Clinically relevant concentration of anti-viral drug ribavirin selectively targets pediatric osteosarcoma and increases chemosensitivity

Effect of anti-COVID-19 drugs on patients with cancer

The clinical treatment of patients with cancer who are also diagnosed with coronavirus disease (COVID-19) has been a challenging issue since the outbreak of COVID-19. Therefore, it is crucial to understand the effects of commonly used drugs for treating COVID-19 in patients with cancer. Hence, this review aims to provide a reference for the clinical treatment of patients with cancer to minimize the losses caused by the COVID-19 pandemic. In this study, we also focused on the relationship between COVID-19, commonly used drugs for treating COVID-19, and cancer. We specifically investigated the effect of these drugs on tumor cell proliferation, migration, invasion, and apoptosis. The potential mechanisms of action of these drugs were discussed and evaluated. We found that most of these drugs showed inhibitory effects on tumors, and only in a few cases had cancer-promoting effects. Furthermore, inappropriate usage of these drugs may lead to irreversible kidney and heart damage. Finally, we have clarified the use of different drugs, which can provide useful guidance for the clinical treatment of cancer patients diagnosed with COVID-19.

Inhibition of Macropinocytosis Enhances the Sensitivity of Osteosarcoma Cells to Benzethonium Chloride

Osteosarcoma (OS) is a primary malignant tumor of bone. Chemotherapy is one of the crucial approaches to prevent its metastasis and improve prognosis. Despite continuous improvements in the clinical treatment of OS, tumor resistance and metastasis remain dominant clinical challenges. Macropinocytosis, a form of non-selective nutrient endocytosis, has received increasing attention as a novel target for cancer therapy, yet its role in OS cells remains obscure. Benzethonium chloride (BZN) is an FDA-approved antiseptic and bactericide with broad-spectrum anticancer effects. Here, we described that BZN suppressed the proliferation, migration, and invasion of OS cells in vitro and in vivo, but simultaneously promoted the massive accumulation of cytoplasmic vacuoles as well. Mechanistically, BZN repressed the ERK1/2 signaling pathway, and the ERK1/2 activator partially neutralized the inhibitory effect of BZN on OS cells. Subsequently, we demonstrated that vacuoles originated from macropinocytosis and indicated that OS cells might employ macropinocytosis as a compensatory survival mechanism in response to BZN. Remarkably, macropinocytosis inhibitors enhanced the anti-OS effect of BZN in vitro and in vivo. In conclusion, our results suggest that BZN may inhibit OS cells by repressing the ERK1/2 signaling pathway and propose a potential strategy to enhance the BZN-induced inhibitory effect by suppressing macropinocytosis.

Synthetic 1,2,4-triazole-3-carboxamides Induce Cell Cycle Arrest and Apoptosis in Leukemia Cells

BACKGROUND

A number of studies demonstrate the efficacy of ribavirin against various cancer types in in vitro and in vivo models. However, ribavirin induces the development of multiple side effects, suggesting a high demand for ribavirin analogues with improved therapeutic indexes.

OBJECTIVE

This study was focused on the analysis of ribavirin, its aglycon 1,2,4-triazole-3-carboxamide, and several of its derivatives activities in blood cancer cells in vitro.

METHODS

Four 1,2,4-triazole-3-carboxamide derivatives were designed and synthesized. Antiproliferative effects were evaluated in chronic myeloid leukemia cells К562 and acute lymphoblastic leukemia cells CCRF-SB as well as in the cells of whole blood mononuclear fraction of healthy volunteers by cell counting using the trypan blue exclusion method. Cell cycle distribution and apoptosis under the influence of the compounds were analyzed by flow cytometry with PI staining, and then apoptosis data were confirmed by Western blot analysis for PARP1 and caspase-3 cleavage.

