MicroRNA expression profiling of small-intestine neuroendocrine tumors and human neuroendocrine tumor cell lines

Small intestinal neuroendocrine tumors (SI-NETs) arise from serotonin-producing enterochromaffin cells. SI-NETs are often well-differentiated tumors and most patients have regional or distant metastases at initial presentation. MicroRNAs (miRs) are post-transcriptional regulators which are important in diverse biological processes and can function as tumor suppressor genes or oncogenes. This study aims to identify an exclusive SI-NETs miR profile that may have a critical role in development, diagnosis, prognosis and progression of these malignancies. Five human NET cell lines, one octreotide-treated CNDT2.5 cells, one microdissected normal enterochromaffin cells, three snap-frozen normal ileum specimens and 15 SI-NET specimens at different stage of malignancy, five primary tumors, five mesentery metastases and five liver metastases, were included in this study. Total RNA was hybridized onto Affymetrix GeneChip® miR arrays for genome-wide profiling. Array data summarization, normalization, and quality control were performed using miRNA QC Tool software.