Expression Of Aurora Research Articles

Analysis of checkpoint effect with fork head associated-and ring finger fusion enhanced green fluorescent protein on nasopharyngeal carcinoma 5–8F cells

As an oncogene related to mitosis cycle, checkpoint with fork head associated-(FHA) and ring finger (CHFR) participates in cell cycle and nasopharyngeal carcinoma (NPC). Enhanced Green fluorescent protein (EGFP) is a new type of fluorescent probe. In this study, the effect of CHFR fusion enhanced green fluorescent protein (EGFP) on nasopharyngeal carcinoma cells was analyzed. 5–8F human NPC cells were divided into control group, empty vector group (NC) and CHFR group (transfected with CHFR-pEGFP-N1-5–8F cell line). 12 BALB/c-nu mice were divided into control group, empty vector group and CHFR group. The following processes were assessed: cell proliferation, mitosis cycle, expression of CHFR, Aurora A, Cyclin-dependent kinase 2 (CDC2) and Cyclin B1, and tumor volume. Cell proliferation in the CHFR group was significantly lower at 24, 48 and 72 h. The NC and CHFR groups had increased cells in the G0/G1 phase and reduced cells in the S phase 24 h after subculture, without difference between the NC and CHFR groups. The CHFR group had decreased levels of Aurora A, CDC2 and CyclinB1, while tumor volume in 3 groups increased with increased time, and decreased at each time point for the CHFR group compared with other groups (p < 0.05). CHFR was highly expressed in the CHFR tumor group, which was significantly higher than other groups. The CHFR fusion EGFP protein can significantly inhibit Aurora A activity and expression of Aurora A, CDC2 and CyclinB1 by up-regulating the CHFR. The NPC cells were retained in the G0/G1 phase, blocking progression of cell mitosis, and further inhibiting cell proliferation while reducing tumor volume, and inhibiting the tumorigenic ability of NPC cells.

Effects of Aurora kinase A on mouse decidualization via Stat3-plk1-cdk1 pathway

BackgroundDecidualization is essential to the successful pregnancy in mice. The molecular mechanisms and effects of Aurora kinase A (Aurora A) remain poorly understood during pregnancy. This study is the first to investigate the expression and role of Aurora A during mouse decidualization.MethodsQuantitative real time polymerase chain reaction, western blotting and in situ hybridization were used to determine the expression of Aurora A in mouse uteri. Aurora A activity was inhibited by Aurora A inhibitor to explore the role of Aurora A on decidualization via regulating the Aurora A/Stat3/Plk1/Cdk1 signaling pathway.ResultsAurora A was strongly expressed at implantation sites compared with inter-implantation sites. Furthermore, Aurora A was also significantly increased in oil-induced deciduoma compared with control. Both Aurora A mRNA and protein were significantly increased under in vitro decidualization. Under in vitro decidualization, Prl8a2, a marker of mouse decidualization, was significantly decreased by TC-S 7010, an Aurora A inhibitor. Additionally, Prl8a2 was reduced by Stat3 inhibitor, Plk1 inhibitor and Cdk1 inhibitor, respectively. Moreover, the protein levels of p-Stat3, p-Plk1 and p-Cdk1 were suppressed by TC-S 7010. The protein levels of p-Stat3, p-Plk1 and p-Cdk1 were also suppressed by S3I-201, a Stat3 inhibitor). SBE 13 HCl (Plk1 inhibitor) could reduce the protein levels of p-Plk1 and p-Cdk1. Collectively, Aurora A could regulate Stat3/Plk1/Cdk1 signaling pathway.ConclusionOur study shows that Aurora A is expressed in decidual cells and should be important for mouse decidualization. Aurora A/Stat3/Plk1/Cdk1 signaling pathway may be involved in mouse decidualization.

USP48 Governs Cell Cycle Progression by Regulating the Protein Level of Aurora B

Deubiquitinating enzymes play key roles in the precise modulation of Aurora B—an essential cell cycle regulator. The expression of Aurora B increases before the onset of mitosis and decreases during mitotic exit; an imbalance in these levels has a severe impact on the fate of the cell cycle. Dysregulation of Aurora B can lead to aberrant chromosomal segregation and accumulation of errors during mitosis, eventually resulting in cytokinesis failure. Thus, it is essential to identify the precise regulatory mechanisms that modulate Aurora B levels during the cell division cycle. Using a deubiquitinase knockout strategy, we identified USP48 as an important candidate that can regulate Aurora B protein levels during the normal cell cycle. Here, we report that USP48 interacts with and stabilizes the Aurora B protein. Furthermore, we showed that the deubiquitinating activity of USP48 helps to maintain the steady-state levels of Aurora B protein by regulating its half-life. Finally, USP48 knockout resulted in delayed progression of cell cycle due to accumulation of mitotic defects and ultimately cytokinesis failure, suggesting the role of USP48 in cell cycle regulation.

