Aurora B kinase: a potential drug target for cancer therapy

AURKB and circAURKB_288aa enhance Esophageal cancer drug resistance through inducing abnormal centrosome separation

Esophageal cancer (EC) is one of the most fatal malignancies worldwide, with a dramatic increase in incidence in the western world occurring over the past few decades. Chromosome instability (CIN) is a major contributor to EC progression, drug resistance, relapse, and the development of intratumoral heterogeneity. This study revealed a striking elevation of AURKB expression in EC patients, with a strong correlation to poor clinical outcomes. AURKB overexpression promoted cellular proliferation and induced drug resistance in both cell culture and animal models. Conversely, genetic targeting of AURKB abrogated these effects. Mechanistically, enforced AURKB expression triggered CIN, a key driver of poor EC outcomes, primarily through CEP250 phosphorylation. Interestingly, we identified a novel circular form of AURKB (circAURKB_288aa) harboring the AURKB kinase domain and encoding a 288-amino acid protein. Elevated levels of circAURKB_288aa in EC peripheral blood samples mirrored poor patient outcomes and synergistically enhanced CIN alongside AURKB. Furthermore, EC cells were capable of secreting circAURKB_288aa, influencing tumor microenvironmental cells similarly to full-length AURKB protein. Notably, AURKB siRNA targeting the shared kinase domain of both AURKB and circAURKB_288aa significantly inhibited EC malignancy. Collectively, these findings establish AURKB and circAURKB_288aa as promising targets for EC prognosis and therapy.

Recent advancements in mechanistic research, therapeutic potential, and structure-activity relationships of aurora kinase inhibitors in cancer therapies

Aurora kinases (AURKs)-a family of serine/threonine protein kinases consisting of AURK-A, AURK-B, and AURK-C, are critical regulators of chromosomal segregation, centrosome maturation, and cytokinesis during the cell cycle. Each kinase is activated via phosphorylation at unique threonine residues: Thr288 (AURK-A), Thr232 (AURK-B), and Thr195 (AURK-C). Activation of AURK-A and AURK-B through phosphorylation triggers a series of downstream signaling pathways, including RalA, NF-κB, p53, PLK1, BRCA1/BRCA2, H2AX, and Kif2C, as well as multiple transmembrane kinase receptors. Dysregulation of these pathways has been implicated in cancer development and progression, positioning AURKs as pivotal targets for anticancer drug research. Inhibition of AURKs has demonstrated significant efficacy in tumor growth suppression and induction of cancer cell death, thereby focusing recent research on the development of potent AURK inhibitors. This review provides an in-depth exploration of AURK inhibitors, discussing their biological activities, structure-activity relationships, selectivity profiles, and mechanisms of action. Notably, compounds 6, 27, and 16 exhibit potent AURK-A inhibition with IC50 values of 1.7 nM, 11.83 nM, and 15 nM, respectively. Similarly, compounds 28, 16, and 7 demonstrate strong AURK-B inhibitory activity, with IC50 values of 10.5 nM, 12 nM, and 14.09 nM, respectively. This comprehensive overview aims to support medicinal chemists in developing more potent, selective, and safe AURK inhibitors as potential anticancer therapeutics.

AURKB targets DHX9 to promote hepatocellular carcinoma progression via PI3K/AKT/mTOR pathway

Aurora kinase B (AURKB) is known to play a carcinogenic role in a variety of cancers, but its underlying mechanism in liver cancer is unknown. This study aimed to investigate the role of AURKB in hepatocellular carcinoma (HCC) and its underlying molecular mechanism. Bioinformatics analysis revealed that AURKB was significantly overexpressed in HCC tissues and cell lines, and its high expression was associated with a poorer prognosis in HCC patients. Furthermore, downregulation of AURKB inhibited HCC cell proliferation, migration, and invasion, induced apoptosis, and caused cell cycle arrest. Moreover, AURKB downregulation also inhibited lung metastasis of HCC. AURKB interacted with DExH-Box helicase 9 (DHX9) and targeted its expression in HCC cells. Rescue experiments further demonstrated that AURKB targeting DHX9 promoted HCC progression through the PI3K/AKT/mTOR pathway. Our results suggest that AURKB is significantly highly expressed in HCC and correlates with patient prognosis. Targeting DHX9 with AURKB promotes HCC progression via the PI3K/AKT/mTOR pathway.

