Transcription factor NF-Y regulates mdr1 expression through binding to inverted CCAAT sequence in drug-resistant...

Area of Science:

• Molecular Biology
• Cancer Research
• Genetics

Background:

• Multidrug resistance (MDR) is a significant challenge in cancer therapy.
• The multidrug resistance-1 (MDR1) gene plays a crucial role in drug efflux.
• Understanding MDR1 regulation is vital for overcoming treatment resistance.

Purpose of the Study:

• To investigate the transcriptional regulation of the MDR1 gene in human squamous carcinoma cells.
• To identify the transcription factors involved in MDR1 gene expression.
• To compare MDR1 expression and regulation in drug-sensitive and drug-resistant cell lines.

Main Methods:

• Reverse Transcription Polymerase Chain Reaction (RT-PCR) for mRNA expression analysis.
• Electrophoretic Mobility Shift Assay (EMSA) to detect DNA-protein interactions.
• Chromatin Immunoprecipitation (ChIP) assay to confirm transcription factor binding.
• Luciferase reporter assay to assess promoter activity.
• Western blotting (implied by protein level discussion) and Hoechst dye staining.

Main Results:

• MDR1 mRNA and protein expression were significantly higher in multidrug-resistant SCCTF cells compared to sensitive SCCKN cells.
• NF-Y transcription factor was identified as a key regulator, binding to the MDR1 promoter region in resistant cells.
• The inverted CCAAT sequence within the MDR1 promoter is crucial for its activity.
• Higher levels of NF-YA protein were observed in SCCTF cells, correlating with increased MDR1 function.

Conclusions:

• NF-Y directly binds to the MDR1 promoter and positively regulates its activity.
• Elevated NF-YA protein levels contribute to increased MDR1 expression and function in resistant cells.
• Targeting the NF-Y/MDR1 interaction could be a strategy to overcome multidrug resistance in squamous carcinoma.