Aurora Kinase A expression is associated with lung cancer histological-subtypes and with tumor de-differentiation

A comprehensive review on role of Aurora kinase inhibitors (AKIs) in cancer therapeutics

Aurora kinases (AURKs) are a family of serine /threonine protein kinases that have a crucial role in cell cycle process mainly in the event of chromosomal segregation, centrosome maturation and cytokinesis. The family consists of three members including Aurora kinase A (AURK-A), Aurora kinase B (AURK-B) and Aurora kinase C (AURK-C). All AURKs contain a conserved kinase domain for their activity but differ in their cellular localization and functions. AURK-A and AURK-B are expressed mainly in somatic cells while the expression of AURK-C is limited to germ cells. AURK-A promotes G2 to M transition of cell cycle by controlling centrosome maturation and mitotic spindle assembly. AURK-B and AURK-C form the chromosome passenger complex (CPC) that ensures proper chromosomal alignments and segregation. Aberrant expression of AURK-A and AURK-B has been detected in several solid tumours and malignancies. Hence, they have become an attractive therapeutic target against cancer. The first part of this review focuses on AURKs structure, functions, subcellular localization, and their role in tumorigenesis. The review also highlights the functional and clinical impact of selective as well as pan kinase inhibitors. Currently, >60 compounds that target AURKs are in preclinical and clinical studies. The drawbacks of existing inhibitors like selectivity, drug resistance and toxicity have also been addressed. Since, majority of inhibitors are Aurora kinase inhibitor (AKI) type-1 that bind to the active (DFGin and Cin) conformation of the kinase, this information may be utilized to design highly selective kinase inhibitors that can be combined with other therapeutic agents for better clinical outcomes.

Identification of tumor-suppressor genes in lung squamous cell carcinoma through integrated bioinformatics analyses

Lung cancer is a prevalent malignancy, and fatalities of the disease exceed 400,000 cases worldwide. Lung squamous cell carcinoma (LUSC) has been recognized as the most common pathological form of lung cancer. The comprehensive understanding of molecular features related to LUSC progression has great significance in LUSC prognosis assessment and clinical management. In this study, we aim to identify a panel of signature genes closely associated with LUSC, which can provide novel insights into the progression of LUSC. Gene expression profiles were retrieved from public resources including gene expression omnibus (GEO) and the cancer genome atlas (TCGA) database. Differentially expressed genes (DEGs) between LUSC specimens and normal lung tissues were identified by bioinformatics analyses. A total of 66 DEGs were identified based on two cohorts of data. CytoHubba plugin of Cytoscape software was utilized for the further analyses of the top 10 candidate hub genes including OGN, ABI3BP, MAMDC2, FGF7, FAM107A, SPARCL1, DCN, COL14A1, and MFAP4 and CHRDL1, which showed significant downregulation in LUSC. Two LUSC cell lines were used to validate the functions of CHRDL1 and FAM107A through overexpression experiment. Together, our data revealed novel candidate tumor-suppressor genes in LUSC, suggesting previously unappreciated mechanisms in the progression of LUSC.

The role of radiotherapy-related autophagy genes in the prognosis and immune infiltration in lung adenocarcinoma

Background

There is a close relationship between radiotherapy and autophagy in tumors, but the prognostic role of radiotherapy-related autophagy genes (RRAGs) in lung adenocarcinoma (LUAD) remains unclear.

Methods

Data used in the current study were extracted from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Weighted gene co-expression network analysis (WGCNA) was executed to recognize module genes associated with radiotherapy. The differentially expressed genes (DEGs) between different radiotherapy response groups were filtered via edgeR package. The differentially expressed radiotherapy-related autophagy genes (DERRAGs) were obtained by overlapping the module genes, DEGs, and autophagy genes (ATGs). Then, prognostic autophagy genes were selected by Cox analyses, and a risk model and nomogram were subsequently built. Gene Set Enrichment Analysis (GSEA) and single-sample Gene Set Enrichment Analysis (ssGSEA) were performed to investigate potential mechanisms through which prognostic autophagy signatures regulate LUAD. Radiotherapy-resistant cell lines (A549IR and PC9IR) were established after exposure to hypo-fractionated irradiation. Ultimately, mRNA expression was validated by quantitative real-time PCR (qRT-PCR), and relative protein levels were measured in different cell lines by western blot.

Results

A total of 11 DERRAGs were identified in LUAD. After Cox analyses, SHC1, NAPSA, and AURKA were filtered as prognostic signatures in LUAD. Then, the risk score model was constructed using the prognostic signatures, which had a good performance in predicting the prognosis, as evidenced by receiver operating characteristics curves. Furthermore, Cox regression analyses demonstrated that risk score was deemed as an independent prognostic factor in LUAD. Moreover, GSEA and ssGSEA results revealed that prognostic RRAGs may regulate LUAD by modulating the immune microenvironment and affecting cell proliferation. The colony formation assay showed that the radiosensitivity of radiation-resistant cell lines was lower than that of primary cells. The western blot assay found that the levels of autophagy were elevated in the radiotherapy-resistant cell lines. Moreover, the expression of DERRAGs (SHC1, AURKA) was higher in the radiotherapy-resistant cells than in primary cells.

Conclusion

Our study explored the role of RRAGs in the prognosis of LUAD and identified three biomarkers. The findings enhanced the understanding of the relationship between radiotherapy, autophagy, and prognosis in LUAD and provided potential therapeutic targets for LUAD patients.

Identifying General Tumor and Specific Lung Cancer Biomarkers by Transcriptomic Analysis

The bioinformatic pipeline previously developed in our research laboratory is used to identify potential general and specific deregulated tumor genes and transcription factors related to the establishment and progression of tumoral diseases, now comparing lung cancer with other two types of cancer. Twenty microarray datasets were selected and analyzed separately to identify hub differentiated expressed genes and compared to identify all the deregulated genes and transcription factors in common between the three types of cancer and those unique to lung cancer. The winning DEGs analysis allowed to identify an important number of TFs deregulated in the majority of microarray datasets, which can become key biomarkers of general tumors and specific to lung cancer. A coexpression network was constructed for every dataset with all deregulated genes associated with lung cancer, according to DAVID’s tool enrichment analysis, and transcription factors capable of regulating them, according to oPOSSUM´s tool. Several genes and transcription factors are coexpressed in the networks, suggesting that they could be related to the establishment or progression of the tumoral pathology in any tissue and specifically in the lung. The comparison of the coexpression networks of lung cancer and other types of cancer allowed the identification of common connectivity patterns with deregulated genes and transcription factors correlated to important tumoral processes and signaling pathways that have not been studied yet to experimentally validate their role in lung cancer. The Kaplan–Meier estimator determined the association of thirteen deregulated top winning transcription factors with the survival of lung cancer patients. The coregulatory analysis identified two top winning transcription factors networks related to the regulatory control of gene expression in lung and breast cancer. Our transcriptomic analysis suggests that cancer has an important coregulatory network of transcription factors related to the acquisition of the hallmarks of cancer. Moreover, lung cancer has a group of genes and transcription factors unique to pulmonary tissue that are coexpressed during tumorigenesis and must be studied experimentally to fully understand their role in the pathogenesis within its very complex transcriptomic scenario. Therefore, the downstream bioinformatic analysis developed was able to identify a coregulatory metafirm of cancer in general and specific to lung cancer taking into account the great heterogeneity of the tumoral process at cellular and population levels.

Identification of a novel anticancer mechanism of Paeoniae Radix extracts based on systematic transcriptome analysis

Paeoniae Radix (PR) has a great therapeutic value in many clinical applications; however, the presence of various bioactive compounds and its complicated effects on human health makes its precise mechanisms of action unclear. This study investigated the effects of PR at the molecular pathway level by profiling genome-wide gene expression changes following dose-dependent treatment of human lung cancer cells (A549) with PR water extract (WPR), PR ethanol extracts (EPR), as well as their individual components. We found that PR exerts anticancer effects in A549 cells by regulating numerous pathways. Specifically, EPR and two compounds, namely, hederagenin (HG) and oleanolic acid (OA), significantly downregulate the Aurora B pathway. Furthermore, we generated an integrated PR extracts-compounds-target genes network in the Aurora B pathway to understand their interactions. Our findings reinforce that inhibiting Aurora kinase activity is a therapeutic target for treating cancers, providing the potential for novel mechanisms of action for PR and its components against lung cancer.

