A comparative transcriptomic analysis of uveal melanoma and normal uveal melanocyte

Uveal melanoma is the most common primary intraocular tumor in adults in western countries. It is associated with very severe visual morbidity and may lead to distant metastases even after successful treatment of the primary tumor. In order to gain better insight into molecular mechanisms related to tumorigenesis and metastasis of uveal melanoma, we used next-generation sequencing technology (SOLiD, Life Technologies) to acquire global transcriptome alteration between posterior uveal melanoma cells and normal uveal melanocyte.

From mRNAs of the cultured uveal melanoma cells and normal uveal melanocytes, we annotated more than 3.7 × 10(7) and 2.7 × 10(7) sequencing tags based on human Ensembl databases, respectively. For detailed analysis, we chose 5155 well-annotated genes mainly involved in the MAPK signaling pathway, cell cycle, cell adhesion junction, apoptosis, and P53 signaling pathways as well as melanogenesis. In an effort to confirm the authenticity of our sequencing results, we validated twenty-one identically differentially expressed genes by using quantitative real time PCR from cultured cell lines of other posterior uveal melanoma cells and normal uveal melanocytes.

We have identified a large number of potentially interesting genes for biological investigation of uveal melanoma. The expression profiling also provides useful resources for other functional genomic and transcriptome studies. These 21 potential genes could discriminate between uveal melanoma cells and normal uveal melanocyte, which may be indicative of tumorigenesis process. Our results further suggest that high-throughput sequencing technology provides a powerful tool to study mechanisms of tumogenesis in the molecular level.