Combination of albendazole and 2-methoxyestradiol significantly improves the survival of HCT-116 tumor-bearing nude mice

Application of Box-Behnken design in the optimization and development of albendazole-loaded zein nanoparticles as a drug repurposing approach for colorectal cancer management

Colorectal cancer (CRC) is the second cancer worldwide representing a major global health challenge. Numerous effective anticancer drugs have been developed in the last decade, yet the problem remains due to their low therapeutic index and nonspecificity. A new anticancer therapeutic paradigm is based on repurposing and nanoformulating drugs. Albendazole (ALB), a popular anthelmintic agent, was recently repurposed against CRC cells. In this study zein, an amphiphilic protein, was used to formulate nanoparticles (NPs) loaded with ALB. Box-Behnken design was selected to optimize the loaded NPs, the concentrations of polyvinyl alcohol, acetic acid, and the weight of zein were the independent variables. The dependent variables were the particle size, polydispersity index, and zeta potential. The optimized formula displayed a size of 84.3 ± 0.41 nm, PDI 0.13 ± 0.012, and a zeta potential of 42.5 ± 2.35 mV. ALB was successfully encapsulated into zein NPs and the release study revealed a desirable pH-responsive drug release behavior, that was negligible release during the first 2 h at pH 1.2 and progressive in the simulated colon environment reaching 71.1 ± 0.34 % at 6 h and 92.4 ± 1.11 % at 24 h. The anticancer effect of the loaded NPs on the human HCT116 cells showed favorable effects at 1 μM concentration with a significant decrease in the IC50 at days 2 and 3 upon loading albendazole into zein NPs. Zein nanoparticles proved to be prospective nanocarriers that could be used for the delivery of repurposed drugs in CRC treatment.

Enhancing antitumor efficacy of oncolytic virus M1 via albendazole-sustained CD8+ T cell activation

The immune response plays a crucial role in the functionality of oncolytic viruses. In this study, Albendazole, an antihelminthic drug known to modulate the immune checkpoint PD-L1, was combined with the oncolytic virus M1 (OVM1) to treat mice with either prostate cancer (RM-1) or glioma (GL261) tumors. This combination therapy enhanced anti-tumor effects in immunocompetent mice, but not in immunodeficient ones, without increasing OVM1 replication. Instead, it led to an increase in the number of CD8+ T cells within the tumor, downregulated the expression of PD1 on CD8+ T cells, and upregulated activation markers such as Ki67, CD44, and CD69 and the secretion of cytotoxic factors including interferon (IFN)-γ, granzyme B, and tumor necrosis factor (TNF)-α. Consistently, it enhanced the in vitro tumor-killing activity of lymphocytes from tumor-draining lymph nodes or spleens. The synergistic effect of Albendazole on OVM1 was abolished by depleting CD8+ T cells, suggesting a CD8+ T cell-dependent mechanism. In addition, Albendazole and OVM1 therapy increased CTLA4 expression in the spleen, and the addition of CTLA4 antibodies further enhanced the anti-tumor efficacy in vivo. In summary, Albendazole can act synergistically with oncolytic viruses via CD8+ T cell activation, and the Albendazole/OVM1 combination can overcome resistance to CTLA4-based immune checkpoint blockade therapy.

Albendazole inhibits colon cancer progression and therapy resistance by targeting ubiquitin ligase RNF20

BACKGROUND

The repurposing of FDA-approved drugs for anti-cancer therapies is appealing due to their established safety profiles and pharmacokinetic properties and can be quickly moved into clinical trials. Cancer progression and resistance to conventional chemotherapy remain the key hurdles in improving the clinical management of colon cancer patients and associated mortality.

METHODS

High-throughput screening (HTS) was performed using an annotated library of 1,600 FDA-approved drugs to identify drugs with strong anti-CRC properties. The candidate drug exhibiting most promising inhibitory effects in in-vitro studies was tested for its efficacy using in-vivo models of CRC progression and chemoresistance and patient derived organoids (PTDOs).

RESULTS

Albendazole, an anti-helminth drug, demonstrated the strongest inhibitory effects on the tumorigenic potentials of CRC cells, xenograft tumor growth and organoids from mice. Also, albendazole sensitized the chemoresistant CRC cells to 5-fluorouracil (5-FU) and oxaliplatin suggesting potential to treat chemoresistant CRC. Mechanistically, Albendazole treatment modulated the expression of RNF20, to promote apoptosis in CRC cells by delaying the G2/M phase and suppressing anti-apoptotic-Bcl2 family transcription.

CONCLUSIONS

Albendazole, an FDA approved drug, carries strong therapeutic potential to treat colon cancers which are aggressive and potentially resistant to conventional chemotherapeutic agents. Our findings also lay the groundwork for further clinical testing.

The Use of Cyclodextrin Inclusion Complexes to Increase the Solubility and Pharmacokinetic Profile of Albendazole

Albendazole is the preferred deworming drug and has strong insecticidal effects on human and animal helminth parasites, showing remarkable activity against hepatocellular carcinoma and colorectal cancer cells. However, it is classified as being in class II in the Biopharmaceutics Classification System due to its poor water solubility (0.2 mg/L) and high permeability, which make the clinical application of albendazole impractical. Through complexation with methyl-β-cyclodextrin, as the best result so far, albendazole's water solubility was increased by 150,000 times, and albendazole could be 90% released during the first 10 min. In an in vivo pharmacokinetic study, the Cmax and Tmax of the active metabolized sulfoxide were changed from 2.81 µg/mL at 3 h to 10.2 µg/mL at 6 h and the AUC0-48 was increased from 50.72 h⁎μg/mL to 119.95 h⁎μg/mL, indicating that the inclusion complex obtained can be used as a new oral therapeutic anti-anthelmintic and anti-tumor agent formulation.

