CD95 (Fas) and CD95L (FasL)-mediated non-canonical signaling pathways

Novel engineered IL-2 Nemvaleukin alfa combined with PD1 checkpoint blockade enhances the systemic anti-tumor responses of radiation therapy

BACKGROUND

Combining interleukin-2 (IL-2) with radiotherapy (RT) and immune checkpoint blockade (ICB) has emerged as a promising approach to address ICB resistance. However, conventional IL-2 cytokine therapy faces constraints owing to its brief half-life and adverse effects. RDB 1462, the mouse ortholog of Nemvaleukin alfa, is an engineered IL-2 with an intermediate affinity that selectively stimulates antitumor CD8 T and NK cells while limiting regulatory T cell expansion. This study aimed to evaluate the antitumor activity and mechanism of action of the combination of RDB 1462, RT, and anti-PD1 in mouse tumor models.

METHODS

Two bilateral lung adenocarcinoma murine models were established using 344SQ-Parental and 344SQ anti-PD1-resistant cell lines. Primary tumors were treated with RT, and secondary tumors were observed for evidence of abscopal effects. We performed immune phenotyping by flow cytometry, analyzed 770 immune-related genes using NanoString, and performed T cell receptor (TCR) repertoire analysis. Serum pro-inflammatory cytokine markers were analyzed by 23-plex kit.

RESULTS

Compared to native IL-2 (RDB 1475), RDB 1462 demonstrated superior systemic antitumoral responses, attributable, at least in part, to augmented levels of CD4 and CD8 T cells with the latter. Our findings reveal substantial reductions in primary and secondary tumor volumes compared to monotherapy controls, with some variability observed among different dosing schedules of RDB 1462 combined with RT. Blood and tumor tissue-based flow cytometric phenotyping reveals an increase in effector memory CD8 and CD4 T cells and a decrease in immunosuppressive cells accompanied by a significant increase in IL-2, IFN-γ, and GM-CSF levels in the combination group. Transcriptomic profiling and TCR sequencing reveal favorable gene expression and T cell repertoire patterns with the dual combination. Furthermore, integrating anti-PD1 therapy with RT and RDB 1462 further reduced primary and secondary tumor volumes, prolonged survival, and decreased lung metastasis. Observations of immune cell profiles indicated that RT with escalating doses of RDB 1462 significantly reduced tumor growth and increased tumor-specific immune cell populations.

CONCLUSION

The addition of Nemvaleukin therapy may enhance responses to RT alone and in combination with anti-PD1.

Focused ultrasound-induced cell apoptosis for the treatment of tumours

Cancer is a serious public health problem worldwide. Traditional treatments, such as surgery, radiotherapy, chemotherapy, and immunotherapy, do not always yield satisfactory results; therefore, an efficient treatment for tumours is urgently needed. As a convenient and minimally invasive modality, focused ultrasound (FUS) has been used not only as a diagnostic tool but also as a therapeutic tool in an increasing number of studies. FUS can help treat malignant tumours by inducing apoptosis. This review describes the three apoptotic pathways, apoptotic cell clearance, and how FUS affects these three apoptotic pathways. This review also discusses the role of thermal and cavitation effects on apoptosis, including caspase activity, mitochondrial dysfunction, and Ca2+ elease. Finally, this article reviews various aspects of FUS combination therapy, including sensitization by radiotherapy and chemotherapy, gene expression upregulation, and the introduction of therapeutic gases, to provide new ideas for clinical tumour therapy.

Glycosylation: mechanisms, biological functions and clinical implications

Protein post-translational modification (PTM) is a covalent process that occurs in proteins during or after translation through the addition or removal of one or more functional groups, and has a profound effect on protein function. Glycosylation is one of the most common PTMs, in which polysaccharides are transferred to specific amino acid residues in proteins by glycosyltransferases. A growing body of evidence suggests that glycosylation is essential for the unfolding of various functional activities in organisms, such as playing a key role in the regulation of protein function, cell adhesion and immune escape. Aberrant glycosylation is also closely associated with the development of various diseases. Abnormal glycosylation patterns are closely linked to the emergence of various health conditions, including cancer, inflammation, autoimmune disorders, and several other diseases. However, the underlying composition and structure of the glycosylated residues have not been determined. It is imperative to fully understand the internal structure and differential expression of glycosylation, and to incorporate advanced detection technologies to keep the knowledge advancing. Investigations on the clinical applications of glycosylation focused on sensitive and promising biomarkers, development of more effective small molecule targeted drugs and emerging vaccines. These studies provide a new area for novel therapeutic strategies based on glycosylation.

The PRC2 complex epigenetically silences GATA4 to suppress cellular senescence and promote the progression of breast cancer

BACKGROUND

The transcription factor GATA4 is pivotal in cancer development but is often silenced through mechanisms like DNA methylation and histone modifications. This silencing suppresses the transcriptional activity of GATA4, disrupting its normal functions and promoting cancer progression. However, the precise molecular mechanisms and implications of GATA4 silencing in tumorigenesis remain unclear. Here, we aim to elucidate the mechanisms underlying GATA4 silencing and explore its role in breast cancer progression and its potential as a therapeutic target.

METHODS

The GATA4-breast cancer prognosis link was explored via bioinformatics analyses, with GATA4 expression measured in breast tissues. Functional gain/loss experiments were performed to gauge GATA4's impact on breast cancer cell malignancy. GATA4-PRC2 complex interaction was analyzed using silver staining and mass spectrometry. Chromatin immunoprecipitation, coupled with high-throughput sequencing, was used to identify GATA4-regulated downstream target genes. The in vitro findings were validated in an in situ breast cancer xenograft mouse model.