Abstract PS6-52: Identification of Aurora kinase A as a biomarker for prognosis in obesity patients with early breast cancer

Abstract Background: Obesity is associated both with a higher risk of developing breast cancer, particularly in postmenopausal women, and with worse disease outcome for women of all ages. The molecular mechanisms that link obesity-breast cancer are complex and unclear. We hypothesized that overexpression of Aurora A was associated with poor survival in obesity breast cancer and related axis mechanism were involved.Methods: Fifty hundred and eighteen primary breast cancer specimens were collected from First Affiliated Hospital of China Medical University between January 2011 and November 2016. Our independent variable was BMI at baseline, categorized as overweight (BMI ≥ 25 kg/m2, as Obesity cohort), and normal (18.5 ≤ BMI < 25 kg/m2, as Non-obesity cohort). The Immunohistochemical (IHC) staining was performed with Aurora A, Survivin, MMP11, Cyclin B1 and Cathepsin L. Kaplan-Meier curve was used to analyze overall survival in our cohorts and TCGA-BRCA data (GSE3494). Log-rank test was used to calculate P value. PPI network analysis and MCODE model was used to analysis Aurora- altered signal pathway from GSE78958.Results: We validated Aurora A over expression using an independent cohort with a total of 517 breast carcinoma tissues (319 Non-Obesity patients and 198 Obesity Patients). The expression level of Aurora A-positive was significant higher in obesity breast carcinoma compared with non-obesity cancer carcinoma (χ2=9.79, P=0.002). In the immunohistochemistry assay, the results confirmed that the expression level of Aurora A-positive was significantly associated with hormone receptor status (68.4% vs 77.9%, P=0.015) and HER2 status (28.7% vs 17.9%, P=0.003). Aurora A-positive tumors had larger tumor size, though not statistically significant (78.1% vs. 71.1%, P=0.070). High Aurora A expression was remarkably and significantly associated with OS (8-year OS ratio: 69.5% vs 81.1%, OR=1.76, 95% CI:1.03~3.02, P=0.041) in Obesity Cohort. Interesting, higher expression of Aurora A was not associated with a shorter overall survival time among the Non-obesity breast cancer (8-year OS ratio:81.4% vs 85.8%, OR=1.40, 95% CI:0.79~2.45, P=0.229). As for RFS, the expression levels of Aurora A expression genes have no significance with RFS statistically in Non-Obesity patients. The in Aurora A low expression group was in high Aurora A expression in Non-Obesity Cohort ( 5-year RFS ratio:82.2% vs 83.2%, OR=1.29, 95% CI: 0.77~2.16, P=0.307). While 5-year RFS ratio in high Aurora A expression group of Aurora A were 71.3% was a little shorter than the 5-year RFS ratio in low Aurora A expression group (OR=1.58, 95% CI:0.96~2.57, P=0.072). Aurora A and Lymph node metastases were significantly poor prognostic factors for OS, and borderline significance was noted for high BMI. Kaplan-Meier survival analysis from TCGA database confirmed that the high Aurora A expression group had worse prognosis (HR=1.47, 95%CI:1.14-1.90, P=0.003). The KEGG pathway enrichment results were consistent with GO biological process term analysis, in which CCNB1 was enriched for upregulated Aurora A. In IHC correlation analyasis, Aurora A level on tumor cytoplasm had broad connections with Cyclin B1 (correlation coefficient = 0.227, P=0.001).Conclusions: Our finding demonstrate here for the first time that high expression of Aurora A was notably correlated with early recurrence and poor overall survival in obesity patients with early breast cancer. The Aurora A-Cyclin B1 axis could be a potential promising therapeutic target for cancer intervention and therapy. Keywords: Early breast cancer, obesity, Aurora A, Overall survival, Cyclin B1 Citation Format: Junnnan Xu, Tao Sun. Identification of Aurora kinase A as a biomarker for prognosis in obesity patients with early breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-52.

Agrin Yes-associated Protein Promotes the Proliferation of Epicardial Cells.

