Flubendazole demonstrates valid antitumor effects by inhibiting STAT3 and activating autophagy

Synergistic intravesical instillation for bladder cancer: CRISPR-Cas13a and fenbendazole combination therapy

BACKGROUND

CRISPR-Cas13a is renowned for its precise and potent RNA editing capabilities in cancer therapy. While various material systems have demonstrated efficacy in supporting CRISPR-Cas13a to execute cellular functions in vitro efficiently and specifically, the development of CRISPR-Cas13a-based therapeutic agents for intravesical instillation in bladder cancer (BCa) remains unexplored.

METHODS

In this study, we introduce a CRISPR-Cas13a nanoplatform, which effectively inhibits PDL1 expression following intravesical instillation. This system utilizes a fusion protein CAST, created through the genetic fusion of CRISPR-Cas13 and the transmembrane peptide TAT. CAST acts as a potent transmembrane RNA editor and is assembled with the transepithelial delivery carrier fluorinated chitosan (FCS). Upon intravesical administration into the bladder, the CAST-crRNAa/FCS nanoparticles (NPs) exhibit remarkable transepithelial capabilities, significantly suppressing PDL1 expression in tumor tissues.To augment immune activation within the tumor microenvironment, we integrated a fenbendazole (FBZ) intravesical system (FBZ@BSA/FCS NPs). This system is formulated through BSA encapsulation followed by FCS coating, positioning FBZ as a powerful chemo-immunological agent.

RESULTS

In an orthotropic BCa model, the FBZ@BSA/FCS NPs demonstrated pronounced tumor cell apoptosis, synergistically reduced PDL1 expression, and restructured the immune microenvironment. This culminated in an enhanced synergistic intravesical instillation approach for BCa. Consequently, our study unveils a novel RNA editor nanoagent formulation and proposes a potential synergistic therapeutic strategy. This approach significantly bolsters therapeutic efficacy, holding promise for the clinical translation of CRISPR-Cas13-based cancer perfusion treatments.

Investigating the therapeutic promise of Drug-Repurposed-Loaded Nanocarriers: A pioneering strategy in advancing colorectal cancer treatment

Globally, colorectal cancer is a major health problem that ranks in third place in terms of occurrences and second in terms of mortality worldwide. New cases increase annually, with the absence of effective therapies, especially for metastatic colorectal cancer, emphasizing the need for novel therapeutic approaches. Although conventional treatments are commonly used in oncotherapy, their success rate is low, which leads to the exploration of novel technologies. Recent efforts have focused on developing safe and efficient cancer nanocarriers. With their nanoscale properties, nanocarriers have the potential to utilize internal metabolic modifications amid cancer cells and healthy cells. Drug repurposing is an emerging strategy in cancer management as it is a faster, cheaper, and safer method than conventional drug development. However, most repurposed drugs are characterized by low-key pharmacokinetic characteristics, such as poor aqueous solubility, permeability, retention, and bioavailability. Nanoparticle formulations and delivery have expanded over the past few decades, creating opportunities for drug repurposing and promises as an advanced cancer modality. This review provides a concise and updated overview of colorectal cancer treatment regimens and their therapeutic limitations. Furthermore, the chemotherapeutic effect of various FDA-approved medications, including statins, non-steroidal anti-inflammatory drugs, antidiabetic and anthelmintic agents, and their significance in colorectal cancer management. Along with the role of various nanocarrier systems in achieving the desired therapeutic outcomes of employing these redefined drugs.

Genistein alleviates doxorubicin-induced cardiomyocyte autophagy and apoptosis via ERK/STAT3/c-Myc signaling pathway in rat model

Doxorubicin (Dox) is a highly effective anti-neoplastic agent. Still, its utility in the clinic has been hindered by toxicities, including vomiting, hematopoietic suppression and nausea, with cardiotoxicity being the most serious side effect. Genistein (Gen) is a natural product with extensive biological effects, including anti-oxidation, anti-tumor, and cardiovascular protection. This study evaluated whether Gen protected the heart from Dox-induced cardiotoxicity and explored the underlying mechanisms. Male Sprague-Dawley (SD) rats were categorized into control (Ctrl), genistein (Gen), doxorubicin (Dox), genistein 20 mg/kg/day + doxorubicin (Gen20 + Dox) and genistein 40 mg/kg/day + doxorubicin (Gen40 + Dox) groups. Six weeks after injection, immunohistochemistry (IHC), transmission electron microscopy (TEM), and clinical cardiac function analyses were performed to evaluate the effects of Dox on cardiac function and structural alterations. Furthermore, each heart histopathological lesions were given a score of 0-3 in compliance with the articles for statistical analysis. In addition, molecular and cellular response of H9c2 cells toward Dox were evaluated through western blotting, Cell Counting Kit-8 (CCK8), AO staining and calcein AM/PI assay. Dox (5 μM in vitro and 18 mg/kg in vivo) was used in this study. In vivo, low-dose Gen pretreatment protected the rat against Dox-induced cardiac dysfunction and pathological remodeling. Gen inhibited extracellular signal-regulated kinase1/2 (ERK1/2)'s phosphorylation, increased the protein levels of STAT3 and c-Myc, and decreased the autophagy and apoptosis of cardiomyocytes. U0126, a MEK1/2 inhibitor, can mimic the effect of Gen in protecting against Dox-induced cytotoxicity both in vivo and in vitro. Molecular docking analysis showed that Gen forms a stable complex with ERK1/2. Gen protected the heart against Dox-induced cardiomyocyte autophagy and apoptosis through the ERK/STAT3/c-Myc signaling pathway.

Flubendazole suppresses VEGF-induced angiogenesis in HUVECs and exerts antitumor effects in PC-3 cells

Flubendazole, an FDA-approved anthelmintic, has been predicted to show strong VEGFR2 inhibitory activity in silico screening combined with in vitro experimental validation, and it has shown anti-cancer effects on some human cancer cell lines, but little is known about the anti-angiogenesis effects and anti-prostate cancer effects. In this study, we analyzed the binding modes and kinetic analysis of flubendazole with VEGFR2 and first demonstrated that flubendazole suppressed VEGF-stimulated cell proliferation, wound-healing migration, cell invasion and tube formation of HUVEC cells, and decreased the phosphorylation of extracellular signal-regulated kinase and serine/threonine kinase Akt, which are the downstream proteins of VEGFR2 that are important for cell growth. What's more, our results showed that flubendazole decreased PC-3 cell viability and proliferation ability, and suppressed PC-3 cell wound healing migration and invasion across a Matrigel-coated Transwell membrane in a concentration-dependent manner. The antiproliferative effects of flubendazole were due to induction of G2-M phase cell cycle arrest in PC-3 cells with decreasing expression of the Cyclin D1 and induction of cell apoptosis with the number of apoptotic cells increased after flubendazole treatment. These results indicated that flubendazole could exert anti-angiogenic and anticancer effects by inhibiting cell cycle and inducing cell apoptosis.

