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Toll-like receptor 4 among the plasmatic membrane Toll like receptors plays a role in astrocytoma malignancy

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Author(s):
Isabele Fattori Moretti
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
Defense date:
Examining board members:
Suely Kazue Nagahashi Marie; Erico Tosoni Costa; Maria Lucia Cardillo Correa Giannella; Wellingson Silva Paiva
Advisor: Suely Kazue Nagahashi Marie
Abstract

Toll-like receptors (TLRs) are the first to identify disturbances in the immune system, recognizing pathogens such as bacteria, fungi, and viruses. Since the inflammation process plays an important role in several diseases, TLRs have been considered potential therapeutic targets, including treatment for cancer. However, TLRs\' role in cancer remains ambiguous. This study aims to analyze the expression levels of plasmatic cell membrane TLRs (TLR1, TLR2, TLR4, TLR5, and TLR6) in different grades (II-IV) of human astrocytoma, the most prevalent tumor of CNS. We demonstrated that TLR expressions were higher in astrocytoma samples compared to non-neoplastic brain tissue, by qRT-PCR. The genes and proteins expressions were observed in U87MG and A172 GBM cell lines, proving their presence in the tumor cells. Associated expressions between the known heterodimers TLR1-TLR2 were found in diffusely infiltrative astrocytoma. In GBM, the mesenchymal subtype showed higher levels of TLR expressions in relation to classical and proneural subtypes. Aiming to indentify the role of TLRs in tumor cells, we chose the highest TLR expressed in GBM cells, the TLR4, and performed functional assays stimulating U87MG-GBM cell line with LPS, a natural agonist for TLR4. The proliferation rate was similar in treated and non-treated cell with LPS. However, NF-kB activation was detected after 12hrs of LPS stimulation. When TLR4 signaling pathway was inhibited by a chemical compound (VGX-1027) a decrease in the proliferation rate was observed. Additionally, in silico analysis revealed a strong association of TLRs upregulation with increased expression level of genes related to cell cycle, inflammasome and ripoptosome pathways, further highlighting TLRs as interesting targets for cancer complementary treatment (AU)

FAPESP's process: 16/14695-9 - Toll Like Receptor 4 role in glioblastoma cell lineages
Grantee:Isabele Fattori Moretti
Support Opportunities: Scholarships in Brazil - Master