Hepatocellular necrosis, apoptosis, and proliferation after transcatheter arterial embolization or chemoembolization in a standardized rabbit model

How Biology Guides the Combination of Locoregional Interventional Therapies and Immunotherapy for Hepatocellular Carcinoma: Cytokines and Their Roles

As most patients with hepatocellular carcinoma (HCC) are diagnosed at the intermediate or advanced stage and are no longer eligible for curative treatment, the overall survival rate of HCC remains unsatisfactory. Locoregional interventional therapies (LITs), and immune checkpoint inhibitor (ICI)-based immunotherapy, focus on treating HCC, but the efficacy of their individual application is limited. Therefore, the purpose of this review was to discuss the biological roles of cytokines and their therapeutic potential in the combination therapy of LITs and ICI-based immunotherapy. The two common techniques of LITs are ablative and transarterial therapies. Whether LITs are complete or incomplete can largely affect the antitumor immune response and tumor progression. Cytokines that induce both local and systemic responses to LITs, including interferons, interleukins, chemokines, TNF-α, TGF-β, VEGF, and HGF, and their roles are discussed in detail. In addition, specific cytokines that can be used as therapeutic targets to reduce immune-related adverse events (irAEs) are introduced. Overall, incomplete LITs in a tumor, combined with specific cytokines, are thought to be effective at improving the therapeutic efficacy and reducing treatment-induced irAEs, and represent a new hope for managing unresectable HCC.

Doxorubicin-Loaded UiO-66/Bi2S3 Nanocomposite-Enhanced Synergistic Transarterial Chemoembolization and Photothermal Therapy against Hepatocellular Carcinoma

Transcatheter arterial chemoembolization (TACE) is the first choice for patients with intermediate hepatocellular carcinoma (HCC), but clinical applications still face some problems, such as the difficulties in clearing all cancer cells and lack of targeting, which would damage normal liver cells. Recently, photothermal therapy (PTT) and nanodelivery systems have been used to improve the efficacy of TACE. However, most of these strategies achieve only a single function, and the synthesis process is complicated. Here, a simple one-step solvothermal method was used to develop multifunctional nanoparticles (UiO-66/Bi₂S₃@DOX), which can simultaneously achieve photothermal effects and low pH-triggered DOX release. UiO-66/Bi₂S₃ exhibited a pH-responsive release behavior and an excellent photothermal effect in a series of in vitro and in vivo studies. Biocompatibility was confirmed by cytotoxicity and hemocompatibility evaluations. The rat N1S1 liver tumor model was established to investigate the therapeutic effect and biosafety of the nanoplatforms using TACE. The results revealed that the combination of TACE and PTT resulted in remarkable tumor growth inhibition, and the histopathological assay further revealed extensive necrosis, downregulated angiogenesis, increased apoptosis, and proliferation in the tumor response. These results demonstrated that this nanosystem platform was a promising therapeutic agent for enhancing TACE therapy for HCC treatment.

Effects of transarterial chemoembolization on regulatory T cell and its subpopulations in patients with hepatocellular carcinoma

BACKGROUND

Regulatory T cell (Treg) plays an essential role in regulating anti-tumor immunity. The aim of this study was to investigate the effect of transarterial chemoembolization (TACE) on Treg in hepatocellular carcinoma (HCC) patients.

METHOD

The frequency of peripheral blood Tregs in 27 HCC patients who underwent TACE were measured at baseline and 1 month after TACE. The frequency of peripheral blood Tregs at baseline were compared with those in 23 healthy controls. Tregs were further classified into three subpopulations [Treg (I), Treg (II), Treg (III)] based on expression levels or markers and their function. The patients were divided into two groups according to tumor response after TACE; complete response group and incomplete response group. The correlations between the frequency of Treg and clinical factors were analyzed.

RESULTS

The frequency of Treg in HCC patients (7.52%) was significantly higher than in healthy controls (4.99%) at baseline. Regarding Treg subpopulations, the frequency of Treg (II) was significantly higher in HCC patients (2.51%) than in healthy controls (0.60%). In comparison of Treg numbers at baseline and post-TACE by tumor response, the change of Treg (III) in complete response group from baseline to post-TACE was significantly decreased (63.8 → 53.2/mm³). Patients with a high post-TACE Treg (III) (3.8 months) exhibited a significantly shorter median time to progression than those with a low post-TACE Treg (III) (11.6 months). In multivariate analyses, hypoalbuminemia (hazard ratio 3.324; 95% CI 1.098-10.063, p = 0.034) and high post-TACE Treg (III) (hazard ratio 3.080; 95% CI 1.091-8.696, p = 0.034) were significant factors for associating with progression.

