Gas Plasma Exposure of Glioblastoma Is Cytotoxic and Immunomodulatory in Patient-Derived GBM Tissue

Gas Plasma Technology and Immunogenic Cell Death: Implications for Chordoma Treatment

Cancer is the second-leading cause of death in developed societies. Specifically, cancers of the spine and brain come with significant therapeutic challenges. Chordomas are semi-malignant tumors that develop from embryonic residuals at the skull base (clival) or coccyx (sacral). Small tumor fragments can remain in the operation cavities during surgical resection, forming new tumor sites. This requires repeated surgeries or the application of proton-beam radiation and chemotherapy, which often do not lead to complete remission of the tumors. Hence, there is a need for novel therapeutic avenues that are not limited to killing visible tumors but can be applied after surgery to decrease chordoma recurrences. Reactive oxygen species (ROS) generated locally via novel medical gas plasma technologies are one potential approach to address this clinical problem. Previously, broad-spectrum free radicals generated by these cold physical plasmas operated at about body temperature were shown to oxidize cancer cells to the disadvantage of their growth and induce immunogenic cancer cell death (ICD), ultimately promoting anticancer immunity. This review outlines the clinical challenges of chordoma therapy, how medical gas plasma technology could serve as an adjuvant treatment modality, and potential immune-related mechanisms of action that could extend the longevity of gas plasma therapy beyond its acute local tissue effects.

Prognostic value of CTF1 in glioma and its role in the tumor microenvironment

Background

Within the realm of primary brain tumors, specifically glioblastoma (GBM), presents a notable obstacle due to their unfavorable prognosis and differing median survival rates contingent upon tumor grade and subtype. Despite a plethora of research connecting cardiotrophin-1 (CTF1) modifications to a range of illnesses, its correlation with glioma remains uncertain. This study investigated the clinical value of CTF1 in glioma and its potential as a biomarker of the disease.

Methods

Glioma project in The Cancer Genome Atlas (TCGA) database served as the training cohort, and CGGA 325 series in the Chinese Glioma Genome Atlas (CGGA) database served as the external independent validation cohort. First, the difference in the expression level of CTF1 between glioma tissue and normal tissue was analyzed, and the results were verified with the CGGA database. The relationship between CTF1 expression and the prognosis of glioma patients was evaluated using Univariate and Multivariate Cox analysis and the Kaplan-Meier (KM) curve. We used CIBERSOFT to explore the association between CTF1 and immune cell infiltration in GBM, as well as performing gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) analyses. Furthermore, we analyzed the relationship between CTF1 and gene mutations and drug sensitivity. Using Weighted gene co-expression network analysis (WGCNA) analysis, we pinpointed the gene set most correlated with CTF1 and conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) gene enrichment analyses to anticipate the pathways that could be influenced by CTF1. Finally, we constructed a nomogram using a multifactorial regression model to further predict patient prognosis.

Results

CTF1 expression was significantly elevated in glioma tissues compared to normal tissues in the TCGA dataset (P<0.001) and was associated with poorer survival in both TCGA and CGGA datasets (P<0.001). Receiver operating characteristic (ROC) analysis demonstrated the diagnostic potential of CTF1, with an area under the curve (AUC) of 0.889 [95% confidence interval (CI): 0.803-0.974] in TCGA and 0.664 (95% CI: 0.599-0.729) in CGGA. High CTF1 levels were correlated with advanced glioma grades, and Cox regression analysis identified CTF1 as an independent risk factor. A nomogram incorporating CTF1 levels, isocitrate dehydrogenase 1 (IDH1) mutation status, O6-methylguanine-DNA methyltransferase (MGMT) methylation status, age, and gender were developed and validated to predict 1- and 2-year survival probabilities. In GBM, drug sensitivity analysis revealed significant associations between CTF1 expression and responsiveness to gemcitabine, dasatinib, and other agents. CTF1 expression was also linked to immune infiltration (monocytes, neutrophils, M0 macrophages) and pathways involved in tumor progression, including IL2_STAT5, P53, and IL6_JAK_STAT3 signaling pathways.

