Effects Of Cetuximab Combined With Trametinib On Proliferation And Apoptosis Of Human Colon Cancer Cells

ObjectiveCetuximab is an epidermal growth factor receptor(EGFR)inhibitor and is widely used as an important molecular targeted drug for first-line treatment of advanced colorectal cancer.However,more than half of colon cancer patients are resistant to cetuximab due to KRAS,BRAF,and PIK3 mutations.Even patients with KRAS wild type.Even the patients with KRAS wild-type were only about 40%-60%effective with cetuximab.In order for more patients with colorectal cancer to benefit from the treatment of cetuximab,studies to reverse their resistance are needed.Trametinib is a mitogen-activated extracellular signal-regulated kinase 1/2 reversible inhibitor whose site of action is downstream of the KRAS-BRAF-MEK-ERK-MAPK signaling pathway.Mainly through the action of MEK protein,affecting the MAPK pathway and inhibiting cell proliferation.Therefore,this experiment is to study the effect of cetuximab and trametinib on proliferation and apoptosis of human colon cancer cells in vitro and whether the combination medication has a synergistic effect.MethodsThree different colon cancer cell lines SW48(KRAS wild type,BRAF wild type),SW480(KRAS G12V mutant,BRAF wild type),HT-29(KRAS wild type,BRAFV600E mutant)were selected as the study subjects.The cell lines were randomly divided into normal culture group,cetuximab group(200?g/ml),trametinib group(1nmol/1)and two drug combination groups.After 72 hours of culture in vitro,the cell proliferation ability was measured by CCK-8(Cell counting kit-8)method,and the apoptosis rate was detected by Annexin V-FITC/PI double staining method.Results1.The results of cell proliferation inhibition showed that after treatment with cetuximab,the proliferation rate of SW480 and HT-29 cells did not change significantly(P>0.05),and the proliferation rate of SW48 cells decreased significantly.After treatment with trametinib,the proliferation rate of the three cells was significantly decreased(P<0.01),and the combination of the two drugs could further inhibit the proliferation of the three cell lines(P<0.05).2.The results of flow cytometry showed that there was no significant difference in the effect of cetuximab alone on the apoptosis rate of the three cells(P>0.05).The single drug of trametinib had significant apoptosis-inducing effects on SW480 and HT-29(P<0.05),but not on SW48(P>0.05).Compared the drug combination group with the cetuximab group,the increase of apoptotic rate of HT-29 and SW480 cells was statistically significant(P<0.05),and there was no significant difference in the apoptosis rate of SW48(P>0.05).There was no statistical difference in the apoptotic rate between the two drug combination groups and the trametinib group(P>0.05).ConclusionsThe combination of cetuximab and trametinib can effectively inhibit colon cancer cell proliferation and induce apoptosis,and significantly increase the drug sensitivity of KRAS and BRAF mutant human colon cancer cell lines to cetuximab,and also improve the anti-tumor effect of KRAS and BRAF wild-type colon cancer cells to some extent.The combination of the two drugs has a synergistic anti-tumor effect in vitro.