Analysis of the Oncogenic Mechanisms of RMEL3 lncRNA

• Grant number: 24/20203-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2025
• End date: October 31, 2026
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: Enilza Maria Espreafico
• Grantee: Marcos Benedito Adão
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

RMEL3 (Restricted to Melanoma 3) is a lncRNA enriched in melanoma, especially in association with the BRAFV600E mutation and the invasive phenotype. RNA-protein interaction data obtained in our laboratory support the hypothesis of a role for lncRMEL3 as a positive regulator of BRAFV600E and a negative regulator of the Hippo tumor suppressor pathway. In a global gene expression analysis by RNAseq, seeking to identify a gene signature regulated by lncRMEL3 in the serum response, we identified a predominance of tumor suppressor genes, genes related to invasion and metastasis, and cohesive sets of genes involved in the regulation of the innate and adaptive immune response. The data suggest a role for lncRMEL3 in the regulation of the tumor microenvironment and melanoma immune evasion. Given the evolutionary conservation of signaling pathways involved in metastatic progression and therapeutic resistance of melanoma, including innate immune response pathways, and considering new ongoing analyses that indicate a phylogenetic conservation for RMEL3 greater than previously predicted, we propose, in the present project, to explore the molecular mechanisms of RMEL3 in genetically induced cancer in the model organism Drosophila melanogaster. In order to generate transgenic D. melanogaster lines carrying human RMEL3 cDNAs, we selected three isoforms of the gene (RMEL3_1, RMEL3_4 and RMEL3_1A), which will be cloned into the pUAST-attB expression vector for targeted integration into the genome. The plasmid constructs will be microinjected into dechorionated embryos to generate transgenic animals. After physical mapping of the transgenes in the genome, the animals will be crossed with strains carrying the GAL4 driver system to induce the expression of UAS-transgenes or FLP/FRT flip-out to generate tissue mosaics, allowing phenotypic studies and modulation of genetically induced tumorigenesis. The role of RMEL3 isoforms will be explored in relation to the modulation of hyperplastic growth, invasive and metastatic tumor progression, inflammatory tumor microenvironment and systemic innate immune response.