DSE inhibits melanoma progression by regulating tumor immune cell infiltration and VCAN

Spatial immune heterogeneity in a mouse tumor model after immunotherapy

Cancer immunotherapy is increasingly used in clinical practice, but its success rate is reduced by tumor escape from the immune system. This may be due to the genetic instability of tumor cells, which allows them to adapt to the immune response and leads to intratumoral immune heterogeneity. The study investigated spatial immune heterogeneity in the tumor microenvironment and its possible drivers in a mouse model of tumors induced by human papillomaviruses (HPV) following immunotherapy. Gene expression was determined by RNA sequencing and mutations by whole exome sequencing. A comparison of different tumor areas revealed heterogeneity in immune cell infiltration, gene expression, and mutation composition. While the mean numbers of mutations with every impact on gene expression or protein function were comparable in treated and control tumors, mutations with high or moderate impact were increased after immunotherapy. The genes mutated in treated tumors were significantly enriched in genes associated with ECM metabolism, degradation, and interactions, HPV infection and carcinogenesis, and immune processes such as antigen processing and presentation, Toll-like receptor signaling, and cytokine production. Gene expression analysis of DNA damage and repair factors revealed that immunotherapy upregulated Apobec1 and Apobec3 genes and downregulated genes related to homologous recombination and translesion synthesis. In conclusion, this study describes the intratumoral immune heterogeneity, that could lead to tumor immune escape, and suggests the potential mechanisms involved.

Comprehensive integration of single-cell RNA and transcriptome RNA sequencing to establish a pyroptosis-related signature for improving prognostic prediction of gastric cancer

Cell pyroptosis, a Gasdermin-dependent programmed cell death characterized by inflammasome, plays a complex and dynamic role in Gastric cancer (GC), a serious threat to human health. Therefore, the value of pyroptosis-related genes (PRGs) as prognostic biomarkers and therapeutic indicators for patients needs to be exploited in GC. This study integrates single-cell RNA sequencing (scRNA-seq) dataset GSE183904 with GC transcriptome data from the TCGA database, focusing on the expression and distribution of PRGs in GC at the single-cell level. The prognostic signature of PRGs was established by using Cox and LASSO analyses. The differences in long-term prognosis, immune infiltration, mutation profile, CD274 and response to chemotherapeutic drugs between the two groups were analyzed and evaluated. A tissue array was used to verify the expression of six PRGs, CD274, CD163 and FoxP3. C12orf75, VCAN, RGS2, MKNK2, SOCS3 and TNFAIP2 were successfully screened out to establish a signature to potently predict the survival time of GC patients. A webserver (https://pumc.shinyapps.io/GastricCancer/) for prognostic prediction in GC patients was developed based on this signature. High-risk score patients typically had worse prognoses, resistance to classical chemotherapy, and a more immunosuppressive tumor microenvironment. VCAN, TNFAIP2 and SOCS3 were greatly elevated in the GC while RGS2 and MKNK2 were decreased in the tumor samples. Further, VCAN was positively related to the infiltrations of Tregs and M2 TAMs in GC TME and the CD274 in tumor cells. In summary, a potent pyroptosis-related signature was established to accurately forecast the survival time and treatment responsiveness of GC patients.