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

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.

Emerging roles of Aurora-A kinase in cancer therapy resistance

Aurora kinase A (Aurora-A), a serine/threonine kinase, plays a pivotal role in various cellular processes, including mitotic entry, centrosome maturation and spindle formation. Overexpression or gene-amplification/mutation of Aurora-A kinase occurs in different types of cancer, including lung cancer, colorectal cancer, and breast cancer. Alteration of Aurora-A impacts multiple cancer hallmarks, especially, immortalization, energy metabolism, immune escape and cell death resistance which are involved in cancer progression and resistance. This review highlights the most recent advances in the oncogenic roles and related multiple cancer hallmarks of Aurora-A kinase-driving cancer therapy resistance, including chemoresistance (taxanes, cisplatin, cyclophosphamide), targeted therapy resistance (osimertinib, imatinib, sorafenib, etc.), endocrine therapy resistance (tamoxifen, fulvestrant) and radioresistance. Specifically, the mechanisms of Aurora-A kinase promote acquired resistance through modulating DNA damage repair, feedback activation bypass pathways, resistance to apoptosis, necroptosis and autophagy, metastasis, and stemness. Noticeably, our review also summarizes the promising synthetic lethality strategy for Aurora-A inhibitors in RB1, ARID1A and MYC gene mutation tumors, and potential synergistic strategy for mTOR, PAK1, MDM2, MEK inhibitors or PD-L1 antibodies combined with targeting Aurora-A kinase. In addition, we discuss the design and development of the novel class of Aurora-A inhibitors in precision medicine for cancer treatment.

Targeted protein degradation: A promise for undruggable proteins

Protein homeostasis, or "proteostasis," is indispensable for a balanced, healthy environment within the cell. However, when natural proteostasis mechanisms are overwhelmed from excessive loads of dysregulated proteins, their accumulation can lead to disease initiation and progression. Recently, the induced degradation of such disease-causing proteins by heterobifunctional molecules, i.e., PROteolysis TArgeting Chimeras (PROTACs), is emerging as a potential therapeutic modality. In the 2 decades since the PROTAC concept was proposed, several additional Targeted Protein Degradation (TPD) strategies have also been explored to target previously undruggable proteins, such as transcription factors. In this review, we discuss the progress and evolution of the TPD field, the breadth of the proteins targeted by PROTACs and the biological effects of their degradation.

The Relevance of Aurora Kinase Inhibition in Hematological Malignancies

Aurora kinases are a family of serine/threonine protein kinases that play a central role in eukaryotic cell division. Overexpression of aurora kinases in cancer and their role as major regulators of the cell cycle quickly inspired the idea that their inhibition might be a potential pathway when treating oncologic patients. Over the past couple of decades, the search for designing and testing of molecules capable of inhibiting aurora activities fueled many pre-clinical and clinical studies. In this study, data from the past 10 years of in vitro and in vivo investigations, as well as clinical trials, utilizing aurora kinase inhibitors as therapeutics for hematological malignancies were compiled and discussed, aiming to highlight potential uses of these inhibitors as a novel monotherapy model or alongside conventional chemotherapies. While there is still much to be elucidated, it is clear that these kinases play a key role in oncogenesis, and their manageable toxicity and potentially synergistic effects still render them a focus of interest for future investigations in combinatorial clinical trials.

Curcumin Rescues Doxorubicin Responsiveness via Regulating Aurora a Signaling Network in Breast Cancer Cells

BACKGROUND

Insensitivity towards anthracycline drugs like doxorubicin poses a significant challenge in the treatment of breast cancer. Among several factors, Aurora A (a mitotic serine threonine kinase) plays crucial roles in acquiring non-responsiveness towards doxorubicin. However, the mechanisms underlying need to be elucidated. The present study was therefore designed to evaluate the underlying mechanisms of Aurora A mediated doxorubicin insensitivity in MCF-7Dox/R, an isolated resistant-subline of MCF-7 (breast adenocarcinoma cell line). Effect of curcumin, a natural phytochemical in restoring doxorubicin sensitivity by targeting Aurora A was assessed furthermore.

METHODS

A doxorubicin resistant subline (MCF-7Dox/R) was isolated from the parental MCF-7 cells by treating the cell with gradual step-wise increasing concentration of the drug. Expressions of Aurora A and its target proteins (Akt, IκBα and NFκB) were assessed in both parental and MCF-7Dox/R cells. Both the cell lines were pretreated with curcumin prior to doxorubicin treatment. Cellular proliferation rate was measured using BrdU (5-bromo-2'-deoxyuridine) assay kit. Intracellular doxorubicin accumulation was estimated spectrofluorimetrically. Cellular uptake of curcumin (spectrophotometric and spectrofluorimetric method) and its nuclear localization was confirmed by confocal microscopic study. Protein expressions were determined by western blot analysis. Localization of Aurora A was ascertained by immunofluorescence assay. To explore the possible outcome of impact of curcumin on Aurora A, cell-cycle distribution and apoptosis were performed subsequently.

