Early Detection and Characterization of Hepatocellular Carcinoma: Value of Imaging Multistep Human Hepatocarcinogenesis

Emodin, a natural anthraquinone, suppresses liver cancer in vitro and in vivo by regulating VEGFR2 and miR-34a

The pharmacokinetic (PK) and potential effects of Emodin on liver cancer were systematically evaluated in this study. Both the intragastric administration (i.g.) and hypodermic injection (i.h.) of Emodin exhibited a strong absorption (absorption rate < 1 h) and elimination capacity (t_1/2 ≈ 2 h). The tissue distribution of Emodin after i.h. was rapid and wide. The stability of Emodin in three species of liver microsomes wasrat >human> beagle dog. These PK data provided the basis for the subsequent animal experiments. In liver cancer patient tissues, the expression of vascular endothelial growth factor (VEGF)-induced signaling pathways, including phosphorylated VEGF receptor 2 (VEGFR₂), AKT, and ERK_1/2,were simultaneously elevated, but miR-34a expression was reduced and negatively correlated with SMAD₂ and SMAD₄. Emodin inhibited the expression of SMAD_2/4 in HepG2 cells by inducing the miR-34a level. Subsequently, BALB/c nude mice received a daily subcutaneous injection of HepG2 cells with or without Emodin treatment (1 mg/kg or 10 mg/kg), and Emodin inhibited tumorigenesis and reduced the mortality rate in a dose-dependent manner. In vivo experiments showed that cell proliferation, migration, and invasion were promoted by VEGF or miR-34a signal treatment but were inhibited when combined with Emodin treatment. All these results demonstrated that Emodin inhibited tumorigenesis in liver cancer by simultaneously inhibiting the VEGFR₂-AKT-ERK_1/2signaling pathway and promoting a miR-34a-mediated signaling pathway.

Antiangiogenic and Antitumor Activities of Aflibercept, a Soluble VEGF Receptor-1 and -2, in a Mouse Model of Hepatocellular Carcinoma

BACKGROUND & AIM: Aflibercept known as ziv-aflibercept in the United States is a soluble decoy receptor of both vascular endothelial growth factor (VEGF) receptor-1 and -2 known to inhibit the binding of VEGF and placental growth factor (PlGF) to VEGF receptor-1 and -2. Here, we analyzed the mechanisms of the antitumor effects of aflibercept in mouse hepatoma models. METHODS: In in vitro studies, we determined the effects of aflibercept on human umbilical vein cell (HUVEC) proliferation and bone marrow (BM) cell differentiation to endothelial progenitor cells (EPCs). In in vivo experiments, aflibercept was injected intraperitoneally in hepatoma cell tumor-bearing mice, and its inhibitory effects on tumor growth and BM cell migration to tumor tissues were evaluated. RESULTS: Aflibercept suppressed phosphorylation of VEGF receptor-1 and -2 in HUVEC and dose-dependently inhibited VEGF-induced HUVEC proliferation. It suppressed the differentiation of BM cells to EPCs and migration of BM cells to tumor tissues. It also suppressed tumor growth and prolonged survival time of tumor-bearing mice without side effects. In tumor tissues, aflibercept upregulated the expression of hypoxia inducible factor1-α, VEGF, PlGF, fibroblast growth factor-2, platelet derived growth factor-BB, and transforming growth factor-α and reduced microvascular density. It also reduced sinusoidal density in noncancerous liver tissues. CONCLUSIONS: Our results demonstrated potent antitumor activity for aflibercept in a mouse model of hepatocellular carcinoma. These effects were mediated through inhibition of neovascularization, caused by inhibition of endothelial cell proliferation, EPC differentiation, and BM cell migration to tumor tissues.

Vandetanib, an inhibitor of VEGF receptor-2 and EGF receptor, suppresses tumor development and improves prognosis of liver cancer in mice

PURPOSE

VEGF, EGF, and TGF-α are expressed in hepatocellular carcinomas (HCC) and play a role in its growth. Vandetanib, a multikinase inhibitor, suppresses the phosphorylation of VEGF receptor 2 (VEGFR-2) and EGF receptor (EGFR). The aim of this study was to clarify the antitumor effect of vandetanib in mouse HCCs.