Fusobacterium nucleatum and its metabolite hydrogen sulfide alter gut microbiota composition and autophagy process and promote colorectal cancer progression

IMPORTANCE

Colorectal cancer (CRC) is the second most common cancer in the world; the main treatment for CRC is immunosuppressive therapy, but this therapy is only effective for a small percentage of CRC patients, so there is an urgent need for a treatment with fewer side effects and higher efficacy. This study demonstrated that Fusobacterium nucleatum with increased abundance in CRC can regulate the autophagy process and disrupt normal intestinal microbiota by producing hydrogen sulfide, factors that may be involved in the development and progression of CRC. This study may provide a reference for future CRC treatment options that are efficient and have fewer side effects.

Flubendazole Enhances the Inhibitory Effect of Paclitaxel via HIF1α/PI3K/AKT Signaling Pathways in Breast Cancer

Paclitaxel, a natural anticancer drug, is widely recognized and extensively utilized in the treatment of breast cancer (BC). However, it may lead to certain side effects or drug resistance. Fortunately, combination therapy with another anti-tumor agent has been explored as an option to improve the efficacy of paclitaxel in the treatment of BC. Herein, we first evaluated the synergistic effects of paclitaxel and flubendazole through combination index (CI) calculations. Secondly, flubendazole was demonstrated to synergize paclitaxel-mediated BC cell killing in vitro and in vivo. Moreover, we discovered that flubendazole could reverse the drug resistance of paclitaxel-resistant BC cells. Mechanistically, flubendazole was demonstrated to enhance the inhibitory effect of paclitaxel via HIF1α/PI3K/AKT signaling pathways. Collectively, our findings demonstrate the effectiveness of flubendazole in combination with paclitaxel for treating BC, providing an insight into exploiting more novel combination therapies for BC in the future.

Repurposing approved non-oncology drugs for cancer therapy: a comprehensive review of mechanisms, efficacy, and clinical prospects

Cancer poses a significant global health challenge, with predictions of increasing prevalence in the coming years due to limited prevention, late diagnosis, and inadequate success with current therapies. In addition, the high cost of new anti-cancer drugs creates barriers in meeting the medical needs of cancer patients, especially in developing countries. The lengthy and costly process of developing novel drugs further hinders drug discovery and clinical implementation. Therefore, there has been a growing interest in repurposing approved drugs for other diseases to address the urgent need for effective cancer treatments. The aim of this comprehensive review is to provide an overview of the potential of approved non-oncology drugs as therapeutic options for cancer treatment. These drugs come from various chemotherapeutic classes, including antimalarials, antibiotics, antivirals, anti-inflammatory drugs, and antifungals, and have demonstrated significant antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties. A systematic review of the literature was conducted to identify relevant studies on the repurposing of approved non-oncology drugs for cancer therapy. Various electronic databases, such as PubMed, Scopus, and Google Scholar, were searched using appropriate keywords. Studies focusing on the therapeutic potential, mechanisms of action, efficacy, and clinical prospects of repurposed drugs in cancer treatment were included in the analysis. The review highlights the promising outcomes of repurposing approved non-oncology drugs for cancer therapy. Drugs belonging to different therapeutic classes have demonstrated notable antitumor effects, including inhibiting cell proliferation, promoting apoptosis, modulating the immune response, and suppressing metastasis. These findings suggest the potential of these repurposed drugs as effective therapeutic approaches in cancer treatment. Repurposing approved non-oncology drugs provides a promising strategy for addressing the urgent need for effective and accessible cancer treatments. The diverse classes of repurposed drugs, with their demonstrated antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties, offer new avenues for cancer therapy. Further research and clinical trials are warranted to explore the full potential of these repurposed drugs and optimize their use in treating various cancer types. Repurposing approved drugs can significantly expedite the process of identifying effective treatments and improve patient outcomes in a cost-effective manner.

Anti-cancer effect of fenbendazole-incorporated PLGA nanoparticles in ovarian cancer

OBJECTIVE

Fenbendazole (FZ) has potential anti-cancer effects, but its poor water solubility limits its use for cancer therapy. In this study, we investigated the anti-cancer effect of FZ with different drug delivery methods on epithelial ovarian cancer (EOC) in both in vitro and in vivo models.

METHODS

EOC cell lines were treated with FZ and cell proliferation was assessed. The effect of FZ on tumor growth in cell line xenograft mouse model of EOC was examined according to the delivery route, including oral and intraperitoneal administration. To improve the systemic delivery of FZ by converting fat-soluble drugs to hydrophilic, we prepared FZ-encapsulated poly(D,L-lactide-co-glycolide) acid (PLGA) nanoparticles (FZ-PLGA-NPs). We investigated the preclinical efficacy of FZ-PLGA-NPs by analyzing cell proliferation, apoptosis, and in vivo models including cell lines and patient-derived xenograft (PDX) of EOC.

RESULTS

FZ significantly decreased cell proliferation of both chemosensitive and chemoresistant EOC cells. However, in cell line xenograft mouse models, there was no effect of oral FZ treatment on tumor reduction. When administered intraperitoneally, FZ was not absorbed but aggregated in the intraperitoneal space. We synthesized FZ-PLGA-NPs to obtain water solubility and enhance drug absorption. FZ-PLGA-NPs significantly decreased cell proliferation in EOC cell lines. Intravenous injection of FZ-PLGA-NP in xenograft mouse models with HeyA8 and HeyA8-MDR significantly reduced tumor weight compared to the control group. FZ-PLGA-NPs showed anti-cancer effects in PDX model as well.

CONCLUSION

FZ-incorporated PLGA nanoparticles exerted significant anti-cancer effects in EOC cells and xenograft models including PDX. These results warrant further investigation in clinical trials.

Sam68 promotes osteogenic differentiation of aortic valvular interstitial cells by TNF-α/STAT3/autophagy axis

Calcified aortic valve disease (CAVD) is a major non-rheumatic heart valve disease in the world, with a high mortality rate and without suitable pharmaceutical therapy due to its complex mechanisms. Src-associated in mitosis 68-KD (Sam68), an RNA binding protein, has been reported as a signaling adaptor in numerous signaling pathways (Huot in Mol Cell Biol, 29(7), 1933-1943, 2009), particularly in inflammatory signaling pathways. The effects of Sam68 on the osteogenic differentiation process of hVICs and its regulation on signal transducer and activator of transcription 3 (STAT3) signaling pathway have been investigated in this study. Human aortic valve samples detection found that Sam68 expression was up-regulated in human calcific aortic valves. We used tumor necrosis factor α (TNF-α) as an activator for osteogenic differentiation in vitro and the result indicated that Sam68 was highly expressed after TNF-α stimulation. Overexpression of Sam68 promoted osteogenic differentiation of hVICs while Sam68 knockdown reversed this effect. Sam68 interaction with STAT3 was predicted by using String database and was verified in this study. Sam68 knockdown reduced phosphorylation of STAT3 activated by TNF-α and the downstream gene expression, which further influenced autophagy flux in hVICs. STAT3 knockdown alleviated the osteogenic differentiation and calcium deposition promoted by Sam68 overexpression. In conclusion, Sam68 interacts with STAT3 and participates in its phosphorylation to promote osteogenic differentiation of hVICs to induce valve calcification. Thus, Sam68 may be a new therapeutic target for CAVD. Regulatory of Sam68 in TNF-α/STAT3/Autophagy Axis in promoting osteogenesis of hVICs.