Embryonic epicardial cells make an important contribution to cardiac development. However, their proliferation mechanism is still unclear. Epicardial cells from E12.5 fetal hearts were used in our study. Agrin was used to treat these cells. The expression of Aurora B, Ki67, and pH3 was measured by quantitative reverse transcription-polymerase chain reaction and immunofluorescence. The proportion of cells in G1/S/G2 phase was determined by flow cytometry. The results showed that agrin significantly increased the expression of ki67, pH3, and Aurora B in epicardial cells. Flow cytometry results showed that agrin significantly increased the proportion of epicardial cells in S phase. However, blocking yes-associated protein significantly downregulated the levels of ki67, pH3, and Aurora B and the proportion of epicardial cells in S phase. Thus, our results suggest that agrin may promote the proliferation of epicardial cells by regulating the yes-associated protein activity. This may be useful in exploring heart development mechanisms and preventing congenital heart disease.

The Evaluation of Effect of Aurora Kinase Inhibitor CCT137690 in Melanoma and Melanoma Cancer Stem Cell.

Dysregulation of the cell cycle is one of the main causes of melanomagenesis. Genomewide studies showed that the expression of Aurora -A and -B significantly has been upregulated in melanoma. However, there is no FDA approved drug targeting aurora kinases in the treatment of melanoma. In addition, the development of resistance to chemotherapeutic agents in the treatment of melanoma and, as a result, the relapse due to heterogeneous cell groups in patients is a second phenomenon that causes treatment failure. Therefore, there is an urgent need for therapeutic alternatives targeting both melanoma and Melanoma Cancer Stem Cells (MCSCs) in treatments. At this stage, cell cycle regulators become promising targets. In this study, we aimed to identify the effects of Aurora kinase inhibitor CCT137690 on the cytotoxicity, apoptosis, cell cycle, migration, and colony formation and expression changes of genes related to proliferation, cell death and cell cycle in melanoma and melanoma cancer stem cell. In addition, we investigated the apoptotic and cytostatic effects of CCT137690 in normal fibroblast cells. We evaluated the cytotoxic effect of CCT137690 in MCSCs, NM2C5 referring as melanoma model cells and WI-38 cells by using the WST-1 test. The effect of CCT137690 on apoptosis was detected via Annexin V and JC-1 method; on cell cycle progression by cell cycle test; on gene expression by using RT-PCR, on migration activity by wound healing assay and clonal growth by clonogenic assay in NM2C5 cells and MCSCs. The effects of CCT137690 in WI-38, referring as healthy fibroblast cell, were assessed through Annexin V and cell cycle method. CCT137690 was determined to have a cytotoxic and apoptotic effect in MCSCs and melanoma. It caused polyploidy and cell cycle arrest at the G2/M phase in MCSCs and melanoma cells. The significant decrease in the expression of MMP2, MMP7, MMP10, CCNB1, IRAK1, PLK2 genes, and the increase in the expression of PTEN, CASP7, p53 genes were detected. Aurora kinases inhibitor CCT137690 displays promising anticancer activity in melanoma and especially melanoma cancer stem cells. The effect of CCT137690 on melanoma and MCSC may provide a new approach to treatment protocols.

The Aurora B specificity switch is required to protect from non-disjunction at the metaphase/anaphase transition

The Aurora B abscission checkpoint delays cytokinesis until resolution of DNA trapped in the cleavage furrow. This process involves PKCε phosphorylation of Aurora B S227. Assessing if this PKCε-Aurora B module provides a more widely exploited genome-protective control for the cell cycle, we show Aurora B phosphorylation at S227 by PKCε also occurs during mitosis. Expression of Aurora B S227A phenocopies inhibition of PKCε in by-passing the delay and resolution at anaphase entry that is associated with non-disjunction and catenation of sister chromatids. Implementation of this anaphase delay is reflected in PKCε activation following cell cycle dependent cleavage by caspase 7; knock-down of caspase 7 phenocopies PKCε loss, in a manner rescued by ectopically expressing/generating a free PKCε catalytic domain. Molecular dynamics indicates that Aurora B S227 phosphorylation induces conformational changes and this manifests in a profound switch in specificity towards S29 TopoIIα phosphorylation, a response necessary for catenation resolution during mitosis.

Aurora B kinase as a novel molecular target for inhibition the growth of osteosarcoma.

