TonEBP inhibits ciliogenesis by controlling aurora kinase A and regulating centriolar satellite integrity.

BACKGROUND: Primary cilia on the surface of eukaryotic cells serve as sensory antennas for the reception and transmission in various cell signaling pathways. They are dynamic organelles that rapidly form during differentiation and cell cycle exit. Defects in these organelles cause a group of wide-ranging disorders called ciliopathies. Tonicity-responsive enhancer-binding protein (TonEBP) is a pleiotropic stress protein that mediates various physiological and pathological cellular responses. TonEBP is well-known for its role in adaptation to a hypertonic environment, to which primary cilia have been reported to contribute. Furthermore, TonEBP is involved in a wide variety of other signaling pathways, such as Sonic Hedgehog and WNT signaling, that promote primary ciliogenesis, suggesting a possible regulatory role. However, the functional relationship between TonEBP and primary ciliary formation remains unclear. METHODS: TonEBP siRNAs and TonEBP-mCherry plasmids were used to examine their effects on cell ciliation rates, assembly and disassembly processes, and regulators. Serum starvation was used as a condition to induce ciliogenesis. RESULTS: We identified a novel pericentriolar localization for TonEBP. The results showed that TonEBP depletion facilitates the formation of primary cilia, whereas its overexpression results in fewer ciliated cells. Moreover, TonEBP controlled the expression and activity of aurora kinase A, a major negative regulator of ciliogenesis. Additionally, TonEBP overexpression inhibited the loss of CP110 from the mother centrioles during the early stages of primary cilia assembly. Finally, TonEBP regulated the localization of PCM1 and AZI1, which are necessary for primary cilia formation. CONCLUSIONS: This study proposes a novel role for TonEBP as a pericentriolar protein that regulates the integrity of centriolar satellite components. This regulation has shown to have a negative effect on ciliogenesis. Investigations into cilium assembly and disassembly processes suggest that TonEBP acts upstream of the aurora kinase A - histone deacetylase 6 signaling pathway and affects basal body formation to control ciliogenesis. Taken together, our data proposes previously uncharacterized regulation of primary cilia assembly by TonEBP.

Caspase-mediated AURKA cleavage at Asp132 is essential for paclitaxel to elicit cell apoptosis.

Background: Aurora kinase A (AURKA) is a potent oncogene that is often aberrantly expressed during tumorigenesis, and is associated with chemo-resistance in various malignancies. However, the role of AURKA in chemo-resistance remains largely elusive. Methods: The cleavage of AURKA upon viral infection or apoptosis stimuli was assesed by immunoblotting assays in several cancer cells or caspase deficient cell line models. The effect of AURKA cleavage at Asp132 on mitosis was explored by live cell imaging and immunofluorescence staining experiments. The role of Asp132-cleavage of AURKA induced by the chemotherapy drug paclitaxel was investigated using TUNEL, immunohistochemistry assay in mouse tumor xenograft model and patient tissues. Results: The proteolytic cleavage of AURKA at Asp132 commonly occurs in several cancer cell types, regardless of viral infection or apoptosis stimuli. Mechanistically, caspase 3/7/8 cleave AURKA at Asp132, and the Asp132-cleaved forms of AURKA promote cell apoptosis by disrupting centrosome formation and bipolar spindle assembly in metaphase during mitosis. The AURKAD132A mutation blocks the expression of cleaved caspase 3 and EGR1, which leads to reduced therapeutic effects of paclitaxel on colony formation and malignant growth of tumor cells in vitro and in vivo using a murine xenograft model and cancer patients. Conclusions: This study reveals that caspase-mediated AURKAD132 proteolysis is essential for paclitaxel to elicit cell apoptosis and indicates that AURKAD132 is a potential key target for chemotherapy.

Suppressing PD-L1 Expression via AURKA Kinase Inhibition Enhances Natural Killer Cell-Mediated Cytotoxicity against Glioblastoma.