Immune Checkpoint Inhibitors, Small-Molecule Immunotherapies and the Emerging Role of Neutrophil Extracellular Traps in Therapeutic Strategies for Head and Neck Cancer

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of many cancer types, including head and neck cancers (HNC). When checkpoint and partner proteins bind, these send an "off" signal to T cells, which prevents the immune system from destroying tumor cells. However, in HNC, and indeed many other cancers, more people do not respond and/or suffer from toxic effects than those who do respond. Hence, newer, more effective approaches are needed. The challenge to durable therapy lies in a deeper understanding of the complex interactions between immune cells, tumor cells and the tumor microenvironment. This will help develop therapies that promote lasting tumorlysis by overcoming T-cell exhaustion. Here we explore the strengths and limitations of current ICI therapy in head and neck squamous cell carcinoma (HNSCC). We also review emerging small-molecule immunotherapies and the growing promise of neutrophil extracellular traps in controlling tumor progression and metastasis.

The opportunities and challenges in immunotherapy: Insights from the regulation of PD-L1 in cancer cells

The immunosuppressive molecule programmed death-ligand 1 (PD-L1) is frequently upregulated in human cancers. Binding of PD-L1 to its receptor, programmed death-1 (PD-1), on activated T cells facilitates cancer cells to evade the host immune system. Antibody-based PD-1/PD-L1 inhibitors can inhibit PD-1/PD-L1 interaction allowing reactivate cytotoxic T cells to eradicate advanced cancer cells. However, the majority of cancer patients fail to respond to anti-PD-1/PD-L1 therapies and the molecular mechanisms for this remain poorly understood. Recent studies show that PD-L1 expression level on tumor cells affect the clinical efficacy of immune checkpoint therapies. Thus, furthering our understanding of the regulatory mechanisms of PD-L1 expression in cancer cells will be critical to improve clinical response rates and the efficacy of PD-1/PD-L1 immune therapies. Here we review recent studies, primarily focusing on the mechanisms that regulate PD-L1 expression at the transcriptional, post-transcriptional and protein level, with the purpose to drive the development of more targeted and effective anti-PD-1/PD-L1 cancer therapies.

Identification of the prognostic biomarkers and their correlations with immune infiltration in colorectal cancer through bioinformatics analysis and in vitro experiments

Colorectal cancer (CRC) is the third most diagnosed malignancy and the second leading cause of cancer death. The objective was to identify novel hub genes that were helpful for prognosis and targeted therapy in CRC. GSE23878, GSE24514, GSE41657, GSE81582 were filtered from the gene expression omnibus (GEO). Differentially expressed genes (DEGs) were identified through GEO2R, which were enriched in the GO term and KEGG pathway in DAVID. PPI network was constructed and analyzed using STRING and hub genes were screened out. The relationships between hub genes and prognoses in CRC were evaluated in GEPIA based on the cancer genome atlas (TCGA) and genotype-tissue expression (GTEx). The transcription factors and miRNA-mRNA interaction networks for hub genes were performed using miRnet and miRTarBase. The relationship between hub genes and tumor-infiltrating lymphocytes were analyzed in TIMER. The protein levels of hub genes were identified in HPA. The expression levels of hub gene in CRC and its effect on the biological effect of CRC cells were identified in vitro. As hub genes, the mRNA levels of BIRC5, CCNB1, KIF20A, NCAPG, and TPX2 were highly expressed in CRC and had excellent prognostic value. The BIRC5, CCNB1, KIF20A, NCAPG, and TPX2 were closely associated with transcription factors, miRNAs, tumor-infiltrating lymphocytes, suggesting their involvement in the regulation of CRC. BIRC5 highly expressed in CRC tissues and cells, and promoted the proliferation, migration, and invasion of CRC cells. BIRC5, CCNB1, KIF20A, NCAPG, and TPX2 are hub genes that serve as promising prognostic biomarkers in CRC. BIRC5 plays an important role in the development and progression of CRC.

Flubendazole exhibits anti-glioblastoma effect by inhibiting STAT3 and promoting cell cycle arrest

Glioblastoma multiforme (GBM) belongs to most aggressive and invasive primary brain tumor in adults whose prognosis and survival remains poor. Potential new treatment modalities include targeting the cytoskeleton. In our study, we demonstrated that repurposed drug flubendazole (FLU) significantly inhibits proliferation and survival of GBM cells. FLU exerted its effect by affecting microtubule structure and our results also suggest that FLU influences tubulins expression to a certain degree. Moreover, FLU effects decreased activation of STAT3 and also partially inhibited its expression, leading to upregulation of p53 signaling pathway and subsequent cell cycle arrest at G2/M phase as well as caspase-dependent cell death in GBM cells. These results suggest FLU as a promising agent to be used in GBM treatment and prompting further testing of its effects on GBM.

Anthelmintic Drugs as Emerging Immune Modulators in Cancer

Despite recent advances in treatment approaches, cancer is still one of the leading causes of death worldwide. Restoration of tumor immune surveillance represents a valid strategy to overcome the acquired resistance and cytotoxicity of conventional therapies in oncology and immunotherapeutic drugs, such as immune checkpoint inhibitors and immunogenic cell death inducers, and has substantially progressed the treatment of several malignancies and improved the clinical management of advanced disease. Unfortunately, because of tumor-intrinsic and/or -extrinsic mechanisms for escaping immune surveillance, only a fraction of patients clinically respond to and benefit from cancer immunotherapy. Accumulating evidence derived from studies of drug repositioning, that is, the strategy to identify new uses for approved or investigational drugs that are outside the scope of the original medical indication, has suggested that some anthelmintic drugs, in addition to their antineoplastic effects, exert important immunomodulatory actions on specific subsets of immune cell and related pathways. In this review, we report and discuss current knowledge on the impact of anthelmintic drugs on host immunity and their potential implication in cancer immunotherapy.

Influence of Co-amorphization on the Physical Stability and Dissolution Performance of an Anthelmintic Drug Flubendazole

In this work, the co-amorphization approach was applied to flubendazole (FluBZ), resulting in the formation of two novel solid forms of FluBZ with l-phenylalanine (Phe) and l-tryptophan (Trp). A variety of physicochemical techniques have been used to describe new systems, including powder X-ray diffraction, thermal methods, infrared spectroscopy, and scanning electron microscopy. Co-amorphization has been shown to suppress crystallization tendency and considerably increase the shelf-life storage of amorphous flubendazole solid across a wide range of relative humidities. The dissolution behavior of the amorphous forms in biorelevant media at pH = 1.6, pH = 6.5, and 37 °C has been studied in terms of C_max (maximum FluBZ concentration), T_max (time to attain peak drug concentration), and AUC (concentration area under the curve during dissolution). At pH = 6.5, a continuous supersaturation and the highest AUC value of all examined systems were observed for the FluBZ-Phe (1:1) system. The phase solubility diagrams revealed that the reason for the better dissolution performance of FluBZ-Phe (1:1) at pH = 6.5 is a complexation between the components in a solution. This work highlights the applicability of co-amorphous systems in improving the physical stability and dissolution performance of drug compounds with poor biopharmaceutical characteristics.

