Hepatic Angiogenesis and Fibrogenesis in the Progression of Chronic Liver Diseases

Sulfasalazine synergistically enhances the inhibitory effects of imatinib against hepatocellular carcinoma (HCC) cells by targeting NFκB, BCR/ABL, and PI3K/AKT signaling pathway-related proteins

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related fatalities worldwide. Identification of second-line therapies for patients with progressive HCC is urgently required as the use of sorafenib and/or regorafenib remains unsatisfactory. Imatinib, a small-molecule kinase inhibitor, is used to treat certain types of cancer, and nuclear factor κB (NFκB) is a positive regulator of cancer cell expansion. The combined use of tyrosine kinase and NFκB inhibitors may have potential for treating HCC. The aim of this work was to assess the potential anticarcinogenic effects of imatinib and sulfasalazine alone or in combination on the human HCC cell lines HEPG2 and Huh-7. Both drugs were shown to affect the phosphoinositide 3-kinase/protein kinase B, phosphorylated signal transducer and activator of translation (p-STAT-3), breakpoint cluster region protein/Abelson proto-oncogene and NFκB pathways. At the transcriptional level, imatinib and sulfasalazine were found to synergistically down-regulate c-MET gene expression. When compared with the activities of either medication alone, combined use of imatinib and sulfasalazine enhanced inhibition of HCC cell proliferation and extended induction of apoptosis. In summary, the presented data suggest that sulfasalazine synergistically potentiates the antitumor effects of imatinib.

Exosomes from Adipose-Derived Stem Cells (ADSCs) Overexpressing miR-21 Promote Vascularization of Endothelial Cells

In the past few years, exosomes released from adipose-derived stem cells (abbreviated as ADSCs) have shown promises to provide therapeutic benefits in the fields of regenerative medicine. miRNAs, existing in exosomes, are endogenous, small noncoding RNAs that play important roles in a variety of cellular functions and tumor development. Emerging evidences have indicated that miR-21 is one of the important miRNAs associated with tumor angiogenesis. In this study, we identified the role of exosomes from ADSCs overexpressing miR-21 in regulating/promoting vascularization of endothelial cells. Experimental data indicated an elevated miR-21 level in exosomes released by ADSCs overexpressing miR-21. In vitro matrigel angiogenesis assay showed that exosomes secreted by ADSCs overexpressing miR-21 significantly promoted the vascularization of HUVEC cells (an endothelial cell line). Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) revealed an upregulation of HIF-1α, VEGF, SDF-1, p-Akt, p-ERK1/2 and downregulation of PTEN in response to miR-21 overexpression, indicating that miR-21 enriched exosomes induced angiogenesis through Akt and ERK activation and also HIF-1α and SDF-1 expression. Our work suggests that exosomes from ADSCs that overexpressing miR-21 can potentially promote vascularization and therefore the transplantation of exosomes from their culture may be suitable for clinical effort in regenerative medicine.

Focus on histological abnormalities of intrahepatic vasculature in chronic viral hepatitis

BACKGROUND & AIMS

The histological intrahepatic microvasculature lesions have not been deeply investigated outside the setting of portal hypertension. The aim of this study was to analyse the type and the prevalence of microvasculature abnormalities and their correlation with inflammatory activity, fibrosis stage and tissue markers of fibrogenesis, angiogenesis and oxidative DNA damage in liver biopsies obtained from patients with chronic viral hepatitis.

METHODS

Seventy-four liver biopsies from untreated patients affected by hepatitis B (22 cases) and C (52 cases) were included. The presence of microvascular changes was correlated with (i) the severity of the activity and fibrosis; (ii) immunohistochemical markers of angiogenesis (CD34) and hepatic stellate cells activation (alpha-smooth muscle actin); (iii) a tissue marker of oxidative damage (8-OHdG adducts).

RESULTS

Sixty-five out of 74 biopsies (87.8%) showed vascular lesions. Portal angiomatosis was the most prevalent (62.2%) and it was associated with, on 1 side, the fibrosis stage at both univariate (P < .0001) and multivariate analysis (P = .01, OR = 9.4 [1.6-54]) and, on the other, with angiogenesis (P = .05) and hepatic stellate cells activation (P = .002). Interestingly, 36/46 cases with portal angiomatosis were at early/intermediate fibrosis stage. The hepatic stellate cells activation was also associated with the presence of aberrant periportal vessels (P = .01).

CONCLUSIONS

The histological alterations of intrahepatic microvasculature, usually seen in cirrhosis and portal hypertension, occur in chronic viral hepatitis even at early/intermediate fibrosis stages. Their correlation with angiogenesis and fibrogenesis supports a possible involvement in disease progression.