Advanced search
Start date
Betweenand

Dnmt1 gene Transcriptional Regulation by Oxidative Stress Caused by Anchorage Blockade Assays in melanocytes

Grant number: 11/09676-1
Support type:Scholarships in Brazil - Doctorate
Effective date (Start): August 01, 2011
Effective date (End): February 28, 2015
Field of knowledge:Biological Sciences - Genetics
Principal Investigator:Miriam Galvonas Jasiulionis
Grantee:Camila Tainah da Silva
Home Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
Associated research grant:06/61293-1 - DNA methylation contribution to carcinogenesis, AP.JP

Abstract

Melanoma represents only 4% of skin cancer types but it has high rates of mortality, especially in advanced cases where there are not effective treatments. Like other cancer types, genetic predisposition, exposure to environmental factors and epigenetic changes can contribute to melanoma development. DNA methylation is one of the most important eukaryotic epigenetic mechanisms and in normal cells promotes silencing of expression of certain genes and maintaining genome stability. Changes in these patterns can lead to cancer cells formation. DNA methyltransferases (Dnmts) are a group of enzymes that act in this process. Different melanoma cell lines were established by our group after submitting a immortalized murine melanocyte cell line (melan-a) to cycles of anchorage blockade. Our group has already showed increased global DNA methylation as well increased dnmt1 (DNA methyltransfase 1) protein levels few hours after melan-a anchorage blockade. Additionally, this increase seems to be related with the high amounts of superoxide anion (O2-) produced during this process. Moreover, we showed that treating melan-a cells during anchorage blockade with Ras inhibitor (FTI) or Erk inhibitor (UO126) abrogates superoxide anion increase, DNA global hypermethylation and Dnmt1 overexpression obeserved. RAS/MEK/ERK signaling pathway seems to be regulated by and regulates superoxide anion production and its activation could be responsible for the high dnmt1 protein level and changes in global DNA methylation during the loss of cell adhesion. Therefore, this work's aim is to uncover the ways in which the O2- modulates dnmt1 gene transcription during the lockout condition anchor. For this, we are going to verify which transcription factors interact with Dnmt1 gene and if they are essential for the transcriptional activity of its promoter. We will also check which pathways are inhibited after O2- depletion or Ras inhibition. This study is very relevant once could elucidate the molecular mechanisms involved in the early stages of melanoma progression. Additionally, may provide a useful data to new drugs development, which could act directly in this pathway.

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
MOLOGNONI, FERNANDA; MACHADO DE MELO, FABIANA HENRIQUES; DA SILVA, CAMILA TAINAH; JASIULIONIS, MIRIAM GALVONAS. Ras and Rac1, Frequently Mutated in Melanomas, Are Activated by Superoxide Anion, Modulate Dnmt1 Level and Are Causally Related to Melanocyte Malignant Transformation. PLoS One, v. 8, n. 12 DEC 16 2013. Web of Science Citations: 15.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.