Conclusions

CTF1 could serve as a prognostic marker for glioma. It acts as a predictive indicator and is associated with immune cell infiltration in GBM. These findings provide a foundation for further research into the molecular function of CTF1 and offer new insights for exploring the underlying mechanisms and developing treatments for glioma.

Mechanism of non-thermal atmospheric plasma in anti-tumor: influencing intracellular RONS and regulating signaling pathways

Non-thermal atmospheric plasma (NTAP) has been proven to be an effective anti-tumor tool, with various biological effects such as inhibiting tumor proliferation, metastasis, and promoting tumor cell apoptosis. At present, the main conclusion is that ROS and RNS are the main effector components of NTAP, but the mechanisms of which still lack systematic summary. Therefore, in this review, we first summarized the mechanism by which NTAP directly or indirectly causes an increase in intracellular RONS concentration, and the multiple pathways dysregulation (i.e. NRF2, PI3K, MAPK, NF-κB) induced by intracellular RONS. Then, we generalized the relationship between NTAP induced pathways dysregulation and the various biological effects it brought. The summary of the anti-tumor mechanism of NTAP is helpful for its further research and clinical transformation.

Comparative assessment of direct and indirect cold atmospheric plasma effects, based on helium and argon, on human glioblastoma: an in vitro and in vivo study

Recent research has highlighted the promising potential of cold atmospheric plasma (CAP) in cancer therapy. However, variations in study outcomes are attributed to differences in CAP devices and plasma parameters, which lead to diverse compositions of plasma products, including electrons, charged particles, reactive species, UV light, and heat. This study aimed to evaluate and compare the optimal exposure time, duration, and direction-dependent cellular effects of two CAPs, based on argon and helium gases, on glioblastoma U-87 MG cancer cells and an animal model of GBM. Two plasma jets were used as low-temperature plasma sources in which helium or argon gas was ionized by high voltage (4.5 kV) and frequency (20 kHz). In vitro assessments on human GBM and normal astrocyte cell lines, using MTT assays, flow cytometry analysis, wound healing assays, and immunocytochemistry for Caspase3 and P53 proteins, demonstrated that all studied plasma jets, especially indirect argon CAP, selectively induced apoptosis, hindered tumor cell growth, and inhibited migration. These effects occurred concurrently with increased intracellular levels of reactive oxygen species and decreased total antioxidant capacity in the cells. In vivo results further supported these findings, indicating that single indirect argon and direct helium CAP therapy, equal to high dose Temozolomide treatment, induced tumor cell death in a rat model of GBM. This was concurrent with a reduction in tumor size observed through PET-CT scan imaging and a significant increase in the survival rate. Additionally, there was a decrease in GFAP protein levels, a significant GBM tumor marker, and an increase in P53 protein expression based on immunohistochemical analyses. Furthermore, Ledge beam test analysis revealed general motor function improvement after indirect argon CAP therapy, similar to Temozolomide treatment. Taken together, these results suggest that CAP therapy, using indirect argon and direct helium jets, holds great promise for clinical applications in GBM treatment.

Cold atmospheric plasma (CAP) treatment increased reactive oxygen and nitrogen species (RONS) levels in tumor samples obtained from patients with low-grade glioma

Low-grade gliomas (LGGs) are a heterogeneous group of tumors with an average 10-year survival rate of 40%-55%. Current treatment options include chemotherapy, radiotherapy, and gross total resection (GTR) of the tumor. The extent of resection (EOR) plays an important role in improving surgical outcomes. However, the major obstacle in treating low-grade gliomas is their diffused nature and the presence of residual cancer cells at the tumor margins post resection. Cold Atmospheric Plasma (CAP) has shown to be effective in targeted killing of tumor cells in various glioma cell lines without affecting non-tumor cells through Reactive Oxygen and Nitrogen Species (RONS). However, no study on the effectiveness of CAP has been carried out in LGG tissues till date. In this study, we applied helium-based CAP on tumor tissues resected from LGG patients. Our results show that CAP is effective in promoting RONS accumulation in LGG tissues when CAP jet parameters are set at 4 kV voltage, 5 min treatment time and 3 lpm gas flow rate. We also observed that CAP jet is more effective in thinner slice preparations of tumor as compared to thick tumor samples. Our results indicate that CAP could prove to be an effective adjunct therapy in glioma surgery to target residual cancer cells to improve surgical outcome of patients with low-grade glioma.

