Aurora B kinase expression in laryngeal squamous cell carcinoma and its prognostic implications

Is the AURKB Gene Involved in Aml Cell Proliferation Since It is Targeted by miR-34a-5p and let-7b-5p?

ABSTRACT Objective: The production of normal blood cells in the bone marrow is interrupted in AML, which is characterized by the proliferation and accumulation of leukemic blasts. Therefore, patients experience anemia and thrombocytopenia. When gene expression of Aurora kinases, which is reported to be highly expressed in AML, decreases, it may be possible to alleviate the clinical findings in AML. In this study, it was aimed to examine the relationship of AURKB with important miRNAs that have the potential to regulate gene expression. Method: HL60 and NB4 cells were transfected with important tumor suppressor miRNAs miR-34a-5p and let-7b-5p mimics. Then, its effects on proliferation were examined with WST-8 technique and its effects on AURKB gene expression were examined with qRT-PCR. Results: It was determined that these miRNAs negatively regulated proliferation in both AML cell lines and downregulated the expression level of the Aurora kinase B (AURKB) gene in the miRNA transfected group compared to the control group. Conclusion: In conclusion, it was determined that miR-34a-5p and let-7b-5p could regulate AURKB expression in AML cells. Therefore, it was thought that these miRNAs may have an important potential as a therapeutic biomarker in preventing excessive cell division and poor prognosis in AML.

Aurora B kinase: a potential drug target for cancer therapy

BACKGROUND

Ensuring genetic integrity is essential during the cell cycle to avoid aneuploidy, one of the underlying causes of malignancies. Aurora kinases are serine/threonine kinase that play a vital role in maintaining the genomic integrity of the cells. There are three forms of aurora kinases in the mammalian cells, which are highly conserved and act together with several other proteins to control chromosome alignment and its equal distribution to daughter cells in mitosis and meiosis.

METHODS

We provide here a detailed analysis of Aurora B kinase (ABK) in terms of its expression, structure, function, disease association and potential therapeutic implications.

RESULTS

ABK plays an instrumental in mitotic entry, chromosome condensation, spindle assembly, cytokinesis, and abscission. Small-molecule inhibitors of ABK are designed and synthesized to control cancer progression. A detailed understanding of ABK pathophysiology in different cancers is of great significance in designing and developing effective therapeutic strategies.

CONCLUSION

In this review, we have discussed the physiological significance of ABK followed by its role in cancer progression. We further highlighted available small-molecule inhibitors to control the tumor proliferation and their mechanistic insights.

Expression of DNA-dependent protein kinase catalytic subunit in laryngeal squamous cell carcinoma and its importance

The aim of the present study was to explore the expression and distribution of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in tumor tissues and adjacent normal mucosa tissues of patients with laryngeal squamous cell carcinoma (LSCC), and further analyze the association between the expression and the clinicopathological parameters of patients with LSCC. Clinical data of tumor tissues and corresponding adjacent normal mucosa tissues of pathologically diagnosed LSCC in 96 cases were collected in the present study. Of these specimens, the mRNA and protein expression levels of DNA-PKcs in LSCC tissues and the adjacent normal mucosa tissues were analyzed via reverse transcription-quantitative polymerase chain reaction and western blot analysis. Immunohistochemistry was used to detect expression and distribution of DNA-PKcs protein in LSCC tissues and corresponding adjacent normal mucosa tissues. The association between DNA-PKcs expression and the specific clinicopathologic features was evaluated by the χ² test. Kaplan-Meier and Cox proportional hazards regression models were used to analyze the data. It was revealed that the expression of DNA-PKcs mRNA and protein was significantly higher in LSCC tissues than the adjacent normal mucosa tissues (P<0.05). DNA-PKcs was expressed predominantly in the nucleus. DNA-PKcs expression showed significant correlation with the differentiation degree of LSCC (P<0.05), and changes of DNA-PKcs expression gradually increased with the decrease of the differentiation degree. However, DNA-PKcs expression was not significantly associated with sex, age, lymph node metastasis or TMN stage (P>0.05). Patients with LSCC exhibited higher DNA-PKcs expression had markedly shorter survival than those with lower DNA-PKcs expression. In conclusion, the present results suggested that the expression levels of DNA-PKcs were significantly increased in LSCC tumor tissues than in adjacent normal mucosa. DNA-PKcs expression was correlated with differentiation of LSCC, and may become a novel prognostic marker for patients with LSCC.