Mitotic protein kinase-driven crosstalk of machineries for mitosis and metastasis

Accumulating evidence indicates that mitotic protein kinases are involved in metastatic migration as well as tumorigenesis. Protein kinases and cytoskeletal proteins play a role in the efficient release of metastatic cells from a tumor mass in the tumor microenvironment, in addition to playing roles in mitosis. Mitotic protein kinases, including Polo-like kinase 1 (PLK1) and Aurora kinases, have been shown to be involved in metastasis in addition to cell proliferation and tumorigenesis, depending on the phosphorylation status and cellular context. Although the genetic programs underlying mitosis and metastasis are different, the same protein kinases and cytoskeletal proteins can participate in both mitosis and cell migration/invasion, resulting in migratory tumors. Cytoskeletal remodeling supports several cellular events, including cell division, movement, and migration. Thus, understanding the contributions of cytoskeletal proteins to the processes of cell division and metastatic motility is crucial for developing efficient therapeutic tools to treat cancer metastases. Here, we identify mitotic kinases that function in cancer metastasis as well as tumorigenesis. Several mitotic kinases, namely, PLK1, Aurora kinases, Rho-associated protein kinase 1, and integrin-linked kinase, are considered in this review, as an understanding of the shared machineries between mitosis and metastasis could be helpful for developing new strategies to treat cancer.

Improving understanding of the mechanisms linking cell division and cancer spread (metastasis) could provide novel strategies for treatment. A group of enzymes involved in cell division (mitosis) are also thought to play critical roles in the spread of cancers. Hyungshin Yim at Hanyang University in Ansan, South Korea, and co-workers in Korea and the USA reviewed the roles of several mitotic enzymes that are connected with metastasis as well as tumorigenesis. They discussed how these enzymes modify cytoskeletal proteins and other substrates during cancer progression. Some regulatory control of cell cytoskeletal structures is required for cancer cells to metastasize. Recent research has uncovered crosstalk between mitotic enzymes and metastatic cytoskeletal molecules in various cancers. Targeting mitotic enzymes and the ways they influence cytoskeletal mechanisms could provide valuable therapeutic strategies for suppressing metastasis.

ZNF655 Promotes the Progression of Glioma Through Transcriptional Regulation of AURKA

Objectives

Glioma has a high degree of malignancy, strong invasiveness, and poor prognosis, which is always a serious threat to human health. Previous studies have reported that C2H2 zinc finger (ZNF) protein is involved in the progression of various cancers. In this study, the clinical significance, biological behavior, and molecule mechanism of ZNF655 in glioma were explored.

Methods

The expression of ZNF655 in glioma and its correlation with prognosis were analyzed through public datasets and immunohistochemical (IHC) staining. The shRNA-mediated ZNF655 knockdown was used to explore the effects of ZNF655 alteration on the phenotypes and tumorigenesis of human glioma cell lines. Chromatin immunoprecipitation (ChIP)-qPCR and luciferase reporter assays were performed to determine the potential mechanism of ZNF655 regulating Aurora kinase A (AURKA).

Results

ZNF655 was abundantly expressed in glioma tissue and cell lines SHG-44 and U251. Knockdown of suppressed the progression of glioma cells, which was characterized by reduced proliferation, enhanced apoptosis, cycle repression in G2, inhibition of migration, and weakened tumorigenesis. Mechanistically, transcription factor ZNF655 activated the expression of AURKA by directly binding to the promoter of AURKA. In addition, downregulation of AURKA partially reversed the promoting effects of overexpression of ZNF655 on glioma cells.

Conclusions

ZNF655 promoted the progression of glioma by binding to the promoter of AURKA, which may be a promising target for molecular therapy.

Selective Inhibition of Aurora Kinase A by AK-01/LY3295668 Attenuates MCC Tumor Growth by Inducing MCC Cell Cycle Arrest and Apoptosis

Merkel cell carcinoma (MCC) is an often-lethal skin cancer with increasing incidence and limited treatment options. Although immune checkpoint inhibitors (ICI) have become the standard of care in advanced MCC, 50% of all MCC patients are ineligible for ICIs, and amongst those treated, many patients develop resistance. There is no therapeutic alternative for these patients, highlighting the urgent clinical need for alternative therapeutic strategies. Using patient-derived genetic insights and data generated in our lab, we identified aurora kinase as a promising therapeutic target for MCC. In this study, we examined the efficacy of the recently developed and highly selective AURKA inhibitor, AK-01 (LY3295668), in six patient-derived MCC cell lines and two MCC cell-line-derived xenograft mouse models. We found that AK-01 potently suppresses MCC survival through apoptosis and cell cycle arrest, particularly in MCPyV-negative MCC cells without RB expression. Despite the challenge posed by its short in vivo durability upon discontinuation, the swift and substantial tumor suppression with low toxicity makes AK-01 a strong potential candidate for MCC management, particularly in combination with existing regimens.

ISL1 promoted tumorigenesis and EMT via Aurora kinase A-induced activation of PI3K/AKT signaling pathway in neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid malignancy in children and its mortality rate is relatively high. However, driver genes of NB are not clearly identified. Using bioinformatics analysis, we determined the top 8 differentially expressed genes (DEGs) in NB, including GFAP, PAX6, FOXG1, GAD1, PTPRC, ISL1, GRM5, and GATA3. Insulin gene enhancer binding protein 1 (ISL1) is a LIM homeodomain transcription factor which has been found to be highly expressed in a variety of malignant tumors, but the function of ISL1 in NB has not been fully elucidated. We identified ISL1 as an oncogene in NB. ISL1 is preferentially upregulated in NB tissues compared with normal tissues. High ISL1 expression is significantly associated with poor outcome of NB patients. Knockdown of ISL1 markedly represses proliferation and induces cell apoptosis in vitro, and suppresses tumorigenicity in vivo, while overexpression of ISL1 has the opposite effects. Mechanistically, we demonstrate that ISL1 promotes cell proliferation and EMT transformation through PI3K/AKT signaling pathway by upregulating Aurora kinase A (AURKA), a serine-threonine kinase that is essential for the survival of NB cells. The blockade of AURKA attenuates the function of ISL1 overexpression in the regulation of cell proliferation and migration, Conclusively, this study showed that ISL1 targeted AURKA to facilitate the development of NB, which provided new insights into the tumorigenesis of NB. Thus, ISL1 may be a promising therapeutic target in the future.

Identification of potential hub genes associated with the pathogenesis and prognosis of hepatocellular carcinoma via integrated bioinformatics analysis

Objective

The objective was to identify potential hub genes associated with the pathogenesis and prognosis of hepatocellular carcinoma (HCC).

Methods

Gene expression profile datasets were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between HCC and normal samples were identified via an integrated analysis. A protein–protein interaction network was constructed and analyzed using the STRING database and Cytoscape software, and enrichment analyses were carried out through DAVID. Gene Expression Profiling Interactive Analysis and Kaplan–Meier plotter were used to determine expression and prognostic values of hub genes.

Results

We identified 11 hub genes (CDK1, CCNB2, CDC20, CCNB1, TOP2A, CCNA2, MELK, PBK, TPX2, KIF20A, and AURKA) that might be closely related to the pathogenesis and prognosis of HCC. Enrichment analyses indicated that the DEGs were significantly enriched in metabolism-associated pathways, and hub genes and module 1 were highly associated with cell cycle pathway.