Osteosarcoma is the primary human malignant tumor affecting bone. This cancer most frequently arises in children and adolescents, with a second peak in those over the age of 50. Currently, surgery followed by radiotherapy and chemotherapy are the main treatments, but long-term positive effects are very poor. Aurora B kinase is a serine/threonine kinase that is a key regulator of cell cycle and mitosis. Tissue array analysis revealed that Aurora B kinase is overexpressed in osteosarcoma compared with normal bone tissue. We developed a compound, HOI-07 (i.e., (E)-3-((E)-4-(benzo[d] [1,3]dioxol-5-yl)-2-oxobut-3-en-1-ylidene)indolin-2-one), as a specific Aurora B kinase inhibitor and examined its effectiveness against osteosarcoma cell growth in this study. This compound inhibited Aurora B kinase activity in osteosarcoma and induced apoptosis, caused G2-M phase arrest, and attenuated osteosarcoma anchorage-independent cell growth. Moreover, knocking down the expression of Aurora B effectively reduced the sensitivity of osteosarcoma to HOI-07. Results of a xenograft mouse study indicated that HOI-07 treatment effectively suppressed the growth of 143B and KHOS xenografts, without affecting the body weight of mice. The expression of phosphorylated histone H3 (Ser10) was reduced in mice treated with HOI-07. Overall, we identified HOI-07 as a specific Aurora B kinase inhibitor for osteosarcoma treatment and this compound warrants further investigation.

Aurora B Kinase as a Novel Molecular Approach for Osteosarcoma Therapy

Osteosarcoma is the primary human malignant tumor affecting bone. This cancer most frequently arises in children and adolescents, with a second peak in those over the age of 50. Currently, surgery followed by radiotherapy and chemotherapy are the main treatments, but long-term positive effects are very poor. Aurora B kinase is a serine/threonine kinase that is a key regulator of cell cycle and mitosis. Tissue array analysis revealed that Aurora B kinase is overexpressed in osteosarcoma compared with normal bone tissue. We developed a compound, HOI-07 [i.e., (E)-3-((E)-4-(benzo[d] [1,3]dioxol-5-yl)-2-oxobut-3- en-1-ylidene)indolin-2-one], as a specific Aurora B kinase inhibitor and examined its effectiveness against osteosarcoma cell growth in this study. This compound inhibited Aurora B kinase activity in osteosarcoma and induced apoptosis, caused G2-M phase arrest, and attenuated osteosarcoma anchorage-independent cell growth. Moreover, knocking down the expression of Aurora B effectively reduced the sensitivity of osteosarcoma to HOI-07. Results of a xenograft mouse study indicated that HOI-07 treatment effectively suppressed the growth of 143B and KHOS xenografts, without affecting the body weight of mice. The expression of phosphorylated histone H3 (Ser10) was reduced in mice treated with HOI-07. Overall, we identified HOI-07 as a specific Aurora B kinase inhibitor for osteosarcoma treatment and this compound warrants further investigation. Funding Statement: This work was funded by The Hormel Foundation and National Institutes of Health grants CA166011, CA187027, and CA196639 and a Joint Funds of the National Natural Science Foundation of China (Grant No. 162300410337) Declaration of Interests: The authors declare none. Ethics Approval Statement: Mice were maintained under “specific pathogen-free” conditions based on the guidelines approved by the University of Minnesota Institutional Animal Care and Use Committee. PDX animal studies were preformed following guidelines approved by the Zhengzhou University Institutional Animal Care and Use Committee (Zhengzhou, Henan, China).

Abstract 1217: Blockade of Aurora kinase A synergizes with platinum and radiation in non-small cell lung cancer cells