CONCLUSIONS

The frequency of Tregs in HCC patients was significantly higher than in healthy controls. In addition, patients with a high post-TACE Treg (III) exhibited a significantly lower progression-free survival rate than those with a low post-TACE Treg (III).

Intra-arterial EmboCept S® and DC Bead® effectively inhibit tumor growth of colorectal rat liver metastases

BACKGROUND

Intra-arterial therapy with embolics is established for the treatment of malignancies of the liver. However, there are no studies comparing the different effects of various embolics used in clinical practice. Herein, we analyzed the effect of 3 different embolics on tumor growth in a rat model of colorectal liver metastases.

METHODS

Eight days after subcapsular implantation of 5 × 105 colorectal cancer cells (CC531) in the left liver lobe of WAG/Rij rats were randomized into 4 groups (n = 8) and underwent intra-arterial hepatic therapy. Animals received either EmboCept S®, DC Bead® or Lipiodol® Ultra-Fluid. Animals of the control group received a comparable amount of saline. Tumor growth was measured on day 8 and 11 using a three-dimensional 40 MHz ultrasound device. On day 11 tumor and liver tissue were removed for histological and immunohistochemical analyses.

RESULTS

On day 11 animals of the control group showed a tumor growth of ~ 60% compared to day 8. Application of Lipiodol Ultra-Fluid® did not significantly influence tumor growth (~ 40%). In contrast, treatment with EmboCept S® or DC Bead® completely inhibited tumor growth. Of interest, application of EmboCept S® did not only completely inhibit tumor growth but even decreased tumor size. Immunohistochemical analysis showed a significant increase of necrotic areas within the tumors after application of EmboCept S® and DC Bead® compared to Lipiodol® Ultra-Fluid.

CONCLUSION

The present study demonstrates that an intra-arterial therapy with EmboCept S® and DC Bead®, but not Lipiodol® Ultra-Fluid, results in a complete inhibition of rat colorectal liver metastatic growth.

The prognostic and predictive value of the combination of the neutrophil-to-lymphocyte ratio and the platelet-to-lymphocyte ratio in patients with hepatocellular carcinoma who receive transarterial chemoembolization therapy

Purpose

This study was designed to evaluate the prognostic value of the combination of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) (neutrophil/platelet-to-lymphocyte ratio [NLR–PLR]) in patients with hepatocellular carcinoma (HCC) who receive transarterial chemoembolization (TACE) therapy.

Patients and methods

Data from 216 patients who were diagnosed with HCC after TACE therapy were retrospectively collected. R software was used to analyze the time-dependent receiver operating characteristic (ROC) curves and to compare the area under the ROC curves (AUROCs).

Results

The long-term survival rates were significantly higher for patients with lower values than those with higher values of NLR, PLR, and NLR–PLR. The mean overall survival decreased gradually with increases in the NLR–PLR score (P<0.0001). The AUROC values of the NLR–PLR score were consistently higher than those of NLR and PLR.

Conclusion

This study showed that the NLR–PLR score might be a useful predictor for patients with HCC who receive TACE therapy.

Mechanism of action and efficacy of LY2109761, a TGF-β receptor inhibitor, targeting tumor microenvironment in liver cancer after TACE

TACE (transcatheter arterial chemoembolization) has been recognized as an effective palliative treatment option for patients with HCC, however, the medium-long term efficacy of it remains modest. LY2109761, a TGF-β receptor inhibitor, was confirmed to reduce tumor cell growth, intravasation, and metastatic dissemination of HCC cells through different molecular mechanisms. This study aims to investigate the treatment effect of combining TACE therapy with LY2109761- a TGF-β receptor I kinase inhibitor on suppressing tumor growth and metastasis in a rabbit VX2 tumor model. The molecular mechanisms underlying the biological activities of LY2109761 was also evaluated through an in vitro model. And we found that LY2109761 could inhibit cell proliferation by down-regulating the phosphorylation of Smad-2 as well as improved the therapeutic effect of TACE in a VX2 hepatocellular carcinoma model. And we further found that LY2109761 may play a modulating role in the process of T cell transformation. Hence, based on those obsevations in our research, we concluded that combing LY2109761 with TACE for the treatment of VX2 rabbit liver cancer can help inhibit tumor growth as well as increase the tumor cell necrosis after TACE.

