Antitumor Activity of Nitazoxanide against Colon Cancers: Molecular Docking and Experimental Studies Based on Wnt/β-Catenin Signaling Inhibition

Differential toxic and antiepileptic features of Vigabatrin raceme and its enantiomers

BACKGROUND

The study aimed to investigate the potential pharmacological and toxicological differences between Vigabatrin (VGB) and its enantiomers S-VGB and R-VGB. The researchers focused on the toxic effects and antiepileptic activity of these compounds in a rat model.

METHODS

The epileptic rat model was established by intraperitoneal injection of kainic acid, and the antiepileptic activity of VGB, S-VGB, and VGB was observed, focusing on the improvements in seizure latency, seizure frequency and sensory, motor, learning and memory deficits in epileptic rats, as well as the hippocampal expression of key molecular associated with synaptic plasticity and the Wnt/β-catenin/GSK 3β signaling pathway. The acute toxic test was carried out and the LD50 was calculated, and tretinal damages in epileptic rats were also evaluated.

RESULT

The results showed that S-VGB exhibited stronger antiepileptic and neuroprotective effects with lower toxicity compared to VGB raceme. These findings suggest that S-VGB and VGB may modulate neuronal damage, glial cell activation, and synaptic plasticity related to epilepsy through the Wnt/β-catenin/GSK 3β signaling pathway. The study provides valuable insights into the potential differential effects of VGB enantiomers, highlighting the potential of S-VGB as an antiepileptic drug with reduced side effects.

CONCLUSION

S-VGB has the highest antiepileptic effect and lowest toxicity compared to VGB and R-VGB.

Discovery of Cytotoxic Nitric Oxide-Releasing Piperlongumine Derivatives Targeting Wnt/β-Catenin in Colon Cancer Cells

Piperlongumine (1) increases reactive oxygen species (ROS) levels and induces apoptosis in cancer cells through various pathways. Nitric oxide (NO) donors have demonstrated potent anticancer activities with exogenous NO being oxidized by ROS in the tumor microenvironment to form highly reactive N-oxides (RNOS). This amplifies oxidative stress cascade reactions, ultimately inducing cancer cell apoptosis. To exploit this synergy, a series of NO-releasing piperlongumine derivatives (2-5) were designed and synthesized. These compounds were expected to release NO in cancer cells, simultaneously generating piperlongumine derivative fragments to enhance the anticancer effects. Compound 6, structurally similar to compounds 2-5 but not releasing NO, served as a control. Among these derivatives, compound 5 exhibited the most potent antiproliferative activity against HCT-116 cells and efficiently released NO in this cell line. Further investigation revealed that compound 5 inhibited colon cancer cell proliferation by modulating β-catenin expression, which is a pivotal protein in the Wnt/β-catenin signaling pathway. These findings highlight compound 5 as a promising candidate for colon cancer treatment targeting the Wnt/β-catenin pathway.

Chemotherapeutic potential of betanin/capecitabine combination targeting colon cancer: experimental and bioinformatic studies exploring NFκB and cyclin D1 interplay

Introduction: Betanin (C₂₄H₂₆N₂O₁₃) is safe to use as food additives approved by the FDA with anti-inflammatory and anticancer effects in many types of cancer cell lines. The current experiment was designed to test the chemotherapeutic effect of the combination of betanin with the standard chemotherapeutic agent, capecitabine, against chemically induced colon cancer in mice. Methods: Bioinformatic approach was designed to get information about the possible mechanisms through which the drugs may control cancer development. Five groups of mice were assigned as, (i) saline, (ii) colon cancer, (iii) betanin, (iv) capecitabine and (v) betanin/capecitabine. Drugs were given orally for a period of six weeks. Colon tissues were separated and used for biological assays and histopathology. Results: In addition, the mRNA expression of TNF-α (4.58-fold), NFκB (5.33-fold), IL-1β (4.99-fold), cyclin D1 (4.07-fold), and IL-6 (3.55-fold) and protein levels showed several folds increases versus the saline group. Tumor histopathology scores in the colon cancer group (including cryptic distortion and hyperplasia) and immunostaining for NFκB (2.94-fold) were high while periodic-acid Schiff staining demonstrated poor mucin content (33% of the saline group). These pathologic manifestations were reduced remarkably in betanin/capecitabine group. Conclusion: Collectively, our findings demonstrated the usefulness of betanin/capecitabine combination in targeting colon cancer and highlighted that betanin is a promising adjuvant therapy to capecitabine in treating colon cancer patients.