Role of AURKB Inhibition in Reducing Proliferation and Enhancing Effects of Radiotherapy in Triple-Negative Breast Cancer

Breast cancer is a leading cause of cancer-related deaths in females. Triple-negative breast cancer (TNBC) subtype is the most aggressive form of breast cancer that lacks biomarkers and effective targeted therapies. Its high degree of heterogeneity as well as innate and acquired resistance to treatment creates further barriers in achieving positive clinical outcomes in TNBC. Thus, development of novel treatment approaches in TNBC is of high clinical significance. Multimodality approaches with targeted agents and radiotherapy (RT) are promising for increasing efficacy of treatment and circumventing resistance. Here we examined anticancer effects of the Aurora Kinase B (AURKB) inhibitor AZD1152 as a single agent and in combination with RT using various TNBC cell lines, MDA-MB-468, MDA-MB-231 and SUM-159. We observed that AZD1152 alone effectively inhibited colony formation in TNBC cell lines. The combination of AZD1152 at IC50 concentrations together with ionizing radiation further reduced colony formation as compared to the single agent treatment. Our data support the notion that inhibition of the AURKB pathway is a promising strategy for treatment and radiosensitization of TNBC and warrants further translational studies.

MUC1-C Dependence for the Progression of Pancreatic Neuroendocrine Tumors Identifies a Druggable Target for the Treatment of This Rare Cancer

Patients with pancreatic neuroendocrine tumors (pNETs) have limited access to effective targeted agents and invariably succumb to progressive disease. MUC1-C is a druggable oncogenic protein linked to driving pan-cancers. There is no known involvement of MUC1-C in pNET progression. The present work was performed to determine if MUC1-C represents a potential target for advancing pNET treatment. We demonstrate that the MUC1 gene is upregulated in primary pNETs that progress with metastatic disease. In pNET cells, MUC1-C drives E2F- and MYC-signaling pathways necessary for survival. Targeting MUC1-C genetically and pharmacologically also inhibits self-renewal capacity and tumorigenicity. Studies of primary pNET tissues further demonstrate that MUC1-C expression is associated with (i) an advanced NET grade and pathological stage, (ii) metastatic disease, and (iii) decreased disease-free survival. These findings demonstrate that MUC1-C is necessary for pNET progression and is a novel target for treating these rare cancers with anti-MUC1-C agents under clinical development.

An analysis of AURKB's prognostic and immunological roles across various cancers

Aurora kinase B (AURKB), an essential regulator in the process of mitosis, has been revealed through various studies to have a significant role in cancer development and progression. However, the specific mechanisms remain poorly understood. This study, therefore, seeks to elucidate the multifaceted role of AURKB in diverse cancer types. This study utilized bioinformatics techniques to examine the transcript, protein, promoter methylation and mutation levels of AURKB. The study further analysed associations between AURKB and factors such as prognosis, pathological stage, biological function, immune infiltration, tumour mutational burden (TMB) and microsatellite instability (MSI). In addition, immunohistochemical staining data of 50 cases of renal clear cell carcinoma and its adjacent normal tissues were collected to verify the difference in protein expression of AURKB in the two tissues. The results show that AURKB is highly expressed in most cancers, and the protein level of AURKB and the methylation level of its promoter vary among cancer types. Survival analysis showed that AURKB was associated with overall survival in 12 cancer types and progression-free survival in 11 cancer types. Elevated levels of AURKB were detected in the advanced stages of 10 different cancers. AURKB has a potential impact on cancer progression through its effects on cell cycle regulation as well as inflammatory and immune-related pathways. We observed a strong association between AURKB and immune cell infiltration, immunomodulatory factors, TMB and MSI. Importantly, we confirmed that the AURKB protein is highly expressed in kidney renal clear cell carcinoma (KIRC). Our study reveals that AURKB may be a potential biomarker for pan-cancer and KIRC.

