Research Paper Volume 13, Issue 5 pp 7211—7227

Follistatin-like 1 deficiency impairs T cell development to promote lung metastasis of triple negative breast cancer

FSTL1 deficiency promoted growth of metastases in lung, while rmFSTL1 had no effect on 4T1 cells. The WT and Fstl1+/- female BALB/C mice were orthotropically transplanted with murine 4T1 cells. Fourteen days after inoculation, the mice were sacrificed for study. (A) H&E stained slices of lung from WT and Fstl1+/- tumor-bearing mice (n=5). Scale bar, 200 μm. Infiltrated tumor regions were measured by Image J software. (B) The protein levels of p-CDK2 and CDK2 in the lung tissues of WT and Fstl1+/- bearing-tumor mice (n=4). Densitometric measurement of band intensity normalized to that of β-actin. (C) The expression levels of FSTL1 protein in lung of WT mice and 4T1 cells. Densitometric measurement of band intensity normalized to that of β-actin. (D) 4T1 cells were treated with different concentrations of rmFSTL1 (0, 100, 200, 500, 1000 ng/mL) for 24h, 48h, or 72h and the cell viability was assessed by CCK-8 assay. (E) The expression levels of CDK2, Caspase-3 and cleaved Caspase-3 in 4T1 cells treated with 500 ng/mL rmFSTL1 for 48h or 72h. Densitometric measurement of band intensity normalized to that of β-actin. (F) The mRNA levels of genes related to EMT in rmFSTL1 treated groups and control groups, which was normalized to that of β-actin. Data are presented as mean ± SD. Each dot in the graphs represents an individual mouse. Data in the line chart represent three sets of independent experiments. n.s., not significant; *p p

Figure 1. FSTL1 deficiency promoted growth of metastases in lung, while rmFSTL1 had no effect on 4T1 cells. The WT and Fstl1+/- female BALB/C mice were orthotropically transplanted with murine 4T1 cells. Fourteen days after inoculation, the mice were sacrificed for study. (A) H&E stained slices of lung from WT and Fstl1+/- tumor-bearing mice (n=5). Scale bar, 200 μm. Infiltrated tumor regions were measured by Image J software. (B) The protein levels of p-CDK2 and CDK2 in the lung tissues of WT and Fstl1+/- bearing-tumor mice (n=4). Densitometric measurement of band intensity normalized to that of β-actin. (C) The expression levels of FSTL1 protein in lung of WT mice and 4T1 cells. Densitometric measurement of band intensity normalized to that of β-actin. (D) 4T1 cells were treated with different concentrations of rmFSTL1 (0, 100, 200, 500, 1000 ng/mL) for 24h, 48h, or 72h and the cell viability was assessed by CCK-8 assay. (E) The expression levels of CDK2, Caspase-3 and cleaved Caspase-3 in 4T1 cells treated with 500 ng/mL rmFSTL1 for 48h or 72h. Densitometric measurement of band intensity normalized to that of β-actin. (F) The mRNA levels of genes related to EMT in rmFSTL1 treated groups and control groups, which was normalized to that of β-actin. Data are presented as mean ± SD. Each dot in the graphs represents an individual mouse. Data in the line chart represent three sets of independent experiments. n.s., not significant; *p < 0.05, **p < 0.01.