Melatonin in Combination with Albendazole or Albendazole Sulfoxide Produces a Synergistic Cytotoxicity against Malignant Glioma Cells through Autophagy and Apoptosis

Glioblastoma is the most aggressive and lethal brain tumor in adults, presenting diffuse brain infiltration, necrosis, and drug resistance. Although new drugs have been approved for recurrent patients, the median survival rate is two years; therefore, new alternatives to treat these patients are required. Previous studies have reported the anticancer activity of albendazole, its active metabolite albendazole sulfoxide, and melatonin; therefore, the present study was performed to evaluate if the combination of melatonin with albendazole or with albendazole sulfoxide induces an additive or synergistic cytotoxic effect on C6 and RG2 rat glioma cells, as well as on U87 human glioblastoma cells. Drug interaction was determined by the Chou-Talalay method. We evaluated the mechanism of cell death by flow cytometry, immunofluorescence, and crystal violet staining. The cytotoxicity of the combinations was mainly synergistic. The combined treatments induced significantly more apoptotic and autophagic cell death on the glioma cell lines. Additionally, albendazole and albendazole sulfoxide inhibited proliferation independently of melatonin. Our data justify continuing with the evaluation of this proposal since the combinations could be a potential strategy to aid in the treatment of glioblastoma.

The potential anti-cancer effects of quercetin on blood, prostate and lung cancers: An update

Cancer is caused by abnormal proliferation of cells and aberrant recognition of the immune system. According to recent studies, natural products are most likely to be effective at preventing cancer without causing any noticeable complications. Among the bioactive flavonoids found in fruits and vegetables, quercetin is known for its anti-inflammatory, antioxidant, and anticancer properties. This review aims to highlight the potential therapeutic effects of quercetin on some different types of cancers including blood, lung and prostate cancers.

Repurposing of Benzimidazole Anthelmintic Drugs as Cancer Therapeutics

Simple Summary

Although non-prescription anthelmintics are often used for cancer treatment, there is a lack of information regarding their anti-cancer effects in clinical settings. The aims of our review are to describe the possibilities and limitations of the anti-cancer effects of benzimidazole anthelmintics and to suggest ways to overcome these limitations. The results of the current review illustrate the potential development of anthelmintics as a useful strategy for cancer treatment based on much preclinical evidence. Furthermore, they suggest that more rigorous studies on whole anti-cancer pathways and development strategies, including formulations, could result in significantly enhanced anti-cancer effects of benzimidazoles as a repurposed cancer therapy in clinical settings.

Abstract

Benzimidazoles have shown significant promise for repurposing as a cancer therapy. The aims of this review are to investigate the possibilities and limitations of the anti-cancer effects of benzimidazole anthelmintics and to suggest ways to overcome these limitations. This review included studies on the anti-cancer effects of 11 benzimidazoles. Largely divided into three parts, i.e., preclinical anti-cancer effects, clinical anti-cancer effects, and pharmacokinetic properties, we examine the characteristics of each benzimidazole and attempt to elucidate its key properties. Although many studies have demonstrated the anti-cancer effects of benzimidazoles, there is limited evidence regarding their effects in clinical settings. This might be because the clinical trials conducted using benzimidazoles failed to restrict their participants with specific criteria including cancer entities, cancer stages, and genetic characteristics of the participants. In addition, these drugs have limitations including low bioavailability, which results in insufficient plasma concentration levels. Additional studies on whole anti-cancer pathways and development strategies, including formulations, could result significant enhancements of the anti-cancer effects of benzimidazoles in clinical situations.

In silico to In vivo development of a polyherbal against Haemonchus contortus

Haemonchus contortus is a major constraint in the development of small ruminant subsector due to significant production losses incurred by it. The present study explores the antiparasitic potential of three anthelmintic plants (Butea monosperma, Vitex negundo and Catharanthus roseus (L.) G.Don) against H. contortus taking albendazole as the standard. In silico molecular docking and pharmacokinetic prediction studies were conducted with known bioactive molecules of these plants (palasonin, vinblastine, vincristine, betulinic acid and ursolic acid) against Glutamate Dehydrogenase (GDH) and tubulin molecules of the parasite. Methanolic extracts of these herbs were fractionated (hexane, ethyl acetate, chloroform and methanol) and used in in vitro larvicidal studies. Based on the in vitro data, two herbal prototypes were developed and clinically tested. All the 5 ligand molecules showed better binding affnity for GDH and tubulin protein as compared with albendazole and shared similar binding site in the core of the GDH hexamer with slight variations. Albendazole approximately stacked against GLY190A residue, showing hydrophobic interactions with PRO157A and a Pi-cation electrostatic interaction with ARG390 along with four hydrogen bonds. Vincristine formed 2 pi-anionic electrostatic bonds with ASP158 of B and C subunits alongwith hydrogen bonding and hydrophobic interaction and an additional pi-anion electrostatic interaction at ASP158A for vinblastine. Albendazole bound to α-tubulin next to colchicine site whereas vinblastine is bound at the nearby laulimalide/peloruside site of the dimer. Betulinic acid showed lateral interaction between the H2-H3 loop of one alpha subunit and H10 of the adjacent alpha subunit of two tubulin dimers. Ursolic acid and palasonin bound at the intradimer N site of microtubulin involving the H1-H7 and H1-H2 zone, respectively. The in vitro studies demonstrated good dose dependent anthelmintic potential. Both the prototypes were quite efficacious in clearing the infection, keeping it to a minimal for more than 5 months, probably, through direct anthelmintic effect through GDH, tubulin depolymerization and uncoupling as well as indirectly through immunomodulation along with antioxidant and anti-inflammatory properties.

Combination of quercetin and 2-methoxyestradiol inhibits epithelial-mesenchymal transition in PC-3 cell line via Wnt signaling pathway

Aim:

We have previously reported that quercetin (Qu) regulates epithelial–mesenchymal transition (EMT) by modulating Wnt signaling components. In this study, we investigated the synergistic effect of Qu and 2-methoxyestradiol (2-ME) and the role of Wnt signaling components in regulating EMT in PC-3 cells.

Materials & methods:

EMT was induced by treating PC-3 cells with TGF-β, followed by evaluation of expression of EMT markers and Wnt signaling proteins in naive, induced and after exposing induced cells to Qu and 2-ME at both gene and protein level by real-time PCR (RT-PCR) and western blot, respectively.

Results:

Qu and 2-ME synergistically downregulated mesenchymal markers with simultaneous upregulation of epithelial markers. Wnt signaling proteins expression was also downregulated by Qu and 2-ME in TGF-β-induced EMT in PC-3 cells.

Conclusion:

Thus, combination therapy of Qu and 2-ME could be a new promising therapeutic approach for the treatment of prostate cancer.