Exploring the anticancer potential of fluoro flavone analogues: insights from molecular docking and dynamics studies with Aurora Kinase B

Aurora Kinase B belongs to the serine kinase family. It plays an essential role in cell division and participates in mitosis and chromatid segregation. Overexpression, polymorphism, and splicing variants in the protein lead to tumorigenesis, leading to cancer. Flavones belong to the class of flavonoids and are derived from plants and show anti-cancer activities. Fluoro flavones and their analogs are taken from the PubChem database, resulting in 3882 compounds which is 90% similar to the fluoro flavones. Lipinski's rule of five, REOS and PAINS drug-like filters were applied which resulted 2448 compounds. These compounds are docked with Aurora Kinase B using SP and XP modules of Glide software. The best binding scores for SP docking were - 9.153 kcal/mol for the compound with CID: 44298667, and XP docking was - 10.287 kcal/mol with CID: 101664315. Enrichment calculations were done using Aurora Kinase B's decoys to validate the docking result. The resulting R2 = 0.96 from enrichment calculations suggests that the docking protocol is valid. The SP and XP docking lead compounds and the Fluoro flavone were subjected to 100 ns MD simulation to probe the protein-ligand complex stability. Also, the binding free energies between the Aurora kinase B and lead compounds were computed by Prime MM/GBSA module. The result suggests that the lead compounds bind more strongly with Aurora Kinase B than the Fluoro flavone. These lead compounds can be further evaluated in vitro and in vivo and can be used as future novel drugs for the curation of cancer.

Graphical abstract

The Role of Aurora B Kinase in Normal and Cancer Cells

Aurora kinases are essential players in mammalian cell division. These kinases are involved in the regulation of spindle dynamics, microtubule-kinetochore interactions, and chromosome condensation and orientation during mitosis. At least three members of the Aurora family - Aurora kinases A, B, and C - have been identified in mammals. Aurora B is essential for maintaining genomic stability and normal cell division. Mutations and dysregulation of this kinase are implicated in tumor initiation and progression. In this review, we discuss the functions of Aurora B, the relationship between increased Aurora B activity and carcinogenesis, and the prospects for the use of Aurora B kinase inhibitors in antitumor therapy.

The Aurora kinase B relocation blocker LXY18 triggers mitotic catastrophe selectively in malignant cells

The mitotic regulator, Aurora kinase B (AURKB), is frequently overexpressed in malignancy and is a target for therapeutic intervention. The compound, LXY18, is a potent, orally available small molecule that inhibits the proper localization of AURKB during late mitosis, without affecting its kinase activity. In this study, we demonstrate that LXY18 elicits apoptosis in cancer cells derived from various indications, but not in non-transformed cell lines. The apoptosis is p53-independent, triggered by a prolonged mitotic arrest and occurs predominantly in mitosis. Some additional cells succumb post-mitotic slippage. We also demonstrate that cancer cell lines refractory to AURKB kinase inhibitors are sensitive to LXY18. The mitotic proteins MKLP2, NEK6, NEK7 and NEK9 are known regulators of AURKB localization during the onset of anaphase. LXY18 fails to inhibit the catalytic activity of these AURKB localization factors. Overall, our findings suggest a novel activity for LXY18 that produces a prolonged mitotic arrest and lethality in cancer cells, leaving non-transformed cells healthy. This new activity suggests that the compound may be a promising drug candidate for cancer treatment and that it can also be used as a tool compound to further dissect the regulatory network controlling AURKB localization.

