Indirubin 3'-oxime inhibits anticancer agent-induced YB-1 nuclear translocation in HepG2 human hepatocellular carcinoma cells

Indirubin-3'-oxime as a dual-action agent: mitigating heat-induced male infertility in Drosophila melanogaster and inhibiting soluble epoxide hydrolase

This study investigated the potential of the indirubin-3'-oxime (I3O) compound to mitigate temperature-induced male infertility in Drosophila melanogaster. Elevated temperatures significantly reduced egg-hatching rates, but I3O supplementation improved these rates, suggesting it can partially restore fertility under heat stress. Additionally, I3O was found to inhibit soluble epoxide hydrolase (sEH), an enzyme involved in the metabolism of epoxyeicosatrienoic acids, which are vital for reproductive health. I3O exhibited sEH inhibitions with an IC50 value of 59.74 ± 0.41 µM. Enzyme kinetics revealed that I3O acts as a non-competitive inhibitor of sEH with a Ki value of 78.88 µM. Molecular docking showed strong interactions between I3O and key residues in the allosteric regions within the sEH enzyme, with a binding affinity of -9.2 kcal/mol. These interactions were supported by 100 ns molecular dynamics simulations, which confirmed the stability of the sEH-I3O complex.

Synthesis and DFT calculations of metal(II) oxime complexes bearing cysteine as coligand and investigation of their biological evolutions in vitro and in silico

New complexes with the formula of [ML(Cys)(H2O)2] were obtained as a result of the reaction between the oxime ligand [HL: 4-(4-bromophenylaminoisonitrosoacetyl)biphenyl], cysteine (Cys), and the metal(II) salts (Mn, Ni, Co, Zn, Cu). The newly synthesized compounds were characterized using conventional techniques such as molar conductance, magnetic measurements, elemental analysis, infrared spectroscopy, and thermal analysis (TGA/DTA). Based on the conductivity measurements in DMF, it was determined that the complexes were non-electrolytes. The TGA/DTA analysis was performed to examine the thermal stability and degradation behavior of all samples, and results demonstrated that metal oxides or sulfides formed as a result of the decompositions. In conjunction with other data obtained, the elemental analysis confirmed the octahedral coordination of the complexes with deprotonated oxime (O, O-donor) and amino acid (N, S-donor) ligands and two coordinated waters. The compounds' optimized geometries, molecular electrostatic potential diagrams, and frontier molecular orbitals were computed at the DFT/B3LYP level using the 6-311 G(d,p) and LANL2DZ basis sets. The antibacterial and DNA cleavage activities of all synthesized compounds were also screened, and molecular docking simulations were performed. According to the results of molecular docking studies conducted with three different proteins, the best interaction was found to be between HL-1HNJ with a binding energy of -9.5 kcal/mol. The stability of the HL-1HNJ complex was also verified by a molecular dynamics simulation performed for 50 ns.Communicated by Ramaswamy H. Sarma.

Bromo-substituted indirubins for inhibition of protein kinase-mediated signalling involved in inflammatory mediator release in human monocytes

Targeting protein kinases that regulate signalling pathways in inflammation is an effective pharmacological approach to alleviate uncontrolled inflammatory diseases. In this context, the natural product indirubin and its 6-bromo-substituted analogue 6-bromoindirubin-3 -glycerol-oxime ether (6BIGOE; 1) were identified as potent inhibitors of glycogen synthase kinase-3β (GSK-3β). These inhibitors suppress the release of pro-inflammatory cytokines and prostaglandins (PG) from human monocytes. However, indirubin derivatives target several protein kinases such as cyclin-dependent kinases (CDKs) which has been a major concern for their application in inflammation therapy. Here, we report on a library of 13 5-bromo-substituted indirubin derivatives that have been designed to improve potency and target selectivity. Side-by-side comparison of reference compound 1 (6BIGOE) with 5-bromo derivatives revealed its isomer 2 (5BIGOE), as the most potent derivative able to supress pro-inflammatory cytokine and PG release in lipopolysaccharide-stimulated human monocytes. Analysis of protein kinase inhibition in intact monocytes, supported by our in silico findings, proposed higher selectivity of 1 for GSK-3β inhibition with lesser potency against CDKs 8 and 9. In contrast, 2 supressed the activity of these CDKs with higher effectiveness than GSK-3β, representing additional targets of indirubins within the inflammatory response. Encapsulation of 1 and 2 into polymer-based nanoparticles (NP) improved their pharmacological potential. In conclusion, the 5- and 6-brominated indirubins 1 and 2 as dual GSK-3β and CDK8/9 inhibitors represent a novel concept for intervention with inflammatory disorders.

