Liver-Directed Treatment Modalities for Primary and Secondary Hepatic Tumors

The combination of Biochanin A and SB590885 potentiates the inhibition of tumour progression in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most aggressive and frequently diagnosed malignancy of the liver. Despite aggressive therapy, life expectancy of many patients in these cases is extended by only a few months. Hepatocellular carcinoma (HCC) has a particularly poor prognosis and would greatly benefit from more effective therapies.

Methods

The CCK-8 assay and colony formation assays were used to test the cell proliferation and viability. The effects of combination Biochanin A and SB590885 on apoptosis and cell cycle arrest of HCC cells were analysed by flow cytometry. The expression of ERK MAPK and PI3K/AKT/mTOR signalling as well as apoptosis and cell cycle-related proteins in HCC cells were tested by western blotting. The HCC cell xenograft model was established to test the tumor proliferation. Serum and plasma were tested for liver and kidney safety markers (ALP, ALT, AST, total bilirubin, creatinine, urea nitrogen) by using SpectraMax i3X.

Results

The combination of natural product Biochanin A with the BRAF inhibitor SB590885 synergistically suppressed proliferation, and promoted cell cycle arrest and apoptosis in vitro. Furthermore, we demonstrated that the combination of Biochanin A and SB590885 led to increased impairment of proliferation and HCC tumour inhibition through disrupting of the ERK MAPK and the PI3K/AKT pathways in vitro. The volumes tumors and the weights of tumours were significantly reduced by the combination treatment compared to the control or single treatments in vivo. In addition, we found that there was no significant hepatorenal toxicity with the drug combination, as indicated by the hepatorenal toxicity test.

Conclusion

The results identify an effective combination therapy for the most aggressive form of HCC and provide the possibility of therapeutic improvement for patients with advanced HCC.

Identification and functional analysis of a core gene module associated with hepatitis C virus-induced human hepatocellular carcinoma progression

Hepatitis C virus (HCV)-induced human hepatocellular carcinoma (HCC) progression may be due to a complex multi-step processes. The developmental mechanism of these processes is worth investigating for the prevention, diagnosis and therapy of HCC. The aim of the present study was to investigate the molecular mechanism underlying the progression of HCV-induced hepatocarcinogenesis. First, the dynamic gene module, consisting of key genes associated with progression between the normal stage and HCC, was identified using the Weighted Gene Co-expression Network Analysis tool from R language. By defining those genes in the module as seeds, the change of co-expression in differentially expressed gene sets in two consecutive stages of pathological progression was examined. Finally, interaction pairs of HCV viral proteins and their directly targeted proteins in the identified module were extracted from the literature and a comprehensive interaction dataset from yeast two-hybrid experiments. By combining the interactions between HCV and their targets, and protein-protein interactions in the Search Tool for the Retrieval of Interacting Genes database (STRING), the HCV-key genes interaction network was constructed and visualized using Cytoscape software 3.2. As a result, a module containing 44 key genes was identified to be associated with HCC progression, due to the dynamic features and functions of those genes in the module. Several important differentially co-expressed gene pairs were identified between non-HCC and HCC stages. In the key genes, cyclin dependent kinase 1 (CDK1), NDC80, cyclin A2 (CCNA2) and rac GTPase activating protein 1 (RACGAP1) were shown to be targeted by the HCV nonstructural proteins NS5A, NS3 and NS5B, respectively. The four genes perform an intermediary role between the HCV viral proteins and the dysfunctional module in the HCV key genes interaction network. These findings provided valuable information for understanding the mechanism of HCV-induced HCC progression and for seeking drug targets for the therapy and prevention of HCC.