Conclusions

In this study, we identified key genes of HCC, which indicated directions for further research into diagnostic and prognostic biomarkers that could facilitate targeted molecular therapy for HCC.

Aurora kinase inhibitors as potential anticancer agents: Recent advances

Aurora kinases are a family of serine/threonine kinases that play a crucial role in cell proliferation through the regulation of mitotic spindles. These kinases are the regulatory proteins localized in the various phases of the cell cycle and are involved in centrosome maturation, chromosome alignment, chromosomal segregation, and cytokinesis. They have emerged as one of the validated drug targets for anticancer drug discovery as their overexpression has been implicated in the pathogenesis of various carcinomas. Inhibitors of Aurora kinases induce growth inhibition and apoptosis in a variety of tumor cells. Hence, the design and development of Aurora kinase inhibitors have been widely explored in recent years by the scientific community as potential anticancer agents. Various Aurora kinase inhibitors have been under preclinical and clinical investigations as antitumor agents. This review summarizes the recent strategies of various researchers for the design and development of Aurora kinase inhibitors belonging to different structural classes. Their bioactivity, SARs, molecular modelling, and mechanistic studies have also been described. The comprehensive compilation of research work carried out in the field will provide inevitable scope for the design and development of novel drug candidates with better selectivity and efficacy. The review is constructed after the exhaustive research in this discipline and includes the papers from 2011 to 2020.

Promising Therapy in Lung Cancer: Spotlight on Aurora Kinases

Simple Summary

Lung cancer has remained one of the major causes of death worldwide. Thus, a more effective treatment approach is essential, such as the inhibition of specific cancer-promoting molecules. Aurora kinases regulate the process of mitosis—a process of cell division that is necessary for normal cell proliferation. Dysfunction of these kinases can contribute to cancer formation. In this review, we present studies indicating the implication of Aurora kinases in tumor formation, drug resistance, and disease prognosis. The effectivity of using Aurora kinase inhibitors in the pre-clinical and clinical investigations has proven their therapeutic potential in the setting of lung cancer. This work may provide further information to broaden the development of anticancer drugs and, thus, improve the conventional lung cancer management.

Abstract

Despite tremendous efforts to improve the treatment of lung cancer, prognosis still remains poor; hence, the search for efficacious therapeutic option remains a prime concern in lung cancer research. Cell cycle regulation including mitosis has emerged as an important target for cancer management. Novel pharmacological agents blocking the activities of regulatory molecules that control the functional aspects of mitosis such as Aurora kinases are now being investigated. The Aurora kinases, Aurora-A (AURKA), and Aurora B (AURKB) are overexpressed in many tumor entities such as lung cancer that correlate with poor survival, whereby their inhibition, in most cases, enhances the efficacy of chemo-and radiotherapies, indicating their implication in cancer therapy. The current knowledge on Aurora kinase inhibitors has increasingly shown high potential in ensuing targeted therapies in lung malignancies. In this review, we will briefly describe the biology of Aurora kinases, highlight their oncogenic roles in the pre-clinical and clinical studies in lung cancer and, finally, address the challenges and potentials of Aurora kinases to improve the therapy of this malignancy.

Synthetic lethality of RB1 and aurora A is driven by stathmin-mediated disruption of microtubule dynamics

RB1 mutational inactivation is a cancer driver in various types of cancer including lung cancer, making it an important target for therapeutic exploitation. We performed chemical and genetic vulnerability screens in RB1-isogenic lung cancer pair and herein report that aurora kinase A (AURKA) inhibition is synthetic lethal in RB1-deficient lung cancer. Mechanistically, RB1^−/− cells show unbalanced microtubule dynamics through E2F-mediated upregulation of the microtubule destabilizer stathmin and are hypersensitive to agents targeting microtubule stability. Inhibition of AURKA activity activates stathmin function via reduced phosphorylation and facilitates microtubule destabilization in RB1^−/− cells, heavily impacting the bipolar spindle formation and inducing mitotic cell death selectively in RB1^−/− cells. This study shows that stathmin-mediated disruption of microtubule dynamics is critical to induce synthetic lethality in RB1-deficient cancer and suggests that upstream factors regulating microtubule dynamics, such as AURKA, can be potential therapeutic targets in RB1-deficient cancer.

Retinoblastoma susceptibility gene (RB1) is frequently mutated in lung cancers. Here the authors perform chemical and genetic vulnerability screens and identify aurora A kinase (AURKA) as a synthetic lethal candidate for RB1-deficient lung cancer cells and that AURKA inhibition sensitizes these cells to mitotic cell death.

Advances in targeting acquired resistance mechanisms to epidermal growth factor receptor tyrosine kinase inhibitors

Next-generation sequencing (NGS) of tumor samples and circulating tumor DNA has revolutionized diagnostic and therapeutic strategies in lung cancer. The identification of the epidermal growth factor receptor (EGFR) oncogenic driver has translated into successful therapy of advanced lung cancer using EGFR tyrosine kinase inhibitors (TKI). Unfortunately, responses are limited by acquired mechanisms of resistance. We review herein the current landscape of acquired resistance mechanisms to EGFR-TKI therapy and recent advances in therapeutic strategies to overcome acquired resistance.

Inhibition of Aurora A enhances radiosensitivity in selected lung cancer cell lines

Background

In mammalian cells, Aurora serine/threonine kinases (Aurora A, B, and C) are expressed in a cell cycle-dependent fashion as key mitotic regulators required for the maintenance of chromosomal stability. Aurora-A (AURKA) has been proven to be an oncogene in a variety of cancers; however, whether its expression relates to patient survival and the association with radiotherapy remains unclear in non-small cell lung cancer (NSCLC).

Methods

Here, we first analyzed AURKA expression in 63 NSCLC tumor samples by immunohistochemistry (IHC) and used an MTS assay to compare cell survival by targeting AURKA with MLN8237 (Alisertib) in H460 and HCC2429 (P53-competent), and H1299 (P53-deficient) cell lines. The radiosensitivity of MLN8237 was further evaluated by clonogenic assay. Finally, we examined the effect of combining radiation and AURKA inhibition in vivo with a xenograft model and explored the potential mechanism.

Results

We found that increased AURKA expression correlated with decreased time to progression and overall survival (p = 0.0447 and 0.0096, respectively). AURKA inhibition using 100 nM MLN8237 for 48 h decreases cell growth in a partially P53-dependent manner, and the survival rates of H460, HCC2429, and H1299 cells were 56, 50, and 77%, respectively. In addition, the survival of H1299 cells decreased 27% after ectopic restoration of P53 expression, and the radiotherapy enhancement was also influenced by P53 expression (DER H460 = 1.33; HCC2429 = 1.35; H1299 = 1.02). Furthermore, tumor growth of H460 was delayed significantly in a subcutaneous mouse model exposed to both MLN8237 and radiation.

Conclusions

Taken together, our results confirmed that the expression of AURKA correlated with decreased NSCLC patient survival, and it might be a promising inhibition target when combined with radiotherapy, especially for P53-competent lung cancer cells. Modulation of P53 function could provide a new option for reversing cell resistance to the AURKA inhibitor MLN8237, which deserves further investigation.

