After insufficient radiofrequency ablation, tumor-associated endothelial cells exhibit enhanced angiogenesis and promote invasiveness of residual hepatocellular carcinoma

Prediction of hepatocellular carcinoma biological behavior in patient selection for liver transplantation

Morphological criteria have always been considered the benchmark for selecting hepatocellular carcinoma (HCC) patients for liver transplantation (LT). These criteria, which are often inappropriate to express the tumor’s biological behavior and aggressiveness, offer only a static view of the disease burden and are frequently unable to correctly stratify the tumor recurrence risk after LT. Alpha-fetoprotein (AFP) and its progression as well as AFP-mRNA, AFP-L3%, des-γ-carboxyprothrombin, inflammatory markers and other serological tests appear to be correlated with post-transplant outcomes. Several other markers for patient selection including functional imaging studies such as ¹⁸F-FDG-PET imaging, histological evaluation of tumor grade, tissue-specific biomarkers, and molecular signatures have been outlined in the literature. HCC growth rate and response to pre-transplant therapies can further contribute to the transplant evaluation process of HCC patients. While AFP, its progression, and HCC response to pre-transplant therapy have already been used as a part of an integrated prognostic model for selecting patients, the utility of other markers in the transplant setting is still under investigation. This article intends to review the data in the literature concerning predictors that could be included in an integrated LT selection model and to evaluate the importance of biological aggressiveness in the evaluation process of these patients.

Sorafenib suppresses the epithelial-mesenchymal transition of hepatocellular carcinoma cells after insufficient radiofrequency ablation

BACKGROUND

Epithelial-mesenchymal transition (EMT) played an important role in the progression of hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA). However, whether sorafenib could be used to suppress the EMT of HCC after insufficient RFA and further prevent the progression of residual HCC remains poorly unknown.

METHODS

Insufficient RFA was simulated using a water bath (47 °C 5, 10, 15, 20 and 25 min gradually). MTT assay and transwell assay were used to evaluate the effects of sorafenib on viability, migration and invasion of HepG2 and SMMC7721 cells after insufficient RFA in vitro. After insufficient RFA, the molecular changes in HCC cells with the treatment of sorafeinb were evaluated using western blot and ELISAs. An ectopic nude mice model was used to evaluate the effect of sorafenib on the growth of HepG2 cells in vivo after insufficient RFA.

RESULTS

HepG2 and SMMC7721 cells after insufficient RFA (named as HepG2-H and SMMC7721-H) exhibited enhanced viability, migration and invasion in vitro. Sorafenib inhibited the enhanced viability, migration and invasion of HepG2 and SMMC7721 cells after insufficient RFA. Molecular changes of EMT were observed in HepG2-H and SMMC7721-H cells. Sorafenib inhibited the EMT of HepG2-H and SMMC7721-H cells. HepG2-H cells also exhibited larger tumor size in vivo. Higher expression of PCNA, Ki67, N-cadherin, MMP-2 and MMP-9, was also observed in HepG2-H tumors. Sorafenib blocked the enhanced growth of HepG2 cells in vivo after insufficient RFA.

CONCLUSIONS

Sorafenib inhibited the EMT of HCC cells after insufficient RFA, and may be used to prevent the progression of HCC after RFA.

Inflammation and cancer: inhibiting the progression of residual hepatic VX2 carcinoma by anti-inflammatory drug after incomplete radiofrequency ablation

BACKGROUND

Accelerated progression of residual hepatocellular carcinoma (HCC) after incomplete radiofrequency ablation (RFA) has been reported more frequently. Recent data have redefined the concept of inflammation as a critical component of tumor progression. However, there has been little understanding regarding the relationship between progression of residual HCC and the inflammation induced by thermal destruction of the tumor after RFA. The present study was designed to determine whether inflammation facilitates rapid progression of residual hepatic VX2 carcinoma and to clarify the possible underlying mechanisms.

