Downregulation of Notch-regulated Ankyrin Repeat Protein Exerts Antitumor Activities against Growth of Thyroid Cancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Notch-regulated ankyrin repeat protein (NRARP) is recently found to promote proliferation of breast cancer cells. The role of NRARP in carcinogenesis deserves extensive investigations. This study attempted to investigate the expression of NRARP in thyroid cancer tissues and assess the influence of NRARP on cell proliferation, apoptosis, cell cycle, and invasion in thyroid cancer.</p><p><b>METHODS</b>Thirty-four cases with thyroid cancer were collected from the Department of General Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine between 2011 and 2012. Immunohistochemistry was used to detect the level of NRARP in cancer tissues. Lentivirus carrying NRARP-shRNA (Lenti-NRARP-shRNA) was applied to down-regulate NRARP expression. Cell viability was tested after treatment with Lenti-NRARP-shRNA using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and cell cycle distribution were determined by flow cytometry. Cell invasion was tested using Transwell invasion assay. In addition, expressions of several cell cycle-associated and apoptosis-associated proteins were examined using Western blotting after transfection. Student's t-test, one-way analysis of variance (ANOVA), or Kaplan-Meier were used to analyze the differences between two group or three groups.</p><p><b>RESULTS</b>NRARP was highly expressed in thyroid cancer tissues. Lenti-NRARP-shRNA showed significantly inhibitory activities against cell growth at a multiplicity of infection of 10 or higher (P < 0.05). Lenti-NRARP-shRNA-induced G1 arrest (BHT101: 72.57% ± 5.32%; 8305C: 75.45% ± 5.26%) by promoting p21 expression, induced apoptosis by promoting bax expression and suppressing bcl-2 expression, and inhibited cell invasion by suppressing matrix metalloproteinase-9 expression.</p><p><b>CONCLUSION</b>Downregulation of NRARP expression exerts significant antitumor activities against cell growth and invasion of thyroid cancer, that suggests a potential role of NRARP in thyroid cancer targeted therapy.</p>

The role of tissue factor pathway inhibitor-2 gene in gallbladder cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To examine the expression of tissue factor pathway inhibitor-2 (TFPI-2) in gallbladder cancer (GBC) and to investigate the anti-cancer activities of TFPI-2 against the growth of GBC.</p><p><b>METHODS</b>TFPI-2 expression in gallbladder normal tissues, gallbladder polyp (GBP) tissues and GBC tissues were examined by reverse transcriptase polymerase chain reaction (RT-PCR), Western blot and immunohistochemical staining. Adenovirus carrying human TFPI-2 gene (Ad5-TFPI-2) were constructed and its anti-cancer effects were investigated in xenograft tumors. Xenograft tumors were constructed by injection of GBC-SD and SGC-996 cells into the flank of nude mice and the volume of xenograft tumors was measured every 3 days until the sacrifice of mice. The apoptosis index of xenograft tumors was examined by TUNEL assay. The status of Bax, Bcl-2 and caspase-3 was examined by Western blot assay.</p><p><b>RESULTS</b>TFPI-2 expression was profoundly lower in GBC tissues (87.0%) when compared to normal tissues (23.3%) and GBP tissues (52.2%; χ(2) = 21.104, P = 0.000). Ad-TFPI-2 significantly inhibited the growth of xenograft tumors in nude mice. Ad-TFPI-2 inhibited GBC-SD cell growth through the induction of apoptosis. The means of total apoptotic cells per field were much higher in Ad5-TFPI-2 group than those in PBS and Ad5-GFP groups. Ad5-TFPI-2 elevated the expression of Bax and cleaved caspase-3, while it decreased the expression of Bcl-2.</p><p><b>CONCLUSIONS</b>TFPI-2 gene and protein was down-regulated in GBC and the down-regulation of TFPI-2 may play a role in the tumorigenesis of GBC. Adenovirus-mediated TFPI-2 can inhibit GBC growth through the induction of apoptosis.</p>

Mechanism research in somatostatin reverting the chemosensitivity of GBC-SD cell line / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the mechanism of increasing chemosensitivity of gallbladder carcinoma stimulated by somatostatin.</p><p><b>METHODS</b>GBC-SD cells were divided into four groups: SST-alone-treated group, Doxorubicin (DOX)-alone-treated group and co-treated group (co-treatment of SST and DOX). In the control group, the cells were cultivated by medium only. In SST-alone-treated group, the cells were cultivated by medium with SST in the concentration of 75 microg/ml. In DOX-alone-treated group, the cells were cultivated by medium with DOX in the gradient concentrations of 5, 10, 20 microg/ml. In the co-treated group, cells were first cultivated by medium with 75 microg/ml SST for 24 h, followed by the addition of DOX in the gradient concentrations mentioned above. Cell viability curve was measured by MTT assay at 24, 48, 72 and 96 h, respectively. Meanwhile, the alterations of protein expressions of ICBP90 and Topo IIalpha after treatment of SST were examined by Western blot.</p><p><b>RESULTS</b>The treatment of SST alone on GBC-SD cells did not exert significantly inhibitory effect compared to the control group (P > 0.05). However, 24 h after the treatment of SST, the protein expressions of ICBP90 and Topo IIalpha were both up-regulated (P < 0.05).</p><p><b>CONCLUSION</b>Up-regulated the expression of ICBP90 by somatostatin maybe the cause of overexpression of Topo IIalpha, which leads to the enhanced lethal effect of DOX.</p>