In-silico identification of novel inhibitors for human Aurora kinase B form the ZINC database using molecular docking-based virtual screening

Introduction: Aurora kinase enzymes play critical functions in mammals. Aurora kinases are mitotic regulators that are involved in a variety of processes during cell division. The overexpression of these enzymes is associated with tumour formation and is symptomatic of clinical circumstances in cancer patients who have been diagnosed.

Materials and methods: The current study reports an in-silico virtual screening (VS) and molecular docking analysis of 2500 compounds retrieved from the ZINC database and five current clinical trial compounds against Aurora Kinase B using AutoDock Vina to identify potential inhibitors.

Results and discussion: The top six compounds that resulted from the screening were ZINC00190959, ZINC07889110, ZINC0088285, ZINC01404326, ZINC00882846 and ZINC08813187, which showed lower free energy of binding (FEB) against the target protein binding pocket. The FEB were as follows: -11.92, -11.85, -11.46, -11.33, -11.21 and -11.1 kcal/mol, using AutoDock, and -11.7, -11.5, -11.2, -11.0, -10.8 and -10.6 kcal/mol for AutoDock Vina, respectively. These findings were superior to those obtained with the co-crystallized ligand VX-680, with a -7.5 kcal/mol and the current clinical trial drug. Finally, using a VS and molecular docking approach, novel Aurora kinase B inhibitors were effectively identified from the ZINC database fulfilling the Lipinski rule of five with low FEB and functional molecular interactions with the target protein.

Conclusion: The findings suggest that the six compounds could be used as a potential agent for cancer treatments.

Graphical abstract

Influence of serum vitamin D level in the response of actinic keratosis to ingenol mebutate

Vitamin D (VD) serum levels, and keratinocytic basal expression of vitamin D receptor (VDR) before treatment of actinic keratoses (AK) have been previously reported as possible biomarkers of the response of AK to treatments. We intended to evaluate the association between these and other serum and immunohistochemical parameters with the response of AK to treatment with topical ingenol mebutate (IM). Twenty-five patients with AK on the head were treated with topical IM 0.015% gel once daily for 3 days. Biopsies were taken at baseline and 6 weeks after treatment. Immunohistochemical staining was performed for VDR, P53, Ki67, Aurora B, Survivin and β-catenin. Basal serum 25(OH)D levels were determined. IM was more effective for KIN I and II AKs than in KIN III, and histological responders showed significantly higher serum VD levels (30.278 [SD 8.839] ng/mL) than nonresponders (21.14 [SD 7.079] ng/mL, p = 0.023). In addition, mean basal expression of VDR (45.63 [SD 16.105] %) increased significantly (57.92 [SD 14.738] %, p = 0.003) after treatment with IM. A significant decrease after treatment in the expression of several markers of aggressiveness and progression to squamous cell carcinoma, namely P53, Ki-67, aurora B kinase and survivin, was also observed. Our results support a relationship between VD status and the response of AK to treatment with topical IM, suggesting that its previous correction to proper serum levels in VD-deficient patients could improve the response of AK to the treatment.

The overview of Mitogen-activated extracellular signal-regulated kinase (MEK)-based dual inhibitor in the treatment of cancers

Mitogen-activated extracellular signal-regulated kinase 1 and 2 (MEK1/2) are the critical components of the mitogen-activated protein kinase/extracellular signal-regulated kinase 1 and 2 (MAPK/ERK1/2) signaling pathway which is one of the well-characterized kinase cascades regulating cell proliferation, differentiation, growth, metabolism, survival and mobility both in normal and cancer cells. The aberrant activation of MAPK/ERK1/2 pathway is a hallmark of numerous human cancers, therefore targeting the components of this pathway to inhibit its dysregulation is a promising strategy for cancer treatment. Enormous efforts have been done in the development of MEK1/2 inhibitors and encouraging advancements have been made, including four inhibitors approved for clinical use. However, due to the multifactorial property of cancer and rapidly arising drug resistance, the clinical efficacy of these MEK1/2 inhibitors as monotherapy are far from ideal. Several alternative strategies have been developed to improve the limited clinical efficacy, including the dual inhibitor which is a single drug molecule able to simultaneously inhibit two targets. In this review, we first introduced the activation and function of the MAPK/ERK1/2 components and discussed the advantages of MEK1/2-based dual inhibitors compared with the single inhibitors and combination therapy in the treatment of cancers. Then, we overviewed the MEK1/2-based dual inhibitors for the treatment of cancers and highlighted the theoretical basis of concurrent inhibition of MEK1/2 and other targets for development of these dual inhibitors. Besides, the status and results of these dual inhibitors in both preclinical and clinical studies were also the focus of this review.

