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

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.

Clinical translation for targeting DNA damage repair in non-small cell lung cancer: a review

Despite significant advancements in screening, diagnosis, and treatment of non-small cell lung cancer (NSCLC), it remains the primary cause of cancer-related deaths globally. DNA damage is caused by the exposure to exogenous and endogenous factors and the correct functioning of DNA damage repair (DDR) is essential to maintain of normal cell circulation. The presence of genomic instability, which results from defective DDR, is a critical characteristic of cancer. The changes promote the accumulation of mutations, which are implicated in cancer cells, but these may be exploited for anti-cancer therapies. NSCLC has a distinct genomic profile compared to other tumors, making precision medicine essential for targeting actionable gene mutations. Although various treatment options for NSCLC exist including chemotherapy, targeted therapy, and immunotherapy, drug resistance inevitably arises. The identification of deleterious DDR mutations in 49.6% of NSCLC patients has led to the development of novel target therapies that have the potential to improve patient outcomes. Synthetic lethal treatment using poly (ADP-ribose) polymerase (PARP) inhibitors is a breakthrough in biomarker-driven therapy. Additionally, promising new compounds targeting DDR, such as ATR, CHK1, CHK2, DNA-PK, and WEE1, had demonstrated great potential for tumor selectivity. In this review, we provide an overview of DDR pathways and discuss the clinical translation of DDR inhibitors in NSCLC, including their application as single agents or in combination with chemotherapy, radiotherapy, and immunotherapy.

EZH2 as a prognostic-related biomarker in lung adenocarcinoma correlating with cell cycle and immune infiltrates

BACKGROUNDS

It has been observed that high levels of enhancer of zeste homolog 2 (EZH2) expression are associated with unsatisfactory prognoses and can be found in a wide range of malignancies. However, the effects of EZH2 on Lung Adenocarcinoma (LUAD) remain elusive. Through the integration of bioinformatic analyses, the present paper sought to ascertain the effects of EZH2 in LUAD.

METHODS

The TIMER and UALCAN databases were applied to analyze mRNA and protein expression data for EZH2 in LUAD. The result of immunohistochemistry was obtained from the HPA database, and the survival curve was drawn according to the library provided by the HPA database. The LinkedOmics database was utilized to investigate the co-expressed genes and signal transduction pathways with EZH2. Up- and down-regulated genes from The Linked Omics database were introduced to the CMap database to predict potential drug targets for LUAD using the CMap database. The association between EZH2 and cancer-infiltrating immunocytes was studied through TIMER and TISIDB. In addition, this paper explores the relationship between EZH2 mRNA expression and NSCLC OS using the Kaplan-Meier plotter database to further validate and complement the research. Furthermore, the correlation between EZH2 expression and EGFR genes, KRAS genes, BRAF genes, and smoking from the Cancer Genome Atlas (TCGA) database is analyzed.

RESULTS

In contrast to paracancer specimens, the mRNA and protein levels of EZH2 were higher in LUAD tissues. Significantly, high levels of EZH2 were associated with unsatisfactory prognoses in LUAD patients. Additionally, the coexpressed genes of EZH2 were predominantly associated with numerous cell growth-associated pathways, including the cell cycle, DNA replication, RNA transport, and the p53 signaling pathway, according to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways. The results of TCGA database revealed that the expression of EZH2 was lower in normal tissues than in lung cancer tissues (p < 0.05). Smoking was associated with elevated EZH2 expression (p < 0.001). EZH2 was highly expressed in lung cancers with positive KRAS expression, and the correlation was significant in lung adenocarcinoma (r = 0.3129, p < 0.001). CMap was applied to determine the top 15 positively correlated drugs/molecules and the top 15 negatively correlated drugs/molecules. MK-1775, MK-5108, fenbendazole, albendazole, BAY-K8644, evodiamine, purvalanol-a, mycophenolic-acid, PHA-793887, and cyclopamine are potential drugs for patients with lung adenocarcinoma and high EZH2 expression.

CONCLUSIONS

Highly expressed EZH2 is a predictor of a suboptimal prognosis in LUAD and may serve as a prognostic marker and target gene for LUAD. The underlying cause may be associated with the synergistic effect of KRAS, immune cell infiltration, and metabolic processes.

