Expression Of Aurora Kinase B Research Articles

AURKB promotes bladder cancer progression by deregulating the p53 DNA damage response pathway via MAD2L2

BackgroundBladder cancer (BC) is the most common urinary tract malignancy. Aurora kinase B (AURKB), a component of the chromosomal passenger protein complex, affects chromosomal segregation during cell division. Mitotic arrest-deficient 2-like protein 2 (MAD2L2) interacts with various proteins and contributes to genomic integrity. Both AURKB and MAD2L2 are overexpressed in various human cancers and have synergistic oncogenic effects; therefore, they are regarded as emerging therapeutic targets for cancer. However, the relationship between these factors and the mechanisms underlying their oncogenic activity in BC remains largely unknown. The present study aimed to explore the interactions between AURKB and MAD2L2 and how they affect BC progression via the DNA damage response (DDR) pathway.MethodsBioinformatics was used to analyze the expression, prognostic value, and pro-tumoral function of AURKB in patients with BC. CCK-8 assay, colony-forming assay, flow cytometry, SA-β-gal staining, wound healing assay, and transwell chamber experiments were performed to test the viability, cell cycle progression, senescence, and migration and invasion abilities of BC cells in vitro. A nude mouse xenograft assay was performed to test the tumorigenesis ability of BC cells in vivo. The expression and interaction of proteins and the occurrence of the senescence-associated secretory phenotype were detected using western blot analysis, co-immunoprecipitation assay, and RT-qPCR.ResultsAURKB was highly expressed and associated with prognosis in patients with BC. AURKB expression was positively correlated with MAD2L2 expression. We confirmed that AURKB interacts with, and modulates the expression of, MAD2L2 in BC cells. AURKB knockdown suppressed the proliferation, migration, and invasion abilities of, and cell cycle progression in, BC cells, inducing senescence in these cells. The effects of AURKB knockdown were rescued by MAD2L2 overexpression in vitro and in vivo. The effects of MAD2L2 knockdown were similar to those of AURKB knockdown. Furthermore, p53 ablation rescued the MAD2L2 knockdown-induced suppression of BC cell proliferation and cell cycle arrest and senescence in BC cells.ConclusionsAURKB activates MAD2L2 expression to downregulate the p53 DDR pathway, thereby promoting BC progression. Thus, AURKB may serve as a potential molecular marker and a novel anticancer therapeutic target for BC.

Overexpression of Aurora Kinase B Is Correlated with Diagnosis and Poor Prognosis in Hepatocellular Carcinoma.

Aurora kinase B (AURKB) overexpression promotes tumor initiation and development by participating in the cell cycle. In this study, we focused on the mechanism of AURKB in hepatocellular carcinoma (HCC) progression and on AURKB's value as a diagnostic and prognostic biomarker in HCC. We used data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) to analyze AURKB expression in HCC. We found that the expression levels of AURKB in HCC samples were higher than those in the corresponding control group. R packages were used to analyze RNA sequencing data to identify AURKB-related differentially expressed genes (DEGs), and these genes were found to be significantly enriched during the cell cycle. The biological function of AURKB was verified, and the results showed that cell proliferation was slowed down and cells were arrested in the G2/M phase when AURKB was knocked down. AURKB overexpression resulted in significant differences in clinical symptoms, such as the clinical T stage and pathological stage. Kaplan-Meier survival analysis, Cox regression analysis, and Receiver Operating Characteristic (ROC) curve analysis suggested that AURKB overexpression has good diagnostic and prognostic potential in HCC. Therefore, AURKB may be used as a potential target for the diagnosis and cure of HCC.

Aurora kinase B disruption suppresses pathological retinal angiogenesis by affecting cell cycle progression

PurposeThe detrimental effects of pathological angiogenesis on the visual function are indisputable. Within a prominent role in chromosome segregation and tumor progression, aurora kinase B (AURKB) assumes a prominent role. However, its role in pathological retinal angiogenesis remains unclear. This study explores this latent mechanism. MethodsTo inhibit AURKB expression, we designed specific small interfering RNAs targeting AURKB and transfected them into vascular endothelial cells. Barasertib was selected as the AURKB inhibitor. The anti-angiogenic effects of both AURKB siRNA and barasertib were assessed in vitro by cell proliferation, transwell migration, and tube formation. To evaluate the angiogentic effects of AURKB in vivo, neonatal mice were exposed to 75% oxygen followed by normoxic repositioning to establish an oxygen-induced retinopathy (OIR) model. Subsequently, phosphate-buffered saline and barasertib were administered into OIR mice via intravitreal injection. The effects of AURKB on cell cycle proteins were determined by western blot analysis. ResultsWe found that AURKB was overexpressed during pathological angiogenesis. AURKB siRNA and barasertib significantly inhibited endothelial cell proliferation, migration, and tube formation in vitro. Furthermore, AURKB inhibition attenuated retinal angiogenesis in the OIR model. A possible mechanism is the disruption of cell cycle by AURKB inhibition. ConclusionIn conclusion, AURKB significantly influenced pathological retinal angiogenesis, thereby presenting a promising therapeutic target in ocular neovascular diseases.

