RESUMO
Long noncoding RNAs (lncRNAs) have recently been verified to have significant regulatory functions in many types of human cancers. The lncRNA ANRIL is transcribed from the INK4b-ARF-INK4a gene cluster in the opposite direction. Whether ANRIL can act as an oncogenic molecule in cholangiocarcinoma (CCA) remains unknown. Our data show that ANRIL knockdown greatly inhibited CCA cell proliferation and migration in vitro and in vivo. According to the results of RNA sequencing analysis, ANRIL knockdown dramatically altered target genes associated with the cell cycle, cell proliferation, and apoptosis. By binding to a component of the epigenetic modification complex enhancer of zeste homolog 2 (EZH2), ANRIL could maintain lysine residue 27 of histone 3 (H3K27me3) levels in the promoter of ERBB receptor feedback inhibitor 1 (ERRFI1), which is a tumor suppressor gene in CCA. In this way, ERRFI1 expression was suppressed in CCA cells. These data verified the key role of the epigenetic regulation of ANRIL in CCA oncogenesis and indicate its potential as a target for CCA intervention.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante/genética , Proteínas Supressoras de Tumor/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose/genética , Neoplasias dos Ductos Biliares/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Colangiocarcinoma/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Xenoenxertos , Histonas/metabolismo , Humanos , Masculino , Metilação , Camundongos , Interferência de RNA , RNA Interferente Pequeno/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
OBJECTIVE: To investigate the clinical value of the expression of glucose regulated protein 78 (GRP78) for assessment of severity, chemoresistance and prognosis in patients with gastric adenocarcinoma ( GC) . METHODS: A cohort of 237 patients with gastric cancer was included in this study. 160 patients of them were treated by D2 radical gastrectomy and adjuvant chemotherapy. The GRP78 expression was detected by immunohistochemistry and 80 patients of them were tested in vitro for cancer chemosensitivity by ATP-tumor chemosensitivity assay (ATP-TCA). In addition, the relationships were analyzed between GRP78 and age, gender, tumor differentiation, invasion, disease stage, lymph node metastasis and chemoresistance as well as disease-free survival (DFS). RESULTS: The positive rate of GRP78 expression in the gastric adenocarcinoma was 68.8% before the initiation of chemotherapy. The positive GRP78 expression was significantly correlated with tumor invasion depth, poor differentiation, TNM stages, and lymph node metastasis (all P < 0.05), not correlated with gender and age, and high GRP78 expression was associated with the chemoresistance of the gastric cancer cells to chemotherapeutic agents. Negative GRP78 expression was associated with higher sensitivity to both drugs and regimens. The DFS of GRP78-positive group and GRP78-negative group was (53.6 ± 0.9) months and (38.3 ± 0.8) months, respectively (P = 0.041). Interestingly, subgroup analysis revealed that the DFS in GRP78-negative and-positive patients treated with taxane-containing chemotherapy was (58.6 ± 2.6) months and (49.1 ± 2.7) months, respectively, but the difference was statistically not significant (P = 0.111). In contrast, in the subset of GRP78-negative and- positive patients treated with taxane-containing regimens, the DFS was (45.5 ± 1.9) months and (35.1 ± 2.2) months, respectively, showing a significant difference (P = 0.038). In the group of patients with positive GRP78 expression, the patients treated with taxane-containing chemotherapy had a longer DFS [(49.1 ± 2.7) months] than those without that treatment [(35.1 ± 2.2) months], showing a significant difference (P = 0.017). Univariate analysis revealed that DFS was correlated with histological grade, GRP78 expression and lymph node metastasis (all P < 0.05). Multivariate analysis showed that GRP78 expression and TNM staging were independent influencing factors for gastric cancer (both P < 0.05). CONCLUSIONS: The results of our study suggest that GRP78 may be a novel biomarker for assessment of malignant degree and prediction of chemoresistance in gastric cancer, and may be helpful to chemotherapy planning and prognosis prediction in patients with gastric cancer.
Assuntos
Adenocarcinoma/metabolismo , Proteínas de Choque Térmico/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/metabolismo , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Quimioterapia Adjuvante , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Chaperona BiP do Retículo Endoplasmático , Feminino , Gastrectomia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Invasividade Neoplásica , Estadiamento de Neoplasias , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Taxoides/administração & dosagemRESUMO
Accumulating evidence has unfolded the significance of extracellular vesicles (EVs) in diseases and cancers. Here, we attempted to discuss the role of cancer-associated fibroblasts (CAFs)-derived EVs containing miR-199a-5p in gastric tumorigenesis. Upregulated miR-199a-5p was first identified in cancer cells. Then, we selected CAFs for isolation of EVs which were co-cultured with AGS cells. We observed successful delivery of miR-199a-5p via CAF-derived EVs. Besides, miR-199a-5p promoted malignant properties of AGS cells. Moreover, miR-199a-5p downregulated FKBP5, leading to upregulated phosphorylation level of AKT1, which promoted the malignant phenotypes of AGS cells by activating mammalian target of rapamycin complex 1(mTORC1). Exosomal miR-199a-5p from CAFs promoted gastric tumorigenesis in vivo. Our findings point toward the critical role of CAFs-derived EVs carrying miR-199a-5p in gastric cancer progression.