2014, Number 1
Effect of cryotherapy over the expression of vascular endothelial growth factor and pigment epithelium-derived factor
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ABSTRACTBackground: Cryotherapy is a no invasive technique that uses intense cold to freeze and destroy cancer tissues. There are no descriptions of its effects over the expression of vascular endothelial growth factor and pigment epithelium-derived factor.
Methods: Experimental study in cryogenic spot were applied in the right sclera of twelve pigs for ten minutes. Other 3 pigs were used as normal controls. Animals were sacrificed at 7, 14 and 21 and the tissues of choriodes and retina were dissected in areas of approximately 1 cm2 surrounding cryogenic spots. Expression levels of vascular endothelial growth factor and pigment epithelium-derived factor were determined analyzed using polymerase chain reaction coupled to reverse-transcription.
Results: Vascular endothelial growth factor was significantly downregulated (24%, p ‹ 0.05) seven days post-treatment meanwhile pigment epithelium-derived factor levels increased 44.8% (p ‹ 0.05) as compared to normal controls (untreated). Both vascular endothelial growth factor and pigment epithelium-derived factor levels remain the same until day 14 but returned to basal expression at day 21.
Discussion: This work expose the relation of cryotherapy with the expression of two factors related to angiogenesis. Results showed significant changes on the expression of vascular endothelial growth factor and pigment epithelium-derived factor illustrating that both proteins are regulated in response to cryogenic treatment in relatively short periods (21 days).
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