Identification of key biomarkers and potential molecular mechanisms in lung cancer by bioinformatics analysis

Lung cancer is one of the most widespread neoplasms worldwide. To identify the key biomarkers in its carcinogenesis and development, the mRNA microarray datasets GSE102287, GSE89047, GSE67061 and GSE74706 were obtained from the Gene Expression Omnibus database. GEO2R was used to identify the differentially expressed genes (DEGs) in lung cancer. The Database for Annotation, Visualization and Integrated Discovery was used to analyze the functions and pathways of the DEGs, while the Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape were used to obtain the protein-protein interaction (PPI) network. Kaplan Meier curves were used to analyze the effect of the hub genes on overall survival (OS). Module analysis was completed using Molecular Complex Detection in Cytoscape, and one co-expression network of these significant genes was obtained with cBioPortal. A total of 552 DEGs were identified among the four microarray datasets, which were mainly enriched in 'cell proliferation', 'cell growth', 'cell division', 'angiogenesis' and 'mitotic nuclear division'. A PPI network, composed of 44 nodes and 886 edges, was constructed, and its significant module had 16 hub genes in the whole network: Opa interacting protein 5, exonuclease 1, PCNA clamp-associated factor, checkpoint kinase 1, hyaluronan-mediated motility receptor, maternal embryonic leucine zipper kinase, non-SMC condensin I complex subunit G, centromere protein F, BUB1 mitotic checkpoint serine/threonine kinase, cyclin A2, thyroid hormone receptor interactor 13, TPX2 microtubule nucleation factor, nucleolar and spindle associated protein 1, kinesin family member 20A, aurora kinase A and centrosomal protein 55. Survival analysis of these hub genes revealed that they were markedly associated with poor OS in patients with lung cancer. In summary, the hub genes and DEGs delineated in the research may aid the identification of potential targets for diagnostic and therapeutic strategies in lung cancer.

The anticancer effects of cinobufagin on hepatocellular carcinoma Huh‑7 cells are associated with activation of the p73 signaling pathway

The Na⁺/K⁺-ATPase inhibitor cinobufagin exhibits numerous anticancer effects on hepatocellular carcinoma (HCC) cells expressing wild-type p53 via inhibition of aurora kinase A (AURKA) and activation of p53 signaling. However, the effects of cinobufagin on HCC cells expressing mutant p53 remain unclear. In the present study, the anticancer effects of cinobufagin were investigated on HCC Huh-7 cells with mutant p53, and the effects of AURKA overexpression or inhibition on the anticancer effects of cinobufagin were analyzed. Viability, cell cycle progression and apoptosis of cells were determined using an MTT assay, flow cytometry and Hoechst 33342 staining, respectively. The expression levels of p53 and p73 signaling-associated proteins were investigated via western blot analysis. The results demonstrated that the expression levels of AURKA, B-cell lymphoma 2 (Bcl-2), cyclin-dependent kinase 1, cyclin B1, proliferating cell nuclear antigen and heterogeneous nuclear ribonucleoprotein K, as well as the phosphorylation of p53 and mouse double minute 2 homolog, were significantly decreased in Huh-7 cells treated with 5 µmol/l cinobufagin for 24 h. Conversely, the expression levels of Bcl-2-associated X protein, p21, p53 upregulated modulator of apoptosis and phorbol-12-myristate-13-acetate-induced protein 1, were significantly increased by cinobufagin treatment. Overexpression or inhibition of AURKA suppressed or promoted the anticancer effects of cinobufagin on Huh-7 cells, respectively. These results indicated that cinobufagin may induce anticancer effects on Huh-7 cells via the inhibition of AURKA and p53 signaling, and via the activation of p73 signaling, in an AURKA-dependent manner.

Effects of Repeated Aurora-A siRNA Transfection on Cilia Generation and Proliferation of SK-MES-1 or A549 Cells

BACKGROUND

Suppression of Aurora kinase A (Aurora-A, AURKA) by siRNA of Aurora-A (siAurora-A, siA) has been used in lung tumor treatment. However, the dose and frequency of gene transfection still need to be confirmed further. We imitated multiple administration of solid tumor and attempted to make out the effects of thrice transfection of siAurora-A on cilia generation and apoptosis of SK-MES-1 cells (SK) or A549 cells.

METHODS

The Aurora-A mRNA levels of cells cultured with serum for 6 d or without serum for 2, 4, or 6 d were examined with real-time quantitative PCR; Cells were transfected single or repeatedly with siAurora-A or siControl (siC), their Aurora-A mRNA levels were determined with PCR; Their cilia were examined with immunohistochemistry. Cell viability was measured with the MTT assay. Protein expression was analyzed with western blot.

RESULTS

Cell viability showed a downward trend along with the prolongation of starvation time to the second, fourth, and even to the sixth day in both types of cells. But, the expression level of Aurora-A mRNA flipped to rise at the sixth day instead of decreasing at the fourth day. Protein expression trend of total Aurora-A in the two groups was consistent with Aurora-A mRNA expression trend. Compared with siC-3 group (transfected three times with siControl), siAurora-A significantly reduced the Aurora-A mRNA expression in siA-3 group (transfected three times with siAurora-A). Similarly, the cell viability of siA-3 group was lower than that of siC-3 group. The cell viability of siC-3 group was higher than that of serum-free-6d group, but, levels of Aurora-A mRNA expression of siC-3 group had no difference with serum-free-6d group. Finally, among groups transfected once or three times or starved for 6 d, there was no significant difference of ciliated cell proportions in both types of cells respectively.

CONCLUSIONS

Repeated siAurora-A transfection decreased Aurora-A expression that resulted in effective suppression proliferation of SK-MES-1 or A549 cells, but did not affect cilia generation.

Targeting AURKA-CDC25C axis to induce synthetic lethality in ARID1A-deficient colorectal cancer cells

ARID1A, a component of the SWI/SNF chromatin remodeling complex, is a tumor suppressor with a high frequency of inactivating mutations in many cancers. Therefore, ARID1A deficiency has been exploited therapeutically for treating cancer. Here we show that ARID1A has a synthetic lethal interaction with aurora kinase A (AURKA) in colorectal cancer (CRC) cells. Pharmacological and genetic perturbations of AURKA selectively inhibit the growth of ARID1A-deficient CRC cells. Mechanistically, ARID1A occupies the AURKA gene promoter and negatively regulates its transcription. Cells lacking ARID1A show enhanced AURKA transcription, which leads to the persistent activation of CDC25C, a key protein for G2/M transition and mitotic entry. Inhibiting AURKA activity in ARID1A-deficient cells significantly increases G2/M arrest and induces cellular multinucleation and apoptosis. This study shows a novel synthetic lethality interaction between ARID1A and AURKA and indicates that pharmacologically inhibiting the AURKA-CDC25C axis represents a novel strategy for treating CRC with ARID1A loss-of-function mutations.

G2/M inhibitors as pharmacotherapeutic opportunities for glioblastoma: the old, the new, and the future

Glioblastoma (GBM) is one of the deadliest tumors and has a median survival of 3 months if left untreated. Despite advances in rationally targeted pharmacological approaches, the clinical care of GBM remains palliative in intent. Since the majority of altered signaling cascades involved in cancer establishment and progression eventually affect cell cycle progression, an alternative approach for cancer therapy is to develop innovative compounds that block the activity of crucial molecules needed by tumor cells to complete cell division. In this context, we review promising ongoing and future strategies for GBM therapeutics aimed towards G2/M inhibition such as anti-microtubule agents and targeted therapy against G2/M regulators like cyclin-dependent kinases, Aurora inhibitors, PLK1, BUB, 1, and BUBR1, and survivin. Moreover, we also include investigational agents in the preclinical and early clinical settings. Although several drugs were shown to be gliotoxic, most of them have not yet entered therapeutic trials. The use of either single exposure or a combination with novel compounds may lead to treatment alternatives for GBM patients in the near future.

Non-small-cell lung cancer pathological subtype-related gene selection and bioinformatics analysis based on gene expression profiles

Lung cancer is one of the most common malignant diseases and a major threat to public health on a global scale. Non-small-cell lung cancer (NSCLC) has a higher degree of malignancy and a lower 5-year survival rate compared with that of small-cell lung cancer. NSCLC may be mainly divided into two pathological subtypes, adenocarcinoma and squamous cell carcinoma. The aim of the present study was to identify disease genes based on the gene expression profile and the shortest path analysis of weighted functional protein association networks with the existing protein-protein interaction data from the Search Tool for the Retrieval of Interacting Genes. The gene expression profile (GSE10245) was downloaded from the National Center for Biotechnology Information Gene Expression Omnibus database, including 40 lung adenocarcinoma and 18 lung squamous cell carcinoma tissues. A total of 8 disease genes were identified using Naïve Bayesian Classifier based on the Maximum Relevance Minimum Redundancy feature selection method following preprocessing. An additional 21 candidate genes were selected using the shortest path analysis with Dijkstra's algorithm. The AURKA and SLC7A2 genes were selected three and two times in the shortest path analysis, respectively. All those genes participate in a number of important pathways, such as oocyte meiosis, cell cycle and cancer pathways with Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. The present findings may provide novel insights into the pathogenesis of NSCLC and enable the development of novel therapeutic strategies. However, further investigation is required to confirm these findings.

