Roles of MT-ND1 in Cancer.

The energy shift toward glycolysis is one of the hallmarks of cancer. Complex I is a vital enzyme complex necessary for oxidative phosphorylation. The mitochondrially encoded NADH: ubiquinone oxidoreductase core subunit 1 (MT-ND1) is the largest subunit coded by mitochondria of complex I. The present study summarizes the structure and biological function of MT-ND1. From databases and literature, the expressions and mutations of MT-ND1 in a variety of cancers have been reviewed. MT-ND1 may be a biomarker for cancer diagnosis and prognosis. It is also a potential target for cancer therapy.

Upregulated expression of S100A6 in human gastric cancer.

OBJECTIVE: The expression of S100A6 (calcyclin), a member of the S100 calcium binding protein family, is elevated in a number of malignant tumors, but there have been few reports about its expression in gastric cancer. The aim of this study was to investigate its expression regulations in human gastric cancer and noncancerous mucosa, and the response to chemotherapeutic drugs in the gastric cancer cell line. MATERIALS AND METHODS: In one matched gastric cancer sample pair, the serial analysis of gene expression (SAGE) experiment was conducted to compare the gene expression profiles between cancerous and adjacent tissues. To detect the expression regulations among more cancerous tissues, microarrays were carried out and real-time RT-PCR was conducted to validate the results. At the protein level, Western blot and tissue microarray (TMA) examination were further used to verify S100A6 expression. The regulation detection of S100A6 with flurouracil and doxorubicin at the mRNA and protein level was performed in the SGC7901 cell line. RESULTS: With the SAGE strategy, five times more S100A6 tags were identified in cancer tissues than in normal tissues. With the cDNA microarray, S100A6 was found to be significantly upregulated in 21 of 42 (50%) nonselective gastric cancers. In 10 other paired samples, the upregulation of S100A6 was consolidated with RT-PCR and Western blot analysis as well. A total of 14 endoscopy-sectioned gastric noncancerous lesions and corresponding normal gastric mucosa were also applied to profile the gene expression; both cDNA microarray and RT-PCR demonstrated no significant alterations of S100A6 at the mRNA level. TMA examination showed that 34 of 52 (65.4%) cancer samples were positively stained, while only 17 of 80 (21.3%) noncancerous lesions were positively detected and all nine normal mucosae were detected to be negative. An in vitro experiment showed that in the gastric cell line SGC-7901, S100A6 mRNA was detected to be upregulated from 24 to 72 h after treatment with 5 mg/L 5-flurouracil or 0.3 mg/L doxorubicin, and there were two wave upregulations of the S100A6 protein. CONCLUSION: The observed regulated expression of S100A6 suggests that it is associated with gastric cancer tumorigenesis and quantitation of S100A6 is a promising tool for diagnosis of gastric cancer.

Construction of an EGF receptor-mediated histone H1(0)-based gene delivery system.

PURPOSE: To construct an EGF receptor (EGF-R)-mediated histone H1(0)-based gene delivery system for gene therapy. METHODS: A recombinant DNA containing histone H1(0), EGF-R ligand, and endosomalytic domains was constructed in a prokaryotic vector and expressed in E. coli. Expression of the beta-galactosidase (beta-gal) gene in the tumor cells and tissues was observed after transduction of the beta-gal gene packaged by purified fusion proteins in vitro and in vivo. RESULTS: As an extension of the research on previously reported chemically synthetic composite polypeptide gene delivery systems, this genetically engineered polypeptide has proved to be capable of targeting the beta-galactosidase (beta-gal) gene into EGF-R-positive cancer cells both in vitro and in vivo. We also studied the time course of beta-gal gene expression in tumor tissues delivered in vivo by this polypeptide vector. At 24 h after administration, expression of the beta-galactosidase gene in tumor reached peak levels. The dosage optimization of administered polyplex was also investigated. The optimal dose of polyplex per mouse was 1 microg DNA packaged by 3 microg of composite polypeptide. CONCLUSIONS: The genetically engineered polypeptide based on histone H1(0) is a promising gene delivery system targeting EGF-R.

[In vitro experimental study of gene therapy for ovarian cancer with thymidine kinase gene of herpes simplex virus mediated by a non-viral GE7 delivery system].

OBJECTIVE: To investigate gene transfer efficiency of a novel target non-viral vector GE7 and effects of herpes simplex virus thymidine kinase (HSV(1)-tk)/ganciclovir (GCV) mediated by it in vitro. METHODS: The epidermal growth factor receptor (EGF-R) target gene delivery system GE7 was constructed. Human ovarian cancer cell line CAOV3 was transfected in vitro with beta-galactosidase (beta-gal) as reporter gene and HSV(1)-tk gene as therapeutic gene using this gene delivery system. By means of the assay of X-gal staining, Northern blotting, cell growth-inhibiting curve and so on, the transferring efficiency of exogenous genes and killing effects are observed. RESULTS: It showed that gene transfer efficiency is over 80%. When 10 mg/L GCV was put into ovarian cells transfected with HSV(1)-tk gene, 95% of cells were killed, and the apoptosis ratio reached up to 30. CONCLUSIONS: The GE7 gene delivery system is an effective and safe delivery system. GE7/HSV(1)-tk/GCV therapeutic gene system is appraising for ovarian cancer.