Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
Ann Surg Oncol. 2013 Dec;20 Suppl 3:S625-35. doi: 10.1245/s10434-013-3106-3. Epub 2013 Jul 18.
Alpha-fetoprotein (AFP)-secreting hepatocellular carcinomas (HCC) represent a genetically distinct subset of tumors often associated with a worse prognosis. However, the molecular mechanisms that underlie these phenotypic differences remain poorly understood.
HCC tumor samples from 27 patients were profiled using the Affymetrix 133 Plus 2.0 GeneChips. GeneGO Metacore software was used to identify altered biologic pathways. Expression validation was confirmed by RT-PCR. Manipulation of miR-675 by overexpression and antagomir-mediated knockdown was carried out with subsequent evaluation of effects on cell behavior by cell cycle, proliferation, invasion, and growth in soft agar assays.
We identified a strong relationship between primary tumor H19 gene expression and elevated serum AFP. H19 has recently been identified to encode microRNA-675 (miR-675), and we confirmed the relationship in an independent sample of patients. Pathway analyses of the effect of miR-675 overexpression in hepatoma cells revealed a predominant upregulation of cell adhesion and cell cycle initiation pathways. We have demonstrated that miR-675 mediates increases in proliferation and an accumulation of cells with tetraploid DNA content associated with a repression of Rb. We also demonstrated that overexpression of miR-675 alters cellular morphology, reduces invasive potential, and increases anchorage-independent growth capacity. These findings are consistent with a mesenchymal-to-epithelial transition, associated with a reduction in the expression of the key EMT mediator, Twist1.
Expression of the miR-675 in hepatocellular carcinoma links a dramatic upregulation of proliferative and growth capacity with inhibition of motility in HCC cells.
甲胎蛋白（AFP）分泌型肝细胞癌（HCC）是肿瘤中遗传特征显著不同的一个亚型，常与预后不良相关。然而，导致这些表型差异的分子机制仍知之甚少。
采用 Affymetrix 133 Plus 2.0 基因芯片对 27 例 HCC 肿瘤样本进行分析。使用 GeneGO Metacore 软件鉴定改变的生物学通路。通过 RT-PCR 进行表达验证。通过过表达和反义寡核苷酸介导的下调来操纵 miR-675，随后通过细胞周期、增殖、侵袭和软琼脂生长实验评估细胞行为的变化。
我们发现原发性肿瘤 H19 基因表达与血清 AFP 升高之间存在很强的关系。H19 最近被鉴定为编码 microRNA-675（miR-675），我们在独立的患者样本中证实了这种关系。对肝癌细胞中 miR-675 过表达影响的通路分析显示，细胞黏附和细胞周期起始通路明显上调。我们已经证明 miR-675 介导增殖增加和四倍体 DNA 含量细胞的积累，同时抑制 Rb。我们还证明 miR-675 的过表达改变了细胞形态，降低了侵袭潜能，并增加了锚定非依赖性生长能力。这些发现与上皮间充质转化一致，与 EMT 调节因子 Twist1 的表达减少相关。
miR-675 在肝细胞癌中的表达将 HCC 细胞中增殖和生长能力的显著上调与运动性抑制联系起来。
