C. Martins

The effect of blue light exposure in an ocular melanoma animal model

BackgroundUveal melanoma (UM) cell lines, when exposed to blue light in vitro, show a significant increase in proliferation. In order to determine if similar effects could be seen in vivo, we investigated the effect of blue light exposure in a xenograft animal model of UM.MethodsTwenty New Zealand albino rabbits were injected with 1.0 × 106 human UM cells (92.1) in the suprachoroidal space of the right eye. Animals were equally divided into two groups; the experimental group was exposed to blue light, while the control group was protected from blue light exposure. The eyes were enucleated after sacrifice and the proliferation rates of the re-cultured tumor cells were assessed using a Sulforhodamine-B assay. Cells were re-cultured for 1 passage only in order to maintain any in vivo cellular changes. Furthermore, Proliferating Cell Nuclear Antigen (PCNA) protein expression was used to ascertain differences in cellular proliferation between both groups in formalin-fixed, paraffin-embedded eyes (FFPE).ResultsBlue light exposure led to a statistically significant increase in proliferation for cell lines derived from intraocular tumors (p < 0.01). PCNA expression was significantly higher in the FFPE blue light treated group when compared to controls (p = 0.0096).ConclusionThere is an increasing amount of data suggesting that blue light exposure may influence the progression of UM. Our results support this notion and warrant further studies to evaluate the ability of blue light filtering lenses to slow disease progression in UM patients.

Metastatic Dormancy and Metastasis Suppressor Genes

To date it is evident that MSGs can suppress metastasis by inhibiting several different steps in the metastatic cascade. Several of the MSGs can inhibit tumor cell motility and invasion, while others can impinge upon tumor cell arrest and extravasation at the secondary site. In addition, a growing list of MSGs that function by inducing dormancy and regulating the final stage of the metastatic cascade, metastatic colonization has been discovered. The idea of metastatic dormancy has become of significant interest to cancer researchers, encouraged by clinical findings similar to those of breasts cancer studies in which up to 45 % of patients with invasive breast cancer will relapse years or even decades after successful treatment for the primary tumor (Aguirre-Ghiso, Nat Rev Cancer 7:834–846, 2007).

Introduction to Metastasis Suppressor Genes

In the past forty to fifty years, clever scientific insight and innovation has rapidly advanced our understanding of the molecular mechanisms of cancer biology . The discoveries of oncogenes and tumor suppressors and the elucidation of their functions has greatly aided our understanding of the molecular etiology of primary tumors. In the last decade, there has been an explosion in the technology available to scientists to study the genetics of cancer cells at several different levels. It is now possible to study a particular cancer at the whole genome , transcriptome, and proteome levels. This vast increase in available information has led to significant advancements in our understanding of the genetic variations and mutations, which can drive the development of a primary tumor in patients.

Metastasis Suppressor Genes

Below is a list of the most extensively studied MSGs, describing their initial characterization as well as what possible mechanism has been characterized for each .