MicroRNA-profiling in breast- and salivary gland-derived adenoid cystic carcinomas

INTRODUCTION: Adenoid cystic carcinoma is a salivary gland-derived malignant tumor, but rarely it can originate from the breast, too. The salivary gland-derived form shows a very aggressive clinical outcome, while adenoid cystic carcinoma of the breast has mostly a very good prognosis. AIM: The aim of the authors was to compare the miRNA-expression profile of breast- and salivary gland-derived cases. METHOD: The miRNA-profiles of two salivary gland derived and two breast-derived adenoid cystic carcinoma tissues as well as one normal breast and one salivary gland tissues were analysed using the Affymetrix® Gene Chip. RESULTS: The expression of some miRNAs differed in the tumor tissues compared to their controls: the let-7b was overexpressed in salivary gland-derived adenoid cystic carcinoma, while decreased in breast-derived adenoid cystic carcinoma. In addition, the miR-24 was decreased in salivary gland-derived but overexpressed in breast-derived adenoid cystic carcinomas. The miR-181a-2* was only detected in salivary gland-derived adenoid cystic carcinomas. CONCLUSIONS: Through post-transcriptional regulation of the genes, the diverse expression of some miRNAs may partially explain the diverse clinical outcome of salivary gland-derived and breast-derived adenoid cystic carcinomas.