ABSTRACT
<p><b>OBJECTIVE</b>Gastrointestinal stromal tumors (GISTs) have a broad spectrum of biological behaviors ranging from benign, borderline and malignant. This study aimed to screen differentially expressed microRNAs (miRNAs) between malignant and borderline GISTs and to investigate the potential role of miRNAs in the malignant transformation of GISTs.</p><p><b>METHODS</b>Six GIST samples including borderline tumors (n = 3) and malignant tumors (n = 3) were collected based on the clinical and pathological characteristics. Total RNA was extracted, followed by miRNA microarray analysis to screen the differentially expressed miRNAs. The most significantly expressed 4 miRNAs were then chosen for further validation by real-time PCR in 22 additional GIST samples.</p><p><b>RESULTS</b>Direct comparison of malignant group versus borderline group revealed 14 significantly and differentially expressed miRNAs (P < 0.05, with a fold change of < 0.5 or > 2). Five miRNAs were up-regulated and nine were down-regulated in the malignant group. Four miRNAs (miR-221, miR-135b, miR-675(*) and miR-218) were most significantly and differentially expressed between the two groups. The differential expression of 2 miRNAs (miR-221 and miR-675(*)) were subsequently confirmed with good concordance by real-time PCR.</p><p><b>CONCLUSIONS</b>The differential miRNA expression profiles between two groups are revealed by miRNA microarray assay, and confirmed by real-time PCR. Among differentially expressed miRNAs, miR-221 and miR-675(*) might be related to the malignant transformation of GISTs, and have a potential value in predicting biological behavior of GISTs.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cell Transformation, Neoplastic , Down-Regulation , Gastrointestinal Neoplasms , Genetics , Pathology , Gastrointestinal Stromal Tumors , Genetics , Pathology , Gene Expression Profiling , MicroRNAs , Genetics , Metabolism , Microarray Analysis , Real-Time Polymerase Chain Reaction , Up-RegulationABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinicopathological and molecular genetic characteristics of gastrointestinal stromal tumor (GISTs) with significant cystic changes, and to assess their biological behavior.</p><p><b>METHODS</b>Clinicopathological features of 7 patients with cystic GISTs treated at the Zhongshan Hospital of Fudan University from February 2005 to January 2010 were summarized retrospectively. The mutations status of c-kit and PDGFR-α were analyzed.</p><p><b>RESULTS</b>There were 2 males and 5 females aged from 46 to 76 years old. Primary site of GISTs included stomach(n=4), duodenum(n=1), and small intestinal(n=2). Tumor size ranged from 6 to 16 cm with obviously cystic changes. Tumor cells were found in the solid components under microscope, of which epithelioid cell type were found in 4 case and spindle cell type in 3 cases. The mitotic figures were no more than 3/50 HPF in all the patients. According to the NIH criteria, 4 were high-risk and 3 were low-risk. Based on morphological characteristics, 3 cases were as borderline tumor, 3 moderate-risk, and 1 moderate-risk. Gene mutation of exon 11 of c-kit were identified in 3 cases. During the follow up ranging from 9 to 80 months, all the 7 patients had cancer-free survival.</p><p><b>CONCLUSION</b>The biological behavior of cystic GIST is indolent with a low risk of malignancy and favorable prognosis.</p>