Synergism between cryoablation and GM-CSF: enhanced immune function of splenic dendritic cells in mice with glioma. Neuroreport. 2015;26:346-353. [PMID: 25735009 DOI: 10.1097/wnr.0000000000000351]

Interventional Oncology and Immuno-Oncology: Current Challenges and Future Trends

Personalized cancer treatments help to deliver tailored and biologically driven therapies for cancer patients. Interventional oncology techniques are able to treat malignancies in a locoregional fashion, with a variety of mechanisms of action leading to tumor necrosis. Tumor destruction determines a great availability of tumor antigens that can be recognized by the immune system, potentially triggering an immune response. The advent of immunotherapy in cancer care, with the introduction of specific immune checkpoint inhibitors, has led to the investigation of the synergy of these drugs when used in combination with interventional oncology treatments. The aim of this paper is to review the most recent advances in the field of interventional oncology locoregional treatments and their interactions with immunotherapy.

An In Vitro Investigation into Cryoablation and Adjunctive Cryoablation/Chemotherapy Combination Therapy for the Treatment of Pancreatic Cancer Using the PANC-1 Cell Line

As the incidence of pancreatic ductal adenocarcinoma (PDAC) continues to grow, so does the need for new strategies for treatment. One such area being evaluated is cryoablation. While promising, studies remain limited and questions surrounding basic dosing (minimal lethal temperature) coupled with technological issues associated with accessing PDAC tumors and tumor proximity to vasculature and bile ducts, among others, have limited the use of cryoablation. Additionally, as chemotherapy remains the first-line of attack for PDAC, there is limited information on the impact of combining freezing with chemotherapy. As such, this study investigated the in vitro response of a PDAC cell line to freezing, chemotherapy, and the combination of chemotherapy pre-treatment and freezing. PANC-1 cells and PANC-1 tumor models were exposed to cryoablation (freezing insult) and compared to non-frozen controls. Additionally, PANC-1 cells were exposed to varying sub-clinical doses of gemcitabine or oxaliplatin alone and in combination with freezing. The results show that freezing to −10 °C did not affect viability, whereas −15 °C and −20 °C resulted in a reduction in 1 day post-freeze viability to 85% and 20%, respectively, though both recovered to controls by day 7. A complete cell loss was found following a single freeze below −25 °C. The combination of 100 nM gemcitabine (1.1 mg/m2) pre-treatment and a single freeze at −15 °C resulted in near-complete cell death (<5% survival) over the 7-day assessment interval. The combination of 8.8 µM oxaliplatin (130 mg/m2) pre-treatment and a single −15 °C freeze resulted in a similar trend of increased PANC-1 cell death. In summary, these in vitro results suggest that freezing alone to temperatures in the range of −25 °C results in a high degree of PDAC destruction. Further, the data support a potential combinatorial chemo/cryo-therapeutic strategy for the treatment of PDAC. These results suggest that a reduction in chemotherapeutic dose may be possible when offered in combination with freezing for the treatment of PDAC.

Argon-Helium Cryoablation for Cutaneous Squamous Cell Carcinoma in the Elderly

Cutaneous squamous cell carcinoma (cSCC) is a common type of malignant neoplasm in non-melanoma skin cancer (NMSC). Most cases of simple cSCC are considered curable by surgical removal of the lesion. However, clinical treatments for cSCC with medium- or large-sized lesions are difficult. Meanwhile, the effectiveness of the treatments is not guaranteed, especially for elderly patients, because of an intolerance to surgical resection or other adjuvant modalities. In such cases, safe and effective treatments with excellent aesthetic outcomes are urgently needed. In this study, we reported 6 elderly cSCC patients with medium- or large-sized lesions treated with argon-helium cryoablation. The average age of all 6 patients was 78 years (range 72-85 years). They were all diagnosed with cSCC with a median tumor size of 5.8 cm (range 2.5-15.5 cm) and dermal invasion. Complete ablation was achieved in all cases after a single ablation session (2 freeze-thaw cycles). Patients experienced mild pain and hemorrhage after ablation, but the symptoms were manageable. One patient developed infection and fever because of extensive necrosis of the tumor, which was eventually cured after treatment. All patients obtained good cosmetic outcomes, and their quality of life improved significantly. In the 5-year follow-up study, 4 patients were alive while 2 patients died of unrelated diseases 3 years after cryotherapy. None of the 6 patients had a recurrence. These results suggested the feasibility of argon-helium cryoablation as a novel therapeutic strategy for elderly cSCC with medium- or large-sized lesions.