EXPERIMENTAL DESIGN

We evaluated the effects of vandetanib on proliferation of human umbilical vein endothelial cells (HUVEC) and three hepatoma cell lines, as well as the phosphorylation of VEGFR-2 and EGFR in these cells. Mice were implanted with hepatoma cells subcutaneously or orthotopically in the liver and treated with 50 or 75 mg/kg vandetanib. We analyzed the effects of treatment on tumor cell proliferation and apoptosis, vessel density, phosphorylation of VEGFR-2 and EGFR, and production of VEGF, TGF-α, and EGF in tumor tissues. Adverse events on vandetanib administration were also investigated.

RESULTS

Vandetanib suppressed phosphorylation of VEGFR-2 in HUVECs and EGFR in hepatoma cells and inhibited cell proliferation. In tumor-bearing mice, vandetanib suppressed phosphorylation of VEGFR-2 and EGFR in tumor tissues, significantly reduced tumor vessel density, enhanced tumor cell apoptosis, suppressed tumor growth, improved survival, reduced number of intrahepatic metastases, and upregulated VEGF, TGF-α, and EGF in tumor tissues. Treatment with vandetanib was not associated with serious adverse events, including alanine aminotransferase abnormality, bone marrow suppression, or body weight loss.

CONCLUSIONS

The antitumor effects of vandetanib in mice suggest that it is a potentially suitable and safe chemotherapeutic agent for HCCs.

Detection Of Focal Liver Lesions In Cirrhotic Liver Using Contrast-Enhanced Ultrasound

Patients with liver cirrhosis are at increased risk of hepatocellular carcinoma (HCC). Conventional or baseline ultrasound (BUS) is often used as the first-line tool for HCC surveillance or detection, but the accuracy of BUS in HCC detection or differentiation from other focal liver lesions (FLLs) is limited. Contrast-enhanced ultrasound (CEUS) represents a recent revolution in the field of ultrasonography and it has become increasingly important in the detection and evaluation of FLLs. In CEUS, HCC typically exhibits arterial hyper-enhancement and portal-venous washout represented by hypo-enhanced lesions in the portal venous and late phases. The detection rate of HCC was significantly higher with CEUS compared with BUS. Even regenerative or some dysplastic nodules may exhibit arterial hyper-enhancement as they are differentiated from HCC by its iso-enhancing pattern in portal and late phases. The contrast-enhancement patterns of other different types of benign and malignant FLLs, as well as their detection rates with CEUS, were also discussed.

Role of B-mode ultrasound screening in detection of local tumor recurrence in the first year after radiofrequency ablation in the liver

BACKGROUND

Ultrasound is known to be useful in imaging radiofrequency ablation (RFA) lesions intra- and postoperatively. The presented study intends to prove the value of ultrasound examination as a means of screening RFA-treated patients for local tumor recurrence.

PATIENTS AND METHODS

During a period of 47 months, 91 RFA treatments were performed in 61 patients in a single institution. Indications for RFA were hepatocellular carcinoma (74%), colorectal metastases (18%), recurrent cholangiocellular carcinoma (5%) and one neuroendocrine tumor metastasis as well as one metastasis of pancreatic cancer (1.5% each). RFA was only considered in non-resectable liver cancer. All applications were conducted under sonographic guidance following preoperative evaluation. Postoperative screening included sonographic examinations at intervals of 3, 6 and 12 months postoperatively, and further annual follow-up examinations. Mean follow-up period was 11.8 months.

RESULTS

Within the first 12 months after treatment, the lesions become more and more inhomogenous with mixed echogeneity. Occasionally, this evolves as a misleading finding, mimicking early tumor recurrence. To clarify suspicious cases (31%), magnetic resonance imaging (20%) or computed tomography (10%) was engaged. Ultrasound led to the detection of local tumor recurrence in 78% of recurrent HCC (13 patients), but only in 67% of metastatic diseases (3 patients). Overall local recurrence rate was 18%.

CONCLUSION

Ultrasound screening as a follow-up of primary hepatic malignancies is, due to its sensitivity, capable of detecting early local recurrence despite its low specifity. Appropriate application of particular criteria of local recurrence allows B-mode ultrasound to play a major role in screening RFA-treated patients.