14-3-3ζ promotes hepatocellular carcinoma venous metastasis by modulating hypoxia-inducible factor-1α

Portal vein tumor thrombus (PVTT) is a type of intrahepatic metastasis arising from hepatocellular carcinoma (HCC) and is highly correlated with a poor prognosis. Hypoxia is common in solider tumors, including HCC, where it alters the behavior of HCC cells. We asked whether and how hypoxia contributes to PVTT formation. We demonstrated that increased intratumoral hypoxia is strongly associated with PVTT formation in HCC. We also showed that 14-3-3ζ is induced by hypoxia in HCC cells and correlates with PVTT formation in clinical HCC samples. In addition, 14-3-3ζ up-regulates HIF-1α expression by recruiting HDAC4, which prevents HIF-1α acetylation, thereby stabilizing the protein. Under hypoxic conditions in vitro, 14-3-3ζ knockdown inhibits hypoxia-induced HCC invasion by the HIF-1α/EMT pathway. Blockade of 14-3-3ζ in HCC cells reduces PVTT formation and distant lung metastasis in vivo. Moreover, a combination of 14-3-3ζ and HIF-1α expression is more prognostic for HCC patients than either protein alone. These results suggest that the hypoxia/14-3-3ζ/HIF-1α pathway plays an important role in PVTT formation and HCC metastasis.

Detecting abnormal methylation of tumor suppressor genes GSTP1, P16, RIZ1, and RASSF1A in hepatocellular carcinoma and its clinical significance

Hepatocellular carcinoma (HCC) has a high rate of mortality. Further studies into epigenetic changes in HCC, particularly the abnormal methylation of tumor suppressor genes (TSGs), are required, since these changes may provide novel biomarkers for early screening and diagnosis of HCC. By using methylation-specific polymerase chain reaction (MSP), the present study detected the methylation status in the promoter region of 4 candidate TSGs, GSTP1, P16, RIZ1, and RASSF1A, respectively, in 35 paired HCC and tumor-adjacent liver tissues in addition to 20 normal liver tissues. Their effect on the initiation and progression of HCC was also investigated by analyzing the clinicopathological data. The results of the present study revealed that the methylation level of RIZ1 and GSTP1 genes in HCC was significantly increased compared with that in the adjacent tissues (P<0.01) and the normal liver tissues (P<0.01). The methylation frequency of P16 and RASSF1A genes was not significantly increased compared with that observed in the adjacent tissues (P>0.05) but was significantly increased compared with the normal tissues (P<0.01). In HCC tissues, the methylation frequency of the GSTP1 gene in tumors with capsular invasion was significantly increased compared with that in tumors without capsular invasion (P<0.05). The methylation frequency of P16 gene in hepatitis B surface antigen (HbsAg)-positive HCC patients was significantly increased compared with that in HbsAg-negative patients (P<0.05). The methylation status of RIZ1 and RASSF1A genes was not significantly correlated with the clinicopathological data (P>0.05). Previous studies have demonstrated that the methylation status of RIZ1 and GSTP1 genes is HCC-specific, and thus may be used as a biomarker to assist the clinical diagnosis of HCC. While the methylation of GSTP1 gene promoter may associate with the invasiveness of HCC, chronic hepatitis B virus infection may be the cause of methylation-induced P16 inactivation.

Experimental study on enhancement of the metastatic potential of portal vein tumor thrombus-originated hepatocellular carcinoma cells using portal vein serum

OBJECTIVE

Portal vein metastasis of hepatocellular carcinoma (HCC) results in a poor prognosis and seriously affects the survival rate of patients. The mechanism underlying the formation of portal vein tumor thrombus (PVTT) is complex and is not yet fully understood. This study was conducted to investigate the impact of portal vein blood on the proliferation, metastasis, invasion and apoptosis of PVTT cells and to explore its possible mechanisms, which was expected to lay a foundation for ascertaining the mechanism underlying the portal vein metastasis of HCC.

METHODS

Peripheral blood and portal vein blood were collected from patients with HCC, and the sera from these two sources were used to culture the PVTT-originated HCC cell line CSQT-2. The cells were collected after 24 h, and flow cytometry was performed to detect cell proliferation, cell cycle stages and apoptosis. Transwell migration and invasion assays were applied to detect the metastasis and invasion of the cells in each group. The changes in the expression of MMP-2 and MMP-9 in cells were detected via Western blotting. The contents of IL-12, IFN-γ, IL-1β, IL-2 and TNF-α in the two groups of sera were quantified using corresponding kits.