RESULTS

Higher expressions of Aurora A in MCF-7Dox/R cells led to phosphorylation of Akt as well as IκBα. Phosphorylated IκBα preceded release of NFκB. Phospho-Akt, NFκB consequentially decreased doxorubicin accumulation by enhancing the expressions of ABCG2 and Pgp1 respectively. Curcumin by regulating Aurora A and its target molecules sensitized resistant subline towards doxorubicin mediated G2/M-arrest and apoptosis.

CONCLUSION

Molecular targeting of Aurora A by curcumin restores chemosensitivity by increasing the efficacy of doxorubicin in breast cancer.<br />.

The role of Aurora-A in human cancers and future therapeutics

Aurora-A is a mitotic serine/threonine-protein kinase and an oncogene. In normal cells, Aurora-A appears from G2 phase and localizes at the centrosome, where it participates in centrosome replication, isolation and maturation. Aurora-A also maintains Golgi apparatus structure and spindle assembly. Aurora-A undergoes ubiquitination-mediated degradation after the cell division phase. Aurora-A is abnormally expressed in tumor cells and promotes cell proliferation by regulating mitotic substrates, such as PP1, PLK1, TPX2, and LAST2, and affects other molecules through a non-mitotic pathway to promote cell invasion and metastasis. Some molecules in tumor cells also indirectly act on Aurora-A to regulate tumor cells. Aurora-A also mediates resistance to chemotherapy and radiotherapy and is involved in tumor immunotherapy. Clinical trials of Aurora-A molecular inhibitors are currently underway, and clinical transformation is just around the corner.

Association of the Epithelial-Mesenchymal Transition (EMT) with Cisplatin Resistance

Therapy resistance is a characteristic of cancer cells that significantly reduces the effectiveness of drugs. Despite the popularity of cisplatin (CP) as a chemotherapeutic agent, which is widely used in the treatment of various types of cancer, resistance of cancer cells to CP chemotherapy has been extensively observed. Among various reported mechanism(s), the epithelial-mesenchymal transition (EMT) process can significantly contribute to chemoresistance by converting the motionless epithelial cells into mobile mesenchymal cells and altering cell-cell adhesion as well as the cellular extracellular matrix, leading to invasion of tumor cells. By analyzing the impact of the different molecular pathways such as microRNAs, long non-coding RNAs, nuclear factor-κB (NF-ĸB), phosphoinositide 3-kinase-related protein kinase (PI3K)/Akt, mammalian target rapamycin (mTOR), and Wnt, which play an important role in resistance exhibited to CP therapy, we first give an introduction about the EMT mechanism and its role in drug resistance. We then focus specifically on the molecular pathways involved in drug resistance and the pharmacological strategies that can be used to mitigate this resistance. Overall, we highlight the various targeted signaling pathways that could be considered in future studies to pave the way for the inhibition of EMT-mediated resistance displayed by tumor cells in response to CP exposure.

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

OBJECTIVES

Overexpression of aurora kinase A (AURKA) confers a poor prognosis in patients with urothelial carcinoma of the bladder. The prognostic value of high aurora kinase B (AURKB) expression in local bladder cancer is not well defined, and whether the prognostic value of either AURKA or AURKB is affected by the use of chemotherapy is unknown. We sought to characterize the impact of high AURKA and AURKB expression on clinical outcome in patients with muscle-invasive bladder cancer (MIBC) who received neoadjuvant chemotherapy (NAC).

MATERIALS AND METHODS

Immunohistochemistry for AURKA and AURKB was performed on pretreatment diagnostic transurethral resection of bladder tumor (TURBT) and matched cystectomy specimens in 50 subjects with MIBC who received NAC. Receiver operator characteristic curves (ROC) were calculated to assess the impact of AURKA and AURKB expression on pathologic response rate. Kaplan-Meier techniques and Cox proportional hazards models were used to assess the association with relapse-free survival (RFS) and overall survival (OS).

RESULTS

Twenty-two of 50 [44%] patients had residual muscle-invasive (ypT2-4) urothelial carcinoma after NAC. Neither baseline tumor expression of AURKA (ROC = 0.57, P = 0.46) nor AURKB (ROC = 0.56, P = 0.87) predicted for ypT2-4 status. However, baseline expression of AURKA above the 75th percentile for this cohort was associated with an inferior RFS, (HR = 3.88, P = 0.008) and OS, (HR = 6.10, P < 0.001). Similar trends for worse survival outcomes were also observed for high AURKB levels (RFS, [HR = 2.2, P = 0.13] and OS, (HR = 2.25, P = 0.09).

CONCLUSIONS

High baseline tumor AURKA and AURKB expression identified MIBC patients with inferior RFS and OS despite the use of NAC and may identify patients who should be prioritized for clinical trial enrollment rather than standard cisplatin-based chemotherapy.

