Expression data from normal melanocyte, melanoma cells and their exosomes (microRNA)

Exosomes are small membraneous vesicles secreted into body fluids by tumors. Tumor exosomes contain intact and functional mRNAs, small RNAs (including miRNAs), and proteins that can alter the cellular environment to favor tumor growth. Further exploration into the molecular profiling of exosomes may increase our understanding of their roles in melanoma progression in vivo, and may have potential application in biomarker studies. In the present study, we used mRNA array profiling to identify thousands of exosomal mRNAs associated with melanoma progression and metastasis. Similarly, miRNA array profiling identified specific miRNAs, such as hsa-miR-31, -185, and -34b, involved in melanoma invasion. Our results indicate that melanoma-derived exosomes have unique gene expression signatures and miRNA profiles that may have important functions in melanoma metastasis and progression. Total RNA from cells and exosomes were isolated using mirVana total RNA isolation kit according to the manufacturer’s guidelines. RNA was quantified using Nanodrop ND-1000. The integrity of these total RNAs was assessed using Agilent 2100 Bioanalyzer. Total high-quality RNA was labelled. The miRNA array profiling was performed by using the Affymetrix GeneChip miRNA Array 1.0. Two different RNA preparations from two cell lines and their exosomes were used, except that only one RNA preparation was used for HEMa-LP exosome miRNA array. Due to the limited number of passages (approximately 10), adequate exosomal RNA and proteins from HEMa-LP cells for multiple analyses was not available.