Background:
The high load of UV signature DNA mutations found in melanomas is evidence of not only the role of UV in melanomagenesis but also of a defect in repair of UV-induced lesions. We have previously identified a G2 phase cell cycle checkpoint and repair response to low-dose UVB that is commonly defective in melanoma cell lines. Here we aim to identify the components of the checkpoint and repair pathways involved in this UV-induced response.
Methods:
We have investigated the global alterations in: transcription; translation; protein abundance; and microRNAs associated with the UV response. We have used two model systems previously characterised for the UV-induced G2 delay, an A2058 melanoma cell line model and a whole skin organ culture model. Total mRNA and polysome mRNA were analysed using Illumina whole genome microarrays, microRNAs were analysed by RNA-seq, and protein changes were analysed by SILAC proteomics.
Results:
Data was combined from these analyses to identify a set of 45 high probability candidates, and 11 UV-responsive mircroRNAs potentially contributing to this response. Candidates are being further examined using high-throughput functional analyses, to determine their involvement in the normal UV response. A summary of ongoing work characterising the UV response will be presented.
Conclusions:
Once the mechanisms of the normal UV response have been characterised, we can identify defects in the normal surveillance, checkpoint and/or repair mechanisms which allow escape of UV-induced mutations. This may offer opportunities to expand diagnostic (and potentially therapeutic) options for melanoma patients.