LINC00205 promotes proliferation,migration and invasion of HCC cells by targeting miR-122-5p

Long non-coding RNAs (lncRNAs) have been identified as crucial regulators in the tumorigenesis and progression of hepatocellular carcinoma (HCC). Recently, long intergenic non-protein coding RNA 205 (LINC00205) has been identified as a prognostic biomarker in HCC. However, the biological role of LINC0205 and its potential molecular mechanism are poorly investigated. Here, we found that the expression of LINC00205 was dramatically up-regulated in HCC tissues compared to adjacent nontumor tissues. Furthermore, the level of LINC00205 in both Hep3B and Huh7 cells was prominently higher than that in normal hepatic cell line LO2. Notably, the high expression of LINC00205 was strongly correlated with tumor size ≥5 cm, venous infiltration and advanced tumor stages. Functionally, LINC00205 knockdown obviously repressed the proliferation, migration and invasion of Hep3B and Huh7 cells in vitro. An inverse correlation between LINC00205 and miR-122-5p was detected in HCC tissues. Interestingly, LINC00205 knockdown increased the level of miR-122-5p in both Hep3B and Huh7 cells. Mechanistically, luciferase reporter assay demonstrated LINC00205 acted as a competing endogenous RNA (ceRNA) by directly interacting with miR-122-5p. More importantly, miR-122-5p overexpression significantly restrained the proliferation, migration and invasion of HCC cells. Collectively, our study provides solid evidence to support the oncogenic role of LINC00205 in HCC, which may be benefit for the improvement of HCC therapy.     

miR-338-3p inhibits the proliferation and migration of gastric cancer cells by targeting ADAM17

Background: MicroRNAs (miRNA) have been documented playing a critical role in cancer progression. Although miR-338-3p has been implicated in several cancers, its role in gastric cancer is still unknown. The aim of our study was to investigate the role of miR-338-3p in gastric cancer progression. Methods: Expression levels of miR-338-3p in gastric cancer cell lines and tissues were determined by quantitative real-time PCR (qRT-PCR). The effect of miR-338-3p on proliferation was evaluated by MTT assay, cell migration and invasion were evaluated by transwell migration and invasion assays. Furthermore, luciferase reporter assay was conducted to confirm the target gene of miR-338-3p, and the results were validated in gastric cancer cells. Results: In the present study, we found that miR-338-3p was down-regulated in both gastric cancer cell lines and tissues. Enforced expression of miR-338-3p inhibited proliferation, migration and invasion of gastric cancer cells in vitro. Moreover, we identified A disintegrin and metalloproteinase 17 (ADAM17) gene as potential target of miR-338-3p. Importantly, ADAM17 rescued the miR-338-3p mediated inhibition of cell proliferation, migration and invasion. Conclusions: Our study suggested that miR-338-3p is significantly decreased in gastric cancer, and inhibits cell proliferation, migration and invasion partially via the downregulation of ADAM17. Thus, miR-338-3p may represent a potential therapeutic target for gastric cancer intervention.     

番泻苷B抑制STAT3和ERK1/2磷酸化对A549细胞生长侵袭及裸鼠成瘤的影响

目的　探讨番泻苷B对A549细胞生长、侵袭及裸鼠成瘤的影响及机制。 方法　采用0、5、10、20 μM番泻苷B处理非小细胞肺癌A549细胞,将细胞随机分为4组进行后续实验,Brdu染色检测各组细胞增殖;Hoechst染色检测细胞凋亡;划痕实验检测细胞迁移;Transwell实验检测细胞侵袭;蛋白免疫印迹检测ki67、PCNA 、cl-caspase-3、cl-caspase-9、VEGF、N-cadherin和E-cadherin蛋白表达水平,STAT3和ERK1/2的磷酸化情况;建立荷瘤小鼠模型,检测肿瘤重量,免疫组化检测Ki67和VEGF表达。 结果　与Control组相比较,各番泻苷B剂量组Brdu阳性细胞数量、侵袭细胞数明显减少（P<0.05）,细胞凋亡率明显上升（P<0.05）,细胞划痕愈合率降低（P<0.05）,ki67、PCNA、VEGF、N-cadherin蛋白水平明显降低（P<0.05）,cl-caspase-3、cl-caspase-9、E-cadherin蛋白水平明显升高（P<0.05）,STAT3和ERK1/2的磷酸化水平均明显降低（P<0.05）,降低荷瘤小鼠肿瘤重量与Ki67和VEGF表达水平（P<0.05）。 结论　番泻苷B抑制STAT3、ERK1/2磷酸化对A549细胞体内外生长有抑制作用。     

Coordinated expression of REG4 and aldehyde dehydrogenase 1 regulating tumourigenic capacity of diffuse‐type gastric carcinoma‐initiating cells is inhibited by TGF‐β

Aldehyde dehydrogenase 1 (ALDH1) has been shown to serve as a marker for cancer‐initiating cells (CICs), but little is known about the regulation of the CIC functions of ALDH1+ cancer cells. We isolated ALDH1+ cells from human diffuse‐type gastric carcinoma cells and characterized these cells using an Aldefluor assay. ALDH1+ cells constituted 5–8% of the human diffuse‐type gastric carcinoma cells, OCUM‐2MLN and HSC‐39; were more tumourigenic than ALDH1? cells; and were able to self‐renew and generate heterogeneous cell populations. Using gene expression microarray analyses, we identified REG4 (regenerating islet‐derived family, member 4) as one of the genes up‐regulated in ALDH1+ cells, and thus as a novel marker for ALDH1+ tumour cells. Induced expression of REG4 enhanced the colony‐forming ability of OCUM‐2MLN cells, while knockdown of REG4 inhibited the tumourigenic potential of ALDH1+ cells. We further found that TGF‐β signalling reduces the expression of ALDH1 and REG4, and the size of the ALDH1+ cell population. In human diffuse‐type gastric carcinoma tissues, the expression of ALDH1 and REG4 correlated with each other, as assessed by immunohistochemistry, and ALDH1 expression correlated inversely with Smad3 phosphorylation as a measure of TGF‐β signalling. These findings illustrate that, in diffuse‐type gastric carcinoma, REG4 is up‐regulated in ALDH1+ CICs, and that the increased tumourigenic ability of ALDH1+ cells depends on REG4. Moreover, TGF‐β down‐regulates ALDH1 and REG4 expression, which correlates with a reduction in CIC population size and tumourigenicity. Targeting REG4 in ALDH1+ CICs may provide a novel strategy in the treatment of diffuse‐type gastric carcinoma. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.