The involvement of Aurora-A and p53 in oxaliplatin-resistant colon cancer cells

Resistance to chemotherapy is the deadlock in cancer treatment. In this study, we used wild-type LOVO (LOVO^WT ), a human colon cancer cell line, and the oxaliplatin-resistant sub-clone LOVO^OR cells to investigate the molecular mechanisms of the development of drug resistance in colon cancer. Compared with LOVO^WT cells, LOVO^OR cells had a high proliferation capacity and a high percentage on the G2/M phase. The expression and activation of Aurora-A, a critical kinase in G2/M phase, were higher in LOVO^OR cells than in LOVO^WT cells. The results from immunofluorescence indicated an irregular distribution of Aurora-A in LOVO^OR cells. To evaluate the importance of Aurora-A in oxaliplatin-resistant property of LOVO^OR cells, overexpression of Aurora-A in LOVO^WT cells and otherwise knockdown of Aurora-A in LOVO^OR cells were performed and followed by administration of oxaliplatin. The results indicated that Aurora-A might contribute to the resistance of LOVO^OR cells to oxaliplatin treatment by depressing p53 signaling. The specific findings in this study provide a possibility that targeting Aurora-A might be a solution for patients who have failed oxaliplatin treatment.

Unweaving the mitotic spindle: A focus on Aurora kinase inhibitors in lung cancer

Lung cancer is one of the most aggressive malignancies, classified into two major histological subtypes: non-small cell lung cancer (NSCLC), that accounts for about 85% of new diagnosis, and small cell lung cancer (SCLC), the other 15%. In the case of NSCLC, comprehensive genome sequencing has allowed the identification of an increasing number of actionable targets, which have become the cornerstone of treatment in the advanced setting. On the other hand, the concept of oncogene-addiction is lacking in SCLC, and the only innovation of the last 30 years has been the introduction of immune checkpoint inhibitors in extensive stage disease. Dysregulation of cell cycle is a fundamental step in carcinogenesis, and Aurora kinases (AURKs) are a family of serine/threonine kinases that play a crucial role in the correct advance through the steps of the cycle. Hyperexpression of Aurora kinases is a common protumorigenic pathway in many cancer types, including NSCLC and SCLC; in addition, different mechanisms of resistance to anticancer drugs rely on AURK expression. Hence, small molecule inhibitors of AURKs have been developed in recent years and tested in several malignancies, with different results. The aim of this review is to analyze the current evidences of AURK inhibition in lung cancer, starting from preclinical rationale to finish with clinical trials available up to now.

Blocking AURKA with MK-5108 attenuates renal fibrosis in chronic kidney disease

Renal fibrosis, a common feature of chronic kidney disease (CKD), is characterized by excessive deposition of extracellular matrix (ECM) leading to scar formation in the renal parenchyma. Active epithelial-mesenchymal communication (EMC), and the proliferation and activation of fibroblasts are implicated in the causation of renal fibrosis. Aurora-A kinase (AURKA) is a serine/threonine kinase required for the process of mitosis. Dysregulation of AURKA has been demonstrated in the context of various cancers. However, the role of AURKA in CKD-associated fibrosis has not been elucidated. MK-5108, a potent and highly selective AURKA inhibitor, was shown to exhibit anti-cancer activity in recent preclinical and clinical studies. In the present study, we investigated the role of MK-5108 in renal fibrosis employing animal and cell models. In vivo, AURKA was highly expressed in fibrotic kidneys of CKD patients and in mouse kidneys with unilateral ureteral obstruction (UUO). Post treatment with MK-5108 at the 3rd day after UUO remarkably alleviated renal fibrosis, possibly by inhibiting the proliferation and activation of fibroblasts and suppressing the phenotypic transition of renal cells. Moreover, the enhanced inflammatory factors in obstructive kidneys were also repressed. In vitro, MK-5108 treatment inhibited the pro-fibrotic response in renal cells induced by transforming growth factor-β1. Finally, overexpression of AURKA in renal fibroblasts promoted fibrotic response, while silencing AURKA showed anti-fibrotic effect, further confirming the pro-fibrotic role of AURKA. In this study, inhibition of AURKA by MK-5108 markedly attenuated renal fibrosis. MK-5108 is a potential therapeutic agent for treatment of renal fibrosis in CKD.