AURKB Geni miR-34a-5p ve let-7b-5p Tarafından Hedeflendiğinden AML Hücre Proliferasyonunda Rol Oynar mı?

Objective: The production of normal blood cells in the bone marrow is interrupted in AML, which is characterized by the proliferation and accumulation of leukemic blasts. Therefore, patients experience anemia and thrombocytopenia. When gene expression of Aurora kinases, which is reported to be highly expressed in AML, decreases, it may be possible to alleviate the clinical findings in AML. In this study, it was aimed to examine the relationship of AURKB with important miRNAs that have the potential to regulate gene expression. 
 Method: HL60 and NB4 cells were transfected with important tumor suppressor miRNAs miR-34a-5p and let-7b-5p mimics. Then, its effects on proliferation were examined with WST-8 technique and its effects on AURKB gene expression were examined with qRT-PCR.
 Results: It was determined that these miRNAs negatively regulated proliferation in both AML cell lines and downregulated the expression level of the Aurora kinase B (AURKB) gene in the miRNA transfected group compared to the control group.
 Conclusion: In conclusion, it was determined that miR-34a-5p and let-7b-5p could regulate AURKB expression in AML cells. Therefore, it was thought that these miRNAs may have an important potential as a therapeutic biomarker in preventing excessive cell division and poor prognosis in AML.

High expression of aurora kinase B predicts poor prognosis in hepatocellular carcinoma after curative surgery and its effects on the tumor microenvironment.

Currently, the only broadly used biomarker for hepatocellular carcinoma (HCC), alpha fetoprotein (AFP), has multiple limitations and the need for novel biomarkers is urgent. Aurora kinase B (AURKB) is a key mitotic protein kinase which performs a critical function in cell cycle progression. Nonetheless, neither the function nor the mechanism of AURKB in HCC following curative surgery is fully grasped at this time. This study sought to evaluate the impact of AURKB on prognosis and the tumor immune microenvironment (TIME) in HCC. We evaluated both the expression profile of AURKB in HCC and its clinical value using online databases and clinical specimens. The prognostic value of AURKB was studied by Kaplan-Meier survival analysis, and the link between AURKB and tumor-infiltrating immune cells (TIICs) were analyzed. We found the mRNA expression patterns of AURKB were remarkably upregulated in HCC in contrast with adjoining normal tissues (P<0.001). Upregulation of the AURKB protein in HCC was additionally verified by clinical samples. The expression of AURKB was substantially associated with Child-Pugh, microvascular invasion (MVI), Edmondson-Steiner grade, and tumor recurrence. Furthermore, patients diagnosed with HCC who had a low AURKB expression had a better. Our data suggested age [hazard ratio (HR): 1.34], alanine aminotransferase (ALT) (HR: 1.65), tumor size (HR: 1.99), mor number (HR: 1.60), MVI (HR: 1.93), grade (HR: 5.58), and AURKB expression (HR: 3.63) independently functioned as prognostic risk indicators for HCC (P<0.05). Importantly, we also found AURKB expression was inversely linked to resting natural killer (NK) cells, M2 macrophages, activated mast cells, and naive B cells, and positively linked to M0 macrophages, T follicular helper cells (Tfh), regulatory T cells (Treg), and resting myeloid dendritic cells. In addition, AURKB expression was also positively linked to the immune checkpoints of PDCD1, CD274, CTLA4, and LAG3. Finally, 1,696 DEGs were discovered, and were predominantly implicated in chromosome segregation, cell cycle, xenobiotic metabolic process, calcium signaling pathway, bile secretion, tyrosine metabolism, and DNA replication. AURKB may be a potential prognostic biomarker for HCC after curative surgery, which correlates with MVI and the TIME in HCC.

Identification of prognostic genes for early basal-like breast cancer with weighted gene co-expression network analysis.

Background:Breast cancer (BC) has become the leading cause of death for women’s malignancies and increasingly threatens the health of women worldwide. However, there is a lack of effective targeted drugs for basal-like BC. Therefore, biomarkers related to the prognosis of early BC need to be identified.Methods:The RNA-seq data of 87 cases of early basal-like BC and 111 cases of normal breast tissue from The Cancer Genome Atlas were explored by the weighted gene co-expression network analysis method and Limma package. Then, intersected genes were identified, and hub genes were selected by the maximal clique centrality method. The prognostic effect of the hub genes was also evaluated in early basal-like BC.Results:In total, 601 IGs were identified in this study. An APPI network was constructed, and the top 10 hub genes were selected, namely, cyclin B1, cyclin A2, cyclin-dependent kinase 1, cell division cycle 20, DNA topoisomerase II alpha, BUB1 mitotic checkpoint serine/threonine kinase, aurora kinase B (AURKB), cyclin B2, kinesin family member 11, and assembly factor for spindle microtubules. Only AURKB was found to be significantly associated with the overall prognosis of early basal-like BC. The immune cell infiltration analysis showed that the infiltration numbers of CD4 + T cells and naïve CD8 + T cells were positively correlated with the AURKB expression level, while those of naïve B cells and macrophage M2 cells were negatively correlated with the AURKB expression level in basal-like BC.Conclusion:AURKB might be a potential prognostic indicator in early basal-like BC.

