RESUMO
Autophagy is a form of programmed cell degradation that enables the maintenance of homeostasis in response to extracellular stress stimuli. Autophagy is primarily activated by starvation and mediates the degradation, removal, or recycling of cell cytoplasm, organelles, and intracellular components in eukaryotic cells. Autophagy is also involved in the pathogenesis of human diseases, including several cancers. Human uveal melanoma (UM) is the primary intraocular malignancy in adults and has an extremely poor prognosis; at present there are no effective therapies. Several studies have suggested that autophagy is important in UM. By understanding the mechanisms of activation of autophagy in UM it may be possible to develop biomarkers to provide more definitive disease prognoses and to identify potential drug targets for the development of new therapeutic strategies. This article reviews the current information regarding autophagy in UM that could facilitate biomarker and drug development.
RESUMO
OBJECTIVES: Uveal melanoma (UM) is the most common primary intraocular tumour in adults. UM has a poor overall prognosis and ~50% of patients progress to metastatic disease that has a median survival of 5.2 months. There are currently no proven pharmacological treatments for primary or metastatic UM. Research efforts continue to seek new agents. Many natural compounds have shown promising anti-UM activity in in-vitro and/or in-vivo studies. This review summarises the current findings for natural compounds that may be potentially useful in treating UM. KEY FINDINGS: Literature suggests that natural compounds, such as pristimerin, picropodophyllin, oridonin, zeaxanthin, withaferin and FR-900359, may be promising candidate compounds to treat UM. Most of these compounds have demonstrated satisfactory efficacy in inhibiting in-vitro UM cell growth. SUMMARY: The evidence regarding the anti-UM effects of natural compounds is mainly limited to in-vitro studies; to date, only a small number of these agents have been evaluated in vivo. The molecular mechanisms underpinning the anti-UM properties of these compounds remain largely undefined. Further studies are required to evaluate the in-vivo anticancer activity, appropriate dosage regimen and safety of natural compounds that could be developed for use in UM.