Immunotherapies have shown significant promise as an impactful strategy in cancer treatment. However, in glioblastoma multiforme (GBM), the most prevalent primary brain tumor in adults, these therapies have demonstrated lower efficacy than initially anticipated. Consequently, there is an urgent need for strategies to enhance the effectiveness of immune treatments. AURKA has been identified as a potential drug target for GBM treatment. An analysis of the GBM cell transcriptome following AURKA inhibition revealed a potential influence on the immune system. Our research revealed that AURKA influenced PD-L1 levels in various GBM model systems in vitro and in vivo. Disrupting AURKA function genetically led to reduced PD-L1 levels and increased MHC-I expression in both established and patient-derived xenograft GBM cultures. This process involved both transcriptional and non-transcriptional pathways, partly implicating GSK3ß. Interfering with AURKA also enhanced NK-cell-mediated elimination of GBM by reducing PD-L1 expression, as evidenced in rescue experiments. Furthermore, using a mouse model that mimics GBM with patient-derived cells demonstrated that Alisertib decreased PD-L1 expression in living organisms. Combination therapy involving anti-PD-1 treatment and Alisertib significantly prolonged overall survival compared to vehicle treatment. These findings suggest that targeting AURKA could have therapeutic implications for modulating the immune environment within GBM cells.

Hsa_circRNA_007630 knockdown delays colon cancer progression by modulation of ferroptosis via miR-506-3p/AURKA axis.

Colon cancer contributes to high mortality rates internationally that has seriously endangered human health. Aurora kinase A (AURKA) served as a key molecule in colon cancer. However, its role of AURKA on regulating ferroptosis in colon cancer and their possible interactions with miRNAs and circRNAs remain still elusive. Comprehensive bioinformatics analysis after RNA-sequencing was conducted to determine the differentially expressed genes (DEGs), ferroptosis-related DEGs and hub genes. The direct relationship between miR-506-3p and hsa_circRNA_007630 or AURKA was predicted, then verified by dual luciferase reporter and quantitative real-time polymerase chain reaction. The rescue experiments were conducted by cotransfection with si-hsa_circRNA_007630, miR-506-3p inhibitor or pcDNA-AURKA in HT29 cells. Erastin was used to induce ferroptosis in HT29 cells and validated by detecting levels of intracellular Fe2+, lipid reactive oxygen species, glutathione, malondialdehyde and ferroptosis markers expression. We screened a total of 331 DEGs, 26 ferroptosis-related genes, among which 3 hub genes were identified through PPI network analysis. Therein, AURKA expression was elevated in colon cancer cells. Moreover, AURKA was targeted by miR-506-3p, and hsa_circRNA_007630 operated as miR-506-3p sponge. The effect of hsa_circRNA_007630 depletion on the inhibiting malignant phenotypes of HT29 cells was rescued by inhibition of miR-506-3p or AURKA overexpression. Additionally, AURKA reduced erastin-induced ferroptosis in HT29 cells. Depletion of circRNA_007630 exerts as a suppressive role in colon cancer through a novel miR-506-3p/AURKA pathway related to ferroptosis, and might become a novel marker for colon cancer.

Involvement of Endolysosomes and Aurora Kinase A in the Regulation of Amyloid ß Protein Levels in Neurons.

Aurora kinase A (AURKA) is a serine/threonine-protein kinase that regulates microtubule organization during neuron migration and neurite formation. Decreased activity of AURKA was found in Alzheimer's disease (AD) brain samples, but little is known about the role of AURKA in AD pathogenesis. Here, we demonstrate that AURKA is expressed in primary cultured rat neurons, neurons from adult mouse brains, and neurons in postmortem human AD brains. AURKA phosphorylation, which positively correlates with its activity, is reduced in human AD brains. In SH-SY5Y cells, pharmacological activation of AURKA increased AURKA phosphorylation, acidified endolysosomes, decreased the activity of amyloid beta protein (Aß) generating enzyme ß-site amyloid precursor protein cleaving enzyme (BACE-1), increased the activity of the Aß degrading enzyme cathepsin D, and decreased the intracellular and secreted levels of Aß. Conversely, pharmacological inhibition of AURKA decreased AURKA phosphorylation, de-acidified endolysosomes, decreased the activity of cathepsin D, and increased intracellular and secreted levels of Aß. Thus, reduced AURKA activity in AD may contribute to the development of intraneuronal accumulations of Aß and extracellular amyloid plaque formation.

