Functional characterization of regulatory proteins involved in DNA repair

• Grant number: 15/06458-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2015
• End date: September 30, 2019
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Jörg Kobarg
• Grantee: Talita Diniz Melo Hanchuk
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 17/03489-1 - From functional studies to searching for new inhibitors for cancer: exploring kinases that regulate the cell cycle of the human NEK family, AP.TEM

Abstract

During the cell cycle the genetic material is under constant endogenous or exogenous attack that induce DNA damage. To protect these lesions, cells have different responses that lead to removal by DNA repair or damage tolerance, so that the genetic material can be replicated despite the damage. The importance of these mechanisms is attested not only by the high level of evolutionary conservation but also by the existence of genetic problems related to defects in these repair mechanisms that result in carcinogenesis, developmental abnormalities and neurodegeneration. The group coordinated by Dr. Jörg Kobarg have been very active in the study of proteins related to cancer, especially Ki-1/57 and the Nek family proteins. Through protein-protein interaction analysis, several important roles are being attributed to these proteins, highlighting the role of Neks during the cell cycle, in cilia formation and the repair of DNA damage pathways. Among the family members of Neks, Nek5 is the most neglected kinase. We recently demonstrated its involvement in cell death process by defects in the mitochondrial respiratory chain and formation of reactive oxygen species. Additionally this protein has a role in homology repair pathway (article in preparation attached). Thus, an important part of this project is the characterization of Nek5 mechanism of action in different pathways of DNA damage repair and its relationship with tumor phenotype.The human protein Ki-1/57 was identified by monoclonal antibody Ki-1, which specifically detected malignant cells of Hodgkin and Reed-Sternberg cells in Hodgkin lymphoma. This protein is expressed in many cancers and yeast two-hybrid screening performed by our group demonstrated its interaction with proteins involved in different pathways of DNA damage repair, suggesting a potential effect of this protein in maintaining DNA integrity. These studies should be complemented by this project, with the exploration of the mechanisms involved and its potential role in DNA repair pathways through the analysis of Ki-1/57 knockout or Nek5 stably silenced cells , in addition to cells stably expressing these wild proteins.Also in this project, we intend to study how human cells respond to chemotherapeutic agents for cancer, to understand the mechanisms involved in the repair of lesions induced by these substances and in search for therapeutic alternatives that could enhance the battle against tumor cells. The development of this project will contribute to the understanding of the mechanisms involved, and consequently, potential targets for therapeutic cancer treatment, which justifies its proposition. In addition to scientific advances, this project will consolidate a partnership, which began with researchers Dr. Lúcio Holanda G. de Freitas Júnior, from Biosciences National Laboratory, Dr. José Vassallo and Dra. Carmen Silvia Passos Lima, both of the Faculty of Medical Sciences of UNICAMP. (AU)

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)

MELO-HANCHUK, TALITA DINIZ; SLEPICKA, PRISCILA FERREIRA; PELEGRINI, ALESSANDRA LUIZA; MARTINS MENCK, CARLOS FREDERICO; KOBARG, JORG. NEK5 interacts with topoisomerase II beta and is involved in the DNA damage response induced by etoposide. Journal of Cellular Biochemistry, v. 120, n. 10, p. 16853-16866, OCT 2019. (14/15982-6, 17/03489-1, 10/51730-0, 15/06458-4, 10/16831-0, 10/15262-2)

MELO-HANCHUK, TALITA DINIZ; MARTINS, MARIANA BONJIORNO; CUNHA, LUCAS LEITE; SOARES, FERNANDO AUGUSTO; WARD, LAURA STERIAN; VASSALLO, JOSE; KOBARG, JORG. Expression of the NEK family in normal and cancer tissue: an immunohistochemical study. BMC CANCER, v. 20, n. 1, JAN 6 2020. (15/06458-4, 17/03489-1, 16/02040-8)