Increased AURKA promotes cell proliferation and predicts poor prognosis in bladder cancer.
ABSTRACT: BACKGROUND:Bladder cancer (BC) is the most common cancer of the urinary bladder and upper tract, in which the clinical management is limited. AURKA (aurora kinase A) has been identified as an oncogene in cancer development; however, its potential role and underlying mechanisms in the progression of BC remain unknown. RESULTS:In this study, we evaluated Aurora kinase A (AURKA) expression in patient samples by performing gene expression profiling, and found that AURKA expression levels were significantly higher in BC tissues than in normal tissues. Increased AURKA in BC was strongly associated with stage and grade. Moreover, BC patients with elevated AURKA achieved poor overall survival rates. The experiments in vitro comprehensively validated the critical role of AURKA in promoting BC cell proliferation using the methods of gene overexpression and gene silencing. Furthermore, we proved that AURKA inhibitor MLN8237 arrested BC cell growth and induced apoptosis. CONCLUSIONS:These findings implicate AURKA acting as an effective biomarker for BC detection and prognosis, as well as therapeutic target.
Project description:Abnormal expression or mutation of RNA splicing proteins are widely observed in human cancers. Here, we identified poly(U) binding splicing factor 60 (PUF60) as one of the most differentially expressed genes out of 97 RNA splicing proteins between normal and bladder cancer tissues by bioinformatics analysis of TCGA bladder cancer expression data. The expression of PUF60 was significantly higher in tumor tissues, while high PUF60 expression was associated with malignant phenotypes of bladder cancer and shorter survival time. Moreover, we identified aurora kinase A (AURKA) as a new downstream target of PUF60 in bladder cancer cells. PUF60 knockdown significantly inhibited cell viability and colony formation capacity in bladder cancer cells, whereas AURKA overexpression reversed this inhibition effect. Overexpression of PUF60 significantly promoted cell viability and colony formation in bladder cancer cells, while treatment with AURKA specific inhibitor reversed this promotive effect. Mechanistically, PUF60 specifically bound to the AURKA promoter, thereby activating its transcription and expression. Furthermore, we showed that there was a significant positive correlation between PUF60 and AURKA expression in bladder cancer tissues, and PUF60 and AURKA expression contributed to tumor progression and malignant phenotypes in the patients with bladder cancer. Collectively, these results indicate that the PUF60/AURKA axis plays a key role in regulating tumorigenesis and progression of bladder cancer, and may be a potential prognostic biomarker and therapeutic target for bladder cancer patients.
Project description:Gastric cancer, a highly invasive and aggressive malignancy, is the third leading cause of death from cancer worldwide. Genetic association studies have successfully revealed several important genes consistently associated with gastric cancer to date. However, these robust gastric cancer-associated genes do not fully elucidate the mechanisms underlying the development and progression of the disease. In the present study, we performed an alternative approach, a gene expression-based genome-wide association study (eGWAS) across 13 independent microarray experiments (including 251 gastric cancer cases and 428 controls), to identify top candidates (p<0.00001). Additionally, we conducted gene ontology analysis, pathway analysis and network analysis and identified aurora kinase A (AURKA) as our candidate. We observed that MLN8237, which is a specific inhibitor of AURKA, decreased the ?-catenin and the phosphorylation of Akt1 and GSK-3?, as well as blocked the Akt and Wnt signaling pathways. Furthermore, MLN8237 arrested the cells in the G2/M phase. The activity of Wnt and Akt signaling pathways affected the level of histone methylation significantly, and we supposed that MLN8237 affected the level of histone methylation through these two signaling pathways. Additionally, the treatment of MLN8237 influenced the level of H3K4 me1/2/3 and H3K27 me1/2/3. Chip data on cell lines suggested that MLN8237 increases the level of H3K27 me3 on the promoter of Twist and inhibits EMT (epithelial-mesenchymal transition). In summary, AURKA is a potential therapeutic target in gastric cancer and induces EMT through histone methylation.
Project description:Although second generation endocrine therapies have significantly improved survival, castration-resistant prostate cancer (CRPC) cells are eventually able to escape available hormonal treatments due to reactivation of androgen receptor (AR) signaling. Identification of novel, non-classical and druggable AR-target genes may provide new approaches to treat CRPC. Our previous analyses suggested that Aurora kinase A (AURKA) is regulated by androgens in prostate cancer cells that express high levels of AR. Here, we provide further evidence that AURKA is significantly overexpressed in AR-positive CRPC samples carrying amplification of AR gene and/or expressing AR in high levels. We also demonstrate androgen-induced AR binding in the intronic region of AURKA. The expression of AURKA is increased upon androgen stimulation in LNCaP-ARhi cells that express high levels of AR. The growth of the cells was also significantly inhibited by an AURKA specific inhibitor, alisertib (MLN8237). Together, these findings suggest that the expression of AURKA is regulated by androgen in prostate cancer cells that highly express AR, emphasizing its potential as a therapeutic target in patients with CRPC.
