Negative Modulation of the Angiogenic Cascade Induced by Allosteric Kinesin Eg5 Inhibitors in a Gastric Adenocarcinoma In Vitro Model

Eg5 and Diseases: From the Well-Known Role in Cancer to the Less-Known Activity in Noncancerous Pathological Conditions

Eg5 is a protein encoded by KIF11 gene and is primarily involved in correct mitotic cell division. It is also involved in nonmitotic processes such as polypeptide synthesis, protein transport, and angiogenesis. The scientific literature sheds light on the ubiquitous functions of KIF11 and its involvement in the onset and progression of different pathologies. This review focuses attention on two main points: (1) the correlation between Eg5 and cancer and (2) the involvement of Eg5 in noncancerous conditions. Regarding the first point, several tumors revealed an overexpression of this kinesin, thus pushing to look for new Eg5 inhibitors for clinical practice. In addition, the evaluation of Eg5 expression represents a crucial step, as its overexpression could predict a poor prognosis for cancer patients. Referring to the second point, in specific pathological conditions, the reduced activity of Eg5 can be one of the causes of pathological onset. This is the case of Alzheimer's disease (AD), in which Aβ and Tau work as Eg5 inhibitors, or in acquired immune deficiency syndrome (AIDS), in which Tat-mediated Eg5 determines the loss of CD4+ T-lymphocytes. Reduced Eg5 activity, due to mutations of KIF11 gene, is also responsible for pathological conditions such as microcephaly with or without chorioretinopathy, lymphedema, or intellectual disability (MCLRI) and familial exudative vitreous retinopathy (FEVR). In conclusion, this review highlights the double impact that overexpression or loss of function of Eg5 could have in the onset and progression of different pathological situations. This emphasizes, on one hand, a possible role of Eg5 as a potential biomarker and new target in cancer and, on the other hand, the promotion of Eg5 expression/activity as a new therapeutic strategy in different noncancerous diseases.

Mitotic Functions and Characters of KIF11 in Cancers

Mitosis mediates the accurate separation of daughter cells, and abnormalities are closely related to cancer progression. KIF11, a member of the kinesin family, plays a vital role in the formation and maintenance of the mitotic spindle. Recently, an increasing quantity of data have demonstrated the upregulated expression of KIF11 in various cancers, promoting the emergence and progression of cancers. This suggests the great potential of KIF11 as a prognostic biomarker and therapeutic target. However, the molecular mechanisms of KIF11 in cancers have not been systematically summarized. Therefore, we first discuss the functions of the protein encoded by KIF11 during mitosis and connect the abnormal expression of KIF11 with its clinical significance. Then, we elucidate the mechanism of KIF11 to promote various hallmarks of cancers. Finally, we provide an overview of KIF11 inhibitors and outline areas for future work.

Cytotoxic monastrol derivatives as adjective inhibitors of drug-resistant Eg5: a molecular dynamics perspective

The mitotic kinesin Eg5 is a motor protein involved in the formation of bipolar spindle and cell division. Eg5 is overexpressed in various cancer cells and Eg5 targeting agents are promising candidates for cancer therapy. Subsequent to the discovery of monastrol as a small-molecule Eg5 modulator, numerous inhibitors/modulators have been reported from which a few entered clinical trials. Mutagenic investigations specified declined sensitivity of Eg5 allosteric site to monastrol due to the occurrence of drug-resistant mutations in some cell cultures. Accordingly, identification of tight binders to the mutant Eg5 allosteric site is an invaluable strategy to devise more efficient Eg5 modulators. We have previously synthesized a few dihydropyrimidinethione (DHPMT)-based 5-carboxamide monastrol derivatives (1-5) with higher cytotoxicities against AGS (IC50 9.90-98.48 µM) and MCF-7 (IC50 15.20-149.13 µM) cancer cell lines than monastrol. Within a current study, a structural insight was offered into the binding mechanism of intended derivatives inside the mutant Eg5 loop5/α2/α3 allosteric pocket. Molecular docking of the DHPMT R and S-enantiomers unraveled top-scored Eg5 complexes. Molecular dynamics (MD) simulations were carried out on 5 superior complexes as (R)-2/D130V-Eg5, (R)-4/D130V-Eg5, (R)-5/D130V-Eg5, (R)-5/L214I-Eg5, (R)-5/R119L-Eg5, and the control groups monastrol/D130V-Eg5, monastrol/L214I-Eg5, monastrol/R119L-Eg5. Free energy calculations were conducted through conformational sampling of MD-driven binding trajectories. Our results provided structural details on probable interaction mechanism of the cytotoxic DHPMTs that are difficult to address experimentally. The outputs of the current study propose new monastrol derivatives as probable resistance-overwhelming Eg5 modulators.Communicated by Ramaswamy H. Sarma.