RESULTS

GATA4 mutation and different breast cancer subtypes were correlated, suggesting its involvement in disease progression. GATA4 suppressed cell proliferation, invasion, and migration while inducing apoptosis and senescence in breast cancer cells. The GATA4-PRC2 complex interaction silenced GATA4 expression, which altered the regulation of FAS, a GATA4 downstream gene. In vivo experiments verified that GATA4 inhibits tumor growth, suggesting its regulatory function in tumorigenesis.

CONCLUSIONS

This comprehensive study highlights the epigenetic regulation of GATA4 and its impact on breast cancer development, highlighting the PRC2-GATA4-FAS pathway as a potential target for therapeutic interventions in breast cancers.

Natural isothiocyanates of the genus Capparis as potential agonists of apoptosis and antitumor agents: Mechanisms and implications

In this editorial, we comment on a recent publication, which highlights the important findings from the study, including the antitumor and anti-inflammatory effects of isothiocyanates, their underlying mechanisms, and implications. Additionally, a related perspective is discussed.

Polymorphism of apoptosis marker genes in the blood of indigenous people with gastric cancer in the Republic of Tyva

Introduction. Russia is among the leaders in incidence and mortality from gastric cancer (GC). The incidence of gastric cancer in the Republic of Tyva is especially abnormally high. Currently, there is interest in studying genetic factors in various types of cancer. But for GC, such research is not enough.

Aim. To study the polymorphism of the apoptosis marker genes CASP9 (rs1052576), TP53 (rs1042522), FAS/APO-1 (rs2234767) in the blood of indigenous people with GC in the Republic of Tyva.

Materials and methods. 107 Tuvinians were examined (47 people with GC and 60 persons in the control group). The diagnosis of GC was established on the basis of a comprehensive laboratory, instrumental and morphological examination by oncologists at the Republican Oncology Dispensary. Genotyping of polymorphisms rs1052576 CASP9, rs2234767 FAS/APO-1 and rs1042522 TP53 was carried out in all 47 patients with GC and in 60 people in the control group using the polymerase chain reaction method from DNA samples isolated from venous blood.

Results. In patients with GC, compared with healthy individuals, the mutant allele G (44.7% versus 27.5%; p = 0.01) and the homozygous genotype GG (23.4% versus 6.7%; p = 0.03) of polymorphism rs1042522 TP53, as well as mutant allele A (57.4% versus 32.5%; p < 0.001) and homozygous genotype AA (31.9% versus 15.0%; p = 0.05) of polymorphism rs2234767 FAS/ APO-1 were more often registered among indigenous inhabitants of the Republic of Tyva. The frequency of various genotypes and alleles of the polymorphism rs1052576 CASP9 did not differ significantly between patients with GC and healthy individuals.

Conclusion. Based on these results, it can be assumed that the A allele of rs2234767 FAS/APO-1 and the disruption of the anti-oncogenic function of the p53 protein produced by the G allele of rs1042522 TP53 are associated with GC and can be used as markers to determine increased risk in the population of indigenous residents of the Republic of Tyva.

Changes Induced by P2X7 Receptor Stimulation of Human Glioblastoma Stem Cells in the Proteome of Extracellular Vesicles Isolated from Their Secretome

Extracellular vesicles (EVs) are secreted from many tumors, including glioblastoma multiforme (GBM), the most common and lethal brain tumor in adults, which shows high resistance to current therapies and poor patient prognosis. Given the high relevance of the information provided by cancer cell secretome, we performed a proteomic analysis of microvesicles (MVs) and exosomes (EXOs) released from GBM-derived stem cells (GSCs). The latter, obtained from the brain of GBM patients, expressed P2X7 receptors (P2X7Rs), which positively correlate with GBM growth and invasiveness. P2X7R stimulation of GSCs caused significant changes in the EV content, mostly ex novo inducing or upregulating the expression of proteins related to cytoskeleton reorganization, cell motility/spreading, energy supply, protection against oxidative stress, chromatin remodeling, and transcriptional regulation. Most of the induced/upregulated proteins have already been identified as GBM diagnostic/prognostic factors, while others have only been reported in peripheral tumors. Our findings indicate that P2X7R stimulation enhances the transport and, therefore, possible intercellular exchange of GBM aggressiveness-increasing proteins by GSC-derived EVs. Thus, P2X7Rs could be considered a new druggable target of human GBM, although these data need to be confirmed in larger experimental sets.

Mesenchymal stromal cell derived extracellular vesicles as a therapeutic tool: immune regulation, MSC priming, and applications to SLE

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a dysfunction of the immune system. Mesenchymal stromal cell (MSCs) derived extracellular vesicles (EVs) are nanometer-sized particles carrying a diverse range of bioactive molecules, such as proteins, miRNAs, and lipids. Despite the methodological disparities, recent works on MSC-EVs have highlighted their broad immunosuppressive effect, thus driving forwards the potential of MSC-EVs in the treatment of chronic diseases. Nonetheless, their mechanism of action is still unclear, and better understanding is needed for clinical application. Therefore, we describe in this review the diverse range of bioactive molecules mediating their immunomodulatory effect, the techniques and possibilities for enhancing their immune activity, and finally the potential application to SLE.