Upregulation of IL-6 is involved in moderate hyperthermia induced proliferation and invasion of hepatocellular carcinoma cells

Radiofrequency ablation: mechanisms and clinical applications

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

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.

Differential cytokine and chemokine expression after ablation vs. resection in colorectal cancer liver metastasis

Background

Surgical resection remains the main curative treatment for colorectal liver metastases (CRLM). Radiofrequency ablation (RFA) is increasingly employed for small, deep lying or otherwise inoperable lesions. However, RFA can induce pro-tumorigenic effects on residual tumor cells, hereby possibly promoting tumor recurrence. Contrastingly, post-RFA tumor debris as an antigen source can also generate anti-cancer immune responses. Utilizing this, current studies on combining RFA with immune therapy appear promising. Here, in an attempt to shed light on this controversy, cytokines involved in inflammation, (lymph)angiogenesis, immune cell recruitment and tumor cell invasion were investigated post-RFA versus post-resection in CRLM patients.

Methods

Cytokine and chemokine serum levels pre-operation, 4 h and 24 h post-operation were analyzed in CRLM patients undergoing RFA (n = 8) or partial hepatectomy (n = 9) using Multiplex immunoassays. Statistical analyses were performed between as well as within individual intervention groups.

Results

Post-RFA, significantly increased levels of acute phase proteins SAA1 and S100A8, IL-6, IL-1Ra, MIP3b (CCL19) and MMP9 were observed along with decreases in Fibronectin, MCP-1 (CCL2), and Tie-2. Post-resection, increased levels of PDGFbb, I309 (CCL1), Apelin, MIF, IL-1b and TNFα were seen. All p-values <0.05.

Conclusion

Pro-inflammatory responses mediated by different cytokines were seen after both RFA and resection, possibly influencing residual tumor cells and tumor recurrence. As both ablation and resection trigger inflammation and immune cell recruitment (albeit via distinct mechanisms), these data suggest that further research may explore combining immune therapy with not only RFA but also resection.

Key message

Analysis of patients' serum after radiofrequency ablation versus resection of colorectal liver metastases (CRLM) showed that these interventions trigger inflammation and immune cell recruitment, via different cyto- and chemokine pathways. This suggests a possible future strategy of combining immune therapy with not only ablative techniques but also with resection of CRLM.

The immune response of hepatocellular carcinoma after locoregional and systemic therapies: The available combination option for immunotherapy

Hepatocellular carcinoma (HCC) is associated with a highly heterogeneous immune environment that produces an immune response to various locoregional treatments (LRTs), which in turn affects the effectiveness of immunotherapy. Although LRTs still dominate HCC therapies, 50-60% of patients will ultimately be treated with systemic therapies and might receive those treatments for the rest of their life. TACE, SIRT, and thermal ablation can dramatically increase the immunosuppressive state of HCC, a condition that can be addressed by combination with immunotherapy to restore the activity of lymphocytes and the secretion of cellular immune factors. Immune treatment with locoregional and systemic treatments has dramatically changed the management of HCC. In this review, we examine the research on the changes in the immune microenvironment after locoregional or systemic treatment. We also summarize the regulation of various immune cells and immune factors in the tumor microenvironment and discuss the different infiltration degrees of immune cells and factors on the prognosis of HCC to better compare the efficacy between different treatment methods from the perspective of the tumor microenvironment. This information can be used to help develop treatment options for the upcoming new era of HCC treatment in the future.

GSDME has prognostic and immunotherapeutic significance in residual hepatocellular carcinoma after insufficient radiofrequency ablation

BACKGROUND

Heat stress can induce programmed cell death (PCD). Pyroptosis is a gasdermin-mediated PCD. This study hypothesized that insufficient radiofrequency ablation (IRFA) induced pyroptosis in hepatocellular carcinoma (HCC) and investigated its underlying mechanism and clinical significance.

METHODS

Thermostatic water bath was used to stimulate IRFA in vitro. Cell viability was assessed by MTT assay. IL-1β and HMGB1 were measured by ELISA assay. LDH level was measured by LDH cytotoxicity detection kit. Permeability of cell membrane was assessed by Hoechst33342/PI fluorescence staining. RNA expression was evaluated by qRT-PCR, and protein was assessed by Western Blotting or immunofluorescence or immunohistochemistry. Gene expression with clinicopathological characteristics from HCC patients treated by RFA were analyzed for associations between GSDME expression and prognosis.

