Progress in Redirecting Antiparasitic Drugs for Cancer Treatment

Patient-Derived Organoids on a Microarray for Drug Resistance Study in Breast Cancer

Drug resistance is always a challenge in cancer treatment, whether for chemotherapy, targeting, or immunotherapy. Although tumor cell lines are derived from cancer patients, they gradually lost the original characteristics, including heterogeneity and tumor microenvironment (TME), during the long period of in vitro culturing. Therefore, it is urgent to use patient-derived tumor models instead of cancer cell lines to study tumor drug resistance. Herein, we developed a microarray device that serves as a platform for high-throughput and three-dimensional culture of breast cancer patient-derived organoids (BCOs) and investigated their resistance to adriamycin (ADM). Coupled with fluorescence microscopy, this system enabled on-chip drug response monitoring and cell viability assessment without the consumption of a large number of tumor cells. The organoids were divided into a resistant BCO group (RBCO) and a sensitive BCO group (SBCO) according to their half-inhibitory concentration (IC50). Different from cancer cell lines, BCOs demonstrated obvious heterogeneity in drug treatment. Ivermectin (IVM), a broad-spectrum antiparasitic agent approved by the Food and Drug Administration (FDA), was observed to synergistically augment ADM-induced cytotoxicity in organoids. The BCO chip provides a promising platform for investigation of drug resistance and preclinical drug screening based on clinical samples.

OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN PRESUMED VETERINARY ANTHELMINTIC DRUG-INDUCED RETINAL TOXICITY: A Glimpse into Underlying Mechanism

PURPOSE

To report optical coherence tomography findings of presumed veterinary anthelmintic drugs (VADs)-induced retinal toxicity that may aid in understanding potential pathogenic mechanisms.

METHODS

This is a retrospective observational case series analysis of patients with vision abnormalities following the accidental or intentional consumption of veterinary anthelmintic drugs. All cases underwent a thorough ophthalmological examination. Moreover, medical records, as well as the initial and follow-up optical coherence tomography images, were thoroughly scrutinized.

RESULTS

Four patients were identified (3 men; mean [range] age, 36.5 [22-52] years). Each patient overdosed on one or two of the following VADs: closantel, triclabendazole, praziquantel, pyrantel pamoate, and niclofolan. The most characteristic optical coherence tomography finding was diffuse, granular, hyperreflective lesions throughout the outer retina, which were initially identified in the ellipsoid zone in two cases. At follow-up, optical coherence tomography exhibited regression of hyperreflective lesions and extensive loss of the outer retinal elements in two patients. In addition, the subfoveal outer retinal layers may be partially preserved.

CONCLUSION

Some veterinary anthelmintic drugs could be detrimental to the human retina if overdosed, resulting in visual disturbances. Optical coherence tomography revealed the mitochondria-enriched ellipsoid zone where outer retinal damage first appeared on, implying that these medications may harm the retina by inhibiting mitochondrial energy metabolism, as they do to eliminate parasites.

Pyrimethamine reduced tumour growth in pre-clinical cancer models: a systematic review to identify potential pre-clinical studies for subsequent human clinical trials

