Banca de DEFESA: DAVI SILVA VALE NASCIMENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DAVI SILVA VALE NASCIMENTO
DATE: 04/03/2022
TIME: 09:00
LOCAL: IGM Sala Virtual 5
TITLE:

Therapeutic potential of PICTILISIB and its effects on the pathway HEDGEHOG IN METASTATIC LINEAGE OF 

CARCINOMA ORAL SCAMOCELLULAR

KEY WORDS:

Hedgehog; Pictilisib; PI3K/AKT.

PAGES: 74
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

ABSTRACT Oral squamous cell carcinoma (OSCC) is a serious public health problem with a high prevalence in populations with low socioeconomic status, and is often diagnosed at a late stage, when the prognosis becomes poor. There are still few drug options for the treatment of this tumor in patients. Previously, we demonstrated that the embryonic Hedgehog (HH) pathway is reactivated in this tumor, leading to a more aggressive profile. Thus, the search for drugs that inhibit the HH pathway, either by inhibiting it’s canonical or non-canonical activation, becomes of great relevance for the treatment of OSCC. Among the non-canonical activation mechanisms of the HH pathway, the interaction with PI3K/AKT, an important cell survival pathway, stands out. The aim of this work was to evaluate in vitro antitumor activity and the pharmacological inhibition of components of the HH pathway by a pharmacological PI3K inhibitor, Pictilisib, in a metastatic line of OSCC. Thus, treatment of HSC3 cells with Pictilisib at different concentrations was performed to evaluate cytotoxicity, cell viability, apoptosis analysis by annexin-PI assay in flow cytometry, cell migration analysis by scratch assay, in addition to the evaluation of expression of the components of the HH pathway by Western blot, Immunofluorescence and RT-qPCR. Pictilisib presented a cytotoxicity profile in the HSC3 line, with an IC50 value of 0,05 µM. At concentrations of 0.97 μM and 1.94 μM, a significant reduction in cell viability was demonstrated, in addition to an increase in the percentage of cells in the sub-G1 phase after 48 and 72 h of incubation with Pictilisib at a concentration of 0.97 μM. The Annexin-PI assay demonstrated induction of apoptosis 48 and 72 h after incubation with Pictilisib at concentrations of 0.97 µM and 1.94 µM. The cell migration assay demonstrated that treatment with Pictilisib reduced cell migration at 6 and 24 h. Through the Western blot technique, PTCH1, SHH and GLI1 proteins were analyzed after treatment with Pictilisib in a period of 24h at concentrations of 0.97 and 1.94 µM, but no difference was observed in the expression of these proteins with the treatment . Using the immunofluorescence technique, the proteins GLI1, GLI2 and SMO were analyzed in relation to their presence and location. The results demonstrate strong immunoexpression of the mentioned components, with nuclear labeling of proteins GLI1, GLI2 and SMO at both concentrations with Pictilisib. The gene expression of the components of the Hedgehog pathway (GLI1, GLI2 and GLI3) was evaluated by RT-qPCR in the HSC3 line after 24 h of incubation with 1.94 µM Pictilisib. No inhibition of GLI1 and GLI2 mRNA expression was observed when treated cells were compared with untreated control. However, an increase in GLI3 mRNA was observed after incubation with Pictilisib at 1.94 µM. In conclusion, the data from this study support a potential role of Pictilisib as a promising drug for therapeutic use in OSCC. The role of this drug in the interaction of PI3K/AKT with the HH pathway deserves further investigation in future studies.

BANKING MEMBERS:
Presidente - 019.601.955-90 - BRUNO SOLANO DE FREITAS SOUZA - UFBA
Externa ao Programa - 2981711 - CAROLINE BRANDI SCHLAEPFER SALES
Externo à Instituição - DANIEL PEREIRA BEZERRA