Banca de QUALIFICAÇÃO: FABIO WILLIAN MARTINS DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : FABIO WILLIAN MARTINS DA SILVA
DATE: 20/06/2024
TIME: 09:30
LOCAL: Plataforma Teams
TITLE:

Search for molecular markers in oral cancer for use in liquid biopsy

KEY WORDS:

Oral cancer, molecular markers, mutations, liquid biopsy, next generation sequencing.

PAGES: 30
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Introduction. Oral cancer is a neoplasm that belongs to the subgroups of head and neck cancers and can arise in the lips, tongue, gums, soft and hard palate. It is considered a major global public health problem, frequently occurring in developing countries. More than 90% of oral cancers are represented by oral squamous cell carcinoma (OSCC). The vast majority of oral cancer cases are diagnosed at advanced stages, being associated with affected regional lymph nodes, metastasis, and a high mortality rate. Considering the late diagnoses and the low survival rate of patients with oral cancer, several studies have been conducted to discover efficient markers using proteins, DNA, RNA, or metabolites, aiming to enable early diagnosis and more accurate monitoring of tumor. Despite these efforts, to date there is no clinically useful biomarker for early detection or to better guide the clinical management of patients with this cancer. Objective. To search for molecular markers associated with oral cancer that can be identified not only in the tumor tissue but also in the blood of these patients, aimed at using it in liquid biopsy, which will allow more accurate tumor monitoring with a less invasive technique. Methods. DNA extraction was performed using the AllPrep DNA/RNA kit, and quantification was carried out using the Qubit® 3.0 Fluorometer with the Qubit® dsDNA HS Assay kit. Libraries were prepared using the Ion AmpliSeq Cancer Hotspot Panel v2 (CHPv2) and the Ion AmpliSeq v2.0 barcode adapters. Preliminary Results. Using the Hotspot panel in 23 oral cancer samples, 2,800 mutations in 50 genes involved in carcinogenesis were analyzed. Among the 50 genes analyzed, 33 were mutated, with some genes showing more than one mutation in a single patient. The TP53, PDGFRA, RET, and FGFR3 genes were mutated in all patients (N=23), with the TP53 gene presenting several mutations and variants, predominantly the missense mutation c.215C>G. The PDGFRA gene predominantly showed the synonymous mutations c.1701A>G and c.2472C>T. The RET gene presented synonymous mutations (c.2307G>T/c.2307G>C/c.2712C>G), and the HMGXB3/CSF1R gene, altered in 91% of the samples, showed the following unknown mutations c.*1841T>A|c.*1841TG>GA|c.*36A>T|c.*36CA>TC. Perspectives. Hereafter, reverse hybridization testing will be carried out using the Hybrispot 12 equipment to detect 35 HPV genotypes, aiming to associate these data with the mutation profile and clinical data of patients. Finally, blood samples from oral cancer patients will be collected aiming to detect the validated mutations. The digital PCR technique will be used to detect mutations in the circulating free DNA extracted from blood samples using the QuantStudioTM 3D Digital PCR System, with specific fluorescence probes for the selected mutations.

COMMITTEE MEMBERS:
Presidente - 2255360 - DORALINA DO AMARAL RABELLO RAMOS
Externa ao Programa - 1466126 - ELIZA CARLA BARROSO DUARTE - nullInterna - 2731816 - JULIANA FORTE MAZZEU DE ARAUJO
Externa ao Programa - 2315081 - NILCE SANTOS DE MELO - null