Network analysis revealed aurora kinase dysregulation in five gynecological types of cancer

Gene markers are crucial for cancer prognosis and treatment. Previous studies have placed greater emphasis on individual diagnostic genes, thereby ignoring systemic-level attributes across diseases. Female-specific cells namely, breast, endometrium, cervical, ovarian and vulvar cells are highly susceptible to cancer. To date, a limited number of molecular studies have been performed that evaluate common biological processes across gynecological types of cancer. Differentially expressed genes in breast, cervical, endometrial, vulvar and ovarian cancer were utilized to construct protein-protein interaction networks, and to identify a common module across the five cancer types. A single common module with 8 nodes and 26 edges was mined among the five cancer systems. In total, four hub genes were present across the five cancer gene sets. Genes in the common module were enriched for the common pathways and associated diseases. The aurora kinase pathway was revealed to be conserved across the five cancer types surveyed. The present study, therefore, revealed that the aurora kinase pathway has a crucial function in the pathogenesis of the five aforementioned gynecological types of cancer through cross-tumor conservation.

Aurora kinases: novel therapy targets in cancers

Aurora kinases, a family of serine/threonine kinases, consisting of Aurora A (AURKA), Aurora B (AURKB) and Aurora C (AURKC), are essential kinases for cell division via regulating mitosis especially the process of chromosomal segregation. Besides regulating mitosis, Aurora kinases have been implicated in regulating meiosis. The deletion of Aurora kinases could lead to failure of cell division and impair the embryonic development. Overexpression or gene amplification of Aurora kinases has been clarified in a number of cancers. And a growing number of studies have demonstrated that inhibition of Aurora kinases could potentiate the effect of chemotherapies. For the past decades, a series of Aurora kinases inhibitors (AKIs) developed effectively repress the progression and growth of many cancers both in vivo and in vitro, suggesting that Aurora kinases could be a novel therapeutic target. In this review, we'll first briefly present the structure, localization and physiological functions of Aurora kinases in mitosis, then describe the oncogenic role of Aurora kinases in tumorigenesis, we shall finally discuss the outcomes of AKIs combination with conventional therapy.

Aurora-A-mediated phosphorylation of LKB1 compromises LKB1/AMPK signaling axis to facilitate NSCLC growth and migration

Deletion or loss-of-function mutation of LKB1, frequently occurring in non-small cell lung cancers (NSCLCs), is a predominant caution of NSCLC initiation and progression. However, the upstream signaling pathways governing LKB1 activation are largely unknown. Here, we report that LKB1 undergoes Aurora kinase A (AURKA)-mediated phosphorylation, which largely compromises the LKB1/AMPK signaling axis, in turn leading to the elevation of NSCLC cell proliferation, invasion and migration. Mechanically, AURKA-mediated phosphorylation of LKB1 impairs LKB1 interaction with and phosphorylation of its downstream target AMPKα, which has critical roles in governing cancer cell energy metabolic homeostasis and tumorigenesis. Clinically, AURKA displays high levels in NSCLC patients, and correlates with poor outcome of patients with lung adenocarcinoma. Pathologically, the amplification or activation of AURKA-induced impairment of the LKB1/AMPK signaling pathway contributes to NSCLC initiation and progression, highlighting AURKA as a potential therapeutic target for combatting hyperactive AURKA-driven NSCLCs.

AURKA mRNA expression is an independent predictor of poor prognosis in patients with non-small cell lung cancer

Deregulation of mitotic spindle genes has been reported to contribute to the development and progression of malignant tumours. The aim of the present study was to explore the association between the expression profiles of Aurora kinases (AURKA, AURKB and AURKC), cytoskeleton-associated protein 5 (CKAP5), discs large-associated protein 5 (DLGAP5), kinesin-like protein 11 (KIF11), microtubule nucleation factor (TPX2), monopolar spindle 1 kinase (TTK), and β-tubulins (TUBB) and (TUBB3) genes and clinicopathological characteristics in human non-small cell lung carcinoma (NSCLC). Reverse transcription-quantitative polymerase chain reaction-based RNA gene expression profiles of 132 NSCLC and 44 adjacent wild-type tissues were generated, and Cox's proportional hazard regression was used to examine associations. With the exception of AURKC, all genes exhibited increased expression in NSCLC tissues. Of the 10 genes examined, only AURKA was significantly associated with prognosis in NSCLC. Multivariate Cox's regression analysis demonstrated that AURKA mRNA expression [hazard ratio (HR), 1.81; 95% confidence interval (CI), 1.16-2.84; P=0.009], age (HR, 1.03; 95% CI, 1.00-1.06; P=0.020), pathological tumour stage 2 (HR, 2.43; 95% CI, 1.16-5.10; P=0.019) and involvement of distal nodes (pathological node stage 2) (HR, 3.14; 95% CI, 1.24-7.99; P=0.016) were independent predictors of poor prognosis in patients with NSCLC. Poor prognosis of patients with increased AURKA expression suggests that those patients may benefit from surrogate therapy with AURKA inhibitors.

Domain-specific interactions between MLN8237 and human serum albumin estimated by STD and WaterLOGSY NMR, ITC, spectroscopic, and docking techniques

Alisertib (MLN8237) is an orally administered inhibitor of Aurora A kinase. This small-molecule inhibitor is under clinical or pre-clinical phase for the treatment of advanced malignancies. The present study provides a detailed characterization of the interaction of MLN8237 with a drug transport protein called human serum albumin (HSA). STD and WaterLOGSY nuclear magnetic resonance (NMR)-binding studies were conducted first to confirm the binding of MLN8237 to HSA. In the ligand orientation assay, the binding sites of MLN8237 were validated through two site-specific spy molecules (warfarin sodium and ibuprofen, which are two known site-selective probes) by using STD and WaterLOGSY NMR competition techniques. These competition experiments demonstrate that both spy molecules do not compete with MLN8237 for the specific binding site. The AutoDock-based blind docking study recognizes the hydrophobic subdomain IB of the protein as the probable binding site for MLN8237. Thermodynamic investigations by isothermal titration calorimetry (ITC) reveal that the non-covalent interaction between MLN8237 and HSA (binding constant was approximately 10⁵ M⁻¹) is driven mainly by favorable entropy and unfavorable enthalpy. In addition, synchronous fluorescence, circular dichroism (CD), and 3D fluorescence spectroscopy suggest that MLN8237 may induce conformational changes in HSA.

AURKA promotes cancer metastasis by regulating epithelial-mesenchymal transition and cancer stem cell properties in hepatocellular carcinoma

AURKA (aurora kinase A) has been confirmed as an oncogene in cancer development; however, its role and underlying mechanisms in the metastasis of hepatocellular carcinoma (HCC) remain unknown. In this study, We found that AURKA was up-regulated in HCC tissues and correlated with pathological stage and distant metastasis. Further found that AURKA was involved in the cancer metastases after radiation in HCC. While overexpression of AURKA induced epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) behaviors though PI3K/AKT pathway, silencing AURKA suppressed radiation-enhanced cell invasiveness of HCC. Taken together, our results suggested that AURKA contributed in metastasis of irradiated residul HCC though facilitating EMT and CSC properties, suggesting the potential clinical application of AURKA inhibitors in radiotherapy for patients with HCC.