Drug Repurposing Flubendazole to Suppress Tumorigenicity via PCSK9-dependent Inhibition and Potentiate Lenvatinib Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal malignant cancers across the world. It has a poor prognosis and lacks effective therapies, especially for patients with advanced-stage cancer, indicating an urgent need for new therapies and novel therapeutic targets. Here, by screening the U.S. Food and Drug Administration drug library against HCC cell lines, we identified that flubendazole, a traditional anthelmintic drug, could prominently suppress HCC cells in vivo and in vitro. RNA sequence analysis and cellular thermal shift assays showed that flubendazole reduced the expression of PCSK9 protein by direct targeting. The increased expression of PCSK9 in HCC tissues was demonstrated to be correlated with poor prognosis, and the inhibitory ability of flubendazole was selectively dependent on PCSK9 expression. PCSK9 knockdown abolished the antitumor effects of flubendazole in HCC. Mechanistically, flubendazole inhibited the Hedgehog signaling pathway induced by PCSK9, resulting in the downregulation of smoothened (SMO) and GLI Family Zinc Finger 1 (Gli1). Moreover, combining flubendazole with lenvatinib was found more effective than administering lenvatinib only for HCC treatment in vivo and in vitro. These findings reveal the therapeutic potential of flubendazole against HCC and provide clues on new repurposed drugs and targets for cancer treatment.

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.

Deconvoluting the complexity of autophagy in colorectal cancer: From crucial pathways to targeted therapies

Colorectal cancer (CRC) is a common gastrointestinal tumor with a high degree of malignancy, and most clinical cases are diagnosed at an advanced stage, which has unfortunately missed an opportunity for surgery; therefore, elucidation of the crucial pathways of CRC development and discovery of targeted therapeutic strategies should be anticipated. Autophagy, which is an evolutionarily highly conserved catabolic process, may promote tumorigenesis and development of CRC. On the contrary, autophagy can trigger programmed cell death to inhibit CRC progression. Correspondingly, several targeted therapeutic strategies have been reported in CRC, including small-molecule compounds, polypeptides, non-coding RNAs, photodynamic, and adjuvant therapies. Thus, in this review, we focus on summarizing the crucial pathways of autophagy in CRC, and further discuss the current therapeutic strategies targeting autophagy. Together, these findings may shed light on the key regulatory mechanisms of autophagy and provide more promising therapeutic approaches for the future CRC therapies.

Anti-cancer effects of fenbendazole on 5-fluorouracil-resistant colorectal cancer cells

Benzimidazole anthelmintic agents have been recently repurposed to overcome cancers resistant to conventional therapies. To evaluate the anti-cancer effects of benzimidazole on resistant cells, various cell death pathways were investigated in 5-fluorouracil-resistant colorectal cancer cells. The viability of wild-type and 5-fluorouracil-resistant SNU-C5 colorectal cancer cells was assayed, followed by Western blotting. Flow cytometry assays for cell death and cell cycle was also performed to analyze the anti-cancer effects of benzimidazole. When compared with albendazole, fenbendazole showed higher susceptibility to 5-fluorouracil-resistant SNU-C5 cells and was used in subsequent experiments. Flow cytometry revealed that fenbendazole significantly induces apoptosis as well as cell cycle arrest at G2/M phase on both cells. When compared with wild-type SNU-C5 cells, 5-fluorouracil-resistant SNU-C5 cells showed reduced autophagy, increased ferroptosis and ferroptosis-augmented apoptosis, and less activation of caspase-8 and p53. These results suggest that fenbendazole may be a potential alternative treatment in 5-fluorouracil-resistant cancer cells, and the anticancer activity of fenbendazole does not require p53 in 5-fluorouracil-resistant SNU-C5 cells.

Drug Repurposing to Enhance Antitumor Response to PD-1/PD-L1 Immune Checkpoint Inhibitors

Monoclonal antibodies targeting the PD-1/PD-L1 immune checkpoint have considerably improved the treatment of some cancers, but novel drugs, new combinations, and treatment modalities are needed to reinvigorate immunosurveillance in immune-refractory tumors. An option to elicit antitumor immunity against cancer consists of using approved and marketed drugs known for their capacity to modulate the expression and functioning of the PD-1/PD-L1 checkpoint. Here, we have reviewed several types of drugs known to alter the checkpoint, either directly via the blockade of PD-L1 or indirectly via an action on upstream effectors (such as STAT3) to suppress PD-L1 transcription or to induce its proteasomal degradation. Specifically, the repositioning of the approved drugs liothyronine, azelnidipine (and related dihydropyridine calcium channel blockers), niclosamide, albendazole/flubendazole, and a few other modulators of the PD-1/PD-L1 checkpoint (repaglinide, pimozide, fenofibrate, lonazolac, propranolol) is presented. Their capacity to bind to PD-L1 or to repress its expression and function offer novel perspectives for combination with PD-1 targeted biotherapeutics. These known and affordable drugs could be useful to improve the therapy of cancer.

Drug repurposing: An emerging strategy in alleviating skin cancer

Skin cancer is one of the most common forms of cancer. Several million people are estimated to have affected with this condition worldwide. Skin cancer generally includes melanoma and non-melanoma with the former being the most dangerous. Chemotherapy has been one of the key therapeutic strategies employed in the treatment of skin cancer, especially in advanced stages of the disease. It could be also used as an adjuvant with other treatment modalities depending on the type of skin cancer. However, there are several shortfalls associated with the use of chemotherapy such as non-selectivity, tumour resistance, life-threatening toxicities, and the exorbitant cost of medicines. Furthermore, new drug discovery is a lengthy and costly process with minimal likelihood of success. Thus, drug repurposing (DR) has emerged as a new avenue where the drug approved formerly for the treatment of one disease can be used for the treatment of another disease like cancer. This approach is greatly beneficial over the de novo approach in terms of time and cost. Moreover, there is minimal risk of failure of repurposed therapeutics in clinical trials. There are a considerable number of studies that have reported on drugs repurposed for the treatment of skin cancer. Thus, the present manuscript offers a comprehensive overview of drugs that have been investigated as repurposing candidates for the efficient treatment of skin cancers mainly melanoma and its oncogenic subtypes, and non-melanoma. The prospects of repurposing phytochemicals against skin cancer are also discussed. Furthermore, repurposed drug delivery via topical route and repurposed drugs in clinical trials are briefed. Based on the findings from the reported studies discussed in this manuscript, drug repurposing emerges to be a promising approach and thus is expected to offer efficient treatment at a reasonable cost in devitalizing skin cancer.

The novel FGFR inhibitor F1-7 induces DNA damage and cell death in colon cells

BACKGROUND

Fibroblast growth factor receptor (FGFR) signaling influenced tumour occurrence and development. Overexpression of FGFR had been observed in many types of cancers, including colon cancer. FGFR inhibitor is considered to be effective in treating colon cancer patients.

METHODS

First, the kinase inhibition rate was determined. MTT, western blotting, colony formation, EdU and comet assays were performed to evaluate the anti-tumour effects of F1-7 in vitro. RNA-seq and bioinformatics analysis were used for further verification. Additionally, a xenograft model was generated to investigate the anti-tumour effect of F1-7.

RESULTS

F1-7 can inhibit the proliferation of colon cancer cells in vitro. It could significantly inhibit FGFR phosphorylation and its downstream signaling pathway. Whole-genome RNA-seq analysis found that the changed genes were not only functionally focused on MAPK signaling pathway but also related to cell apoptosis and ferroptosis. Experimental evidence demonstrated that F1-7 can directly increase the level of cellular DNA damage. The occurrence of DNA damage led to cell cycle arrest and inhibition of cell metastasis and cell apoptosis. Mouse model experiments also confirmed that F1-7 could inhibit tumour growth by inhibiting the FGFR pathway.