Potential therapeutic strategies for targeting Y-box-binding protein 1 in cancers

As one of the most conservative proteins in evolution, Y-box-binding protein 1 (YB-1) has long been considered as a potential cancer target. YB-1 is usually poorly expressed in normal cells and exerts cellular physiological functions such as DNA repair, pre-mRNA splicing and mRNA stabilizing. In cancer cells, the expression of YB-1 is up-regulated and undergoes nuclear translocation and contributes to tumorigenesis, angiogenesis, tumor proliferation, invasion, migration and chemotherapy drug resistance. During the past decades, a variety of pharmacological tools such as siRNA, shRNA, microRNA, circular RNA, lncRNA and various compounds have been developed to target YB-1 for cancer therapy. In this review, we describe the physiological characteristics of YB-1 in detail, highlight the role of YB-1 in tumors and summarize the current therapeutic methods for targeting YB-1 in cancer.

Y-box binding protein 1 augments sorafenib resistance via the PI3K/Akt signaling pathway in hepatocellular carcinoma

BACKGROUND

Sorafenib is the first-line treatment for patients with advanced hepatocellular carcinoma (HCC). Y-box binding protein 1 (YB-1) is closely correlated with tumors and drug resistance. However, the relationship between YB-1 and sorafenib resistance and the underlying mechanism in HCC remain unknown.

AIM

To explore the role and related mechanisms of YB-1 in mediating sorafenib resistance in HCC.

METHODS

The protein expression levels of YB-1 were assessed in human HCC tissues and adjacent nontumor tissues. Next, we constructed YB-1 overexpression and knockdown hepatocarcinoma cell lines with lentiviruses and stimulated these cell lines with different concentrations of sorafenib. Then, we detected the proliferation and apoptosis in these cells by terminal deoxynucleotidyl transferase dUTP nick end labeling, flow cytometry and Western blotting assays. We also constructed a xenograft tumor model to explore the effect of YB-1 on the efficacy of sorafenib in vivo. Moreover, we studied and verified the specific molecular mechanism of YB-1 mediating sorafenib resistance in hepatoma cells by digital gene expression sequencing (DGE-seq).

RESULTS

YB-1 protein levels were found to be higher in HCC tissues than in corresponding nontumor tissues. YB-1 suppressed the effect of sorafenib on cell proliferation and apoptosis. Consistently, the efficacy of sorafenib in vivo was enhanced after YB-1 was knocked down. Furthermore, KEGG pathway enrichment analysis of DGE-seq demonstrated that the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was essential for the sorafenib resistance induced by YB-1. Subsequently, YB-1 interacted with two key proteins of the PI3K/Akt signaling pathway (Akt1 and PIK3R1) as shown by searching the BioGRID and HitPredict websites. Finally, YB-1 suppressed the inactivation of the PI3K/Akt signaling pathway induced by sorafenib, and the blockade of the PI3K/Akt signaling pathway by LY294002 mitigated YB-1-induced sorafenib resistance.

CONCLUSION

Overall, we concluded that YB-1 augments sorafenib resistance through the PI3K/Akt signaling pathway in HCC and suggest that YB-1 is a key drug resistance-related gene, which is of great significance for the application of sorafenib in advanced-stage HCC.