Abstract 2015: The Aurora kinases are a potential therapeutic target in Ewing sarcoma

Abstract The poor survival rates and limited treatment options for patients with relapsed/metastatic Ewing sarcoma (ES) highlights the need for more personalized targeted therapeutic approaches. In this project, we have investigated the prognostic potential of Aurora kinase expression in ES patients and evaluated the activity of Aurora kinase inhibitors in ES cell lines and patient derived cultures. The prognostic value of Aurora kinase A (AURKA), Aurora kinase B (AURKB) and Aurora kinase C (AURKC) was determined through interrogation of the online GSE17618 dataset using Cox models and Kaplan Meier plots. RNA seq data was obtained from the CCRG dataset for expression analysis (Roundhill et al., 2021, Cell Oncol, 44(5), 1065-85). Viable cell number was determined using the trypan blue exclusion assay on the Vi-CELL XR. Cells were treated with increasing concentrations of inhibitor (Table 1) or DMSO vehicle control for 48h. Protein was extracted after 48h for western blotting. In ES patients, high RNA expression of AURKA and AURKB is associated with a 5- and 3-fold increased risk of death respectively (n=42). Risk of an event was increased 3- or 2-fold with high expression of AURKA or AURKB respectively (n=42). High AURKC expression was not prognostic. Expression of AURKA and AURKB was confirmed at the RNA level in ES cell lines and patient derived cultures, and at the protein level in cell lines. Aurora kinase inhibitors (Table 1) decreased viable cell number of ES cell lines and patient derived cultures. Western blotting confirmed a decrease in AURKA and MYC-C expression with increasing concentration of inhibitor. AMG900 was the most potent inhibitor in TC32 cells (Table 1) and decreased viable cell number of patient derived cultures (n=5, p&amp;lt;0.01). High expression of AURKA or AURKB mRNA predicts poor outcome for ES patients. Inhibitors of these kinases reduce viable cell number of both ES cell lines and patient derived cultures. We are currently investigating the mechanism of action. Table 1. Summary of the effect of Aurora kinase inhibitors in TC32 ES cells. Aurora Kinase Inhibitor Concentration Range Used (nM) Target Kinases(IC50, nM) EC50 TC32 Cells (nM) (n=3) P value (EC50 AMG900 vs EC50 another inhibitor) References AMG900 1.25-50 AurA (5), AurB (4), AurC (1) + 10 kinases 1.57 N/A Payton et al., 2010, Cancer Res, 70(23), 9846-54 MLN8237 5-300 AurA (1.2), AurB (396.5) + 22 kinases 29.48 0.0468 Manfredi et al., 2011, Clin Cancer Res, 17(24), 7614-24 CCT137690 5-300 AurA (15), AurB (25), AurC (19) + 3 kinases 97.56 0.0004 Bavetsias et al., 2010, J Med Chem, 53(14), 5213-28 LY3295668 31.25-1000 AurA (0.8) AurB (1038)AurC (98) + 2 kinases Not able to calculate N/A Gong et al., 2019, Cancer Discov, 9(2), 248-263 EC50 values were calculated by nonlinear regression (GraphPad PRISM). Statistical differences between EC50 of AMG900 and the EC50 of other inhibitors were evaluated using two-way ANOVA and Tukey’s multiple comparisons test. IC50 - half maximal inhibitory concentration, EC50 - half maximal effective concentration Citation Format: Molly McNae, Elizabeth A. Roundhill, Susan A. Burchill, Richard W. Bayliss. The Aurora kinases are a potential therapeutic target in Ewing sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2015.

Abstract 3251: Aurora kinase B expression shields HNSCC from PI3K inhibition-induced apoptosis through downstream mediators AKT and PDK1

