ABCG2 expression as breast cancer stem cell marker

• Grant number: 14/15418-3
• Support Opportunities: Scholarships abroad - Research
• Start date: June 01, 2015
• End date: May 31, 2016
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Daniel Guimarães Tiezzi
• Grantee: Daniel Guimarães Tiezzi
• Host Investigator: Carlos Caldas
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of Cambridge, England

Abstract

The hierarchical model, defined by the presence of distinct cellular population with particular biological activity, has been proposed in the wake of the identification and isolation of a cell subpopulation with self-renewal and multilineage differentiation potential within hematological and solid malignant tumors. As these functional features were first described in primordial cells, some authors have named this cell subpopulation as cancer stem cells (CSCs). Currently, the CSCs theory has been used to explain mechanism of resistance and recurrence in malignant tumors. According to this theory, CSCs would be responsible for metastatic dissemination, and the patient prognostic would be defined by the CSC quantity and quality within the primary tumor. To identify and to characterize this subpopulation is an alternative to the development of predictive factors of response to chemotherapy, and opens new opportunities to tumor biology comprehension and target therapy development.Although some cellular markers can identify a cell population enriched for CSCs in breast carcinomas, there is not an ideal maker able to identify a specific subpopulation of cells responsible for the resistance to cytotoxic treatment and tumor recurrence. Our preliminary data suggest the expression of ABCG2 protein can identify a cell population with stem cell property in breast cancer. The objective of this study is to analyze the functional properties of ABCG2 positive cell population in a breast cancer xenograft model aiming to understand the molecular mechanisms responsible for cancer stemness and resistance to therapy. (AU)