The GSTP1/MAPKs/BIM/SMAC modulatory actions of nitazoxanide: Bioinformatics and experimental evidence in subcutaneous solid Ehrlich carcinoma-inoculated mice

AIMS

Ehrlich ascites carcinoma and its subcutaneous inoculated solid tumour form (SEC) are reliable models for chemotherapeutic molecular targets exploration. Novel chemotherapeutic approaches are identified as molecular targets for intrinsic apoptosis, like the modulation of the second mitochondria-derived activator of caspases (SMAC). SMAC is a physiological substrate of mitogen-activated protein kinases (MAPKs). Glutathione-S-transferase P1 (GSTP1) and its close association with MAPKs play an important role in malignant cell proliferation, metastasis, and resistance to chemotherapeutics. Nitazoxanide (NTZ) is an emerging cancer therapy and its targeted GSTP1 evidence remains a knowledge need.

MAIN METHODS

In the present mice-established SEC, the chemotherapeutic roles of oral NTZ (200 mg/kg/day) and 5-fluorouracil (5-FU; 20 mg/kg/day, intraperitoneally) regimens were evaluated by measuring changes in tumour mass, the tumour MAPKs, cytochrome c, Bcl-2 interacting mediator of cell death (BIM), and SMAC signalling pathway in addition to its molecular downstream; caspases 3 and 9.

KEY FINDINGS

Computational analysis for these target protein interactions showed direct-ordered interactions. After individual therapy with NTZ and 5-FU regimens, the histological architecture of the extracted tumour discs revealed decreases in viable tumour regions with significant necrosis surrounds. These findings were consistent with gross tumour sizes. Each separate regimen lowered the remarkable GSTP1 and elevated the low MAPKs expressions, cytochrome c, BIM, SMAC, and caspases 3, and 9 in EST tissues.

SIGNIFICANCE

The chemotherapeutic activity of NTZ in SEC was proven. Additionally, NTZ possesses a SMAC modulatory activity that, following thorough research, should be taken into consideration as a chemotherapeutic approach in solid tumours.

Nitazoxanide inhibits acetylated KLF5-induced bone metastasis by modulating KLF5 function in prostate cancer

BACKGROUND

Castration-resistant prostate cancer often metastasizes to the bone, and such bone metastases eventually become resistant to available therapies, leading to the death of patients. Enriched in the bone, TGF-β plays a pivotal role in bone metastasis development. However, directly targeting TGF-β or its receptors has been challenging for the treatment of bone metastasis. We previously found that TGF-β induces and then depends on the acetylation of transcription factor KLF5 at K369 to regulate multiple biological processes, including the induction of EMT, cellular invasiveness, and bone metastasis. Acetylated KLF5 (Ac-KLF5) and its downstream effectors are thus potential therapeutic targets for treating TGF-β-induced bone metastasis in prostate cancer.

METHODS

A spheroid invasion assay was applied to prostate cancer cells expressing KLF5^K369Q, which mimics Ac-KLF5, to screen 1987 FDA-approved drugs for invasion suppression. Luciferase- and KLF5^K369Q-expressing cells were injected into nude mice via the tail artery to model bone metastasis. Bioluminescence imaging, micro-CT), and histological analyses were applied to monitor and evaluate bone metastases. RNA-sequencing, bioinformatic, and biochemical analyses were used to understand nitazoxanide (NTZ)-regulated genes, signaling pathways, and the underlying mechanisms. The binding of NTZ to KLF5 proteins was evaluated using fluorescence titration, high-performance liquid chromatography (HPLC), and circular dichroism (CD) analysis.

RESULTS

NTZ, an anthelmintic agent, was identified as a potent invasion inhibitor in the screening and validation assays. In KLF5^K369Q-induced bone metastasis, NTZ exerted a potent inhibitory effect in preventive and therapeutic modes. NTZ also inhibited osteoclast differentiation, a cellular process responsible for bone metastasis induced by KLF5^K369Q. NTZ attenuated the function of KLF5^K369Q in 127 genes' upregulation and 114 genes' downregulation. Some genes' expression changes were significantly associated with worse overall survival in patients with prostate cancer. One such change was the upregulation of MYBL2, which functionally promotes bone metastasis in prostate cancer. Additional analyses demonstrated that NTZ bound to the KLF5 protein, KLF5^K369Q bound to the promoter of MYBL2 to activate its transcription, and NTZ attenuated the binding of KLF5^K369Q to the MYBL2 promoter.

CONCLUSIONS

NTZ is a potential therapeutic agent for bone metastasis induced by the TGF-β/Ac-KLF5 signaling axis in prostate cancer and likely other cancers.