High-throughput kinase inhibitor screening reveals roles for Aurora and Nuak kinases in neurite initiation and dendritic branching

Kinases are essential regulators of a variety of cellular signaling processes, including neurite formation—a foundational step in neurodevelopment. Aberrant axonal sprouting and failed regeneration of injured axons are associated with conditions like traumatic injury, neurodegenerative disease, and seizures. Investigating the mechanisms underlying neurite formation will allow for identification of potential therapeutics. We used a kinase inhibitor library to screen 493 kinase inhibitors and observed that 45% impacted neuritogenesis in Neuro2a (N-2a) cells. Based on the screening, we further investigated the roles of Aurora kinases A, B, and C and Nuak kinases 1 and 2. The roles of Aurora and Nuak kinases have not been thoroughly studied in the nervous system. Inhibition or overexpression of Aurora and Nuak kinases in primary cortical neurons resulted in various neuromorphological defects, with Aurora A regulating neurite initiation, Aurora B and C regulating neurite initiation and elongation, all Aurora kinases regulating arborization, and all Nuak kinases regulating neurite initiation and elongation and arborization. Our high-throughput screening and analysis of Aurora and Nuak kinases revealed their functions and may contribute to the identification of therapeutics.

Aurora kinase inhibitors: a patent review (2014-2020)

Introduction: Aurora kinases are a family of serine/threonine kinases, and promote mitotic spindle assembly by regulating centrosome duplication and separation. Aurora kinases are overexpressed in a variety of tumor cell lines, thus, the use of Aurora kinase small-molecule inhibitors has become a potential treatment option for cancer.Areas covered: As a continuing review of Aurora kinase inhibitors and their patents published in 2009, 2011 and 2014. Herein, we updated the information for Aurora kinase inhibitors in clinical trials and the patents filed from 2014 to 2020. PubMed, Scopus, SciFinder, and www.clinicaltrials.gov databases were used for searching the clinical information and patents of Aurora kinase inhibitors.Expert opinion: Even though Aurora A or B selective as well as pan inhibitors show preclinical and clinical efficacy, so far, no Aurora kinase inhibitor has been approved for clinical use. Preliminary evidence suggested that highly selective Aurora kinase or multi-target inhibitors as a single agent as well as in combination therapy are still the current main development trend of Aurora kinase inhibitors.

Targeting AURKA in Cancer: molecular mechanisms and opportunities for Cancer therapy

Aurora kinase A (AURKA) belongs to the family of serine/threonine kinases, whose activation is necessary for cell division processes via regulation of mitosis. AURKA shows significantly higher expression in cancer tissues than in normal control tissues for multiple tumor types according to the TCGA database. Activation of AURKA has been demonstrated to play an important role in a wide range of cancers, and numerous AURKA substrates have been identified. AURKA-mediated phosphorylation can regulate the functions of AURKA substrates, some of which are mitosis regulators, tumor suppressors or oncogenes. In addition, enrichment of AURKA-interacting proteins with KEGG pathway and GO analysis have demonstrated that these proteins are involved in classic oncogenic pathways. All of this evidence favors the idea of AURKA as a target for cancer therapy, and some small molecules targeting AURKA have been discovered. These AURKA inhibitors (AKIs) have been tested in preclinical studies, and some of them have been subjected to clinical trials as monotherapies or in combination with classic chemotherapy or other targeted therapies.

Identification of Potential Hub Genes and Therapeutic Drugs in Malignant Pleural Mesothelioma by Integrated Bioinformatics Analysis

INTRODUCTION

Malignant pleural mesothelioma (MPM) is closely linked to asbestos exposure and is an extremely aggressive tumor with poor prognosis.

OBJECTIVE

Our study aimed to elucidate hub genes and potential drugs in MPM by integrated bioinformatics analysis.

METHODS

GSE42977 was download from the Gene Expression Omnibus (GEO) database; the differentially expressed genes (DEGs) with adj.p value <0.05 and |logFC| ≥2 were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed by DAVID database. The STRING database was used to construct a protein-protein interaction network, and modules analysis and hub genes acquisition were performed by Cytoscape. The Gene Expression Profiling Interactive Analysis (GEPIA) database was used to assess the impact of hub genes on the prognosis of MPM patients. The Drug-Gene Interaction database (DGIdb) was used to select the related drugs.