Pyrimethamine (PYR), a STAT3 inhibitor, has been shown to reduce tumour burden in mouse cancer models. It is unclear how much of a reduction occurred or whether the PYR dosages and route of administration used in mice were consistent with the FDA's recommendations for drug repurposing. Search engines such as ScienceDirect, PubMed/MEDLINE, and other databases, including Google Scholar, were thoroughly searched, as was the reference list. The systematic review includes fourteen (14) articles. The risk of bias (RoB) was assessed using SYRCLE's guidelines. Due to the heterogeneity of the data, no meta-analysis was performed. According to the RoB assessment, 13/14 studies fall into the moderate RoB category, with one study classified as high RoB. None adhered to the ARRIVE guideline for transparent research reporting. Oral (FDA-recommended) and non-oral routes of PYR administration were used in mice, with several studies reporting very high PYR dosages that could lead to myelosuppression, while oral PYR dosages of 30 mg/kg or less are considered safe. Direct human equivalent dose translation is probably not the best strategy for comparing whether the used PYR dosages in mice are in line with FDA-approved strength because pharmacokinetic profiles, particularly PYR's half-life (t1/2), between humans (t1/2 = 96 h) and mice (t1/2 = 6 h), must also be considered. Based on the presence of appropriate control and treatment groups, as well as the presence of appropriate clinically proven chemotherapy drug(s) for comparison purposes, only one study (1/14) involving liver cancer can be directed into a clinical trial. Furthermore, oesophageal cancer too can be directed into clinical trials, where the indirect effect of PYR on the NRF2 gene may suppress oesophageal cancer in patients, but this must be done with caution because PYR is an investigational drug for oesophageal cancer, and combining it with proven chemotherapy drug(s) is recommended.

Ivermectin: A Multifaceted Drug With a Potential Beyond Anti-parasitic Therapy

Ivermectin was first discovered in the 1970s by Japanese microbiologist Satoshi Omura and Irish parasitologist William C. Campbell. Ivermectin has become a versatile pharmaceutical over the past 50 years. Ivermectin is a derivative of avermectin originally used to treat parasitic infections. Emerging literature has suggested that its role goes beyond this and may help treat inflammatory conditions, viral infections, and cancers. Ivermectin's anti-parasitic, anti-inflammatory, anti-viral, and anticancer effects were explored. Its traditional mechanism of action in parasitic diseases, such as scabies and malaria, rests on its ability to interfere with the glutamate-gated chloride channels in invertebrates and the lack of P-glycoprotein in many parasites. More recently, it has been discovered that the ability of ivermectin to block the nuclear factor kappa-light-chain enhancer of the activated B (NF-κB) pathway that modulates the expression and production of proinflammatory cytokines is implicated in its role as an anti-inflammatory agent to treat rosacea. Ivermectin has also been evaluated for treating infections caused by viruses, such as SARS-CoV-2 and adenoviruses, through inhibition of viral protein transportation and acting on the importin α/β1 interface. It has also been suggested that ivermectin can inhibit the proliferation of tumorigenic cells through various pathways that lead to the management of certain cancers. The review aimed to evaluate its multifaceted effects and potential clinical applications beyond its traditional use as an anthelmintic agent.

Ivermectin as a potential therapeutic strategy for glioma

Ivermectin (IVM), a semi-synthetic macrolide parasiticide, has demonstrated considerable effectiveness in combating internal and external parasites, particularly nematodes and arthropods. Its remarkable ability to control parasites has earned it significant recognition, culminating in Satoshi Omura and William C. Campbell's receipt of the 2015 Nobel Prize in Physiology or Medicine for their contributions to the development of IVM. In recent years, investigations have revealed that IVM possesses antitumor properties. It can suppress the growth of various cancer cells, including glioma, through a multitude of mechanisms such as selective targeting of tumor-specific proteins, inducing programmed cell death, and modulation of tumor-related signaling pathways. Hence, IVM holds tremendous potential as a novel anticancer drug. This review seeks to provide an overview of the underlying mechanisms that enable IVM's capacity to suppress glioma. Furthermore, it aims to elucidate the challenges and prospects associated with utilizing IVM as a new anticancer agent.

The pipeline for drugs for control and elimination of neglected tropical diseases: 2. Oral anti-infective drugs and drug combinations for off-label use

In its 'Road map for neglected tropical diseases 2021-2030', the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for 'off-label' use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with 'off-label' treatment of diseases with insufficient treatment options as pursued by the 'CURE ID' initiative.