CONCLUSIONS

F1-7 exhibits anti-tumour activity by inhibiting the FGFR pathway. It could be a novel therapeutic agent for targeting colon cancer cells.

Targeting autophagy in colorectal cancer: An update on pharmacological small-molecule compounds

Autophagy, an evolutionarily highly conserved cellular degradation process, plays the Janus role (either cytoprotective or death-promoting) in colorectal cancer, so the targeting of several key autophagic pathways with small-molecule compounds may be a new therapeutic strategy. In this review, we discuss autophagy-associated cell death pathways and key cytoprotective autophagy pathways in colorectal cancer. Moreover, we summarize a series of small-molecule compounds that have the potential to modulate autophagy-associated cell death or cytoprotective autophagy for therapeutic purposes. Taken together, these findings demonstrate the Janus role of autophagy in colorectal cancer, and shed new light on the exploitation of a growing number of small-molecule compounds to target autophagy in future cancer drug discovery.

Flubendazole induces mitochondrial dysfunction and DRP1-mediated mitophagy by targeting EVA1A in breast cancer

Breast cancer is still one of the most common malignancies worldwide and remains a major clinical challenge. We previously reported that the anthelmintic drug flubendazole induced autophagy and apoptosis via upregulation of eva-1 homolog A (EVA1A) in triple-negative breast cancer (TNBC) and was repurposed as a novel anti-tumor agent. However, the detailed underlying mechanisms remain unclear and need further investigation. Here, we found that flubendazole impairs the permeability of the mitochondrial outer membrane and mitochondrial function in breast cancer. Meanwhile, flubendazole increased dynamin-related protein (DRP1) expression, leading to the accumulation of PTEN induced putative kinase 1 (PINK1) and subsequent mitochondrial translocation of Parkin, thereby promoting excessive mitophagy. The resultant excessive mitophagy contributed to mitochondrial damage and dysfunction induced by flubendazole, thus inhibiting breast cancer cells proliferation and migration. Moreover, we demonstrated that excessive DRP1-mediated mitophagy played a critical role in response to the anti-tumor effects of EVA1A in breast cancer. Taken together, our results provide new insights into the molecular mechanisms in relation to the anti-tumor activities of flubendazole, and may be conducive to its rational use in potential clinical applications.

Double Repositioning: Veterinary Antiparasitic to Human Anticancer

Drug repositioning, the approach of discovering different uses for existing drugs, has gained enormous popularity in recent years in the anticancer drug discovery field due to the increasing demand for anticancer drugs. Additionally, the repurposing of veterinary antiparasitic drugs for the treatment of cancer is gaining traction, as supported by existing literature. A prominent example is the proposal to implement the use of veterinary antiparasitics such as benzimidazole carbamates and halogenated salicylanilides as novel anticancer drugs. These agents have revealed pronounced anti-tumor activities and gained special attention for “double repositioning”, as they are repurposed for different species and diseases simultaneously, acting via different mechanisms depending on their target. As anticancer agents, these compounds employ several mechanisms, including the inhibition of oncogenic signal transduction pathways of mitochondrial respiration and the inhibition of cellular stress responses. In this review, we summarize and provide valuable information about the experimental, preclinical, and clinical trials of veterinary antiparasitic drugs available for the treatment of various cancers in humans. This review suggests the possibility of new treatment options that could improve the quality of life and outcomes for cancer patients in comparison to the currently used treatments.

Benzimidazole-carbamate anthelmintics: Perspective candidates for the anticancer drug development

Cellular oncogenesis involves a complex interplay between the several synchronized, interdependent pathways that collectively determine the pathogenesis and pathophysiology of cancer. Limited therapeutic success with the existing anticancer drugs drew huge interest in the design and development of new pharmacophores with improved clinical efficacy, however despite huge investments in anticancer RD; the average number of Food and Drug Administration-approved anticancer drugs declined since the 1990s. The contemporary anticancer medications possess high attrition rates, bear substantial costs, and experience low efficacy owing to the drug resistance expressed by the aggressive tumors. Mainly, the translation of novel candidate anticancer drugs into clinical practice, their commercialization, and transformation from the bench to bedside require a long timeframe of 10-15 years and capital worth millions of dollars. The repurposing strategy substantially accelerated the anticancer drug development regime as the approved drugs with tested safety and efficacy ensure a minimal risk of failure, and nominal R&D expenses as anticipated for the newly identified candidate drugs yet to enter the clinical trials. In addition, the repurposed drugs ensure a rapid clinical translation due to a validated clinical profile and their ability to target the identified hallmarks and hitherto unknown vulnerabilities of cancer. The flagship project "Repurposing Drugs in Oncology" (ReDO) identified 268 "hard repurposing" noncancer medications as candidate drugs with a promising anticancer profile (https://www.anticancerfund.org/en/redo-db). However, the generic profile of 84% of repurposed drugs in ReDO data set discourages the commercial sponsors from funding the repurposing trials, especially the Phase III efficacy trials that require significant capital.

Hypocrellin A exerts antitumor effects by inhibiting the FGFR1 signaling pathway in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer, which is the deadliest form of cancer worldwide. Recent studies have shown that genes in the fibroblast growth factor (FGF) family are highly mutated in lung cancer, and fibroblast growth factor receptor 1 (FGFR1) has been found to be involved in various cancers, including lung cancer, suggesting that FGFR1 is a valid therapeutic target. Hypocrellin A (HA), a molecule with multiple biological activities, has been shown to influence cancer growth, but the specific mechanisms of its antitumor action have not been fully explored.

METHODS

MTT, colony formation, wound healing, transwell cell invasion and EdU cell proliferation assays were performed upon HA treatment of three NSCLC cell lines, H460, PC-9 and H1975. Hoechst 33258 staining and caspase 3 activity assays were carried out to investigate the impact of HA on apoptosis in these cells. Molecular docking and surface plasmon resonance were conducted to assess binding of HA to FGFR1. A mouse tumor model was used to detect the NSCLC-inhibitory ability of HA in vivo.

RESULTS

Through in vitro assays, HA was shown to negatively impact cell viability, migration, invasion and promote apoptosis in three human NSCLC cell line models. HA was shown to bind to FGFR1 and to inhibit its autophosphorylation and the phosphorylation of downstream signaling molecules. Inhibition of tumor growth was also demonstrated in a mouse xenograft tumor model, and no toxic effects of HA treatment were observed.

CONCLUSIONS

HA inhibits the activity of the FGFR1 and STAT3 signaling pathways. HA thus represents a potential new FGFR1-targeted treatment for NSCLC.

Flubendazole Plays an Important Anti-Tumor Role in Different Types of Cancers

Flubendazole, belonging to benzimidazole, is a broad-spectrum insect repellent and has been repurposed as a promising anticancer drug. In recent years, many studies have shown that flubendazole plays an anti-tumor role in different types of cancers, including breast cancer, melanoma, prostate cancer, colorectal cancer, and lung cancer. Although the anti-tumor mechanism of flubendazole has been studied, it has not been fully understood. In this review, we summarized the recent studies regarding the anti-tumor effects of flubendazole in different types of cancers and analyzed the related mechanisms, in order to provide the theoretical reference for further studies in the future.

