A new fluorescence-based reporter gene vector as a tool for analyzing and fishing cells with activated wnt signaling pathway

Establishment and characterization of McA-RH7777 cells using virus-mediated stable overexpression of enhanced green fluorescent protein

Hepatocellular carcinoma (HCC), the most common primary tumor of the liver, has a poor prognosis, rapid progression. The aim of the current study was to establish a stable lentiviral expression vector for enhanced green fluorescent protein (EGFP) and to evaluate biological characteristics on HCC growth and migration following transfection of HCC cells with EGFP. McA-RH7777 cells were transfected with EGFP overexpression lentiviral vector. Cell activity and mobility were monitored with a Cell-IQ Analyzer. Transwell assays were performed to detect invasiveness and flow cytometry was performed for cell cycle analysis. A subcutaneous tumor rat model was established to analyze the stability of fluorescent protein expression. The result suggested no significant differences between wild-type and EGFP-overexpressing McA-RH7777 cells with regards to cell proliferation, activity, mobility, invasiveness and cell cycle. Green fluorescence was detected over 108 days of culturing. The subcutaneous tumor rat model demonstrated that EGFP expression had no influence on tumor growth and long-term expression was stable. The stable EGFP expression of the HCC transplanted tumor rat model may share biological characteristics with human liver cancer. The model established in the current study may be suitable for various applications, including research focusing on liver cancer metastasis and recurrence, interventional therapy, imaging diagnosis and drug screenings.

Display of human and rabbit monocyte chemoattractant protein-1 on human embryonic kidney 293T cell surface

Monocyte chemoattractant protein-1 (MCP-1/CCL2) is a protein that is secreted immediately upon endothelial injury, and thereby it plays a key role in inflammation via recruitment of leucocytes to the site of inflammation at the beginning and throughout the inflammatory processes. Aim of this study was to develop two separate cell lines displaying either human MCP-1 (HMCP-1) or rabbit MCP-1 (RMCP-1) on their surface. A DNA fragment containing HMCP-1- or RMCP-1-encoding sequence was inserted into a pcDNA plasmid. Escherichia coli cells strain TOP 10F' was separately transformed with the pcDNA/RMCP-1 or /HMCP-1 ligation mixture. Following the cloning and construct verification, human embryonic kidney cell line (HEK 293T) was transfected with either of the linearized plasmids. Plasmid integration into the genomic DNA of HEK 293T cells was verified by polymerase chain reaction (PCR). HMCP-1 and RMCP-1 expression was evaluated at RNA and protein levels by real-time PCR and flow cytometry, respectively. PCR products of the expected sizes were amplified from the chromosomal DNA of transfected HEK 293T cells, i.e. 644 bp for H-MCP1 and 737 bp for RMCP-1 constructs. Real-time PCR revealed that the copy numbers of RMCP1 and HMCP1 mRNA per cell were 294 and 500, respectively. Flow cytometry analysis indicated 85% for RMCP-1 and 87% for HMCP-1 expression levels on the surface of transfected cells, when compared with an isotype control. The experiments thus confirmed that the MCP-1 genes were integrated into the HEK 293T genomic DNA and the encoded proteins were stably expressed on the cell surface.