Project description:Aurora kinase A is a frequently amplified and overexpressed gene in upper gastrointestinal adenocarcinomas (UGCs). Using in vitro cell models of UGCs, we investigated whether AURKA can regulate Signal Transducer and Activator of Transcription 3 (STAT3). Our data indicate that overexpression of AURKA in FLO-1 and AGS cells increase STAT3 phosphorylation at the Tyr705 site, whereas AURKA genetic depletion by siRNA results in decreased phosphorylation levels of STAT3 in FLO-1 and MKN45 cells. Immunofluorescence analysis showed that AURKA overexpression enhanced STAT3 nuclear translocation while AURKA genetic knockdown reduced the nuclear translocation of STAT3 in AGS and FLO-1 cells, respectively. Using a luciferase reporter assay, we demonstrated that AURKA expression induces transcriptional activity of STAT3. Pharmacological inhibition of AURKA by MLN8237 reduced STAT3 phosphorylation along with down-regulation of STAT3 pro-survival targets, BCL2 and MCL1. Moreover, by using clonogenic cells survival assay, we showed that MLN8237 single dose treatment reduced the ability of FLO-1 and AGS cells to form colonies. Additional experiments utilizing cell models of overexpression and knockdown of AURKA indicated that STAT3 upstream non-receptor tyrosine kinase Janus kinase 2 (JAK2) is mediating the effect of AURKA on STAT3. The inhibition of JAK2 using JAK2-specific inhibitor AZD1480 or siRNA knockdown, in presence of AURKA overexpression, abrogated the AURKA-mediated STAT3 activation. These results confirm that the AURKA-JAK2 axis is the main mechanism by which AURKA regulates STAT3 activity. In conclusion, we report, for the first time, that AURKA promotes STAT3 activity through regulating the expression and phosphorylation levels of JAK2. This highlights the importance of targeting AURKA as a therapeutic approach to treat gastric and esophageal cancers.
Project description:Primary myelofibrosis (PMF) is characterized by bone marrow fibrosis, myeloproliferation, extramedullary hematopoiesis, splenomegaly and leukemic progression. Moreover, the bone marrow and spleens of individuals with PMF contain large numbers of atypical megakaryocytes that are postulated to contribute to fibrosis through the release of cytokines, including transforming growth factor (TGF)-?. Although the Janus kinase inhibitor ruxolitinib provides symptomatic relief, it does not reduce the mutant allele burden or substantially reverse fibrosis. Here we show through pharmacologic and genetic studies that aurora kinase A (AURKA) represents a new therapeutic target in PMF. Treatment with MLN8237, a selective AURKA inhibitor, promoted polyploidization and differentiation of megakaryocytes with PMF-associated mutations and had potent antifibrotic and antitumor activity in vivo in mouse models of PMF. Moreover, heterozygous deletion of Aurka was sufficient to ameliorate fibrosis and other PMF features in vivo. Our data suggest that megakaryocytes drive fibrosis in PMF and that targeting them with AURKA inhibitors has the potential to provide therapeutic benefit.
Project description:Despite more than 70,000 new cases of bladder cancer in the United States annually, patients with advanced disease have a poor prognosis due to limited treatment modalities. We evaluated Aurora kinase A, identified as an upregulated candidate molecule in bladder cancer, as a potential therapeutic target.Gene expression in human bladder cancer samples was evaluated using RNA microarray and quantitative reverse transcriptase PCR. Effects of the Aurora kinase A inhibitor MLN8237 (Millennium) on cell dynamics in malignant T24 and UM-UC-3 and papilloma-derived RT4 bladder cells were evaluated in vitro and in vivo in a mouse xenograft model.A set of 13 genes involved in the mitotic spindle checkpoint, including Aurora kinases A and B, were upregulated in human urothelial carcinoma compared with normal urothelium. The Aurora kinase A inhibitor MLN8237 induced cell-cycle arrest, aneuploidy, mitotic spindle failure, and apoptosis in the human bladder cancer cell lines T24 and UM-UC-3. MLN8237 also arrested tumor growth when administered orally over 4 weeks in a mouse bladder cancer xenograft model. Finally, in vitro sequential administration of MLN8237 with either paclitaxel or gemcitabine resulted in synergistic cytotoxic effects in T24 cells.Mitotic spindle checkpoint dysfunction is a common characteristic of human urothelial carcinoma and can be exploited with pharmacologic Aurora A inhibition. Given our demonstration of the ability of the Aurora A inhibitor MLN8237 to inhibit growth of bladder cancer in vitro and in vivo, we conclude that Aurora kinase inhibitors warrant further therapeutic investigation in bladder cancer.