The current study describes the synergistic effect of quercetin and 2-methoxyestradiol and the role of Wnt signaling components in regulating epithelial–mesenchymal transition (EMT) in PC-3 cells. EMT was induced by treating PC-3 cells with TGF-β, followed by the evaluation of expression of EMT markers and Wnt signaling proteins in naive and induced states. Quercetin and 2-methoxyestradiol could synergistically downregulate mesenchymal markers with simultaneous upregulation of epithelial markers along with the downregulation of Wnt signaling proteins.

1H-benzimidazole-2-yl hydrazones as tubulin-targeting agents: Synthesis, structural characterization, anthelmintic activity and antiproliferative activity against MCF-7 breast carcinoma cells and molecular docking studies

In the present study, fifteen benzimidazolyl-2-hydrazones 7a-7o of fluoro-, hydroxy- and methoxy-substituted benzaldehydes and 1,3-benzodioxole-5-carbaldehyde were synthesized and their structure was identified by IR, NMR, and elemental analysis. The compounds 7j 2-(3-hydroxybenzylidene)-1-(5(6)-methyl-1H-benzimidazol-2-yl)hydrazone and 7i 2-(3-hydroxybenzylidene)-1-(1H-benzimidazol-2-yl)hydrazone have exerted the strongest anthelmintic activity (100% after 24 h incubation period at 37 °C) against isolated muscle larvae of Trichinella spiralis in an in vitro experiment. The in vitro cytotoxicity assay towards MCF-7 breast cancer cells and mouse embryo fibroblasts 3T3 showed that the studied benzimidazolyl-2-hydrazones exhibit low to moderate cytotoxic effects. The ability of the studied benzimidazolyl-2-hydrazones to modulate microtubule polymerization was confirmed and suggested that their anthelmintic action is mediated through inhibition of the tubulin polymerization likewise the other known benzimidazole anthelmitics. It was also shown that the four most promising benzimidazolyl-2-hydrazones do not affect significantly the AChE activity even at high tested concentration, thus indicating that they do not have the potential for neurotoxic effects. The binding mode of compounds 7j and 7n in the colchicine-binding site of tubulin were clarified by molecular docking simulations. Taken together, these results demonstrate that for the synthesized benzimidazole derivatives the anthelmintic activity against T. spiralis and the inhibition of tubulin polymerization are closely related.

Albendazole and Mebendazole as Anti-Parasitic and Anti-Cancer Agents: an Update

The use of albendazole and mebendazole, i.e., benzimidazole broad-spectrum anthelmintics, in treatment of parasitic infections, as well as cancers, is briefly reviewed. These drugs are known to block the microtubule systems of parasites and mammalian cells leading to inhibition of glucose uptake and transport and finally cell death. Eventually they exhibit ovicidal, larvicidal, and vermicidal effects on parasites, and tumoricidal effects on hosts. Albendazole and mebendazole are most frequently prescribed for treatment of intestinal nematode infections (ascariasis, hookworm infections, trichuriasis, strongyloidiasis, and enterobiasis) and can also be used for intestinal tapeworm infections (taeniases and hymenolepiasis). However, these drugs also exhibit considerable therapeutic effects against tissue nematode/cestode infections (visceral, ocular, neural, and cutaneous larva migrans, anisakiasis, trichinosis, hepatic and intestinal capillariasis, angiostrongyliasis, gnathostomiasis, gongylonemiasis, thelaziasis, dracunculiasis, cerebral and subcutaneous cysticercosis, and echinococcosis). Albendazole is also used for treatment of filarial infections (lymphatic filariasis, onchocerciasis, loiasis, mansonellosis, and dirofilariasis) alone or in combination with other drugs, such as ivermectin or diethylcarbamazine. Albendazole was tried even for treatment of trematode (fascioliasis, clonorchiasis, opisthorchiasis, and intestinal fluke infections) and protozoan infections (giardiasis, vaginal trichomoniasis, cryptosporidiosis, and microsporidiosis). These drugs are generally safe with few side effects; however, when they are used for prolonged time (>14-28 days) or even only 1 time, liver toxicity and other side reactions may occur. In hookworms, Trichuris trichiura, possibly Ascaris lumbricoides, Wuchereria bancrofti, and Giardia sp., there are emerging issues of drug resistance. It is of particular note that albendazole and mebendazole have been repositioned as promising anti-cancer drugs. These drugs have been shown to be active in vitro and in vivo (animals) against liver, lung, ovary, prostate, colorectal, breast, head and neck cancers, and melanoma. Two clinical reports for albendazole and 2 case reports for mebendazole have revealed promising effects of these drugs in human patients having variable types of cancers. However, because of the toxicity of albendazole, for example, neutropenia due to myelosuppression, if high doses are used for a prolonged time, mebendazole is currently more popularly used than albendazole in anti-cancer clinical trials.

Albendazole exerts antiproliferative effects on prostate cancer cells by inducing reactive oxygen species generation

Benzimidazole derivatives are used for their antihelmintic properties, but have also been reported to exert anticancer effects. In the present study, the anticancer effects of albendazole on prostate cancer cells were assessed using proliferation, clonogenic and migration assays. To investigate the anticancer mechanisms of albendazole, reactive oxygen species (ROS) levels were measured, and the expression of genes associated with oxidative stress and Wnt/β-catenin signaling was confirmed by reverse transcription-quantitative PCR and western blotting. Albendazole selectively inhibited the proliferation of the PC3, DU145, LNCaP and AT2 prostate cancer cell lines at concentrations that did not affect the proliferation of a normal prostate cell line (RWPE-1). Albendazole also inhibited the colony formation and migration of PC3 and DU145 cells, as well as inducing ROS production. Diphenyleneiodonium chloride, an inhibitor of NADPH oxidase (NOX), one of the sources of ROS, decreased basal ROS levels in the PC3 and DU145 cells, but did not reduce albendazole-associated ROS production, suggesting that ROS production following albendazole treatment was NOX-independent. The anticancer effect was decreased when albendazole-induced ROS was reduced by treatment with antioxidants (glutathione and N-acetylcysteine). Furthermore, albendazole decreased the mRNA expression of CDGSH iron sulfur domain 2, which regulates antioxidant activity against ROS, as well as the antioxidant enzymes catalase, and glutathione peroxidase 1 and 3. Albendazole also decreased the mRNA expression of catenin β1 and transcription factor 4, which regulate Wnt/β-catenin signaling and its associated targets, Twist family BHLH transcription factor 1 and BCL2. The albendazole-related decrease in the expression levels of oxidative stress-related genes and Wnt/β-catenin signaling proteins was thought to be associated with ROS production. These results suggest that the antihelmintic drug, albendazole, has inhibitory effects against prostate cancer cells in vitro. Therefore, albendazole may potentially be used as a novel anticancer agent for prostate cancer.