Predictive value of angiogenesis-related gene profiling in patients with HER2-negative metastatic breast cancer treated with bevacizumab and weekly paclitaxel

Bevacizumab plus weekly paclitaxel improves progression-free survival (PFS) in HER2-negative metastatic breast cancer (mBC), but its use has been questioned due to the absence of a predictive biomarker, lack of benefit in overall survival (OS) and increased toxicity. We examined the baseline tumor angiogenic-related gene expression of 60 patients with mBC with the aim of finding a signature that predicts benefit from this drug.

Multivariate analysis by Lasso-penalized Cox regression generated two predictive models: one, named G-model, including 11 genes, and the other one, named GC-model, including 13 genes plus 5 clinical covariates. Both models identified patients with improved PFS (HR (Hazard Ratio) 2.57 and 4.04, respectively) and OS (HR 3.29 and 3.43, respectively). The G-model distinguished low and high risk patients in the first 6 months, whereas the GC-model maintained significance over time.

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.

Aurora-A promotes chemoresistance in hepatocelluar carcinoma by targeting NF-kappaB/microRNA-21/PTEN signaling pathway

Hepatocellular carcinoma (HCC) is highly resistant to chemotherapy. Previously, we have shown that Aurora-A mRNA is upregulated in HCC cells or tissues and silencing of Aurora-A using small interfering RNA (siRNA) decreases growth and enhances apoptosis in HCC cells. However, the clinical significance of Aurora-A protein expression in HCC and association between Aurora-A expression and HCC chemoresistance is unclear. Here, we showed that Aurora-A protein is upregulated in HCC tissues and significantly correlated with recurrence-free and overall survival of patients and multivariate analysis indicated that immunostaining of Aurora-A will be an independent prognostic factor for patients. Silencing of Aurora-A significantly increased the chemosensitivity of HCC cells both in vitro and in vivo, while overexpression of Aurora-A induced the opposite effects. Furthermore, overexpression of Aurora-A reduces chemotherapy-induced apoptosis by promoting microRNA-21 expression, which negatively regulates PTEN and then inhibits caspase-3-mediated apoptosis induction. Mechanically, we demonstrated that Aurora-A promotes expression of nuclear Ikappaβ-alpha (Iκβα) protein and enhances NF-kappa B (NF-κB) activity, thus promotes the transcription of miR-21. This study first reported the involvement of Aurora-A/NF-κB/miR-21/PTEN/Akt signaling axis in chemoresistance of HCC cells, suggesting that targeting this signaling pathway would be helpful as a therapeutic strategy for the reversal of chemoresistance in HCC.

High proliferation index, as determined by immunohistochemical expression of Aurora kinase B and geminin, indicates poor prognosis in neuroblastomas