RESULTS

Our study revealed that IRFA induced pyroptosis in HCCLM3 and HepG2 cells. GSDME, rather than GSDMD, was cleaved in heat stress-induced pyroptosis in HCCLM3 and HepG2 cells due to caspase-3 activation. However, GSDME overexpression promoted HCC growth in vivo and predicted poor PFS and OS in HCC patients treated by RFA. Heat stress modulated gene expression related to PD-L1 signaling and caspase inhibitors inhibited heat-induced PD-L1 expression in residual HCC after IRFA. Gsdme overexpression caused resistance to PD-L1 inhibitor in residual HCC after IRFA by increasing infiltrating of CD3+PD-1+ or CD3+CTLA-4+ exhausted T cells.

CONCLUSIONS

This study indicated that GSDME could serve as a potential prognostic biomarker and help to prescribe personalized sequential immunotherapy for HCC patients receiving RFA.

Mechanisms and therapeutic strategies to combat the recurrence and progression of hepatocellular carcinoma after thermal ablation

Thermal ablation (TA), including radiofrequency ablation (RFA) and microwave ablation (MWA), has become the main treatment for early-stage hepatocellular carcinoma (HCC) due to advantages such as safety and minimal invasiveness. However, HCC is prone to local recurrence, with more aggressive malignancies after TA closely related to TA-induced changes in epithelial-mesenchymal transition (EMT) and remodeling of the tumor microenvironment (TME). According to many studies, various components of the TME undergo complex changes after TA, such as the recruitment of innate and adaptive immune cells, the release of tumor-associated antigens (TAAs) and various cytokines, the formation of a hypoxic microenvironment, and tumor angiogenesis. Changes in the TME after TA can partly enhance the anti-tumor immune response; however, this response is weak to kill the tumor completely. Certain components of the TME can induce an immunosuppressive microenvironment through complex interactions, leading to tumor recurrence and progression. How the TME is remodeled after TA and the mechanism by which the TME promotes HCC recurrence and progression are unclear. Thus, in this review, we focused on these issues to highlight potentially effective strategies for reducing and preventing the recurrence and progression of HCC after TA.

Amplifying cancer treatment: advances in tumor immunotherapy and nanoparticle-based hyperthermia

In the quest for cancer treatment modalities with greater effectiveness, the combination of tumor immunotherapy and nanoparticle-based hyperthermia has emerged as a promising frontier. The present article provides a comprehensive review of recent advances and cutting-edge research in this burgeoning field and examines how these two treatment strategies can be effectively integrated. Tumor immunotherapy, which harnesses the immune system to recognize and attack cancer cells, has shown considerable promise. Concurrently, nanoparticle-based hyperthermia, which utilizes nanotechnology to promote selective cell death by raising the temperature of tumor cells, has emerged as an innovative therapeutic approach. While both strategies have individually shown potential, combination of the two modalities may amplify anti-tumor responses, with improved outcomes and reduced side effects. Key studies illustrating the synergistic effects of these two approaches are highlighted, and current challenges and future prospects in the field are discussed. As we stand on the precipice of a new era in cancer treatment, this review underscores the importance of continued research and collaboration in bringing these innovative treatments from the bench to the bedside.

The Synergistic Effect of Interventional Locoregional Treatments and Immunotherapy for the Treatment of Hepatocellular Carcinoma

Immunotherapy has remarkably revolutionized the management of advanced HCC and prompted clinical trials, with therapeutic agents being used to selectively target immune cells rather than cancer cells. Currently, there is great interest in the possibility of combining locoregional treatments with immunotherapy for HCC, as this combination is emerging as an effective and synergistic tool for enhancing immunity. On the one hand, immunotherapy could amplify and prolong the antitumoral immune response of locoregional treatments, improving patients' outcomes and reducing recurrence rates. On the other hand, locoregional therapies have been shown to positively alter the tumor immune microenvironment and could therefore enhance the efficacy of immunotherapy. Despite the encouraging results, many unanswered questions still remain, including which immunotherapy and locoregional treatment can guarantee the best survival and clinical outcomes; the most effective timing and sequence to obtain the most effective therapeutic response; and which biological and/or genetic biomarkers can be used to identify patients likely to benefit from this combined approach. Based on the current reported evidence and ongoing trials, the present review summarizes the current application of immunotherapy in combination with locoregional therapies for the treatment of HCC, and provides a critical evaluation of the current status and future directions.

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.

Insufficient ablation promotes the metastasis of residual non-small cell lung cancer (NSCLC) cells via upregulating carboxypeptidase A4

BACKGROUND

Thermal ablation is a potentially curative therapy for early-stage non-small cell lung cancer (NSCLC). Early recurrence after thermal ablation necessitates our attention.