Cryoablation reshapes the immune microenvironment in the distal tumor and enhances the anti-tumor immunity

As one of the local treatments, cryoablation plays an increasingly important role in the comprehensive treatment of malignant tumors with its advantages of less trauma, high reproducibility, and minimally invasive. Activation of anti-tumor immunity, another characteristic of cryoablation, has attracted more and more attention with the extensive application of immunotherapy. Unfortunately, the mechanism by which cryoablation enhances anti-tumor immunity is still unclear. In this study, we applied a multi-omics approach to investigate the effects of local cryoablation in the distal tumor microenvironment. The results revealed that large amounts of tumor antigens were released post-cryoablation, leading to a sterile inflammatory response in distant tumors. During this period, activated lysosome-related pathways result in over-expression of SNAP23 (Synaptosome associated protein 23) and STXBP2 (Syntaxin binding protein 2), activation of immune effector cells, suppression of the release of immunosuppressive factors, and finally enhancement of anti-tumor immunity, which shows a broad prospect in combined immunotherapy.

Thermal ablation in non-small cell lung cancer: a review of treatment modalities and the evidence for combination with immune checkpoint inhibitors

Lung cancer is the leading cause of cancer death worldwide, with approximately 1.6 million cancer related deaths each year. Prognosis is best in patients with early stage disease, though even then five-year survival is only 55% in some groups. Median survival for advanced non-small cell lung cancer (NSCLC) is 8–12 months with conventional treatment. Immune checkpoint inhibitor (ICI) therapy has revolutionised the treatment of NSCLC with significant long-term improvements in survival demonstrated in some patients with advanced NSCLC. However, only a small proportion of patients respond to ICI, suggesting the need for further techniques to harness the potential of ICI therapy. Thermal ablation utilizes the extremes of temperature to cause tumour destruction. Commonly used modalities are radiofrequency ablation (RFA), cryoablation and microwave ablation (MWA). At present thermal ablation is reserved for curative-intent therapy in patients with localized NSCLC who are unable to undergo surgical resection or stereotactic ablative body radiotherapy (SABR). Limited evidence suggests that thermal ablative modalities can upregulate an anticancer immune response in NSCLC. It is postulated that thermal ablation can increase tumour antigen release, which would initiate and upregulated steps in the cancer immunity cycle required to elicit an anticancer immune response. This article will review the current thermal ablative techniques and their ability to modulate an anti-cancer immune response with a view of using thermal ablation in conjunction with ICI therapy.

The Cryo-immunologic effect: A therapeutic advance in the treatment of glioblastomas?

The immunotherapy of cerebral glioblastoma has become a hot topic. Immune checkpoint blockade antibodies have progressively acquired a role in the management of malignant tumors. A multimodal approach using surgery, radiotherapy, chemotherapy in combination with immunotherapy represent a potent weapon against glioblastomas. In parallel, clinical applications of cryotherapy-freezing tumors based on repetition of rapid freeze-slow thaw cycle-for various cancers such as skin, lung, breast, esophagus, hepatic, kidney, prostate and bone tumors were developed. The future immunomodulatory approaches might be combined with brain tumors cryoablation to increase the cryoimmune response. The objective of this study was to analyze from the literature the relationship between cerebral cryosurgery and immunomodulation using PRISMA method. The animals' studies demonstrate the dendritic cells maturation and activation with the enhancement of antigen-presenting function after cryotherapy suggesting the potential usefulness of the association of cryotherapy and immunomodulator in the management of gliomas.

