Induction of endogenous adult stem cells by administering soluble molecules provides an advantageous approach for tissue damage repair, which could be a clinically applicable and cost-effective alternative to transplantation of embryonic or pluripotent stem cell-derived tissues for the treatment of acute organ failures. Here, we show that HGF/Rspo1 induce liver stem cells and rescue liver dysfunction. Carbon tetrachloride treatment promotes both fibrosis and Lgr5+ liver stem cell proliferation, whereas Lgr5 knockdown worsens fibrosis. Injection of HGF in combination with Rspo1 increases the number of Lgr5+ liver stem cells and improves liver function by attenuating fibrosis. We observe Lgr5+ liver stem cells in human liver fibrosis tissues, and once they are isolated, these cells are able to form organoids, and treatment with HGF/Rspo1 promotes their expansion. We suggest that Lgr5+ liver stem cells represent a valuable target for liver damage treatment, and that HGF/Rspo1 can be used to promote liver stem cell expansion.

Abstract. Human leukocyte antigen (HLA)-F, a non-classical HLA-class I molecule, has attracted attention as an important immunosuppressive molecule in recent years, although the clinical relevance of HLA-F expression in cancer patients remains unclear. In the present study, HLA-F expression in 90 primary hepatocellular carcinoma (HCC) lesions and 55 corresponding adjacent normal liver tissues was analyzed by immunohistochemistry, and the associations between HLA-F expression and clinicopathological parameters and patient survival times were analyzed. Positive HLA-F expression was observed in 47.8% (43/90) of the HCC lesions and in 10.9% (6/55) of the normal liver tissues. HLA-F expression in HCC lesions was significantly correlated with patient gender (P=0.02), and venous or lymphatic invasion (P=0.02). Patients who were HLA-F-positive had worse survival times than those who were HLA-F-negative (P=0.04). The mean overall survival times for HLA-F-negative and -positive patients were 44.2 months [95% confidence interval (CI), 37.7-50.7] and 33.0 months (95% CI, 25.1-40.8), respectively. Multivariate analysis revealed that HLA-F was an independent prognostic factor for HCC patients with a hazard ratio of 2.1 (95% CI, 1.0-4.4). In conclusion, the present study demonstrated that HLA-F expression was associated with poor survival in HCC patients, and is correlated with tumor cell invasion and metastasis.

The expression of RNA polymerase II subunit 3 (Rpb3) was found frequent up-regulation in Hepatocellular carcinoma (HCC) tumors. Significant associations could also be drawn between increased expressions of Rpb3 and advance HCC staging and shorter disease-free survival of patients. Overexpression of Rpb3 increased HCC cell proliferation, migratory rate and tumor growth in nude mice, whereas suppression of Rpb3 using shRNA inhibited these effects. For mechanism study, we found that Rpb3 bound directly to Snail, downregulated E-cadherin, induced HCC cells epithelial-mesenchymal transition (EMT). In particular, N-terminus of Rpb3 blocked Rpb3 binding to Snail, inhibited Rpb3-high-expression HCC cells proliferation, migration, tumor growth in nude mice, and also inhibited DEN-induced liver tumorigenesis. Furthermore, N-terminus of Rpb3 did not inhibit normal liver cells or Rpb3-low-expression HCC cells proliferation. These findings suggest that N-terminus of Rpb3 selectively inhibits Rpb3-high-expression HCC cells proliferation. N-terminus of Rpb3 may be useful in treating patients diagnosed with Rpb3-high-expression HCC.