Functional characterization of melanoma upregulated long noncoding RNA SPRY4‐IT1

Abstract

The elevated expression of SPRY4‐IT1 in melanoma cells compared to melanocytes, its accumulation in cell cytoplasm, and its effects on cell dynamics, including increased rate of invasion, proliferation and motility, suggest that the higher expression of SPRY4‐IT1 may have an important role in the molecular etiology of human cancers. To identify the molecular mechanism of SPRY4‐ IT1, we have engineered human melanocytes to ectopically express SPRY4‐IT1 and engineered cells were assayed to identify genes and proteins expression changes compared to vector only cells. The results indicate that the modulation of a sub‐group of anti‐apoptotic and cell cycle genes. We have also observed that SPRY4‐ IT1 is associated with the appearance of multinucleated giant cells and increases cell proliferation and invasion in engineered melanocytes. RNA‐FISH probes that were designed to various regions (5′ and 3′) of SPRY4‐IT1 demonstrate the existence of a 5′ excision event during the RNA processing and 5′RACE and Northern‐blot analysis confirmed these results. The characterization of RNA from monosome and polysome fractions followed by qRT‐PCR and Northern blots demonstrates that SPRY4‐IT1 is predominantly transported in to the polysome fractions. SPRY4‐IT1 molecular function, transcriptional regulation, cellular compartmentalization, and its interaction with other RNAs and proteins will be discussed.