Pi-Xian Zhang

Publications (2)0.53 Total impact

• Article: Regulation of neutrophil gelatinase-associated lipocalin expression by C/EBPβ in lung carcinoma cells.

  Pi-Xian Zhang, Jing-Xia Chang, Jian-Jun Xie, Hua-Min Yuan, Ze-Peng DU, Fa-Ren Zhang, Zhuo Lü, Li-Yan Xu, En-Min Li
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  ABSTRACT: Neutrophil gelatinase-associated lipocalin (NGAL), a member of the lipocalin family, has been found to be overexpressed in a variety of tumors, including lung adenocarcinomas. However, the mechanism by which NGAL expression is regulated in lung carcinoma needs further evaluation. In this study, immunohistochemistry was employed to analyze the expression of NGAL in lung carcinoma tissue samples, including lung squamous carcinomas, adenocarcinomas, adenosquamous carcinomas and bronchial alveolar cell carcinomas. The results showed that NGAL was expressed in 82.61% (19/23) of the samples. RT-PCR and immunofluorescent staining showed that NGAL was localized to the cytoplasm in lung carcinoma cell lines. To explore the transcriptional regulation mechanism of NGAL basal expression in lung carcinoma, a 1515-bp fragment (-1431 to +84) of the NGAL promoter region was cloned and a series of deletion and mutation constructs were generated. These constructs were analyzed using the luciferase reporter assay. The results indicated that the cis-acting elements important for the basal activity of NGAL transcription were likely located between -152 and -141. Further analysis using site-directed mutagenesis and the luciferase reporter assay suggested that the C/EBP binding sites were responsible for the activity of the NGAL promoter. Finally, the binding ability and specificity of the transcription factors were determined by electrophoretic mobility-shift assay (EMSA). The results showed that C/EBPβ was able to bind to the -152 and -141 segments. Taken together, these findings suggest that NGAL is expressed in lung carcinomas and that NGAL expression is mediated by the binding of C/EBPβ to the -152 and -141 segment of the NGAL promoter.
  Oncology letters 11/2012; 4(5):919-924. · 0.11 Impact Factor
• Article: Expression of NGAL and NGALR in human embryonic, fetal and normal adult tissues.

  Pi-Xian Zhang, Fa-Ren Zhang, Jian-Jun Xie, Li-Hua Tao, Zhuo Lü, Xiu-E Xu, Jian Shen, Li-Yan Xu, En-Min Li
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  ABSTRACT: This study investigated the distribution of neutrophil gelatinase-associated lipocalin (NGAL) and neutrophil gelatinase-associated lipocalin receptor (NGALR) in human embryonic, fetal and normal adult tissues. Tissue microarray technology was used to perform immunohistochemical examination on human embryos, fetuses at 4-22 weeks of gestation and adult tissue specimens. Results demonstrated that during the development of the nervous system, NGALR was prevalent in the neural tube and cerebrum, and NGAL was only detected in the stellate cells of the cerebrum and the Purkinje cells of the cerebellum. NGAL and NGALR were expressed in the lung alveolar epithelium and in the gastrointestinal tract in embryos, but were almost undetectable in later developmental stages. In the embryonic adrenal glands, the two proteins demonstrated moderate positivity in the cortex and the medulla. In adults, NGAL was particularly present in the cells of the inner and outer layers of the cortex and was absent in the medulla, while NGALR exhibited strong positivity in the cortex and the medulla. Evident expression of NGAL and NGALR was observed throughout development in the neutrophil-rich sites, the renal tubule epithelium and certain gland epithelia of the gastrointestinal tract, but was undetectable in the heart, liver and thyroid gland. Taken together, these results demonstrated that the expression of NGAL and NGALR was time-specific and highly tissue‑specific. Correlations between their expression in embryogenesis and carcinogenesis should be examined.
  Molecular Medicine Reports 07/2012; 6(4):716-22. · 0.42 Impact Factor