Comprehensive Computational Analysis of Honokiol Targets for Cell Cycle Inhibition and Immunotherapy in Metastatic Breast Cancer Stem Cells

Breast cancer stem cells (BCSCs) play a critical role in chemoresistance, metastasis, and poor prognosis of breast cancer. BCSCs are mostly dormant, and therefore, activating them and modulating the cell cycle are important for successful therapy against BCSCs. The tumor microenvironment (TME) promotes BCSC survival and cancer progression, and targeting the TME can aid in successful immunotherapy. Honokiol (HNK), a bioactive polyphenol isolated from the bark and seed pods of Magnolia spp., is known to exert anticancer effects, such as inducing cell cycle arrest, inhibiting metastasis, and overcoming immunotherapy resistance in breast cancer cells. However, the molecular mechanisms of action of HNK in BCSCs, as well as its effects on the cell cycle, remain unclear. This study aimed to explore the potential targets and molecular mechanisms of HNK on metastatic BCSC (mBCSC)-cell cycle arrest and the impact of the TME. Using bioinformatics analyses, we predicted HNK protein targets from several databases and retrieved the genes differentially expressed in mBCSCs from the GEO database. The intersection between the differentially expressed genes (DEGs) and the HNK-targets was determined using a Venn diagram, and the results were analyzed using a protein-protein interaction network, hub gene selection, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, genetic alteration analysis, survival rate, and immune cell infiltration levels. Finally, the interaction between HNK and two HNK-targets regulating the cell cycle was analyzed using molecular docking analysis. The identified potential therapeutic targets of HNK (PTTH) included CCND1, SIRT2, AURKB, VEGFA, HDAC1, CASP9, HSP90AA1, and HSP90AB1, which can potentially inhibit the cell cycle of mBCSCs. Moreover, our results showed that PTTH could modulate the PI3K/Akt/mTOR and HIF1/NFkB/pathways. Overall, these findings highlight the potential of HNK as an immunotherapeutic agent for mBCSCs by modulating the tumor immune environment.

CK1 Is a Druggable Regulator of Microtubule Dynamics and Microtubule-Associated Processes

Protein kinases of the Casein Kinase 1 family play a vital role in the regulation of numerous cellular processes. Apart from functions associated with regulation of proliferation, differentiation, or apoptosis, localization of several Casein Kinase 1 isoforms to the centrosome and microtubule asters also implicates regulatory functions in microtubule dynamic processes. Being localized to the spindle apparatus during mitosis Casein Kinase 1 directly modulates microtubule dynamics by phosphorylation of tubulin isoforms. Additionally, site-specific phosphorylation of microtubule-associated proteins can be related to the maintenance of genomic stability but also microtubule stabilization/destabilization, e.g., by hyper-phosphorylation of microtubule-associated protein 1A and RITA1. Consequently, approaches interfering with Casein Kinase 1-mediated microtubule-specific functions might be exploited as therapeutic strategies for the treatment of cancer. Currently pursued strategies include the development of Casein Kinase 1 isoform-specific small molecule inhibitors and therapeutically useful peptides specifically inhibiting kinase-substrate interactions.