Clinical Development of Anti-mitotic Drugs in Cancer

Mitosis is one of the most fundamental processes of life by which a mammalian cell divides into two daughter cells. Mitosis has been an attractive target for anticancer therapies since fast proliferation was identified as one of the hallmarks of cancer cells. Despite efforts into developing specific inhibitors for mitotic kinases and kinesins, very few drugs have shown the efficiency of microtubule targeting-agents in cancer cells with paclitaxel being the most successful. A deeper translational research accompanying clinical trials of anti-mitotic drugs will help in identifying potent biomarkers predictive for response. Here, we review the current knowledge of mitosis targeting agents that have been tested so far in the clinics.

Combined Cancer Immunotherapy Against Aurora Kinase A

Aurora kinase A (AURKA) is a centrosomal protein that is overexpressed in a number of human malignancies and can contribute to tumor progression. As we used this protein as a target of DNA immunization, we increased its immunogenicity by the addition of the PADRE helper epitope and decreased its potential oncogenicity by mutagenesis of the kinase domain. For in vitro analysis of induced immune responses in mice, we identified the Aurka(220-228) nonapeptide representing an H-2Kb epitope. As DNA vaccination against the Aurka self-antigen by a gene gun did not show any antitumor effect, we combined DNA immunization with anti-CD25 treatment that depletes mainly regulatory T cells. Whereas 1 anti-CD25 dose injected before DNA vaccination did not enhance the activation of Aurka-specific splenocytes, 3 doses administered on days of immunizations augmented about 10-fold immunity against Aurka. However, an opposite effect was found for antitumor immunity-only 1 anti-CD25 dose combined with DNA vaccination reduced tumor growth. Moreover, the administration of 3 doses of anti-CD25 antibody alone accelerated tumor growth. Analysis of tumor-infiltrating cells showed that 3 anti-CD25 doses not only efficiently depleted regulatory T cells but also activated helper T cells and CD3(-)CD25(+) cells. Next, we found that blockade of the PD-1 receptor initiated 1 week after the first immunization was necessary for significant inhibition of tumor growth with therapeutic DNA vaccination against Aurka combined with depletion of CD25 cells. Our results suggest that combined cancer immunotherapy should be carefully evaluated to achieve the optimal antitumor effect.

Effect of Food on the Pharmacokinetics of the Investigational Aurora A Kinase Inhibitor Alisertib (MLN8237) in Patients with Advanced Solid Tumors

Objective

This study was conducted to characterize the effects of food on single-dose pharmacokinetics (PK) of the investigational Aurora A kinase inhibitor alisertib (MLN8237) in patients with advanced solid tumors.

Methods

Following overnight fasting for 10 h, a single 50 mg enteric-coated tablet (ECT) of alisertib was administered under either fasted (alisertib with 240 mL of water) or fed (high-fat meal consumed 30 min before receiving alisertib with 240 mL of water) conditions using a two-cycle, two-way crossover design. Patients on both arms were not allowed food for 4 h post-dose. Water was allowed as desired, except for 1 h before and after alisertib administration.

Results

Twenty-four patients were enrolled and 14 patients were PK-evaluable (ten patients were not PK-evaluable due to insufficient data). Following a single oral dose of alisertib, median t_max was 6 h and 3 h under fed and fasted conditions, respectively. The geometric mean ratio of AUC_inf (fed- vs. fasted-state dosing) was 0.94 [90 % confidence interval (CI) 0.68–1.32]. The geometric mean C_max under fed conditions was 84 % of that under fasted conditions (90 % CI 66–106). Alisertib was generally well-tolerated; most common drug-related grade 3/4 adverse events included neutropenia (50 %), leukopenia (38 %), and thrombocytopenia (21 %).

Conclusions

Systemic exposures achieved following a single 50 mg dose of alisertib administered as an ECT formulation after a high-fat meal are similar to those observed in the fasted state. Alisertib 50 mg ECT can be administered without regard for food.

ClinicalTrials.gov Identifier

NCT00962091.

Using reverse docking to identify potential targets for ginsenosides

Background

Ginsenosides are the main ingredients of ginseng, which, in traditional Eastern medicine, has been claimed to have therapeutic values for many diseases. In order to verify the effects of ginseng that have been empirically observed, we utilized the reverse docking method to screen for target proteins that are linked to specific diseases.

Methods

We constructed a target protein database including 1,078 proteins associated with various kinds of diseases, based on the Potential Drug Target Database, with an added list of kinase proteins. We screened 26 kinds of ginsenosides of this target protein database using docking.

Results

We found four potential target proteins for ginsenosides, based on docking scores. Implications of these “hit” targets are discussed. From this screening, we also found four targets linked to possible side effects and toxicities, based on docking scores.

Conclusion

Our method and results can be helpful for finding new targets and developing new drugs from natural products.

Aurora-A Kinase: A Potent Oncogene and Target for Cancer Therapy

The Aurora kinase family is comprised of three serine/threonine kinases, Aurora-A, Aurora-B, and Aurora-C. Among these, Aurora-A and Aurora-B play central roles in mitosis, whereas Aurora-C executes unique roles in meiosis. Overexpression or gene amplification of Aurora kinases has been reported in a broad range of human malignancies, pointing to their role as potent oncogenes in tumorigenesis. Aurora kinases therefore represent promising targets for anticancer therapeutics. A number of Aurora kinase inhibitors (AKIs) have been generated; some of which are currently undergoing clinical evaluation. Recent studies have unveiled novel unexpected functions of Aurora kinases during cancer development and the mechanisms underlying the anticancer actions of AKIs. In this review, we discuss the most recent advances in Aurora-A kinase research and targeted cancer therapy, focusing on the oncogenic roles and signaling pathways of Aurora-A kinases in promoting tumorigenesis, the recent preclinical and clinical AKI data, and potential alternative routes for Aurora-A kinase inhibition.

Aurora kinase targeting in lung cancer reduces KRAS-induced transformation

BACKGROUND

Activating mutations in KRAS are prevalent in lung cancer and have been causally linked to the oncogenic process. However, therapies targeted to oncogenic RAS have been ineffective to date and identification of KRAS targets that impinge on the oncogenic phenotype is warranted. Based on published studies showing that mitotic kinases Aurora A (AURKA) and B (AURKB) cooperate with oncogenic RAS to promote malignant transformation and that AURKA phosphorylates RAS effector pathway components, the aim of this study was to investigate whether AURKA and AURKB are KRAS targets in lung cancer and whether targeting these kinases might be therapeutically beneficial.

METHODS

In order to determine whether oncogenic KRAS induces Aurora kinase expression, we used qPCR and western blotting in three different lung cell-based models of gain- or loss-of-function of KRAS. In order to determine the functional role of these kinases in KRAS-induced transformation, we generated KRAS-positive A549 and H358 cells with stable and inducible shRNA-mediated knockdown of AURKA or AURKB and evaluated transformation in vitro and tumor growth in vivo. In order to validate AURKA and/or AURKB as therapeutically relevant KRAS targets in lung cancer, we treated A549 and H358 cells, as well as two different lung cell based models of gain-of-function of KRAS with a dual Aurora kinase inhibitor and performed functional in vitro assays.

RESULTS

We determined that KRAS positively regulates AURKA and AURKB expression. Furthermore, in KRAS-positive H358 and A549 cell lines, inducible knockdown of AURKA or AURKB, as well as treatment with a dual AURKA/AURKB inhibitor, decreased growth, viability, proliferation, transformation, and induced apoptosis in vitro. In addition, inducible shRNA-mediated knockdown of AURKA in A549 cells decreased tumor growth in vivo. More importantly, dual pharmacological inhibiton of AURKA and AURKB reduced growth, viability, transformation, and induced apoptosis in vitro in an oncogenic KRAS-dependent manner, indicating that Aurora kinase inhibition therapy can specifically target KRAS-transformed cells.

CONCLUSIONS

Our results support our hypothesis that Aurora kinases are important KRAS targets in lung cancer and suggest Aurora kinase inhibition as a novel approach for KRAS-induced lung cancer therapy.