Understanding the Differences of Danusertib's Residence Time in Aurora Kinases A/B: Dissociation Paths and Key Residues Identified using Conventional and Enhanced Molecular Dynamics Simulations.

The accurate experimental estimation of protein-ligand systems' residence time (τ) has become very relevant in drug design projects due to its importance in the last stages of refinement of the drug's pharmacodynamics and pharmacokinetics. It is now well-known that it is not sufficient to estimate the affinity of a protein-drug complex in the thermodynamic equilibrium process in in vitro experiments (closed systems), where the concentrations of the drug and protein remain constant. On the contrary, it is mandatory to consider the conformational dynamics of the system in terms of the binding and unbinding processes between protein and drugs in in vivo experiments (open systems), where their concentrations are in constant flux. This last model has been proven to dictate much of several drugs' pharmacological activities in vivo. At the atomistic level, molecular dynamics simulations can explain why some drugs are more effective than others or unveil the molecular aspects that make some drugs work better in one molecular target. Here, the protein kinases Aurora A/B, complexed with its inhibitor Danusertib, were studied using conventional and enhanced molecular dynamics (MD) simulations to estimate the dissociation paths and, therefore, the computational τ values and their comparison with experimental ones. Using classical molecular dynamics (cMD), three differential residues within the Aurora A/B active site, which seems to play an essential role in the observed experimental Danusertib's residence time against these kinases, were characterized. Then, using WT-MetaD, the relative Danusertib's residence times against Aurora A/B kinases were measured in a nanosecond time scale and were compared to those τ values observed experimentally. In addition, the potential dissociation paths of Danusertib in Aurora A and B were characterized, and differences that might be explained by the differential residues in the enzyme's active sites were found. In perspective, it is expected that this computational protocol can be applied to other protein-ligand complexes to understand, at the molecular level, the differences in residence times and amino acids that may contribute to it.

Aurkin-A, a TPX2-Aurora A small molecule inhibitor disrupts Alisertib-induced polyploidy in aggressive diffuse large B cell lymphoma.

Chemotherapy induced polyploidy is a mechanism of inherited drug resistance resulting in an aggressive disease course in cancer patients. Alisertib, an Aurora Kinase A (AK-A) ATP site inhibitor, induces cell cycle disruption resulting in polyaneuploidy in Diffuse Large B Cell Lymphoma (DLBCL). Propidium iodide flow cytometry was utilized to quantify alisertib induced polyploidy in U2932 and VAL cell lines. In U2932 cells, 1µM alisertib generated 8n+ polyploidy in 48% of the total cell population after 5 days of treatment. Combination of Aurkin A an AK-A/TPX2 site inhibitor, plus alisertib disrupted alisertib induced polyploidy in a dose-dependent manner with associated increased apoptosis. We generated a stable FUCCI U2932 cell line expressing Geminin-clover (S/G2/M) and cdt1-mKO (G1), to monitor cell cycle progression. Using this system, we identified alisertib induces polyploidy through endomitosis, which was eliminated with Aurkin A treatment. In a VAL mouse xenograft model, we show polyploidy generation in alisertib treated mice versus vehicle control or Aurkin A. Aurkin A plus alisertib significantly reduced polyploidy to vehicle control levels. Our in vitro and in vivo studies show that Aurkin A synergizes with alisertib and significantly decreases the alisertib dose needed to disrupt polyploidy while increasing apoptosis in DLBCL cells.

