[Metabolomics and its application in malignant tumors].

Metabolomics is a new science and technology, which it refers to a holistic analytical approach to all the low molecular weight metabolites in an organism or a cell. In this paper, the definition and objective of metabolomics are provided, and the current application of metabolomic research in malignant tumors (diagnosis and therapy) are summarized.

Differential expression of Epstein-Barr virus-encoded RNA and several tumor-related genes in various types of nasopharyngeal epithelial lesions and nasopharyngeal carcinoma using tissue microarray analysis.

Studies have revealed that Epstein-Barr virus (EBV) infection, genetic aberration, and environmental factors are of importance in the development of nasopharyngeal carcinoma (NPC), although the definite mechanism remains to be fully elucidated. The aim of our study is to investigate using tissue microarray analysis whether differential expression of EBV-encoded small RNA-1 (EBER-1) and several tumor-related genes were associated with NPC carcinogenesis. Immunohistochemistry and in situ hybridization were performed on tissue microarrays containing 148 NPCs and 164 noncancerous nasopharyngeal epithelia (NPE) with different morphologic features. We found that overexpressions of EBER-1 hybridization signals, p53, p21ras, and bcl-2 proteins and loss expressions of p16 and p27 proteins were significantly increased in NPC tissues compared with normal NPE and hyperplastic NPE (P

The role of NGX6 and its deletion mutants in the proliferation, adhesion and migration of nasopharyngeal carcinoma 5-8F cells.

OBJECTIVE: To demonstrate the subcellular localization of nasopharyngeal carcinoma (NPC)-associated gene 6 (NGX6) and its basic structure and function. METHODS: The deletion mutants of NGX6 were constructed by one-step PCR and transfected into NPC cell line 5-8F. The subcellular location of NGX6 or its mutants was detected by immunofluorescence staining of cytoplasm (CYTO) and nuclear protein, and immunoelectron-microscopic analysis. The role of NGX6 and its mutants in the proliferation, adhesion and migration of NPC 5-8F cells was detected using the following assays: growth curve, colony formation in soft agar, cell adhesion, in vitro Matrigel invasion, and in vitro scratch wound healing. RESULTS AND CONCLUSIONS: NGX6 and its mutants were distributed on the plasma membrane, nuclear membrane, endoplasmic reticulum membrane, and other membrane structures in the cytosol. The deleted domains did not affect its distribution in 5-8F cells. NGX6 could increase the adhesion but inhibited the proliferation, growth and migration of 5-8F cells. The epidermal growth factor-like domain and CYTO region were found to be important for NGX6 to modulate cell adhesion, and CYTO was found to be essential for NGX6 involved in the regulation of growth, proliferation, and migration of 5-8F cells.

[Function of a novel brain-specific gene LRRC4].

OBJECTIVE: To study the suppressive effect of LRRC4 gene on human glioma U251 cells and further investigate its biological functions. METHODS: H&E, DNA and AgNORs stainings were performed on LRRC4-transfected U251 cells, mock-transfected U251 cells and non-transfected U251 cells, respectively. Quantitative analysis including cell morphometry, DNA content, DNA ploidy, silver stained argyrophilic nucleolar organizer regions (AgNORs) were investigated by image analysis. Flow cytometry was employed to determine the difference of cell cycle distribution and MTT staining was used to elucidate the activity of the LRRC4-transfected U251 cells. RESULTS: The morphological cell parameters such as area, perimeter and diameter, DNA content, chromosomal aneupoloidy, mean area of AgNORs particles and mean nucleus area of the LRRC4-transfected U251 cells were remarkably decreased compared to those of the mock-transfected and non-transfected U251 cells (P < 0.05, P < 0.01). Meanwhile, significant accumulation of cells in G(0)/G(1) phase but decrease of cells in S and G(2)/M phase, was observed in transfected U251 cells compared to those of the mock-transfected and non-transfected U251 cells (P < 0.05, P < 0.01). MTT staining showed that proliferation activity of both the mock- and non-trasfected U251 cells was significantly higher than that of the U251 cells transfected with LRRC4 gene (P < 0.01). CONCLUSION: LRRC4 gene might be involved in tumor suppression by restraining DNA synthesis and the nucleoli organizer regions-associated proteins, keeping the cell cycles in phase G(0)/G(1) and reducing proliferation activity of the glioma cells. Morphometry combined with other techniques such as flow cytometry and MTT staining can well elucidate the biological function of novel genes.

[Expression of c-terminal of Parkin in E. coli and the preparation of antiserum].

OBJECTIVE: To clone and express 3'-terminal of Parkin gene in E. coli, and prepare its antiserum for further study. METHODS: The glutathion-sulfate-transferase (GST) fusion expression plasmid of 3'-terminal of Parkin gene (937-1959 bp) was constructed and transferred to JM 105. After being treated with Triton-100 (1%) and Tween-20 (1%) and purified with affinity chromatograph, GST-Parkin C was used to immunize New Zealand rabbits to acquire antiserum. Antiserum was analysed with immunoblot. RESULTS: The GST-Parkin C protein was expressed in JM 105, existing in the form of inclusion body with a molecular weight of around 42 kD; The purity of GST-Parkin C was up to 95%; the titer of antiserum was 1:64; Immunoblotting showed that the prepared antiserum could react specifically with 51.6 kD protein extracted from the mouse brain. CONCLUSION: A high level of expression of GST-Parkin C is obtained in JM 105, and its antiserum can be prepared successfully.