RESUMO
Cancer stem-like cells are rare immortal cells within tumor, which are thought to play important roles in ionizing radiation (IR) therapy-resistance. Quercetin is a natural flavonoid with potential anti-cancer properties without significant cytotoxicity in normal tissues. In this study, we demonstrated that quercetin-IR combination treatment exhibited more dramatic anti-cancer effect than either quercetin or IR treatment alone via targeting colon cancer stem cells (CSCs) and inhibiting the Notch-1 signaling. These effects were further verified by in vivo studies which showed remarkable decrease of the CSCs markers and the expression of Notch-1 signaling proteins in human colon cancer xenografts in nude mice. Co-treatment with quercetin and low dose of radiation significantly reduced the expressions of all five proteins of γ-secretase complex in HT-29 and DLD-1 cells. In addition, ectopic expression of the Notch intracellular domain (NICD) partly reversed the inhibition effects by the combination therapy. In conclusion, our results indicated that the combination of quercetin (20 µM) and IR (5Gy) might be a promising therapeutic strategy for colon cancer treatment by targeting colon cancer stem-like cells and inhibiting the Notch-1 signaling. In future studies, we intend to further explore the potential therapeutic efficacy of the quercetin-radiation combination treatment in clinical trials.
Assuntos
Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/radioterapia , Quercetina/uso terapêutico , Tolerância a Radiação/efeitos dos fármacos , Receptores Notch/metabolismo , Transdução de Sinais , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/efeitos da radiação , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/efeitos da radiação , Quercetina/farmacologia , Tolerância a Radiação/efeitos da radiação , Radiação Ionizante , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Aim: We performed a meta-analysis to explore the efficacy of immunotherapy for patients with squamous non-small-cell lung cancer (NSCLC). Materials & methods: Randomized clinical trials comparing immunotherapy with chemotherapy for advanced NSCLC patients were included. Results: A total of 11 trials (3112 patients) were included. PD-1/PD-L1 inhibitors demonstrated significant superiority to chemotherapy in overall survival (OS) (hazard ratio [HR]: 0.74; p < 0.001) and progression-free survival (PFS) (HR: 0.66; p < 0.001) for squamous NSCLC. The OS and PFS benefits of PD-1/PD-L1 inhibitors for squamous NSCLC were similar in subgroup analyses of line settings, PD-L1 expression and different study methodologies. No advantage in OS was found in advanced squamous NSCLC patients treated with atezolizumab (HR: 0.87; p = 0.087). Conclusion: PD-1/PD-L1 inhibitors significantly improved OS and PFS in advanced squamous NSCLC patients when compared with chemotherapy.