Anticancer potential of indirubins in medicinal chemistry: Biological activity, structural modification, and structure-activity relationship

Indirubin is the crucial ingredient of Danggui Longhui Wan and Qing-Dai, traditional Chinese medicine herbal formulas used for the therapy of chronic myelocytic leukemia in China for hundreds of years. Although the monomeric indirubin has been used in China for the treatment human chronic myelocytic leukemia. However, due to low water solubility, poor pharmacokinetic properties and low therapeutic effects are the major obstacle, and had significantly limited its clinical application. Consequently, the attractive anticancer profile of indirubin has enthused numerous researchers to discover novel indirubin derivatives with improved pharmacodynamic activity as well as good pharmacokinetic property. In this paper, we comprehensively review the recent progress of anticancer potential of indirubins, structural modification and structure-activity relationship, which may provide useful direction for the further development of novel indirubins with improved pharmacological profiles for the treatment of various types of cancer.

Prognostic value of aberrantly expressed methylation genes in human hepatocellular carcinoma

Objectives: To identify the prognostic value of aberrantly methylated differentially expressed genes (DEGs) in hepatocellular carcinoma (HCC) and to explore the underlying mechanisms of tumorigenesis.

Methods: Gene expression profiles (GSE65372 and GSE37988) were analyzed using GEO2R to obtain aberrantly methylated DEGs. Functional enrichment analysis of screened genes was performed by the Database for Annotation, Visualization, and Integrated Discovery (DAVID). Cytoscape software was used to analyze the PPI network and to select hub genes. Transcriptional and proteinic expression data of hub genes were obtained through UALCAN and the Human Protein Reference Database. Finally, we analyzed the prognostic value of hub genes with the Kaplan–Meier Plotter and MethSurv database.

Results: In total, 24 up-hypomethylated oncogenes and 37 down-hypermethylated tumor suppressor genes (TSGs) were identified, and 8 hub genes, including 4 up-hypomethylated oncogenes (CDC5L, MERTK, RHOA and YBX1) and 4 down-hypermethylated TSGs (BCR, DFFA, SCUBE2 and TP63), were selected by PPI. Higher expression of methylated CDC5L-cg05671347, MERTK-cg08279316, RHOA-cg05657651 and YBX1-cg16306148, and lower expression of methylated BCR-cg25410636, DFFA-cg20696875, SCUBE2-cg19000089 and TP63-cg06520450, were associated with better overall survival (OS) in HCC patients. Multivariate analysis also showed they were independent prognostic factors for OS of HCC patients.

Conclusions: In summary, different expression of methylated genes above mentioned were associated with better prognosis in HCC patients. Altering the methylation status of these genes may be a therapeutic target for HCC, but it should be further evaluated in clinical studies.

7-Hydorxyindirubin is capable of specifically inhibiting anticancer drug-induced YB-1 nuclear translocation without showing cytotoxicity in HepG2 hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common human malignant tumors. It is known that in the cells of many cancers, including HCC, nuclear translocation and accumulation of YB-1 often indicates a poor prognosis. This nuclear translocation is induced by genotoxic stress resulting from administration of anticancer agents. Accumulation of YB-1 in the nucleus induces the expression of many genes related to cancer aggressiveness. Therefore, compounds capable of inhibiting anticancer drug-induced YB-1 nuclear translocation without cytotoxicity will be a powerful tool for cancer chemotherapy. In the present study, we found that indirubin derivative, 7-hydroxyindirubin strongly inhibited the actinomycin D-induced nuclear translocation of YB-1 more efficiently without showing cytotoxicity in HepG2, a human HCC cells. The compound successfully suppressed the nuclear YB-1-mediated expression of genes such as MDR1, MVP, EGFR, and CXCR4, which are known to disturb cancer treatment. 7-Hydroxyindirubin also increased the susceptibility of drug-resistant HepG2 cells to ActD. It was also demonstrated that 7-hydroxyindirubin inhibits the nuclear translocation of YB-1 with or without phosphorylation at the Ser102 residue.

Y-Box Binding Proteins in mRNP Assembly, Translation, and Stability Control

Y-box binding proteins (YB proteins) are DNA/RNA-binding proteins belonging to a large family of proteins with the cold shock domain. Functionally, these proteins are known to be the most diverse, although the literature hardly offers any molecular mechanisms governing their activities in the cell, tissue, or the whole organism. This review describes the involvement of YB proteins in RNA-dependent processes, such as mRNA packaging into mRNPs, mRNA translation, and mRNA stabilization. In addition, recent data on the structural peculiarities of YB proteins underlying their interactions with nucleic acids are discussed.

