CCT-137690

Dysregulation of the cell cycle is one of the main causes of melanomagenesis. Genomewide studies showed that the expression of Aurora -A and -B significantly has been upregulated in melanoma. However, there is no FDA approved drug targeting aurora kinases in the treatment of melanoma. In addition, the development of resistance to chemotherapeutic agents in the treatment of melanoma and, as a result, the relapse due to heterogeneous cell groups in patients is a second phenomenon that causes treatment failure. Therefore, there is an urgent need for therapeutic alternatives targeting both melanoma and Melanoma Cancer Stem Cells (MCSCs) in treatments. At this stage, cell cycle regulators become promising targets.

In this study, we aimed to identify the effects of Aurora kinase inhibitor CCT137690 on the cytotoxicity, apoptosis, cell cycle, migration, and colony formation and expression changes of genes related to proliferation, cell death and cell cycle in melanoma and melanoma cancer stem cell. In addition, we investigated the apoptotic and cytostatic effects of CCT137690 in normal fibroblast cells.

We evaluated the cytotoxic effect of CCT137690 in MCSCs, NM2C5 referring as melanoma model cells and WI-38 cells by using the WST-1 test. The effect of CCT137690 on apoptosis was detected via Annexin V and JC-1 method; on cell cycle progression by cell cycle test; on gene expression by using RT-PCR, on migration activity by wound healing assay and clonal growth by clonogenic assay in NM2C5 cells and MCSCs. The effects of CCT137690 in WI-38, referring as healthy fibroblast cell, were assessed through Annexin V and cell cycle method.

CCT137690 was determined to have a cytotoxic and apoptotic effect in MCSCs and melanoma. It caused polyploidy and cell cycle arrest at the G2/M phase in MCSCs and melanoma cells. The significant decrease in the expression of MMP2, MMP7, MMP10, CCNB1, IRAK1, PLK2 genes, and the increase in the expression of PTEN, CASP7, p53 genes were detected.

Aurora kinases inhibitor CCT137690 displays promising anticancer activity in melanoma and especially melanoma cancer stem cells. The effect of CCT137690 on melanoma and MCSC may provide a new approach to treatment protocols.

Oral cancer is the most prevalent subtype of head and neck cancers and arises mainly from squamous cells of the oral cavity. Patients with advanced metastatic disease have poor overall survival resulting primarily from limited treatment options. Recent advances in the understanding of molecular basis of oral tumorigenesis provide an opportunity for identification and validation of new drug targets. The deregulated expression of the Aurora family of mitotic kinases, for example, has been associated with pathogenesis and poor prognosis in oral cancer. Here, we have evaluated the efficacy of the pan-Aurora inhibitor (CCT137690) alone and in combination with different chemotherapeutic and targeted drugs to identify its synergistic partners in oral cancer cell lines (ORL-48 and ORL-115). CCT137690 effectively inhibits Aurora kinases in both the cell lines and displays potent antiproliferative activity towards them. Prolonged treatment of these cells with CCT137690 results in abrogated mitotic spindle formation, misaligned chromosome attachment and polyploidy that ultimately leads to apoptotic cell death. We further identified that inhibitors of EGFR (gefitinib) and PI3-kinase (pictilisib) synergize with CCT137690 to inhibit the proliferation of the oral cancer cell lines. Moreover, we demonstrate that polyethylene glycol-based nanocapsules harboring combinations of CCT137690 with gefitinib or pictilisib inhibit the growth of oral cancer cell lines in 3D spheroid cultures and induce apoptosis that is comparable to free drug combinations. In conclusion, we have demonstrated the in vitro efficacy of CCT137690 in oral cancer cell lines, identified novel drug combinations with CCT137690 and synthesized nanocapsules containing these drug combinations for co-administration.