Research progress on the relationship between AURKA and tumorigenesis: the neglected nuclear function of AURKA.

AURKA is a threonine or serine kinase that needs to be activated by TPX2, Bora and other factors. AURKA is located on chromosome 20 and is amplified or overexpressed in many human cancers, such as breast cancer. AURKA regulates some basic cellular processes, and this regulation is realized via the phosphorylation of downstream substrates. AURKA can function in either the cytoplasm or the nucleus. It can promote the transcription and expression of oncogenes together with other transcription factors in the nucleus, including FoxM1, C-Myc, and NF-κB. In addition, it also sustains carcinogenic signaling, such as N-Myc and Wnt signaling. This article will focus on the role of AURKA in the nucleus and its carcinogenic characteristics that are independent of its kinase activity to provide a theoretical explanation for mechanisms of resistance to kinase inhibitors and a reference for future research on targeted inhibitors.

AURKA plays an important role in the control of the proliferation, invasion, cell cycle regulation and self-renewal of cancer stem cells.Small molecule kinase inhibitors targeting AURKA have been developed, but the overall response rate of patients in clinical trials is not ideal, prompting us to pay attention to the non-kinase activity of AURKA.This review focuses on the nuclear function of AURKA and its oncogenic properties independent of kinase activity, demonstrating that the nuclear substrate of AURKA and the remote allosteric site of the kinase may be targets of anticancer therapy.

SOX9 is regulated by AURKA in response to Helicobacter pylori infection via EIF4E-mediated cap-dependent translation.

Helicobacter pylori (H. pylori) infection is the main risk factor for gastric cancer. The SRY-Box Transcription Factor 9 (SOX9) serves as a marker of stomach stem cells. We detected strong associations between AURKA and SOX9 expression levels in gastric cancers. Utilizing in vitro and in vivo mouse models, we demonstrated that H. pylori infection induced elevated levels of both AURKA and SOX9 proteins. Notably, the SOX9 protein and transcription activity levels were dependent on AURKA expression. AURKA knockdown led to a reduction in the number and size of gastric gland organoids. Conditional knockout of AURKA in mice resulted in a decrease in SOX9 baseline level in AURKA-knockout gastric glands, accompanied by diminished SOX9 induction following H. pylori infection. We found an AURKA-dependent increase in EIF4E and cap-dependent translation with an AURKA-EIF4E-dependent increase in SOX9 polysomal RNA levels. Immunoprecipitation assays demonstrated binding of AURKA to EIF4E with a decrease in EIF4E ubiquitination. Immunohistochemistry analysis on tissue arrays revealed moderate to strong immunostaining of AURKA and SOX9 with a significant correlation in gastric cancer tissues. These findings elucidate the mechanistic role of AURKA in regulating SOX9 levels via cap-dependent translation in response to H. pylori infection in gastric tumorigenesis.

Primary cilia suppress the fibrotic activity of atrial fibroblasts from patients with atrial fibrillation in vitro.

Atrial fibrosis serves as an arrhythmogenic substrate in atrial fibrillation (AF) and contributes to AF persistence. Treating atrial fibrosis is challenging because atrial fibroblast activity is multifactorial. We hypothesized that the primary cilium regulates the profibrotic response of AF atrial fibroblasts, and explored therapeutic potentials of targeting primary cilia to treat fibrosis in AF. We included 25 patients without AF (non-AF) and 26 persistent AF patients (AF). Immunohistochemistry using a subset of the patients (non-AF: n = 10, AF: n = 10) showed less ciliated fibroblasts in AF versus non-AF. Acetylated α-tubulin protein levels were decreased in AF, while the gene expressions of AURKA and NEDD9 were highly increased in AF patients' left atrium. Loss of primary cilia in human atrial fibroblasts through IFT88 knockdown enhanced expression of ECM genes, including FN1 and COL1A1. Remarkably, restoration or elongation of primary cilia by an AURKA selective inhibitor or lithium chloride, respectively, prevented the increased expression of ECM genes induced by different profibrotic cytokines in atrial fibroblasts of AF patients. Our data reveal a novel mechanism underlying fibrotic substrate formation via primary cilia loss in AF atrial fibroblasts and suggest a therapeutic potential for abrogating atrial fibrosis by restoring primary cilia.