METHODS

Forty-eight rabbits were each implanted with two VX2 hepatic tumors via supraumbilical median laparotomy. One of the tumors in two different lobes was ablated by RFA. All the rabbits were then randomly divided into four groups (12 rabbits in each group) receiving anti-inflammatory treatment with different doses of aspirin: control group, AS-L group (aspirin, 5 mg/kg/d), AS-M group (aspirin, 20 mg/kg/d), and AS-H group (aspirin, 100 mg/kg/d). The levels of serum interleukin-6 (IL-6), high sensitivity C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were detected to evaluate the effect of the anti-inflammation. Tumor growth, lung and kidney metastasis, and survival were assessed. The expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 9 (MMP-9), vascular endothelial growth factor (VEGF), and cysteinyl aspartate specific proteinase 3 (caspase-3) in residual tumor was examined by immunohistochemistry and Western-blotting.

RESULTS

The levels of serum IL-6, hs-CRP, and TNF-α in the AS-H group decreased significantly in comparison with those of the control group (P<0.05). The focal tumor volume and lung and kidney metastases of rabbits in the AS-H group were less significant compared with those of the control group (P<0.05). The expression of PCNA, MMP-9, and VEGF in the AS-H group decreased significantly compared with the control group (P<0.05). Finally, the survival time of the AS-H group was longer than that of the control group (P<0.05).

CONCLUSIONS

Inflammation induced by thermal destruction of the tumor following RFA could be an important cause of rapid progression of residual hepatic VX2 carcinoma. The anti-inflammation effect of aspirin can inhibit proliferation, invasion, and metastasis of residual tumor cells, and aspirin may be a good candidate drug as an adjuvant therapy with RFA for treating HCC.

Radiofrequency ablation for single hepatocellular carcinoma 3 cm or less as first-line treatment

AIM

To evaluate long-term outcomes of radiofrequency (RF) ablation as first-line therapy for single hepatocellular carcinoma (HCC) ≤ 3 cm and to determine survival and prognostic factors.

METHODS

We included all 184 patients who underwent RF ablation as a first-line treatment for single HCC ≤ 3 cm between April 2005 and December 2013. According to the criteria of Livraghi, the 184 patients were divided into two groups: those suitable for surgical resection (84 cases) and those unsuitable for surgical resection (100 cases). The primary endpoints were the overall survival (OS) rate and safety; the secondary endpoints were primary technique effectiveness and recurrence rate.

RESULTS

There were 19 (10.3%) cases of ablation related minor complications. The complete tumor ablation rate after one RF session was 97.8% (180/184). The rate of local tumor progression, extrahepatic metastases and intrahepatic distant recurrence were 4.9% (9/184), 9.8% (18/184) and 37.5% (69/184), respectively. In the 184 patients, the 1-, 3-, and 5-year OS rates were 99.5%, 81.0%, and 62.5%, respectively. The 1-, 3-, and 5-year OS rates were 100%, 86.9%, and 71.4%, respectively, in those suitable for surgical resection and 99.0%, 76.0%, and 55.0%, respectively, in those unsuitable for surgical resection (P = 0.021). On univariate and multivariate analyses, poorer OS was associated with Child-Pugh B class and portal hypertension (P < 0.05).

CONCLUSION

RF ablation is a safe and effective treatment for single HCC ≤ 3 cm. The OS rate of patients suitable for surgical resection was similar to those reported in surgical series.

Surgical and Pathological Changes after Radiofrequency Ablation of Thyroid Nodules

Background. Radiofrequency ablation (RFA) has been recently advocated as an effective technique for the treatment of symptomatic benign thyroid nodules. It is not known to what extent it may affect any subsequent thyroid surgery and/or histological diagnosis. Materials and Methods. RFA was performed on 64 symptomatic Thy2 nodules (benign nodules) and 6 symptomatic Thy3 nodules (follicular lesions/follicular neoplasms). Two Thy3 nodules regrew after the procedure, and these patients accepted to undergo a total thyroidectomy. Here we present how RFA has affected the operation and the final pathological features of the surgically removed nodules. Results and Conclusions. RFA is effective for the treatment of Thy2 nodules, but it should not be recommended as first-line therapy for the treatment of Thy3 nodules (irrespective of their mutational status), as it delays surgery in case of malignancy. Moreover, it is unknown whether RFA might promote residual tumor progression or neoplastic progression of Thy3 lesions. Nevertheless, here we show for the first time that one session of RFA does not affect subsequent thyroid surgery and/or histological diagnosis.