Suppression of Proinflammatory and Prosurvival Biomarkers in Oral Cancer Patients Consuming a Black Raspberry Phytochemical-Rich Troche

Black raspberries (BRB) demonstrate potent inhibition of aerodigestive tract carcinogenesis in animal models. However, translational clinical trials evaluating the ability of BRB phytochemicals to impact molecular biomarkers in the oral mucosa remain limited. The present phase 0 study addresses a fundamental question for oral cancer food-based prevention: Do BRB phytochemicals successfully reach the targeted oral tissues and reduce proinflammatory and antiapoptotic gene expression profiles? Patients with biopsy-confirmed oral squamous cell carcinomas (OSCC) administered oral troches containing freeze-dried BRB powder from the time of enrollment to the date of curative intent surgery (13.9 ± 1.27 days). Transcriptional biomarkers were evaluated in patient-matched OSCCs and noninvolved high at-risk mucosa (HARM) for BRB-associated changes. Significant expression differences between baseline OSCC and HARM tissues were confirmed using a panel of genes commonly deregulated during oral carcinogenesis. Following BRB troche administration, the expression of prosurvival genes (AURKA, BIRC5, EGFR) and proinflammatory genes (NFKB1, PTGS2) were significantly reduced. There were no BRB-associated grade 3-4 toxicities or adverse events, and 79.2% (N = 30) of patients successfully completed the study with high levels of compliance (97.2%). The BRB phytochemicals cyanidin-3-rutinoside and cyanidin-3-xylosylrutinoside were detected in all OSCC tissues analyzed, demonstrating that bioactive components were successfully reaching targeted OSCC tissues. We confirmed that hallmark antiapoptotic and proinflammatory molecular biomarkers were overexpressed in OSCCs and that their gene expression was significantly reduced following BRB troche administration. As these molecular biomarkers are fundamental to oral carcinogenesis and are modifiable, they may represent emerging biomarkers of molecular efficacy for BRB-mediated oral cancer chemoprevention.

Functional analysis of phosphorylation of the mitotic centromere-associated kinesin by Aurora B kinase in human tumor cells

Mitotic centromere-associated kinesin (MCAK) is the best characterized member of the kinesin-13 family and plays important roles in microtubule dynamics during mitosis. Its activity and subcellular localization is tightly regulated by an orchestra of mitotic kinases, such as Aurora B. It is well known that serine 196 of MCAK is the major phosphorylation site of Aurora B in Xenopus leavis extracts and that this phosphorylation regulates its catalytic activity and subcellular localization. In the current study, we have addressed the conserved phosphorylation site serine 192 in human MCAK to characterize its function in more depth in human cancer cells. Our data confirm that S192 is the major phosphorylation site of Aurora B in human MCAK and that this phosphorylation has crucial roles in regulating its catalytic activity and localization at the kinetochore/centromere region in mitosis. Interfering with this phosphorylation leads to a delayed progression through prometa- and metaphase associated with mitotic defects in chromosome alignment and segregation. We show further that MCAK is involved in directional migration and invasion of tumor cells, and interestingly, interference with the S192 phosphorylation affects this capability of MCAK. These data provide the first molecular explanation for clinical observation, where an overexpression of MCAK was associated with lymphatic invasion and lymph node metastasis in gastric and colorectal cancer patients.

Daurinol Enhances the Efficacy of Radiotherapy in Lung Cancer via Suppression of Aurora Kinase A/B Expression

The aurora kinases constitute one family of serine/threonine kinases whose activity is essential for mitotic progression. The aurora kinases are frequently upregulated in human cancers and are associated with sensitivity to chemotherapy in certain ones. In the present study, we investigated whether aurora kinases could be a target to overcome radioresistance or enhance the radiosensitivity of lung cancer. For that purpose, we determined the therapeutic potential of daurinol, an investigational topoisomerase inhibitor, alone and in combination with radiation, by observing its effect on aurora kinases. Daurinol decreased cell viability and proliferation in human colon and lung cancer cells. Gene expression in daurinol-treated human colon cancer cells was evaluated using RNA microarray. The mRNA expression of 18 genes involved in the mitotic spindle check point, including aurora kinase A (AURKA) and aurora kinase B (AURKB), was decreased in daurinol-treated human colon cancer cells as compared with vehicle-treated cells. As expected, radiation increased expression levels of AURKA and AURKB. This increase was effectively attenuated by siRNAs against AURKA and AURKB, which suppressed cell growth and increased apoptosis under radiation. Furthermore, the expression of AURKA and AURKB was suppressed by daurinol in the presence or absence of radiation in colon and lung cancer cells. Daurinol alone or in combination with radiation decreased lung cancer growth in xenograft mouse models. Our data clearly confirm the antitumor and radiosensitizing activity of daurinol in human lung cancer cells through the inhibition of AURKA and AURKB.

ATF2 contributes to cisplatin resistance in non-small cell lung cancer and celastrol induces cisplatin resensitization through inhibition of JNK/ATF2 pathway

ATF2 is a transcription factor involved in stress and DNA damage. A correlation between ATF2 JNK-mediated activation and resistance to damaging agents has already been reported. The purpose of the present study was to investigate whether ATF2 may have a role in acquired resistance to cisplatin in non-small cell lung cancer (NSCLC). mRNA and protein analysis on matched cancer and corresponding normal tissues from surgically resected NSCLC have been performed. Furthermore, in NSCLC cell lines, ATF2 expression levels were evaluated and correlated to platinum (CDDP) resistance. Celastrol-mediated ATF2/cJUN activity was measured. High expression levels of both ATF2 transcript and proteins were observed in lung cancer specimens (p << 0.01, Log2 (FC) = +4.7). CDDP-resistant NSCLC cell lines expressed high levels of ATF2 protein. By contrast, Celastrol-mediated ATF2/cJUN functional inhibition restored the response to CDDP. Moreover, ATF2 protein activation correlates with worse outcome in advanced CDDP-treated patients. For the first time, it has been shown NSCLC ATF2 upregulation at both mRNA/protein levels in NSCLC. In addition, we reported that in NSCLC cell lines a correlation between ATF2 protein expression and CDDP resistance occurs. Altogether, our results indicate a potential increase in CDDP sensitivity, on Celastrol-mediated ATF2/cJUN inhibition. These data suggest a possible involvement of ATF2 in NSCLC CDDP-resistance.

3,6,2',4',5'-Pentahydroxyflavone, an orally bioavailable multiple protein kinase inhibitor, overcomes gefitinib resistance in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most lethal cancer, causing more than 150,000 deaths in the United States in 2013. The receptor tyrosine kinase inhibitors such as gefitinib are not perfect clinical therapeutic agents for NSCLC treatment due to primary or acquired tyrosine kinase inhibitor resistance. Herein, 3,6,2',4',5'-pentahydroxyflavone (36245-PHF) was identified as a multiple kinase inhibitor for NSCLC treatment based on the computational screening of a natural products database. 36245-PHF was shown to inhibit PI3K and Aurora A and B kinases and overcome gefitinib-resistant NSCLC growth. Our data clearly showed that 36245-PHF markedly inhibited anchorage-independent growth of gefitinib-resistant NSCLC cell lines and exerted a substantial chemotherapeutic effect following oral administration in a gefitinib-resistant NSCLC xenograft model. The evidence from three different subsequent methodological approaches, in vitro, ex vivo, and in vivo, all confirmed that 36245-PHF as a multiple protein kinase inhibitor. Overall, we identified 36245-PHF as a multiple protein kinase inhibitor and as a novel therapeutic agent to overcome gefitinib-resistant NSCLC growth, which could provide a new option for clinical NSCLC oral treatment.