Risk factors of early recurrence after curative hepatectomy in hepatocellular carcinoma

Early recurrence is common after curative hepatectomy for hepatocellular carcinoma and is associated with poor prognosis. This study aimed to identify risk factors of early recurrence after curative hepatectomy in hepatocellular carcinoma. Overall, 63 patients who underwent curative hepatectomy for hepatocellular carcinoma were enrolled. Patients were divided into the early recurrence group, who developed recurrence within 12 months after hepatectomy (n = 10), and the non-early recurrence group (n = 53). Clinicopathological factors of early recurrence were retrospectively analyzed. Among the 63 patients, 10 (15.9%) patients experienced early recurrence. Univariate analysis showed tumor necrosis (p = 0.012), level of PIVKA-II (prothrombin induced by vitamin K absence or antagonist-II; p = 0.002), and microvascular invasion (p = 0.029) to be associated with early recurrence. By multivariate analysis, there were significant differences in high PIVKA-II (p < 0.001) and tumor necrosis (p = 0.012) in patients with early recurrence. The optimal cutoff values of PIVKA-II and tumor necrosis were 46 mAU/mL and 3% of total tumor volume, respectively. Patients with a high preoperative PIVKA-II level and extent of tumor necrosis, which are independent risk factors for early recurrence, should be actively treated and monitored closely after hepatectomy.

Factors affecting the recurrence and survival of hepatocellular carcinoma after hepatectomy: a retrospective study of 601 Chinese patients

OBJECTIVE

Indications for resection of hepatocellular carcinoma (HCC) remain controversial. This study aimed to identify prognostic factors that affect overall survival (OS) and disease-free survival (DFS) in patients with HCC after hepatectomy.

METHODS

From 2004 to 2010, 601 patients with HCC who underwent resection were enrolled. Factors stratified into the host, biochemical, surgical treatment and tumor-related features in terms of recurrence and overall survival were analyzed. Prognostic factors were evaluated by univariate and multivariate analyses, with Kaplan-Meier survival analyses and Cox proportional hazard model.

RESULTS

The overall survival rates of 1-, 3- and 5- year were 79, 62, and 54 %, and the corresponding DFS rates were 51, 38 and 31 %, respectively. In a multivariate analysis, Child-Pugh, serum AFP level, ALT level, time for hepatic resection, tumor differentiation, maximum size of tumors, local necrosis, portal vein tumor thrombus, and TNM Stage were correlated significantly with patients' OS. Gender (P = 0.046), cigarette smoking (P = 0.007), serum AFP level (P = 0.001), GGT level (P = 0.002), maximum size of tumors (P = 0.009), liver cirrhosis (P = 0.025), portal vein tumor thrombus (P = 0.022), microvascular tumor thrombus (P = 0.007) and TNM Stage (P = 0.001) were significantly affected DFS.

CONCLUSION

Preoperative AFP level, maximum size of tumors, portal vein tumor thrombus and TNM Stage were revealed as important prognostic factors for OS and DFS through follow-up of a relatively large cohort of Chinese HCC patients.

Imbalance in systemic inflammation and immune response following transarterial chemoembolization potentially increases metastatic risk in huge hepatocellular carcinoma

