RESUMO
BACKGROUND/AIM: Epigallocatechin-3-gallate (EGCG) is a major polyphenolic component of green tea. EGCG plays a potential role in radio-sensitizing cancer cells. The combined effect of EGCG and radiation was investigated in a colorectal cancer cell line, focusing on nuclear factor (erythroid-derived 2)-like 2 (Nrf2) autophagy signalling. MATERIALS AND METHODS: HCT-116 cells were treated with 12.5 µM EGCG for different periods of time, 2 Gy radiation, or both. Cell viability was determined with the WST-8 assay. The number of colonies was determined with the colony formation assay. mRNA expression of LC3 and caspase-9 was analyzed with quantitative real-time polymerase chain reaction. RESULTS: Combination treatment with EGCG and radiation significantly decreased the growth of HCT-116 cells. The number of colonies was reduced to 34.2% compared to the control group. Immunofluorescence microscopy images showed that nuclear translocation of Nrf2 was significantly increased when cells were treated with the combination of EGCG and radiation compared to the control and single-treatment groups. Combined treatment with EGCG and radiation significantly induced LC3 and caspase-9 mRNA expression. CONCLUSION: EGCG increased the sensitivity of colorectal cancer cells to radiation by inhibiting cell proliferation and inducing Nrf2 nuclear translocation and autophagy.
Assuntos
Catequina/análogos & derivados , Neoplasias Colorretais/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Radiossensibilizantes/farmacologia , Caspase 9/genética , Catequina/farmacologia , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular , Neoplasias Colorretais/genética , Neoplasias Colorretais/terapia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Células HCT116 , Humanos , Proteínas Associadas aos Microtúbulos/genética , Fator 2 Relacionado a NF-E2/genética , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/efeitos da radiação , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/efeitos da radiaçãoRESUMO
BACKGROUND/AIM: Programmed cell death protein 1 (PD-1)/ programmed cell death ligand 1(PD-L1) axis is associated with immune tolerance via inhibition of T cell activation. The aim of this study was to clarify the significance of PD-1 and PD-L1 expressions and analyze the relationships between PD-1, PD-L1, transforming growth factor-ß (TGF-ß) and Forkhead box P3 (Foxp3) expressions in colorectal cancer (CRC). PATIENTS AND METHODS: A total of 116 patients who underwent curative colectomy for stage II/III CRC were included in the study. PD-1, PD-L1, TGF-ß, and Foxp3 expressions were examined by immunohistochemistry and related to prognostic factors by Kaplan-Meier. RESULTS: PD-1 expression was correlated with PD-L1, TGF-ß, and Foxp3 expressions. Overall survival rates were significantly poorer in the PD-1 and PD-L1-positive groups. Multivariate analysis showed that PD-L1-positive is an independent risk factor. Disease-free survival (DFS) was tended in the PD-L1-positive group. The group with double-positive expression had significantly poorer prognosis. CONCLUSION: PD-1 and PD-L1 expressions were associated with a poor prognosis and correlated with TGF-ß and Foxp3 expressions in patients with CRC.