Inhibitory Effects of Indirubin-3'-oxime Derivatives on Lipid Accumulation in 3T3-L1 Cells

Obesity elevates the risk of cardiovascular disease and has been strongly associated with increases in the incidence of many metabolic diseases. Therefore, prevention of obesity leads to the prevention of metabolic diseases. In light of this, substances that exert anti-obesity effects are crucial for the prevention of obesity. Indirubin, a 3,2' bisindole isomer of indigo, is the active component of the traditional Chinese medicine used for the treatment of chronic myelocytic leukemia. In particular, indirubin-3'-oxime (1) was shown to inhibit the differentiation of adipocytes. In this study, we investigated the inhibitory effects of nine indirubin-3'-oxime derivatives against lipid accumulation during differentiation in 3T3-L1 cells. Among the compounds tested, 5-methoxyindirubin-3'-oxime (2) and 6-bromoindirubin-3'-oxime (7) at 5 µM exhibited significantly stronger inhibitory activity than indirubin-3'-oxime (1). Furthermore, 5-methoxyindirubin-3'-oxime (2) and 6-bromoindirubin-3'-oxime (7) markedly suppressed the expression of CCAAT/enhancer-binding protein α, peroxisome proliferator activator γ2, and adipocyte protein 2, both of which are key adipogenic regulators at the intermediate stage of adipocyte differentiation. Our results demonstrate that 5-methoxyindirubin-3'-oxime (2) and 6-bromoindirubin-3'-oxime (7) significantly down-regulated lipid accumulation during differentiation of 3T3-L1 cells, suggesting their potential as novel therapeutic drugs against the development of obesity.

YB-3 substitutes YB-1 in global mRNA binding

Y-box binding proteins are DNA- and RNA-binding proteins with an evolutionarily ancient and conserved cold shock domain. The Y-box binding protein 1 (YB-1) is the most studied due to its abundance in somatic cells. YB-1 is involved in a variety of cellular processes, including proliferation, differentiation and stress response. Here, using Ribo-Seq and RIP-Seq we confirm that YB-1 binds a wide range of mRNAs and globally acts as a translation inhibitor. Surprisingly, YBX1 knockout results in only minor alterations in the expression of other genes, mostly caused by changes in RNA abundance. But YB-3 mRNA is an exception: it is better translated in the absence of YB-1, thereby producing an increased amount of YB-3 and thus suggesting that its synthesis is under YB-1 negative control. We have shown that the set of mRNAs bound to YB-3 is strikingly similar to that of YB-1, and that the mRNA-binding by YB-3 is enhanced in the absence of YB-1, resulting in a similar global reduction of translation of bound mRNAs in YB-1-null cells. Thus, YB-3 acts as a substitute for YB-1 in mRNA binding and, probably, in global translational control.

Inhibitory effects of indirubin-3'-monoxime against human osteosarcoma

Indirubin is widely used as the active component of "Dangui Luhui Wan" in ancient China. However, its effects against the osteosarcoma (OS), the most common primary malignancy, are still unknown. In our present study, we investigated the effects of the Indirubin-3'-monoxime (I3M), a derivative of indirubin with better water solubility, against the OS cells. We found I3M inhibited OS cell proliferation in a dose-dependent manner. Flow cytometry assays showed that I3M could not only induce OS cell apoptosis in a time- and dose-dependent manner but also regulate the cell cycle distribution. Additionally, we demonstrated that several Bcl-2 family members, cyclin-dependent kinases (CDKs) and cyclins contributed to this process. Furthermore, out data verified that I3M suppressed OS cell migration and invasion by decreasing MMP-2 and MMP-9 levels. Moreover, survivin and focal adhesion kinase (FAK) might play important roles in the anti-OS effects of I3M. The administration of I3M also inhibited the OS cell growth in mice. Taken together, our results indicated the inhibitory effects of I3M against human OS and thus might be an efficient candidate for OS chemotherapy.