c-Met/MAPK pathway promotes the malignant progression of residual hepatocellular carcinoma cells after insufficient radiofrequency ablation

Radiofrequency ablation combined with immunotherapy to treat hepatocellular carcinoma: a comprehensive review

BACKGROUND AND AIM

Hepatocellular carcinoma (HCC) is a highly immunogenic tumor and the third leading cause of cancer-related deaths worldwide with an increasing incidence. Therefore, the combination of immunotherapy with other approaches, such as anti-angiogenic agents and local area therapy, has become a new strategy for HCC treatment.

METHODS

We searched PubMed and Web of Science and extracted publications relating to the radiofrequency ablation (RFA) and immunotherapy. The search terms were: "radiofrequency ablation", "immunotherapy" and "hepatocellular carcinoma", and manual searches of eligible articles from literature reference lists were performed. We then thoroughly reviewed the literature on ablation combined with immunotherapy for HCC, analyzed the relevant mechanism, and explored the safety and effectiveness of this form of combination therapy.

RESULTS

RFA combined with immunotherapy in HCC is reported to have good efficacy and controllable safety. On the one hand, RFA can induce the immunogenic substances including Ficolin-3, IL-1 and heat shock protein and regulate the immune cells by mediating the Th1/Th2 ratio, increasing Th17 cells, etc. On the other hand, RFA treatment can lead to tumor immune microenvironment reconstruction, increasing the proportion of functional T cells and upregulate PD-1 in T cells in distant tumors without RFA. This combined strategy has the ability to enhance the anti-tumor immune response through synergies, significantly reduce the risk of recurrence and improve survival.

CONCLUSIONS

RFA combined with immunotherapy yields a good synergistic effect: it can further strengthen anti-tumor response, delay distant tumor growth, reduce tumor recurrence and metastasis, providing new options for HCC systemic treatment.

Upregulation of EFCAB7 after radiofrequency ablation promoting hepatocellular carcinoma metastasis and survival by regulating PARK7

BACKGROUND

Radiofrequency ablation (RFA) is an established treatment for unresectable and early-stage hepatocellular carcinoma (HCC). However, in some cases, residual tumor cells undergo malignant transformation following RFA. The molecular mechanisms underlying this phenomenon remain poorly understood. EFCAB7, a member of the EF-hand structure family, is of particular interest due to its association with oncogenesis. Nevertheless, the role of EFCAB7 in oncogenesis remains unclear.

METHODS

Gene expression level of EFCAB7 in HCC tissues before and after RFA was measured, while in vitro and in vivo experiments were proposed for exploring the roles of EFCAB7 in tumor cell proliferation and metastasis. Mass spectrometry and CO-IP were adopted to validate the interaction between PARK7 and EFCAB7. Finally, PARK7 in EFCAB7 silencing cells was overexpressed and different functions were measured in vitro to determine regulation between two genes.

RESULTS

EFCAB7 showed increased expression after RFA in patient samples and EFCAB7 expression correlated with poor prognosis in HCC patients from the TCGA database. Then, EFCAB7 promoted HCC tumor cell proliferation and metastasis while inhibiting apoptosis. Furthermore, Mass spectrometry and Co-IP experiments revealed a direct interaction between EFCAB7 and PARK7. Finally, when we overexpressed PARK7 in EFCAB7 knockdown tumor cells, it rescued proliferation and metastasis, indicating a functional relationship between these two genes.

CONCLUSIONS

EFCAB7 might be a core contributor to HCC cells' malignant transformation after RFA and could be a potential novel target to provide a therapeutic strategy for the prevention of recurrence after RFA in HCC.

Pulsed Electric Field Ablation versus Radiofrequency Thermal Ablation in Murine Breast Cancer Models: Anticancer Immune Stimulation, Tumor Response, and Abscopal Effects

PURPOSE

To compare the immune response and survival after size-matched radiofrequency (RF) ablation and a proprietary form of pulsed electric field (PEF) ablation in murine tumors.

MATERIAL AND METHODS

Orthotopically inoculated EMT6 or 4T1 murine tumors received sham, RF ablation, or PEF ablation. 4T1 tumor ablations included subgroups with intraperitoneal checkpoint inhibition immunotherapy (αPD-1). Blood was collected for cytokine profiling and flow cytometry. Tumor size was measured and survival was monitored. Tumor samples were processed for histology, immunohistochemistry, flow cytometry, and cytokine profiling. Lungs were collected from 4T1-bearing mice for hematoxylin and eosin histology to assess metastatic spread and abscopal effect induced by ablation.

RESULTS

PEF elicited distinct immunomodulatory effects, with clear differences in serum and tumor cytokine profiles compared with RF ablation, including intratumoral downregulation of vascular endothelial growth factor, hypoxia-inducible factor 1α, c-MET, interleukin-10, Ki67, and tumor necrosis factor-α (all P < .05). PEF increased innate immune activation, with enhanced recruitment of dendritic cells, M1 macrophages, and natural killer cells coupled with a reduction in M2 macrophages and myeloid-derived suppressor cells (all P < .05). Concurrently, PEF strengthened adaptive immunity compared with RF ablation, characterized by increased antigen-specific T cells and decreased regulatory T cells (all P < .05). PEF stalled tumor growth and increased survival at the end of the study (≥4× versus RFA). Finally, PEF promoted an abscopal effect of clearing metastases in the lungs, which was stronger in combination with αPD-1 than with PEF alone.