Inflammation plays a critical role in tumor metastasis. However, few inflammation-related biomarkers are currently available to predict the risk of metastasis for advanced hepatocellular carcinoma (HCC). Using huge tumors (diameter >10 cm) as a model, we evaluated the potential risk of pre- and post-treatment inflammatory responses in the development of metastasis of HCC patients undergoing transarterial chemoembolization (TACE). A logistic regression model was used to analyze the risk factors. One hundred and sixty-five patients with huge HCC were enrolled in the study. Metastases were identified in 25.5% (42/165) patients by imaging evaluation post-TACE. Neutrophils increased, whereas lymphocytes decreased significantly post-TACE. Univariate analysis showed that high post-treatment neutrophil-to-lymphocyte ratio (NLR; p = 0.003), low post-treatment lymphocyte count (p = 0.047), and high baseline NLR (p = 0.100) were potential risk factors for metastasis. Further, multivariate analysis showed that high post-treatment NLR, but not pre-treatment NLR, was an independent risk factor for metastasis; this was confirmed by receiver operating characteristic curve analysis. Post-treatment NLR, however, had no correlation to tumor response and overall survival of patients. In conclusion, post-treatment NLR but not pre-treatment NLR independently increases the risk of metastasis in huge HCC. Our findings suggest the potential contribution of treatment-related inflammation to metastasis in advanced HCC.

Therapeutic effects of transarterial infusion of lipiodol and ethanol in various ratios in a rabbit VX2 tumor model

PURPOSE

We aimed to evaluate the therapeutic effect and safety of transcatheter arterial embolization with various volume ratios of lipiodol and ethanol in a rabbit VX2 tumor model to identify the optimal volume ratio.

METHODS

Eighteen adult male New Zealand white rabbits implanted with VX2 tumors in their left liver lobes were randomly divided into six groups based on volume ratios of lipiodol to ethanol: group A, 3:1; group B, 2:1; group C, 1:1; group D, 1:2; group E, 1:3; and group F, 1:4. Pre- and post-treatment unenhanced magnetic resonance imaging was used to detect tumor formation and evaluate tumor growth rates. Liver samples were harvested one week after the procedure, and apoptosis index of tumor tissues was evaluated by pathologic examination and TUNEL assay.

RESULTS

Tumor size decreased in groups B, C, and D, but increased in groups A, E, and F. Tumor growth rates in groups A-F were 0.40±0.03, -0.11±0.21, -0.08±0.09, -0.12±0.07, 0.06±0.12, and 0.05±0.09, respectively. The change in tumor size was significantly different in group A compared with the rest of the groups, but no significant difference was observed among groups B-F. Apoptosis indexes of the six groups were 4.7±2.1%, 6.7±2.1%, 11.7±3.1%, 11.0±2.0%, 10.7±3.2%, and 12±3%, respectively. Apoptosis index was significantly lower in group A compared with groups C-F (P < 0.05). Apoptosis index of group B was significantly lower than groups C and F. There was no significant difference among the other groups.

CONCLUSION

The volume ratios of lipiodol to ethanol ranging from 2:1 to 1:4 were equally effective, the ratios 2:1 and 1:3 had equal safety, and the ratios 1:1 and 1:2 indicated better long-term therapeutic effect. Increasing ethanol in the mixture caused more severe liver injury. Optimal efficacy and safety was achieved with a lipiodol to ethanol volume ratio of 1:1.

Radiofrequency ablation combined with transcatheter therapy in rabbit VX2 liver tumors: effects and histopathological characteristics

BACKGROUND

Transarterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) treatment (TACE-RFA) has been confirmed superior to TACE or RFA alone in animal liver tumors. TACE before RFA was shown to increase hepatocellular damage. Further optimization of the combination strategy for transcatheter arterial embolization (TAE) or TACE combined with RFA is warranted.

PURPOSE

To determine the optimal strategy for radiofrequency ablation combined with transcatheter therapies in VX2 liver tumors in a rabbit model.

MATERIAL AND METHODS

Twenty-four Japanese White rabbits with VX2 liver tumors were randomly divided into four groups: TACE-RFA (TACE-RFA group), transcatheter arterial embolization (TAE) combined with RFA treatment (TAE-RFA group), RFA only group, and TACE only group. Blood samples were collected 1 day before the operation and at 3 and 7 days postoperatively. Seven days after the operation, maximal diameters of coagulation or infarcted zones in the gross specimens, CT images, histopathological characteristics, tumor necrotic rate, and growth rate were compared.

