Han-Hua Dong

Combined hepatocellular cholangiocarcinoma originating from hepatic progenitor cells: immunohistochemical and double-fluorescence immunostaining evidence

Aims:  Combined hepatocellular cholangiocarcinoma (CHC) is a rare form of primary liver cancer, showing a mixture of hepatocellular and biliary features. Data suggest that most CHC arise from hepatic progenitor cells (HPCs). The aim was to investigate the origin of CHC.

Oval Cell Response Is Attenuated by Depletion of Liver Resident Macrophages in the 2-AAF/Partial Hepatectomy Rat

Background/Aims Macrophages are known to play an important role in hepatocyte mediated liver regeneration by secreting inflammatory mediators. However, there is little information available on the role of resident macrophages in oval cell mediated liver regeneration. In the present study we aimed to investigate the role of macrophages in oval cell expansion induced by 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH) in rats. Methodology/Principal Findings We depleted macrophages in the liver of 2-AAF/PH treated rats by injecting liposome encapsulated clodronate 48 hours before PH. Regeneration of remnant liver mass, as well as proliferation and differentiation of oval cells were measured. We found that macrophage-depleted rats suffered higher mortality and liver transaminase levels. We also showed that depletion of macrophages yielded a significant decrease of EPCAM and PCK positive oval cells in immunohistochemical stained liver sections 9 days after PH. Meanwhile, oval cell differentiation was also attenuated as a result of macrophage depletion, as large foci of small basophilic hepatocytes were observed by day 9 following hepatectomy in control rats whereas they were almost absent in macrophage depleted rats. Accordingly, real-time polymerase chain reaction analysis showed lower expression of albumin mRNA in macrophage depleted livers. Then we assessed whether macrophage depletion may affect hepatic production of stimulating cytokines for liver regeneration. We showed that macrophage-depletion significantly inhibited hepatic expression of tumor necrosis factor-α and interleukin-6, along with a lack of signal transducer and activator of transcription 3 phosphorylation during the early period following hepatectomy. Conclusions These data indicate that macrophages play an important role in oval cell mediated liver regeneration in the 2-AAF/PH model.

Hepatic oval cell lines generate hepatocellular carcinoma following transfection with HBx gene and treatment with aflatoxin B1 in vivo

Hepatic oval cells (HOC) are considered to be the stem cells of the liver and have been linked to the development of hepatic malignancies. Studies have demonstrated that chronic hepatitis B virus (HBV) infection and dietary aflatoxin B1 (AFB1) exposure are among the most important risk factors for the development of hepatocellular carcinoma (HCC). However, little research has been done to evaluate the role of oval cells in these two environmental factors on hepatocarcinogenesis. In this study, partial transformation of rat HOC (LE/6) were accomplished by transfected HBV x gene (HBx), and then transfected cells were implanted both intra-hepatically and subcutaneously into nude mice treated with AFB1 in vivo. We found the oval cells produced tumors (4/24 of the animals) in liver following transfection with HBx gene and treatment with AFB1. These intrahepatic tumors included HCC cells (immunopositive for HepParl, ALB, CK8 and AFP) and mesenchymal cells (immunopositive for Vimentin and SMA). Whereas mesenchymal tumors were observed at the subcutaneous tissue with a similar rate in all controls treated with cell lines (10/24 in HBx-oval cells/AFB1 group, 8/20 in HBx-oval cells/non-AFB1 group, 10/20 in non-HBx/AFB1 group; 9/20 in non-HBx/non-AFB1 group). Conversely, none of the controls developed intrahepatic tumors. These results provide an evidence that oval cells have the capacity to generate HCC through the combined effects of the HBx and AFB1 in the liver microenvironment.

