Effects of tumor vaccine expressing Granulocyte-Macrophage Colony Stimulating Factor and interleukin-18 fusion on cancer cells and its possible application for cancer immunotherapy

Bioengineering strategies to enhance the interleukin-18 bioactivity in the modern toolbox of cancer immunotherapy

Cytokines are the first modern immunotherapeutic agents used for activation immunotherapy. Interleukin-18 (IL-18) has emerged as a potent anticancer immunostimulatory cytokine over the past three decades. IL-18, structurally is a stable protein with very low toxicity at biological doses. IL-18 promotes the process of antigen presentation and also enhances innate and acquired immune responses. It can induce the production of proinflammatory cytokines and increase tumor infiltration of effector immune cells to revert the immunosuppressive milieu of tumors. Furthermore, IL-18 can reduce tumorigenesis, suppress tumor angiogenesis, and induce tumor cell apoptosis. These characteristics present IL-18 as a promising option for cancer immunotherapy. Although several preclinical studies have reported the immunotherapeutic potential of IL-18, clinical trials using it as a monotherapy agent have reported disappointing results. These results may be due to some biological characteristics of IL-18. Several bioengineering approaches have been successfully used to correct its defects as a bioadjuvant. Currently, the challenge with this anticancer immunotherapeutic agent is mainly how to use its capabilities in a rational combinatorial therapy for clinical applications. The present study discussed the strengths and weaknesses of IL-18 as an immunotherapeutic agent, followed by comprehensive review of various promising bioengineering approaches that have been used to overcome its disadvantages. Finally, this study highlights the promising application of IL-18 in modern combinatorial therapies, such as chemotherapy, immune checkpoint blockade therapy, cell-based immunotherapy and cancer vaccines to guide future studies, circumventing the barriers to administration of IL-18 for clinical applications, and bring it to fruition as a potent immunotherapy agent in cancer treatment.

Pin1 promotes pancreatic cancer progression and metastasis by activation of NF-κB-IL-18 feedback loop

Objectives

Accumulated evidence suggests that Pin1 contributes to oncogenesis of diverse cancers. However, the underlying mechanism of oncogenic function of Pin1 in PDAC requires further exploration.

Materials and Methods

IHC was performed using PDAC tissues. Western blot, PCR, immunofluorescence and transwell were performed using cell lines. GSEA were applied for possible downstream pathways. ChIP assay and dual luciferase were used for assessment of transcriptional activity.

Results

Both Pin1 and IL‐18 levels are increased in primary PDAC tissues and that their levels are positively correlated. High expression of IL‐18 is a predictor of poor prognoses. Pin1 promoted pancreatic cancer cell proliferation and motility by increasing IL‐18 expression, while Pin1 knockdown also inhibited the tumour‐promoting effect of IL‐18. Both Pin1 and IL‐18 could enhance the NFκB activity in pancreatic cancer cells. When bound to the p65 protein, Pin1 promoted p65 phosphorylation and its nuclear translocation. In the nucleus, Pin1 and p65 simultaneously bound to the IL‐18 promoter and enhanced IL‐18 transcription. In addition, recruitment of p65 to the IL‐18 promoter was decreased in Pin1‐silenced cells.

Conclusions

Our study improves the understanding of Pin1 in tumour‐promoting inflammation in PDAC, which is a hallmark of cancer; Pin1 interacted with p65 in PDAC and enhanced NF‐κB signalling and downstream transcriptional activation of IL‐18, with increased IL‐18 continuously activating NF‐κB signalling, which then forms a positive feedback loop.

Interleukin-18 expression in oral squamous cell carcinoma: its role in tumor cell migration and invasion, and growth of tumor cell xenografts

Oral squamous cell carcinoma (OSCC) is one of the most common head and neck malignancies. Advanced stages of the disease are associated with poor survival, highlighting a need for new treatment modalities. We previously showed that the proinflammatory cytokine interleukin‐18 (IL‐18) has a tumor suppressive role in OSCC. Here, we investigated the effects of IL‐18 on proliferation, migration, and invasion of OSCC cells ex vivo and in vitro, and in nude mouse xenografts. We report that expression of tankyrase 2 (TNKS2), β‐catenin, and N‐cadherin was higher in tumor cells than in normal mucosae, whereas the expression of IL‐18 and E‐cadherin was higher in normal than in tumor tissues. Elevated expression of IL‐18 (P < 0.01) and E‐cadherin (P = 0.034) was associated with tumor differentiation, whereas expression of TNKS2 (P < 0.01), β‐catenin (P = 0.012), and N‐cadherin (P < 0.01) was associated with tumor de‐differentiation. Furthermore, compared with the vector control, IL‐18 overexpression promoted tumor cell migration and invasion (P < 0.01), but inhibited growth of tumor cell xenografts (P < 0.05). At the protein level, expression levels of IL‐18 (P < 0.01), TNKS2 (P = 0.045), β‐catenin (P = 0.028), and N‐cadherin (P = 0.068) were upregulated in tumor cells after IL‐18 overexpression compared with those of the vector control mice, whereas expression levels of E‐cadherin (P = 0.045) were decreased. In conclusion, our data suggest that IL‐18 overexpression induces oral SCC cell invasion and metastasis by promoting the tumor cell epithelial–mesenchymal transition via the Wnt/β‐catenin signaling pathway.