Expression profile analysis of cell cycle biomarkers provides a powerful index of the proliferative state of tumors, which is linked to disease aggressiveness. We investigated the impact of the biomarkers of S-G2-M phases of cell cycle, Aurora kinase B (AURKB) and geminin (GMNN), on disease progression in neuroblastomas. The expression of AURKB and GMNN was studied by immunostaining 84 neuroblastomas. A proliferation index (PI) was obtained on scanned immunostained slides using image analysis software. The median PI was 8.5 % for AURKB- and 16.8 % for GMNN-stained slides with a high correlation between the two (r s = 0.72, P < 0.001). The PI for both markers was significantly higher in neuroblastomas from patients with unfavorable clinical (high-risk group, advanced stage, age ≥18 months at presentation, primary abdominal compared to extra-abdominal sites), biological (MYCN amplification, 1p deletion, 17q gain), and pathological (undifferentiated or poorly differentiated status, high mitosis-karyorrhexis index, [MKI], unfavorable histology) factors. Using Cox regression models, a higher-than-median AURKB and GMNN PI was associated with a significantly shorter overall survival (OS) and event-free survival (EFS) in univariable analysis. In multivariable analysis, a high AURKB PI was associated with significantly shorter OS and EFS, independent of MYCN amplification, and significantly shorter EFS, independent of MKI. High GMNN PI was also associated with significantly shorter OS and EFS after adjusting for MYCN amplification but failed to reach statistical significance after adjusting for MKI. Our study shows that in neuroblastomas, AURKB- or GMNN-based PI provides valuable prognostic information and high PI indicates aggressive disease.

Small molecule inhibitors in acute myeloid leukemia: from the bench to the clinic

Many patients with acute myeloid leukemia will eventually develop refractory or relapsed disease. In the absence of standard therapy for this population, there is currently an urgent unmet need for novel therapeutic agents. Targeted therapy with small molecule inhibitors represents a new therapeutic intervention that has been successful for the treatment of multiple tumors (e.g., gastrointestinal stromal tumors, chronic myelogenous leukemia). Hence, there has been great interest in generating selective small molecule inhibitors targeting critical pathways of proliferation and survival in acute myeloid leukemia. This review highlights a selective group of intriguing therapeutic agents and their presumed targets in both preclinical models and in early human clinical trials.

Dickkopf-1 is a novel prognostic biomarker for laryngeal squamous cell carcinoma

CONCLUSIONS

Dickkopf-1 (DKK1) is a novel prognostic biomarker for laryngeal squamous cell carcinoma (LSCC). DKK1 may be a promising strategy for the future treatment of LSCC metastasis and recurrence.

OBJECTIVES

DKK1 is reportedly involved in the metastasis and invasion of several tumor types. This study aimed to investigate the prognostic value of DKK1 in LSCC.

METHODS

DKK1 expression was measured in Hep-2 cell lines, as well as in tumor and peritumoral tissues, using quantitative real-time PCR and western blot analyses. The role of DKK1 in LSCC was investigated by depleting DKK1 using small interfering RNAs. Tissue microarrays of 102 LSCC patient samples were employed to immunohistochemically detect expression of DKK1, vascular endothelial growth factor C (VEGF-C), and β-catenin. Prognostic significance was assessed using Kaplan-Meier survival estimates.

RESULTS

DKK1 expression was elevated in the Hep-2 cell line and tumor samples. DKK1 depletion decreased cell proliferation, migration, and invasiveness. High DKK1 expression was significantly associated with T and clinical stage, lymph node metastasis, and tumor size (p < 0.05). Increased DKK1 levels in LSCC tissues correlated with elevated VEGF-C and β-catenin. Multivariate analyses revealed that DKK1 was an unfavorable predictor of overall survival.

The radiosensitizing effect of the aurora kinase inhibitors, ENMD-2076, on canine mast cell tumours in vitro

ENMD-2076 is an aurora kinase inhibitor that also has multi-target tyrosine kinase inhibitor properties. In this study, the mRNA and the protein expression of aurora-A and aurora-B were evaluated in three canine mast cell tumour cell lines. Dose-dependent cytotoxicity was seen in the cells treated, and it affected the cell cycle with cells in the G2/M phase being selectively killed. The cells were also evaluated for radiosensitivity with/without ENMD-2076, and radiosensitization was seen after 3 Gy and 6 Gy exposures with ENMD-2076 for 48 h. Protein expression of caspase-3 was gradually increased, and the expression intensity was highest at 24 h post irradiation in cells without ENMD-2076 treatment, which indicates that radiation exposure with ENMD-2076-induced cell death faster than radiation treatment alone. Our study results suggest the potential usefulness of treating canine mast cell tumours with aurora kinase inhibitors alone or in conjunction with radiation therapy.

