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Guangzhou, China

Wang H.-C.,Guangzhou University | Chen C.,Higher Education Mega Center | Wang L.-N.,Higher Education Mega Center | Long Y.-F.,Higher Education Mega Center | And 4 more authors.
Clinical Laboratory | Year: 2013

The rapid increase of syphilis underscores a tremendous need to carefully evaluate many new serological tests for syphilis and choose efficient and economical strategies for syphilis screening, especially in the case of primary infection with low antibody titer. Between 2011 and 2012, 73 patients' sera samples were included in this retrospective study. They were either TRUST or TPPA reactive, either LA (latex agglutination) based auto3 TP or CLIA (chemiluminescence assay) based Architect Syphilis TP assay reactive. The contradictory weak response samples were further examined by FTA-Abs method. TPPA could not give reactive results in samples with antibody concentration less than 10 mIU. Auto3 TP reagent shows good linearity at low antibody titers and was more sensitive than TPPA, while the former does not show significant superiority compared to the Architect Syphilis TP assay at low antibody titer, except that it is suitable for adaptation on diverse automated chemistry analyzers.


Chen Y.,Guangzhou University | Tang Q.,Guangzhou University | Wu J.,Guangzhou University | Zheng F.,Guangzhou University | And 3 more authors.
Journal of Experimental and Clinical Cancer Research | Year: 2015

Background: Lung cancer is the most common cause of cancer-related deaths worldwide. Natural phytochemicals from traditional medicinal plants such as solamargine have been shown to have anticancer properties. The prostaglandin E2 receptor EP4 is highly expressed in human cancer, however, the functional role of EP4 in the occurrence and progression of non small cell lung cancer (NSCLC) remained to be elucidated. Methods: Cell viability was measured by MTT assays. Western blot was performed to measure the phosphorylation and protein expression of PI3-K downstream effector Akt, transcription factors SP1, p65, and EP4. Quantitative real-time PCR (qRT-PCR) was used to examine the mRNA levels of EP4 gene. Exogenous expression of SP1, p65, and EP4 genes was carried out by transient transfection assays. EP4 promoter activity was measured by Dual Luciferase Reporter Kit. Results: We showed that solamargine inhibited the growth of lung cancer cells. Mechanistically, we found that solamargine decreased the phosphorylation of Akt, the protein, mRNA expression, and promoter activity of EP4. Moreover, solamargine inhibited protein expression of SP1 and NF-κB subunit p65, all of which were abrogated in cells transfected with exogenous expressed Akt. Intriguingly, exogenous expressed SP1 overcame the effect of solamargine on inhibition of p65 protein expression, and EP4 protein expression and promoter activity. Finally, exogenous expressed EP4 feedback reversed the effect of solamargine on phosphorylation of Akt and cell growth inhibition. Conclusion: Our results show that solamargine inhibits the growth of human lung cancer cells through inactivation of Akt signaling, followed by reduction of SP1 and p65 protein expression. This results in the inhibition of EP4 gene expression. The cross-talk between SP1 and p65, and the positive feedback regulatory loop of PI3-K/Akt signaling by EP4 contribute to the overall responses of solamargine in this process. This study unveils a novel mechanism by which solamargine inhibits growth of human lung cancer cells. © 2015 Chen et al.


Yang L.,Guangzhou University | Tang Q.,Guangzhou University | Wu J.,Guangzhou University | Chen Y.,Guangzhou University | And 4 more authors.
Journal of Experimental and Clinical Cancer Research | Year: 2016