Abstract Background: Most patients with advanced lung cancer will receive platinum-based therapy during their treatment course despite limited clinical benefits. Thus, strategies to improve platinum-based therapy continue to be needed. Through a functional genetic screen, we have identified Aurora kinase A as a potentially actionable candidate that can modulate the activity of platinum compounds. Aurora A is a serine/threonine kinase and a key regulator of the mitotic process. Through its mitotic and non-mitotic roles, the aberrant activation of Aurora A can lead to oncogenic transformation and has emerged as a promising therapeutic target in cancer. METHODS: High-throughput RNAi screen was used to identify potential candidates for cisplatin resistance. Cell proliferation/viability was determined by MTS assays and colony formation assays. Immunohistochemistry was performed to determine the overexpression of Aurora A in specimens from lung cancer patients. Western blot was used to explore the cell signaling mechanisms in cisplatin, radiation, and/or MLN8237 (alisertib) treated NSCLC cell lines. β-Galactosidase staining was performed to determine the senescence following cisplatin and/or MLN8237 treatment in NSCLC cell lines. RESULTS: Aurora Kinase A is widely expressed in lung cancer specimens. The expression of Aurora A is upregulated following treatment with Cisplatin in NSCLC cells, such as PC9, A549, H1703, and H460. Inhibition of Aurora A activity with either siRNA-mediated knockdown or pharmacological blockade (MLN8237) significantly improved sensitivities to cisplatin and ionizing radiation, both of which cause DNA damage and cell death. On the other hand, inhibition of Aurora A activity by itself was associated with reduced cell proliferation and survival of NSCLC cell lines. Moreover, co-administration with Cisplatin and AURKA siRNA resulted in sustained DNA double strand breaks and more pronounced apoptosis. The combination of AURKA inhibitor (MLN8237) with Cisplatin similarly led to enhanced DNA damage. Similar effects were observed with radiation concomitant with inhibition of Aurora A. Furthermore, MLN8237 induced marked apoptosis in the p53 mutant cell line, PC9, whereas more senescence was noted in p53 wild type A549 cells. CONCLUSIONS: Our study indicates a significant role for Aurora Kinase A as a common modulator of p53-dependent resistance in the context of DNA-damaging platinum and radiation therapy. Aurora A inhibition can potentially improve the efficacy of these common treatment modalities in lung cancer management. Citation Format: Huijie Liu, Dongwei Zhang, Alain Borczuk, Vincent Chau, Roman Perez-Soler, Balazs Halmos, Haiying Cheng. Blockade of Aurora kinase A synergizes with platinum and radiation in non-small cell lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1217. doi:10.1158/1538-7445.AM2017-1217

Characterization of Aurora A and Its Impact on the Effect of Cisplatin-Based Chemotherapy in Patients with Non–Small Cell Lung Cancer

BACKGROUND AND OBJECTIVE: Aurora A, as a member of serine/threonine kinase family and a common characteristic of epithelial cancers, plays a critical role in cell mitosis. However, the clinical significance of Aurora A in non–small cell lung cancer (NSCLC) remains undetermined. METHODS: The expression of Aurora A in NSCLC and paired normal adjacent lung tissues was determined by immunohistochemistry, Western blot, and reverse transcriptase polymerase chain reaction. Receiver operating characteristic (ROC) curve analysis was employed to determine a cutoff score for Aurora A expression in a training set (n=135). For validation, the ROC-derived cutoff score was subjected to analysis of the association of Aurora A expression with patient outcome and clinicopathological characteristics in a testing set (n=128) and overall patients (n=263). The correlation of Aurora A with cisplatin resistance and epithelial-mesenchymal transition (EMT) was examined in vitro in NSCLC cells by overexpression or knockdown of Aurora A. RESULTS: Aurora A expression was significantly upregulated in tumor tissues compared with paired normal tissues (P<.01). The expression of Aurora A was closely associated with clinical stage, lymph node metastasis, and recurrence and was an independent prognostic parameter in multivariate analysis. High level of Aurora A expression predicted poorer overall survival and disease-free survival in NSCLC patients treated with cisplatin-based adjuvant chemotherapy. In vitro data showed that overexpression or knockdown of Aurora A resulted in increased or decreased cellular resistance to cisplatin. Furthermore, inhibition of Aurora A reversed the EMT process. CONCLUSIONS: Aurora A was identified as an inferior prognostic and cisplatin-resistant biomarker in NSCLC patients, which provided potential evidences for therapeutic target and reversing drug resistance.

Abstract 1892: Investigating the role of Aurora Kinase A as a positive regulator of MAPK signaling

