EPHA2 inhibition reverts epithelial-mesenchymal transition (EMT) phenotype and reduces proliferation of colorectal cancer cells

OBJECTIVE: The Eph-Ephrin system is involved on different biological cellular processes, but at the same time, reveals to be an important player on tumor progression including colorectal cancer cells. High levels of EphA2 are observed on colorectal cancer cells compared to normal counterpart. This is associated with a worse prognosis and a more invasive and metastatic behaviour. Furthermore, EphA2 promotes and supports the EMT, making tumor cells more aggressive. The aim of the study is the evaluation of the anti-tumor effects of a tyrosine kinase EphA2 inhibitor on a cohort of five colorectal cancer cells in vitro. MATERIALS AND METHODS: We analyzed antitumor effects of this compound performing growth analysis by direct cell count, MTT assay and FACS analysis. Western blot assay were performed for the evaluation of EMT phenotype by using antibody against E-cadherin (negative EMT marker), survivin, "-catenin, SNAIL, c-myc and PCNA. RESULTS: EphA2 inhibition reduces significantly the growth of colorectal cancer cells. We selects two models of tumor cells: HCT115 (Kras wild type) and HCT116 (Kras mutated) to perform western blot. Analyses of cell cycle reveals an accumulation of cells in G0/G1 phase and a reduction of G2/M phase. Few apoptosis was observed. Major effects were, indeed, observed in the EMT reversion and growth inhibition with strong enhance in E-cadherin expression, and reduction of PCNA, survivin, "-catenin, c-myc and SNAIL. CONCLUSIONS: In our knowledge, this work, for the first time, evaluates the effects of tyrosine kinase EphA2 inhibition on colorectal cancer cell models. Our data are in agreement with previous studies stating that EphA2 signaling correlates with tumor aggressiveness and progression. Further in vitro and in vivo investigations are, however, necessary to better elucidate the overall involved molecular arrangements.