Repositioning of Antiparasitic Drugs for Tumor Treatment

Drug repositioning is a strategy for identifying new antitumor drugs; this strategy allows existing and approved clinical drugs to be innovatively repurposed to treat tumors. Based on the similarities between parasitic diseases and cancer, recent studies aimed to investigate the efficacy of existing antiparasitic drugs in cancer. In this review, we selected two antihelminthic drugs (macrolides and benzimidazoles) and two antiprotozoal drugs (artemisinin and its derivatives, and quinolines) and summarized the research progresses made to date on the role of these drugs in cancer. Overall, these drugs regulate tumor growth via multiple targets, pathways, and modes of action. These antiparasitic drugs are good candidates for comprehensive, in-depth analyses of tumor occurrence and development. In-depth studies may improve the current tumor diagnoses and treatment regimens. However, for clinical application, current investigations are still insufficient, warranting more comprehensive analyses.

Solid Polymeric Nanoparticles of Albendazole: Synthesis, Physico-Chemical Characterization and Biological Activity

Albendazole is a benzimidazole derivative with documented antitumor activity and low toxicity to healthy cells. The major disadvantage in terms of clinical use is its low aqueous solubility which limits its bioavailability. Albendazole was incorporated into stable and homogeneous polyurethane structures with the aim of obtaining an improved drug delivery system model. Spectral and thermal analysis was used to investigate the encapsulation process and confirmed the presence of albendazole inside the nanoparticles. The in vitro anticancer properties of albendazole encapsulated in polyurethane structures versus the un-encapsulated compound were tested on two breast cancer cell lines, MCF-7 and MDA-MB-231, in terms of cellular viability and apoptosis induction. The study showed that the encapsulation process enhanced the antitumor activity of albendazole on the MCF-7 and MDA-MB-23 breast cancer lines. The cytotoxic activity manifested in a concentration-dependent manner and was accompanied by changes in cell morphology and nuclear fragmentation.

Rapid determination of nematode cell and organ susceptibility to toxic treatments

In research focused on the intestine of parasitic nematodes, we recently identified small molecule inhibitors toxic to intestinal cells of larval Ascaris suum (nematode intestinal toxins/toxicants; “NITs”). Some NITs had anthelmintic activity across the phylogenetic diversity of the Nematoda. The whole-worm motility inhibition assay quantified anthelmintic activity, but worm responses to NITs in relation to pathology or affected molecular pathways was not acquired. In this study we extended this research to more comprehensively determine in whole larval A. suum the cells, organ systems, molecular targets, and potential cellular pathways involved in mechanisms of toxicity leading to cell death. The experimental system utilized fluorescent nuclear probes (bisbenzimide, propidium iodide), NITs, an A. suum larval parasite culture system and transcriptional responses (RNA-seq) to NITs. The approach provides for rapid resolution of NIT-induced cell death among organ systems (e.g. intestine, excretory, esophagus, hypodermis and seam cells, and nervous), discriminates among NITs based on cell death profiles, and identifies cells and organ systems with the greatest NIT sensitivity (e.g. intestine and apparent neuronal cells adjacent to the nerve ring). Application was extended to identify cells and organs sensitive to several existing anthelmintics. This approach also resolved intestinal cell death and irreparable damage induced in adult A. suum by two NITs, establishing a new model to elucidate relevant pathologic mechanisms in adult worms. RNA-seq analysis resolved A. suum genes responsive to treatments with three NITs, identifying dihydroorotate dehydrogenase (uridine synthesis) and RAB GTPase(s) (vesicle transport) as potential targets/pathways leading to cell death. A set of genes induced by all three NITs tested suggest common stress or survival responses activated by NITs. Beyond the presented specific lines of research, elements of the overall experimental system presented in this study have broad application toward systematic development of new anthelmintics.

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A unique rapid cell death assay was developed for parasitic nematodes.

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Multiple drug-like molecules cause widespread cell death in many organs of A. suum.

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Multiple cell and organ systems were validated as targets for anthelmintics.

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Potential drug targets/pathways were implicated in activating cell death processes.

The Antitumor Potentials of Benzimidazole Anthelmintics as Repurposing Drugs

The development of refractory tumor cells limits therapeutic efficacy in cancer by activating mechanisms that promote cellular proliferation, migration, invasion, metastasis, and survival. Benzimidazole anthelmintics have broad-spectrum action to remove parasites both in human and veterinary medicine. In addition to being antiparasitic agents, benzimidazole anthelmintics are known to exert anticancer activities, such as the disruption of microtubule polymerization, the induction of apoptosis, cell cycle (G2/M) arrest, anti-angiogenesis, and blockage of glucose transport. These antitumorigenic effects even extend to cancer cells resistant to approved therapies and when in combination with conventional therapeutics, enhance anticancer efficacy and hold promise as adjuvants. Above all, these anthelmintics may offer a broad, safe spectrum to treat cancer, as demonstrated by their long history of use as antiparasitic agents. The present review summarizes central literature regarding the anticancer effects of benzimidazole anthelmintics, including albendazole, parbendazole, fenbendazole, mebendazole, oxibendazole, oxfendazole, ricobendazole, and flubendazole in cancer cell lines, animal tumor models, and clinical trials. This review provides valuable information on how to improve the quality of life in patients with cancers by increasing the treatment options and decreasing side effects from conventional therapy.