Abstract Aurora Kinase A (Aurora A), a protein canonically known to facilitate mitosis, has emerged as a promising drug target for cancer therapy. Aurora A is amplified in several cancer types, including glioblastoma, breast, and ovarian cancer, and increased expression is correlated to a worse prognosis for patients. In spite of these observations, the impact of increased Aurora A expression on cell signaling and cancer development remains unclear. Aurora A is also mis-localized to the cytoplasm in cancer and engages in oncogenic functions mediated through protein-protein interactions (PPIs). Thus, we hypothesized that through novel PPIs, Aurora A may be promoting oncogenic signaling and cancer cell growth. The acquired ability of cancer cells to sustain proliferative signaling is a cancer hallmark. One critical pathway through which mutations drive the development of several cancer types is the Ras-Raf-MEK-ERK signaling cascade, which is also known as the mitogen-associated protein kinase (Ras-MAPK) pathway. When we co-expressed Aurora A and H-Ras in both HEK-293T cells and the glioblastoma cancer cell line, 8-MG-BA, ERK phosphorylation increased compared to expression of Aurora A or H-Ras alone. However, pharmacological inhibition of Raf-1 and MEK was able to block the increase in ERK phosphorylation by Aurora A and H-Ras co-expression. In addition, Aurora A was not able to promote ERK phosphorylation when co-expressed with dominant negative H-Ras (S17N mutant). Together, these findings demonstrate that Aurora A requires the MAPK signaling cascade to potentiate ERK activation. Interestingly, we discovered that this effect correlates to a novel interaction between Aurora A and H-Ras. The Aurora A/H-Ras interaction was confirmed using the lysate-based assay, Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET), the affinity-based assay, GST-pull down, and in live cells using the Venus Protein-fragment Complementation Assay (PCA). Through deletion analysis, the binding domains critical to mediate the interaction of Aurora A and H-Ras were characterized. We also determined that H-Ras is not an enzymatic substrate for Aurora A using an in vitro kinase assay and found that cells treated with an Aurora A kinase inhibitor are able to maintain the Aurora A/H-Ras the interaction, suggesting that the Aurora A/H-Ras interaction is kinase-independent. In conclusion, our studies reveal a role for Aurora A as a positive regulator of Ras-MAPK proliferative signaling. As Aurora A gene expression is downstream of the Ras-MAPK signaling pathway, our data also provides a mechanism by which Aurora A forms a positive feedback loop, linking Aurora A to sustained proliferative signaling in cancer cells. Finally, the kinase-independence of the Aurora A/H-Ras interaction underscores the consideration that Aurora A kinase inhibitors currently in clinical development may not be sufficient to block all oncogenic functions of Aurora A. Citation Format: MaKendra Umstead, Jinglin Xiong, Zenggang Li, Andrei Ivanov, Yuhong Du, Haian Fu. Investigating the role of Aurora Kinase A as a positive regulator of MAPK signaling. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1892.

Downregulation of the PHLDA1 gene in IMR-32 neuroblastoma cells increases levels of AuroraA, TRKB and affects proteins involved in apoptosis and autophagy pathways.

We have recently shown that mRNA and protein of PHLDA1 (pleckstrin-homology-like domain familyA, member 1) were by far the most upregulated molecules upon treatment of IMR-32 cells with the anti-GD2 ganglioside monoclonal antibody 14G2a. Hence, we decided to study functions of PHLDA1 using human neuroblastoma IMR-32 cells as a model. Here, we show that constitutive expression of mRNA and protein of the PHLDA1 gene in IMR-32 cells was inversely correlated with transcript of the AURKA gene and AuroraA oncoprotein. Next, we silenced PHLDA1 expression in IMR-32 cells using an shRNA interference method. We report that IMR-32 cells with stable downregulation of PHLDA1 showed enhanced cellular ATP levels and an increase in mitochondrial membrane potential, as compared to control and non-transduced cells. We demonstrated that downregulation of PHLDA1 leads to a significant increase in expression of AuroraA and TRKB that are markers of poor prognosis in neuroblastoma. Also, we measured an increase in AuroraA and Akt kinases phosphorylation in the cells. Most importantly, PHLDA1-silenced cells were less susceptible to apoptosis than control cells, as shown by the lower expression of cleaved caspase-3 and PARP as well as a decreased activity of caspase-3 and -7. Our study negatively correlates expression of PHLDA1 and AuroraA in IMR-32 cells and sheds new light on functions of PHLDA1 in the neuroblastoma tumor cells, suggesting its role as a pro-apoptotic protein. Additionally, our results show possible links of the protein to regulation of features of mitochondria and formation of autophagosomes.

San Huang Decoction downregulates Aurora kinase A to inhibit breast cancer cell growth and enhance chemosenstivity to anti-tumor drugs

Our study aimed to explore whether San Huang Decoction (SHD) inhibited the development of breast cancer by regulating Aurora A. Human breast cancer cell lines MCF-7 and MDA-MB-231 were cultured and SHD extract was prepared. Cell growth assay and apoptosis analysis were respectively performed to detect the effects of SHD on breast cancer cells. In addition, the effects of SHD on the expression of Aurora A and p53 were determined by RT-PCR and western blot. Besides, we used Aurora A siRNA to knock down Aurora A. We then co-administrated SHD and tamoxifen or epirubicin to detect the effect of SHD on chemosensitivity to tamoxifen or epirubicin. SHD treatment significantly inhibited cell growth in a dose-dependent manner. Moreover, SHD treatment resulted in a marked decrease in Aurora A expression and obvious increase in p53 expression. In addition, knockdown of Aurora A induced cell growth inhibition, which was similar to the effect of SHD treatment. Besides, SHD exerted an additive effect on cell growth inhibition and apoptosis induction when breast cancer cells were co-administration of SHD with tamoxifen or epirubicin. Our study indicates that SHD treatment may inhibit cell growth and enhance chemosenstivity to other anti-tumor drugs in breast cancer via down-regulation of Aurora A.