RESULTS

A total of 169 upregulated and 70 downregulated DEGs were identified. These DEGs are enriched in the pathway of extracellular matrix-receptor interaction, focal adhesion, PI3K-Akt signaling pathway, and PPAR signaling pathway. Finally, 10 hub genes (CDC20, CDK1, UBE2C, TOP2A, CCNB2, NUSAP1, KIF20A, AURKA, CEP55, and ASPM) were identified, which are considered to be closely related to the poor prognosis of MPM. In addition, 119 related drugs that may have a therapeutic effect on MPM were filtered out.

CONCLUSION

These discovered genes and small-molecule drugs provide some new ideas for further research on MPM.

Targeting mitosis exit: A brake for cancer cell proliferation

The transition from mitosis to interphase, referred to as mitotic exit, is a critical mitotic process which involves activation and inactivation of multiple mitotic kinases and counteracting protein phosphatases. Loss of mitotic exit checkpoints is a common feature of cancer cells, leading to mitotic dysregulation and confers cancer cells with oncogenic characteristics, such as aberrant proliferation and microtubule-targeting agent (MTA) resistance. Since MTA resistance results from cancer cells prematurely exiting mitosis (mitotic slippage), blocking mitotic exit is believed to be a promising anticancer strategy. Moreover, based on this theory, simultaneous inhibition of mitotic exit and additional cell cycle phases would likely achieve synergistic antitumor effects. In this review, we divide the molecular regulators of mitotic exit into four categories based on their different regulatory functions: 1) the anaphase-promoting complex/cyclosome (APC/C, a ubiquitin ligase), 2) cyclin B, 3) mitotic kinases and phosphatases, 4) kinesins and microtubule-binding proteins. We also review the regulators of mitotic exit and propose prospective anticancer strategies targeting mitotic exit, including their strengths and possible challenges to their use.

Mitosis inhibitors in anticancer therapy: When blocking the exit becomes a solution

Current microtubule-targeting agents (MTAs) remain amongst the most important antimitotic drugs used against a broad range of malignancies. By perturbing spindle assembly, MTAs activate the spindle assembly checkpoint (SAC), which induces mitotic arrest and subsequent apoptosis. However, besides toxic side effects and resistance, mitotic slippage and failure in triggering apoptosis in various cancer cells are limiting factors of MTAs efficacy. Alternative strategies to target mitosis without affecting microtubules have, thus, led to the identification of small molecules, such as those that target spindle Kinesins, Aurora and Polo-like kinases. Unfortunately, these so-called second-generation of antimitotics, encompassing mitotic blockers and mitotic drivers, have failed in clinical trials. Our recent understanding regarding the mechanisms of cell death during a mitotic arrest pointed out apoptosis as the main variable, providing an opportunity to control the cell fates and influence the effectiveness of antimitotics. Here, we provide an overview on the second-generation of antimitotics, and discuss possible strategies that exploit SAC activity, mitotic slippage/exit and apoptosis induction, in order to improve the efficacy of anticancer strategies that target mitosis.

Potential new biomarkers for squamous carcinoma of the uterine cervix

Aim

An in silico pathway analysis was performed in an attempt to identify new biomarkers for cervical carcinoma.

Methods

Three publicly available Affymetrix gene expression data sets (GSE5787, GSE7803, GSE9750) were retrieved, vouching for a total 9 cervical cancer cell lines, 39 normal cervical samples, 7 CIN3 samples and 111 cervical cancer samples. An Agilent data set (GSE7410; 5 normal cervical samples, 35 samples from invasive cervical cancer) was selected as a validation set. Predication analysis of microarrays was performed in the Affymetrix sets to identify cervical cancer biomarkers. We compared the lists of differentially expressed genes between normal and CIN3 samples on the one hand (n=1923) and between CIN3 and invasive cancer samples on the other hand (n=628).

Results

Seven probe sets were identified that were significantly overexpressed (at least 2 fold increase expression level, and false discovery rate <5%) in both CIN3 samples respective to normal samples and in cancer samples respective to CIN3 samples. From these, five probes sets could be validated in the Agilent data set (P<0.001) comparing the normal with the invasive cancer samples, corresponding to the genes DTL, HMGB3, KIF2C, NEK2 and RFC4. These genes were additionally overexpressed in cervical cancer cell lines respective to the cancer samples. The literature on these markers was reviewed.

