The Study To Effects Of MEK5 Small Molecule Inhibitors On The Biological Behavior Of K-ras Mutant Colorectal Cancer Cells

ObjectiveThe occurrence and development of colorectal cancer is caused by many factors,such as Congenital heredity and acquired social environment,it is a complex process involving multiple genes,multiple signal transduction pathways,and multi-stage abnormal changes.The abnormal activation of epidermal growth factor receptor signaling pathway plays an important role in the occurrence and development of colorectal cancer.However,when the K-ras gene is mutated,the patients of colorectal cancer with.K-ras mutations cannot benefit from targeted therapy of epidermal growth factor receptor antagonists.At present,the clinical trials of Raf protein antagonists have failed,and the search for the downstream target of Ras protein therapy has become an important breakthrough.The main purpose of this study is to investigate the value When the MEK5 signaling pathway is inhibited in targeted therapy for the colorectal cancer with K-ras gene mutations through the small molecule inhibitors of MEK5.On the basis of previous studies,this satudy is to further confirmed that MEK5 was important targets of EGFR-MAPK downstream genes for colorectal cancer with the K-ras gene mutation,and provide experimental evidence of the molecular treatment target for colorectal cancer with the K-ras gene mutation.MethodsQT-PCR and Western blot assay were used to detect the transcription level of MEK5/ERK5 mRNA and the expression level form of MEK5 protein to the colorectal cancer cells SW480 with K-ras gene mutations and the K-ras genes in wild type colorectal cancer HT29 cells that treated by different concentrations of the small molecule MEK5 inhibitor.MTS assay was used to detect cell proliferation,Flow cytometry,Transwell and cell scratch assay were used to detect the changes of cell growth,apoptosis,invasion and migration ability of the two groups.ResultsThe results of QT-PCR and Western blot showed that the expression levels of MEK5 and ERK5 mRNA in the SW480 cell and the expression level of MEK5 protein are more upward than the HT29 cell,and the difference is statistically significant.Compared with HT29 cell,the growth,invasion and migration ability of SW480 cell are significantly inhibited by the small molecule inhibitors with same concentration,and the apoptosis was accelerated,the difference was statistically significant.Conclusion1.The small and specific molecule inhibition(BIX02189)of MEK5 mediated the structure and protein expression inhibition for MEK5 gene of colorectal cancer SW480 cells with K-ras gene mutation.Compared with colorectal cancer HT29 cells,a wild type K-ras gene,the molecule inhibition can downregulate the expression of MEK5 gene in SW480 cells.2.After the small molecule inhibitor specifically mediated the expression of MEK5 gene,the proliferation,invasion and migration ability of colorectal cancer SW480 cells with K-ras gene mutation were significantly reduced,meanwhile,accelerated SW480 cells apoptosis.3.This experiment further confirmed that MEK5 gene is closely related to the occurrence and development of and colorectal cancer wiht K-ras gene mutation.On the basis of previous studies,this satudy is to further confirmed that MEK5 was important targets of EGFR-MAPK downstream genes for colorectal cancer with the K-ras gene mutation,and provide experimental evidence of the molecular treatment target for colorectal cancer with the K-ras gene mutation.4.This experiment were used cells in vitro instead of the tumor cells in the body,taking into account the survival environment and internal environment differences of the cell in vitro,andthe survival environment are easy to change,therefore,the results also have some limitations,and then a experiments of animal tumor xenograft models in vivo should further be studied for providing a more reliable experimental basis.