Activation of Aurora A kinase through the FGF1/FGFR signaling axis sustains the stem cell characteristics of glioblastoma cells

Fibroblast growth factor 1 (FGF1) binds and activates FGF receptors, thereby regulating cell proliferation and neurogenesis. Human FGF1 gene 1B promoter (−540 to +31)-driven SV40 T antigen has been shown to result in tumorigenesis in the brains of transgenic mice. FGF1B promoter (−540 to +31)-driven green fluorescent protein (F1BGFP) has also been used in isolating neural stem cells (NSCs) with self-renewal and multipotency from developing and adult mouse brains. In this study, we provide six lines of evidence to demonstrate that FGF1/FGFR signaling is implicated in the expression of Aurora A (AurA) and the activation of its kinase domain (Thr288 phosphorylation) in the maintenance of glioblastoma (GBM) cells and NSCs. First, treatment of FGF1 increases AurA expression in human GBM cell lines. Second, using fluorescence-activated cell sorting, we observed that F1BGFP reporter facilitates the isolation of F1BGFP(+) GBM cells with higher expression levels of FGFR and AurA. Third, both FGFR inhibitor (SU5402) and AurA inhibitor (VX680) could down-regulate F1BGFP-dependent AurA activity. Fourth, inhibition of AurA activity by two different AurA inhibitors (VX680 and valproic acid) not only reduced neurosphere formation but also induced neuronal differentiation of F1BGFP(+) GBM cells. Fifth, flow cytometric analyses demonstrated that F1BGFP(+) GBM cells possessed different NSC cell surface markers. Finally, inhibition of AurA by VX680 reduced the neurosphere formation of different types of NSCs. Our results show that activation of AurA kinase through FGF1/FGFR signaling axis sustains the stem cell characteristics of GBM cells. ImplicationsThis study identified a novel mechanism for the malignancy of GBM, which could be a potential therapeutic target for GBM.

Head-to-head comparison of the impact of Aurora A, Aurora B, Repp86, CDK1, CDK2 and Ki67 expression in two of the most relevant gynaecological tumor entities.

The dysregulation of cell cycle kinases plays a crucial role in carcinogenesis and the expression of various kinases has been attributed to aggressive tumor growth and an unfavourable prognosis in oncological patients. We, therefore, aimed to evaluate the expression of Ki67 among five additional cell cycle kinases in a collective of mammary and ovarian tumor specimens and to find a correlation with clinicopathological parameters. 76 mammary and 93 ovarian benign and malignant tumor samples were immunohistochemically stained and evaluated for the expression of Aurora A and B, Repp86, CDK1 and 2 (only breast specimens) and Ki67. The expression patterns of these cell cycle kinases were matched with retrospectively collected clinicopathological parameters. All examined cell cycle kinases accurately discriminated benign from malignant breast and ovarian tissues. In breast cancer, Aurora A and B-, Repp86-, CDK2- and Ki67-expression was inversely associated with ER expression. No correlation with the HER2-status was found in our collective. Importantly, we found a significant correlation between the expression of Aurora A and CDK1 and axillary lymph node metastasis in breast cancer. Furthermore, a shortened disease free survival (DFS) upon expression of Aurora B and CDK2 was shown in breast cancer patients. None of the cell cycle kinases was associated with predictive or prognostic factors in epithelial ovarian cancer. The prognostic value of the expression of Ki67 is overtrumped by alternative cell cycle kinases when it comes to prediction of axillary tumor spread and a shortened DFS, which might allow a further risk stratification in breast cancer patients.