Incomplete radiofrequency ablation enhances invasiveness and metastasis of residual cancer of hepatocellular carcinoma cell HCCLM3 via activating β-catenin signaling

BACKGROUND

Radiofrequency ablation (RFA) is one of the curative therapies for hepatocellular carcinoma (HCC), however, accelerated progression of residual HCC after incomplete RFA has been reported more frequently. The underlying molecular mechanism of this phenomenon remains to be elucidated. In this study, we used an incomplete RFA orthotopic HCC nude mouse model to study the invasive and metastatic potential of residual cancer as well as the correlated mechanism.

METHODS

The incomplete RFA orthotopic nude mouse models were established using high metastatic potential HCC cell line HCCLM3 and low metastatic potential HCC cell line HepG2, respectively. The changes in cellular morphology, motility, metastasis and epithelial-mesenchymal transition (EMT), and HCC cell molecular markers after in vitro and in vivo incomplete RFA intervention were observed.

RESULTS

Pulmonary and intraperitoneal metastasis were observed in an in vivo study. The underlying pro-invasive mechanism of incomplete RFA appeared to be associated with promoting EMT, including down-regulation of E-cadherin and up-regulation of N-cadherin and vimentin. These results were in accordance with the in vitro response of HCC cells to heat intervention. Further studies demonstrated that β-catenin was a pivotal factor during this course and blocking β-catenin reduced metastasis and EMT phenotype changes in heat-treated HCCLM3 cells in vitro.

CONCLUSION

Incomplete RFA enhanced the invasive and metastatic potential of residual cancer, accompanying with EMT-like phenotype changes by activating β-catenin signaling in HCCLM3 cells.

Multimodality therapy and liver transplantation for hepatocellular carcinoma: a 14-year prospective analysis of outcomes

BACKGROUND

Hepatocellular carcinoma is a major cause of death among patients with cirrhosis. A standardized approach of multimodality therapy with intent-to-treat by transplantation for all patients with hepatocellular carcinoma was instituted at our transplant center in 1997. Data were prospectively collected to evaluate the impact of multimodality therapy on posttransplant patient survival, tumor recurrence, and patient survival without transplantation.

METHODS

All patients with hepatocellular carcinoma were eligible for multimodality therapy. Multimodality therapy consisted of hepatic resection, radiofrequency ablation, transarterial chemoembolization, transarterial chemoinfusion, yttrium-90 microsphere radioembolization, and sorafenib.

RESULTS

Approximately 715 patients underwent multimodality therapy; 231 patients were included in the intent-to-treat with transplantation arm, and 484 patients were treated with multimodality therapy or palliative therapy because of contraindications for transplantation. A 60.2% transplantation rate was achieved in the intent-to-treat with transplantation arm. Posttransplant survivals at 1 and 5 years were 97.1% and 72.5%, respectively. Tumor recurrence rates at 1, 3, and 5 years were 2.4%, 6.2%, and 11.6%, respectively. Patients with contraindications to transplant had increased 1- and 5-year survival from diagnosis with multimodality therapy compared with those not treated (73.1% and 46.5% versus 15.5% and 4.4%, P<0.0001).

CONCLUSIONS

Using multimodality therapy before liver transplantation for hepatocellular carcinoma achieved low recurrence rates and posttransplant survival equivalent to patients with primary liver disease without hepatocellular carcinoma. Multimodality therapy may help identify patients with less active tumor biology and result in improved disease-free survival and organ utilization.

Role of the tissue microenvironment as a therapeutic target in hepatocellular carcinoma

Hepatocellular carcinoma is difficult to treat, primarily because the underlying molecular mechanisms driving clinical outcome are still poorly understood. Growing evidence suggests that the tissue microenvironment has a role in the biological behavior of the tumor. The main clinical issue is to identify the best target for therapeutic approaches. Here, we discuss the hypothesis that the entire tissue microenvironment might be considered as a biological target. However, the tissue microenvironment consists of several cellular and biochemical components, each of which displays a distinct biological activity. We discuss the major components of this environment and consider how they may interact to promote tumor/host crosstalk.

