|Support type:||Scholarships in Brazil - Master|
|Effective date (Start):||December 01, 2015|
|Effective date (End):||September 30, 2017|
|Field of knowledge:||Health Sciences - Medicine|
|Principal Investigator:||Vanessa da Silva Silveira|
|Grantee:||Mariana Tannús Ruckert|
|Home Institution:||Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil|
In the last few years acute lymphoblastic leukemia (ALL) patients prognosis have been significantly improved, however, some subgroups, such as Ph positive leukemia frequently experience relapse and low cure rates, representing a challenge. The Ph positive leukemias show the BCR-ABL fusion gene, that arises from a translocation between chromosomes 9 and 22. This mutation gives rise to the tyrosine-kinase BCR-ABL, responsible for the hyperactivation of RAS pathway which, among other functions, regulates the oxidative stress levels that are necessary for neoplastic cells' survival. Results previously obtained by Silveira et al. (2013) have shown surprising and interesting data that suggests an association between hyperactivation of RAS pathway and a favorable treatment outcome, pointing to a new research approach. Besides this one, other reports have also shown signs that the hyperactivation of RAS pathway may be related to the increase of cell death. Even though the current approach for Ph positive leukemia's treatment is the use of tyrosine-kinase inhibitors, a lot of patients develop complex resistance mechanisms and relapse. Considering the aforementioned information, this project suggests that constitutive hyperactivation of RAS pathway (promoted by the activity of tyrosine-kinase BCR-ABL), increased by the loss of negative feedback mechanisms can lead to a metabolic imbalance and expose tumor cells to a state of oxidative stress that is higher than the tolerated threshold, thus being highly toxic. In this case, the level of toxicity to which the cell is exposed can sensitize it to chemotherapy. The elucidation of these mechanisms is of great importance and can enable the discovery of new therapeutic targets, providing alternative strategies to the treatment of high risk patients and those that develop resistance to chemotherapy.