Antitumour dendritic cell vaccination in a priming and boosting approach

Mobilizing antitumour immunity through vaccination potentially constitutes a powerful anticancer strategy but has not yet provided robust clinical benefits in large patient populations. Although major hurdles still exist, we believe that currently available strategies for vaccines that target dendritic cells or use them to present antitumour antigens could be integrated into existing clinical practice using prime-boost approaches. In the priming phase, these approaches capitalize on either standard treatment modalities to trigger in situ vaccination and release tumour antigens or vaccination with dendritic cells loaded with tumour lysates or patient-specific neoantigens. In a second boost phase, personalized synthetic vaccines specifically boost T cells that were triggered during the priming phase. This immunotherapy approach has been enabled by the substantial recent improvements in dendritic cell vaccines. In this Perspective, we discuss these improvements, highlight how the prime-boost approach can be translated into clinical practice and provide solutions for various anticipated hurdles.

Genomic analysis of the prognostic value of colony-stimulating factors (CSFs) and colony-stimulating factor receptors (CSFRs) across 24 solid cancer types

Background

The prognostic roles of granulocyte-/granulocyte-macrophage colony-stimulating factor (G-/GM-CSF) and its receptors (CSFRs) from the genomic perspective remain controversial. The aim of our study was to evaluate their prognostic value in multiple cancer types by analyzing omics data.

Methods

The omics data of G-/GM-CSF and receptors were obtained from the cBioportal database. Cutoff values were determined by X-tile. Overall survival (OS) was assessed by Kaplan–Meier curves. Differentially expressed genes (DEGs) and common regulated genes were analyzed using R software and Venny 2.1.0, while enrichment pathway analyses were performed by Metascape.

Results

A comprehensive mRNA analysis was performed in 8,565 patients across 24 cancer types. The combination subgroup of CSF2 and its receptors with high expression and favorable prognosis was associated with the activation of immune-related pathways, while the subgroup with unfavorable prognosis was associated with the activation of inflammatory and cellular pathways. As for the combination subgroup of CSF3 and its receptor, the high expression and poor prognosis subgroup was accompanied by the activation of inflammation and signaling transduction pathways.

Conclusions

The prognostic value of CSFs and CSFRs are cancer-type dependent. Therefore, personalized risk stratification based on CSF and CSFR pathway should be considered for cancer patients.

The future of cryoablation: An abscopal effect

Cryoablation has become a popular modality to treat a variety of malignant tumors in solid organs and soft tissues. In the future, the use of cryoablation should focus on its abscopal effect. The present review discusses the increased immune response triggered by cryoablation alone or by cryoablation combined with immunotherapies, which can improve the immune response and limit immunosuppression. First, cryoablative techniques should be improved to increase the area of necrosis and reduce the area of apoptosis. Second, cryoablation should be combined with immunotherapies, for example, cyclophosphamide, natural killer cells, granulocyte monocyte colony stimulating factor (GM-CSF), cytotoxic T lymphocyte-associated antigen (CTLA)-4, and programmed death receptor 1 (PD)-1 inhibitors. Cryoablation could also be combined with Hydrogen gas molecules, which were shown recently to stimulate peroxisome proliferator activated receptor gamma coactivator (PGC)-1α, thereby promoting mitochondrial function, which might rescue exhausted CD8⁺ T cells, leading to prolonged progression-free survival and overall survival of patients with advanced colorectal cancer.

Postablation Immune Microenvironment: Synergy between Interventional Oncology and Immuno-oncology

Current tumor thermal ablation techniques rely on extreme temperatures to induce irreversible cellular injury and coagulative tissue necrosis. Ablation-induced cellular injury or death releases cancer neoantigens and activates the cancer-immunity cycle, potentially generating tumor-specific immune effectors. However, multiple negative regulatory modulators exist at each step of the cycle, mitigating meaningful and therapeutic anticancer effect provided by the immune system. Recent studies have focused on the introduction and testing of adjuvant immunotherapy combined with ablation to synergistically shift the equilibrium out of inhibitory immune modulation. This article reviews the immune microenvironment in relation to image-guided ablation techniques and discusses current and upcoming novel strategies to take advantage of antitumor immunity.