TGF-β Mediated Crosstalk Between Malignant Hepatocyte and Tumor Microenvironment in Hepatocellular Carcinoma

In this article, we have reviewed current literature regarding the regulation of hepatocellular carcinoma (HCC) by the interaction of malignant hepatocytes and their tissue environment through cytokine signaling, here represented by transforming growth factor-beta (TGF-β) signaling. We have discussed responses of TGF-β signaling in transition of hepatic stellate cells to myofibroblasts (MFBs), recruitment of tumor-associated macrophages (TAMs), and enrichment of tumor-associated endothelial cells (TECs). The malignant hepatocytes also secrete various factors such as platelet-derived growth factors (PDGFs), vascular endothelial growth factor (VEGF), and TGF-β. TGF-β, a super-family of cytokines, creates tumor microenvironment by interacting through other growth factors (epidermal growth factor receptor (EGFR), PDGF, fibroblast growth factor (FGF), hepatocyte growth factor (HGF), VEGF), cytokines and chemokines, and extracellular matrix (ECM) remodeling. Hence, the HCC tumor microenvironment may now be recognized as an important participant of tumor progression to act as potential target to systemic therapies compared to targeted therapies.

Molecular targeting agents associated with transarterial chemoembolization or radiofrequency ablation in hepatocarcinoma treatment

Hepatocellular carcinoma (HCC) is the fifth most common cause of cancer in the world. According to Barcelona Clinic Liver Cancer modified criteria, patients with early stage disease are candidate to radiofrequency ablation (RFA), while patients with intermediate stage HCC are usually treated by transarterial chemoembolization (TACE). TACE and RFA induce a transient devascularisation effect followed by strong neo-angiogenic stimulus. In fact, after these procedures, it has been demonstrated an up-regulation of pro-angiogenic and growth factors such as vascular endothelial growth factor-A, which might contribute to accelerated progression in patients with incomplete response. Several studies have demonstrated that MAP-kinase and AKT pathways, in addition to neo-angiogenesis, have an important role in the development of HCC. In advanced HCC, anti-angiogenic therapy and tyrosine kinases inhibitors showed potential clinical benefit. Actually, a number of clinical studies are ongoing testing these agents in combination with TACE or RFA. In this paper, we have reviewed the most recent preclinical and clinical results of such trials.

Radiofrequency ablation of hepatocellular carcinoma sized > 3 and ≤ 5 cm: Is ablative margin of more than 1 cm justified?

AIM: To investigate whether an ablative margin (AM) > 1.0 cm might reduce chance of recurrence for patients with hepatocellular carcinoma (HCC) tumors 3.1 to 5.0 cm in size, compared with an AM of 0.5-1.0 cm.

METHODS: From October 2005 to December 2012, 936 consecutive patients with HCC who received radiofrequency ablation were screened. Of these, 281 patients, each with a single primary HCC tumor of 3.1 to 5.0 cm in size on its greatest diameter, were included in the study. Based on the AM width, we categorized patients into the 0.5-1.0 cm group and the > 1.0 cm group. Local tumor progression (LTP)-free survival, intrahepatic distant recurrence (IDR)-free survival and overall survival (OS) rates were obtained using the Kaplan-Meier method.

RESULTS: The 1-, 2-, 3-, 4-, and 5-year LTP-free survival rates and IDR-free survival rates were significantly higher in the > 1.0 cm group compared with the 0.5-1.0 cm group (97.5%, 86.3%, 73.6%, 49.5% and 26.4% vs 91.3%, 78.4%, 49.5%, 27.8%, and 12.8%; 95.1%, 90.3%, 77.0%, 61.0% and 48.3% vs 95.2%, 85.9%, 62.6%, 47.2% and 28.5%; P < 0.05). The 1-, 2-, 3-, 4-, and 5-year OS rates were 98.6%, 91.5%, 69.2%, 56.0% and 42.2%, respectively, in the 0.5-1.0 cm group and 100%, 98.9%, 90.1%, 68.7% and 57.4%, respectively, in the > 1.0 cm group (P = 0.010). There were no significant differences in complication rates between the two groups. Both univariate and multivariate analyses identified AM as an independent prognostic factor linked to LTP, IDR, and OS.

CONCLUSION: For HCC tumors > 3.0 cm and ≤ 5.0 cm, AM > 1.0 cm could reduce chances of recurrence compared with AM of 0.5-1.0 cm, emphasizing the need for a more defensive strategy using AMs > 1.0 cm for ablating HCC tumors of 3.1 to 5.0 cm.