Abstract Effective targeted therapies are lacking for head and neck squamous cell carcinoma (HNSCC) that is common and fatal. Developing targeted therapies for HNSCC is challenging as the genomic landscape is dominated by mutations in tumor suppressors, including NOTCH1. To address this need, we previously demonstrated that PI3K inhibition led to apoptosis in NOTCH1 mutant HNSCC cell lines. The underlying mechanism of this sensitivity is unknown and important to elucidate as modest responses and development of acquired resistance are the leading causes of failure for targeted therapies. To address this knowledge gap, we measured the levels of 304 proteins using reverse phase protein array in NOTCH1WT and NOTCH1MUT HNSCC cell lines upon PI3K inhibition and identified Aurora kinase B (AURKB) to be differentially regulated. We also identified AURKB levels to be maintained in the NOTCH1MUT cell lines with acquired resistance to PI3K inhibition. To determine if the maintenance of AURKB expression contributes to PI3K inhibitor resistance, we depleted AURKB in resistant NOTCH1WT HNSCC cells and overexpressed AURKB in sensitive NOTCH1MUT HNSCC cells. This manipulation of AURKB levels led to increased sensitivity and resistance to PI3K inhibition respectively. To use a pharmacologic approach, we combined the pan-Aurora kinase inhibitor danusertib (0-2µM) with PI3K/mTOR inhibitor omipalisib (0-200nM) in 56 HNSCC cell lines for 72h and observed a substantial decrease in cell viability in &amp;gt;80% of NOTCH1WT and &amp;gt;90% of NOTCH1MUT HNSCC lines. Additionally, concurrent Aurora kinase and PI3K inhibition in NOTCH1WT, NOTCH1MUT, and NOTCH1MUT acquired resistant HNSCC cells for 24h resulted in elevated cell death compared to single agents, as measured by the induction of cleaved PARP and cleaved Caspase 3; and Annexin V positive cells. Mice bearing NOTCH1MUT xenografts showed complete tumor regression when treated with a combination of pan-PI3K inhibitor Copanlisib and Aurora inhibitor Alisertib as compared to control groups. AURKB depletion in NOTCH1WT and overexpression in NOTCH1MUT HNSCC cells revealed significant changes in the total protein levels of AKT and PDK1. Similarly, AKT depletion and overexpression in NOTCH1WT and NOTCH1MUT HNSCC cells altered sensitivity to PI3K inhibition. However, manipulation of AKT levels affected PDK1 and not AURKB levels, demonstrating AURKB to be upstream to AKT and PDK1. Therefore, maintenance of AURKB levels mediates resistance to PI3K inhibition in HNSCC through AKT and PDK1. We identified AURKB as a central player governing the sensitivity to PI3K inhibitor-induced apoptosis in the context of NOTCH1 mutation status in HNSCC through its effects on AKT and PDK1. These novel findings may lead to the development of more robust therapeutic approach for NOTCH1 mutant squamous carcinoma as well as patients who develop acquired resistance to targeted therapies. Citation Format: Pooja A. Shah, Anne M. Fernandez, Vaishnavi Sambandam, Hongyun Zhao, Tuhina Mazumdar, Li Shen, Jing Wang, Faye M. Johnson. Aurora kinase B expression shields HNSCC from PI3K inhibition-induced apoptosis through downstream mediators AKT and PDK1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3251.

The Pivotal Role of Glutaminolysis in Multiple Myeloma: Novel Strategies for Target Therapies Against Myeloma

Introduction:Multiple myeloma (MM) is a uniformly fatal disorder of B cells characterized by the clonal expansion of plasma cells in the bone marrow. The treatment of MM patients has been dramatically changed by new agents such as proteasome inhibitors and immunomodulatory drugs, however, many patients will relapse even if new agents provide therapeutic advantages. Therefore, a new strategy is still needed to increase MM patient survival. Metabolic reprogramming is recognized as one of the hallmarks of cancer cells. Glutamine is the most abundant circulating amino acid in blood, glutamine metabolism through glutaminolysis may be associated with myeloma cell maintenance and survival.Materials and Methods:In this study, we investigated whether glutaminolysis was involved the proliferation in myeloma cells. We also investigated whether glutaminase (GLS) inhibitor, CB-839 could suppress myeloma cells and enhance the sensitivity of myeloma cells to histone deacetylase (HDAC) inhibition.Results:We first investigated the relationship between glutamine transporter or GLS gene expression and MM patients by microarray gene expression data from the online Gene Expression Omnibus (GEO). Glutamine transporter genes such as SLC38A1 and SLC1A5 were increased in myeloma and plasma cell leukemia cells (GSE13591). In contrast, GLS1 expression was not changed. We next investigated the glutaminolysis in myeloma cells. Deprivation of glutamine in culture medium revealed that cellular growth inhibition and cell cycle arrest at G0/G1 phase. Gene expression of AURKA (aurora kinase A), AURKB (aurora kinase B), HSP90AA1 (Heat Shock Protein 90 Alpha Family Class A Member 1) and CCNB1 (cyclin B1) were reduced from the public microarray datasets (GSE59931) and protein expressions were also reduced by immunoblot analysis. We next evaluated the effect of GLS inhibitor, CB-839. 72 h treatment of MM cells were inhibited by CB-839 in a dose dependent manner. Cellular cytotoxicity was also increased. Glutamine is converted by GLS into glutamate and alpha-ketoglutarate (α-KG), and related nicotinamide adenine dinucleotide phosphate (NADP) production. Intracellular α-KG and NADPH were reduced by CB-839. As metabolites are the substrates used to generate chromatin modification including acetylation of histone, we investigated HDAC inhibitor, panobinostat in myeloma cells. 72 h treatment of MM cells were inhibited by panobinostat and histone acetylation was increased. Combined treatment with panobinostat and CB-839 caused more cytotoxicity than each drug alone. Panobinostat and CB-839 also inhibited bortezomib resistant cells. Caspase 3/7 activity and cellular cytotoxicity were also increased. Proteasomal activity was reduced. Adenosine triphosphate (ATP) is the most important source of energy for intracellular reactions. Intracellular ATP levels drastically decreased. Because mitochondria generate ATP and participate in signal transduction and cellular pathology and cell death. The quantitative analysis of JC-1 stained cells changed mitochondrial membrane potential in cell death, which were induced by panobinostat and CB-839 on myeloma cells. Immunoblot analysis revealed that protein expression of aurora kinase A, aurora kinase B, HSP90 and cyclin B1 were reduced, and cleaved caspase 3 and γ- H2AX were increased by panobinostat and CB-839 treatment. GLS shRNA transfectant cells were inhibited cellular proliferation and sub-G1 phase was increased by cell cycle analysis. GLS shRNA transfectant cells were increased the sensitivity of panobinostat compared to control cells.Conclusion:The glutaminolysis is involved myeloma cell proliferation and GLS inhibitor is effective to myeloma cells and enhance cytotoxic effects of HDAC inhibitors. We also provide the promising clinical relevance as a candidate drug for treatment of myeloma patients. DisclosuresNo relevant conflicts of interest to declare.