Quercetin reverses docetaxel resistance in prostate cancer via androgen receptor and PI3K/Akt signaling pathways

Docetaxel is the first-line chemotherapy agent for metastatic prostate cancer. However, the emergence of resistance diminishes its efficacy and limits the survival benefit. Quercetin is a dietary flavonoid which has been shown to have multiple anti-cancer effects. Also, quercetin has been reported to reverse chemo-resistance in many other cancers. This study was to determine whether quercetin could reverse docetaxel resistance in prostate cancer cells and xenograft models, thereby exploring the underlying mechanism. Depending on the docetaxel-resistant cells (LNCaP/R, PC-3/R) which were established from docetaxel-sensitive cells (LNCaP, PC-3), it was demonstrated that quercetin could reverse docetaxel resistance in prostate cancer on proliferation, colony formation, migration, invasion and apoptosis. Although single docetaxel application had little effect on docetaxel-resistant cells, combining docetaxel with quercetin was significantly effective. Combination therapy could maximally inhibited PI3K/Akt pathway and promoted apoptosis. As shown by in-vivo study, xenograft tumors treated by docetaxel with quercetin had poorest growth. Then, to investigate the underlying mechanisms, the differences among parental cells, docetaxel-resistant subclones and quercetin treated resistant subclones were evaluated. It was found that docetaxel-resistant subclones had stronger activation of androgen receptor and PI3K/Akt pathway, more remarkable mesenchymal and stem-like cell phenotypes, and more P-gp expression than that of parental cells. Interestingly, quercetin could reverse these transformations. Our data revealed that quercetin had docetaxel-resistance reversal effect both in vitro and in vivo and provided in-depth support for clinical use of quercetin in docetaxel-resistant prostate cancer.

Protective Effect of Sika Deer (Cervus nippon) Velvet Antler Extract against Cisplatin-Induced Kidney and Liver Injury in a Prostate Cancer PC-3 Cell Xenograft Model

We previously discovered the antioxidant and antiprostate cancer effects of antler extract (AE), but whether it inhibits cisplatin- (Cis-) induced toxicity has not been investigated. In this study, the effect of AE on Cis-induced side effects in the kidney and liver using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide-based cytotoxicity and cell cycle assays in prostate cancer PC-3 cells in vitro is investigated. Furthermore, we used a xenograft mouse model of the same cells to examine the in vivo effects and mechanisms of action. Cis and Cis + AE treatment attenuated prostate cancer cell growth by inducing apoptosis in vitro. Cis + AE stimulated cleaved caspases 3, 7, and 9 and polyadenosine diphosphate ribose polymerase expression. Cis + AE treatment for 1 week significantly increased the superoxide dismutase and catalase antioxidant activity while thiobarbituric acid reactive substances decreased. The histopathological damage and tumor necrosis factor-α, interleukin- (IL-) 1β and IL-6, cyclooxygenase-2, and inducible nitric oxide synthase expression in the kidney and liver tissue decreased. Therefore, AE likely possesses antiprostate cancer activity and inhibits Cis toxicity.

Repositioning of Anti-parasitic Drugs in Cyclodextrin Inclusion Complexes for Treatment of Triple-Negative Breast Cancer

Drug repositioning refers to the identification of new therapeutic indications for drugs already approved. Albendazole and ricobendazole have been used as anti-parasitic drugs for many years; their therapeutic action is based on the inhibition of microtubule formation. Therefore, the study of their properties as antitumor compounds and the design of an appropriate formulation for cancer therapy is an interesting issue to investigate. The selected compounds are poorly soluble in water, and consequently, they have low and erratic bioavailability. In order to improve their biopharmaceutics properties, several formulations employing cyclodextrin inclusion complexes were developed. To carefully evaluate the in vitro and in vivo antitumor activity of these drugs and their complexes, several studies were performed on a breast cancer cell line (4T1) and BALB/c mice. In vitro studies showed that albendazole presented improved antitumor activity compared with ricobendazole. Furthermore, albendazole:citrate-β-cyclodextrin complex decreased significantly 4T1 cell growth both in in vitro and in vivo experiments. Thus, new formulations for anti-parasitic drugs could help to reposition them for new therapeutic indications, offering safer and more effective treatments by using a well-known drug.

Sika deer (Cervus nippon) velvet antler extract attenuates prostate cancer in xenograft model

The present study determines whether antler extract (AE) possesses inhibitory effects in a prostate cancer (PC) xenograft model and explores the underlying mechanism. After therapeutic intervention for two weeks, AE significantly inhibited prostate cancer xenograft tumor growth by 65.08%, and prostate-specific antigen (PSA) and serum dihydrotestosterone (DHT) levels. However, AE increased the serum testosterone level compared to the vehicle control group. Furthermore, our investigation of the inhibitory effects on angiogenesis and epithelial-to-mesenchymal transition (EMT)-related genes revealed that AE downregulated matrix metalloproteinase 2 (MMP)-2, (MMP)-9, vascular endothelial growth factor (VEGF), zinc finger protein (SNAIL1), twist-related protein 1 (TWIST1), and zinc-finger E-box-binding homeobox 1 (ZEB1) in vivo. In contrast, AE increased tissue inhibitor of MMP (TIMP)-1, (TIMP)-2, and E-cadherin. The results suggest that AE possesses potent anti-PC activity, and this is the first report on the anti-PC effect of AE in vivo.

Nanoformulations of albendazole as effective anticancer and antiparasite agents

Initially emerging as a widely used clinical antiparasitic drug, albendazole (ABZ) has been increasingly recognized as an effective anticancer agent due to its outstanding advantage, in other words, low toxicity to normal cells but high effectiveness against parasites and some tumors. The major challenge is its poor water solubility and subsequently low bioavailability. This article thus first reviews the brief achievements in using ABZ to treat parasites and cancers, and summarizes the basic mechanisms of action of ABZ. Then this article critically reviews recent nanotechnological strategies, in other words, formulating/conjugating it with carriers into nanoformulations, in practices of improving aqueous solubility and efficacy in treatment of tumors and parasites. Our expert opinions in this field are provided for more effective delivery of ABZ to treat tumors and parasites in vivo.

