Aurora kinase B inhibition reduces the proliferation of metastatic melanoma cells and enhances the response to chemotherapy

BACKGROUND

The poor response to chemotherapy and the brief response to vemurafenib in metastatic melanoma patients, make the identification of new therapeutic approaches an urgent need. Interestingly the increased expression and activity of the Aurora kinase B during melanoma progression suggests it as a promising therapeutic target.

METHODS

The efficacy of the Aurora B kinase inhibitor barasertib-HQPA was evaluated in BRAF mutated cells, sensitive and made resistant to vemurafenib after chronic exposure to the drug, and in BRAF wild type cells. The drug effectiveness has been evaluated as cell growth inhibition, cell cycle progression and cell migration. In addition, cellular effectors of drug resistance and response were investigated.

RESULTS

The characterization of the effectors responsible for the resistance to vemurafenib evidenced the increased expression of MITF or the activation of Erk1/2 and p-38 kinases in the newly established cell lines with a phenotype resistant to vemurafenib. The sensitivity of cells to barasertib-HQPA was irrespective of BRAF mutational status. Barasertib-HQPA induced the mitotic catastrophe, ultimately causing apoptosis and necrosis of cells, inhibited cell migration and strongly affected the glycolytic metabolism of cells inducing the release of lactate. In association i) with vemurafenib the gain in effectiveness was found only in BRAF(V600K) cells while ii) with nab-paclitaxel, the combination was more effective than each drug alone in all cells.

CONCLUSIONS

These findings suggest barasertib as a new therapeutic agent and as enhancer of chemotherapy in metastatic melanoma treatment.

The role of chemotherapy in the modern management of melanoma

The last 4 years have seen dramatic changes in the treatment of advanced melanoma, largely based on advances in targeted therapy and immunotherapy. This article examines the role of chemotherapy in the modern management of melanoma. We examine the evidence for promising new agents and discuss their position in the sequencing of treatment options for patients with advanced disease. In addition, we discuss the combination of chemotherapy with targeted treatments and immune therapies. Finally, we discuss future areas of research for ensuring that we maximize the potential of all agents available to us and identify new, effective treatments.

A review of novel therapies for melanoma

This review summarizes results from major recent trials regarding novel therapeutic agents in melanoma. The topics discussed include targeted therapy with BRAF (V-RAF murine sarcoma viral oncogene homolog B) inhibitors (vemurafenib and dabrafenib), MEK (mitogen-activated protein kinase kinase) inhibitors (trametinib), bcr-abl/c-kit/PDGF-R inhibitors (imatinib), and angiogenesis inhibitors (bevacizumab and aflibercept), as well as immunotherapy with anti-CTLA-4 (anti-cytotoxic T-lymphocyte antigen-4) antibodies (ipilimumab), anti-PD (anti-programmed death receptor) antibodies (nivolumab and lambrolizumab), and anti-PD-L (anti-programmed death ligand) antibodies. Various combinations of these agents, as well as adjunctive GM-CSF (granulocyte-macrophage colony-stimulating factor), T-VEC (talimogene laherparepvec) oncolytic viruses, and novel chemotherapeutic agents, are also described. Despite the tremendous advances that these novel treatments have created, optimal therapeutic agent selection remains a highly individualized decision. Melanoma therapy has vastly progressed since the days when dacarbazine was the sole option for advanced melanoma patients. The molecular understanding of melanoma pathogenesis has yielded a brighter future for advanced melanoma patients.

Correlation of BRAF and NRAS mutation status with outcome, site of distant metastasis and response to chemotherapy in metastatic melanoma

BACKGROUND

The prognostic significance of BRAF and NRAS mutations in metastatic melanoma patients remains uncertain, with several studies reporting conflicting results, often biased by the inclusion of patients treated with BRAF and MEK (MAPK) inhibitors. We therefore interrogated a historical cohort of patients free of the confounding influence of MAPK inhibitor therapy.

METHODS

Patients with available archival tissue first diagnosed with metastatic melanoma between 2002 and 2006 were analysed. Mutational analysis was performed using the OncoCarta Panel. Patient characteristics, treatment outcome and survival were correlated with BRAF/NRAS mutation status.

RESULTS

In 193 patients, 92 (48%) melanomas were BRAF-mutant, 39 (20%) were NRAS-mutant and 62 (32%) were wild-type for BRAF/NRAS mutations (wt). There was no difference in response to chemotherapy based on mutation status (35-37%). The distant disease-free interval (DDFI) was significantly shorter in patients with wt melanoma (27.9 months vs 35.1 for BRAF and 49.1 for NRAS) although this was not significant in multivariate analysis. Survival from stage IV melanoma diagnosis was not significantly different based on mutation status. The DDFI was significantly shorter in patients with BRAF(V600K/R) versus BRAF(V600E) melanoma in univariate and multivariate analyses.

CONCLUSIONS

BRAF and NRAS mutation status does not influence survival in metastatic melanoma.