RNA-binding protein RNPC1 acts as an oncogene in gastric cancer by stabilizing aurora kinase B mRNA

BackgroundRNPC1 is reported to act as a tumor suppressor by binding and regulating the expression of target genes in various cancers. However, the role of RNPC1 in gastric cancer and the underlying mechanisms are still unclear. MethodsGastric cancer cells were stably transfected with lentivirus. Proliferation, migration, invasion, cell cycle in vitro and tumorigenesis in vivo were used to assess the role of RNPC1. Quantitative real-time PCR, western blotting and immunohistochemistry were used to detect the relationship between RNPC1 and aurora kinase B (AURKB). RNA immunoprecipitation (RIP), RNA electrophoretic mobility shift assays (REMSAs), and dual-luciferase reporter assays were used to identify the direct binding sites of RNPC1 with AURKB mRNA. A CCK-8 assay was conducted to confirm the function of AURKB in RNPC1-induced growth promotion. ResultsHigh RNPC1 expression was found in gastric cancer tissues and cell lines and was associated with high TNM stage. RNPC1 overexpression significantly promoted the proliferation, migration, and invasion of gastric cancer cells. Knockdown of RNPC1 could impede gastric cancer tumorigenesis in nude mice. AURKB expression was positively related to RNPC1. RNPC1 directly binds to the 3'-untranslated region (3'-UTR) of AURKB and enhances AURKB mRNA stability. AURKB reversed the proliferation induced by RNPC1 in gastric cancer cells. RNPC1 resulted in mitotic defects, aneuploidy and chromosomal instability in gastric cancer cells, similar to AURKB. ConclusionRNPC1 acts as an oncogene in gastric cancer by influencing cell mitosis by increasing AURKB mRNA stability, which may provide a potential biomarker and a therapeutic target for gastric cancer.

Abstract 2156: Genomics and molecular analysis of Aurora kinase B (AURKB) in response to antiretroviral (ARV) treatment in lung cancer

Abstract Aurora kinase B (AURKB) is essential for normal physiological processes. However, aberrant AURKB expression has been reported in various cancers, including lung cancer. Lung cancer is a leading non-AIDS defining cancer (NADCs) and the relationship between the use of antiretrovirals (ARVs) and lung cancer is poorly understood. The anti-proliferative effects of Efavirenz (EFV) and Lopinavir/ritonavir (LPV/r) have also been documented. This study aimed at determining the genomic and molecular roles of AURKB in lung cancer in response to ARV treatment. For this purpose, cellular (xCELLigence RTCA), molecular (RT-qPCR) and bioinformatics tools were used in normal fibroblasts (MRC-5) and adenocarcinoma (A549) lung cells. Real-Time Cell Analysis (RTCA) data confirmed the anti-proliferative effects of ARVs in a time-dependent manner. AURKB gene expression was elevated in A549 compared to MRC-5 in non-ARV treated. Interestingly, p53 and CASP3 gene expression was downregulated. Contrarily, ARV treatment resulted in the formation of a negative signaling loop due to AURKB being downregulated, while CASP3 and p53 were upregulated. KEGG analysis demonstrated AURKB, CASP3 and p53 as cell cycle related genes. STRING database searches showed a strong protein-protein interaction (PPI) between AURKB and p53, and CAP3 and p53, but a weak PPI between AURKB and CASP3. Gene Ontology (GO) analysis revealed a decline in serine/threonine kinase (AURKB) activity in cancer cells in response to ARV treatment. Although not yet confirmed, AURKB displays oncogene features, while its overexpression has been shown to deregulate p53. The association between the use of ARVs and lung carcinogenesis remains to be fully comprehended and targeting AURKB signaling may help shed light on this relationship. Citation Format: Rahaba Makgotso Marima, Rodney Hull, Zodwa Dlamini, Clement Penny. Genomics and molecular analysis of Aurora kinase B (AURKB) in response to antiretroviral (ARV) treatment in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2156.

Targeting glioma cells by antineoplastic activity of reversine.