The Epithelial–Mesenchymal Transition Promotes Transdifferentiation of Subcutaneously Implanted Hepatic Oval Cells Into Mesenchymal Tumor Tissue

Hepatic oval cells are thought to represent facultative hepatic epithelial stem cells in liver in which damage inhibits hepatocyte proliferation and liver regeneration. The LE/6 hepatic stem cell line was derived from the liver of male Sprague-Dawley rats fed a choline-deficient diet containing 0.1% ethionine. They are histochemically characterized by their expression of hepatocytic (hepPar1), cholangiocytic cytokeratin (CK19), hepatic progenitor cell (OV-6), and hematopoietic stem cell (c-kit) markers. In this study, we transplanted LE/6 cells by subcutaneous injection into adult female nude mice, and examined their engraftment and differentiation potential in the subcutaneous microenvironment in vivo. Our results demonstrated that following subcutaneous transplantation, differentiation of LE/6 cells into mesenchymal tumor tissue (MTT) was associated with reduced E-cadherin expression, upregulation of E-cadherin repressor molecules (Snail proteins), and increased expression of vimentin and N-cadherin, all of these events are characteristic of the epithelial-mesenchymal transition (EMT).

The niche of hepatic cancer stem cell and cancer recurrence

Currently, surgical resection is one of only a few options for treating hepatocellular carcinoma (HCC). Unfortunately, postoperative tumor recurrence remains almost inevitable despite additional radiation or chemotherapy treatment following radical resection. Clinical observations and a growing body of experimental evidence have led to speculation that there is a population of persistent hepatic cancer stem cells (HCSCs), which are difficult to completely remove surgically. HCSCs are most often in a quiescent state and thought to reside in a specific microenvironment known as a niche that provides the cues necessary for HCSCs to maintain a balance of self-renewal and differentiation. Residual HCSCs following surgery may alter their fate by invading into the blood circulation. Furthermore, it remains to be determined if hepatectomy render the postoperative niche more favorable for the survival and growth of HCSCs, and therefore the recurrence of HCC. A better understanding of the mechanisms for HCSCs self-renewal, invasion and recurrence may provide new insights into curative strategies for treating HCC.

Laparoscopic versus traditional open splenectomy for hepatocellular carcinoma with hypersplenism.

This study aimed to examine the efficacy of the laparoscopic vs. traditional open splenectomy for hepatocellular carcinoma (HCC) with hypersplenism. Between 2002 and 2013, 51 Chinese HCC patients with hypersplenism underwent either simultaneous laparoscopic splenectomy plus anticancer therapies (Lap-S&A) (n=25) or traditional open splenectomy plus anti-cancer therapies (TOS&A) (n=26). The outcomes were reviewed during and after the operation. Anti-cancer therapies for HCC included laparoscopic hepatectomy (LH) and laparoscopic microwave ablation (LMA). The results showed that there was no significant difference in the operating time between the two groups, but the blood loss and blood transfusion were less, pain intensity after surgery was weaker, the time to first bowel movement, time to the first flatus and postoperative hospital stay were shorter, and the postoperative complication rate and the readmission rate were lower in the Lap-S&A group than in the TO-S&A group. Two patients in the Lap-S&A group and one patient in the TO-S&A group died 30 days after surgery. However, no significant difference in the mortality rate was noted between the two groups. It was concluded that simultaneous Lap-S&A holds the advantages of more extensive indications, lower complication incidence and less operative expenditure than conventional open approach and it is a feasible and safe approach for HCC with hypersplenism.SummaryThis study aimed to examine the efficacy of the laparoscopic vs. traditional open splenectomy for hepatocellular carcinoma (HCC) with hypersplenism. Between 2002 and 2013, 51 Chinese HCC patients with hypersplenism underwent either simultaneous laparoscopic splenectomy plus anticancer therapies (Lap-S&A) (n=25) or traditional open splenectomy plus anti-cancer therapies (TOS&A) (n=26). The outcomes were reviewed during and after the operation. Anti-cancer therapies for HCC included laparoscopic hepatectomy (LH) and laparoscopic microwave ablation (LMA). The results showed that there was no significant difference in the operating time between the two groups, but the blood loss and blood transfusion were less, pain intensity after surgery was weaker, the time to first bowel movement, time to the first flatus and postoperative hospital stay were shorter, and the postoperative complication rate and the readmission rate were lower in the Lap-S&A group than in the TO-S&A group. Two patients in the Lap-S&A group and one patient in the TO-S&A group died 30 days after surgery. However, no significant difference in the mortality rate was noted between the two groups. It was concluded that simultaneous Lap-S&A holds the advantages of more extensive indications, lower complication incidence and less operative expenditure than conventional open approach and it is a feasible and safe approach for HCC with hypersplenism.