METHODS

The invasion and migration abilities of NSCLC after sublethal heat stimulus were observed in vitro and in vivo. Sublethal thermal stimulus molecular changes were identified by RNA sequencing. A xenograft model of NSCLC with insufficient ablation was established to explore the epithelial-to-mesenchymal transition (EMT) and metastasis-related phenotypes alteration of residual tumors.

RESULTS

In vitro, the invasion and migration abilities of NSCLC cells were enhanced 72 h after 44 °C and 46 °C thermal stimulus. Epithelial-mesenchymal transition (EMT) phenotypes were also upregulated under these conditions. RNA sequencing revealed that the expression of carboxypeptidase A4 (CPA4) was significantly upregulated after thermal stimulus. Significant upregulation of CPA4 and EMT phenotypes was also found in the xenograft model of insufficient NSCLC ablation. The EMT process and invasion and migration abilities can be reversed by silencing CPA4.

CONCLUSIONS

This study demonstrates that sublethal heat stimulus caused by insufficient ablation can promote EMT and enhance the metastatic capacity of NSCLC. CPA4 plays an important role in these biological processes. Inhibition of CPA4 might be of great significance for improving early-stage NSCLC survival after ablation.

Inflammatory microenvironment of fibrotic liver promotes hepatocellular carcinoma growth, metastasis and sorafenib resistance through STAT3 activation

The pro-inflammatory and pro-fibrotic liver microenvironment facilitates hepatocarcinogenesis. However, the effects and mechanisms by which the hepatic fibroinflammatory microenvironment modulates intrahepatic hepatocellular carcinoma (HCC) progression and its response to systematic therapy remain largely unexplored. We established a syngeneic orthotopic HCC mouse model with a series of persistent liver injury induced by CCl4 gavage, which mimic the dynamic effect of hepatic pathology microenvironment on intrahepatic HCC growth and metastasis. Non-invasive bioluminescence imaging was applied to follow tumour progression over time. The effect of the liver microenvironment modulated by hepatic injury on sorafenib resistance was investigated in vivo and in vitro. We found that the persistent liver injury facilitated HCC growth and metastasis, which was positively correlated with the degree of liver inflammation rather than the extent of liver fibrosis. The inflammatory cytokines in liver tissue were clearly increased after liver injury. The two indicated cytokines, tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6), both promoted intrahepatic HCC progression via STAT3 activation. In addition, the hepatic inflammatory microenvironment contributed to sorafenib resistance through the anti-apoptotic protein mediated by STAT3, and STAT3 inhibitor S3I-201 significantly improved sorafenib efficacy impaired by liver inflammation. Clinically, the increased inflammation of liver tissues was accompanied with the up-regulated STAT3 activation in HCC. Above all, we concluded that the hepatic inflammatory microenvironment promotes intrahepatic HCC growth, metastasis and sorafenib resistance through activation of STAT3.

Hyperthermia Targeting the Tumor Microenvironment Facilitates Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have ushered in a new era of cancer therapy; however, ICIs are only effective in selective patients. The efficacy of ICIs is closely related to the tumor microenvironment. Fever for a long time was thought to directly regulate the immune response, and artificial “fever” from hyperthermia modulates the tumor immune microenvironment by providing danger signals with heat shock proteins (HSPs) as well as subsequent activation of immune systems. Encouraging results have been achieved in preclinical studies focused on potential synergetic effects by combining hyperthermia with ICIs. In this review, we summarized a cluster of immune-related factors that not only make hyperthermia a treatment capable of defending against cancer but also make hyperthermia a reliable treatment that creates a type I-like tumor microenvironment (overexpression of PD-L1 and enrichment of tumor infiltrating lymphocytes) in complementary for the enhancement of the ICIs. Then we reviewed recent preclinical data of the combination regimens involving hyperthermia and ICIs that demonstrated the combined efficacy and illustrated possible approaches to further boost the effectiveness of this combination.

Emerging Opportunities for Combining Locoregional Therapy with Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

PURPOSE OF REVIEW

Immunotherapy shows great promises in solid tumors. Locoregional therapy can promote systemic immune response in hepatocellular carcinoma (HCC). The combination of locoregional therapy and immune checkpoint inhibitors (ICIs) activates a synergistic effect that can enhance the potency of anti-tumor immunity. This review aims to summarize the underlying mechanisms of locoregional therapy combined with ICIs and their applications in clinical settings.

