Mir-148a Improves Response to Chemotherapy in Sensitive and Resistant Oesophageal Adenocarcinoma and Squamous Cell Carcinoma Cells

Background Response to chemotherapy varies widely in patients with advanced oesophageal cancer. We investigated the impact of manipulating certain microRNAs on response to cisplatin and 5-fluorouracil (5-FU) in oesophageal cancer cells. Methods Cisplatin-/5-fluorouracil-resistant oesophageal squamous cell carcinoma (SCC) and adenocarcinoma (EAC) cell lines were established, and the impact of ectopic upregulation of miR-106a and miR-148a on response to both drugs was assessed. Results The impact of miR-106a-upregulation was inconsistent. Upregulation was followed by reduced sensitivity to cisplatin in chemotherapy-sensitive EAC cells (cell survival, +8.7 +/- 0.8%; p = 0.003) and an improved response to 5-FU in cisplatin-resistant EAC cells (cell survival, -6.4 +/- 2.5%; p = 0.011). MiR-148a upregulation significantly increased sensitivity to chemotherapy in seven out of ten cell lines, represented by a decrease in cell viability of 22.6 +/- 7.9% to 50.5 +/- 10.6% after cisplatin (p <= 0.014) and 6.0 +/- 0.8% to 15.0 +/- 4.1% after 5-FU treatment (p <= 0.012). The only cell lines in which miR-148a upregulation had no effect were cisplatin-resistant EAC exposed to cisplatin and 5-FU-sensitive and 5-FU-resistant SCC cells exposed to 5-FU. Conclusion MiR-148a sensitized chemotherapy-sensitive oesophageal cancer cell lines to cisplatin and, to a lesser extent, to 5-flurouracil and attenuated resistance in chemotherapy-resistant variants. Further experimental and clinical studies to investigate the exact mechanisms involved are warranted.