The effects of siRNA-mediated gene silencing of alpha-7 nicotinic acetylcholine receptors on drug resistance to oxaliplatin in colorectal cancer cell line
The effects of siRNA-mediated gene silencing of alpha-7 nicotinic acetylcholine receptors on drug resistance to oxaliplatin in colorectal cancer cell line
Khalil Hajiasgharzadeh,1Narges Dastmalchi,2,*
1. Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran 2. Department of Biology, University College of Nabi Akram, Tabriz, Iran.
Introduction: Colorectal cancer (CRC) is one of the most common cancers worldwide. Oxaliplatin (OXA) is one of the chemotherapy drugs used in this cancer. On the other hand, the alpha-7 nicotinic acetylcholine receptor (α7nAchR), which is one of the members of the nicotinic receptors family, has a crucial role in different types of cancers and the resistance to chemotherapy. The role of α7nAchR in CRC chemoresistance, especially in OXA-resistant cells, has not yet been identified. Therefore, this study was designed and performed to evaluate the impact of suppression of α7nAchR by siRNA on OXA-resistant cells.
Methods: OXA-resistant SW-480 cells were established by raising the concentration of OXA and exposing cells repeatedly. Then, the electroporation method was used to transfer siRNA sequencing to cells to inhibit α7nAchR expression. IC50 values of OXA and the combination of α7nAchR-siRNA and OXA were determined using the MTT assay. qRT-PCR was used to evaluate the expression of α7nAchR, MDR-1, Bcl-2, and Caspase-3 genes.
Results: The results indicated that suppression of α7nAchR expression could cause sensitization in OXA-resistant cells. This study also showed significant induction in α7nAchR mRNA expression in OXA-resistant cells compared to naïve cells. α7nAchR-siRNA transfection significantly reduced the expression of α7nAchR simultaneously with IC50 values. Also, following transfection with α7nAchR-siRNA, decreased expression of MDR-1 and Bcl-2 genes was observed along with increased expression of the Caspase-3 gene.
Conclusion: According to the findings of this study, α7nAchR has an important role in OXA chemosensitivity. Thus, α7nAchR may be considered a clinical marker in CRC drug resistance, and its suppression may be a potential therapeutic approach for CRC therapy.