Fig. 2
ApoA1 inhibited metastasis of TNBC. (a) A stable 4T1 cell line overexpressing ApoA1, 4T1ApoA1, was generated through lentivirus infection, and the expression of ApoA1 was detected using ELISA. (b) Proliferation of 4T1ApoA1 and the parental cell line 4T1WT was determined using MTT assay. (c) and (d) Cholesterol efflux was measured using a cholesterol efflux assay kit. (e) Intracellular cholesterol levels were measured using spectrophotometric tests. BALB/c mice were orthotopically inoculated with 4T1WT and 4T1ApoA1 cells. (f) and (g) Serum was collected on day 10 to measure high-density lipoprotein (HDL) and total cholesterol (TC) levels. (h) Tumor volume in the orthotopic mouse model. (i) Survival of tumor-bearing mice (n = 7). (j) Mice were sacrificed on day 16 (n = 5) to calculate lung metastasis, and representative H&E staining images are shown. k) Micro-CT image of lung metastasis. l) and m) Tumor volume of the 4T1-luciferase orthotopic mouse model and survival of mice (n = 7). Mice were high-pressure hydrodynamically injected with an ApoA1 expression plasmid (pApoA1) via the tail vein. n) Lung metastasis of the 4T1-luciferase orthotopic mouse model, in which the primary tumor was surgically excised 10 days after tumor inoculation. o) Wound healing assays of 4T1WT or 4T1ApoA1 cells. p) Migration of 4T1 cells transfected with either ApoA1 expressing plasmid (pApoA1) or control plasmid (vehicle) was tested using wound healing assays. q) Invasion of 4T1WT or 4T1ApoA1 was evaluated by Transwell assays. Invasive cells were stained with crystal violet (left), and absorbance was measured at 590 nm after reconstitution of crystal violet (right). r) Colony formation of 4T1WT or 4T1ApoA1 cells cultured in Matrigel and imaged at 24, 48, and 72 h. *p < 0.05; **p < 0.01; ***p < 0.001