Analysis of variance (ANOVA) was used for miRNA selection from the miRNA microarray study. P<0.05 was considered statistically significant. Results miRNA expression profiles of gastric cancer tissues and the corresponding metastatic lymph node tissues In this study, we first profiled differentially expressed miRNAs between gastric cancer and the corresponding metastatic lymph node tissues. After profiling three cases of paired tissue samples (the pathology of these cancer tissues is listed in Additional file 1: Figure S1), we found 151 upregulated miRNAs (≥1.5-fold; Additional file 2: Table S1) and 285 downregulated miRNAs CH5183284 in vitro (≤0.67-fold)

in the metastatic tissues compared to the primary gastric cancer tissues (Additional file 2: Table S1). Specifically, expression of hsa-miR-508-5p, hsa-miR-483-5p, hsa-miR-134, hsa-miR-30c, and hsa-miR-337-3p was reduced in all three metastatic cancer tissues. Thus, we selected these five miRNAs for further confirmation (Table 1) and found that expression of hsa-miR-337-3p and miR-508-5p was four times greater

in the primary cancer tissues compared to the metastatic gastric cancer tissues, while miR-483-5p expression was 2.6 times greater, miR-30c expression was 2.14 times greater, and miR-134 expression www.selleckchem.com/Proteasome.html was 4.9 times greater in the primary cancer tissues compared to the metastatic gastric cancer tissues (Table 1). Loss of hsa-miR-337-3p and hsa-miR-134 expression in metastatic lymph node tumors Next, we verified these five selected miRNAs in 16 pairs of primary and secondary gastric cancer tissues crotamiton using qRT-PCR. Our data showed differential expression of hsa-miR-508-5p, hsa-miR-483-5p, hsa-miR-134, hsa-miR-30c, and hsa-miR-337-3p in these 16 paired samples (Figure 1), while expression Smoothened inhibitor levels of hsa-miR-337-3p and hsa-miR-134 were significantly reduced in the metastatic tissues compared to the primary gastric cancer tissues (Table 1). Figure 1 hsa-miR-508-5p, hsa-miR-483-5p, hsa-miR-134, hsa-miR-30c, and hsa-miR-337-3p in primary gastric cancer

and the corresponding metastatic lymph node tissue. Differential expression of hsa-miR-508-5p (A), hsa-miR-483-5p (B), hsa-miR-134 (C), hsa-miR-30c (D), and hsa-miR-337-3p (E) in 16 paired samples of primary gastric cancer (GC) and the corresponding metastatic lymph node tissues (LN) as determined by qRT-PCR. The values shows the fold change of the expression level of LN versus GC (n=3). Expression of hsa-miR-134 and hsa-miR-337-3p in nonmalignant gastric cells and gastric cancer cells To determine the potential role of hsa-miR-134 and hsa-miR-337-3p in gastric cancer, we assessed their expression in a nonmalignant gastric cell line (GES) and nine gastric cancer cell lines (SNU-1, SNU-5, AGS, HGC-27, BGC-823, MGC-803, SGC-7901, MKN-28, and MKN-45) using qRT-PCR.