Conclusion

Novel biomarkers in combination with primary human papilloma virus (HPV) testing may allow complete cervical screening by objective, non-morphological molecular methods, which may be particularly important in developing countries.

The Aurora kinase A inhibitor TC-A2317 disrupts mitotic progression and inhibits cancer cell proliferation

Mitotic progression is crucial for the maintenance of chromosomal stability. A proper progression is ensured by the activities of multiple kinases. One of these enzymes, the serine/threonine kinase Aurora A, is required for proper mitosis through the regulation of centrosome and spindle assembly. In this study, we functionally characterized a newly developed Aurora kinase A inhibitor, TC-A2317. In human lung cancer cells, TC-A2317 slowed proliferation by causing aberrant formation of centrosome and microtubule spindles and prolonging the duration of mitosis. Abnormal mitotic progression led to accumulation of cells containing micronuclei or multinuclei. Furthermore, TC-A2317–treated cells underwent apoptosis, autophagy or senescence depending on cell type. In addition, TC-A2317 inactivated the spindle assembly checkpoint triggered by paclitaxel, thereby exacerbating mitotic catastrophe. Consistent with this, the expression level of Aurora A in tumors was inversely correlated with survival in lung cancer patients. Collectively, these data suggest that inhibition of Aurora kinase A using TC-A2317 is a promising target for anti-cancer therapeutics.

Inhibition of Aurora Kinase A Synergistically Enhances Cytotoxicity in Ovarian Clear Cell Carcinoma Cell Lines Induced by Cisplatin: A Potential Treatment Strategy

OBJECTIVE

This study aims to clarify the incidence of Aurora kinase A (Aurora-A) protein expression and its correlation with clinical parameters in ovarian clear cell carcinoma (OCCC) tumor tissues. In addition, we assessed the efficacy of ENMD-2076, a novel selective Aurora-A inhibitor, in combination with chemotherapeutic agents for the treatment of OCCC.

METHODS/MATERIALS

Aurora-A protein expression was determined by immunohistochemical staining of OCCC specimens from 56 patients to evaluate its correlation with clinical outcomes in OCCC. In the in vitro study, 6 OCCC cell lines were exposed to ENMD-2076 in combination with cisplatin, SN38, doxorubicin, or paclitaxel, and cell proliferation, cell cycle distribution, and apoptosis were assessed.

RESULTS

The 5-year survival rates of International Federation of Gynecology and Obstetrics stages IC3 to IV patients with intermediate or strong Aurora-A expression were significantly lower than those of patients with negative or weak Aurora-A expression. Increased Aurora-A expression was associated with significantly worse overall survival of International Federation of Gynecology and Obstetrics stages IC3 to IV patients (21% vs 77%). Multivariate analysis revealed that Aurora-A expression was an independent prognostic factor for stages IC3 to IV OCCC patients. Furthermore, synergistic effects were observed with ENMD-2076 in combination with cisplatin or SN-38 in 4 of the 6 tested cell lines. ENMD-2076 dramatically enhanced apoptosis and cell cycle arrest at the G2/M phase induced by cisplatin.

CONCLUSIONS

Aurora-A is a promising biomarker that is predictive of patient outcomes and a potential target for OCCC. The results suggested that chemotherapy, including ENMD-2076 in combination with cisplatin, is a potential treatment modality for patients with OCCC.

Preclinical evaluation of the Aurora kinase inhibitors AMG 900, AZD1152-HQPA, and MK-5108 on SW-872 and 93T449 human liposarcoma cells