RESULTS

Significantly larger mean long-axis (P < 0.05) and short-axis (P < 0.05) diameters of coagulation and infarction were observed in the TACE-RFA group compared with the TAE-RFA, RFA, and TACE groups on day 7; and the TAE-RFA group showed a significant (P < 0.05) increase versus the RFA and TACE groups on day 7. There were no significant differences in tumor growth rate (109.3 ± 37.5 vs. 119.0 ± 43.1%, P = 0.45) and necrotic rate (89.5 ± 12.0 vs. 83.5 ± 9.3%, P = 0.73) between the TACE-RFA and TAE-RFA groups. TACE-RFA was more effective for achieving tumor destruction than the other treatment strategies, but led to increased rabbits discomfort and more severe liver dysfunction compared with TAE-RFA.

CONCLUSION

TAE-RFA appears to be a beneficial therapeutic modality for treating VX2 liver tumors in a rabbit model.

Dynamical observation on biological progression of VX2 liver tumors to identify the optimal time for intervention in animal models

Purpose

Based on practice guideline of “management of hepatocellular carcinoma (HCC): update” published by American Association for the Study of Liver Diseases (AASLD) and “Barcelona Clinic Liver Cancer staging system (BCLC),” this study investigated how to enroll the optimal VX2 liver tumor model for HCC researches by dynamically observing the biological progression of the tumor.

Materials

Thirty-two healthy New Zealand white rabbits were implanted VX2 liver tumor by cell suspension method (n=24) and tissue fragment method (n=8). All the rabbits underwent CT scans on day 7, 14, 21 and 28 after implantation to observe the size of the tumors, the time when metastases and ascites occurred and the survival time. Appropriate intervention times were estimated corresponding to different clinical HCC stages by using tumor diameter-time curve.

Results

The VX2 liver tumors grew rapidly within 28 days after implantation. And the tumors in the cell suspension group grew faster than those of the tissue fragment group. The appropriate intervention time corresponding to very early stage, early stage and intermediate stage were <11 days, 11–16.9 days and >16.9 days, respectively in the cell suspension group, and <19.9 days, 19.9–25.5 days and >25.5 days, respectively in the tissue fragment group.

Conclusion

Preclinical animal research needs to improve on different levels to yield best predictions for human patients. Researchers should seek for an individualized proposal to select optimal VX2 liver tumor models for their experiments. This approach may lead to a more accurate determination of therapeutic outcomes.

Hepatic parenchymal changes following transcatheter embolization and chemoembolization in a rabbit tumor model

OBJECTIVE

To compare the effects of transcatheter arterial chemoembolization (TACE) with transcatheter arterial embolization (TAE) on liver function, hepatic damage, and hepatic fibrogenesis in a rabbit tumor model.

MATERIALS AND METHODS

Thirty-nine New Zealand white rabbits implanted with VX2 tumors in the left liver lobes were randomly divided into three groups: TAE, TACE, and control group. In the TAE group (n = 15), polyvinyl alcohol particles (PVAs) were used for left hepatic artery embolization. In the TACE group (n = 15), the tumors were treated with left hepatic arterial infusions of a suspension of 10-hydroxycamptothecin and lipiodol, followed by embolization with PVAs. In the control group (n = 9), the animals received sham treatment with distilled water. Serum and liver samples were collected at 6 hours, 3 days and 7 days after treatment. Liver damage was measured using a liver function test and histological analyses. Liver fibrogenesis and hepatic stellate cell (HSC) activation were evaluated using Sirius Red and anti-alpha-smooth muscle actin (α-SMA) immunohistochemical stains.

RESULTS

TACE caused liver injury with greater increases in serum alanine aminotransferase and aspartate aminotransferase levels on day 3 (P<0.05). Histological analyses revealed increased hepatic necrosis in adjacent non-tumorous liver tissue from day 3 compared to the TAE group (Suzuki score of 2.33±1.29 versus 1.13±1.18, P = 0.001). HSC activation and proliferation were significantly increased in the TACE group compared to the control group at 3 and 7 days after treatment (0.074±0.014 vs. 0.010±0.006, and 0.088±0.023 vs. 0.017±0.009, P<0.05). Sirius Red staining demonstrated a statistically significant increase in collagen deposition in the livers in the TACE group 7 days after embolization compared to the control group (0.118±0.012 vs. 0.060±0.017, P = 0.05).

CONCLUSION

The results of this animal study revealed that TACE induced prominent hepatocellular damage and hepatic fibrogenesis, which compromised liver function and may be responsible for chronic liver decompensation.