Salicylanilides and Their Anticancer Properties

Salicylanilides are pharmacologically active compounds with a wide spectrum of biological effects. Halogenated salicylanilides, which have been used for decades in human and veterinary medicine as anthelmintics, have recently emerged as candidates for drug repurposing in oncology. The most prominent example of salicylanilide anthelmintic, that is intensively studied for its potential anticancer properties, is niclosamide. Nevertheless, recent studies have discovered extensive anticancer potential in a number of other salicylanilides. This potential of their anticancer action is mediated most likely by diverse mechanisms of action such as uncoupling of oxidative phosphorylation, inhibition of protein tyrosine kinase epidermal growth factor receptor, modulation of different signaling pathways as Wnt/β-catenin, mTORC1, STAT3, NF-κB and Notch signaling pathways or induction of B-Raf V600E inhibition. Here we provide a comprehensive overview of the current knowledge about the proposed mechanisms of action of anticancer activity of salicylanilides based on preclinical in vitro and in vivo studies, or structural requirements for such an activity.

What we have learnt from Drosophila model organism: the coordination between insulin signaling pathway and tumor cells

Cancer development is related to a variety of signaling pathways which mediate various cellular processes including growth, survival, division and competition of cells, as well as cell-cell interaction. The insulin signaling pathway interacts with different pathways and plays a core role in the regulations of all these processes. In this study, we reviewed recent studies on the relationship between the insulin signaling pathway and tumors using the Drosophila melanogaster model. We found that on one hand, the insulin pathway is normally hyperactive in tumor cells, which promotes tumor growth, and on the other hand, tumor cells can suppress the growth of healthy tissues via inhibition of their insulin pathway. Moreover, systematic disruption in glucose homeostasis also facilitates cancer development by different mechanisms. The studies on how the insulin network regulates the behaviors of cancer cells may help to discover new therapeutic treatments for cancer.

Formulation and Characterization of Doxycycline-Loaded Polymeric Nanoparticles for Testing Antitumor/Antiangiogenic Action in Experimental Colon Cancer in Mice

Nanotherapeutics can enhance the characteristics of drugs, such as rapid systemic clearance and systemic toxicities. Polymeric nanoparticles (PRNPs) depend on dispersion of a drug in an amorphous state in a polymer matrix. PRNPs are capable of delivering drugs and improving their safety. The primary goal of this study is to formulate doxycycline-loaded PRNPs by applying the nanoprecipitation method. Eudragit S100 (ES100) (for DOX-PRNP1) and hydroxypropyl methyl cellulose phthalate HP55 (for DOX-PRNP2) were tested as the drug carrying polymers and the DOX-PRNP2 showed better characteristics and drug release % and was hence selected to be tested in the biological study. Six different experimental groups were formed from sixty male albino mice. 1,2,-Dimethylhydrazine was used for 16 weeks to induce experimental colon cancer. We compared the oral administration of DOX-PRNP2 in doses of 5 and 10 mg/kg with the free drug. Results indicated that DOX-PRNP2 had greater antitumor activity, as evidenced by an improved histopathological picture for colon specimens as well as a decrease in the tumor scores. In addition, when compared to free DOX, the DOX-PRNP2 reduced the angiogenic indicators VEGD and CD31 to a greater extent. Collectively, the findings demonstrated that formulating DOX in PRNPs was useful in enhancing antitumor activity and can be used in other models of cancers to verify their efficacy and compatibility with our study.

Oxidative Stress in Intestinal Ischemia-Reperfusion

Ischemia-reperfusion (I/R) injury is a manifestation of tissue or organ damage that is followed by ischemia and exacerbated by the return of blood flow to a previously damaged tissue or organ. The intestines are one of the most sensitive tissues and organs to I/R injury. Moreover, the adverse consequences of intestinal I/R (II/R) injury are not limited to the intestine itself and can also lead to damage of the distant tissues and organs. The mechanism of II/R is extremely complex and oxidative stress is the key link in the pathogenesis of II/R injury. This study summarizes the roles of oxidative stress and its signaling pathways involved in II/R. The signaling pathways that mitigate II/R injury include the nuclear factor erythroid-related factor 2 (Nrf2)-mediated signaling pathway, Wnt/β-catenin pathway, and phosphatidylinositol kinase 3 (PI3K)/Akt pathway; those that aggravate II/R injury include the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, Toll-like receptor (TLR) receptor-mediated signaling pathway, protein kinase CβII (PKCβII)/p66shc pathway, and microRNA (miRNA)/p66shc pathway; the effect of miRNA on related pathways and mitochondrial DNA translocation. The aforementioned pathways provide new ideas for further exploring the occurrence and development of II/R and more effective treatments for II/R injury.