Yunguang Li

Shandong University, Chi-nan-shih, Shandong Sheng, China

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Publications (4)6.21 Total impact

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    ABSTRACT: Omi/HtrA2 promotes cell apoptosis in human cancer cells. Early studies showed that primary hepatocellular carcinoma requires Omi/HtrA2 expression for cell apoptosis. Additionally, the Omi/HtrA2 pro-apoptotic marker demonstrated a difference in some cell types. However, how the Omi/HtrA2 pro-apoptotic marker reacts during the process of hepatocellular carcinoma cell apoptosis remains to be determined. Thus, we investigated the role and possible mechanism of Omi/HtrA2 on hepatocellular carcinoma cell apoptosis using various hepatocellular carcinoma cell lines. The results were analyzed using RT‑qPCR and western blot analysis. In the present study, we found that Omi/HtrA2 was overexpressed in hepatocellular carcinoma cell lines and induced hepatocellular carcinoma cell apoptosis. Additiionally, the only manner in which Omi/HtrA2 participated in cell death in PLC cells may be dependent on IAP-binding. Omi/HtrA2‑inducing HepG2 cell apoptosis may mainly depend on its serine protease activity while both IAP-binding and its serine protease activity participated in Hep3B cell apoptosis. This result suggested that Omi/HtrA2 pro-apoptotic marker differs in various hepatocellular carcinoma cell lines. PLC cells were also devoid of the expression of ped/pea-15 as the substrate of Omi/HtrA2 serine protease while ped/pea-15 was overexpressed in HepG2 and Hep3B cells and ped/pea-15 expression was higher in HepG2 cells than that in Hep3B cells. These results showed that Omi/HtrA2 overexpression promotes hepatocellular carcinoma cell apoptosis and the ped/pea-15 expression level causes this difference of the Omi/HtrA2 pro-apoptotic marker in the various hepatocellular carcinoma cell lines.
    Oncology Reports 12/2014; · 2.19 Impact Factor
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    ABSTRACT: Background/Aims: To investigate Omi/HtrA2 expression and its clinical significance in hepatocellular carcinoma. Methodology: We analyzed Omi/HtrA2 expression in hepatocellular carcinoma, paracancerous tissues and normal hepatic tissues by immunohistochemistry, RT-PCR and Western blot. Hypoxia-inducible factor-1α (HIF-1α) expression was also detected in hepatocellular carcinoma samples by immunohistochemistry. Meanwhile, we retrospectively analyzed the relationship between Omi/HtrA2 expression and the survival times of the patients. Results: We found that Omi/HtrA2 over-expressed in hepatocellular carcinoma and was correlated with hepatocellular carcinoma differentiation, tumor size, portal vein invasion, clinical stage and lymph node metastasis. We also observed a significant inverse correlation between the expression of Omi/HtrA2 and HIF-1α in hepatocellular carcinoma. The Kaplan-Meier estimates showed that patients who were Omi/HtrA2 positive had much longer survival times than those who were Omi/HtrA2 negative. Both univariate and multivariate analysis using the Cox regression model indicated that Omi/HtrA2 expression was a significant factor for prognosis. Conclusions: Hepatocellular carcinoma cells may need Omi/HtrA2 expression for apoptosis and Omi/HtrA2 might be an important prognostic marker for primary hepatocellular carcinoma.
    Hepato-gastroenterology 07/2012; 60(121). · 0.91 Impact Factor
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    ABSTRACT: Hypoxia-inducible factor-1alpha (HIF-1alpha) plays an important role in regulating hepatoma cell apoptosis. However, conclusions of different studies about the effects of HIF-1alpha expression on hepatoma cell apoptosis remain controversial. Omi/HtrA2 promotes cell apoptosis in some human cancer cells. Our previous experiments have demonstrated that primary hepatocellular carcinoma may need Omi/HtrA2 expression for cell apoptosis. Thus, we investigated the effect of HIF-1alpha on hepatocellular carcinoma cell apoptosis and Omi/ HtrA2 expression. In our study we found that HIF-1alpha gene could suppress hepatoma cell apoptosis, and Omi/HtrA2 mRNA and protein expression decreased with HIF-1alpha expression increase while Bcl-2 mRNA and protein expression increased with HIF-1alpha expression increase in HepG2 cells under normoxia condition. Meanwhile, Omi/HtrA2 protein expression increased with HIF-1alpha expression decrease in HepG2 cells under hypoxia culture. Taken together, these results demonstrated that HIF-1alpha suppressed hepatocellular carcinoma cell apoptosis through inhibiting Omi/HtrA2 expression and upregulating Bcl-2 expression to impede Omi/ HtrA2 releasing from the mitochondrion. The present finding further enriched and supported the role of HIF-1alpha expression on cell apoptosis of hepatoma cells.
    Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics 05/2012; 20(5-6):213-20. · 0.92 Impact Factor
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    ABSTRACT: Hypoxia-inducible-1α (HIF-1α) expression was intimately correlated with apoptosis and proliferation of cancer cells. However, conclusions of different studies on the effects of HIF-1α expression on cell apoptosis and cell proliferation of hepatoma cells remain controversial. In view of the current status, we reassess its roles and possible mechanism in hepatoma cells. In order to acquire more convincing and reliable results, we used a Tet-on system to stably and effectively regulate HIF-1α expression in the HepG2 cells in vitro. In our study we not only confirmed some common conclusions of previous studies, but also acquired some different and significant results that HIF-1α facilitates cell proliferation and cell cycle through influencing the expression of cyclin A and cyclin D, and suppresses cell apoptosis through inducing the expression of survivin and Bcl-2. These results further enrich our knowledge on the role of HIF-1α expression on cell apoptosis and cell proliferation of hepatoma cells.
    Oncology Reports 11/2011; 27(2):573-8. · 2.19 Impact Factor