Combination of an aurora kinase inhibitor and the ABL tyrosine kinase inhibitor asciminib against ABL inhibitor-resistant CML cells.

The development of BCR::ABL1-targeting tyrosine kinase inhibitors (TKIs) has improved the prognosis of patients with chronic myeloid leukemia (CML). However, resistance to ABL TKIs can develop in CML patients due to BCR::ABL1 point mutations and CML leukemia stem cell (LSC). Aurora kinases are essential kinases for cell division and regulate mitosis, especially the process of chromosomal segregation. Aurora kinase members also promote cancer cell survival and proliferation. This study analyzed whether aurora kinases were regulated in the progression of CML. It also evaluated the efficacy of the ABL TKI asciminib and the aurora kinase inhibitor LY3295668. The expressions of AURKA and AURKB were higher in the CML cells compared with normal cells using a public database (GSE100026). Asciminib or LY3295668 alone inhibited CML cells after 72 h, and cellular cytotoxicity was increased. The combined use of Asciminib and LY3295668 increased superior efficacy compared with either drug alone. Colony formation was reduced by cotreatment with asciminib and LY3295668. In the cell-cycle analyses, LY3295668 induced G2/M arrest. Cell populations in the sub-G1 phase were observed when cotreating with asciminib and LY3295668. The combination treatment also changed the mitochondrial membrane potential. In addition, AURKA shRNA transfectant cells had increased asciminib sensitivity. Combining asciminib and aurora kinase inhibition enhanced the efficacy and is proposed as a new therapeutic option for patients with CML. These findings have clinical implications for a potential novel therapeutic strategy for CML patients.

Targeting AURKA to induce synthetic lethality in CREBBP-deficient B-cell malignancies via attenuation of MYC expression.

Loss-of-function mutations in CREBBP, which encodes for a histone acetyltransferase, occur frequently in B-cell malignancies, highlighting CREBBP deficiency as an attractive therapeutic target. Using established isogenic cell models, we demonstrated that CREBBP-deficient cells are selectively vulnerable to AURKA inhibition. Mechanistically, we found that co-targeting CREBBP and AURKA suppressed MYC transcriptionally and post-translationally to induce replication stress and apoptosis. Inhibition of AURKA dramatically decreased MYC protein level in CREBBP-deficient cells, implying a dependency on AURKA to sustain MYC stability. Furthermore, in vivo studies showed that pharmacological inhibition of AURKA was efficacious in delaying tumor progression in CREBBP-deficient cells and was synergistic with CREBBP inhibitors in CREBBP-proficient cells. Our study sheds light on a novel synthetic lethal interaction between CREBBP and AURKA, indicating that targeting AURKA represents a potential therapeutic strategy for high-risk B-cell malignancies harboring CREBBP inactivating mutations.

Multiple intersecting pathways are involved in CPEB1 phosphorylation and regulation of translation during mouse oocyte meiosis.

The RNA-binding protein cytoplasmic polyadenylation element binding 1 (CPEB1) plays a fundamental role in regulating mRNA translation in oocytes. However, the specifics of how and which protein kinase cascades modulate CPEB1 activity are still controversial. Using genetic and pharmacological tools, and detailed time courses, we have re-evaluated the relationship between CPEB1 phosphorylation and translation activation during mouse oocyte maturation. We show that both the CDK1/MAPK and AURKA/PLK1 pathways converge on CPEB1 phosphorylation during prometaphase of meiosis I. Only inactivation of the CDK1/MAPK pathway disrupts translation, whereas inactivation of either pathway alone leads to CPEB1 stabilization. However, CPEB1 stabilization induced by inactivation of the AURKA/PLK1 pathway does not affect translation, indicating that destabilization and/or degradation is not linked to translational activation. The accumulation of endogenous CCNB1 protein closely recapitulates the translation data that use an exogenous template. These findings support the overarching hypothesis that the activation of translation during prometaphase in mouse oocytes relies on a CDK1/MAPK-dependent CPEB1 phosphorylation, and that translational activation precedes CPEB1 destabilization.