Relationship between anti-apoptotic proteins survivin and Bcl-2, and response to treatment in patients undergoing post-operative RT for laryngeal cancer: a pilot study

BACKGROUND

Clinicopathological research has focused on identifying molecular and biological prognostic factors for laryngeal carcinoma (LSCC) treated with post-operative radiotherapy (RT). The aim of this study was to assess the prognostic importance of anti-apoptotic proteins survivin and B-cell lymphoma-2 (Bcl-2) in a series of patients with LSCC who had primary surgery followed by RT.

METHODS

Thirty-three consecutive patients who underwent primary surgery followed by RT were considered. Survivin nuclear and cytoplasmic expressions and Bcl-2 expression were determined immunohistochemically.

RESULTS

The loco-regional recurrence rate was significantly higher among LSCC patients with a nuclear survivin expression >10.0% (P = 0.029), and their disease-free survival (DFS) was shorter than in cases whose nuclear survivin expression was ≤10.0% (P = 0.002). DFS was significantly shorter in cases with a Bcl-2 expression >2.0% than in those whose Bcl-2 expression was ≤2.0% (P = 0.035).

CONCLUSIONS

Nuclear survivin expression and Bcl-2 expression warrant further investigation as potential predictive biomarkers to enable individualized treatments (e.g. post-operative chemo-radiotherapy instead of RT alone for patients whose LSCCs strongly express nuclear survivin or/and Bcl-2). This preliminary evidence justifies the design of new studies on the association of agents targeting survivin and Bcl-2 with conventional chemotherapeutic agents and RT for advanced LSCC.

Mitotic failures in cancer: Aurora B kinase and its potential role in the development of aneuploidy

One of the basic requirements during the process of cell division is to maintain genetic integrity and ensure normal ploidy. The family of Aurora kinases, composed of Aurora A, B and C, takes a major role in the control of centrosome cycle, mitotic entry, chromosome condensation and coordination of chromosomal movements. Deregulation of kinase expression was described in a series of different malignancies which was also associated with aneuploidy. Recently, Aurora kinases gained significant interest as potential therapeutic targets in oncology. While there is increasing evidence about the activities of Aurora A kinase during cancer progression, data are controversial regarding the role of Aurora B. In this review the biology of Aurora kinases and its potential relation to cancer progression is discussed with special focus on functional changes and determination of Aurora B kinase.

Biologic therapy in head and neck cancer: a road with hurdles

The epidermal growth factor receptor (EGFR) is overexpressed in the vast majority of cases of squamous cell carcinoma of the head and neck (SCCHN). A high EGFR expression is associated with an unfavorable prognosis. Cetuximab is a chimeric human/murine IgG1 antibody which binds with high affinity to the EGFR. It is the only targeted agent which got approval for the treatment of SCCHN from the regulatory agencies of Europe and the United States, both in locoregionally advanced disease, in association with radiation, and in recurrent/metastatic disease. The outcome of trials involving other EGFR-directed monoclonal antibodies, that is, zalutumumab and panitumumab, was consistent with the results with cetuximab. However these trials failed to meet their primary endpoint. The results with EGFR-directed tyrosine kinase inhibitors have been disappointing. Other potential targets for treatment in SCCHN include the entire ErbB family, the vascular endothelial growth factor (VEGF) and its receptor (VEGFR), the insulin-like growth factor 1 receptor (IGF-1R), the insulin receptor (IR), histone deacetylases (HDAC), the mammalian target of rapamycin (mTOR), the platelet-derived growth factor receptor (PDGFR), heat-shock protein 90 (HSP90), nuclear factor-kappa B (NF-κB), aurora A or B, and phosphatidylinositol 3-kinase (PIK3CA).