The nucleolus of Giardia and its ribosomal biogenesis

Giardia duodenalis is a protozoan intestinal parasite that causes a significant number of infections worldwide each year, particularly in low-income and developing countries. Despite the availability of treatments for this parasitic infection, treatment failures are alarmingly common. As a result, new therapeutic strategies are urgently needed to effectively combat this disease. On the other hand, within the eukaryotic nucleus, the nucleolus stands out as the most prominent structure. It plays a crucial role in coordinating ribosome biogenesis and is involved in vital processes such as maintaining genome stability, regulating cell cycle progression, controlling cell senescence, and responding to stress. Given its significance, the nucleolus presents itself as a valuable target for selectively inducing cell death in undesirable cells, making it a potential avenue for anti-Giardia treatments. Despite its potential importance, the Giardia nucleolus remains poorly studied and often overlooked. In light of this, the objective of this study is to provide a detailed molecular description of the structure and function of the Giardia nucleolus, with a primary focus on its involvement in ribosomal biogenesis. Likewise, it discusses the targeting of the Giardia nucleolus as a therapeutic strategy, its feasibility, and the challenges involved.

Antiangiogenic Activity of Quinine Alone and in Combination with vitamin C in both ex vivo and in vivo Assays

BACKGROUND

Angiogenesis is the process of vascularization from preexisting blood vessels. It is essential for many physiological and pathological processes. Quinine is an anti-malarial agent belongs to the quinoline alkaloid that can inhibit angiogenesis. Vitamin C is also an important antioxidant and has been shown to reduce angiogenesis in tumor.

OBJECTIVE

The study was aimed at investigating the effect of quinine alone and in combination with vitamin C on angiogenesis process.

MATERIALS AND METHODS

12 to 14 weeks old male albino rats were used for the study. Quinine was prepared by dissolving in DMSO and was serially diluted. The rat aorta ring assay was employed to investigate the antiangiogenic effect of quinine ex vivo. An in vivo chorioallantoic membrane (CAM) assay was used to measure the blood vessels inhibition zone by quinine. The zone of inhibition was calculated as the mean inhibition area of a blood vessel in mm±SD.The obtained data were statistically analyzed.

RESULTS

The results revealed that quinine has a significant dose-dependent inhibition effect on the growth of blood vessels by 98% ± 0.07 in concentration 100µg/ml when compared to the negative control. moreover, the inhibition of blood vessels growth as a measure of the antiangiogenic activity of quinine in combination with vitamin C shows a synergistic effect when the concentration that inhibit 50% of blood vessels growth (IC50) which equals to 5.05 µg/ml resulted in 85% of growth inhibition when combined with IC50 of vitamin C which equals to 22..87µg/ml.

CONCLUSION

The findings suggest that the activity of quinine with vitamin C synergism can greatly lower blood vessels growth in rat aorta rings and CAM assays. Quininehas an inhibitory effect on tumor and can be utilized as an antiangiogenic agent alone or in combination with vitamin C.

A Novel Protocol for the Synthesis of 1,2,4-Oxadiazoles Active against Trypanosomatids and Drug-Resistant Leukemia Cell Lines

Cancer and parasitic diseases, such as leishmaniasis and Chagas disease, share similarities that allow the co-development of new antiproliferative agents as a strategy to quickly track the discovery of new drugs. This strategy is especially interesting regarding tropical neglected diseases, for which chemotherapeutic alternatives are extremely outdated. We designed a series of (E)-3-aryl-5-(2-aryl-vinyl)-1,2,4-oxadiazoles based on the reported antiparasitic and anticancer activities of structurally related compounds. The synthesis of such compounds led to the development of a new, fast, and efficient strategy for the construction of a 1,2,4-oxadiazole ring on a silica-supported system under microwave irradiation. One hit compound (23) was identified during the in vitro evaluation against drug-sensitive and drug-resistant chronic myeloid leukemia cell lines (EC₅₀ values ranging from 5.5 to 13.2 µM), Trypanosoma cruzi amastigotes (EC₅₀ = 2.9 µM) and Leishmania amazonensis promastigotes (EC₅₀ = 12.2 µM) and amastigotes (EC₅₀ = 13.5 µM). In silico studies indicate a correlation between the in vitro activity and the interaction with tubulin at the colchicine binding site. Furthermore, ADMET in silico predictions indicate that the compounds possess a high druggability potential due to their physicochemical, pharmacokinetic, and toxicity profiles, and for hit 23, it was identified by multiple spectroscopic approaches that this compound binds with human serum albumin (HSA) via a spontaneous ground-state association with a moderate affinity driven by entropically and enthalpically energies into subdomain IIA (site I) without significantly perturbing the secondary content of the protein.