Securinine inhibits carcinogenesis in gastric cancer by targeting AURKA-ß-catenin/Akt/STAT3 and the cell cycle pathway.

BACKGROUND: Gastric cancer (GC) is difficult to treat with currently available treatments. Securinine (SCR) has a lengthy history of use in the treatment of disorders of the nervous system, and its anticancer potential has been gaining attention in recent years. The aim of this study was to explore the repressive effect of SCR on GC and its fundamental mechanism. METHODS: The efficacy of SCR in GC cells was detected by MTT assays. Colony formation, flow cytometry and Transwell assays were used to assess the changes in the proliferation, apoptosis, cell cycle distribution, migration and invasion of GC cells after treatment. AGS (human gastric carcinoma cell)-derived xenografts were used to observe the effect of SCR on tumor growth in vivo. The molecular mechanism of action of SCR in GC was explored via RNA sequencing, bioinformatics analysis, Western blotting, molecular docking, and immunohistochemistry. RESULTS: SCR was first discovered to inhibit the proliferation, migration, and invasion of GC cells while initiating apoptosis and cell cycle arrest in vitro. It was also established that SCR has excellent anticancer effects in vivo. Interestingly, AURKA acts as a crucial target of SCR, and AURKA expression can be blocked by SCR. Moreover, this study revealed that SCR suppresses the cell cycle and the ß-catenin/Akt/STAT3 pathways, which were previously reported to be regulated by AURKA. CONCLUSION: SCR exerts a notable anticancer effect on GC by targeting AURKA and blocking the cell cycle and ß-catenin/Akt/STAT3 pathway. Thus, SCR is a promising pharmacological option for the treatment of GC.

Tabersonine enhances cisplatin sensitivity by modulating Aurora kinase A and suppressing epithelial-mesenchymal transition in triple-negative breast cancer.

CONTEXT: Tabersonine has been investigated for its role in modulating inflammation-associated pathways in various diseases. However, its regulatory effects on triple-negative breast cancer (TNBC) have not yet been fully elucidated. OBJECTIVE: This study uncovers the anticancer properties of tabersonine in TNBC cells, elucidating its role in enhancing chemosensitivity to cisplatin (CDDP). MATERIALS AND METHODS: After tabersonine (10 µM) and/or CDDP (10 µM) treatment for 48 h in BT549 and MDA-MB-231 cells, cell proliferation was evaluated using the cell counting kit-8 and colony formation assays. Quantitative proteomics, online prediction tools and molecular docking analyses were used to identify potential downstream targets of tabersonine. Transwell and wound-healing assays and Western blot analysis were used to assess epithelial-mesenchymal transition (EMT) phenotypes. RESULTS: Tabersonine demonstrated inhibitory effects on TNBC cells, with IC50 values at 48 h being 18.1 µM for BT549 and 27.0 µM for MDA-MB-231. The combined treatment of CDDP and tabersonine synergistically suppressed cell proliferation in BT549 and MDA-MB-231 cells. Enrichment analysis revealed that the proteins differentially regulated by tabersonine were involved in EMT-related signalling pathways. This combination treatment also effectively restricted EMT-related phenotypes. Through the integration of online target prediction and proteomic analysis, Aurora kinase A (AURKA) was identified as a potential downstream target of tabersonine. AURKA expression was reduced in TNBC cells post-treatment with tabersonine. DISCUSSION AND CONCLUSIONS: Tabersonine significantly enhances the chemosensitivity of CDDP in TNBC cells, underscoring its potential as a promising therapeutic agent for TNBC treatment.

