[Construction and identification of Mdr-1-shRNA eukaryotic expression vector]

Area of Science:

• Molecular Biology
• Gene Expression Regulation
• Cancer Research

Background:

• The multidrug resistance gene 1 (mdr-1) and its protein product P-glycoprotein (P-gp) are implicated in drug resistance in cancer cell lines.
• Understanding the role of mdr-1 in K562/A02 cells requires effective methods to modulate its expression.

Purpose of the Study:

• To construct and validate a short hairpin RNA (shRNA) eukaryotic expression vector targeting the mdr-1 gene.
• To assess the vector's efficacy in inhibiting mdr-1 mRNA and P-gp expression in K562/A02 cells.

Main Methods:

• Synthesized shRNA targeting specific sequences of mdr-1 mRNA.
• Cloned target sequences into the pGCSilencer-U6-neo-GFP plasmid to create recombinant plasmids (pGY1-1, pGY1-2, pGY1-3).
• Confirmed recombinant plasmid sequences via DNA sequencing and PCR electrophoresis.
• Transfected K562/A02 cells with recombinant plasmids using lipofection.
• Quantified mdr-1 mRNA inhibition using real-time PCR and P-gp expression using Western blot post-transfection.

Main Results:

• Successful cloning of specific oligonucleotides into the expression vector was confirmed.
• Transfection with recombinant plasmids significantly reduced mdr-1 mRNA levels in K562/A02 cells compared to controls.
• Reduced P-glycoprotein expression was observed in transfected cells, indicating successful gene silencing.

Conclusions:

• A functional shRNA eukaryotic expression vector targeting mdr-1 has been successfully established.
• The developed vector effectively inhibits mdr-1 mRNA and P-gp expression in K562/A02 cells.
• This provides a valuable tool for further investigation into the function of mdr-1 in this cell line.