Discovery of Inhibitors of Aurora/PLK Targets as Anticancer Agents

Aurora and polo-like kinases control the G2/M phase in cell mitosis, which are both considered as crucial targets for cancer cell proliferations. Here, naphthalene-based Aurora/PLK coinhibitors as leading compounds were designed through in silico approach, and a total of 36 derivatives were synthesized. One candidate (AAPK-25) was selected under in vitro cell based high throughput screening with an IC50 value = 0.4 μM to human colon cancer cell HCT-116. A kinome scan assay showed that AAPK-25 was remarkably selective to both Aurora and PLK families. The relevant genome pathways were also depicted by microarray based gene expression analysis. Furthermore, validated from a set of in vitro and in vivo studies, AAPK-25 significantly inhibited the development of the colon cancer growth and prolonged the median survival time at the end of the administration (p < 0.05). To sum up, AAPK-25 has a great potential to be developed for a chemotherapeutic agent in clinical use.

Capsaicinoids enhance chemosensitivity to chemotherapeutic drugs

Cytotoxic chemotherapy is the mainstay of cancer treatment. Conventional chemotherapeutic agents do not distinguish between normal and neoplastic cells. This leads to severe toxic side effects, which may necessitate the discontinuation of treatment in some patients. Recent research has identified key molecular events in the initiation and progression of cancer, promoting the design of targeted therapies to selectively kill tumor cells while sparing normal cells. Although, the side effects of such drugs are typically milder than conventional chemotherapies, some off-target effects still occur. Another serious challenge with all chemotherapies is the acquisition of chemoresistance upon prolonged exposure to the drug. Therefore, identifying supplementary agents that sensitize tumor cells to chemotherapy-induced apoptosis and help minimize drug resistance would be valuable for improving patient tolerance and response to chemotherapy. The use of effective supplementary agents provides a twofold advantage in combination with standard chemotherapy. First, by augmenting the activity of the chemotherapeutic drug it can lower the dose needed to kill tumor cells and decrease the incidence and severity of treatment-limiting side effects. Second, adjuvant therapies that lower the effective dose of chemotherapy may delay/prevent the development of chemoresistance in tumors. Capsaicinoids, a major class of phytochemical compounds isolated from chili peppers, have been shown to improve the efficacy of several anti-cancer drugs in cell culture and animal models. The present chapter summarizes the current knowledge about the chemosensitizing activity of capsaicinoids with conventional and targeted chemotherapeutic drugs, highlighting the potential use of capsaicinoids in novel combination therapies to improve the therapeutic indices of conventional and targeted chemotherapeutic drugs in human cancers.

Aurora-A Induces Chemoresistance Through Activation of the AKT/mTOR Pathway in Endometrial Cancer

Endometrial cancer (EC) is the most common gynecological tumor all over the world, and advanced/metastatic EC remains a malignancy with poor survival outcome due to highly resistant to conventional chemotherapeutic treatment. Here, we report that Aurora-A, a serine-threonine kinase, plays a vital role in chemoresistance of EC. Aurora-A is overexpressed in EC tissues, compared with normal endometrium and Aurora-A expression is associated with decreased overall survival. Overexpression of Aurora-A in EC cell lines (Ishikawa and HEC-1B cells) promotes cell proliferation and induced paclitaxel- and cisplatin-resistance. Furthermore, Aurora-A activating AKT-mTOR pathway further induces chemoresistance in vitro, consistent with a positive correlation between Aurora-A and phosphorylated AKT/4E-BP1 expression in EC tissues. In summary, our study provides the strong evidence that Aurora-A controls the sensitivity of EC cell lines to chemotherapy via AKT/mTOR pathway, indicating that pharmacologic intervention of Aurora-A and AKT/mTOR in combination with chemotherapy may be considered for the targeted therapy against EC with overexpression of Aurora-A.

Zinc finger AN1-type containing 4 is a novel marker for predicting metastasis and poor prognosis in oral squamous cell carcinoma

AIMS

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth most common cancer worldwide and has a high potential for locoregional invasion and nodal metastasis. Therefore, discovery of a useful molecular biomarker capable of predicting tumour progression and metastasis of OSCC is crucial. We have previously reported zinc finger AN1-type containing 4 (ZFAND4) as one of the most upregulated genes in recurrent OSCC using a cDNA microarray analysis. Although ZFAND4 has been shown to promote cell proliferation of gastric cancer, its expression and clinicopathological roles in OSCC remain unclear.

METHODS

In this study, we examined ZFAND4 expression by immunohistochemistry in 214 cases of OSCC.

RESULTS

High cytoplasmic expression of ZFAND4 was observed in 45 out of 214 (21%) patients with OSCC. Expression levels of ZFAND4 were strongly associated with metastasis to the lymph nodes (p=0.0429) and distant organs (p=0.0068). Cases with high expression of ZFAND4 had a significantly unfavourable prognosis compared with patients with low expression of ZFAND4 (p<0.0001). Furthermore, ZFAND4 overexpression was an independent poor prognostic factor for OSCC as determined by multivariate analysis using the Cox proportional hazards model (p<0.0001).

CONCLUSIONS

These results suggest that ZFAND4 is a useful marker for predicting metastasis and poor prognosis in patients with OSCC.