PFDN4 as a Prognostic Marker Was Associated with Chemotherapy Resistance through CREBP1/AURKA Pathway in Triple-Negative Breast Cancer.

Breast cancer is the most common malignancy and its incidence is increasing. It is currently mainly treated by clinical chemotherapy, but chemoresistance remains poorly understood. Prefolded proteins 4 (PFDN4) are molecular chaperone complexes that bind to newly synthesized polypeptides and allow them to fold correctly to stabilize protein formation. This study aimed to investigate the role of PFDN4 in chemotherapy resistance in breast cancer. Our study found that PFDN4 was highly expressed in breast cancer compared to normal tissues and was statistically significantly associated with stage, nodal status, subclasses (luminal, HER2 positive and triple negative), triple-negative subtype and disease-specific survival by TCGA database analysis. CRISPR knockout of PFDN4 inhibited the growth of 89% of breast cancer cell lines, and the triple-negative cell line exhibited a stronger inhibitory effect than the non-triple-negative cell line. High PFDN4 expression was associated with poor overall survival in chemotherapy and resistance to doxorubicin and paclitaxel through the CREBP1/AURKA pathway in the triple-negative MDAMB231 cell line. This study provides insightful evidence for the value of PFDN4 in poor prognosis and chemotherapy resistance in breast cancer patients.

Meningioma achieves malignancy and erastin-induced ferroptosis resistance through FOXM1-AURKA-NRF2 axis.

The oncogene Aurora kinase A (AURKA) has been implicated in various tumor, yet its role in meningioma remains unexplored. Recent studies have suggested a potential link between AURKA and ferroptosis, although the underlying mechanisms are unclear. This study presented evidence of AURKA upregulation in high grade meningioma and its ability to enhance malignant characteristics. We identified AURKA as a suppressor of erastin-induced ferroptosis in meningioma. Mechanistically, AURKA directly interacted with and phosphorylated kelch-like ECH-associated protein 1 (KEAP1), thereby activating nuclear factor erythroid 2 related factor 2 (NFE2L2/NRF2) and target genes transcription. Additionally, forkhead box protein M1 (FOXM1) facilitated the transcription of AURKA. Suppression of AURKA, in conjunction with erastin, yields significant enhancements in the prognosis of a murine model of meningioma. Our study elucidates an unidentified mechanism by which AURKA governs ferroptosis, and strongly suggests that the combination of AURKA inhibition and ferroptosis-inducing agents could potentially provide therapeutic benefits for meningioma treatment.

Synergy of EGFR and AURKA Inhibitors in KRAS-mutated Non-small Cell Lung Cancers.

The most common oncogenic driver mutations for non-small cell lung cancer (NSCLC) activate EGFR or KRAS. Clinical trials exploring treatments for EGFR- or KRAS-mutated (EGFRmut or KRASmut) cancers have focused on small-molecule inhibitors targeting the driver mutations. Typically, these inhibitors perform more effectively based on combination with either chemotherapies, or other targeted therapies. For EGFRmut NSCLC, a combination of inhibitors of EGFR and Aurora-A kinase (AURKA), an oncogene commonly overexpressed in solid tumors, has shown promising activity in clinical trials. Interestingly, a number of recent studies have indicated that EGFR activity supports overall viability of tumors lacking EGFR mutations, and AURKA expression is abundant in KRASmut cell lines. In this study, we have evaluated dual inhibition of EGFR and AURKA in KRASmut NSCLC models. These data demonstrate synergy between the EGFR inhibitor erlotinib and the AURKA inhibitor alisertib in reducing cell viability and clonogenic capacity in vitro, associated with reduced activity of EGFR pathway effectors, accumulation of enhanced aneuploid cell populations, and elevated cell death. Importantly, the erlotinib-alisertib combination also synergistically reduces xenograft growth in vivo. Analysis of signaling pathways demonstrated that the combination of erlotinib and alisertib was more effective than single-agent treatments at reducing activity of EGFR and pathway effectors following either brief or extended administration of the drugs. In sum, this study indicates value of inhibiting EGFR in KRASmut NSCLC, and suggests the specific value of dual inhibition of AURKA and EGFR in these tumors. SIGNIFICANCE: The introduction of specific KRAS G12C inhibitors to the clinical practice in lung cancer has opened up opportunities that did not exist before. However, G12C alterations are only a subtype of all KRAS mutations observed. Given the high expression of AURKA in KRASmut NSCLC, our study could point to a potential therapeutic option for this subgroup of patients.