Benzimidazoles induce concurrent apoptosis and pyroptosis of human glioblastoma cells via arresting cell cycle

Glioblastoma multiforme (GBM) is the most malignant and lethal primary brain tumor in adults accounting for about 50% of all gliomas. The only treatment available for GBM is the drug temozolomide, which unfortunately has frequent drug resistance issue. By analyzing the hub genes of GBM via weighted gene co-expression network analysis (WGCNA) of the cancer genome atlas (TCGA) dataset, and using the connectivity map (CMAP) platform for drug repurposing, we found that multiple azole compounds had potential anti-GBM activity. When their anti-GBM activity was examined, however, only three benzimidazole compounds, i.e. flubendazole, mebendazole and fenbendazole, potently and dose-dependently inhibited proliferation of U87 and U251 cells with IC₅₀ values below 0.26 μM. Benzimidazoles (0.125-0.5 μM) dose-dependently suppressed DNA synthesis, cell migration and invasion, and regulated the expression of key epithelial-mesenchymal transition (EMT) markers in U87 and U251 cells. Benzimidazoles treatment also dose-dependently induced the GBM cell cycle arrest at the G₂/M phase via the P53/P21/cyclin B1 pathway. Furthermore, the drugs triggered pyroptosis of GBM cells through the NF-κB/NLRP3/GSDMD pathway, and might also concurrently induced mitochondria-dependent apoptosis. In a nude mouse U87 cell xenograft model, administration of flubendazole (12.5, 25, and 50 mg · kg^-1 · d^-1, i.p, for 3 weeks) dose-dependently suppressed the tumor growth without obvious adverse effects. Taken together, our results demonstrated that benzimidazoles might be promising candidates for the treatment of GBM.

Cyclodextrin Dispersion of Mebendazole and Flubendazole Improves In Vitro Antiproliferative Activity

Mebendazole and flubendazole are antihelmintic drugs that have re-entered the research spotlight due to their exhibited anticancer effects, thus making them strong candidates as repurposed drugs. However, these benzimidazole derivatives exhibit poor solubility in water and various organic solvents, which limits their bioavailability. With the aim of obtaining an improved drug solubility and increased biological effect, mebendazole and flubendazole were complexed with 2-hydroxypropyl-β-cyclodextrin (HPBCD). The binary 1:1 conjugates were physicochemically evaluated by X-ray diffraction, thermal analysis, and FTIR spectroscopy, revealing the formation of physical mixtures. The increased aqueous solubility of the binary 1:1 conjugates vs. pure benzimidazole compounds was demonstrated by performing dissolution tests. The in vitro antiproliferative activity of mebendazole and flubendazole, as well as their combination with HPBCD, was tested on two cancer cell lines, human melanoma—A375 and pulmonary adenocarcinoma—A549 by the MTT assay. The cytotoxic activity manifested in a dose-dependent manner while the presence of HPBCD increased the antiproliferative activity against the targeted cells. Treatment of A375 and A549 cell lines with the binary conjugates induced a significant inhibition of mitochondrial respiration, as revealed by high-resolution respirometry studies. Molecular docking analysis showed that one of the mechanisms related to MEB and FLU cytotoxic activity may be due to the inhibition of MEK/ERK proteins.

Emerging insights on functions of the anthelmintic flubendazole as a repurposed anticancer agent

While flubendazole has been used as a macrofilaricide in humans and animals for some 40 years, work in vitro and in preclinical models over the last decade has suggested its potential use as an anticancer agent. This article reviews recent studies in a range of tumor types indicating novel functions for flubendazole in its control of processes associated with tumor growth, spread and renewal including ferroptosis, autophagy, cancer stem-like cell killing and suppression of intratumoral myeloid-derived suppressor cell accumulation and programmed cell death protein 1. Flubendazole's potential use in clinical oncology will require further understanding of its mechanistic roles, range of inhibition of cancer types, capacity for adjunctive therapy and possible reformulation for enhanced solubility, bioavailability and potency.

Repurposing drugs in autophagy for the treatment of cancer: From bench to bedside

Autophagy is a multistep degradation pathway involving the lysosome, which supports nutrient reuse and metabolic balance, and has been implicated as a process that regulates cancer genesis and development. Targeting tumors by regulating autophagy has become a therapeutic strategy of interest. Drugs with other indications can have antitumor activity by modulating autophagy, providing a shortcut to developing novel antitumor drugs (i.e., drug repurposing/repositioning), as successfully performed for chloroquine (CQ); an increasing number of repurposed drugs have since advanced into clinical trials. In this review, we describe the application of different drug-repurposing approaches in autophagy for the treatment of cancer and focus on repurposing drugs that target autophagy to treat malignant neoplasms.

PD-L1 Status in Gastric Cancers, Association with the Transcriptional, Growth Factors, AKT/mTOR Components Change, and Autophagy Initiation

Introduction: The programmed death receptor ligand 1 (PD-L1) immunohistochemistry (IHC) assay is a widely used selection method for pembrolizumab treatment in gastric cancer (GC) patients. PD-L1 is the main regulator of immunity in oncogenesis. Material and methods: The study included 38 patients with GC. The combined treatment consisted of neoadjuvant FOLFOX6, or FLOT, chemotherapy and surgery. PD-L1 + tumor status was recorded in 12 patients (CPS > 5), with a negative status recorded in 26 patients. RT-PCR determined the expression of molecular markers. The level of LC3B protein was detected by Western Blotting analysis. Results: An overexpression of PD-1, PD-L2 in the tumor is associated with AKT/mTOR mRNA profile change and autophagy initiation in IHC PD-L1 positive GCs. NACT influences these biological features, modifying the expression of AKT/mTOR components and autophagic flux. In PD-L1 positive cancers, the effect of NACT and molecular markers rearrangements are essential compared to the PD-L1 negative cancers. Conclusion: The IHC PD-L1 status in gastric cancers is the significant marker of cancer progression, recovering the multiple inner mechanisms of cancer spreading and leading to ineffective therapy. Autophagy induction and angiogenesis are found in PD-L1 positive gastric cancers.

Cyy260, a novel small molecule inhibitor, suppresses non-small cell lung cancer cell growth via JAK2/STAT3 pathway

Non-small cell lung cancer (NSCLC) is a malignant tumor that accounts for the most new cancer cases and cancer-related deaths worldwide, and the proliferation and metastasis of NSCLC are the main reasons for treatment failure and patient death. Traditional chemotherapeutic drugs have low selectivity, which can kill cancer cells and cause damage to normal cells at the same time. Therefore, it is particularly important to study therapies that target cancer cells and to find low-toxicity, high-efficiency anticancer drugs. Cyy260 is a novel small molecule inhibitor that we synthesized for the first time. Here, we investigated the in vitro and in vivo antitumor activities of Cyy260 and explored the underlying mechanisms in NSCLC. Cyy260 had a concentration- and time-dependent inhibitory effect on NSCLC cells, but it was less toxic to normal cells. Cyy260 regulated apoptosis through intracellular and extracellular apoptotic pathways. In addition, Cyy260 could also induce cell cycle arrest, thereby inhibiting cell proliferation. Further analysis of molecular mechanisms showed that the JAK2/STAT3 signaling pathway was involved in the antitumor effect mediated by Cyy260. Analysis of subcutaneously transplanted tumors in mice showed that Cyy260 suppressed tumor growth in vivo. Our results proved that Cyy260 is a novel inhibitor of the JAK2/STAT3 pathway thus may have potential in therapy of NSCLC and other cancers.

