RESUMO
<p><b>OBJECTIVE</b>To study the expression of miRNA-106a gene in esophageal squamous cell carcinoma (ESCC) and its association with clinicopathological features and prognosis of ESCC patients.</p><p><b>METHODS</b>Real-time fluorescence quantitative polymerase chain reaction (PCR) assay was used to determine the expression of miRNA-106a gene in esophageal cancer tissue and corresponding normal mucosa of 81 cases. Immunohistochemical technique was applied to detect the expression of p53, human epidermal growth factor receptor 2 (HER-2), DNA topoisomerase II (Topo II) and multidrug resistance-associated protein (MRP). The association of miRNA-106a expression with clinicopathological features, expression of related proteins, and prognosis of the patients was analyzed.</p><p><b>RESULTS</b>Among the 81 cases, under-expression of miRNA-106a gene was found in 48 cases (59.3%), normal expression in 22 cases (27.2%), and overexpression in 11 cases (13.6%). The expression of miRNA-106 gene was significantly associated with lymph node metastasis, pathological stage, and nerve invasion (all P < 0.05), significantly associated with expression of p53 (P = 0.006), and not significantly associated with expressions of HER-2, Topo II and MRP proteins (all P > 0.05). The expression of miRNA-106a gene was also significantly associated with progression-free survival (PFS, P = 0.032), but not significantly with overall survival (OS, P = 0.486). The results of Cox multivariate regression analysis showed that the PFS of ESCC patients was significantly correlated with lymph node metastasis (P = 0.029), but not correlated with the age, gender, tumor length, T stage, degree of differentiation, nerve invasion, and miRNA-106a expression (all P > 0.05).</p><p><b>CONCLUSIONS</b>In esophageal squamous cell carcinomas, the miRNA-106a gene is under-expressed, with tumor suppressor function, and may be regarded as a biological marker to assess the prognosis in patients with esophageal squamous cell carcinoma.</p>