Background: Ursolic acid (UA), a natural pentacyclic triterpenoid, exerts anti-tumor effects in various cancer types including hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying this remain largely unknown. Methods: Cell viability and cell cycle were examined by MTT and Flow cytometry assays. Western blot analysis was performed to measure the phosphorylation and protein expression of p38 MAPK, insulin-like growth factor (IGF) binding protein 1 (IGFBP1) and forkhead box O3A (FOXO3a). Quantitative real-time PCR (qRT-PCR) was used to examine the mRNA levels of IGFBP1 gene. Small interfering RNAs (siRNAs) method was used to knockdown IGFBP1 gene. Exogenous expressions of IGFBP1 and FOXO3a were carried out by transient transfection assays. IGFBP1 promoter activity was measured by Secrete-Pair™ Dual Luminescence Assay Kit. In vivo nude mice xenograft model and bioluminescent imaging system were used to confirm the findings in vitro. Results: We showed that UA stimulated phosphorylation of p38 MAPK. In addition, UA increased the protein, mRNA levels, and promoter activity of IGFBP1, which was abrogated by the specific inhibitor of p38 MAPK (SB203580). Intriguingly, we showed that UA increased the expression of FOXO3a and that overexpressed FOXO3a enhanced phosphorylation of p38 MAPK, all of which were not observed in cells silencing of endogenous IGFBP1 gene. Moreover, exogenous expressed IGFBP1 strengthened UA-induced phosphorylation of p38 MAPK and FOXO3a protein expression, and more importantly, restored the effect of UA-inhibited growth in cells silencing of endogenous IGFBP1 gene. Consistent with these, UA suppressed tumor growth and increased phosphorylation of p38 MAPK, protein expressions of IGFBP1 and FOXO3a in vivo. Conclusion: Collectively, our results show that UA inhibits growth of HCC cells through p38 MAPK-mediated induction of IGFBP1 and FOXO3a expression. The interactions between IGFBP1 and FOXO3a, and feedback regulatory loop of p38 MAPK by IGFBP1 and FOXO3a resulting in reciprocal pathways, contribute to the overall effects of UA. This in vitro and in vivo study corroborates a potential novel mechanism by which UA controls HCC growth and implies that the rational targeting IGFBP1 and FOXO3a can be potential for the therapeutic strategy against HCC. © 2016 Yang et al.


Luo T.,Sun Yat Sen University | Wang G.,Higher Education Mega Center | Wang G.,Sun Yat Sen University
Optical Engineering | Year: 2016

This work provides a design and optimization method for total internal reflection (TIR) lenses based on slope-error tolerance analysis. This work focuses on how the slope error impacts the central luminous intensity (CLI) of a TIR lens. The concentration standard index (CSI) is introduced as a metric for analyzing the CLI, both locally and globally. A unique design method for improved manufacturing tolerance is introduced, and a way of optimizing the TIR lens design in order to achieve a better slope-error tolerance is presented by evaluating the CSI. Using the design method, a TIR lens is fabricated and this theoretical approach is then demonstrated by a comparison between the tested contours of the TIR surfaces. © 2016 The Authors.


Yie Y.,Guangzhou University | Zhao S.,Guangzhou University | Tang Q.,Guangzhou University | Zheng F.,Guangzhou University | And 5 more authors.
Molecular and Cellular Biochemistry | Year: 2014

Hepatocellular carcinoma (HCC), the major histological subtype of primary liver cancer, remains one of the most common malignancies worldwide. Due to the complicated pathogenesis of this malignancy, the outcome for comprehensive treatment is limited. Chinese herbal medicine (CHM) is emerging as a promising choice for its multi-targets and coordinated intervention effects against HCC. Ursolic acid (UA), a natural pentacyclic triterpenoid carboxylic acid found in CHM, exerts anti-tumor effects and is emerging as an effective compound for cancer prevention and therapy. However, the molecular mechanisms underlying the action of UA remain largely unknown. In this study, we showed that UA inhibited the growth of HCC cells and induced apoptosis in the dose- and time-dependent fashion. Furthermore, we found that UA induced phosphorylation of AMP-activated protein kinase alpha (AMPKα) and suppressed the protein expression of DNA methyltransferase 1 (DNMT1) in the dose-dependent manner. The inhibitor of AMPK, compound C blocked, while an activator of AMPK, metformin augmented the effect of UA on DNMT1 expression. In addition, UA suppressed the expression of transcription factor Sp1. Conversely, overexpression of Sp1 reversed the effect of UA on DNMT1 expression and cell growth. Collectively, our results show for the first time that UA inhibits growth of HCC through AMPKα-mediated inhibition of Sp1; this in turn results in inhibition of DNMT1. This study reveals a potential novel mechanism by which UA controls growth of HCC cells and suggests that DNMT1 could be novel target for HCC chemoprevention and treatment. © 2014, Springer Science+Business Media New York.

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