RESULTS

We demonstrated the significant antiproliferative effect of 5-(tetrahydropyran-2-yl)-1,2,4-triazole-3- carboxamide and 1-(tetrahydropyran-2-yl)-1,2,4-triazol-3-carboxamide in leukemia cell lines in vitro in comparison to non-transformed monocytes, providing the rationale for further studies of 1,2,4-triazole-3-carboxamide derivatives as anti-leukemia drugs.

CONCLUSION

These results implied that the 1,2,4-triazole-3-carboxamide derivatives exhibited their antiproliferative activities by induction of cell cycle arrest. Consequently, 5-(tetrahydropyran-2-yl)-1,2,4-triazole-3-carboxamide and 1-(tetrahydrofuran-2-yl)-1,2,4-triazol-3-carboxamide may present antimetabolites with potential anticancer efficacy.

MAPK-interacting kinases inhibition by eFT508 overcomes chemoresistance in preclinical model of osteosarcoma

The MAPK-interacting kinases 1 and 2 (MNK1/2) have generated increasing interest as therapeutic targets for many cancers with little known in osteosarcoma. This study evaluated the efficacy of eFT508, a highly selective inhibitor of MNK1/2, as single drug alone and in combination with paclitaxel in preclinical models of osteosarcoma. EFT508 is active against multiple osteosarcoma cell lines via inhibiting growth, survival and migration. It also demonstrates anti-osteosarcoma selectivity with much less toxicity on normal osteoblastic than osteosarcoma cells. Consistent with in vitro findings, eFT508 at non-toxic dose significantly arrested tumor growth in mice throughout the whole duration of treatment. Mechanistically, eEFT508 is highly effective in blocking eIF4E phosphorylation and eIF4E-mediated protein translation. Combination index shows that eFT508 and paclitaxel is synergistic in osteosarcoma cells. Our findings highlight the therapeutic value of MNK1/2 inhibition and suggest eFT508 as a promising candidate for the treatment of osteosarcoma.

Cerebral Organoids for Modeling of HSV-1-Induced-Amyloid β Associated Neuropathology and Phenotypic Rescue

Herpes simplex virus type I (HSV-1) infection is a potential risk factor involved in the Amyloid β (Aβ) associated neuropathology. However, further understanding of the neuropathological effects of the HSV-1 infection is hampered by the limitations of existing infection models due to the distinct differences between human brains and other mammalians’ brains. Here we generated cerebral organoid models derived from pluripotent stem cells to investigate the HSV-induced Aβ associated neuropathology and the role of antiviral drugs in the phenotypic rescue. Our results identified that the HSV-1-infected cerebral organoids recapitulated Aβ associated neuropathology including the multicellular Aβ deposition, dysregulated endogenous AD mediators, reactive gliosis, neuroinflammation, and neural loss, indicating that cerebral organoids offer an opportunity for modeling the interaction of HSV-1 with the complex phenotypes across the genetic, cellular, and tissue levels of the human Alzheimer’s disease (AD). Furthermore, we identified that two antiviral drugs, namely Ribavirin (RBV) and Valacyclovir (VCV), inhibited HSV-1 replication and rescued the neuropathological phenotypes associated with AD in the HSV-1-infected cerebral organoids, implying their therapeutic potential to slow down the progression of AD. Our study provides a high-fidelity human-relevant in-vitro HSV-1 infection model to reconstitute the multiscale neuropathological features associated with AD and discover therapeutic drug candidates relevant to the AD viral hypothesis.

A Review: PI3K/AKT/mTOR Signaling Pathway and Its Regulated Eukaryotic Translation Initiation Factors May Be a Potential Therapeutic Target in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor developing from the esophageal squamous epithelium, and is the most common histological subtype of esophageal cancer (EC). EC ranks 10th in morbidity and sixth in mortality worldwide. The morbidity and mortality rates in China are both higher than the world average. Current treatments of ESCC are surgical treatment, radiotherapy, and chemotherapy. Neoadjuvant chemoradiotherapy plus surgical resection is recommended for advanced patients. However, it does not work in the significant promotion of overall survival (OS) after such therapy. Research on targeted therapy in ESCC mainly focus on EGFR and PD-1, but neither of the targeted drugs can significantly improve the 3-year and 5-year survival rates of disease. Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is an important survival pathway in tumor cells, associated with its aggressive growth and malignant progression. Specifically, proliferation, apoptosis, autophagy, and so on. Related genetic alterations of this pathway have been investigated in ESCC, such as PI3K, AKT and mTOR-rpS6K. Therefore, the PI3K/AKT/mTOR pathway seems to have the capability to serve as research hotspot in the future. Currently, various inhibitors are being tested in cells, animals, and clinical trials, which targeting at different parts of this pathway. In this work, we reviewed the research progress on the PI3K/AKT/mTOR pathway how to influence biological behaviors in ESCC, and discussed the interaction between signals downstream of this pathway, especially eukaryotic translation initiation factors (eIFs) and the development and progression of ESCC, to provide reference for the identification of new therapeutic targets in ESCC.

Repurposing of Antimicrobial Agents for Cancer Therapy: What Do We Know?

The substantial costs of clinical trials, the lengthy timelines of new drug discovery and development, along the high attrition rates underscore the need for alternative strategies for finding quickly suitable therapeutics agents. Given that most approved drugs possess more than one target tightly linked to other diseases, it encourages promptly testing these drugs in patients. Over the past decades, this has led to considerable attention for drug repurposing, which relies on identifying new uses for approved or investigational drugs outside the scope of the original medical indication. The known safety of approved drugs minimizes the possibility of failure for adverse toxicology, making them attractive de-risked compounds for new applications with potentially lower overall development costs and shorter development timelines. This latter case is an exciting opportunity, specifically in oncology, due to increased resistance towards the current therapies. Indeed, a large body of evidence shows that a wealth of non-cancer drugs has beneficial effects against cancer. Interestingly, 335 drugs are currently being evaluated in different clinical trials for their potential activities against various cancers (Redo database). This review aims to provide an extensive discussion about the anti-cancer activities exerted by antimicrobial agents and presents information about their mechanism(s) of action and stage of development/evaluation.

Inhibitors of Eukaryotic Translational Machinery as Therapeutic Agents

Inhibiting eukaryotic protein translation with small molecules is emerging as a powerful therapeutic strategy. The advantage of targeting cellular translational machinery is that it is required for the highly proliferative state of many neoplastic cells, replication of certain viruses, and ultimately the expression of a wide variety of protein targets. Although, this approach has been exploited to develop clinical agents, such as homoharringtonine (HHT, 1), used to treat chronic myeloid leukemia (CML), inhibiting components of the translational machinery is often associated with cytotoxic phenotypes. However, recent studies have demonstrated that certain small molecules can inhibit the translation of specific subsets of proteins, leading to lower cytotoxicity, and opening-up therapeutic opportunities for translation inhibitors to be deployed in indications beyond oncology and infectious disease. This review summarizes efforts to develop inhibitors of the eukaryotic translational machinery as therapeutic agents and highlights emerging opportunities for translation inhibitors in the future.

Epidrug Repurposing: Discovering New Faces of Old Acquaintances in Cancer Therapy

Gene mutations are strongly associated with tumor progression and are well known in cancer development. However, recently discovered epigenetic alterations have shown the potential to greatly influence tumoral response to therapy regimens. Such epigenetic alterations have proven to be dynamic, and thus could be restored. Due to their reversible nature, the promising opportunity to improve chemotherapy response using epigenetic therapy has arisen. Beyond helping to understand the biology of the disease, the use of modern clinical epigenetics is being incorporated into the management of the cancer patient. Potential epidrug candidates can be found through a process known as drug repositioning or repurposing, a promising strategy for the discovery of novel potential targets in already approved drugs. At present, novel epidrug candidates have been identified in preclinical studies and some others are currently being tested in clinical trials, ready to be repositioned. This epidrug repurposing could circumvent the classic paradigm where the main focus is the development of agents with one indication only, while giving patients lower cost therapies and a novel precision medical approach to optimize treatment efficacy and reduce toxicity. This review focuses on the main approved epidrugs, and their druggable targets, that are currently being used in cancer therapy. Also, we highlight the importance of epidrug repurposing by the rediscovery of known chemical entities that may enhance epigenetic therapy in cancer, contributing to the development of precision medicine in oncology.

Repurposing Old Drugs into New Epigenetic Inhibitors: Promising Candidates for Cancer Treatment?

Epigenetic alterations, as a cancer hallmark, are associated with cancer initiation, progression and aggressiveness. Considering, however, that these alterations are reversible, drugs that target epigenetic machinery may have an inhibitory effect upon cancer treatment. The traditional drug discovery pathway is time-consuming and expensive, and thus, new and more effective strategies are required. Drug Repurposing (DR) comprises the discovery of a new medical indication for a drug that is approved for another indication, which has been recalled, that was not accepted or failed to prove efficacy. DR presents several advantages, mainly reduced resources, absence of the initial target discovery process and the reduced time necessary for the drug to be commercially available. There are numerous old drugs that are under study as repurposed epigenetic inhibitors which have demonstrated promising results in in vitro tumor models. Herein, we summarize the DR process and explore several repurposed drugs with different epigenetic targets that constitute promising candidates for cancer treatment, highlighting their mechanisms of action.

Critical View on the Usage of Ribavirin in Already Existing Psychostimulant-Use Disorder

Substance-use disorder represents a frequently hidden non-communicable chronic disease. Patients with intravenous drug addiction are at high risk of direct exposure to a variety of viral infections and are considered to be the largest subpopulation infected with the hepatitis C virus. Ribavirin is a synthetic nucleoside analog that has been used as an integral component of hepatitis C therapy. However, ribavirin medication is quite often associated with pronounced psychiatric adverse effects. It is not well understood to what extent ribavirin per se contributes to changes in drug-related neurobehavioral disturbances, especially in the case of psychostimulant drugs, such as amphetamine. It is now well-known that repeated amphetamine usage produces psychosis in humans and behavioral sensitization in animals. On the other hand, ribavirin has an affinity for adenosine A1 receptors that antagonistically modulate the activity of dopamine D1 receptors, which play a critical role in the development of behavioral sensitization. This review will focus on the current knowledge of neurochemical/ neurobiological changes that exist in the psychostimulant drug-addicted brain itself and the antipsychotic-like efficiency of adenosine agonists. Particular attention will be paid to the potential side effects of ribavirin therapy, and the opportunities and challenges related to its application in already existing psychostimulant-use disorder.

Inhibition of mitochondrial translation selectively targets osteosarcoma

The unique dependence of cancer cells on mitochondrial metabolism has been exploited therapeutically in various cancers but not osteosarcoma. In this work, we demonstrate that inhibition of mitochondrial translation is effective and selective in targeting osteosarcoma. We firstly showed that tigecycline at pharmacological achievable concentrations inhibited growth and induced apoptosis of multiple osteosarcoma cell lines while sparing normal osteoblast cells. Similarly, tigecycline at effective doses that delayed osteosarcoma growth did not cause significant toxicity to mice. We next showed that tigecycline specifically inhibits mitochondrial translation, resulting in defective mitochondrial respiration in both osteosarcoma and normal osteoblast cells. We further confirm mitochondrial respiration as the target of tigecycline using three independent approaches. In addition, we demonstrate that compared to normal osteoblasts, osteosarcoma cells have higher mitochondrial biogenesis. We finally show that specific inhibition of mitochondrial translation via EF-Tu depletion produces the similar anti-osteosarcoma effects of tigecycline. Our work highlights the therapeutic value of targeting mitochondrial metabolism in osteosarcoma and tigecycline as a useful addition to the treatment of osteosarcoma.