The “cancerized field” concept posits that cells in a given tissue share an oncogenic mutation or insult and are thus cancer-prone, yet only discreet clones within the field initiate tumors. Nearly all benign nevi carry oncogenic BRAFV600E mutations, but they only rarely become melanoma. The zebrafish crestin gene is expressed embryonically in neural crest progenitors (NCP’s) and is specifically re-expressed in melanoma. We show by live imaging of transgenic zebrafish crestin reporters that, within a cancerized field (BRAFV600E-mutant; p53-deficient), a single melanocyte reactivates the NCP state, and this establishes that a fate change occurs at melanoma initiation in this model. We show the crestin element is regulated by NCP transcription factors, including sox10. Forced sox10 overexpression in melanocytes accelerated melanoma formation, consistent with activation of a NCP gene signature and super-enhancers leading to melanoma. Our work highlights the importance of NCP state reemergence as a key event in melanoma initiation.

Mutations in the von Hippel-Lindau (VHL) gene are responsible for VHL disease, congenital polycythemia, and are found in many sporadic tumor types as well. Reports of VHL mutations are dispersed throughout original articles and databases that have not been recently updated. We compiled a comprehensive mutation table of 1,548 germline and somatic VHL mutations, derived from this protein of only 213 amino acids. We describe detailed phenotype and gene mutation information for 945 VHL families, including 30 previously unpublished kindreds from The Netherlands (six novel mutations). These data represent the most extensive catalog of germline VHL mutations to date. We also review VHL disease, known and theorized pathogenesis of common VHL manifestations, and genotype-phenotype correlations. Analysis of all VHL families, excluding germline mutations resulting in congenital polycythemias, describes the spectrum of mutation types: 52% missense, 13% frameshift, 11% nonsense, 6% in-frame deletions/insertions, 11% large/complete deletions, and 7% splice mutations. This easy-to-use compilation of VHL mutations is intended to facilitate research and function as a necessary adjunct for physicians when providing patient information. Hum Mutat 31:521-537,

Metastasis is the defining feature of advanced malignancy, yet remains challenging to study in laboratory environments. Here we describe a high-throughput zebrafish system for comprehensive, in vivo assessment of metastatic biology. First, we generated several stable cell lines from melanomas of transgenic mitfa-BRAFV600E;p53−/− fish. We then transplanted the melanoma cells into the transparent casper strain to enable highly quantitative measurement of the metastatic process at single cell resolution. Using computational image analysis of the resulting metastases, we generated a metastasis score, μ, that can be applied to quantitative comparison of metastatic capacity between experimental conditions. Furthermore, image analysis also provided estimates of the frequency of metastasis-initiating cells (~1/120,000 cells). Finally, we determined that the degree of pigmentation is a key feature defining cells with metastatic capability. The small size and rapid generation of progeny combined with superior imaging tools make zebrafish ideal for unbiased high-throughput investigations of cell-intrinsic or microenvironmental modifiers of metastasis. The approaches described here are readily applicable to other tumor types and thus serve to complement studies also employing murine and human cell culture systems.