RESUMO
Acetylshikonin (AS) is an active component of Lithospermum erythrorhizon Sieb. et Zucc that exhibits activity against various cancers; however, the underlying mechanisms of AS against oesophageal squamous carcinoma (ESCC) need to be elusive. The research explores the anti-cancer role and potential mechanism of AS on ESCC in vitro and in vivo, providing evidences for AS treatment against ESCC. In this study, we firstly demonstrated that AS treatment effectively inhibits cell viability and proliferation of ESCC cells. In addition, AS significantly induces G1/S phage arrest and promotes apoptosis in ESCC cell lines. Further studies reveal that AS induces ER stress, as observed by dose- and time-dependently increased expression of BIP, PDI, PERK, phosphorylation of eIF2α , CHOP and splicing of XBP1. CHOP knockdown or PERK inhibition markedly rescue cell apoptosis induced by AS. Moreover, AS treatment significantly inhibits ESCC xenograft growth in nude mice. Elevated expression of BIP and CHOP is also observed in xenograft tumours. Taken together, AS inhibits proliferation and induces apoptosis through ER stress-activated PERK/eIF2α /CHOP pathway in ESCC, which indicates AS represents a promising candidate for ESCC treatment.
Assuntos
Antraquinonas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Camundongos , Animais , Humanos , eIF-2 Quinase/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismo , Camundongos Nus , Estresse do Retículo Endoplasmático , Apoptose , Fator de Transcrição CHOP/metabolismoRESUMO
Acetylshikonin (ASK) is a natural naphthoquinone derivative of traditional Chinese medicine Lithospermum erythrorhyzon. It has been reported that ASK has bactericidal, anti-inflammatory and antitumour effects. However, whether ASK induces apoptosis and autophagy in acute myeloid leukaemia (AML) cells and the underlying mechanism are still unclear. Here, we explored the roles of apoptosis and autophagy in ASK-induced cell death and the potential molecular mechanisms in human AML HL-60 cells. The results demonstrated that ASK remarkably inhibited the cell proliferation, viability and induced apoptosis in HL-60 cells through the mitochondrial pathway, and ASK promoted cell cycle arrest in the S-phase. In addition, the increased formation of autophagosomes, the turnover from light chain 3B (LC3B) I to LC3B II and decrease of P62 suggested the induction of autophagy by ASK. Furthermore, ASK significantly decreased PI3K, phospho-Akt and p-p70S6K expression, while enhanced phospho-AMP-activated protein kinase (AMPK) and phospho-liver kinase B1(LKB1) expression. The suppression of ASK-induced the conversion from LC3B I to LC3B II caused by the application of inhibitors of AMPK (compound C) demonstrated that ASK-induced autophagy depends on the LKB1/AMPK pathway. These data suggested that the autophagy induced by ASK were dependent on the activation of LKB1/AMPK signalling and suppression of PI3K/Akt/mTOR pathways. The cleavage of the apoptosis-related markers caspase-3 and caspase-9 and the activity of caspase-3 induced by ASK were markedly reduced by inhibitor of AMPK (compound C), an autophagy inhibitor 3-methyladenine (3-MA) and another autophagy inhibitor chloroquine (CQ). Taken together, our data reveal that ASK-induced HL-60 cell apoptosis is dependent on the activation of autophagy via the LKB1/AMPK and PI3K/Akt-regulated mTOR signalling pathways.
Assuntos
Proteínas Quinases Ativadas por AMP , Proteínas Proto-Oncogênicas c-akt , Proteínas Quinases Ativadas por AMP/metabolismo , Antraquinonas , Apoptose , Autofagia , Caspase 3 , Proliferação de Células , Células HL-60 , Humanos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Oesophageal cancer is one of the most frequent solid malignancies and the leading cause of cancer-related death around the world. It is urgent to develop novel therapy strategies to improve patient outcomes. Acetylation modification of histones has been extensively studied in epigenetics. BRD4, a reader of acetylated histone and non-histone proteins, has involved in tumorigenesis. It has emerged as a promising target for cancer therapy. BRD4 inhibitors, such as JQ1, have exerted efficacious anti-proliferation activities in diverse cancers. However, the effects of JQ1 on oesophageal cancer are still not fully described. Here, we demonstrate that JQ1 suppresses cell growth and triggers cellular senescence in KYSE450 cells. Mechanistically, JQ1 up-regulates p21 level and decreases cyclin D1 resulting in G1 cycle arrest. The inhibitory effects of JQ1 on KYSE450 cells are independent on apoptosis. It activates cellular senescence by increasing SA-ß-gal activity. BRD4 knockdown by shRNA recapitulates cellular senescence. We also display that administration of JQ1 decreases recruitment of BRD4 on the promoter of aurora kinases A and B. Inhibitors targeting at AURKA/B phenocopy JQ1 treatment in KYSE450 cells. These results identify a novel action manner of BRD4 in oesophageal cancer, which strengthens JQ1 as a candidate drug in oesophageal cancer chemotherapy.
Assuntos
Aurora Quinase A , Aurora Quinase B , Proteínas de Ciclo Celular/antagonistas & inibidores , Senescência Celular , Neoplasias Esofágicas/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Apoptose , Aurora Quinase A/metabolismo , Aurora Quinase B/metabolismo , Azepinas/farmacologia , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Regulação para Baixo , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Humanos , Proteínas Nucleares/genética , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/metabolismo , Triazóis/farmacologia , Regulação para CimaRESUMO
Doxorubicin (DOX) as a first-line chemotherapeutic drug has been widely used for therapy of human cancers. However, side effects and chemo-resistance severely blocked its clinic application. Herein, natural borneol (NB) as a novel monoterpenoid chemosensitizer was found to have the potential to increase the blood brain barrier (BBB) permeability and intracellular uptake of DOX in vitro, and synergistically enhanced DOX-induced cytotoxicity in human glioma cells. NB treatment significantly potentiated DOX-induced G2/M cell cycle arrest by triggering reactive oxygen species (ROS)-mediated DNA damage. NB also enhanced DOX-induced dysfunction of MAPKs and PI3â¯K/AKT pathways. Furthermore, U251â¯human glioma xenograft growth in vivo was also effectively inhibited by combined treatment of DOX with NB through induction of G2/M-phase arrest and antiangiogenesis. Taken together, our finding validated that NB could act as novel chemosensitizer to enhance DOX-induced anticancer efficacy, and strategy of using NB and DOX could be a high efficient way in therapy of human cancers.