Targeting hepatocellular carcinoma with piperine by radical-mediated mitochondrial pathway of apoptosis: An in vitro and in vivo study

Redox mediated cancer therapeutics are of immense interest in the recent decade due to their anticancer activity. Piperine is the principal alkaloid of black and long pepper. Although its anticancer activity has been reported in number of cancers , the precise molecular mechanism of action remains to be unravelled. Hence, in this study, for the first time, we delineated the mechanistic insight into the effect of piperine against hepatocellular carcinoma (HCC).MTT analysis determined the dose and time dependent cytotoxicity of piperine against Hep G2 cells. Further molecular studies evidenced the prooxidant property of piperine by inducing H₂O₂ driven mitochondria-mediated apoptosis in Hep G2 cells by inhibiting the peroxide detoxifying enzyme Catalase. Molecular docking and western blotting analysis uncovered the piperine mediated receptor tyrosine kinase inhibition and mitigation of HCC progression. In addition, histological investigations of piperine - treated, DEN-induced HCC rats showed significant prognosis with apoptotic cell death. Whereas,co-treatment of an antioxidant EUK-134 significantly abrogated its chemotherapeutic activity substantiating its radical-mediated anticancer property. Altogether, this study shows that the piperine may be a promising prooxidant drug for the amelioration of hepatocellular carcinoma.

Formation and characterization of Langmuir and Langmuir-Blodgett films of Newkome-type dendrons in presence and absence of a therapeutic compound, for the development of surface mediated drug delivery systems

Organic macromolecules with dendrimeric architectures are polymeric materials potentially useful as nanocarriers for therapeutic drugs. In this work, we evaluate a series of Newkome-type dendrons in Langmuir and Langmuir-Blodgett films as platforms capable of interacting with a potential antitumoral agent. The nanocomposite is proposed as model for the development of surface mediated drug delivery systems. We were successful in the formation and characterization of pure (dendrons) and composite (drug-dendron) stable and reproducible monolayers, and their transfer to solid substrates. A detailed study of topographic characteristics of the generated surfaces by atomic force microscopy was conducted. Furthermore, we probed dendron monolayer films as anchorage surfaces for mammalian cells. Normal cell attachment and proliferation on the surfaces were observed. No evident cytotoxic effects were detected, demonstrating the adequate biocompatibility of the surfaces.

Anthelmintic drug albendazole arrests human gastric cancer cells at the mitotic phase and induces apoptosis

As microtubules have a vital function in the cell cycle, oncologists have developed microtubule inhibitors capable of preventing uncontrolled cell division, as in the case of cancer. The anthelmintic drug albendazole (ABZ) has been demonstrated to inhibit hepatocellular, ovarian and prostate cancer cells via microtubule targeting. However, its activity against human gastric cancer (GC) cells has remained to be determined. In the present study, ABZ was used to treat GC cells (MKN-45, SGC-7901 and MKN-28). A a CCK-8 cell proliferation assay was performed to assess the effects of ABZ on cell viability and cell cycle changes were assessed using flow cytometry. SGC-7901 cells were selected for further study, and flow cytometry was employed to determine the apoptotic rate, immunofluorescence analysis was employed to show changes of the microtubule structure as well as the subcellular localization and expression levels of cyclin B1, and western blot analysis was used to identify the dynamics of microtubule assembly. The expression levels of relevant proteins, including cyclin B1 and Cdc2, the two subunits of mitosis-promoting factor as well as apoptosis-asociated proteins were also assessed by western blot analysis. The results showed that ABZ exerted its anti-cancer activity in GC cell lines by disrupting microtubule formation and function to cause mitotic arrest, which is also associated with the accumulation of cyclin B1, and consequently induces apoptosis.

JD enhances the anti-tumour effects of low-dose paclitaxel on gastric cancer MKN45 cells both in vitro and in vivo

BACKGROUND

Gastric cancer is the third most common cause of cancer mortality worldwide, and paclitaxel (PTX) is one of the most widely used traditional drugs in gastric cancer therapy. However, the response to traditional therapy is limited by acquired chemo-resistance and side effects. Here, we establish a newly designed combination therapy consisting of a compound that is a structural variant of oridonin, i.e. Jesridonin (JD), and low-dose PTX for gastric cancer cells (MKN45) to investigate whether the anti-tumour activity of low-dose PTX could be enhanced when combined with JD.

METHODS

The interaction of JD and low-dose PTX was detected in MKN45 cells using the median-effect analysis method. The synergistic effect on cell viability and apoptosis was measured by MTT assay, colony formation assay, transient transfection, flow cytometry and Western blotting. The synergistic in vivo effect of JD plus low-dose PTX was evaluated in nude mouse xenograft models using H&E and TUNEL staining and Western blotting.

RESULTS

JD plus low-dose PTX showed a synergistic effect, as the combination indexes were less than 1. Additionally, a synergistic anti-proliferative and pro-apoptotic effect was detected for the combination of JD and low-dose PTX. The apoptotic mechanism induced by JD plus PTX revealed that the combination therapy synergistically activated the mitochondrial pathway.

CONCLUSION

Our findings suggest that JD enhances the anti-tumour effect of low-dose PTX on gastric carcinoma cancer cells in both vitro and in vivo, accompanied by activation of the mitochondrial pathway, which may present a more effective therapeutic strategy in gastric cancer treatment.

Causes of genome instability: the effect of low dose chemical exposures in modern society

Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus, genome instability can be defined as an enhanced tendency for the genome to acquire mutations; ranging from changes to the nucleotide sequence to chromosomal gain, rearrangements or loss. This review raises the hypothesis that in addition to known human carcinogens, exposure to low dose of other chemicals present in our modern society could contribute to carcinogenesis by indirectly affecting genome stability. The selected chemicals with their mechanisms of action proposed to indirectly contribute to genome instability are: heavy metals (DNA repair, epigenetic modification, DNA damage signaling, telomere length), acrylamide (DNA repair, chromosome segregation), bisphenol A (epigenetic modification, DNA damage signaling, mitochondrial function, chromosome segregation), benomyl (chromosome segregation), quinones (epigenetic modification) and nano-sized particles (epigenetic pathways, mitochondrial function, chromosome segregation, telomere length). The purpose of this review is to describe the crucial aspects of genome instability, to outline the ways in which environmental chemicals can affect this cancer hallmark and to identify candidate chemicals for further study. The overall aim is to make scientists aware of the increasing need to unravel the underlying mechanisms via which chemicals at low doses can induce genome instability and thus promote carcinogenesis.

