Cancer-Associated Fibroblasts from Hepatocellular Carcinoma Promote Malignant Cell Proliferation by HGF Secretion
Figure 1
Characterization and distribution of H-CAFs in vivo and in vitro.
(A) The expression of α-SMA, FAP, FSP, vimentin, fibronectin and cytokeratin in the four types of purified fibroblasts cultured for 3–10 passages was determined by immunofluorescent staining. All four fibroblast types showed high expression of the mesenchymal markers FSP, vimentin and fibronectin. NLFs, H-CAFs, PTFs and NLFs displayed high expression of α-SMA, which suggests that these fibroblasts exist in an activated state under cell culture conditions. However, another activation hallmark FAP was highly expressed in H-CAFs and PTFs but not in NSFs and NLFs. (B) Western blotting showed differences in α-SMA and FAP expression among the four fibroblasts. Consistent with the results of the immunofluorescent staining, H-CAFs, PTFs and NLFs displayed high expression of α-SMA. FAP was highly expressed in H-CAFs and PTFs but not in NSFs and NLFs. (C) The distribution of H-CAFs identified by α-SMA (+) CD31 (−) expression in each specimen from malignant, peri-tumor and normal liver regions was detected through immunohistochemistry in serial pathological sections. α-SMA expression was detected to confirm the presence of H-CAFs. In addition, CD31 expression was evaluated to exclude the presence of vascular endothelial cells, which co-express α-SMA and CD31. H-CAFs were more abundant in tumor tissue, compared with peri-tumor and normal liver tissue.