Expression analysis of genes regulated by protein Dermicidina in malignant melanoma cells G-361 by DNA microarray

Abstract

The protein dermicidina (DCD) is encoded by a gene localized in chromosome 12q13.1 portion 12, present only in primates and humans. The protein is secreted by exocrine cells of the skin melanocytes, neurons and epithelial cells of normal breast. Some studies have shown the importance of protein in oncogenic processes in DCD with breast, prostate and melanoma, revealed by its role as a growth factor and cell survival. In studies performed in our laboratory showed that the DCD is expressed in normal skin cells, placenta, brain and in various tumors, including breast carcinomas and malignant melanoma. Biological and biochemical tests showed that the "knockdown" in the expression of DCD in malignant melanoma via G-361 RNA interference (RNAi) significantly decreased the growth in vitro in cell culture and tumor formation in nude mice. Similar results were obtained when nude mice transplanted with cells of G-361 melanoma were treated with rabbit polyclonal antibodies against the protein DCD, administered once a week for 5 weeks. In the present project aims to identify genes differentially expressed in cells of malignant melanoma G-361 control and RNAi cells expressing DCD to analyzing the global gene expression by DNA microarray technology (Human GeneChip 1.0 ST array). Genes differentially expressed (> 3-fold) between the control and expressing RNAi will be validated by testing expression by real-time PCR, immunohistochemistry, Western blot and indirect immunofluorescence. We also intend to make assessments of functional intracellular signaling pathways of proliferation and resistance to cell death. It is expected from these studies show that the protein acts as an oncogene DCD promoting the transcription of genes involved in transformation of normal melanocytes and progression to malignant melanocytes.