Antimalarial Agents Targeting Plasmodium falciparum Carbonic Anhydrase: Towards Artesunate Hybrid Compounds with Dual Mechanism of Action

Malaria continues to be a major public health challenge worldwide and, as part of the global effort toward malaria eradication, plasmodium carbonic anhydrases (CAs) have recently been proposed as potential targets for malaria treatment. In this study, a series of eight hybrid compounds combining the Artesunate core with a sulfonamide moiety were synthesized and evaluated for their inhibition potency against the widely expressed human (h) CAs I, II and the isoform from P. falciparum (PfCA). All derivatives demonstrated high inhibition potency against PfCA, achieving a KI value in the sub-nanomolar range (0.35 nM). Two Compounds showed a selectivity index of 4.1 and 3.1, respectively, against this protozoan isoform compared to hCA II. Three Derivatives showed no cytotoxic effects on human gingival fibroblasts at 50 μM with a high killing rate against both P. falciparum and P. knowlesi strains with IC50 in the sub-nanomolar range, providing a wide therapeutic window. Our findings suggest that these compounds may serve as promising leads for developing new antimalarial drugs and warrant further investigation, including activity against antimalarial-resistant strains, mode of action studies, and in vivo efficacy assessment in preclinical mouse models of malaria.

Natural products as a source of new anticancer chemotypes

INTRODUCTION

Exploring the chemical diversity and molecular mechanisms of natural products continues to be an important research area for identifying novel promising therapeutic approaches for fighting cancer. This is a complex disease and poses important challenges, which require not only targeted interventions to improve chemotherapy efficacy and tolerability, but also adjuvant strategies to counteract chemoresistance development and relapses.

AREAS COVERED

After a brief description of the recent literature on the anticancer potential of natural compounds, we searched for patents following the PRISMA guidelines, filtering the results published from 2019 onwards. In addition, some relevant publications from the overall scientific literature were also discussed.

EXPERT OPINION

This review comprehensively covers and analyzes the most recent advances on the anticancer mechanism of licensed natural compounds and their chemical optimization. Patentability of natural compounds was discussed according to the recent legislation in the U.S.A. and Europe.

A nine-gene signature as prognostic biomarker in gastric cancer by bioinformatics analysis

PURPOSE

The prognosis of advanced gastric cancer (GC) remains poor. It is urgent and necessary to find suitable prognostic markers. miR-619-5p is highly expressed in GC. However, the value of miR-619-5p and its target genes as prognostic biomarkers of GC is unclear.

METHODS

RT-PCR was performed to verify the expression of miR-619-5p in GC cell lines and their exosomes. Western blotting and transmission electron microscope were used to identify exosomes. The target genes of miR-619-5p were predicted by RNA22 and TargetScan. The differentially expressed genes (DEGs) and prognosis-related genes (PRGs) were obtained using The Cancer Genome Atlas (TCGA) database. The DAVID database was used to analyse pathway enrichment and functional annotation of common target genes. The STRING database and Cytoscape software were used to screen key genes and visualize their functional modules. The survival analysis was conducted using TCGA and Kaplan-Meier Plotter (KMP) databases. Finally, a prognostic model was constructed on the foundation of the key genes to assess the reliability of the screening process.

RESULTS

The expression of miR-619-5p in GC cells and their exosomes was proved to be significantly higher than that in normal cell lines. There are 129 common target genes involved in 3 pathways and 28 functional annotations. Finally, nine key target genes of GC (BRCA1, RAD51, KIF11, ERCC6L, BRIP1, TIMELESS, CDC25A, CLSPN and NCAPG2) were identified, and a prognostic model was successfully constructed with a good predictive ability.

