Background: It is urgent to find some biochemical markers for predicting the radiochemotherapy sensitivity. microRNAs have a huge potential as a predictive biomarker in gastric cancer. The current study aims to identify the microRNAs related to the radiochemotherapy sensitivity in gastric cancer.
Methods: From April 2012 to August 2014, 40 patients with locally advanced gastric cancer were included into the clinical trial in the Fudan University Shanghai Cancer Center. The lesion specimens of 15 patients were obtained by gastroendoscopy before treatment, and the RNA was extracted. microRNAs array was used to identify the microRNAs with different expression level between sensitive group and non-sensitive group. The microRNAs identified in the array were further confirmed by TaqMan Real-time PCR.
Results: 2006 microRNAs were identified by microRNA array, including 302 highly expressed microRNAs and 1704 lowly expressed microRNAs between non-sensitive group and sensitive group. According to the statistical significance (p < 0.05) and expression level (more than twofold or less than 0.5 times), 9 microRNAs were identified. Finally, we chose 6 microRNAs like miR-16-2-3p, miR-340-5p, miR-338-3p, miR-142-3p, miR-142-5p and miR-582-5p to determine the sensitive group and non-sensitive group. TaqMan Real-time PCR confirmed the results of microRNA array.
Conclusions: microRNA array can be used to select the microRNAs associated with radiochemotherapy sensitivity in gastric cancer. miR-338-3p and miR-142-3p may be promising predictive biomarkers for such patients.
Trial registration: Trial Registration number: NCT03013010 . Name of registry: Phase II Study of Neoadjuvant Chemotherapy Wtih S1 + Oxaliplatin (SOX) Regimen Followed by Chemoradiation Concurrent With S-1 in Patients With Potentially Resectable Gastric Carcinoma. Date registered: December 31, 2013. The trial was prospectively registered.
Keywords: Gastric cancer; Preoperative radiochemotherapy; Response; microRNAs expression.