Gliomas are the most common type of primary central nervous system tumors and despite great advances in understanding the molecular basis of the disease very few new therapies have been developed. Reversine, a synthetic purine analog, is a multikinase inhibitor that targets aurora kinase A (AURKA) and aurora kinase B (AURKB). In gliomas, a high expression of AURKA or AURKB is associated with a malignant phenotype and a poor prognosis. The present study investigated reversine-related cellular and molecular antiglioma effects in HOG, T98G and U251MG cell lines. Gene and protein expression were assessed by reverse transcription-quantitative PCR and western blotting, respectively. For functional assays, human glioma cell lines (HOG, T98G and U251MG) were exposed to increasing concentrations of reversine (0.4–50 µM) and subjected to various cellular and molecular assays. Reversine reduced the viability and clonogenicity in a dose- and/or time-dependent manner in all glioma cells, with HOG (high AURKB-expression) and T98G (high AURKA-expression) cells being more sensitive compared with U251MG cells (low AURKA- and AURKB-expression). Notably, HOG cells presented higher levels of polyploidy, while T98G presented multiple mitotic spindles, which is consistent with the main regulatory functions of AURKB and AURKA, respectively. In molecular assays, reversine reduced AURKA and/or AURKB expression/activity and increased DNA damage and apoptosis markers, but autophagy-related proteins were not modulated. In conclusion, reversine potently induced mitotic catastrophe and apoptosis in glioma cells and higher basal levels of aurora kinases and genes responsive to DNA damage and may predict improved antiglioma responses to the drug. Reversine may be a potential novel drug in the antineoplastic arsenal against gliomas.

AURKB promotes tumorigenesis and carboplatin resistance by regulating the ERK pathway in neuroblastoma cells

Background Previous research has revealed that activation or aberrant expression of kinases can lead to tumorigenesis of various cancers, including neuroblastoma (NB). Suppression of kinase expression can reduce drug resistance. We explored the potential role and mechanism of the aurora kinase B (AURKB) gene in the acquisition of carboplatin resistance in NB. Methods Immunohistochemistry (IHC) and qRT-PCR were used to explore the AURKB expression in NB patients. Subsequently, we structured Carboplatin-resistant NB cells. The potential biological functions of AURKB in carboplatin resistance were examined through knockdown of AURKB combined with CCK8, flow cytometry, immunohistochemistry, and western blot. Finally, overexpression of AURKB combined with ERK inhibitor (U0126) was carried out to explore the role of downstream signaling pathways. Results Overexpression of AURKB was closely correlated to poor prognosis in NB patients. In vitro, knockdown of AURKB could lead to a decline in IC50 value and restrain the invasion and the expression of MRP1 and Ki67, while promotes apoptosis in carboplatin-resistant cells (IMR-32-R and SK-N-AS-R). Additionally, AURKB overexpression could potentiate the invasion and the expression of MRP1 and Ki67, while suppresses apoptosis in SK-N-AS-R and IMR-32-R, whereas ERK inhibitor U0126 could reverse the phenomenon caused by AURKB overexpression. Conclusion AURKB overexpression was strongly associated with poor prognosis and carboplatin resistant acquisition. Additionally, suppression of AURKB-ERK axis might be a potential therapy for carboplatin resistance in NB patients.

Aurora Kinase B Expression, Its Regulation and Therapeutic Targeting in Human Retinoblastoma.

PurposeAurora kinase B (AURKB) plays a pivotal role in the regulation of mitosis and is gaining prominence as a therapeutic target in cancers; however, the role of AURKB in retinoblastoma (RB) has not been studied. The purpose of this study was to determine if AURKB plays a role in RB, how its expression is regulated, and whether it could be specifically targeted.MethodsThe protein expression of AURKB was determined using immunohistochemistry in human RB patient specimens and immunoblotting in cell lines. Pharmacological inhibition and shRNA-mediated knockdown were used to understand the role of AURKB in cell viability, apoptosis, and cell cycle distribution. Cell viability in response to AURKB inhibition was also assessed in enucleated RB specimens. Immunoblotting was employed to determine the protein levels of phospho-histone H3, p53, p21, and MYCN. Chromatin immunoprecipitation–qPCR was performed to verify the binding of MYCN on the promoter region of AURKB.ResultsThe expression of AURKB was found to be markedly elevated in human RB tissues, and the overexpression significantly correlated with optic nerve and anterior chamber invasion. Targeting AURKB with small-molecule inhibitors and shRNAs resulted in reduced cell survival and increased apoptosis and cell cycle arrest at the G2/M phase. More importantly, primary RB specimens showed decreased cell viability in response to pharmacological AURKB inhibition. Additional studies have demonstrated that the MYCN oncogene regulates the expression of AURKB in RB.ConclusionsAURKB is overexpressed in RB, and targeting it could serve as a novel therapeutic strategy to restrict tumor cell growth.

Inhibition of Aurora Kinase B attenuates fibroblast activation and pulmonary fibrosis.

Fibroblast activation including proliferation, survival, and ECM production is central to initiation and maintenance of fibrotic lesions in idiopathic pulmonary fibrosis (IPF). However, druggable molecules that target fibroblast activation remain limited. In this study, we show that multiple pro‐fibrotic growth factors, including TGFα, CTGF, and IGF1, increase aurora kinase B (AURKB) expression and activity in fibroblasts. Mechanistically, we demonstrate that Wilms tumor 1 (WT1) is a key transcription factor that mediates TGFα‐driven AURKB upregulation in fibroblasts. Importantly, we found that inhibition of AURKB expression or activity is sufficient to attenuate fibroblast activation. We show that fibrosis induced by TGFα is highly dependent on AURKB expression and treating TGFα mice with barasertib, an AURKB inhibitor, reverses fibroblast activation, and pulmonary fibrosis. Barasertib similarly attenuated fibrosis in the bleomycin model of pulmonary fibrosis. Together, our preclinical studies provide important proof‐of‐concept that demonstrate barasertib as a possible intervention therapy for IPF.

