Jianguang Zhou

Publications (3)11.63 Total impact

• Article: SGEF enhances EGFR stability through delayed EGFR trafficking from early to late endosomes.

  Hongtao Wang, Shan-Hu Li, Hailiang Li, Changling Li, Kaopeng Guan, Guolan Luo, Lan Yu, Rui-Qin Wu, Xiaoqing Zhang, Jian Wang, Jianguang Zhou
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  ABSTRACT: Previously we demonstrated an elevated SGEF expression in clinical specimens with prostate cancer and implicated the role of SGEF in prostate tumorigenesis. However, the molecular mechanism behind the SGEF regulation of prostate cancer development is not known. In this study, we show that SGEF expression delays epidermal growth factor receptor (EGFR) degradation in prostate cancer cells and is independent from its guanine nucleotide exchange (GEF) function. We further show that the delayed degradation is due to a delay in EGFR trafficking from early to late endosomes and not to a decrease in EGFR ubiquitination. Finally, we show that depletion of SGEF significantly inhibits EGF induced EGFR signaling cascade and cell migration in the prostate cancer cells. We report for the first time a SGEF function for RhoG that excludes GEF and the ability of SGEF to enhance EGFR stability and sig¬naling by delaying its lysosomal sorting and degradation. This could be one mechanism by which SGEF contributes to prostate cancer progression.
  Carcinogenesis 05/2013; · 5.70 Impact Factor
• Article: SGEF is overexpressed in prostate cancer and contributes to prostate cancer progression.

  Hongtao Wang, Ruiqin Wu, Lan Yu, Feima Wu, Shanhu Li, Yali Zhao, Hailiang Li, Guolan Luo, Jian Wang, Jianguang Zhou
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  ABSTRACT: The purpose of this study was to investigate the potential roles of the SH3-containing guanine nucleotide exchange factor (SGEF) in human prostate cancer. Experimental data showed that SGEF was overexpressed in human prostate cancer cells and specimens. The reduction of SGEF expression through an SGEF-targeting siRNA in androgen-independent C4-2 and C4-2B cells suppressed both anchorage-dependent and anchorage-independent growth. In addition, the androgen receptor (AR) antagonist bicalutamide further strengthened this inhibitory effect due to the suppression of the elevated AR transactivation after knockdown of SGEF. Collectively, our results provide the first demonstration that SGEF is a novel promoter of human prostate cancer progression and development.
  Oncology Reports 07/2012; 28(4):1468-74. · 1.84 Impact Factor
• Source

  Available from: PubMed Central

  Article: Spondin-2 (SPON2), a more prostate-cancer-specific diagnostic biomarker.

  Xiaolong Qian, Changling Li, Bo Pang, Meng Xue, Jian Wang, Jianguang Zhou
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  ABSTRACT: Prostate-specific antigen (PSA) screening, although common, has recently been called into question. To find prostate cancer (PCa) diagnostic biomarkers that can make up for the defects of PSA, we compared the secretomes of several benign and PCa cell lines, selected candidate molecules, and then confirmed their clinical value. We first identified extracellular proteins by two-dimensional gel electrophoresis (2-DE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification. We then validated the secreted proteins on a cellular level, and finally determined whether they could be used as PCa diagnostic biomarkers using prostate tissue and serum specimens of Chinese volunteers by immunohistostaining and sandwich ELISA. We obtained credible extracellular protein 2-DE graphs of prostate cell lines. The 5 spots that showed superior repeatability were selected for LC-MS/MS analysis, which identified seven candidate molecules. One of the candidate molecules, spondin-2 (SPON2), was only expressed in the conditioned media (CM) of androgen receptor (AR) positive PCa cell lines. Using tissue microarray by immunohistostaining, we found SPON2 to be over-expressed in PCa. SPON2 staining was more intense in Gleason score sum 7-8 and in PCa patients with metastasis. By receiver operator characteristic (ROC) curve analysis, we found that the serum SPON2 level was elevated in PCa patients, showing sensitivity and specificity suitable for diagnostic use. We also found that SPON2 could be used to identify PCa patients with serum PSA levels no higher than 10 ng/ml from healthy elderly men. SPON2 is a new serum and histological diagnostic biomarker for PCa. It can avoid some of the problems of PSA testing and was here found to offer relatively high sensitivity and specificity relative to PSA.
  PLoS ONE 01/2012; 7(5):e37225. · 4.09 Impact Factor