Anticancer activity of the Aurora A kinase inhibitor MK-5108 in non-small-cell lung cancer (NSCLC) in vitro as monotherapy and in combination with chemotherapies

PURPOSE

Aurora kinases are key regulators of mitotic events. Dysfunction of these kinases can cause polyploidy and chromosomal instability, a contributor to tumorigenesis. MK-5108 is a potent inhibitor of Aurora A kinase that has shown preclinical potent activity in malignancies of breast, cervical, colon, ovarian, and pancreatic origin. We sought to assess the preclinical efficacy of MK-5108 in a panel of non-small-cell lung cancer cell lines as a single agent and in combination with cisplatin and docetaxel.

METHODS

Eleven lung cancer cell lines were studied. Growth inhibition by MK-5108 was assessed with short- and long-term MTT assays. Cell cycling was measured by flow cytometry. Immunoblotting was used to determine targeted activity of MK-5108 on Aurora A and downstream effects (TACC3 and Plk1). Efficacy of combination studies performed with cisplatin and docetaxel was evaluated by median effect analysis.

RESULTS

All cell lines demonstrated sustained growth inhibition following MK-5108 at varying nanomolar concentrations. MK-5108 induced G2/M accumulation, polyploidy, and apoptosis (increased sub-G1/PARP cleavage). Levels of Aurora A, TACC3, and Plk1 diminished. Concurrent treatment of MK-5108 with cisplatin or docetaxel synergistically inhibited cell growth with the docetaxel combination performing better. When administered sequentially, treatment with docetaxel first followed by MK-5108 exhibited greater growth inhibition than the inverse; yet concurrent treatment remained superior.

CONCLUSIONS

MK-5108 has potent anti-proliferative activity in lung cancer cell lines alone and in combination with chemotherapies. Determining how best to integrate Aurora inhibitors into current lung cancer treatment regimens would be beneficial.

Frequent T cell responses against immunogenic targets in lung cancer patients for targeted immunotherapy

To date, lung cancer is one of the leading causes of cancer mortality with short overall survival despite adequate therapy. New immunotherapeutic strategies using peptides derived from tumor-associated antigens (TAAs) can induce a specific cytotoxic T cell (CTL) response leading to a targeted tumor cell death. In the present study, we addressed whether there are further significant immunogenic candidate targets that may induce strong immune reactions with a high frequency in lung cancer patients eligible for cellular immunotherapeutic approaches, such as in a polyvalent vaccination approach. In this study, we investigated specific CTL responses of 14 HLA-A*0201-positive patients (of 33 screened patients) with non-small cell lung cancer (NSCLC; n=12) or small cell lung cancer (SCLC; n=2) against several known and novel TAA-derived peptides from lung cancer and/or other tumor entities, by measuring granzyme B (GrB) and/or interferon γ (IFNγ) secretion using enzyme-linked immunospot (ELISpot) analysis. Specific T cell responses could be detected for hTERT (4/13), two MAGE-A3-derived peptides (4/13 and 3/13, respectively), RHAMM (4/14), PRAME (8/14), G250 (7/12), survivin (3/13), HER2 (5/10) and WT1 (2/14), but also novel epitopes derived from Aurora kinase A (4/13) and B (5/13). Additionally, simultaneous CTL responses against the different peptides were examined and specific T cell responses against at least one of these TAAs could be detected in 13/14 (93%) patients. It could be shown that all patients with immune reactions against RHAMM and hTERT showed also immune responses against PRAME. Furthermore, patients with CTL responses against the Aurora kinase A peptide (Aura A1) also demonstrated a response against the Aurora kinase B peptide (Aura B1). Taken together, we showed that these TAA-derived peptides induce frequent specific T cell responses in patients with metastatic lung cancer and are, therefore, novel candidates for targeted immunotherapies and polyvalent approaches.

Aurora A kinase (AURKA) in normal and pathological cell division

Temporally and spatially controlled activation of the Aurora A kinase (AURKA) regulates centrosome maturation, entry into mitosis, formation and function of the bipolar spindle, and cytokinesis. Genetic amplification and mRNA and protein overexpression of Aurora A are common in many types of solid tumor, and associated with aneuploidy, supernumerary centrosomes, defective mitotic spindles, and resistance to apoptosis. These properties have led Aurora A to be considered a high-value target for development of cancer therapeutics, with multiple agents currently in early-phase clinical trials. More recently, identification of additional, non-mitotic functions and means of activation of Aurora A during interphase neurite elongation and ciliary resorption have significantly expanded our understanding of its function, and may offer insights into the clinical performance of Aurora A inhibitors. Here we review the mitotic and non-mitotic functions of Aurora A, discuss Aurora A regulation in the context of protein structural information, and evaluate progress in understanding and inhibiting Aurora A in cancer.

Expression of aurora kinase A and B in chondrosarcoma and its relationship with the prognosis

Purpose

To investigate the expression of Aurora Kinase A and B in patients with chondrosarcoma and consider it as a prognostic marker and molecular target of therapy.

Methods

To evaluate the relationship of the Aurora Kinase A and B and the clinical pathological parameters and prognosis of chondrosarcoma. 72 case chondrosarcoma and 42 case chondroma were performed immunohistochemistry on the tissue microarray paraffin sections. The survival time of patients was followed-up.

Results

The expression of Aurora Kinase A and B in chondrosarcoma was significantly higher than that in chondroma (p<0.01). There were differences about the expression of Aurora Kinase A and B in chondrosarcoma between the recurrence group and the non-recurrence group, metastatic group and non-metastatic group (p<0.05), but not age and gender (p>0.05). The expression of Aurora Kinase A and B were significantly lower in group low grade conventional chondrosarcoma than that in groups medium and high grade conventional chondrosarcoma (p<0.01). The expression of Aurora Kinase A and B in chondrosarcoma showed a positive correlation (p<0.01). According to the Kaplan Meier analysis and multivariate Cox regression analysis, the survival rate was significantly different between the patients with positive Aurora Kinase A and the patients with negative expression (p<0.05) and Aurora Kinase A expression was an independent risk marker of survival(HR=11.263, 95%CI: 2.317–54.748, P=0.003).

Conclusion

Both the Aurora Kinase A and B might involve in the oncogenic, invasive and metastatic process of chondrosarcoma; however, the mechanism is still unclear. The Aurora Kinase A and B could be used as a new prognostic marker and molecular therapeutic target for chondrosarcoma.

Virtual Slide

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9101494267377096.

Aurora kinase A (AURKA) and never in mitosis gene A-related kinase 6 (NEK6) genes are upregulated in erosive esophagitis and esophageal adenocarcinoma

Gastroesophageal reflux disease is a risk factor for esophageal adenocarcinoma yet studies that have investigated the relationship between erosive esophagitis and esophageal adenocarcinoma have usually focused on symptom-related evidence or polymorphisms. There are no epigenetic gene expression studies on this topic. In this study, we aimed to evaluate the relationship between erosive esophagitis and esophageal adenocarcinoma to identify whether there is a genetic predisposition for esophageal adenocarcinoma. The Human Epigenetic Chromatin Modification Enzyme RT(2) Profiler(™) PCR array (PAHS-085A) was used to detect the expression of 84 key genes encoding enzymes. This was carried out prospectively for samples from 60 patients (20 patients as a control group, 20 patients with erosive esophagitis and 20 patients with esophageal adenocarcinoma). AURKA, AURKB, NEK6 were expressed at significantly higher levels in esophageal adenocarcinoma compared to the control group. MBD2 was expressed at significantly lower levels in the esophageal adenocarcinoma group compared to the control group. AURKA, AURKC, HDAC9 and NEK6 were expressed at significantly higher levels in erosive esophagitis compared to the control group. There was no difference in upregulated gene expression between the erosive esophagitis and esophageal adenocarcinoma. MBD2 was significantly downregulated in esophageal adenocarcinoma compared to erosive esophagitis. NEK6 and AURKA were significantly upregulated in esophageal adenocarcinoma and erosive esophagitis compared to the control group. This is a novel study on the genetic predisposition for erosive esophagitis and esophageal adenocarcinoma. AURKA and NEK6 are two promising genetic markers for erosive esophagitis and esophageal adenocarcinoma.