Synergistically Anti-metastatic Effect of 5-Flourouracil on Colorectal Cancer Cells via Calcium-mediated Focal Adhesion Kinase Proteolysis

• Published in: Anticancer research 2017-01, Vol.37 (1), p.103-114
• Main Authors: Park, Minhee, Sundaramoorthy, Pasupathi, Sim, Jae Jun, Jeong, Keun-Yeong, Kim, Hwan Mook
• Format: Article
• Language: English
• Subjects: Antineoplastic Combined Chemotherapy Protocols - pharmacology; Biomarkers, Tumor - metabolism; Calcium Compounds - pharmacology; Cell Death - drug effects; Cell Movement - drug effects; Cell Proliferation - drug effects; Colorectal Neoplasms - drug therapy; Colorectal Neoplasms - enzymology; Colorectal Neoplasms - pathology; Dose-Response Relationship, Drug; Drug Synergism; Epithelial-Mesenchymal Transition - drug effects; Fluorouracil - pharmacology; Focal Adhesion Kinase 1 - metabolism; HCT116 Cells; HT29 Cells; Humans; Lactates - pharmacology; Neoplasm Invasiveness; Neoplasm Metastasis; Proteolysis; Signal Transduction - drug effects; Time Factors
• ISSN: 0250-7005; 1791-7530
• DOI: 10.21873/anticanres.11295

To investigate the possibility of enhancing an anti-metastatic effect of 5-fluorouracil (5-FU) on colorectal cancer (CRC) cells by combining it with continuous calcium supplementation. Optimal doses of 5-FU with/without lactate salt (CaLa) were determined via clonogenicity and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays using human CRC cells cultured on normal or low-attachment plates. Invasion and migration assays confirmed the enhanced anti-metastatic effect of combining 5-FU and CaLa. Western blot analysis for elements of the focal adhesion kinase (FAK) signaling cascade and epithelial-mesenchymal transition (EMT) markers was used to investigate the underlying mechanism. 5-FU (2.5 μM) had no antitumor activity against unanchored CRC cells, while it significantly suppressed anchorage-dependent cell proliferation. In contrast, treatment with CaLa (2.5 mM), alone and in combination with 5-FU, exerted antitumor activity against both anchored and unanchored CRC cells via calcium-mediated FAK proteolysis and inhibition of EMT markers, such as vimentin and SNAIL. Calcium supplementation represents a method of enhancing the potency of existing antitumor agents such as 5-FU, augmenting their clinical effectiveness.