Metastatic melanoma is a devastating type of cancer. We have studied melanoma using a zebrafish model in which melanocytes can be transformed through the melanocyte-specific expression of human BRAFV600E in a p53 mutant. With zebrafish genetic and chemical biology tools we hope to reveal critical pathways that participate in the initiation and spreading of melanoma. We have observed the onset of melanoma using a neural crest specific transgenic reporter. crestin, a neural crest progenitor gene, is expressed early in neural crest development and shuts off by day 5 of development. When a melanoma arises, crestin expression reactivates. Using an EGFP reporter, we witnessed single cells transform into melanoma. We plan to search for transcription factors and small molecules that activate the crestin-EGFP transgene. By studying how cancer initiates, we hope to define methods to inactivate these pathways and perhaps halt cancer at its earliest stages. We also have developed a system to rapidly study different subtypes of melanoma. The new method uses a tissue-specific CRISPR technology in F0 fish, which allows rapid modeling of diseases and genotypes relevant to humans. Using this system, we have generated melanomas in vivo by combining BRAFV600E expression with PTEN, P53, or CDKN2A deficiency. We propose to evaluate genes that are deleted in human melanoma, attempting to define their contribution to tumor formation. In particular, we will evaluate two genes (pvrl1 and cdk13) whose loss of function demonstrated melanoma acceleration. We will investigate the role of PVRL1 in cancer cell adhesion and metastasis formation. We plan to further understand the mechanism of CDK13 activity by studying chromatin immunoprecipitation, RNA-Seq, and chromatin accessibility using ATAC-Seq. Our studies will further develop a facile system to study melanoma and have impact on the understanding of cancer initiation and progression. This may lead to the identification of small molecules or drug targets yielding new therapies for metastatic melanoma.
Project Description Melanoma is a cancer of pigmented melanocytes, and we found that the initiating event of melanoma involves reactivation of a neural crest embryonic program. We also have developed the most rapid method available to model different human melanoma genotypes using the zebrafish as a model. This method will allow us to study many melanoma subtypes, understand the mechanism of disease and to identify patient-specific therapies.
Showing the most recent 10 out of 43 publications