RECENT FINDINGS

The characteristics of high invasiveness and refractoriness of HCC are what limit the outcomes of treatments. Sorafenib provides an additional treatment option for extrahepatic spread and vascular invasion, making long-term survival possible for patients with advanced HCC to some degree. However, its shortcomings of low response rate and high toxicity result in limited applications in clinical practice. Immunotherapy is a promising emerging therapy with great prospect in HCC, but the self-tolerance of HCC constrains the effectiveness of ICIs. Consequently, the efficacy of single immunotherapy is unsatisfactory. Locoregional therapy can not only destroy primary tumors but also stimulate the release of neoplasm antigens to increase the efficiency of immune response in HCC. Locoregional therapy combined with ICIs may have an amplification effect on immune response. Locoregional therapy plays a vital role in stimulating anti-tumor immune response. The combination of locoregional therapy and ICIs has a synergistic effect on anti-tumor immunity.

Immune correlates of clinical benefit in a phase I study of hyperthermia with adoptive T cell immunotherapy in patients with solid tumors

Purpose: To characterize the T cell receptor (TCR) repertoire, serum cytokine levels, peripheral blood T lymphocyte populations, safety, and clinical efficacy of hyperthermia (HT) combined with autologous adoptive cell therapy (ACT) and either salvage chemotherapy (CT) or anti-PD-1 antibody in patients with previously treated advanced solid tumors.Materials and methods: Thirty-three (33) patients with ovarian, pancreatic, gastric, colorectal, cervical, or endometrial cancer were recruited into the following therapeutic groups: HT + ACT (n = 10), HT + ACT + anti-PD-1 inhibitor (pembrolizumab) (n = 11) and HT + ACT + CT (n = 12). Peripheral blood was collected to analyze TCR repertoire, measurements of cytokines levels and lymphocyte sub-populations before and after treatment.Results: The objective response rate (ORR) was 30% (10/33), including three complete responses (CR) (9.1%) and seven partial responses (PR) (21.2%) and a disease control rate (DCR = CR + PR + SD) of 66.7% (22 of 33). The most common adverse reactions, blistering, subcutaneous fat induration, local heat-related pain, vomiting and sinus tachycardia, were observed in association with HT. IL-2, IL-4, TNF-α, and IFN-γ levels in peripheral blood were significantly increased among the clinical responders (p < 0.05) while IL-6 and IL-10 were elevated among those with progressive disease (p < 0.05). Peripheral blood CD8⁺/CD28⁺ T cells increased (p = 0.002), while the CD4⁺/CD25⁺/CD127⁺Treg cells decreased after therapy (p = 0.012). TCR diversity was substantially increased among the clinical responders.Conclusions: Combining HT with ACT plus either CT or anti-PD-1 antibody was safe, generated clinical responses in previously treated advanced cancers, and promoted TCR repertoire diversity and favorable changes in serum IL-2, IL-4, TNF-α, and IFN-γ levels in clinical responders.

Silencing CDC25A inhibits the proliferation of liver cancer cells by downregulating IL‑6 in vitro and in vivo

Cell division cycle 25A (CDC25A) is a core regulator of the cell cycle that has a dual‑specific phosphatase activity, which is closely associated with the occurrence and development of a tumor, and is overexpressed in liver cancer. However, the molecular mechanism of CDC25A in the development of liver cancer remains unclear. The purpose of the present study was to further investigate the effect of CDC25A on cell proliferation in vitro and in vivo and to investigate whether an interaction exists between CDC25A and interleukin (IL)‑6 in liver cancer. An Affymetrix human gene expression profiling chip screened differentially expressed genes in HepG2 cells with silenced CDC25A and the IL‑6 signaling pathway was revealed to be significantly inhibited (P<0.05). In the present study, the effects of CDC25A on cell proliferation and migration were analyzed using cell cycle, MTT and Transwell assays. Reverse transcription‑quantitative PCR, western blot and immunohistochemistry analyses confirmed that silencing the CDC25A gene downregulated the expression of IL‑6 in HepG2 cells and the mRNA and protein expression of IL‑1β, mitogen‑activated protein kinase kinase kinase 14 (NIK) and nuclear factor‑κB (NF‑κB), which are regulatory molecules upstream of IL‑6. In addition, silencing CDC25A by short hairpin RNA inhibited the development of liver cancer xenograft tumor types in nude mice, and decreased the expression of IL‑1β, NIK, NF‑κB and IL‑6 in xenograft tumor types. In conclusion, silencing CDC25A significantly inhibited the proliferation of liver cancer cells in vitro and in vivo, potentially via an interaction with IL‑6 through the downregulation of the IL‑1β/NIK/NF‑κB signaling axis.