Avaliação do potencial anti-tumoral de um inibidor de gli1 em carcinoma escamocelular oral

Abstract

Introduction. Oral squamous cell carcinoma (OSCC) is a disease that presents a poor prognosis and few therapeutic advances. It´s necessary to uncover the mechanisms involved in its pathogenesis, including the participation of embryonic signaling pathways, such as the Hedgehog (HH) pathway. This cascade is important for tumor initiation and biological behavior, as well as maintenance of the tumor stem cell population, with direct reflexes in drug resistance. Aim. To study the antitumor effects of the X compound on gene expression of HH pathway components, proliferation and death in OSCC cells. Methodology. The OSCC cells (HSC3, CAL27, SCC4, SCC9, SCC15 e SCC25) were cultured in DMEM medium. Initially, cytotoxicity was assessed against different tumor and non-tumor cells by the Alamar Blue assay. Expression of HH pathway components was assessed by qPCR reactions using TaqMan Gene Expression Assays ™ after 12 hours of treatment with the test compounds. Viability, cell cycle and death standard assays in HSC3 cells were performed at different incubation times with the X compound (18 and 36 μM) by flow cytometry. The morphological alterations were evaluated through FSC (size / volume) and SSC (granulosity) parameters, obtained by cytometry. Results. Cytotoxicity analysis of the test compound by Alamar Blue demonstrated greater sensitivity to treatment in HSC3 cell (IC50: 36 μM) in relation to the other cell types tested, and it was chosen to the analysis of the effects of the X compound in OSCC cells. The X compound was able to reduce mRNA levels of the GLI1 transcription factor at the concentration of 36 μM after 12 hours of treatment. The GLI inhibitor significantly reduced the cell viability of HSC3 cells after 24 hours of treatment. Cell cycle and death standard assays demonstrated a significant increase in nuclear fragmentation in the sub-G1 phase and cell death by apoptosis. Conclusion. The GLI inhibitor significantly reduced GLI1 gene expression, indicating reduction of HH pathway downstream activity within 12 hours of treatment. In addition, the test compound significantly reduced viability and promoted a significant increase in nuclear fragmentation and cell death by apoptosis in OSCC cells.