RESULTS

Compared with the group of cells cultured with peripheral serum, the cells cultured with portal vein serum showed significantly lower apoptosis (P<0.01), significantly enhanced cell metastasis and invasion (P<0.01), whereas cell proliferation and the stages of the cell cycle did not differ significantly (P>0.05). A significantly increased expression level of MMP-2 has been observed in tumor cells treated portal vein serum. In addition, compared with peripheral serum, the content of IL-12 was significantly decreased in portal vein serum (P<0.05), while the contents of IFN-γ, IL-1β, IL-2, and TNF-α did not differ significantly (P>0.05).

CONCLUSIONS

Portal vein serum from HCC patients could inhibit the apoptosis of PVTT-originated HCC cells and promote cell metastasis and invasion. This effect may be related to the lower level of IL-12 in portal vein serum.

Targeting different angiogenic pathways with combination of curcumin, leflunomide and perindopril inhibits diethylnitrosamine-induced hepatocellular carcinoma in mice

No effective chemopreventive agent has been approved against hepatocellular carcinoma (HCC) to date. Since HCC is one of the hypervascular solid tumors, blocking angiogenesis represents an intriguing approach to HCC chemoprevention. The aim of the current study was to examine the combined effect of the anti-angiogenic agents: leflunomide; a disease modifying antirheumatic drug, perindopril; an angiotensin converting enzyme inhibitor (ACEI) and curcumin; the active principle of turmeric, on diethylnitrosamine (DEN)-induced HCC in mice. Eight weeks following DEN administration, there was a significant rise in immunohistochemical staining of CD31-positive endothelial cells and consequently hepatic microvessel density (MVD) as compared to normal liver. DEN treatment was associated with elevation in hepatic vascular endothelial growth factor (VEGF) level as compared to normal controls (P<0.05, 3842±72pg/ml and 2520.8±97pg/ml, respectively). Similarly, increased hepatic expression of hypoxia inducible growth factor-1α (HIF-1α) was observed in 100% of the DEN-treated animals compared to 0% in their normal counterparts. Treatment with leflunomide, perindopril or curcumin alone abrogated the DEN-induced increased MVD as well as the elevated expression of VEGF, while only curcumin inhibited HIF-1α hepatic expression. Combination of these agents showed further inhibitory action on neovascularization and synergistic attenuation of hepatic VEGF (1954.27±115pg/ml) when compared to each single agent. Histopathological examination revealed a more beneficial chemopreventive activity in the combination group compared to each monotherapy. In conclusion, the combination treatment of leflunomide, perindopril and curcumin targeting different angiogenic pathways, resulted in synergistic inhibition of angiogenesis and consequently more effective chemoprevention of HCC.

Molecular signatures associated with HCV-induced hepatocellular carcinoma and liver metastasis

Hepatocellular carcinomas (HCCs) are a heterogeneous group of tumors that differ in risk factors and genetic alterations. In Italy, particularly Southern Italy, chronic hepatitis C virus (HCV) infection represents the main cause of HCC. Using high-density oligoarrays, we identified consistent differences in gene-expression between HCC and normal liver tissue. Expression patterns in HCC were also readily distinguishable from those associated with liver metastases. To characterize molecular events relevant to hepatocarcinogenesis and identify biomarkers for early HCC detection, gene expression profiling of 71 liver biopsies from HCV-related primary HCC and corresponding HCV-positive non-HCC hepatic tissue, as well as gastrointestinal liver metastases paired with the apparently normal peri-tumoral liver tissue, were compared to 6 liver biopsies from healthy individuals. Characteristic gene signatures were identified when normal tissue was compared with HCV-related primary HCC, corresponding HCV-positive non-HCC as well as gastrointestinal liver metastases. Pathway analysis classified the cellular and biological functions of the genes differentially expressed as related to regulation of gene expression and post-translational modification in HCV-related primary HCC; cellular Growth and Proliferation, and Cell-To-Cell Signaling and Interaction in HCV-related non HCC samples; Cellular Growth and Proliferation and Cell Cycle in metastasis. Also characteristic gene signatures were identified of HCV-HCC progression for early HCC diagnosis.