Bupivacaine modulates the apoptosis and ferroptosis in bladder cancer via phosphatidylinositol 3-kinase (PI3K)/AKT pathway

The study aimed to explore the effects of local anesthetic bupivacaine on bladder cancer cells in vivo and in vitro. The cytotoxicity was detected by MTT assay. Apoptosis was measured by Hoechst 33342 staining and TUNEL. The contents of Fe²⁺, Malondialdehyde (MDA), Glutathione (GSH) and reactive oxygen species (ROS) were evaluated by the corresponding kit. Mitochondrial membrane potential was assessed by JC-1 kit. HE staining, TUNEL and immunohistochemistry were used to detect the xenografted tumors. Protein expression was estimated by Western blot. Bupivacaine significantly inhibited the activity of T24 cells and 5637 cells at 0.25-16 mM. Bupivacaine promoted cell apoptosis with increased concentration. bupivacaine inhibited the expression of Bcl-2 and increased the expression of Bax and cytochrome C. Moreover, bupivacaine amplified the level of Fe²⁺ and ROS, and restrained the expression of cystine/glutamic acid reverse transporter (xCT) and glutathione peroxidase 4 (GPX4). Further results showed that bupivacaine decreased mitochondrial membrane potential, reduced GSH, and increased MDA levels. Besides, bupivacaine attenuated the phosphorylation of PI3K, Akt, and mTOR. In addition, bupivacaine suppressed the growth of xenografted tumors, induced apoptosis and ferroptosis, and inhibited the activity of PI3K/AKT signaling pathway in xenografted tumors. Bupivacaine could induce apoptosis and ferroptosis by inhibiting PI3K/Akt signaling pathway in bladder cancer cells.

The multifaceted antineoplastic role of pyrimethamine against different human malignancies

Cancer accounted for nearly 10 million deaths in 2020 and is the second leading cause of death worldwide. The chemotherapeutic agents that are in clinical practice possess a broad range of severe adverse effects towards vital organs which emphasizes the importance of the discovery of new therapeutic agents or repurposing of existing drugs for the treatment of human cancers. Pyrimethamine is an antiparasitic drug used for the treatment of malaria and toxoplasmosis with a well-documented excellent safety profile. In the last five years, numerous efforts have been made to explore the anticancer potential of pyrimethamine in in vitro and in vivo preclinical models and to repurpose it as an anticancer agent. The studies have demonstrated that pyrimethamine inhibits oncogenic proteins such as STAT3, NF-κB, DX2, MAPK, DHFR, thymidine phosphorylase, telomerase, and many more in a different types of cancer models. Moreover, pyrimethamine has been reported to work in synergy with other anticancer agents, such as temozolomide, to induce apoptosis of tumor cells. Recently, the results of phase-1/2 clinical trials demonstrated that pyrimethamine administration reduces the expression of STAT3 signature genes in tumor tissues of chronic lymphocytic leukemia patients with a good therapeutic response. In the present article, we have reviewed most of the published papers related to the antitumor effects of pyrimethamine in malignancies of breast, liver, lung, skin, ovary, prostate, pituitary, and leukemia in in vitro and in vivo settings. We have also discussed the pharmacokinetic profile and results of clinical trials obtained after pyrimethamine treatment. From these studies, we believe that pyrimethamine has the potential to be repurposed as an anticancer drug. This article is protected by copyright. All rights reserved.

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.