基于转录组学分析探讨PI3K/Akt通路在三阴性乳腺癌表阿霉素耐药中的作用OA

Objective To establish an epirubicin(EPI)-resistant murine triple-negative breast cancer(TNBC)(4T1/EPI)cell line and evaluate its biological characteristics and drug resistance.Methods The EPI-resistant cell line 4T1/EPI was developed through intermittent induction with gradually increasing EPI concentrations in vitro.Morphological changes were observed under an inverted microscope.Drug resistance index(MTT assay),cell doubling time(CCK-8 assay),and migration ability(wound healing assay)were evaluated.Western blot was used to detect the expression of drug resistance-related proteins.Transcriptome sequencing and KEGG pathway enrichment analysis were performed to identify the pathways and targets involved in EPI resistance,followed by experimental validation.Results The 4T1 cells eventually grew normally in a medium containing 100 ng/mL EPI,confirming the establishment of the 4T1/EPI resistant cell line.After stable resistance was acquired,morphological alterations were observed.Compared with their parental 4T1 cells,4T1/EPI cells showed significantly prolonged doubling time(P<0.01)and enhanced migration ability(P<0.05).Expression levels of drug resistance-related proteins MDR1,MRP1(P<0.01),and ABCG2(P<0.05)were elevated in 4T1/EPI cells.In vivo models also demonstrated significant EPI resistance in 4T1/EPI tumors in terms of tumor weight and volume.Transcriptome sequencing highlighted the involvement of the PI3K/Akt signaling pathway and ABC transporter pathway.Validation experiments showed the upregulation of Erbb3,Egfr,PI3K,and Akt(P<0.05)and significant downregulation of Fgfr1(P<0.01)in 4T1/EPI cells.Conclusion The EPI-resistant TNBC cell line 4T1/EPI was successfully established,exhibiting significant resistance in vitro and in vivo.The mechanism may involve the EPI-induced upregulation of Egfr and Erbb3,activating the PI3K/Akt pathway and subsequently enhancing ABC transporter expression.