Identification of circulating miRNA as early diagnostic molecular markers in malignant glioblastoma base on decision tree joint scoring algorithm

PURPOSE

The lack of clinical markers prevents early diagnosis of glioblastoma (GBM). Many studies have found that circulating microRNAs (miRNAs) can be used as early diagnostic markers of malignant tumours. Therefore, the identification of novel circulating miRNA biomolecular markers could be beneficial to clinicians in the early diagnosis of GBM.

METHODS

We developed a decision tree joint scoring algorithm (DTSA), systematically integrating significance analysis of microarray (SAM), Pearson hierarchical clustering, T test, Decision tree and Entropy weight score algorithm, to screen out circulating miRNA molecular markers with high sensitivity and accuracy for early diagnosis of GBM.

RESULTS

DTSA was developed and applied for GBM datasets and three circulating miRNA molecular markers were identified, namely, hsa-miR-2278, hsa-miR-555 and hsa-miR-892b. We have found that hsa-miR-2278 and hsa-miR-892b regulate the GBM pathway through target genes, promoting the development of GBM and affecting the survival of patients. DTSA has better classification effect in all data sets than other classification algorithms, and identified miRNAs are better than existing markers of GBM.

CONCLUSION

These results suggest that DTSA can effectively identify circulating miRNA, thus contributing to the early diagnosis and personalised treatment of GBM.

Medical gas plasma technology: Roadmap on cancer treatment and immunotherapy

Despite continuous therapeutic progress, cancer remains an often fatal disease. In the early 2010s, first evidence in rodent models suggested promising antitumor action of gas plasma technology. Medical gas plasma is a partially ionized gas depositing multiple physico-chemical effectors onto tissues, especially reactive oxygen and nitrogen species (ROS/RNS). Today, an evergrowing body of experimental evidence suggests multifaceted roles of medical gas plasma-derived therapeutic ROS/RNS in targeting cancer alone or in combination with oncological treatment schemes such as ionizing radiation, chemotherapy, and immunotherapy. Intriguingly, gas plasma technology was recently unraveled to have an immunological dimension by inducing immunogenic cell death, which could ultimately promote existing cancer immunotherapies via in situ or autologous tumor vaccine schemes. Together with first clinical evidence reporting beneficial effects in cancer patients following gas plasma therapy, it is time to summarize the main concepts along with the chances and limitations of medical gas plasma onco-therapy from a biological, immunological, clinical, and technological point of view.

Modulation of the Tumor-Associated Immuno-Environment by Non-Invasive Physical Plasma

Over the past 15 years, investigating the efficacy of non-invasive physical plasma (NIPP) in cancer treatment as a safe oxidative stress inducer has become an active area of research. So far, most studies focused on the NIPP-induced apoptotic death of tumor cells. However, whether NIPP plays a role in the anti-tumor immune responses need to be deciphered in detail. In this review, we summarized the current knowledge of the potential effects of NIPP on immune cells, tumor-immune interactions, and the immunosuppressive tumor microenvironment. In general, relying on their inherent anti-oxidative defense systems, immune cells show a more resistant character than cancer cells in the NIPP-induced apoptosis, which is an important reason why NIPP is considered promising in cancer management. Moreover, NIPP treatment induces immunogenic cell death of cancer cells, leading to maturation of dendritic cells and activation of cytotoxic CD8⁺ T cells to further eliminate the cancer cells. Some studies also suggest that NIPP treatment may promote anti-tumor immune responses via other mechanisms such as inhibiting tumor angiogenesis and the desmoplasia of tumor stroma. Though more evidence is required, we expect a bright future for applying NIPP in clinical cancer management.