Prognostic implications for high expression of oncogenic microRNAs in advanced gastric carcinoma

BACKGROUND: Aberrant expressions of specific microRNAs are recently known in many malignancies, including gastric carcinoma. The prognostic implication of oncogenic microRNA dysregulation was investigated in advanced gastric carcinomas undergoing radical resection and adjuvant systemic chemotherapy, and observed on long-term follow-up. METHODS: The expression levels of miR-20a, miR-21, miR-25, miR-93, miR-103, miR-106a, miR-106b, miR-130b, miR-155, miR-221, and miR-222 were analyzed in formalin-fixed paraffin-embedded (FFPE) cancer tissues of 91 patients, using reverse transcription real-time PCR. RESULTS: The high expression of miR-20a, miR-25, miR-93, miR-103, miR-106a, miR-106b, miR-130 was associated with lymph node metastasis (P < 0.05), and high expression of miR-155 was related to tumor penetration through serosa and lymph node metastasis (P < 0.05). Cases with high expression of miR-222 (P = 0.014) showed reduced 5-year survival rates. The high expression of miR-222 and miR-221 showed correlation with shorter metastasis-free survival (P = 0.039 and 0.033, respectively), and miR-222 high expression was related to reduced overall survival (P = 0.012). CONCLUSIONS: The high expression of miR-20a, miR-25, miR-93, miR-103, miR-106a, miR-106b, miR-130, miR-155, miR-221, and miR-222 in AGC tissues may be a high risk factor associated with tumor penetration through serosa, lymph node metastasis, distant metastasis, and poor long-term survival in patients undergoing radical resection and adjuvant systemic chemotherapy.