AURKB Promotes the Metastasis of Gastric Cancer, Possibly by Inducing EMT.

AimTo investigate the function of Aurora kinase B (AURKB) in gastric cancer (GC).MethodsImmunohistochemistry was used to assay the expression of AURKB in 50 pairs of GC and adjacent tissues, and qRT-PCR was conducted to test AURKB expression in normal gastric epithelial and GC cell lines. Two segments of small interference RNAs (siRNAs) targeting AURKB were synthesized and inserted into GV248 lentivirus vector. After transfected with LV-AURKB-RNAis, CCK8, wound healing, transwell and flow cytometric assays were performed to determine the influence of silencing AURKB on cell proliferation, invasion, migration, cell cycles and apoptosis of GC cells, and the expression of EMT (epithelial–mesenchymal transition)-related markers was demonstrated by Western blots (WB).ResultsAURKB was highly expressed in GC and closely associated with lymph node metastasis and advanced stages of GC. Down-regulating AURKB suppressed the proliferation and promoted the apoptosis of GC cells, arrested the cell cycle in G2/M phase, and inhibited the invasion and migration of GC cells. The expression levels of AKT1, mTOR, Myc, MMP2, and VEGFA were decreased, while the expression levels of OCLN and JUP were increased after knocking down of AURKB in both AGC and MKN45 cells.ConclusionAURKB is overexpressed in GC and closely associated with clinicopathologic characteristics of GC. It is likely that by inhibiting VEGFA/Akt/mTOR and Wnt/β-catenin/Myc pathways, silenced AURKB could inhibit the invasive and migratory abilities of GC cells. However, because of the small sample size and the absence of in-vivo experiments, these results should be verified by further studies.

Abstract B065: Polo-like kinase 1 (PLK1) and aurora kinase B (AURKB) collude with survivin to augment tumor cell proliferation in African-American TNBC: Implications for racial disparity

Abstract Mitotic kinases such as polo-like kinase 1 (PLK1) and aurora kinase B (AURKB) are known to phosphorylate survivin, an IAP family member, to mediate cell survival and proliferation. Interestingly, the triad is significantly overexpressed in multiple tumors including triple-negative breast cancer (TNBC), an aggressive breast cancer subtype, associated with high proliferative capacity, propensity for distant metastasis and therapeutic resistance. Not only TNBCs disproportionately afflict African-American (AA) women compared to European-American (EA) women, AAs demonstrate a much more aggressive disease course compared to their EA counterparts. Largely, most efforts on examining molecular underpinnings of breast cancer-related racial disparity have so far focused on differences in gene expression, epigenetic aspects, and single-nucleotide polymorphisms (SNPs) in tumor tissues. Herein, employing racially distinct TNBC cells, we illuminate the role of survivin phosphorylation, an important post-translational modification, in dictating enhanced cell proliferation and survival in AA TNBC cells compared to EA TNBC cells. Using the publically-available TCGA dataset, our comprehensive in silico analysis of various mitotic and cyclin-dependent kinases yielded a significantly higher gene expression of PLK1 (p=0.061) and AURKB (p=0.003) in AA (n=41) compared to EA TNBC (n=86) patients. Surprisingly, we found no race-related differences in survivin gene expression in TCGA breast dataset (n=127, p=0.343). In addition, there was no statistical difference in survivin protein levels as shown by immunohistochemical staining of survivin in TNBC samples (n=142, p=0.45) from Emory Hospital, Atlanta. Based on these intriguing findings, we hypothesized that the differential functional activity of survivin in AA vs EA TNBC cells augments tumor proliferation in AA TNBC cells. Literature suggests that phosphorylation of survivin at Ser-20 and Thr-117 plays a role in the activity of the chromosome passenger complex (CPC) facilitating mitosis and cell proliferation. We observed an upregulation of phosphorylated substrates of PLK1 and AURKB, namely, p-survivin [Ser-20] and p-survivin [Thr-117], respectively, in AA compared to EA TNBC cell lines. Since most proteins are regulated post-translationally to perform diverse activities, we next knocked down survivin expression in AA, and EA TNBC cell lines, using a siRNA approach. Survivin ablation significantly attenuated cell proliferation, cell cycle progression, but not invasion, and migration in AA TNBC cells compared to EA TNBC cells. These data strongly support our premise that higher functional activity of survivin confers enhanced proliferative capacity on AA TNBC cells compared to EA TNBC cells, suggesting that survivin may be a viable therapeutic target for AA TNBC patients. Further studies intended to tease out the role of survivin phosphorylation in TNBC-related racial disparity are currently under way in our lab. Citation Format: Chakravarthy Garlapati, Shriya Joshi, Rida Padmashree, Ritu Aneja. Polo-like kinase 1 (PLK1) and aurora kinase B (AURKB) collude with survivin to augment tumor cell proliferation in African-American TNBC: Implications for racial disparity [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B065.

