Expression of Ep-CAM in normal, regenerating, metaplastic, and neoplastic liver

Trial Watch: Adoptively transferred cells for anticancer immunotherapy

Immunotherapies aimed at strengthening immune effector responses against malignant cells are growing at exponential rates. Alongside, the impressive benefits obtained by patients with advanced melanoma who received adoptively transferred tumor-infiltrating lymphocytes (TILs) have encouraged the scientific community to pursue adoptive cell transfer (ACT)-based immunotherapy. ACT involves autologous or allogenic effector lymphocytes that are generally obtained from the peripheral blood or resected tumors, expanded and activated ex vivo, and administered to lymphodepleted patients. ACT may be optionally associated with chemo- and/or immunotherapeutics, with the overall aim of enhancing the proliferation, persistence and functionality of infused cells, as well as to ensure their evolution in an immunological permissive local and systemic microenvironment. In addition, isolated lymphocytes can be genetically engineered to endow them with the ability to target a specific tumor-associated antigen (TAA), to increase their lifespan, and/or to reduce their potential toxicity. The infusion of chimeric antigen receptor (CAR)-expressing cytotoxic T lymphocytes redirected against CD19 has shown promising clinical efficacy in patients with B-cell malignancies. Accordingly, the US Food and Drug Administration (FDA) has recently granted 'breakthrough therapy' designation to a CAR-based T-cell therapy (CTL019) for patients with B-cell malignancies. Considerable efforts are now being devoted to the development of efficient ACT-based immunotherapies for non-hematological neoplasms. In this Trial Watch, we summarize recent clinical advances on the use of ACT for oncological indications.

Microfluidic chip for isolation of viable circulating tumor cells of hepatocellular carcinoma for their culture and drug sensitivity assay

Circulating tumor cells (CTCs) have been proposed to be an active source of metastasis or recurrence of hepatocellular carcinoma (HCC). The enumeration and characterization of CTCs has important clinical significance in recurrence prediction and treatment monitoring in HCC patients. We previously developed a unique method to separate HCC CTCs based on the interaction of the asialoglycoprotein receptor (ASGPR) expressed on their membranes with its ligand. The current study applied the ligand-receptor binding assay to a CTC-chip in a microfluidic device. Efficient capture of HCC CTCs originates from the small dimensions of microfluidic channels and enhanced local topographic interactions between the microfluidic channel and extracellular extensions. With the optimized conditions, a capture yield reached > 85% for artificial CTC blood samples. Clinical utility of the system was further validated. CTCs were detected in all the examined 36 patients with HCC, with an average of 14 ± 10/2 mL. On the contrary, no CTCs were detected in healthy, benign liver disease or non-HCC cancer subjects. The current study also successfully demonstrated that the captured CTCs on our CTC-chip were readily released with ethylene diamine tetraacetic acid (EDTA); released CTCs remained alive and could be expanded to form a spheroid-like structure in a 3-dimensional cell culture assay; furthermore, sensitivity of released CTCs to chemotherapeutic agents (sorafenib or oxaliplatin) could be effectively tested utilizing this culture assay. In conclusion, the methodologies presented here offer great promise for accurate enumeration and easy release of captured CTCs, and released CTCs could be cultured for further functional studies.

Detection of circulating tumor cells in patients with hepatocellular carcinoma using an improved asialoglycoprotein receptor-based separation method

AIM: To introduce a novel magnetic cell separation system which allows for immunomorphological identification and enumeration of circulating tumor cells (CTCs) in patients with hepatocellular carcinoma (HCC).

METHODS: The asialoglycoprotein receptor (ASGPR) is a transmembrane protein expressed exclusively on the surface of hepatocytes. We have recently developed a sensitive and specific system mediated by the interaction of the ASGPR with its ligand to magnetically separate CTCs in HCC patients. In the system, HCC cells were bound by biotinylated asialofetuin, an ASGPR ligand, and subsequently labeled by anti-biotin antibody-coated magnetic beads, followed by magnetic separation. The separated HCC cells were then identified by immunofluorescence staining using the hepatocyte-specific antibody Hep Par 1. In this study, we used EDTA instead of heparin for anticoagulation because heparin could cause the presence of gels in cell suspension, which affected the passage of cells through the separation column and reduced the separation efficiency. The recovery, specificity and sensitivity of the HCC CTC separation and detection system were determined by performing Hep3B cell spiking experiments.

RESULTS: Calcium chelating agent EDTA was used for anticoagulation instead of heparin in some steps of the original method and gel phenomenon no longer appeared in the cell suspension. The cell spiking experiments showed that when there were 10, 30, 90, 270 and 810 Hep3B cells spiked into five milliliters of peripheral blood from healthy volunteers, the average recovery was ≥ 70% at each spiking level and the recovery of the modified method was higher than that of the original method (P < 0.05).

CONCLUSION: We have developed a new tool that allows for highly sensitive and specific separation and detection of CTCs in HCC patients. It may be clinically useful for diagnosis and monitoring of HCC. The cell spiking experiments showed that the recovery of the modified method was higher than that of the original method.

Monitoring of the generation of circulating tumor cells in central venous blood of patients undergoing right hepatectomy using anterior liver hanging maneuver

AIM: To monitor the generation of circulating tumor cells in central venous blood of patients undergoing right hepatectomy using anterior liver hanging (ALH) maneuver.

METHODS: From January 2008 to June 2011, 40 patients undergoing right hepatectomy were randomly allocated to ALH and conventional approach (CA) groups. Blood samples were collected from all patients through a central venous catheter, just before skin incision, just before parenchymal transection (after hilar dissection in the ALH group and after mobilization of the liver in the CA group), and after delivery of the tumor. All samples were detected for CTCs using an asialoglycoprotein receptor-based isolation strategy. The proportions of CTC-positive patients at various stages of surgery were compared between the two groups.

RESULTS: The proportion of CTC-positive patients showed no significant difference before surgery between the two groups (2/18 vs 1/19, P > 0.05) but was significantly lower in the ALH group than in the CA group before parenchymal transection and at the end of surgery after delivery of the tumor (20% vs 55%, 40% vs 80%, P = 0.022, 0.010).

CONCLUSION: Right hepatectomy using anterior liver hanging maneuver can reduce intraoperative blood-borne spread of tumor cells compared with the conventional method.

Hepatic progenitor cell surface markers and biological function

Hepatic progenitor cells have the bipotential capable of differentiation into mature hepatocytes and biliary epithelial cells when hepatocyte proliferation is inhibited and liver regeneration compromised. This review focuses on the surface markers and biological function of hepatic progenitor cells and the existed questions in this field are also discussed.