Project description:MITF (microphthalmia-associated transcription factor) is a frequently amplified lineage-specific oncogene in human melanoma, whose role in intrinsic drug resistance has not been systematically investigated. Utilizing chemical inhibitors for major signaling pathways/cellular processes, we witness MITF as an elicitor of intrinsic drug resistance. To search kinase(s) targets able to bypass MITF-conferred drug resistance, we employed a multi-kinase inhibitor-directed chemical proteomics-based differential affinity screen in human melanocytes carrying ectopic MITF overexpression. A subsequent methodical interrogation informed mitotic Ser/Thr kinase Aurora Kinase A (AURKA) as a crucial regulator of melanoma cell proliferation and migration, independent of the underlying molecular alterations, including TP53 functional status and MITF levels. Crucially, assessing the efficacy of investigational AURKA inhibitor MLN8237, we pre-emptively witness the procurement of a molecular program consistent with acquired drug resistance. This involved induction of multiple MAPK (mitogen-activated protein kinase) signaling pathway components and their downstream proliferation effectors (Cyclin D1 and c-JUN) and apoptotic regulators (MITF and Bcl-2). A concomitant AURKA/BRAF and AURKA/MEK targeting overcame MAPK signaling activation-associated resistance signature in BRAF- and NRAS-mutated melanomas, respectively, and elicited heightened anti-proliferative activity and apoptotic cell death. These findings reveal a previously unreported MAPK signaling-mediated mechanism of immediate resistance to AURKA inhibitors. These findings could bear significant implications for the application and the success of anti-AURKA approaches that have already entered phase-II clinical trials for human melanoma.
Project description:Aurora kinase A (AURKA) belongs to the family of serine/threonine kinases, whose activation is necessary for cell division processes via regulation of mitosis. AURKA shows significantly higher expression in cancer tissues than in normal control tissues for multiple tumor types according to the TCGA database. Activation of AURKA has been demonstrated to play an important role in a wide range of cancers, and numerous AURKA substrates have been identified. AURKA-mediated phosphorylation can regulate the functions of AURKA substrates, some of which are mitosis regulators, tumor suppressors or oncogenes. In addition, enrichment of AURKA-interacting proteins with KEGG pathway and GO analysis have demonstrated that these proteins are involved in classic oncogenic pathways. All of this evidence favors the idea of AURKA as a target for cancer therapy, and some small molecules targeting AURKA have been discovered. These AURKA inhibitors (AKIs) have been tested in preclinical studies, and some of them have been subjected to clinical trials as monotherapies or in combination with classic chemotherapy or other targeted therapies.
Project description:PURPOSE: Despite over 70,000 new cases of bladder cancer in the United States annually, patients with advanced disease have a poor prognosis due to limited treatment modalities. We evaluate the role of Aurora A, identified as an upregulated candidate molecule in bladder cancer, in regulating bladder tumor growth. EXPERIMENTAL DESIGN: Gene expression in human bladder cancer samples was evaluated using RNA microarray and reverse-transcriptase PCR. The specific Aurora kinase A inhibitor MLN8237 (Millennium) was used to determine effects on bladder cancer cell growth using in vitro and in vivo models using malignant T24 and UM-UC-3 and papilloma-derived RT4 bladder cells. RESULTS: Urothelial carcinoma upregulates a set of 13 mitotic spindle associated transcripts, as compared to normal urothelium, including MAD2L1 (7.6-fold), BUB1B (8.8-fold), Aurora kinases A (5.6-fold) and Aurora kinase B (6.2-fold). Application of MLN8237 (10nM-1µM) to the human bladder tumor cell lines T24 and UM-UC-3 induced dose-dependent G2 cell cycle arrest, aneuploidy, mitotic spindle abnormalities, and apoptosis. MLN8237 arrested tumor growth when administered orally over 4 weeks in a mouse bladder cancer xenograft model (p<0.05). Finally, in vitro combination of MLN8237 with either paclitaxel or gemcitabine produced schedule-dependent synergistic antiproliferative effects in T24 cells when administered sequentially. CONCLUSIONS: Mitotic spindle checkpoint dysfunction is a common characteristic of human urothelial carcinoma, and can be exploited with pharmacologic Aurora A inhibition. Future studies that explore the mechanisms of spindle checkpoint failure in bladder cancer and evaluate the therapeutic role of Aurora kinases for bladder cancer patients would be of value. Tissue samples with urothelial cell carcinoma from bladder as well as normal references were collected and the gene expression profiles were compared. No technical replicates.
Project description:Lung cancer is the most deadly malignancy in the last decade, accounting for about 1.6 million deaths every year globally. Tanshinone is the constituent of Salvia miltiorrhiza; it has been found that they influence tumorigenesis. However, the role of tanshinones on lung cancer is still not clear. Let-7a-5p, a short non-coding RNA, is regarded as a suppressor gene in tumorigenesis. Herein, we verified that let-7a-5p is significantly downregulated in non-small-cell lung cancer (NSCLC) tissues and cell lines. Tanshinone suppressed the expression of aurora kinase A (AURKA), inhibited cell proliferation, and arrested cell cycle progression. Our results showed that tanshinones suppressed NSCLC by upregulating the expressions of let-7a-5p via directly targeting AURKA. Besides, the data reveal that the knockdown of AURKA can also inhibit cell proliferation, arrest cell cycle, and promote cell apoptosis. Furthermore, this study demonstrates that AURKA was negatively correlated with let-7a-5p in NSCLC patient tissues. Taken together, our findings suggest that tanshinone inhibits NSCLC by downregulating AURKA through let-7a-5p. Tanshinones and let-7a-5p have the potential to be candidates for drug development of NSCLC. In conclusion, this study revealed that tanshinones with miRNA linking lead to partial mechanism in NSCLC.