Prognostic value of combined expression of Aurora A, p53 and p21 WAF1 in patients after curative resection of non-small cell lung cancer

The aim of this study was to investigate the prognostic value of combined expression of Aurora A, Ki-67, p53 and p21 WAF1 in patients after curative resection of non-small cell lung cancer (NSCLC). Expressions of Aurora A, Ki-67, p53 and p21 WAF1 in 58 tumor samples from resected primary NSCLCs were detected by immunohistochemistry. The correlation of proteins, survival and clinicopathological characteristics was analyzed. The positive rates of Aurora A, Ki-67, p53 and p21 WAF1 expression were 89.7% (52/58), 53.4% (31/58), 46.6% (27/58) and 34.5% (20/58), respectively. Aurora A expression was positively correlated with nodal metastasis (69.2% vs. 37.8%, P = 0.045). The univariable analysis showed that the overall survival (OS) was 75.0%in patients with low Aurora A expression and 46.0% in patients with high Aurora A expression (P = 0.039). The 3-year survival rate was 40.0% in patients with positive expression of Aurora A and p53, 65.0% in the patients with positive expression of Aurora A or p53, and 82.1% in the patients with negative expression of Aurora A and p53 (P = 0.039). The Cox regression model showed that combined expression of Aurora and p53 is an independent factor affecting the prognosis of NSCLC patients (P = 0.015). Our findings suggest that the positive expression of Aurora A, Ki-67 and p53 proteins is an unfavorable factor affecting the prognosis for NSCLC patients, and the overexpression of Aurora A is an independent unfavorable factor association with shorter OS in NSCLC patients. Detection of positive Aurora A and p53 expression may be a useful predictive prognostic indicator for NSCLC patients.

Aurora B expression and histone variant H1.4S27 phosphorylation are no longer coordinated during metaphase in aneuploid colorectal carcinomas.

Experimental model systems identified phosphorylation of linker histone variant H1.4 at Ser 27 (H1.4S27p) as a novel mitotic mark set by Aurora B kinase. Here, we examined expression of Aurora B and H1.4S27p in colorectal carcinoma (CRC) cell lines (HCT116, DLD1, Caco-2, HT29) and tissue specimens (n = 36), in relation to microsatellite instability (MSI) status and ploidy. In vitro, Aurora B (pro-/meta-/anaphase) and H1.4S27p (pro-/metaphase) were localized in mitotic figures. The proportion of labeled mitoses was significantly different between cell lines for Aurora B (p = 0.019) but not for H1.4S27p (p = 0.879). For Aurora B, these differences were not associated with an altered Aurora B gene copy number (FISH) or messenger RNA (mRNA) expression level (qRT-PCR). Moreover, Aurora B expression and H1.4S27 phosphorylation were no longer coordinated during metaphase in aneuploid HT29 cells (p = 0.039). In CRCs, immunoreactivity for Aurora B or H1.4S27p did not correlate with T- or N-stage, grade, or MSI status. However, metaphase labeling of H1.4S27p was significantly higher in diploid than in aneuploid CRCs (p = 0.011). Aurora B was significantly correlated with H1.4S27p-positive metaphases in MSI (p = 0.010) or diploid (p = 0.003) CRCs. Finally, combined classification of MSI status and ploidy revealed a significant positive correlation of Aurora B with H1.4S27p in metaphases of diploid/MSI (p = 0.010) and diploid/microsatellite-stable (MSS; p = 0.031) but not of aneuploid/MSS (p = 0.458) CRCs. The present study underlines the functional link of Aurora B expression and H1.4S27p during specific phases of mitosis in diploid and/or MSI-positive CRCs in vitro and in situ. Importantly, the study shows that the coordination between Aurora B expression and phosphorylation of H1.4 at Ser 27 is lost in cycling aneuploid CRC cells.

A Phase I Trial of Alisertib Plus Romidepsin for Relapsed/Refractory Aggressive B- and T-Cell Lymphomas

A Phase I Trial of Alisertib Plus Romidepsin for Relapsed/Refractory Aggressive B- and T-Cell Lymphomas

Regulation of the subcellular shuttling of Sgo1 between centromeres and chromosome arms by Aurora B-mediated phosphorylation

A minor fraction of cohesin complexes at chromosome arms is not removed by the prophase pathway, and maintained until metaphase and enriched at centromeres. Sgo1 localizes to chromosome arms from prophase to metaphase, and is indispensable for removing cohesin complexes from chromosome arms. However, it has not been established how the chromosome arm localization of Sgo1 leads to the establishment of cohesion on chromosomes. Here, we report that Aurora B kinase interacts with and phosphorylates Sgo1 in vitro and in vivo. Furthermore, the phosphorylation of Sgol by Aurora B kinase regulated the distribution of Sgo1 between centromeres and chromosome arms, and the expression of Aurora B kinase-dead mutants of Sgo1 caused mislocalization from centromeres to chromosome arms. These results suggest Aurora B kinase directly regulates the subcellular distribution of Sgo1 to facilitate the accurate separation of mitotic chromosomes