Combination of Quercetin and 2-Methoxyestradiol Enhances Inhibition of Human Prostate Cancer LNCaP and PC-3 Cells Xenograft Tumor Growth

Quercetin and 2-Methoxyestradiol (2-ME) are promising anti-cancer substances. Our previous in vitro study showed that quercetin synergized with 2-Methoxyestradiol exhibiting increased antiproliferative and proapoptotic activity in both androgen-dependent LNCaP and androgen-independent PC-3 human prostate cancer cell lines. In the present study, we determined whether their combination could inhibit LNCaP and PC-3 xenograft tumor growth in vivo and explored the underlying mechanism. Human prostate cancer LNCaP and PC-3 cells were inoculated subcutaneously in male BALB/c nude mice. When xenograft tumors reached about 100 mm³, mice were randomly allocated to vehicle control, quercetin or 2-Methoxyestradiol singly treated and combination treatment groups. After therapeutic intervention for 4 weeks, combination treatment of quercetin and 2-ME i) significantly inhibited prostate cancer xenograft tumor growth by 46.8% for LNCaP and 51.3% for PC-3 as compared to vehicle control group, more effective than quercetin (28.4% for LNCaP, 24.8% for PC3) or 2-ME (32.1% for LNCaP, 28.9% for PC3) alone; ii) was well tolerated by BALB/c mice and no obvious toxic reactions were observed; iii) led to higher Bax/Bcl-2 ratio, cleaved caspase-3 protein expression and apoptosis rate; and iv) resulted in lower phosphorylated AKT (pAKT) protein level, vascular endothelial growth factor protein and mRNA expression, microvascular density and proliferation rate than single drug treatment. These effects were more remarkable compared to vehicle group. Therefore, combination of quercetin and 2-ME can serve as a novel clinical treatment regimen owning the potential of enhancing antitumor effect on prostate cancer in vivo and lessening the dose and side effects of either quercetin or 2-ME alone. These in vivo results will lay a further solid basis for subsequent researches on this novel therapeutic regimen in human prostate cancer.

Albumin nanoparticles increase the anticancer efficacy of albendazole in ovarian cancer xenograft model

Background

The poor prognosis of patients with drug resistant ovarian cancer and the lack of targeted therapy have raised the need for alternative treatments. Albendazole (ABZ) is an anti-parasite compound capable of impairing microtubule formation. We hypothesized that ABZ could be repurposed as a potential anti-angiogenic drug due to its potent inhibition of vascular endothelial growth factor (VEGF) in ovarian cancer with ascites. However, the poor aqueous solubility of ABZ limits its potential for cancer therapy. In this study, we have assembled ABZ with bovine serum albumin into nanoparticles with a size range of 7–10 nm (BSA-ABZ) and 200–250 nm (Nab-ABZ). We further examined the anticancer effects of ABZ carrying nanoparticles in ovarian cancer cells, in both in vitro and in vivo models.

Results

Drug release studies demonstrated that about 93% of ABZ was released from BSA-ABZ 10 nm in comparison to 83% from Nab-ABZ 200 nm at pH 7.4 in 8 days. In vitro cell proliferation studies showed that the BSA-ABZ 10 nm exhibited the highest killing efficacy of ovarian cancer cells with surprisingly least toxicity to healthy ovarian epithelial cells. Confocal microscopy and fluorescence activated cell sorting analysis (FACS) revealed more efficient internalization of the BSA-ABZ 10 nm by cancer cells. For in vivo studies, we examined the tumor growth, ascites formation and the expression of VEGF and secreted protein acidic and rich in cysteine (SPARC) in tumor samples and only VEGF in plasma samples. The BSA-ABZ 10 nm reduced the tumor burden significantly (p < 0.02) at a much lower drug dose (10 μg/ml) compare to free drug. Both formulations were capable of suppressing the ascites volume significantly (p < 0.05) and reducing the number of ascites cells. The expression of VEGF and SPARC was also reduced, which indicates the underlying therapeutic mechanism of the ABZ.

Conclusion

Our data suggest that the BSA-ABZ may hold promise for the treatment and control of progression of ovarian cancer with ascites. However further studies are required to examine the efficacy of both the formulations in aggressive models of recurrent ovarian cancer with respect to particle size and dosing parameters.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-015-0082-8) contains supplementary material, which is available to authorized users.

Effects of an antimitotic drug on mechanical behaviours of the cytoskeleton in distinct grades of colon cancer cells

Biomechanical behaviours of cells change during cancer progression due to alterations in the main cytoskeletal proteins. Microtubules play a vital role in mitosis and in supporting the integrity of the cell due to their ability to withstand high compressive loads. Accordingly, microtubule-targeting agents (MTAs) have become one of the most promising classes of drugs in cancer therapy. This study evaluated changes in visco-elastic parameters induced by an appropriate concentration of an antimitotic drug in two different grades of colon cancer cells. Actin microfilaments and microtubules contents in the cells were evaluated by Western blot analysis and fluorescence intensity calculation. Micropipette aspiration experiments showed that the MTA had distinct mechanical effects on different cell lines. The more aggressive the cells, the greater the reduction in elasticity and viscosity. Invasive cells had a higher initial instantaneous Young's modulus than primary cells, but this reduced to approximately one half of the values for primary cells after 48 h of drug treatment. A considerable association was seen between the changes in mechanical properties and the microtubule to F-actin microfilament content ratio, which decreased with MTA treatment.

2-Methoxyestradiol inhibits bleomycin-induced systemic sclerosis through suppression of fibroblast activation

BACKGROUND

The most dominant feature of systemic sclerosis (SSc) is fibrosis, which is caused by overproduction of collagen by fibroblasts. 2-Methoxyestradiol (2-ME) has exhibited disease-modifying activity in animal models of rheumatoid arthritis and autoimmune encephalomyelitis and inhibitory effect in cell proliferation and collagen synthesis. Therefore, we hypothesized that 2-ME may exhibit antifibrotic effect in SSc.

OBJECTIVE

To investigate the antifibrotic effect of 2-ME in SSc.

METHODS

We established a bleomycin-induced SSc mice model by injection with bleomycin daily for 21 days. 2-ME (100mg/kg/d) was simultaneously administered for 14 days. On the end of Week1 (W1), W2, W3 and W4, skins and lungs were collected for histological examination and analysis of hydroxyproline content and mRNA level of α1(I) procollagen (COL1A1) and COL1A2. In skin fibroblasts derived from SSc patients and healthy subjects treated with 2-ME (1, 5, or 25 μM), we examined cell proliferation, expression of α-smooth muscle actin (SMA) and mRNA level of COL1A1, COL1A2, COL3A1, matrix metalloproteinase(MMP)-1 and tissue inhibitors of MMP (TIMP)-1.

