Clinicopathological parameters of patients with hepatocellular carcinoma (HCC) (n = 34).

<p>HBV, hepatitis B virus; HCV, hepatitis C virus; AFP, alpha-fetoprotein; DCP, des-carboxyprothrombin; PT, prothrombin time.</p

PKR upregulates c-Fos and c-Jun mRNA and protein in the HCC cell lines with HCV infection, JFH1 and H77s.

<p>Cells were transfected with either control or PKR siRNA, and with either control or PKR-expression plasmid (pPKR). c-Fos mRNA was decreased by PKR knockdown (A), and c-Fos was upregulated by PKR overexpression (B). c-Jun mRNA was downregulated by PKR siRNA (C), and upregulated by pPKR (D). Mean ± SEM of six replicates. *p<0.05. n.s.: not significant. Protein expression of c-Fos, c-Jun, JNK1, Erk and their phosphorylated forms determined by Western blotting. Bothc-Fos and c-Jun signaling pathways were activated by PKR (E). DNA binding activities of c-Jun and c-Fos were downregulated by PKR knockdown (F). Mean ± SEM of six replicates. *p<0.05.</p

Model of the role of PKR in cell proliferation and relationships between PKR and other molecules associated with the c-Jun and c-Fos pathways.

<p>SP600125: inhibitor of c-Jun pathway. U0126: inhibitor of c-Fos pathway.</p

Usefulness of a New Three-Dimensional Simulator System for Radiofrequency Ablation

<div><p>Multipuncture radiofrequency ablation is expected to produce a large ablated area and reduce intrahepatic recurrence of hepatocellular carcinoma; however, it requires considerable skill. This study evaluated the utility of a new simulator system for multipuncture radiofrequency ablation. To understand positioning of multipuncture electrodes on three-dimensional images, we developed a new technology by expanding real-time virtual ultrasonography. We performed 21 experimental punctures in phantoms. Electrode insertion directions and positions were confirmed on computed tomography, and accuracy and utility of the simulator system were evaluated by measuring angles and intersections for each electrode. Moreover, to appropriately assess placement of the three electrodes, puncture procedures with or without the simulator were performed by experts and non-experts. Technical success was defined as maximum angle and distance ratio, as calculated by maximum and minimum distances between electrodes. In punctures using 2 electrodes, correlations between angles on each imaging modality were strong (ultrasound vs. simulator: r = 0.991, p<0.001, simulator vs. computed tomography: r = 0.991, p<0.001, ultrasound vs. computed tomography: r = 0.999, p<0.001). Correlations between distances in each imaging modality were also strong (ultrasound vs. simulator: r = 0.993, p<0.001; simulator vs. computed tomography: r = 0.994, p<0.001; ultrasound vs. computed tomography: r = 0.994, p<0.001). In cases with 3 electrodes, distances between each electrode correlated strongly (yellow-labeled vs. red-labeled: r = 0.980, p<0.001; red-labeled vs. blue-labeled: r = 0.953, p<0.001; yellow-labeled vs. blue-labeled: r = 0.953, p<0.001). Both angle and distance ratio (expert with simulator vs. without simulator; p = 0.03, p = 0.02) were significantly smaller in procedures performed by experts using the simulator system. The new simulator system appears to accurately guide electrode positioning. This simulator system could allow multipuncture radiofrequency ablation to be performed more effectively and comfortably.</p></div

The PKR upregulates IL-8 expression and secretion.

<p>IL8 mRNA levels were downregulated by PKR knockdown (A). Supernatants of cultured cells were collected, and IL-8 levels were determined by ELISA. Secreted IL-8 was downregulated by PKR knock-down (B). Assays using the IL-8 promoter-luciferase reporter plasmid: IL-8 promoter activities were downregulated by PKR knockdown (C). Mean ± SEM of six replicates. *p<0.05.</p

c-Jun and c-Fos were activated by the expression of PKR in human HCC tissues with HCV infection.

<p>RNA from HCC specimens of 34 patients, 17 HCC specimens with HCV infection (HCC positive HCC), and 17 HCC without HCV infection (HCC negative HCC). Each group was divided into two subsections by the median PKR mRNA values: Low PKR and High PKR. c-Jun mRNA (A) and c-Fos mRNA (B) were measured. c-Fos mRNA significantly correlated with c-Jun mRNA (r = 0.816, P<0.001) (C). The four human HCC specimens having the highest (High PKR) and the four having the lowest (Low PKR) PKR protein expression were analyzed by Western blotting. c-Jun and c-Fos in the High PKR group were activated more than in the Low PKR group (D).</p

PKR expression was associated with proliferation of JFH1 and H77s cells, which was dependent on both c-Fos and c-Jun signaling pathways.

<p>Wound healing assay: Confluent monolayers of JFH1 or H77s cells transfected with PKR siRNA or control siRNA were wounded by scratching, and incubated for 48 h (A). Percent wounded area filled in with JFH1 and H77s cells (B). Mean ± SEM of six replicates. MTS assay: Proliferation was associated with PKR expression (C). Cells were transfected with pPKR, and then 20 µM c-Jun inhibitor (SP600125) and 10 µM c-Fos inhibitor (U0126) was added. MTS assay indicated that cell proliferation induced by PKR depended on both c-Jun and c-Fos pathways (D). Mean ± SEM of 10 replicates. **p<0.01, *p<0.05.</p

Down- and upregulation of PKR gene expression by PKR siRNA or by a PKR-expression plasmid, respectively, in liver cancer cell lines, Huh 7.5.1, JFH1 and H77s.

<p>Cells were transfected with either PKR siRNA or control siRNA, then PKR mRNA was quantified by real-time RT-PCR; PKR was knocked down (A). Cells were transfected with PKR-expression plasmid (pPKR) or control plasmid (pOS8), then subjected to real-time RT-PCR; PKR mRNA was upregulated by pPKR (B). Mean ± SEM of six replicates. **p<0.01. The amount of HCV core protein in JFH1 and H77s cells were measured by ELISA. HCV core protein was stably expressed in both cell types at least three days after transfection with the HCV-RNA (C). The amount of HCV mRNA in JFH1 and H77s cells was measured by real-time RT-PCR. HCV RNA was expressed in both cell types at least three days after transfection with the HCV-RNA (D). Mean ± SEM of four replicates. PKR and phosphorylated PKR protein expression evaluated by Western blotting; results confirmed PKR mRNA data (E).</p

Analysis with insertion of 2 electrodes.

<p><b>A)</b> External appearance of the phantom after puncture. <b>B)</b> Distance between the 2 electrodes (white arrow). <b>C)</b> Distance between the 2 electrodes as measured on CT. <b>D-F)</b> The angle of intersection of the 2 electrodes as measured on the simulator system (<b>D</b>), ultrasonography (<b>E</b>), and CT (<b>F</b>).</p

Analysis after puncture with 3 electrodes.

<p><b>A, B)</b> External appearance in the phantom study. <b>C)</b> Appearance on 3D-CT. This image largely corresponds to <b>B</b>. <b>D, E)</b> Distances measured on CT (<b>D</b>) and the simulator system (<b>E</b>) between the 3 electrodes.</p