Pro-apoptotic effect of a tumor suppressor gene WWOX on ovarian cancer stem cells and its mechanism / 中国组织工程研究

BACKGROUND:WWOX,a tumor suppressor gene,can affect the growth of ovarian cancer stem cells;however,there is no report on whether its mechanism of action is related to Hedgehog signaling pathway.OBJECTIVE:To investigate the effect and mechanism of overexpression of WWOX on the apoptosis of ovarian cancer stem cells.METHODS:pcDNA3.1-WWOX (pcDNA3.1-WWOX group) and pcDNA4.0-WWOX (pcDNA4.0-WWOX group) were transferred into ovarian cancer stem cells,respectively;and meanwhile,pcDNA3.1 (pcDNA3.1 group) and pcDNA4.0 (pcDNA4.0 group) were transferred into the cells.A non-transfection group (only with Lipofectamine2000) was set up.After cultured 48 hours,the levels of WWOX in the pcDNA3.1-WWOX group and pcDNA4.0-WWOX group were detected using western blot assay,and the cell proliferation and apoptosis were detected using MTT assay and flow cytometry,respectively.Western blot assay was also used to detect the levels of Hedgehog signaling pathway associated proteins,SHH,PTCH1,Gli-1,SMO and apoptosis-related protein Cleaved Caspase-3 in the cells.Cyclopamine,Hedgehog signaling pathway inhibitor,was used in ovarian cancer stem cells without transfection (cyclopamine group) and after the transfection of WWOX overexpression vector (WWOX+cyclopamine group) followed by 48 hours of culture,and then MTT,flow cytometry and western blot detections were performed.RESULTS AND CONCLUSION:(1) The expression level of WWOX in the pcDNA4.0-WWOX group was significantly higher than that in the pcDNA3.1-WWOX group (t=27.84,P=0.00).The ovarian cancer stem cells which were transfected with pcDNA4.0-WWOX were used to overexpress WWOX in the late experiment.(2) Overexpression of WWOX could inhibit the proliferation of ovarian cancer stem cells and promote the apoptosis of ovarian cancer stem cells.(3) Overexpression of WWOX could inhibit the expression of Gii-1,PTCH1,SMO and SHH in ovarian cancer stem cells,and promote the expression of Cleaved Caspase-3.(4) Cyclopamine could inhibit the expression of SHH,PTCH 1,Gli-1,SMO,and promote the expression of Cleaved Caspase-3.Cyclopamine had obvious inhibitory effect on Hedgehog signaling pathway.(5) Cyclopamine could enhance the apoptosis induced by overexpression of WWOX in ovarian cancer stem cells,and enhance the inhibition of proliferation of ovarian cancer stem cells induced by overexpression of WWOX.To conclude,WWOX effects on proliferation and apoptosis of ovarian cancer stem cells may be related to the inhibition of Hedgehog signaling pathway.

Perfluorocarbon attenuates lipopolysaccharide-mediated inflammatory responses of alveolar epithelial cells in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Toll-like receptor-4 (TLR-4) is integrally involved in lipopolysaccharide (LPS) signaling and has a requisite role in the activation of nuclear factor-κB (NF-κB). The exact mechanisms that lend perfluorocarbon (PFC) liquids a cytoprotective effect have yet to be elucidated. Therefore we examined in an in vitro model the cytoprotective effect of PFC on LPS-stimulated alveolar epithelial cellls (AECs).</p><p><b>METHODS</b>AECs (A549 cells, human lung adenocarcinoma cell line) were divided into four groups: control, PFC, LPS and LPS + PFC (coculture group) groups. Intercellular adhesion molecule-1 (ICAM-1) was detected by ELISA, tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) were detected by radioimmunological methods. The expression of TLR-4 mRNA and protein was detected by real time PCR and Western blotting, respectively. The activation of NF-κB was detected by Western blotting (proteins of I-κBa and NF-κB p65).</p><p><b>RESULTS</b>ICAM-1, TNF-α and IL-8 were significantly increased in LPS-stimulated AECs groups. The expression of TLR-4 mRNA and protein in LPS-stimulated groups was markedly increased. Meanwhile, NF-κB was activated as indicated by the significant degradation of IκB-α and the significant release of NF-κB P65 and its subsequent translocation into the nucleus. There were no significant effects of PFC alone on any of the factors studied while the coculture group showed significant downregulation of the secretion of ICAM-1, TNF-α and IL-8, the expression of TLR-4 mRNA and the activity of NF-κB.</p><p><b>CONCLUSIONS</b>Taken together, our results demonstrate that LPS can induce AEC-related inflammatory injury via the activation of TLR-4 and subsequent activation of NF-κB. PFC is able to protect AECs from LPS-induced inflammatory injury by blocking the initiation of the LPS signaling pathway, which is indicated by the significant decrease of TLR-4 expression and NF-κB activation.</p>

Hypoxia increases the expression of heparitinase and the invasiveness through the hypoxia inducible factor-1alpha dependent pathway in human ovarian cancer cell line SKOV3 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the heparitinase (HPA) expression and cell invasiveness in human ovarian cancer cell line SKOV3 during hypoxia, and explore their relationship with hypoxia inducible factor-1alpha (HIF-1alpha).</p><p><b>METHODS</b>SKOV3 cells were incubated with normoxia, hypoxia, and hypoxia plus rapamycin, respectively. SKOV3 cells of hypoxia group were incubated in 5% CO2 + 1% O2. Cells in hypoxia plus rapamycin group were incubated with 10 ng/ml of rapamycin before cultured under hypoxic condition. Cells in each group were collected for analysis after incubated with hypoxia for 12, 24, and 36 hours, respectively. Western blotting and RT-PCR were performed to detect the expressions of HIF-1alpha and HPA. Cell invasiveness was measured by matrigel invasion assay.</p><p><b>RESULTS</b>Western blotting showed that the expression of HIF-1alpha significantly increased compared with normoxic group (P < 0.05). However, hypoxia had no obvious impact on HIF-1alpha mRNA expression. The expressions of HPA protein and mRNA of SKOV3 cells of hypoxia group were significantly higher than normoxic group (P < 0.05). The up-regulation of HPA expression in hypoxic group decreased after the utilization of rapamycin. The cell invasion of hypoxic group was significantly higher than that of normoxic group (P < 0.05); meanwhile, the expression of HPA was positively correlated with the invasiveness of SKOV3 cells (r = 0.9863, P < 0.05).</p><p><b>CONCLUSION</b>Hypoxia may promote the expression of HPA and the invasiveness of SKOV3 cells through the HIF-1alpha pathway, which plays an important role in the pathogenesis of ovarian cancer.</p>