Liposarcoma is a malignant soft tissue tumor that originates from adipose tissue and is one of the most frequently diagnosed soft tissue sarcomas in humans. There is great interest in identifying novel chemotherapeutic options for treating liposarcoma based upon molecular alterations in the cancer cells. The Aurora kinases have been identified as promising chemotherapeutic targets based on their altered expression in many human cancers and cellular roles in mitosis and cytokinesis. In this study, we investigated the effects of an Aurora kinase A inhibitor (MK-5108), an Aurora kinase B inhibitor (AZD1152-HQPA), and a pan-Aurora kinase inhibitor (AMG 900) on undifferentiated SW-872 and well-differentiated 93T449 human liposarcoma cells. Treatment of the SW-872 and 93T449 cells with MK-5108 (0-1000 nM), AZD1152-HQPA (0-1000 nM), and AMG 900 (0-1000 nM) for 72 h resulted in a dose-dependent decrease in the total viable cell number. Based upon the EC₅₀ values, the potency of the three Aurora kinase inhibitors in the SW-872 cells was as follows: AMG 900 (EC₅₀ = 3.7 nM) > AZD1152-HQPA (EC₅₀ = 43.4 nM) > MK-5108 (EC₅₀ = 309.0 nM), while the potency in the 93T449 cells was as follows: AMG 900 (EC₅₀ = 6.5 nM) > AZD1152-HQPA (EC₅₀ = 74.5 nM) > MK-5108 (EC₅₀ = 283.6 nM). The percentage of polyploidy after 72 h of drug treatment (0-1000 nM) was determined by propidium iodide staining and flow cytometric analysis. AMG 900 caused a significant increase in polyploidy starting at 25 nM in the SW-872 and 93T449 cells, and AZD1152-HQPA caused a significant increase starting at 100 nM in the SW-872 cells and 250 nM in the 93T449 cells. The Aurora kinase A inhibitor MK-5108 did not significantly increase the percentage of polyploid cells at any of the doses tested in either cell line. The expression of Aurora kinase A and B was evaluated in the SW-872 cells versus differentiated adipocytes and human mesenchymal stem cells by real-time RT-PCR and Western blot analysis. Aurora kinase A and B mRNA expression was significantly increased in the SW-872 cells versus the differentiated adipocytes and human mesenchymal stem cells. Western blot analysis revealed a ~ 48 kDa immunoreactive band for Aurora kinase A that was not present in the differentiated adipocytes or the human mesenchymal stem cells. A ~ 39 kDa immunoreactive band for Aurora kinase B was detected in the SW-872 cells, differentiated adipocytes, and human mesenchymal stem cells. A smaller immunoreactive band for Aurora kinase B was detected in the SW-872 cells but not in the differentiated adipocytes and human mesenchymal stem cells, and this may reflect the expression of a truncated splice variant of Aurora kinase B that has been associated with poor patient prognosis. The 93T449 cells demonstrated decreased expression of Aurora kinase A and B mRNA and protein compared to the SW-872 cells, and also expressed the truncated form of Aurora kinase B. The results of these in vitro studies indicate that Aurora kinase inhibitors should be further investigated as possible chemotherapeutic agents for human liposarcoma.

AURKA, DLGAP5, TPX2, KIF11 and CKAP5: Five specific mitosis-associated genes correlate with poor prognosis for non-small cell lung cancer patients

The growth of a tumor depends to a certain extent on an increase in mitotic events. Key steps during mitosis are the regulated assembly of the spindle apparatus and the separation of the sister chromatids. The microtubule-associated protein Aurora kinase A phosphorylates DLGAP5 in order to correctly segregate the chromatids. Its activity and recruitment to the spindle apparatus is regulated by TPX2. KIF11 and CKAP5 control the correct arrangement of the microtubules and prevent their degradation. In the present study, we investigated the role of these five molecules in non-small cell lung cancer (NSCLC). We analyzed the expression of the five genes in a large cohort of NSCLC patients (n=362) by quantitative real-time PCR. Each of the genes was highly overexpressed in the tumor tissues compared to corresponding normal lung tissue. The correlation of the expression of the individual genes depended on the histology. An increased expression of AURKA, DLGAP5, TPX2, KIF11 and CKAP5 was associated with poor overall survival (P=0.001–0.065). AURKA was a significant prognostic marker using multivariate analyses (P=0.006). Immunofluorescence studies demonstrated that the five mitosis-associated proteins co-localized with the spindle apparatus during cell division. Taken together, our data demonstrate that the expression of the mitosis-associated genes AURKA, DLGAP5, TPX2, KIF11 and CKAP5 is associated with the prognosis of NSCLC patients.