CONCLUSIONS

A diagnostic molecular signature complementing conventional pathologic assessment was identified.

Minimally invasive evaluation and treatment of colorectal liver metastases

Minimally invasive techniques used in the evaluation and treatment of colorectal liver metastases (CRLMs) include ultrasonography (US), computed tomography, magnetic resonance imaging, percutaneous and operative ablation therapy, standard laparoscopic techniques, robotic techniques, and experimental techniques of natural orifice endoscopic surgery. Laparoscopic techniques range from simple staging laparoscopy with or without laparoscopic intraoperative US, through intermediate techniques including simple liver resections (LRs), to advanced techniques such as major hepatectomies. Hereins, we review minimally invasive evaluation and treatment of CRLM, focusing on a comparison of open LR (OLR) and minimally invasive LR (MILR). Although there are no randomized trials comparing OLR and MILR, nonrandomized data suggest that MILR compares favorably with OLR regarding morbidity, mortality, LOS, and cost, although significant selection bias exists. The future of MILR will likely include expanding criteria for resectability of CRLM and should include both a patient registry and a formalized process for surgeon training and credentialing.

The engagement of selectins and their ligands in colorectal cancer liver metastases

The colonization of the liver by colorectal cancer (CRC) cells is a complicated process which includes many stages, until macrometastases occur. The entrapment of malignant cells within the hepatic sinusoids and their interactions with resident non-parenchymal cells are considered very important for the whole metastatic sequence. In the sinusoids, cell connection and signalling is mediated by multiple cell adhesion molecules, such as the selectins. The three members of the selectin family, E-, P- and L-selectin, in conjunction with sialylated Lewis ligands and CD44 variants, regulate colorectal cell communication and adhesion with platelets, leucocytes, sinusoidal endothelial cells and stellate cells. Their role in CRC liver metastases has been investigated in animal models and human tissue, in vivo and in vitro, in static and shear flow conditions, and their key-function in several molecular pathways has been displayed. Therefore, trials have already commenced aiming to exploit selectins and their ligands in the treatment of benign and malignant diseases. Multiple pharmacological agents have been developed that are being tested for potential therapeutic applications.

Semiautomated segmentation for volumetric analysis of intratumoral ethiodol uptake and subsequent tumor necrosis after chemoembolization

OBJECTIVE

Linear measurements, such as those described by the Response Evaluation Criteria in Solid Tumors (RECIST) criteria, may be limited for assessment of response after transarterial chemoembolization (TACE). The purpose of this pilot study was to show intra- and interobserver reproducibility of volumetric measurements of Ethiodol (ethiodized oil) seen within tumor 24 hours after TACE and of necrotic and viable tumor 1 month after treatment. Volumetric measurements are compared with linear measurements and survival outcomes.

MATERIALS AND METHODS

Between 2006 and 2009, 37 consecutive TACE procedures were performed in 27 patients with hepatic malignancies. CT images obtained 24 hours and 1 month after TACE were retrospectively analyzed. Three observers measured volumes twice. Intraoperator reproducibility was determined using Wilcoxon's signed rank test to assess whether the difference in each volumetric measurement approaches zero. The intraclass correlation coefficient (ICC) and Bland-Altman plots were used to determine interoperator reproducibility. Survival data were retrospectively obtained from the electronic medical record.

RESULTS

Good intraobserver reproducibility and interobserver reproducibility (p > 0.05, ICC > 0.9, respectively) were shown for Ethiodol, whole tumor, and necrotic tumor volumes. The volume of Ethiodol correlated with subsequent necrotic tumor volume (p = 0.009), reduction in whole tumor volume (p = 0.004), and patient survival (p = 0.029). Kaplan-Meier curves suggest that Ethiodol accumulation in more than 50% of the tumor and a 10% or greater increase in the volume of necrotic tumor correlated with survival (p = 0.028 and 0.047, respectively).

CONCLUSION

Semiautomated volumetric analysis can be performed with good intra- and interobserver reproducibility. The volume of Ethiodol accumulated in the tumor after TACE correlates with subsequent necrosis. These early measurements may predict survival outcomes.

