Fusion with matrix attachment regions enhances expression of recombinant protein in human HT-1080 cells.

Like endogenous proteins, recombinant foreign proteins produced in human cell lines also need post-translational modifications. However, high and long-term expression of a gene of interest (GOI) presents significant challenges for recombinant protein production in human cells. In this work, the effect of human matrix attachment region elements (MARs), including the ß-globin MAR (gMAR), chicken lysozyme MAR (cMAR), and a combination of these two, on the stable expression of GOI was assessed in human HT-1080 cells. After transfection with vectors containing the MAR elements and eGFP, stably HT-1080 cell pools were obtained under selective pressure. eGFP protein expression was analyzed by flow cytometry, while transgene copy number and eGFP mRNA expression levels were determined with qPCR and qRT-PCR technology. We found that MARs could not enhance transfection efficiency, but gMAR could significantly increase eGFP expression in stable HT-1080 cell pools by approximately 2.69-fold. Moreover, gMAR could also increase eGFP expression stability during long-term culture. Lastly, we showed that the effect of the MARs on transgenes was related to the gene copy number. In summary, this study found that MARs could both enhance the transgene expression and stability in HT-1080 cells.

CYP3A4 and microRNA-122 are involved in the apoptosis of HepG2 cells induced by ILs 1-decyl-3-methylimidazolium bromide.

Ionic liquids (ILs) as green alternatives for volatile organic solvents are increasingly used in commercial applications. It is necessary to explore the cytotoxic mechanism of ILs to reduce the risk to human health. For this purpose, cell viability, apoptosis, cytochrome P450 3A4 (CYP3A4), glucose transporter type 2 (GLUT2), and microRNA-122 (miR-122) gene expression in HepG2 cells was evaluated after IL exposure. The results showed that ILs reduced the viability of HepG2 cells through apoptotic cell death. Moreover, ILs markedly upregulated the transcription and protein levels of CYP3A4, but did not affect the expression of GLUT2 in either messenger RNA level or protein level. Finally, ILs increased the expression of miR-122 and inhibition of miR-122 with miR-122 inhibitor blocked ILs-induced apoptosis in HepG2 cells. This finding may contribute to an increased understanding of the in vitro molecular toxicity mechanism of ILs to further understand IL-related human health risks.