CONCLUSIONS

The proprietary form of PEF used in this study evoked a preferential immunostimulatory profile versus RF ablation thermal ablation in mice, with implications for enhancing the therapeutic effectiveness of checkpoint inhibition immunotherapy for immunotherapy-unresponsive tumors.

A Trinity Nano-Vaccine System with Spatiotemporal Immune Effect for the Adjuvant Cancer Therapy after Radiofrequency Ablation

Cancer vaccine gains great attention with the advances in tumor immunology and nanotechnology, but its long-term efficacy is restricted by the unsustainable immune activity after vaccination. Here, we demonstrate the vaccine efficacy is negatively correlated with the tumor burden. To maximum the vaccine-induced immunity and prolong the time-effectiveness, we design a priming-boosting vaccination strategy by combining with radiofrequency ablation (RFA), and construct a bisphosphonate nanovaccine (BNV) system. BNV system consists of nanoparticulated bisphosphonates with dual electric potentials (BNV(+&-)), where bisphosphonates act as the immune adjuvant by blocking mevalonate metabolism. BNV(+&-) exhibits the spatial and temporal heterogeneity in lymphatic delivery and immune activity. As the independent components of BNV(+&-), BNV(-) is drained to the lymph nodes, and BNV(+) is retained at the injection site. The alternately induced immune responses extend the time-effectiveness of antitumor immunity and suppress the recurrence and metastasis of colorectal cancer liver metastases after RFA. As a result, this trinity system integrated with RFA therapy, bisphosphonate adjuvant, and spatiotemporal immune effect provides an orientation for the sustainable regulation and precise delivery of cancer vaccines.

Combinatory local ablation and immunotherapies for hepatocellular carcinoma: Rationale, efficacy, and perspective

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Local ablation, such as radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation, etc., are well established in elimination and control of HCC. However, high recurrence rate after local ablation remains the biggest challenge for HCC management. Novel and effective therapeutic strategies to improve long-term survival are urgently needed. Accumulating studies have reported the role of ablation in modulating the tumor signaling pathway and the immune microenvironment to both eliminate residual/metastatic tumor and promote tumor progression. Ablation has been shown to elicit tumor-specific immune responses by inducing massive cell death and releasing tumor antigen. Immunotherapies that unleash the immune system have the potential to enhance the anti-tumor immunity induced by ablation. Multiple combinatory strategies have been explored in preclinical and clinical studies. In this review, we comprehensively summarize the latest progress on different mechanisms underlying the effects of ablation on tumor cells and tumor microenvironment. We further analyze the clinical trials testing the combination of ablation and immunotherapies, and discuss the possible role of immunomodulation to boost the anti-tumor effects of ablation and prevent HCC recurrence.

An Overview of Hepatocellular Carcinoma After Insufficient Radiofrequency Ablation

Radiofrequency ablation (RFA) is a commonly used treatment for hepatocellular carcinoma (HCC), however, various complex conditions in clinical practice may lead to insufficient radiofrequency ablation (IRFA), allowing residual HCC to survive. In clinical practice and laboratory models, IRFA plays an important role in rapid tumor progression. Therefore, targeting the residual HCC and avoiding IRFA were worthwhile methods. A deeper understanding of IRFA is required; IRFA contributes to the improvement of proliferative activity, migration rates, and invasive capacity, and this may be due to the involvement of multiple complex processes or proteins, including epithelial mesenchymal transitions (EMTs), cancer stem cells (CSCs), autophagy, heat shock proteins (HSPs), changes of non-tumor cells and extracellular matrix, altered immune microenvironment, hypoxia-inducible factors (HIFs), growth factors, epigenetic alterations, and metabolic reprogramming. We focus on the processes of the above mechanisms and possible therapeutic approach, with a review of the literature. Additionally, we recapitulated the construction methods of various experimental models of IRFA (in vivo and in vitro).

Combination of Ablation and Immunotherapy for Hepatocellular Carcinoma: Where We Are and Where to Go

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and is increasing in incidence. Local ablative therapy plays a leading role in HCC treatment. Radiofrequency (RFA) is one of the first-line therapies for early local ablation. Other local ablation techniques (e.g., microwave ablation, cryoablation, irreversible electroporation, phototherapy.) have been extensively explored in clinical trials or cell/animal studies but have not yet been established as a standard treatment or applied clinically. On the one hand, single treatment may not meet the needs. On the other hand, ablative therapy can stimulate local and systemic immune effects. The combination strategy of immunotherapy and ablation is reasonable. In this review, we briefly summarized the current status and progress of ablation and immunotherapy for HCC. The immune effects of local ablation and the strategies of combination therapy, especially synergistic strategies based on biomedical materials, were discussed. This review is hoped to provide references for future researches on ablative immunotherapy to arrive to a promising new era of HCC treatment.