h-α-SMA was more strongly expressed than mouse α-SMA, as measured by real-time polymerase chain reaction (PCR), and in drug-treated animals the human isoform of α-SMA but not the murine isoform was down-regulated, suggesting that injected PTFs were still present and functionally active at the end of the experiment, and also that the presence of host/resident myofibroblasts did not significantly affect results (Fig. 6D). In conclusion, we demonstrated that LPA secreted by HCC cells recruits

and activates PTFs, orchestrating their differentiation FK866 to a CAF-like myofibroblastic phenotype which, in turn, accelerates HCC progression. Finally, we aimed to validate these findings in HCC patients. We therefore analyzed LPA serum levels in 60 patients with HCC (30 patients with and 30 without metastases), and in 50 patients with liver cirrhosis. We found that LPA serum levels were higher in HCC compared with liver cirrhosis patients (P < 0.05). Among HCC patients, Dabrafenib LPA serum levels were significantly (P < 0.05) higher in those with metastasis compared with those

without (Fig. 6A). Patients with higher (P < 0.001) serum levels of LPA also have larger HCC tumors (>4 cm) and shorter survival compared with those with lower LPA serum concentrations (Fig. 6B,C). To validate our LPA data in HCC patients, publicly accessible microarray data were analyzed for a correlation between ATX and clinical outcome in HCC patients. ATX expression was significantly increased in HCC patients with more advanced disease, in particular in those with metastatic invasion (P < 0.001) (Fig. 6D),13 and was more strongly expressed in tumoral compared with paired nontumoral tissues (Fig. 6E,F) . In addition, we compared the expression of ATX and LPA receptors in epithelial and stromal components of the same HCC tissues microdissected

using the laser capture microscope technique check details (Fig. 7A,B). We found similar expression levels of ATX in both the epithelial and the stromal component of HCC. However, LPA receptors were essentially expressed in the stromal rather than the epithelial component, indicating the stroma as the main target of the LPA paracrine loop (Fig. 7C). Finally, the ACTA2 gene was significantly expressed in tumoral compared with paired nontumoral tissues (Fig. 7D). This is consistent with publicly accessible microarray data published by Wang (Fig. 7E). Taken together, these data show that the stromal component represents the main target of LPA in patients with HCC, and that α-SMA–positive cells are predominant within the tumor stroma, as shown by the increased expression of the ACTA2 gene.