The Aurora kinase inhibitors in cancer research and therapy

Compounds that affect enzymatic function of kinases are valuable for the understanding of the complex biochemical processes in cells. Aurora kinases (AURKs) play a key role in the control of the mitosis. These kinases are frequently deregulated in different human cancers: overexpression, amplifications, translocations and deletions were reported in many cancer cell lines as well as patient tissues. These findings steered a rigorous hunt for small-molecule AURK inhibitors not only for research purposes as well as for therapeutic uses. In this review, we describe a number of AURK inhibitors and their use in cancer research and/or therapy. We hope to assist researchers and clinicians in deciding which inhibitor is most appropriate for their specific purpose. The review will also provide a broad overview of the clinical studies performed with some of these inhibitors (if such studies have been performed).

Knockdown of Aurora-B inhibits the growth of non-small cell lung cancer A549 cells

Elevated expression of Aurora-B affects cell apoptosis and proliferation in a variety of solid tumors. However, the role of Aurora-B has been poorly evaluated in non-small cell lung cancer (NSCLC). In the present study, it was found that Aurora-B was overexpressed in tissue specimens obtained from 174 patients with lung cancer. It was also demonstrated that knockdown of Aurora-B induces apoptosis and inhibits the growth of lung cancer A549 cells in vitro and in vivo. Furthermore, it was found that silencing Aurora-B decreased the activity of the phosphoinositide 3-kinase (PI3K)/AKT pathway. Therefore, it was concluded that knockdown of Aurora-B induces apoptosis and inhibits growth in NSCLC A549 cells, in addition to inhibiting the activity of the PI3K/AKT signaling pathway. Targeting Aurora-B may provide a novel target for lung cancer therapy.

Safety and activity of alisertib, an investigational aurora kinase A inhibitor, in patients with breast cancer, small-cell lung cancer, non-small-cell lung cancer, head and neck squamous-cell carcinoma, and gastro-oesophageal adenocarcinoma: a five-arm phase 2 study

BACKGROUND

Alisertib is an investigational, oral, selective inhibitor of aurora kinase A. We aimed to investigate the safety and activity of single-agent alisertib in patients with predefined types of advanced solid tumours.

METHODS

We did a multicentre phase 1/2 study at 40 centres in four countries (Czech Republic, France, Poland, and the USA). Here, we report results from phase 2; enrolment for the study began on Feb 16, 2010, and ended on May 3, 2013. Adult patients were eligible for the study if they had either breast cancer, small-cell lung cancer, non-small-cell lung cancer, head and neck squamous-cell carcinoma, or gastro-oesophageal adenocarcinoma that had relapsed or was refractory to chemotherapy. Patients had to have undergone two or fewer previous cytotoxic regimens (four or fewer for breast cancer patients), not including adjuvant or neoadjuvant treatments. Enrolment followed a two-stage design: to proceed to the second stage, two or more objective responses were needed in the first 20 response-assessable patients in each of the five tumour cohorts. Alisertib was administered orally in 21-day cycles at the recommended phase 2 dose of 50 mg twice daily for 7 days followed by a break of 14 days. The protocol-specified primary endpoint was the proportion of patients with an objective response, assessed by Response Evaluation Criteria In Solid Tumors version 1.1 in the response-assessable population (ie, patients with measurable disease who received at least one dose of alisertib and had undergone at least one post-baseline tumour assessment). This completed trial is registered with ClinicalTrials.gov, NCT01045421.

FINDINGS

By May 31, 2013, 249 patients had been treated, 53 with breast cancer, 60 with small-cell lung cancer, 26 with non-small-cell lung cancer, 55 with head and neck squamous-cell carcinoma, and 55 with gastro-oesophageal adenocarcinoma. Among response-assessable patients, an objective response was noted in nine (18%, 95% CI 9-32) of 49 women with breast cancer, ten (21%, 10-35) of 48 participants with small-cell lung cancer, one (4%, 0-22) of 23 patients with non-small-cell lung cancer, four (9%, 2-21) of 45 people with head and neck squamous-cell carcinoma, and four (9%, 2-20) of 47 individuals with gastro-oesophageal adenocarcinoma; all were partial responses. Adverse events were similar across tumour types. The most frequent drug-related grade 3-4 adverse events included neutropenia (n=107 [43%]), leukopenia (53 [21%]), and anaemia (26 [10%]). Serious drug-related adverse events were reported in 108 (43%) patients.

INTERPRETATION

These data support further clinical assessment of alisertib in patients with solid tumours, particularly those with breast cancer and small-cell lung cancer.

FUNDING

Millennium Pharmaceuticals, Inc, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited.