Cimetidine repurposed as a potential immunomodulatory agent against colorectal carcinoma: A systematic review

OBJECTIVE

To determine the survival benefit and immunomodulatory effects of cimetidine pre-, peri- or post-operatively in patients with colorectal cancer (CRC).

METHODS

A systematic review was conducted using PubMed and Cochrane Library to retrieve randomized control trials (RCTs) that investigated the effects of cimetidine on survival and immunomodulation via improvement in tumor infiltrating lymphocytes (TILs) and peripheral blood lymphocytes. The review was carried out in accordance with the extended Preferred Reporting Items for Systematic Reviews and Meta-analyses.

RESULTS

Four studies with the total of 267 patients were included in this systematic review. Treatment duration varied from 5 days to 1 year. Two studies reported a significant TIL response in the resected specimens after administering cimetidine, while one RCT showed an escalation of CD3, CD4 and CD57 lymphocytes in peripheral blood compared to the baseline following cimetidine treatment (p < 0.01). Of the three trials that examined the effects of cimetidine on survival, only two studies revealed significant survival benefit while the remaining study only showed a trend towards survival benefit.

CONCLUSION

Repurposing of existing drugs like cimetidine has a potential to offer a survival benefit by acting as an immunomodulatory agent in patients undergoing curative resection for CRC. However, the heterogeneity seen in current studies and the evolvement of adjunctive therapies for CRC warrant large-scale, well-designed prospective RCTs to establish the efficacy of cimetidine in CRC.

Evaluation of bumetanide as a potential therapeutic agent for Alzheimer's disease

Therapeutics discovery and development for Alzheimer's disease (AD) has been an area of intense research to alleviate memory loss and the underlying pathogenic processes. Recent drug discovery approaches have utilized in silico computational strategies for drug candidate selection which has opened the door to repurposing drugs for AD. Computational analysis of gene expression signatures of patients stratified by the APOE4 risk allele of AD led to the discovery of the FDA-approved drug bumetanide as a top candidate agent that reverses APOE4 transcriptomic brain signatures and improves memory deficits in APOE4 animal models of AD. Bumetanide is a loop diuretic which inhibits the kidney Na+-K+-2Cl- cotransporter isoform, NKCC2, for the treatment of hypertension and edema in cardiovascular, liver, and renal disease. Electronic health record data revealed that patients exposed to bumetanide have lower incidences of AD by 35%-70%. In the brain, bumetanide has been proposed to antagonize the NKCC1 isoform which mediates cellular uptake of chloride ions. Blocking neuronal NKCC1 leads to a decrease in intracellular chloride and thus promotes GABAergic receptor mediated hyperpolarization, which may ameliorate disease conditions associated with GABAergic-mediated depolarization. NKCC1 is expressed in neurons and in all brain cells including glia (oligodendrocytes, microglia, and astrocytes) and the vasculature. In consideration of bumetanide as a repurposed drug for AD, this review evaluates its pharmaceutical properties with respect to its estimated brain levels across doses that can improve neurologic disease deficits of animal models to distinguish between NKCC1 and non-NKCC1 mechanisms. The available data indicate that bumetanide efficacy may occur at brain drug levels that are below those required for inhibition of the NKCC1 transporter which implicates non-NKCC1 brain mechansims for improvement of brain dysfunctions and memory deficits. Alternatively, peripheral bumetanide mechanisms may involve cells outside the central nervous system (e.g., in epithelia and the immune system). Clinical bumetanide doses for improved neurological deficits are reviewed. Regardless of mechanism, the efficacy of bumetanide to improve memory deficits in the APOE4 model of AD and its potential to reduce the incidence of AD provide support for clinical investigation of bumetanide as a repurposed AD therapeutic agent.

Innovative, rapid, high-throughput method for drug repurposing in a pandemic-A case study of SARS-CoV-2 and COVID-19

Several efforts to repurpose drugs for COVID-19 treatment have largely either failed to identify a suitable agent or agents identified did not translate to clinical use. Reasons that have been suggested to explain the failures include use of inappropriate doses, that are not clinically achievable, in the screening experiments, and the use of inappropriate pre-clinical laboratory surrogates to predict efficacy. In this study, we used an innovative algorithm, that incorporates dissemination and implementation considerations, to identify potential drugs for COVID-19 using iterative computational and wet laboratory methods. The drugs were screened at doses that are known to be achievable in humans. Furthermore, inhibition of viral induced cytopathic effect (CPE) was used as the laboratory surrogate to predict efficacy. Erythromycin, pyridoxine, folic acid and retapamulin were found to inhibit SARS-CoV-2 induced CPE in Vero cells at concentrations that are clinically achievable. Additional studies may be required to further characterize the inhibitions of CPE and the possible mechanisms.

Impact of Thermophysical Properties of High-Alloy Tool Steels on Their Performance in Re-Purposing Applications

Resource efficiency and circularity in the context of sustainability are rapidly gaining importance in the steel industry. One concept regarding circular economy is "repurposing". In the context of this work, worn-out machine circular knives are used to produce new chisels for woodturning. The chisels can be extracted parallel or perpendicular to the rolling direction of the primary production process, resulting in an associated carbide orientation of the repurposed tool. The rolling direction, and therefore carbide alignment, will influence the wear resistance and the thermophysical properties, whereby the thermal conductivity will determine the temperatures at the tip of the chisel. Therefore, the thermal conductivity was investigated with the dynamic measurement method, where the specific heat capacity, density and thermal diffusivity of the extracted chisels and industrial reference chisels were measured separately. Moreover, the electrical resistivity was measured in order to calculate the electronic thermal conductivity according to the Wiedemann-Franz-Lorenz law. It was shown that all of these parameters exhibited different degrees of variability with rising temperature. In a detailed analysis, the thermal diffusivity could be identified as an essential parameter of thermal conductivity. By taking two conventional chisels with different chemical compositions and heat treatments into account, it can be seen that the microstructure determines the thermophysical properties. Considering the carbide direction, the chisels that were extracted parallel to the rolling direction showed differing thermophysical properties. Therefore, the carbide orientation is shown to play a significant role regarding the heat dissipation at the cutting edge, because differences, especially in the electronic thermal conductivity in the parallel and perpendicular extracted chisels, can be measured. In addition to the wear resistance factor, the thermal conductivity factor now also supports the removal of the repurposed chisels parallel to the rolling direction.

Metformin: A promising drug for human cancers

Small-molecule chemical drugs are of great significance for tumor-targeted and individualized therapies. However, the development of new small-molecule drugs, from basic experimental research and clinical trials to final application in clinical practice, is a long process that has a high cost. It takes at least 5 years for most drugs to be developed in the laboratory to prove their effectiveness and safety. Compared with the development of new drugs, repurposing traditional non-tumor drugs can be a shortcut. Metformin is a good model for a new use of an old drug. In recent years, the antitumor efficacy of metformin has attracted much attention. Epidemiological data and in vivo, and in vitro experiments have shown that metformin can reduce the incidence of cancer in patients with diabetes and has a strong antagonistic effect on metabolism-related tumors. Recent studies have shown that metformin can induce autophagy in esophageal cancer cells, mainly by inhibiting inflammatory signaling pathways. In recent years, studies have shown that the antitumor functions and mechanisms of metformin are multifaceted. The present study aims to review the application of metformin in tumor prevention and treatment.

Molecular docking and dynamics simulation analysis of nucleoprotein from the Crimea-Congo hemorrhagic fever virus strain Baghdad-12 with FDA approved drugs

Crimea-Congo hemorrhagic fever virus is considered a potential public health threat due to the high case fatality ratio of the disease hemorrhagic phase and absence of approved vaccines or antiviral agents. Therefore, it is of interest to screen FDA approved drugs against the nucleoprotein crystal of Crimea-Congo hemorrhagic fever virus strain Baghdad-12 by using molecular docking and dynamics simulation. Hence, we report that the beta receptor blocker Nebivolol and the antihistamine Loratadine may bind to RNA binding region on nucleoprotein for further consideration in drug design and development.

Quest for a Cure: Potential Small-Molecule Treatments for COVID-19, Part 2

During the first year of the outbreak of the COVID-19 pandemic, many drugs and drug candidates have been evaluated as treatment options. None yet has proved to be an effective cure, but progress in controlling the disease has been made. In June 2020 we published an article that described the mechanistic rationale behind the repurposing of seven licensed drugs in clinical trials for the treatment of COVID-19 and reviewed synthetic routes to these drugs. Several developments have occurred since then. Remdesivir (trade name Veklury) has been approved for use in the U.S. and Europe. Dexamethasone, a steroid drug first approved in 1959, has shown mortality reduction in severe COVID patients. Molnupiravir, a new and promising oral antiviral drug, is being studied in late-stage clinical trials. In this review, we update synthetic work that has been recently published on remdesivir, provide an overview of several routes to molnupiravir, and review classical routes to dexamethasone as well as some of those more recently developed.

Soft and Condensed Nanoparticles and Nanoformulations for Cancer Drug Delivery and Repurpose

Drug repurpose or reposition is recently recognized as a high-performance strategy for developing therapeutic agents for cancer treatment. This approach can significantly reduce the risk of failure, shorten R&D time, and minimize cost and regulatory obstacles. On the other hand, nanotechnology-based delivery systems are extensively investigated in cancer therapy due to their remarkable ability to overcome drug delivery challenges, enhance tumor specific targeting, and reduce toxic side effects. With increasing knowledge accumulated over the past decades, nanoparticle formulation and delivery have opened up a new avenue for repurposing drugs and demonstrated promising results in advanced cancer therapy. In this review, recent developments in nano-delivery and formulation systems based on soft (i.e., DNA nanocages, nanogels, and dendrimers) and condensed (i.e., noble metal nanoparticles and metal-organic frameworks) nanomaterials, as well as their theranostic applications in drug repurpose against cancer are summarized.

Why Do Promising Therapies Stall in Development and How Can We Move Them Forward?

There are many reasons that molecules fail to progress to market and various principles of risk-benefit decisions that can help drive the molecule through development. This symposium included discussions on global strategies involved in pushing promising molecules to market, what to do when a molecule stalls in its progress to market, and options for rescuing the molecule and pushing it forward again. Innovative partnerships that bring stalled drugs back into clinical development were also addressed. A regulatory perspective on common reasons for a molecule to fail in its forward progress was presented. In addition, situations arise when a third-party advisory committee can provide input to help overcome issues identified by a regulatory agency. Using examples from the private and public domain, presentations centered on how to repurpose a molecule and when more science is needed.

Applying Erikson's wisdom to self-management practices of older adults: findings from two field studies

According to Erik Erikson's theory on the stages of human development, achieving wisdom later in life involves revisiting previous crises and renewing psychosocial accomplishments. However, few studies have used Erikson's theory as a framework for examining how older adults self-manage physical and mental health changes that commonly occur later in life. This article presents findings from two qualitative studies that demonstrate how older adults apply wisdom in new domains. Specifically, it was found that older adults (1) reasserted autonomy by initiating creative problem solving and (2) applied skills gained from productive activities earlier in life to new health-related problems that arise later in life. These findings highlight the importance of engaging older adults to repurpose their life skills and thus reapply wisdom to new areas of their lives. Implications for practice are discussed.