Radiofrequency ablation for hepatocellular carcinoma: a survival analysis of 117 patients

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world especially in Asia. Radiofrequency ablation is now commonly use as either first line or in combination with other treatment modality for patients with HCC. It is the objective of this article to report our experience in a tertiary referral hospital.

METHODS

Patients who diagnosed with HCC and underwent RFA in Queen Elizabeth Hospital during the period from May 2002 to February 2009 were included and analyzed.

RESULTS

During this period, 138 sessions of RFA were performed in 117 consecutive patients with HCC. The calculated rate of primary (single attempt) successful ablation during this entire period was 89.2%. The in-hospital/30-day mortality rate was zero, and morbidity was 24.1%. Hospital stays were significantly longer in the open group (4.4 days versus 8.9 days, P = 0.000). Median follow-up in this study was 21 months. 11 (9.4%), 10 (8.5%) and 49 (41.0%) patients developed local tumor progression (LTP), systemic recurrence and Intrahepatic distant recurrence (IDR), respectively. The mean and median times to recurrence were 15.4 and 11 months, respectively. Most patients (91%) with LTP developed in the first 24 months. Disease-free survival was 65% at 1 year, 40% at 3 years and 25% at 5 years. Overall survival at 1, 3 and 5 years was 85, 66 and 40%, respectively. Alpha fetoprotein, aFP > 1,000 ng/ml and multiple tumor ablation predicted increased risk of recurrence.

CONCLUSION

Radiofrequecy ablation is useful tool in treating patients with HCC with high successful rate. However, intrahepatic recurrence is common and a well designed post ablation follow up protocol based on a sound knowledge of recurrence pattern is vital.

Thermal ablative therapies for secondary hepatic malignancies

Hepatic metastatic disease affects more than half of the patients with colorectal cancer and neuroendocrine cancer. Hepatic resection remains the gold standard for liver metastasis from colorectal and neuroendocrine primaries. Thermal ablative technologies, however, are increasingly being used either alone or in combination with resection to treat this group of patients. Radiofrequency ablation is the most common modality used in the United States, whereas microwave ablation has been more widely used in the East. In addition to being adjuncts to hepatic resection, ablation has gained an increased popularity in the management of patients who are not operative candidates or have unresectable colorectal or neuroendocrine hepatic metastasis. Although radiofrequency ablation seems to have a higher local recurrence than resection, ablation remains an important therapeutic option for many patients with hepatic metastasis.

Hepatic tumor ablation

Ablation of liver tumors is part of a multimodality liver-directed strategy in the treatment of various tumors. The goal of ablation is complete tumor destruction, and ultimately improvement of quality and quantity of life for the patient. Technology is evolving rapidly, with important improvements in efficacy. The current state of ablation technology and indications for ablation are described in this review.

Characterisation of a novel cell line (CSQT-2) with high metastatic activity derived from portal vein tumour thrombus of hepatocellular carcinoma

BACKGROUND

Portal vein tumour thrombus (PVTT) is highly associated with the progression and metastasis of hepatocellular carcinoma (HCC). However, there are no appropriate cell models of PVTT with which to study the biological and physiological characteristics of PVTT.

METHODS

Primary cell culture was performed by the use of a successive xenograft line called PVTT-#1, which was obtained from a 60-year-old male HCC patient accompanied by PVTT.

RESULTS

A successive cell line named CSQT-2 was established. The cell line showed aggressive phenotypes in terms of cell growth, survival, migration, xenograft and metastasis. Moreover, an orthotopic transplantation assay showed that PVTT can be generated in nude mice when CSQT-2 cells were inoculated in the liver and that it shows a typical migratory tendency in the vascular branches of portal vein. Moreover, the established CSQT-2 cells also showed varied expression of tumour-initiating cell (TIC) markers such as CD133, CD90 and EpCAM.

CONCLUSION

Establishment of CSQT-2 may provide a suitable model with which to investigate the molecular mechanisms of PVTT-related HCC.