AURKB promotes gastric cancer progression via activation of CCND1 expression.

Aurora kinase B (AURKB) triggers the phosphorylation of serine 10 on histone H3 (H3S10ph), which is important for chromosome condensation and cytokinesis during mitosis in mammals. However, how exactly AURKB controls cell cycle and contributes to tumorigenesis as an oncoprotein under pathological conditions remains largely unknown. Here, we report that AURKB promotes gastric cancer cell proliferation in vitro and in vivo. Silencing AURKB expression inhibits gastric cell proliferation and arrests the cell cycle in G2/M phase. We demonstrate that cyclin D1 (CCND1) is a direct downstream target of AURKB that plays a key role in gastric cancer cell proliferation. AURKB is able to activate the expression of CCND1 through mediating H3S10ph in the promoter of the CCND1 gene. Furthermore, we show that AZD1152, a specific inhibitor of AURKB, can suppress the expression of CCND1 in the gastric cancer cells and inhibit cell proliferation in vitro and in vivo. Importantly, we found that high AURKB and CCND1 expression levels are correlated with shorter overall survival of gastric cancer patients. This study demonstrates that AURKB promotes gastric tumorigenesis potentially through epigenetically activating CCND1 expression, suggesting AURKB as a promising therapeutic target in gastric cancer.

High aurora kinase expression identifies patients with muscle-invasive bladder cancer who have poor survival after neoadjuvant chemotherapy

ObjectivesOverexpression of aurora kinase A (AURKA) confers a poor prognosis in patients with urothelial carcinoma of the bladder. The prognostic value of high aurora kinase B (AURKB) expression in local bladder cancer is not well defined, and whether the prognostic value of either AURKA or AURKB is affected by the use of chemotherapy is unknown. We sought to characterize the impact of high AURKA and AURKB expression on clinical outcome in patients with muscle-invasive bladder cancer (MIBC) who received neoadjuvant chemotherapy (NAC). Materials and methodsImmunohistochemistry for AURKA and AURKB was performed on pretreatment diagnostic transurethral resection of bladder tumor (TURBT) and matched cystectomy specimens in 50 subjects with MIBC who received NAC. Receiver operator characteristic curves (ROC) were calculated to assess the impact of AURKA and AURKB expression on pathologic response rate. Kaplan-Meier techniques and Cox proportional hazards models were used to assess the association with relapse-free survival (RFS) and overall survival (OS). ResultsTwenty-two of 50 [44%] patients had residual muscle-invasive (ypT2-4) urothelial carcinoma after NAC. Neither baseline tumor expression of AURKA (ROC = 0.57, P = 0.46) nor AURKB (ROC = 0.56, P = 0.87) predicted for ypT2-4 status. However, baseline expression of AURKA above the 75th percentile for this cohort was associated with an inferior RFS, (HR = 3.88, P = 0.008) and OS, (HR = 6.10, P < 0.001). Similar trends for worse survival outcomes were also observed for high AURKB levels (RFS, [HR = 2.2, P = 0.13] and OS, (HR = 2.25, P = 0.09). ConclusionsHigh baseline tumor AURKA and AURKB expression identified MIBC patients with inferior RFS and OS despite the use of NAC and may identify patients who should be prioritized for clinical trial enrollment rather than standard cisplatin-based chemotherapy.

Targeting Aurora kinase B attenuates chemoresistance in glioblastoma via a synergistic manner with temozolomide

BackgroundRecent studies have demonstrated that aberrant expression or activation of kinases results in oncogenesis of a wide range of cancers including GBM. Inhibition of kinases expression induces a reduction of therapy resistance. In this study, we investigate the underlying mechanism by which glioblastoma (GBM) cells acquire resistance to Temozolomide (TMZ) through Aurora kinase B (AURKB) thus to identify novel therapeutic targets and prognostic biomarkers for GBM. MethodsAURKB was identified as a key candidate kinase-encoding gene in chemoresistance regulation by using kinome-wide bioinformatic analysis. Afterwards, the potential biological functions of AURKB in oncogenesis and chemoresistance were investigated by lentivirus-dependent silencing of AURKB combined with qRT-PCR, western blot and in vivo intra-cranial xenograft mice models. Additionally, immunohistochemistry (IHC) assays were performed to explore the clinical significance of AURKB in glioma patients. Lastly, Chou-Talalay method was used to confirm the synergistic effect of TMZ combined with AURKB inhibitor. ResultsAURKB was among the most significantly up-regulated kinase-coding genes in TMZ resistant GBM cells according to database GSE68029, moreover, an increased expression of AURKB was closely associated with poor prognosis in glioma and GBM patients. AURKB knock-down resensitized U87 resistant cells to TMZ both in vitro and in vivo. Additionally, the combination of TMZ and Hesperadin, a specific AURKB inhibitor, significantly suppressed the proliferation of TMZ resistant GBM cells thus dramatically prolonged the survival of xenograft mice viaa synergistic effect with TMZ. ConclusionElevated AURKB expression was strongly correlated to TMZ resistant acquisition and poor prognosis, furthermore, targeting AURKB would be a potential therapeutic target for GBM patients.