Role of aurora kinase B in regulating resistance to paclitaxel in breast cancer cells

Aurora kinase B (AURKB) is a type of functional kinase with primary functions of participating in cell mitosis, which has been identified to be involved in the occurrence and development of malignant tumors strongly. However, it still remains a controversial with respect to the relationship between the phosphorylation level of AURKB and its function. In our initial research, there was no significant difference in the relative content of AURKB protein between drug-resistant breast cancer cells and wild-type cells; however, its phosphorylation level in drug-resistant cells was significantly higher than that in wild-type cells. Subsequent cell and animal experiments both confirmed the positive correlation between AURKB phosphorylation and drug resistance. Furthermore, PRKCE in the upstream was identified to regulate the phosphorylation of AURKB, which promoted the change of spatial localization of AURKB from nucleus to cytoplasm. Accordingly, phosphorylated AURKB reduced the negative regulation of downstream RAB27B transcription physically, and interacted with RAB27B in cytoplasm to maintain its protein stability. Eventually, it promoted exosome secretion of drug-resistant cells and drug efflux. Using shRNA to knockdown AURKB expression, using hesperadin to inhibit AURKB activity, mutating the AURKB phosphorylation site, or using siRNA as well as BIM to inhibit the activity of the upstream AURKB phosphorylation regulatory protein PRKCE, all of which directly or indirectly reduce AURKB phosphorylation, are effective in reversing PTX resistance in cells. Collectively, this study provides experimental evidence for PRKCE/AURKB/RAB27B axis in regulating the resistance to paclitaxel (PTX) in breast cancer cells, offering a potential intervention target for reversing drug resistance.

Six potential biomarkers for bladder cancer: key proteins in cell-cycle division and apoptosis pathways

BACKGROUND

The bladder cancer (BC) pathology is caused by both exogenous environmental and endogenous molecular factors. Several genes have been implicated, but the molecular pathogenesis of BC and its subtypes remains debatable. The bioinformatic analysis evaluates high numbers of proteins in a single study, increasing the opportunity to identify possible biomarkers for disorders.

METHODS

The aim of this study is to identify biomarkers for the identification of BC using several bioinformatic analytical tools and methods. BC and normal samples were compared for each probeset with T test in GSE13507 and GSE37817 datasets, and statistical probesets were verified with GSE52519 and E-MTAB-1940 datasets. Differential gene expression, hierarchical clustering, gene ontology enrichment analysis, and heuristic online phenotype prediction algorithm methods were utilized. Statistically significant proteins were assessed in the Human Protein Atlas database. GSE13507 (6271 probesets) and GSE37817 (3267 probesets) data were significant after the extraction of probesets without gene annotation information. Common probesets in both datasets (2888) were further narrowed by analyzing the first 100 upregulated and downregulated probesets in BC samples.

RESULTS

Among the total 400 probesets, 68 were significant for both datasets with similar fold-change values (Pearson r: 0.995). Protein-protein interaction networks demonstrated strong interactions between CCNB1, BUB1B, and AURKB. The HPA database revealed similar protein expression levels for CKAP2L, AURKB, APIP, and LGALS3 both for BC and control samples.

CONCLUSION

This study disclosed six candidate biomarkers for the early diagnosis of BC. It is suggested that these candidate proteins be investigated in a wet lab to identify their functions in BC pathology and possible treatment approaches.

Integrative Analysis for Elucidating Transcriptomics Landscapes of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex and heterogeneous autoimmune disease that the immune system attacks healthy cells and tissues. SLE is difficult to get a correct and timely diagnosis, which makes its morbidity and mortality rate very high. The pathogenesis of SLE remains to be elucidated. To clarify the potential pathogenic mechanism of SLE, we performed an integrated analysis of two RNA-seq datasets of SLE. Differential expression analysis revealed that there were 4,713 and 2,473 differentially expressed genes, respectively, most of which were up-regulated. After integrating differentially expressed genes, we identified 790 common differentially expressed genes (DEGs). Gene functional enrichment analysis was performed and found that common differentially expressed genes were significantly enriched in some important immune-related biological processes and pathways. Our analysis provides new insights into a better understanding of the pathogenic mechanisms and potential candidate markers for systemic lupus erythematosus.