Analysis of RASSF9 function in melanoma in 2D and 3D models

• Grant number: 20/03304-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2021
• End date: September 12, 2023
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: João Gustavo Pessini Amarante Mendes
• Grantee: Ronaldo Rodrigues Ribeiro
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 22/08915-7 - Dissecting Ras-activation of NF-kB-dependent cytokine production, BE.EP.MS

Abstract

Melanoma is the most lethal type of skin cancer. It is caused by the transformation of melanocytes, cells that promote skin pigmentation. Melanoma can be divided into four different groups depending on the genetic modifications. The two with higher incidence show modified sequences of B-Raf and Ras proteins. Ras is one of the most important proteins in solid tumors and its effectors can be good therapeutic targets. The members of RASSF family (Ras-association Family) were characterized by their participation in apoptosis induction mediated by Ras activation. This gene family is subdivided into two subgroups, the first is composed by RASSF1-6 and the other is composed by RASSF7-10. The RASSF1-6 members interact with Ras through the C-terminal portion and are the most studied members, while RASSF7-10 members present the domain RalGDS/AF6 in the N-terminal portion and there is little information about its functions. RASSF9 was first described as P-CIP1, a protein related to vesicle transport. It interacts with Ras and ASPP1/2 during chromosomal segregation. In addition, RASSF9 is crucial for the asymmetric division that induces differentiation of keratinocytes and dermal homeostasis. We developed a non-metastatic murine melanoma strain (Tm1.Luc) deficient for RASSF9 through the CRISPR/Cas9 system. We observed a reduction in the proliferative capacity in vitro and in vivo of cells knockout for this gene that can be explained by the suppression of the Ras/Raf/MERK/ERK pathway. In this project, we intend to expand studies in 2D culture and evaluate the behavior of the modified lineage in a 3D culture model. We will compare the growth between deficient and sufficient strains. Also, we will evaluate the status of the Ras/Raf/MERK/ERK pathway, the response to chemotherapeutic drugs and the cytokines released by the tumors in both strains, before and after treatment with chemotherapy. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

RIBEIRO, Ronaldo Rodrigues. Analysis of RASSF9 function in melanoma in 2D models and 3D. 2023. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) São Paulo.