Insufficient radiofrequency ablation promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells through Akt and ERK signaling pathways

Background

Residual tumor progression after insufficient radiofrequency ablation (RFA) has been recently reported. However, whether epithelial-mesenchymal transition (EMT), which is a key process that drives cancer metastasis, is involved in the tumor progression after insufficient RFA is not well understood.

Methods

Human hepatocellular carcinoma (HCC) cell lines SMMC7721 and Huh7 were used. Insufficient RFA was simulated using a water bath (47°C 5 min, 10 min, 15 min, 20 min and 25 min gradually). MTT assay was used to evaluate the proliferation of HCC cells in vitro. Migration and invasion of HCC cells were determined by transwell assay. The molecular changes in HCC cells after insufficient RFA were evaluated by western blot. LY294002 and PD98059 were used to treat HCC cells. An ectopic nude mice model and a tail vein metastatic assay were used to evaluate the growth and metastatic potential of SMMC7721 cells in vivo after insufficient RFA.

Results

SMMC7721 and Huh7 cells after insufficient RFA (named as SMMC7721-H and Huh7-H respectively) exhibited enhanced proliferation, migration and invasion (6.4% and 23.6%, 33.2% and 66.1%, and 44.1% and 57.4% increase respectively) in vitro. Molecular changes of EMT were observed in SMMC7721-H and Huh7-H cells. LY294002 and PD98059 inhibited the EMT of SMMC7721-H and Huh7-H cells. SMMC7721-H cells also exhibited larger tumor size (1440.8 ± 250.3 mm³ versus 1048.56 ± 227.6 mm³) and more lung metastasis (97.4% increase) than SMMC7721 cells in vivo. Higher expression of PCNA, N-cadherin and MMP-2 and MMP-9, was also observed in SMMC7721-H tumors.

Conclusions

Insufficient RFA could directly promote the invasiveness and metastasis of HCC cells. Insufficient RFA may promote the EMT of HCC cells through Akt and ERK signaling pathways.

Vascular endothelial cells facilitated HCC invasion and metastasis through the Akt and NF-κB pathways induced by paracrine cytokines

Background

It is well documented that cancer cells secrete angiogenic factors to recruit and sustain tumor vascular networks. However, little is known about the effects of endothelial cells on the behavior of tumor cells. The study here was to determine the roles of endothelial cells in HCC cell growth, migration and invasion.

Methods

A mixture of highly metastatic MHCC97H cells and HUVEC cells, as well as MHCC97H cells alone were subcutaneously injected into nude mice to observe the effects of HUVECs on HCC growth. The biological characteristics of MHCC97H cells respectively treated with conditioned medium (CM) derived from HUVECs and endothelial cell basal medium (EBM) in vitro, such as proliferation, migration and invasion, invasion/metastasis associated gene expression, were comparatively analyzed. Differential cytokines between CM and EBM were screened and identified using human cytokine array. Effects of the interested differential cytokine CCL2, IL-8 and CXCL16 and its related signaling pathways were further investigated in HCC cells.

Results

Subcutaneous tumorigenicity of MHCC97H cells in nude mice was promoted by HUVECs and its invasion/metastasis associated genes were significantly upregulated. The in vitro, proliferation, migration and invasion of HCC cells treated with CM were all significantly enhanced as compared to those with EBM stimulation. Simultaneously, PI3K/Akt and ERK1/2 pathway in HCC cells were activated by CM. Total of 25 differential cytokines were identified between CM and EBM such as angiopoietin-2, CCL2 (MCP-1), uPA, endostatin, CXCL16, IL-8, pentraxin 3 etc. The selected differential cytokines CCL2, IL-8 and CXCL16 all modulated the expressions of HCC invasion/metastasis genes, especially MMP2 and MMP9. In exposure to CCL2 or CXCL16 alone, upregulation in AKT phosphorylation but no change in ERK phosphorylation were found in MHCC97H cells, moreover the contents of nuclear transcription factor NF-κB were increased as compared to the control. However, no effects on the activation of Akt and ERK pathway in MHCC97H were found in exposure to IL-8.

Conclusion

This study expands the contribution of endothelial cells to the progression of HCC. It unveils a new paradigm in which endothelial cells function as initiators of molecular crosstalks that enhance survival, migration and invasion of HCC cells.