Characterization of CSF2A fusion gene and its effect on Epstein-Barr virus-positive tumor cells

We build the latent membrane protein gene latent membrane protein 2A (LMP2A) and the granulocyte-macrophase colony-stimulating factor (GM-CSF) gene fusion gene (CSF2A) and discuss how the CSF2A fusion protein influenced the proliferation and apoptosis of Epstein-Barr virus-positive (EBV⁺ ) tumor cells. Reverse-transcription polymerase chain reaction (RT-PCR) method was used to amplify the LMP2A gene and GM-CSF gene fragments, respectively, according to the principle of overlap extension in the coding (Gly4Ser)₃ polypeptide gene fragments of DNA restructured under the connection. The CSF2A gene could be connected with the pIRES2-enhanced green fluorescent protein vector by recombinant DNA technology and identified by enzyme electrophoresis analysis and DNA sequencing. Then, the recombinant vector was transfected into dendritic cells (DCs); RT-PCR and Western blot analysis were used for testing the CSF2A gene messenger RNA and protein expression. The impacts of CSF2A on the proliferation and apoptosis of EBV⁺ tumor cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Hochest 33342 staining. We successfully obtained the recombinant vector named pIRES2-CSF2A. The expression of CSF2A could be detected by transfecting pIRES2-CSF2A into DCs. The DCs were cocultured with T lymphocytes and then acted on the EBV⁺ CNE2 nasopharyngeal carcinoma cells. MTT assay showed that the inhibiting effect of CSF2A obviously increased and the time dependency (**P < 0.01, *P < 0.05) also existed. Hochest 33342 staining showed apoptosis morphological changes of cells in nucleus staining and generated the apoptotic body. Apoptosis cells of the pIRES2-CSF2A group increased significantly at 48 hours. The results showed that the pIRES2-CSF2A recombinant vector was effectively transfected into DCs and the fusion gene CSF2A could promote EBV⁺ CNE2 cell apoptosis, laying the foundation for the specificity of EBV⁺ tumor targeting immune gene therapy in the future.

Observation of the effect of targeted therapy of 64-slice spiral CT combined with cryoablation for liver cancer

AIM

To observe the effect of targeted therapy with 64-slice spiral computed tomography (CT) combined with cryoablation for liver cancer.

METHODS

A total of 124 patients (142 tumors) were enrolled into this study. According to the use of dual-slice spiral CT or 64-slice spiral CT as a guide technology, patients were divided into two groups: dual-slice group (n = 56, 65 tumors) and 64-slice group (n = 8, 77 tumors). All patients were accepted and received targeted therapy by an argon-helium superconducting surgery system. The guided scan times of the two groups was recorded and compared. In the two groups, the lesion ice coverage in diameter of ≥ 3 cm and < 3 cm were recorded, and freezing effective rate was compared. Hepatic perfusion values [hepatic artery perfusion (HAP), portal vein perfusion (PVP), and the hepatic arterial perfusion index (HAPI)] of tumor tissues, adjacent tissues and normal liver tissues at preoperative and postoperative four weeks in the two groups were compared. Local tumor changes were recorded and efficiency was compared at four weeks post-operation. Adverse events were recorded and compared between the two groups, including fever, pain, frostbite, nausea, vomiting, pleural effusion and abdominal bleeding.

RESULTS

Guided scan times in the dual-slice group was longer than that in the 64-slice group (t = 11.445, P = 0.000). The freezing effective rate for tumors < 3 cm in diameter in the dual-slice group (81.58%) was lower than that in the 64-slice group (92.86%) (χ² = 5.707, P = 0.017). The HAP and HAPI of tumor tissues were lower at four weeks post-treatment than at pre-treatment in both groups (all P < 0.05), and those in the 64-slice group were lower than that in the dual-slice group (all P < 0.05). HAP and PVP were lower and HAPI was higher in tumor adjacent tissues at post-treatment than at pre-treatment (all P < 0.05). Furthermore, the treatment effect and therapeutic efficacy in the dual-slice group were lower than the 64-slice group at four weeks post-treatment (all P < 0.05). Moreover, pleural effusion and intraperitoneal hemorrhage occurred in patients in the dual-slice group, while no complications occurred in the 64-slice group (all P < 0.05).

CONCLUSION

64-slice spiral CT applied with cryoablation in targeted therapy for liver cancer can achieve a safe and effective freezing treatment, so it is worth being used.