocytic leukemia cells. Besides, it stimulated the active secretion of ATP, one of the most crucial events in the induction of efficient anticancer response, prompting further studies to disclose its possible nature as an immunogenic cell death inducer. To preliminarily assess the clinical relevance of perillaldehyde, we tested its ability to induce cell death on patient-derived acute myeloid leukemia biopsies, recording a similar mechanism of action and potency compared to HL-60 cells. To round the study off, we tested its selectivity towards tumor cells and disclosed lower toxicity on normal cells compared to both HL-60 and acute myeloid leukemia biopsies. Altogether, these data depict a favorable risk-benefit profile for perillaldehyde and reveal its peculiar antileukemic potential, which qualifies this natural product to proceed further through the drug development pipeline.

In Vitro Investigation of the Anticancer Properties of Ammodaucus Leucotrichus Coss. & Dur.

Little is known about the pharmacological activity of Ammodaucus leucotrichus Coss. & Dur., a small annual species that grows in the Saharan and sub-Saharan countries. In the present study, we investigated whether the standardized ethanolic extract of A. leucotrichus fruits and R-perillaldehyde, a monoterpenoid isolated from A. leucotrichus fruits, are able to affect different processes involved in different phases of cancer development. In particular, we explored their genoprotective, proapoptotic, antiproliferative, and cytodifferentiating potential on different human cell models. We analyzed the genoprotective and proapoptotic activity on human lymphoblast cells (TK6) using the micronucleus test, and the cytodifferentiation effects on human promyelocytic cells (HL60) through the evaluation of different markers of differentiation forward granulocytes or monocytes. The results showed that the extract and perillaldehyde were able to induce apoptosis and protect from clastogen-induced DNA damage. To our best knowledge, this is the first report on the ability of A. leucotrichus and perillaldehyde to induce apoptosis and protect DNA from the toxicity of different compounds. Data reported in this work are the starting point for their pharmacological use. Going forward, efforts to determine their effects on other events associated with cancer development, such as angiogenesis and metastasization, will provide important information and improve our understanding of their potential in cancer therapy.