基于VEGF/ANG通路探究固本抑瘤Ⅱ号对三阴性乳腺癌术后自发肺转移的作用机制OA

Objective To investigate the effects and mechanisms of Guben Yiliu No.2 in inhibiting postoperative lung metastasis of triple-negative breast cancer(TNBC)in mice by reducing tumor angiogenesis through the vascular endothelial growth factor/angiopoietin(VEGF/ANG)pathway.Methods Twenty-five female BALB/c mice were randomly divided into a blank group,model group,postoperative traditional Chinese medicine(TCM)group,whole-course TCM group,and epirubicin group,with 5 mice in each group.A spontaneous postoperative lung metastasis model of TNBC was established by orthotopic inoculation of 4T1-luciferase cells into the fourth mammary fat pad followed by surgical resection of the primary tumor.The postoperative TCM group received Guben Yiliu No.2(60 mL/kg·d)by gavage starting on postoperative day 3,while the whole-course TCM group received the same treatment beginning on day 3 after tumor inoculation.The epirubicin group received intraperitoneal injections of epirubicin(0.003 g/kg,twice weekly).The blank and model groups received equal volumes of normal saline.Lung metastasis was evaluated by small-animal in vivo bioluminescence imaging and micro-CT.Vasculogenic mimicry(VM)was detected by immunohistochemical staining for platelet endothelial cell adhesion molecule-1/periodic acid-Schiff(CD31/PAS).Protein expression levels of vascular endothelial growth factor A(VEGFA),angiopoietin-1(ANG1),angiopoietin-2(ANG2),and tyrosine kinase receptor 2(Tie2)in lung tissue were detected by Western blot.Serum VEGF levels were measured by enzyme-linked immunosorbent assay(ELISA).Expression of the tight junction protein-1(claudin-1)in lung tissue was detected by immunofluorescence.In vitro,pulmonary microvascular endothelial cells(PMVECs)were co-cultured with 4T1 cells to evaluate tube formation ability and vascular permeability.Results Compared with the model group,the whole-course TCM group showed significantly reduced fluorescence intensity of lung metastatic lesions,lung weight,and lung index(P<0.05),significantly decreased microvessel density(MVD)and VM density in lung tissue(P<0.05),and significantly enhanced claudin-1 fluorescence intensity(P<0.05).Serum VEGF levels and protein expression levels of VEGFA and ANG2 in lung tissue were significantly downregulated(P<0.05),whereas ANG1 and Tie2 expression levels showed an upward trend.In vitro experiments demonstrated that Guben Yiliu No.2 significantly inhibited the number of PMVEC tube structures,tube length,and node number(P<0.05),and reduced FITC-dextran leakage(P<0.05),whereas epirubicin increased vascular permeability.Conclusion Guben Yiliu No.2 effectively inhibits postoperative lung metastasis in TNBC mice.The underlying mechanism may involve regulation of the VEGF/ANG pathway,inhibition of tumor angiogenesis,and reduction of pulmonary microvascular permeability,thereby preventing the formation of the premetastatic niche.