We previously reported that hepatic stellate cells (HSCs) activated by angiotensin II (AngII) facilitate stromal fibrosis and tumor progression in intrahepatic cholangiocarcinoma (ICC). AngII has been known as a growth factor which can promote epithelial-to-mesenchymal transition (EMT) in renal epithelial cells, alveolar epithelial cells and peritoneal mesothelial cells. However, in the past, the relationship between AngII and stromal cell-derived factor-1 (SDF-1) in the microenvironment around cancer and the role of AngII on EMT of cancer cells has not been reported in detail. SDF-1 and its specific receptor, CXCR4, are now receiving attention as a mechanism of cell progression and metastasis. In this study, we examined whether activated HSCs promote tumor fibrogenesis, tumor progression and distant metastasis by mediating EMT via the AngII/AngII type 1 receptor (AT-1) and the SDF-1/CXCR4 axis. Two human ICC cell lines and a human HSC line, LI-90, express CXCR4. Significantly higher concentration of SDF-1α was released into the supernatant of LI-90 cells to which AngII had been added. SDF-1α increased the proliferative activity of HSCs and enhanced the activation of HSCs as a growth factor. Furthermore, addition of SDF-1α and AngII enhanced the increase of the migratory capability and vimentin expression, reduced E-cadherin expression, and translocated the expression of β-catenin into the nucleus and cytoplasm in ICC cells. Co-culture with HSCs also enhanced the migratory capability of ICC cells. These findings suggest that SDF-1α, released from activated HSCs and AngII, play important roles in cancer progression, tumor fibrogenesis, and migration in autocrine and paracrine fashion by mediating EMT. Our mechanistic findings may provide pivotal insights into the molecular mechanism of the AngII and SDF-1α-initiated signaling pathway that regulates fibrogenesis in cancerous stroma, tumor progression and meta-stasis of tumor cells expressing AT-1 and CXCR4.

Abstract. Intrahepatic cholangiocarcinoma (ICC) is characterized as a highly fatal tumor with poor prognosis because of its strong progression, early invasion, widespread metastasis and rich cancerous stroma. Although it is widely accepted that fibroblasts facilitate stromal fibrosis and tumor progression, the mechanisms of the interaction between cancer cells and activated fibroblasts have not been fully elucidated thus far. In this study, we demonstrate the presence of angiotensin II (AngII) in ICC tissues and explore the interaction between hepatic stellate cells (HSCs) and ICC cells as one of the sources of stromal fibrosis and tumor progression through the interaction of the AngII/AngII type 1 receptor (AT-1) axis. The concentrations of AngII in ICC tissues were significantly higher than those of HCC and normal liver. Two human ICC cell lines (HuCCT-1, CCKS-1) and a human HSC cell line (LI-90) expressed AT-1 mRNA and protein. The proliferative activity of ICC cells and HSCs to which AngII was added dose-dependently increased and AT-1 antagonist inhibited the proliferative effects. HSCs to which AngII was added showed a higher expression of ·-smooth muscle actin (·-SMA, a marker of activated HSCs and myofibroblasts), glial fibrillary acidic protein (GFAP, a specific marker of HSCs) and collagen type I than control cells. AT-1 antagonist also inhibited the activation and transformation of HSCs stimulated by AngII. These findings suggested that locally formed AngII in ICC tissues plays a role in the proliferation and activation of ICC cells and HSCs expressing AT-1 as a growth factor in autocrine and paracrine fashions. Our mechanistic findings provide the first insight into an autocrine and paracrine AngII-initiated signaling pathway that regulates ICC proliferation and fibrosis.

SummaryBackgroundThe exact sequence of events leading to ultimate hepatocellular damage following ischemia/reperfusion (I/R) is incompletely understood. In this article, we review a mechanism of organ dysfunction after hepatic I/R or immunosuppressive treatment, in addition to the potential of liver sinusoidal endothelial cell (LSEC) protection and antiplatelet treatment for the suppression of hepatocellular damage.MethodsA review of the literature, utilizing PubMed-NCBI, was used to provide information on the components necessary for the development of hepatocellular damage following I/R.ResultsIt is well-established that LSECs damage following hepatic I/R or immunosuppressive treatment followed by extravasated platelet aggregation (EPA) is the root cause of organ dysfunction in liver transplantation. We have classified three phases, from LSECs damage to organ dysfunction, utilizing the predicted pathogenic mechanism of sinusoidal obstruction syndrome. The first phase is detachment of LSECs and sinusoidal wall destruction after LSECs injury by hepatic I/R or immunosuppressive treatment. The second phase is EPA, accomplished by sinusoidal wall destruction. The various growth factors, including thromboxane A2, serotonin, transforming growth factor-beta and plasminogen activator inhibitor-1, released by EPA in the Disse’s space of zone three, induce portal hypertension and the progression of hepatic fibrosis. The third phase is organ dysfunction following portal hypertension, hepatic fibrosis, and suppressed liver regeneration through various growth factors secreted by EPA.ConclusionWe suggest that EPA in the space of Disse, initiated by LSECs damage due to hepatic I/R or immunosuppressive treatment, and activated platelets may primarily contribute to liver damage in liver transplantation. Endothelial protective therapy or antiplatelet treatment may be useful in the treatment of hepatic I/R following EPA.

Abstract. Intraperitoneal (i.p.) chemotherapy with paclitaxel (PTX) has been shown to be a promising treatment strategy for peritoneal metastasis. The present study focused on the comparative evaluation of the therapeutic efficacy of nanoparticle albumin-bound PTX (Nab-PTX) and i.

Abstract.Oxaliplatin-based chemotherapy plays a central role in the treatment of patients with colorectal liver metastasis (CRLM). This treatment, however, has been associated with hepatic sinusoidal obstruction syndrome (SOS), a clinically important adverse effect characterized by a bluish hue of the liver, splenomegaly and thrombocytopenia, resulting in liver dysfunction. The significant association between the sinusoidal endothelium and platelets has suggested that oxaliplatin-based chemotherapy affects platelets in the liver. This study compared platelet counts in patients who did and did not receive oxaliplatin-based neoadjuvant chemotherapy (NAC). The peripheral blood platelet count was significantly lower in the NAC group (n=17) compared to that in the non-NAC, or control group (n=15) (P<0.05). The spleen index was also higher in the NAC group, although the difference was not significant. However, the spleens of the patients in the NAC group were significantly enlarged following treatment (P<0.01). Immunostaining for the platelet surface marker CD42b (glycoprotein Ib), revealed more platelets in the liver in the NAC compared to the control group, particularly in the centrilobular zone III, adjacent to the hepatic central vein and in contact with hepatocytes (P<0.01). The platelets present in the spaces of Disse, referred to as extravasated platelet aggregation (EPA), secrete a number of growth factors, including transforming growth factor-β, vascular endothelial growth factor-A, plasminogen activator inhibitor-1 and thromboxane A2. In conclusion, EPA may play an important role in the development of hepatic SOS. Moreover, antiplatelet drugs may prevent the onset of SOS and hepatic injury in patients treated with oxaliplatin-based chemotherapy for CRLM.