PRDX1 Influences The Occurrence and Progression of Liver Cancer by Inhibiting Mitochondrial Apoptosis Pathway.

OBJECTIVE: The aim of this study is to elucidate the role of PRDX1 in hepatocellular carcinoma using hepatoma cells. MATERIALS AND METHODS: In this experimental study, we elucidated role of PRDX1, using hepatoma cell lines. RESULTS: PRDX1 was upregulated in different types of cancers, including lung adenocarcinoma, breast cancer and liver cancer reported by several studies. nevertheless, mechanism of inducing liver cell death by PRDX1 remains largely unknown. Here, we showed that PRDX1 expression is enhanced in different cell lines. Here, we used western blot, quantitative real time polymerase chain reaction (qRT-PCR) and different biochemical assays to explore the role of PRDX1. We observed that overexpression of PRDX1 significantly enhanced proliferation of hepatoma cell lines, while knock-down of this gene showed significant inhibitory effects. We found that knock-down of PRDX1 activated cleaved caspase-3, caspase-9 proteins and Poly [ADP-ribose] polymerase 1 (PARP-1), which further executed apoptotic process, leading to cell death. We found that PRDX1 knock-down significantly produced mitochondrial fragmentation. We showed that silencing PRDX1 led to the loss of B-cell lymphoma 2 (Bcl-2) and activated Bcl-2-like protein 11 (Bim) which further induced Bax activation. Bax further released cytochrome c from mitochondria and induced apoptotic proteins, suggesting a significant role of PRDX1 knock-down in apoptosis. Finally, we showed that knock-down of PRDX1 significantly activated expression of Dynein-related protein 1 (Drp1), fission 1 (Fis1) and dynamin-2 (Dyn2) suggesting a crucial role of PRDX1 in mitochondrial fragmentation and apoptosis conditions. This study highlighted an important role of PRDX1 in regulating proliferation of hepatoma cells and thus future studies are required to validate its effect on hepatcoytes. CONCLUSION: We propose that future works on PRDX1 inhibitors may act as a therapeutic candidate for treatment of liver cancer.

MicroRNA­122 regulation of the morphology and cytoarchitecture of hepatoma carcinoma cells.

MicroRNAs (miRNAs) are a large family of post­transcriptional regulators of gene expression that control a number of developmental and cellular processes in eukaryotic organisms and are ~23 nucleotides in length. miRNA­122 is an abundant liver­specific miRNA, implicated in fatty acid and cholesterol metabolism, as well as in hepatitis C viral replication and is frequently suppressed in primary hepatocellular carcinomas. In the current study, the Hep3B cell line with stable overexpression of miR­122 was successfully established through gene transfection methods and drug screening. miR­122 was observed to alter cell morphology in vitro by stable overexpression in Hep3B cells. This alteration was viewed by light microscopy and transmission electron microscopy. These alterations included increases in the cell volume, the appearance of lipid granules and vacuoles, thickening of nuclear membrane, swelling of the mitochondria, cytoplasm vacuolization and a more prominent nucleolus. Furthermore, the study provided novel evidence that miR­122 function was dependent upon its expression level. In addition, it was observed to negatively regulate mitochondria.

Effect of OSW-1 on microRNA expression profiles of hepatoma cells and functions of novel microRNAs.

3ß,16ß,17α-trihydroxycholest-5-en-22-one 16-O-(2-O-4-methoxybenzoyl-ß-D-xylopyranosyl)-(1→3)- (2-O-acet​yl-α-L-arabinopyranoside) (OSW-1) is a member of the cholestane saponin family, which was first isolated from the bulbs of Ornithogalum saundersiae and previously reported to be cytotoxic against several types of malignant cells. However, its antitumor mechanism remains unclear. Therefore, we investigated microRNA (miRNA) expression profiles in order to explore the antitumor activities of OSW-1. Furthermore, following study of differentially expressed miRNAs, the function of novel miRNAs and OSW-1 was determined using known miRNAs and anticarcinogens. The present study demonstrated that treatment with OSW-1 leads to the upregulation and downregulation of a large set of tumor-related miRNAs, including miR-299, miR-1908, miR-125b, miR-187a, miR-1275, hav1-miR-H6-3p, miR-181, miR-210, miR-483, miR-126, miR-208 and others. Notably, miR-141, miR-142, miR-200C and miR-1275 were found to be upregulated by OSW-1 and doxorubicine, as compared with doxorubicine alone. Additionally, the expression fold-change of miR-142-3P was ~58 times higher than its expression with a different treatment. These miRNAs are linked to cancer, including proliferation, differentiation, apoptosis, cell adhesion, migration, polarity and epithelial to mesenchymal transition (EMT).