RESULTS

We found reduced dermal thickness and lung fibrosis and decreased hydroxyproline content and mRNA level of COL1A1 and COL1A2 in skin and lung in SSc mice treated with 2-ME. In cell study, we observed a dose- and time-dependent inhibitory effect on proliferation of SSc fibroblasts by 2-ME. We also detected reduced α-SMA expression, decreased mRNA level of COL1A1, COL1A2, COL3A1 and TIMP-1, and increased mRNA level of MMP-1 in SSc fibroblasts treated with 2-ME.

CONCLUSION

2-ME could suppress SSc tissue fibrosis, which may be attributable to its inhibitory effect on the excessive proliferation, differentiation and production of collagen in fibroblasts. 2-ME is rising as a prospective agent for control of fibrosis in SSc.

2-Methoxyestradiol synergizes with sorafenib to suppress hepatocellular carcinoma by simultaneously dysregulating hypoxia-inducible factor-1 and -2

Sorafenib is the approved systemic drug of choice for advanced hepatocellular carcinoma (HCC), but has demonstrated limited benefits because of drug resistance. 2-Methoxyestradiol (2ME2) has been shown to be a promising anticancer drug against various types of cancers and acts by dysregulating hypoxia-inducible factor (HIF)-1. Hypoxic cancer cells are extremely resistant to therapies since they elicit strong survival ability due to the cellular adaptive response to hypoxia, which is controlled by HIF-1 and HIF-2. The present study has demonstrated that sorafenib downregulated the expression of HIF-1α, making the hypoxic response switch from HIF-1α- to HIF-2α-dependent pathways, resulting in upregulation of HIF-2α, which contributes to the insensitivity of hypoxic HCC cells to sorafenib. HIF-2α played a dominant role in regulating VEGF, thus sorafenib in turn increased the expression of VEGF (a downstream molecule of both HIF-1 and HIF-2) and cyclin D1 (a downstream molecule of HIF-2), but reduced the expression of LDHA (a downstream molecule of HIF-1), in hypoxic HCC cells. 2ME2 significantly reduced the expression of both HIF-1α and HIF-2α, and their downstream molecules, VEGF, LDHA and cyclin D1, rendering hypoxic HCC cells to increased sensitivity to 2ME2. 2ME2 also inhibited the nuclear translocation of HIF-1α and HIF-2α proteins, but had no effect on their mRNA expression. 2M2 synergized with sorafenib to suppress the proliferation and induction of apoptosis of HCC cells in vitro and in vivo, and inhibited tumoral angiogenesis. These results indicate that 2ME2 given in combination with sorafenib acts synergistically for treating HCC.

Repurposing Drugs in Oncology (ReDO)-mebendazole as an anti-cancer agent

Mebendazole, a well-known anti-helminthic drug in wide clinical use, has anti-cancer properties that have been elucidated in a broad range of pre-clinical studies across a number of different cancer types. Significantly, there are also two case reports of anti-cancer activity in humans. The data are summarised and discussed in relation to suggested mechanisms of action. Based on the evidence presented, it is proposed that mebendazole would synergise with a range of other drugs, including existing chemotherapeutics, and that further exploration of the potential of mebendazole as an anti-cancer therapeutic is warranted. A number of possible combinations with other drugs are discussed in the Appendix.

2-methoxyestradiol and disorders of female reproductive tissues

2-Methoxyestradiol (2ME) is an endogenous metabolite of 17β-estradiol. Once thought of as a mere degradation product, 2ME has gained attention as an important component of reproductive physiology and as a therapeutic agent in reproductive pathologies such as preeclampsia, endometriosis, infertility, and cancer. In this review, we discuss the involvement of 2ME in reproductive pathophysiology and summarize its known mechanisms of action: microtubule disruption, inhibition of angiogenesis and stimulation of apoptosis. Currently, the clinical uses of 2ME as a single agent are limited due to its poor water solubility and thus low bioavailability; however, 2ME analogs and derivatives have been recently developed and tested as cancer treatments. Despite some isolated success stories and ongoing research, 2ME derivatives have not yet provided the expected results. The adjuvant use of 2ME derivatives with chemotherapeutic agents is hindered by their intrinsic toxicity confounding the unwanted secondary effects of chemotherapy. However, due to the well-tested tolerance of the body to high doses of native 2ME, it may the combination of native 2ME with conventional treatments that will offer novel clinically relevant regimens for cancer and other reproductive disorders.

Up-regulation of survivin by AKT and hypoxia-inducible factor 1α contributes to cisplatin resistance in gastric cancer

This study investigated the contribution of survivin and its upstream regulators, AKT and hypoxia-inducible factor 1α (HIF-1α), to the resistance of gastric cancer cells to cisplatin (CDDP). We found that over-expression of survivin increased the resistance of SGC7901 and BGC823 gastric cancer cells to CDDP. Its over-expression abrogated CDDP-induced inhibition of cell proliferation and CDDP-induced cell apoptosis. In contrast, down-regulation of survivin expression using small hairpin RNA (shRNA) vectors and the small-molecule inhibitor YM155, or inhibition of survivin function using a recombinant cell-permeable dominant-negative survivin protein (dNSur9), promoted CDDP-induced apoptosis. CDDP-resistant sub-lines generated from the parental SGC7901 and BGC823 cells by exposure to increasing concentrations of CDDP expressed higher levels of HIF-1α and survivin in response to hypoxia, and higher levels of phosphorylated AKT (pAKT). Specific inhibition of AKT reduced the expression of HIF-1α and survivin, whereas specific inhibition or depletion of HIF-1α reduced survivin expression but had no effect on the expression of phosphorylated AKT. The expression levels of survivin affected the therapeutic efficacy of CDDP in treating gastric tumors in mice. Specific inhibition of survivin, AKT and HIF-1α enhanced the sensitivity of CDDP-resistant cells to CDDP. Specific inhibition of survivin, AKT and HIF-1α synergized with CDDP to suppress the growth of gastric tumors that had been engineered to overexpress survivin. In summary, the results provide evidence that up-regulation of survivin by AKT and HIF-1α contributes to CDDP resistance, indicating that inhibition of these pathways may be a potential strategy for overcoming CDDP resistance in the treatment of gastric cancer.