Somatostatin (SST) analogues are used to control the proliferation and symptoms of
neuroendocrine tumors (NETs).
MicroRNAs (
miRNA) are small non-coding RNAs that modulate posttranscriptional gene expression. We wanted to characterize the
miRNAs operating under the control of SST to elucidate to what extent they mediate STT actions. NCI-H727
carcinoid cell line was treated with either a chimeric SST/
dopamine analogue; a SST or
dopamine analogue for proliferation assays and for identifying differentially expressed
miRNAs using
miRNA microarray. The
miRNAs induced by SST analogue treatment are investigated in
carcinoid cell lines NCI-H727 and CNDT2 using in situ hybridization, qPCR and proliferation assays. SST analogues inhibited the growth of
carcinoid cells more potently compared to the
dopamine analogue. Principal Component Analysis (PCA) of the samples based on
miRNA expression clearly separated the samples based on treatment. Two
miRNAs which were highly induced by SST analogues, miR-7 and miR-148a, were shown to inhibit the proliferation of NCI-H727 and CNDT2 cells. SST analogues also produced a general up-regulation of the let-7 family members. SST analogues control and induce distinct
miRNA expression patterns among which miR-7 and miR-148a both have growth inhibitory properties.