Untargeted metabolomics profiling in a mouse model of lung cancer treated with thermal ablation

Cryoablation plus chemotherapy regimen enhance anti-tumor immune response in a mouse model of Lewis lung cancer

BACKGROUND

Cryoablation (cryo) is a local anti-tumor method and activation of immunity is one of its mechanisms, but it is affected by many factors. Numerous studies have proved that combination therapy based on cryo can activate immunity more effectively and synergistically. Cryo combined with chemotherapy(chemo) has been proven to improve the quality of life and prolong survival of tumor patients, but the immune effect is still unclear.

METHODS

C57B/L6 mouse lung cancer subcutaneous transplanted tumor model was established and sacrificed at two time points after intervention. We observed the effects of cryo + chemo on survival time, tumor growth, and dynamic changes of immune cells and cytokines.

RESULTS

Cryo + chemo could not only significantly prolong the survival period of mice, inhibit tumor growth and reduce the proliferation activity of tumor cells, but also promote immune response more effectively. Cryo + chemo could increase the number of CD4+ T cells both in spleen and tumor microenvironment, decrease the infiltration of Treg cells in the tumor microenvironment. Besides, cryo + chemo could increase the expression levels of IL-2 and IFN-γ, and reduce the levels of TGF-β. However, it is worth noting that the immune-promoting effect gradually decreases over time.

CONCLUSIONS

Cryo + chemo can effectively inhibit the growth of lung cancer, prolong the survival period and activate the immune response, providing a theoretical basis for the combined treatment. How to maintain the immune response for a long time is the next problem to be solved.

Cryo-Nanocatalyst Enhances Therapeutic Efficacy of Cryo-Immunotherapy through Necroptosis and Local Delivery of Programmed Death-Ligand 1 Inhibitors

Combining cryoablation and immunotherapy presents a promising approach to revert immunosuppressive responses to solid tumors. However, challenges such as postablated residual tumors and insufficient immune activity contribute to recurrence after cryo-immunotherapy. Herein, we investigated metallic supra-structured cryo-nanocatalyst (MSCN), which features numerous ice nucleation sites and interspace loading of therapeutic agents. MSCN elevates the freezing point and enhances ice nucleation, facilitating effective ice formation during cryotreatment. MSCN-loaded tumor cells showed a 2-fold increase in cryo-cytotoxicity and undergo osmotic-related cell damage, primarily necroptosis rather than other regulated cell death mechanisms. In prostate cancer models, RNA sequencing reveals that MSCN-cryoablation promoted antitumor inflammatory pathways, including necroptosis, compared to cryoablation alone. Additionally, following programmed death-ligand 1 (PD-L1) upregulation postcryoablation, synergistic effects with PD-L1 blockade were confirmed. Given the interspace of MSCN for aPD-L1 loading, we compared the intratumoral delivery of PD-L1 blockade against systemic injection. Enhanced necrosis and necroptosis from MSCN-cryoablation and PD-L1 blockade effectively eradicated tumors and triggered antitumor and memory immune responses locally and systemically. Lastly, a spatial landscape of tumor-infiltrating immune cells was analyzed to gain insight into heterogeneous tumor responses, leading to the limitations of conventional focal ablation techniques. Our findings highlight the potential of advanced cryo-immunotherapy using cryo-nanocatalysis to promote ice formation and necroptosis, stimulating antitumor immunogenic responses.

Synergetic Thermal Therapy for Cancer: State-of-the-Art and the Future

As a safe and minimal-invasive modality, thermal therapy has become an effective treatment in cancer treatment. Other than killing the tumor cells or destroying the tumor entirely, the thermal modality results in profound molecular, cellular and biological effects on both the targeted tissue, surrounding environments, and even the whole body, which has triggered the combination of the thermal therapy with other traditional therapies as chemotherapy and radiation therapy or new therapies like immunotherapy, gene therapy, etc. The combined treatments have shown encouraging therapeutic effects both in research and clinic. In this review, we have summarized the outcomes of the existing synergistic therapies, the underlying mechanisms that lead to these improvements, and the latest research in the past five years. Limitations and future directions of synergistic thermal therapy are also discussed.