Banca de QUALIFICAÇÃO: FRANCIELE SCHLEMMER

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : FRANCIELE SCHLEMMER
DATE: 28/08/2024
TIME: 14:30
LOCAL: a designar.
TITLE:

Expression of microRNAs and PARP1 in Breast Cancer Cell Lines and their Potential Predictive Value for Neoadjuvant Chemotherapy Response

KEY WORDS:

Triple-negative Breast Cancer (TNBC), microRNAs, Biomarkers, Pathological Complete Response, Paclitaxel, PARP1

PAGES: 100
BIG AREA: Outra
AREA: Defesa
SUMMARY:

Breast cancer is a complex and heterogeneous disease, with similar tumors presenting diverse prognoses and therapeutic responses. The triple-negative subtype (Triple-negative breast cancer - TNBC) represents about 15% of cases, with chemotherapy using taxanes, anthracyclines, and/or alkylating agents as the primary treatment option. The evaluation of Complete Pathological Response (pCR) is performed through the Residual Cancer Burden (RCB) after neoadjuvant chemotherapy, but only one-third of TNBC patients achieve pCR, indicating a favorable long-term prognosis. DNA repair mechanisms play a crucial role in maintaining genomic integrity, and the dysfunction of these mechanisms is closely linked to carcinogenesis. The assessment of mutations in genes involved in DNA repair pathways has been used as a marker for the administration of new chemotherapeutics, such as PARP (Poly ADP-Ribose Polymerase) inhibitors. MicroRNAs also show potential as biomarkers for diagnosis and prognosis, as they regulate gene expression through the RNA interference (RNAi) process, acting on both oncogenic and tumor suppressor pathways. This study evaluated the expression of microRNAs and DNA repair genes in breast cancer cell lines and FFPE (Formalin-Fixed Paraffin-Embedded) tumor samples from patients diagnosed with TNBC. The cell lines analyzed were MCF-7 (Hormone Receptor Positive, HR+), MDA-MB231 (TNBC, BRCA1 competent), and MDA-MB-436 (TNBC, BRCA1 mutated). We observed significant differences in the expression profiles of miR-7, miR-21, miR-671, and miR-146a among the cell lines, changes in response to Paclitaxel, and in PARP1 expression, correlated with the profile of these microRNAs. In the biopsies, we identified miR-7, miR21, and miR-146a with potential predictive value for pCR in TNBC patients.

COMMITTEE MEMBERS:
Externa à Instituição - PAULA FONTES ASPRINO - SÍRIO
Interna - 1278451 - ELIETE NEVES DA SILVA GUERRA
Interna - 2528668 - PAULA ELAINE DINIZ DOS REIS
Presidente - 1127261 - RICARDO TITZE DE ALMEIDA