Proposal of progression model for intrahepatic cholangiocarcinoma: clinicopathologic differences between hilar type and peripheral type

It is important to clarify the histologic progression of intrahepatic cholangiocarcinoma (ICC) in consideration of its origin from the intrahepatic large or small biliary ducts. On the basis of the gross and histologic assessment, we classified 87 cases of ICC smaller than 5 cm in diameter into hilar type (H-ICC, n=38) or peripheral type (P-ICC, n=49) to compare their clinical and histologic features. Biliary dysplasia was observed in 65.8% (25/38) of H-ICC cases, whereas hepatitis virus infection and liver cirrhosis were associated with 46.7% (21/45) and 28.6% (14/49) of P-ICC, respectively. The frequency of perineural invasion, lymph node metastasis, and extrahepatic recurrence of H-ICC was significantly higher than that of P-ICC (P<0.0001, 0.0106, and 0.0279, respectively). H-ICC cases showed frequent vascular invasion and intrahepatic metastasis even with small tumor size, compared with P-ICC cases. H-ICC showed large duct involvement within the tumor, and in the cases of large tumor size, intraductal spread was detected in the tumor periphery. P-ICC of small size contained preserved architecture of the portal tracts. The survival of patients with H-ICC was worse than that of patients with P-ICC (P=0.0121). The independent and best prognostic factor by multivariate analysis was intrahepatic metastasis for H-ICC and lymph node metastasis for P-ICC. Our results suggest that ICCs derived from a different level of biliary ducts were related to different premalignant conditions and different tumor progression. Some ICCs arising from the large biliary duct are likely to exhibit an aggressive course even in cases of small tumor size. The recognition of the above events induces the proper therapy.

Enhancement patterns and signal-intensity characteristics of small hepatocellular carcinoma in cirrhosis: pathologic basis and diagnostic challenges

Recent pathologic studies of hepatic resection and transplantation specimens have elucidated the morphologic features of the precancerous lesions and small hepatocellular carcinomas (HCCs) arising in cirrhotic livers. Small HCCs measuring less than 2 cm in diameter are of two types: vaguely nodular, well-differentiated tumors, also known as "early" HCCs, and distinctly nodular tumors, with histologic features of "classic" HCC. The precancerous lesions include dysplastic foci and dysplastic nodules. "Classic" small HCCs are supplied by nontriadal arteries, whereas early HCCs and dysplastic nodules may receive blood supply from both portal tracts and nontriadal arteries. The similarities in blood supply of these three types of nodular lesions result in significant overlap of findings on dynamic imaging. Nevertheless, small HCCs sometimes display characteristic radiologic features, such as "nodule-in-nodule" configuration and "corona enhancement" pattern. Moreover, various histologic features of these nodular lesions may also be related to a variety of signal intensities and attenuation coefficients, while the presence of cirrhosis is known to limit the sensitivity and specificity of any imaging modality, due to liver inhomogeneity. Because of these reasons, imaging findings of nodular lesions in cirrhotic livers are often inconclusive, emphasizing the need for a better understanding of these imaging features.

The emerging importance of chronic hepatitis C infection in Asian Americans

OBJECTIVES

To study the demographics, epidemiology, and natural history of chronic hepatitis C in Asian Americans.

METHODS

This retrospective survey describes 260 Asian Americans with chronic hepatitis C referred to one tertiary center.

RESULTS

Ninety-two percent of patients were born in Asia. Fifty-one percent reported a history of unsafe therapeutic injections, which was a risk factor only in those with exposure outside the United States (p < 0.0001). A history of transfusion was reported in 41% of patients and was more frequent in those with exposure within the Unites States (p < 0.0001). Only 3.8% reported a history of intravenous drug abuse, which was more frequent in those with exposure within the United States (p < 0.0001). Hepatitis C genotype 1 was detected in 64.2% of patients, genotype 2 in 18.3%, and genotype 6 in 11.3%. Genotype 1 had a significantly lower sustained virologic response rate (32.8%) to interferon treatment, compared with genotype 2 (77.8%) or 6 (69.2%). During a mean follow-up of 6 yr, 26 patients developed hepatocellular carcinoma (HCC). Logistic regression model revealed fibrosis stage 4 (odds ratio [OR] 8.87, 95% confidence interval [CI] 2.97-26.48, p < 0.0001), age at presentation (55 vs 35 yr--OR 3.45, 95% CI 1.22-9.75, p= 0.0194), and baseline albumin level (3.0 vs 4.0 mg/dL--OR 3.47, 95% CI 1.02-11.76, p= 0.0464) were independent predictive factors for HCC development.

CONCLUSIONS

Asian Americans with a history of unsafe therapeutic injections must be screened for chronic hepatitis C. Antiviral treatment should be initiated prior to development of cirrhosis. Surveillance for HCC must be routinely performed in cirrhosis patients.