Flubendazole Elicits Antitumor Effects by Inhibiting STAT3 and Activating Autophagy in Non-small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) is a major neoplastic disease with a high mortality worldwide; however, effective treatment of this disease remains a challenge. Flubendazole, a traditional anthelmintic drug, possesses potent antitumor properties; however, the detailed molecular mechanism of flubendazole activity in NSCLC needs to be further explored. In the present study, flubendazole was found to exhibit valid antitumor activity in vitro as well as in vivo. Flubendazole blocked phosphorylation of STAT3 in a dose- and time-dependent manner and regulated the transcription of STAT3 target genes encoding apoptotic proteins. Further, flubendazole inhibited STAT3 activation by inhibiting its phosphorylation and nuclear localization induced by interleukin-6 (IL-6). Notably, the autophagic flux of NSCLC cell lines was increased after flubendazole treatment. Furthermore, flubendazole downregulated the expression of BCL2, P62, and phosphorylated-mTOR, but it upregulated LC3-I/II and Beclin-1 expression, which are the main genes associated with autophagy. Collectively, these data contribute to elucidating the efficacy of flubendazole as an anticancer drug, demonstrating its potential as a therapeutic agent via its suppression of STAT3 activity and the activation of autophagy in NSCLC.

Progress in Redirecting Antiparasitic Drugs for Cancer Treatment

Drug repurposing is a feasible strategy in developing novel medications. Regarding the cancer field, scientists are continuously making efforts to redirect conventional drugs into cancer treatment. This approach aims at exploring new applications in the existing agents. Antiparasitic medications, including artemisinin derivatives (ARTs), quinine-related compounds, niclosamide, ivermectin, albendazole derivatives, nitazoxanide and pyrimethamine, have been deeply investigated and widely applied in treating various parasitic diseases for a long time. Generally, their pharmacokinetic and pharmacodynamic properties are well understood, while the side effects are roughly acceptable. Scientists noticed that some of these agents have anticancer potentials and explored the underlying mechanisms to achieve drug repurposing. Recent studies show that these agents inhibit cancer progression via multiple interesting ways, inducing ferroptosis induction, autophagy regulation, mitochondrial disturbance, immunoregulation, and metabolic disruption. In this review, we summarize the recent advancement in uncovering antiparasitic drugs' anticancer properties from the perspective of their pharmacological targets. Instead of paying attention to the previously discovered mechanisms, we focus more on newly emerging ones that are worth noticing. While most investigations are focusing on the mechanisms of their antiparasitic effect, more in vivo exploration in clinical trials in the future is necessary. Moreover, we also paid attention to what limits the clinical application of these agents. For some of these agents like ARTs and niclosamide, drug modification, novel delivery system invention, or drug combination are strongly recommended for future exploration.

Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signalling

BACKGROUND

Diverse signalling pathways are involved in carcinogenesis and one of such pathways implicated in many cancers is the interleukin 6/signal transducer and activator of transcription 3 (IL-6/STAT3) signalling pathway. Therefore, inhibition of this pathway is targeted as an anti-cancer intervention. This study aimed to establish the effect of cryptolepine, which is the main bioactive alkaloid in the medicinal plant Cryptolepis sanguinolenta, on the IL-6/STAT3 signalling pathway.

METHODS

First, the effect of cryptolepine on the IL-6/STAT3 pathway in human hepatoma cells (HepG2 cells) was screened using the Cignal Finder Multi-Pathway Reporter Array. Next, to confirm the effect of cryptolepine on the IL-6/STAT3 signalling pathway, the pathway was activated using 200 ng/mL IL-6 in the presence of 0.5-2 μM cryptolepine. The levels of total STAT3, p-STAT3 and IL-23 were assessed by ELISA.

RESULTS

Cryptolepine downregulated 12 signalling pathways including the IL-6/STAT3 signalling pathway and upregulated 17 signalling pathways. Cryptolepine, in the presence of IL-6, decreased the levels of p-STAT3 and IL-23 in a dose-dependent fashion.

CONCLUSION

Our results demonstrated that cryptolepine inhibits the IL-6/STAT3 signalling pathway, and therefore cryptolepine-based remedies such as Cryptolepis sanguinolenta could potentially be used as an effective immunotherapeutic agent for hepatocellular carcinoma and other cancers.

Drug Repurposing in Oncology: Current Evidence and Future Direction

BACKGROUND

Drug repurposing, the application of known drugs and compounds with a primary non-oncology purpose, might be an attractive strategy to offer more effective treatment options to cancer patients at a low cost and reduced time.

METHODS

This review described a total of 10 kinds of non-oncological drugs from more than 100 mechanical studies as well as evidence from population-based studies. The future direction of repurposed drug screening is discussed by using patient-derived tumor organoids.

RESULTS

Many old drugs showed previously unknown effects or off-target effects and can be intelligently applied for cancer chemoprevention and therapy. The identification of repurposed drugs needs to combine evidence from mechanical studies and population-based studies. Due to the heterogeneity of cancer, patient-derived tumor organoids can be used to screen the non-oncological drugs in vitro.

CONCLUSION

These identified old drugs could be repurposed in oncology and might be added as adjuvants and finally benefit patients with cancers.

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.

The Effects of Autophagy-Related Genes and lncRNAs in Therapy and Prognosis of Colorectal Cancer

Cellular autophagy plays an important role in the occurrence and development of colorectal cancer (CRC). Whether autophagy-related genes and lncRNAs can be used as ideal markers in CRC is still controversial. The purpose of this study is to identify novel treatment and prognosis markers of CRC. We downloaded transcription and clinical data of CRC from the GEO (GSE40967, GSE12954, GSE17536) and TCGA database, screened for differentially autophagy-related genes (DEAGs) and lncRNAs, constructed prognostic model, and analyzed its relationship with immune infiltration. TCGA and GEO datasets (GSE12954 and GSE17536) were used to validate the effect of the model. Oncomine database and Human Protein Atlas verified the expression of DEAGs. We obtained a total of 151 DEAGs in three verification sets collaboratively. Then we constructed a risk prognostic model through Lasso regression to obtain 15 prognostic DEAGs from the training set and verified the risk prognostic model in three verification sets. The low-risk group survived longer than the high-risk group. Age, gender, pathological stage, and TNM stage were related to the prognostic risk of CRC. On the other hand, BRAF status, RFS event, and tumor location are considered as most significant risk factors of CRC in the training set. Furthermore, we found that the immune score of the low-risk group was higher. The content of CD8 + T cells, active NK cells, macrophages M0, macrophages M1, and active dendritic cells was noted more in the high-risk group. The content of plasma cells, resting memory CD4 + T cells, resting NK cells, resting mast cells, and neutrophil cells was higher in the low-risk group. After all, the Oncomine database and immunohistochemistry verified that the expression level of most key autophagy-related genes was consistent with the results that we found. In addition, we obtained six lncRNAs co-expressed with DEAGs from the training set and found that the survival time was longer in the low-risk group. This finding was verified in the verification set and showed same trend to the results mentioned above. In the final analysis, these results indicate that autophagy-related genes and lncRNAs can be used as prognostic and therapeutic markers for CRC.