CONCLUSIONS

The model of 9-gene signature could effectively predict the prognosis of GC, and have great potential to be novel prognostic factors and therapeutic targets for patients with GC.

Hesperidin Reversed Long-Term N-methyl-N-nitro-N-Nitroguanidine Exposure Induced EMT and Cell Proliferation by Activating Autophagy in Gastric Tissues of Rats

Gastric cancer is a common malignant tumor worldwide. N-methyl-N-nitro-N-nitroguanidine (MNNG) is one of the most important inducing factors of gastric cancer. Autophagy can affect the occurrence and development of gastric cancer, but the mechanism is not clear. Chemoprevention has been shown to be a rational and very promising approach to the prevention of gastric cancer. Hesperidin is a citrus flavone, an abundant polyphenol in citrus fruits and traditional Chinese medicine. It has an excellent phytochemistry that plays an intervention role in gastric cancer. However, it is unclear whether long-term exposure to MNNG will affect the occurrence of gastric cancer by regulating autophagy and whether hesperidin can play an intervention role in this process. In the present study, we demonstrated that long-term MNNG exposure inhibits autophagy in stomach tissues of rats, promotes the epithelial-mesenchymal transition (EMT) process and cell proliferation and suppresses the activity of the PI3K/AKT pathway. We further found that after rapamycin-activated autophagy, long-term MNNG exposure promoted cell proliferation and EMT were inhibited. In addition, hesperidin promotes autophagy and the activity of the PI3K/AKT pathway, as well as the suppression of proliferation and EMT in the stomach tissues of rats. Our findings indicate that hesperidin reverses MNNG-induced gastric cancer by activating autophagy and the PI3K/AKT pathway, which may provide a new basis for the early prevention and treatment of MNNG-induced gastric cancer.

Hesperidin inhibits tobacco smoke-induced pulmonary cell proliferation and EMT in mouse lung tissues via the p38 signaling pathway

Tobacco smoke (TS) is the major cause of lung cancer. The abnormal proliferation and epithelial-mesenchymal transition (EMT) of lung cells promote occurrence and development of lung cancer. The p38 pathway intervenes in this cancer development. Hesperidin also serves a role in human health and disease prevention. The roles of p38 in TS-mediated abnormal cell proliferation and EMT, and the hesperidin intervention thereof are not yet understood. In the present study, it was demonstrated that TS upregulated proliferating cell nuclear antigen, vimentin and N-cadherin expression, whereas it downregulated E-cadherin expression, as assessed using western blotting and reverse transcription-quantitative PCR. Furthermore, it was observed that inhibition of the p38 pathway inhibit TS-induced proliferation and EMT. Hesperidin treatment prevented the TS-induced activation of the p38 pathway, EMT and cell proliferation in mouse lungs. The findings of the present study may provide insights into the pathogenesis of TS-related lung cancer.

Kinesin Eg5 Selective Inhibition by Newly Synthesized Molecules as an Alternative Approach to Counteract Breast Cancer Progression: An In Vitro Study

Breast cancer (BC) is one of the most diagnosed cancers in women. Recently, a promising target for BC treatment was found in kinesin Eg5, a mitotic motor protein that allows bipolar spindle formation and cell replication. Thus, the aim of this work was to evaluate the effects of novel thiadiazoline-based Eg5 inhibitors, analogs of K858, in an in vitro model of BC (MCF7 cell line). Compounds 2 and 41 were selected for their better profile as they reduce MCF7 viability at lower concentrations and with minimal effect on non-tumoral cells with respect to K858. Compounds 2 and 41 counteract MCF7 migration by negatively modulating the NF-kB/MMP-9 pathway. The expression of HIF-1α and VEGF appeared also reduced by 2 and 41 administration, thus preventing the recruitment of the molecular cascade involved in angiogenesis promotion. In addition, 2 provokes an increased caspase-3 activation thus triggering the MCF7 apoptotic event, while 41 and K858 seem to induce the necrosis axis, as disclosed by the increased expression of PARP. These results allow us to argue that 2 and 41 are able to simultaneously intervene on pivotal molecular signaling involved in breast cancer progression, leading to the assumption that Eg5 inhibition can represent a valid approach to counteract BC progression.