Identification of AURKA as a Biomarker Associated with Cuproptosis and Ferroptosis in HNSCC.

Cuproptosis and ferroptosis represent copper- and iron-dependent forms of cell death, respectively, and both are known to play pivotal roles in head and neck squamous cell carcinoma (HNSCC). However, few studies have explored the prognostic signatures related to cuproptosis and ferroptosis in HNSCC. Our objective was to construct a prognostic model based on genes associated with cuproptosis and ferroptosis. We randomly assigned 502 HSNCC samples from The Cancer Genome Atlas (TCGA) into training and testing sets. Pearson correlation analysis was utilized to identify cuproptosis-associated ferroptosis genes in the training set. Cox proportional hazards (COX) regression and least absolute shrinkage operator (LASSO) were employed to construct the prognostic model. The performance of the prognostic model was internally validated using single-factor COX regression, multifactor COX regression, Kaplan-Meier analysis, principal component analysis (PCA), and receiver operating curve (ROC) analysis. Additionally, we obtained 97 samples from the Gene Expression Omnibus (GEO) database for external validation. The constructed model, based on 12 cuproptosis-associated ferroptosis genes, proved to be an independent predictor of HNSCC prognosis. Among these genes, the increased expression of aurora kinase A (AURKA) has been implicated in various cancers. To further investigate, we employed small interfering RNAs (siRNAs) to knock down AURKA expression and conducted functional experiments. The results demonstrated that AURKA knockdown significantly inhibited the proliferation and migration of HNSCC cells (Cal27 and CNE2). Therefore, AURKA may serve as a potential biomarker in HNSCC.

Discovery of a Long Half-Life AURKA Inhibitor to Treat MYC-Amplified Solid Tumors as a Monotherapy and in Combination with Everolimus.

Aurora kinase inhibitors, such as alisertib, can destabilize MYC-family oncoproteins and have demonstrated compelling antitumor efficacy. In this study, we report 6K465, a novel pyrimidine-based Aurora A inhibitor, that reduces levels of c-MYC and N-MYC oncoproteins more potently than alisertib. In an analysis of the antiproliferative effect of 6K465, the sensitivities of small cell lung cancer (SCLC) and breast cancer cell lines to 6K465 were strongly associated with the protein levels of c-MYC and/or N-MYC. We also report DBPR728, an acyl-based prodrug of 6K465 bearing fewer hydrogen-bond donors, that exhibited 10-fold improved oral bioavailability. DBPR728 induced durable tumor regression of c-MYC- and/or N-MYC-overexpressing xenografts including SCLC, triple-negative breast cancer, hepatocellular carcinoma, and medulloblastoma using a 5-on-2-off or once-a-week dosing regimen on a 21-day cycle. A single oral dose of DBPR728 at 300 mg/kg induced c-MYC reduction and cell apoptosis in the tumor xenografts for more than 7 days. The inhibitory effect of DBPR728 at a reduced dosing frequency was attributed to its uniquely high tumor/plasma ratio (3.6-fold within 7 days) and the long tumor half-life of active moiety 6K465. Furthermore, DBPR728 was found to synergize with the mTOR inhibitor everolimus to suppress c-MYC- or N-MYC-driven SCLC. Collectively, these results suggest DBPR728 has the potential to treat cancers overexpressing c-MYC and/or N-MYC.