[Flubendazole Inhibits the Proliferation of A549 and H460 Cells and Promotes Autophagy]

背景与目的

氟苯达唑是一种苯并咪唑类驱虫药, 既往研究发现其对结肠癌、乳腺癌细胞增殖具有抑制作用。本研究旨在探讨氟苯达唑对非小细胞肺癌A549、H460细胞增殖的影响及机制。

方法

通过CCK-8(Cell Counting Kit-8)法检测不同浓度的氟苯达唑对A549、H460细胞活力的影响; Western blot法检测氟苯达唑处理后细胞自噬相关蛋白p62、LC3的表达水平; 自噬双标腺病毒(mRFP-GFP-LC3)转染细胞, 分析细胞内自噬流变化。

结果

氟苯达唑抑制A549、H460细胞增殖, 并呈剂量依赖关系(P < 0.001)。2 μmol/L氟苯达唑处理A549、H460细胞24 h、48 h后p62减少, LC3 II/I比值升高(P < 0.005)。mRFP-GFP-LC3转染细胞显示氟苯达唑处理组红色荧光增加, 提示自噬流增强。

结论

氟苯达唑可以抑制A549、H460细胞增殖并促进自噬。

Flubendazole, FDA-approved anthelmintic, elicits valid antitumor effects by targeting P53 and promoting ferroptosis in castration-resistant prostate cancer

On account of incurable castration-resistant prostate cancer (CRPC) inevitably developing after treating with androgen deprivation therapy, it is an urgent need to find new therapeutic strategies. Flubendazole is a well-known anti-malarial drug that is recently reported to be a potential anti-tumor agent in various types of human cancer cells. However, whether flubendazole could inhibit the castration-resistant prostate cancer has not been well charified. Thus, the aim of the present study was to characterize the precise mechanism of action of flubendazole on the CRPC. In this study, we investigated the potential effect of flubendazole on cell proliferation, cell cycle and cell death in CRPC cells (PC3 and DU145). We found that flubendazole inhibited cell proliferation, caused cell cycle arrest in G2/M phase and promoted cell death in vitro, and suppressed growth of CRPC tumor in xenograft models. In addition, we reported that flubendazole induced the expression of P53, which partly accounted for the G2/M phase arrest and led to inhibition of the transcription of SLC7A11, and then downregulated the GPX4, which is a major ferroptosis-related gene. Furthermore, flubendazole exhibited synergistic effect with 5-fluorouracil (5-Fu) in chemotherapy of CRPC. This study provides biological evidence that flubendazole is a novel P53 inducer which exerts anti-proliferation and pro-apoptosis effects in CRPC through hindering the cell cycle and activating the ferroptosis, and indicates that a novel utilization of flubendazole in neoadjuvant chemotherapy of CRPC.

Cinobufagin suppresses colorectal cancer growth via STAT3 pathway inhibition

Colorectal cancer (CRC) has become one of the most common types of cancer with the highest morbidity and mortality rates globally. Cinobufagin, a natural product extracted from toad venom and a major active ingredient in cinobufotalin, exhibits high antitumor activity. Here, we investigated the in vitro and in vivo antitumor activities of cinobufagin and explored the underlying mechanisms in CRC. Cinobufagin could inhibit proliferation, migration, invasion and promote apoptosis of HCT116, RKO, and SW480 cells in vitro. Mechanistically, cinobufagin simultaneously suppressed the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and blocked the interleukin-6 (IL6)-induced nuclear translocation of STAT3. IL6 activated the STAT3 pathway, subsequently inducing epithelial-mesenchymal transition (EMT). Furthermore, cinobufagin suppressed EMT in CRC by inhibiting the STAT3 pathway. Animal experiments clearly showed that cinobufagin could reduce tumor growth. Cinobufagin may be used clinically as a novel STAT3 inhibitor for CRC adjuvant therapy.

Gracillin shows potent efficacy against colorectal cancer through inhibiting the STAT3 pathway

Colorectal cancer (CRC) accounts for about 10% of all annually diagnosed cancers and cancer-related deaths worldwide. STAT3 plays a vital role in the occurrence and development of tumours. Gracillin has shown a significant antitumour activity in tumours, but its mechanism remains unknown. The human CRC cell lines HCT116, RKO, and SW480 and immunodeficient mice were used as models to study the effects of gracillin on cell proliferation, migration and apoptosis. These were evaluated by cell viability, colony formation, wound-healing migration and cell apoptosis assays. Luciferase reporter assay, and immunostaining and western blot analyses were used to explore the specific mechanism through which gracillin exerts its effects. Gracillin significantly reduces viability and migration and stimulates apoptosis in human CRC cells. It also significantly inhibits tumour growth with no apparent physiological toxicity in animal model experiments. Moreover, gracillin is found to inhibit STAT3 phosphorylation and STAT3 target gene products. In addition, gracillin inhibits IL6-induced nuclear translocation of P-STAT3. Gracillin shows potent efficacy against CRC by inhibiting the STAT3 pathway. It should be further explored as a unique STAT3 inhibitor for the treatment of CRC.

Potential and mechanism of mebendazole for treatment and maintenance of ovarian cancer

OBJECTIVE

Mebendazole and other anti-parasitic drugs are being used off-prescription based on social media and unofficial accounts of their anti-cancer activity. The purpose of this study was to conduct a controlled evaluation of mebendazole's therapeutic efficacy in cell culture and in vivo models of ovarian cancer. The majority of ovarian cancers harbor p53 null or missense mutations, therefore the effects of p53 mutations and a mutant p53 reactivator, PRIMA-1^MET (APR246) on mebendazole activity were evaluated.

METHODS

Mebendazole was evaluated in cisplatin-resistant high grade serous stage 3C ovarian cancer patient derived xenograft (PDX) models: PDX-0003 (p53 null) and PDX-0030 (p53 positive), and on ovarian cancer cell lines: MES-OV (p53 R282W), ES2 (p53 S241F), A2780 (p53 wild type), SKOV3 parental (p53 null) and isogenic sublines, SKOV3 R273H p53 and SKOV3 R248W p53. Drug synergy and mechanisms were evaluated in cell cultures using isobolograms, clonogenic assays and western blots. Prevention of tumor establishment was studied in a MES-OV orthotopic model.

RESULTS

Mebendazole inhibited growth of ovarian cancer cell cultures at nanomolar concentrations and PDXs at doses up to 50 mg/kg, and reduced orthotopic tumor establishment at 50 mg/kg. The mechanism of mebendazole was associated with p53-independent induction of p21 and tubule depolymerization. PRIMA-1^MET also inhibited tumor establishment and worked synergistically with mebendazole in cell culture to inhibit growth and induce intrinsic apoptosis through a p53- and tubule destabilization-independent mechanism.

CONCLUSION

This work demonstrates the therapeutic potential of repurposing mebendazole and supports clinical development of mebendazole for ovarian cancer therapy and maintenance.

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.