Mechanism Of Maintaining Basal-like Breast Cancer Phenotype By WNT5B And Targeted Therapy Under Image Monitoring

Breast cancer is the leading cause of cancer-related death in women worldwide.Metastatic breast cancer has very poor prognosis,mostly related to basal-like breast cancer(BLBC).BLBC is associated with aggressive behavior,stem-like phenotype,high histological grade,poor clinical features,and high rates of recurrences and/or metastasis.However,the mechanism of BLBC property shaping remains obscure.Objective:This study aimed to identify the key factors for BLBC phenotype shaping,and explore a novel treatment for BLBC,which can be monitored under molecular imaging.Methods:We collected seventeen normal breast/breast cancer cell lines from the CBCAS(Cell Bank of the Chinese Academic of Sciences)and one hundred and twenty formalin-fixed breast cancer tissues from the department of pathology(Sir Run Run Shaw Hospital).This study was mainly divided into four sections.I:Cell lines and breast cancer tissues were used for breast cancer subtype-markers,Wingless/Integrated(Wnt)targets,Wnt constitutive components,and epithelial mesenchymal transition(EMT)markers evaluation by western blot,RT-PCR,immunohistochemistry(IHC)and immunofluorescence staining.?:Nine online platforms(cBioPortal,CCLE,GEPIA,etc.)were used for above-mentioned maker analyses at mRNA level,or for protein-protein interaction(PPI)analyses of Wnt3a,Wnt5a and Wnt5b.?:Lentivirus mediated shRNA was used for WNT5B knock-down,and the phenotype changes were evaluated after knock-down of WNT5B.IV:Two in vivo molecular imaging techniques(fluorescence imaging based on red fluorescent protein mStrawberry,and ultrasound imaging)were used for monitoring and evaluating the growth of subcutaneous tumors after knock-down of WNT5B,Wnt5b.targeted therapy by LGK-974,or CKla-targeted therapy by pyrvinium.Results:We identified Wnt5b as a key regulatory factor that govermed the properties of BLBC by activating canonical and non-canonical WNT signaling.Wnt5b exhibited basal-like specificity in cells and clinical tissue samples both at the mRNA and protein levels and also showed good correlation with basal-like properties at the mRNA level.Also,Wnt5b was a promising therapeutic target for LGK-974 treatment.In addition,we identified that CKla was expressed at a low level in BLBC and that the activation of CK1? by pyrvinium was an altermative strategy for BLBC treatment.Conclusion:Wnt5b is not only a diagnostic biomarker but also a potential therapeutic target of BLBC,which may provide the opportunity to develop new targeted molecular imaging technique for early diagnosis and effective treatment of BLBC.