Zhengfeng Yin

BACKGROUND: Cancer stem cells (CSCs) are regarded as the cause of tumor formation and recurrence. The isolation and identification of CSCs could help to develop novel therapeutic strategies specifically targeting CSCs. METHODS: Human hepatoma cell lines were plated in stem cell conditioned culture system allowed for sphere forming. To evaluate the stemness characteristics of spheres, the self-renewal, proliferation, chemoresistance, tumorigenicity of the PLC/PRF/5 sphere-forming cells, and the expression levels of stem cell related proteins in the PLC/PRF/5 sphere-forming cells were assessed, comparing with the parental cells. The stem cell RT-PCR array was performed to further explore the biological properties of liver CSCs. RESULTS: The PLC/PRF/5, MHCC97H and HepG2 cells could form clonal nonadherent 3-D spheres and be serially passaged. The PLC/PRF/5 sphere-forming cells possessed a key criteria that define CSCs: persistent self-renewal, extensive proliferation, drug resistance, overexpression of liver CSCs related proteins (Oct3/4, OV6, EpCAM, CD133 and CD44). Even 500 sphere-forming cells were able to form tumors in NOD/SCID mice, and the tumor initiating capability was not decreased when spheres were passaged. Besides, downstream proteins DTX1 and Ep300 of the CSL (CBF1 in humans, Suppressor of hairless in Drosophila and LAG1 in C. elegans) -independent Notch signaling pathway were highly expressed in the spheres, and a gamma-secretase inhibitor MRK003 could significantly inhibit the sphere formation ability. CONCLUSIONS: Nonadherent tumor spheres from hepatoma cell lines cultured in stem cell conditioned medium possess liver CSC properties, and the CSL-independent Notch signaling pathway may play a role in liver CSCs.

BACKGROUND: There is no clear consensus on the better therapy [radiofrequency ablation (RFA) versus hepatic resection (HR)] for small hepatocellular carcinoma (HCC) eligible for surgical treatments. This study is a meta-analysis of the available evidence. METHODS: Systematic review and meta-analysis of trials comparing RFA with HR for small HCC published from 1997 to 2009 in PubMed and Medline. Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model. RESULTS: One randomized controlled trial, and 9 nonrandomized controlled trials studies were included in this analysis. These studies included a total of 1411 patients: 744 treated with RFA and 667 treated with HR. The overall survival was significantly higher in patients treated with HR than in those treated with RFA at 3 years (OR: 0.56, 95% CI: 0.44-0.71), and at 5 year (OR: 0.60, 95% CI: 0.36-1.01). RFA has a higher rates of local intrahepatic recurrence compared to HR (OR: 4.50, 95% CI: 2.45-8.27). In the HR group the 1, 3, and 5 years disease -free survival rates were significantly better than in the HR-treated patients (respectively: OR: 0.54, 95% CI: 0.35-0.84; OR: 0.44, 95% CI: 0.28-0.68; OR: 0.64, 95% CI: 0.42-0.99). The postoperative morbidity was higher with HR (OR: 0.29, 95% CI: 0.13-0.65), but no significant differences were found concerning mortality. For tumors <or= 3 cm HR did not differ significantly from RFA for survival, as reported in three NRCTs . CONCLUSIONS: HR was superior to RFA in the treatment of patients with small HCC eligible for surgical treatments, particularly for tumors > 3 cm. However, the findings have to be carefully interpreted due to the lower level of evidence.

AIM: To carry out a hospital-based case-control study to investigate risk factors for intrahepatic cholangiocarcinoma (ICC) in China. METHODS: A total of 312 ICC cases and 438 matched controls were included in the study. The presence of diabetes mellitus, hypertension, hepatolithiasis, primary sclerosing cholangitis, liver fluke infection (Clonorchis sinensis), was investigated through clinical records. Blood from all participants was tested for hepatitis B surface antigen (HBsAg) and anti-HCV antibodies. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression. RESULTS: Compared with controls, ICC patients had a higher prevalence of HBsAg seropositivity (48.4% vs 9.6%, P<0.000), and hepatolithiasis (5.4% vs 1.1%, P=0.001). By multivariate analysis, the significant risk factors for development of ICC were HBsAg seropositivity (adjusted OR, 8.876, 95% CI, 5.973-13.192), and hepatolithiasis (adjusted OR, 5.765, 95% CI, 1.972-16.851). The prevalence of anti-HCV seropositivity, diabetes mellitus, hypertension, cigarette smoking, and alcohol consumption were not significantly different between cases and controls. CONCLUSION: These findings suggest that HBV infection and hepatolithiasis are strong risk factors for development of ICC in China.

PURPOSE: To establish a sensitive and specific isolation and enumeration system for circulating tumor cells (CTC) in patients with hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: HCC cells were bound by biotinylated asialofetuin, a ligand of asialoglycoprotein receptor, and subsequently magnetically labeled by antibiotin antibody-coated magnetic beads, followed by magnetic separation. Isolated HCC cells were identified by immunofluorescence staining using Hep Par 1 antibody. The system was used to detect CTCs in 5 mL blood. Blood samples spiked with Hep3B cells (ranging from 10 to 810 cells) were used to determine recovery and sensitivity. Prevalence of CTCs was examined in samples from HCC patients, healthy volunteers, and patients with benign liver diseases or non-HCC cancers. CTC samples were also analyzed by FISH. RESULTS: The average recovery was 61% or more at each spiking level. No healthy, benign liver disease or non-HCC cancer subjects had CTCs detected. CTCs were identified in 69 of 85 (81%) HCC patients, with an average of 19 ± 24 CTCs per 5 mL. Both the positivity rate and the number of CTCs were significantly correlated with tumor size, portal vein tumor thrombus, differentiation status, and the disease extent as classified by the TNM (tumor-node-metastasis) classification and the Milan criteria. HER-2 gene amplification and TP53 gene deletion were detected in CTCs. CONCLUSION: Our system provides a new tool allowing for highly sensitive and specific detection and genetic analysis of CTCs in HCC patients. It is likely clinically useful in diagnosis and monitoring of HCC and may have a role in clinical decision making.

BACKGROUND: This study aimed to assess the efficacy and safety of repeat hepatectomy for recurrent hepatocellular carcinoma (HCC). METHODS: Thirty-seven patients who underwent a curative repeat hepatectomy in our hospital were retrospectively studied. An extensive database literature search was performed to obtain for all relevant studies. RESULTS: In our series, there were no perioperative deaths during repeat hepatectomy for recurrent HCC. Patients survival after repeat hepatectomy were similar to 429 patients undergoing initial hepatectomy. A computerized search of the Medline and PubMed databases found 29 retrospective studies providing relevant data in 1149 patients were included for appraisal and data extraction. After the repeat hepatectomy, postoperative morbidity ranged from 6.2% to 68.2% with a median per cohort of 23.5 per cent. There were 7 perioperative deaths (0.7 per cent of 993 for whom mortality data were provided). The overall median survival ranged from 21 to 61.5 months, with 1-, 3-, and 5-year survival of 69.0% to 100%, 21.0% to 87.0%, and 25.0% to 87.0%, respectively. CONCLUSIONS: Repeat hepatectomy can be performed safely and is associated with long-term survival in a subset of patients with recurrent HCC. However, the findings have to be carefully interpreted due to the lower level of evidence. A randomized controlled study is needed to compare repeat hepatectomy and other modalities for recurrent HCC.