Lab
Hurlstone Lab
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Statement of Research Interest
The main focus of my group is tumour biology. In particular, we focus on chemotherapy resistance in cancer and factors underlying malignant conversion. Our chosen model is the zebrafish and we manipulate this organism using mutagenesis, transgenesis, antisense oligonucleotides, and small molecule inhibitors. Using these methods, we have developed several tumour models including melanoma and intestinal tumours, and are now validating the role of certain protein targets (implicated through transcription profiling and data mining) in therapeutic resistance and/or disease progression.
To illustrate our strategy, we have recently targeted expression of human oncogenic RAS to zebrafish melanocytes. This has given rise to a model of melanoma, both sporadic and familial. At the same time through expressing oncogenic BRAF, we have generated a model of benign melanocyte neoplasia. Moreover, through simultaneously expressing RAS and an inhibitor of the PI3K signalling pathway (a truncated form of the PI3K regulatory protein p85), we have demonstrated the importance of PI3K signalling in the progression of melanocyte neoplasia to malignancy. Comparing the transcriptomes of melanocytes with these different genotypes is revealing interesting patterns of diffferential gene expression that correlate with disease state. Analysis of these altered states of gene expression is implicating deregulated developmental signalling and inflammation in melanoma disease progression.
The above gene expression analysis is also supplying us with candidates to pursue to target melanoma. We have demonstrated that melanoma initiates in RAS-expressing animals soon after fertilisation. At this time-point animals are very amenable to targeted knockdown of gene products using both antisense oligonucleotides as well as small molecule inhibitors. We have developed a simple, sensitive and robust spectrophotometric assay for quantifying the extent of neoplasia in transgenic larval zebrafish, and have demonstrated that targeted knockdown of MAPK, PI3K and TOR signalling components antagonizes melanoma development. Reversing the logic of this approach implies that this in vivo assay could be used to discover novel antineoplastic compounds, something we would like to demonstrate in the near future.
To illustrate our strategy, we have recently targeted expression of human oncogenic RAS to zebrafish melanocytes. This has given rise to a model of melanoma, both sporadic and familial. At the same time through expressing oncogenic BRAF, we have generated a model of benign melanocyte neoplasia. Moreover, through simultaneously expressing RAS and an inhibitor of the PI3K signalling pathway (a truncated form of the PI3K regulatory protein p85), we have demonstrated the importance of PI3K signalling in the progression of melanocyte neoplasia to malignancy. Comparing the transcriptomes of melanocytes with these different genotypes is revealing interesting patterns of diffferential gene expression that correlate with disease state. Analysis of these altered states of gene expression is implicating deregulated developmental signalling and inflammation in melanoma disease progression.
The above gene expression analysis is also supplying us with candidates to pursue to target melanoma. We have demonstrated that melanoma initiates in RAS-expressing animals soon after fertilisation. At this time-point animals are very amenable to targeted knockdown of gene products using both antisense oligonucleotides as well as small molecule inhibitors. We have developed a simple, sensitive and robust spectrophotometric assay for quantifying the extent of neoplasia in transgenic larval zebrafish, and have demonstrated that targeted knockdown of MAPK, PI3K and TOR signalling components antagonizes melanoma development. Reversing the logic of this approach implies that this in vivo assay could be used to discover novel antineoplastic compounds, something we would like to demonstrate in the near future.
Lab Members