ABSTRACT
Macrophages are essential inflammatory cells which regulate the features of immune reactions within tumors. Many studies have reported their regulatory roles in immunity through cytokines and cell signaling. However, relatively few studies have focused on their metabolic features and mechanisms. We aimed to determine the signaling pathway regulating cell metabolism and the mechanism related to the regulation of human tumor-associated macrophages (TAMs) in gastric cancer (GC). Tumor-infiltrated macrophages were isolated from human GC tissues using magnetic beads, gene transcription was determined by real-time PCR, protein expression was monitored using western blots, metabolites were determined using HPLC, and transcriptional regulation was analyzed by the luciferase-based reporter gene system. A significant decrease in microRNA (miR)-30c and an increase in regulated in development and DNA damage responses 1 (REDD1) were detected in human GC TAMs, the transcription of miR-30c was negatively correlated with REDD1. MicroRNA-30c expression was suppressed by hypoxia-inducible factor-1α activation and related to decreased mTOR activity as well as glycolysis in human GC TAMs. Hypoxia-regulated miR-30c downregulated REDD-1 expression by targeting its 3'UTR. Overexpression of miR-30c or restored mTOR activity in macrophages with miR-30cLow expression promoted M1 macrophage differentiation and function in TAMs. Therefore, hypoxia in the human GC microenvironment suppressed the expression of miR-30c, and decreased mTOR activity as well as glycolysis in GC TAMs, thus inhibiting M1 differentiation and function. These results provide a novel metabolic strategy for tumor microenvironment-based therapy.
Subject(s)
Glycolysis/genetics , Hypoxia/genetics , Macrophages/pathology , MicroRNAs/genetics , Stomach Neoplasms/genetics , TOR Serine-Threonine Kinases/genetics , 3' Untranslated Regions/genetics , Cell Differentiation , Cell Line , Cell Proliferation/genetics , Down-Regulation/genetics , Female , Gene Expression Regulation, Neoplastic/genetics , Humans , Hypoxia/pathology , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Male , Middle Aged , Signal Transduction/genetics , Stomach Neoplasms/pathology , Transcription Factors/genetics , Transcription, Genetic/genetics , Tumor Microenvironment/geneticsABSTRACT
Objective To investigate the expression level of antisense non-coding RNA in the INK4 locus (ANRIL) in hepatocellular carcinoma (HCC) tissues and to evaluate its relation to clinicopathological features and prognosis of HCC.Methods Quantitative real-time polymerase chain reaction (qRT-PCR) method was used to detect the expression of ANRIL in HCC tissues and adiacent tissues (n =90) and to analyze its relationship with clinicopathological data.Kaplan-Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome.Small interfering RNA (siRNA) was used to silence ANRIL and to explore the effects of reduced ANRIL expression on cell growth and metastasis.Results ANRIL expression in HCC tissues was significantly higher than in the adjacent non-tumor tissues (t =13.083,P ＜ 0.05).The expression of ANRIL was remarkably associated with the histologic grade (x2 =40.724,P ＜ 0.05) and TNM stage (x2 =43.245,P ＜ 0.05).The mean survival time of the patients with high ANRIL was 18.2 months (95％ CI:14.9-21.5 months),shorter than 39.4 months (95％ CI:35.5-43.4 months) in low expression (x2 =47.590,P ＜0.05).Multivariate analysis suggested that high ANRIL expression was an independent predictor of poor prognosis (HR =2.143,95％ CI:1.083-4.243,P ＜ 0.05).Decreased expression of ANRIL could suppress the cell proliferation,migration and invasion of HCC cells.Conclusion Positive ANRIL expression is negatively correlated with the prognosis of HCC patients.
