Probes for TNF

Detection of individual cytokines in routine biopsies from patients with inflammatory skin diseases has the potential to personalize diagnosis and treatment selection, but this approach has been limited by technical feasibility. We evaluate whether a chromogen-based RNA in situ hybridization approach can be used to detect druggable cytokines in psoriasis and atopic dermatitis. A series of psoriasis (n = 20) and atopic dermatitis (n = 26) biopsies were stained using RNA in situ hybridization for IL4, IL12B (IL-12/23 p40), IL13, IL17A, IL17F, IL22, IL23A (IL-23 p19), IL31, and TNF (TNF-α). NOS2 and IFNG, canonical psoriasis biomarkers, were also included. All 20 of the psoriasis cases were positive for IL17A, which tended to be the predominant cytokine, although some cases had relatively higher levels of IL12B, IL17F, or IL23A. The majority of cytokine expression in psoriasis was epidermal. A total of 22 of 26 atopic dermatitis cases were positive for IL13, also at varying levels; a subset of cases had significant IL4, IL22, or IL31 expression. Patterns were validated in independent bulk RNA-sequencing and single-cell RNA-sequencing datasets. Overall, RNA in situ hybridization for cytokines appears highly specific with virtually no background staining and may allow for individualized evaluation of treatment-relevant cytokine targets in biopsies from patients with inflammatory skin disorders.

Tumor-elicited inflammation confers tumorigenic properties, including cell death resistance, proliferation, or immune evasion. To focus on inflammatory signaling in tumors, we investigated linear ubiquitination, which enhances the nuclear factor-κB signaling pathway and prevents extrinsic programmed cell death under inflammatory environments. Here, we showed that linear ubiquitination was augmented especially in tumor cells around a necrotic core. Linear ubiquitination allowed melanomas to tolerate the hostile tumor microenvironment and to extend a necrosis-containing morphology. Loss of linear ubiquitination resulted in few necrotic lesions and growth regression, further leading to repression of innate anti-PD-1 therapy resistance signatures in melanoma as well as activation of interferon responses and antigen presentation that promote immune-mediated tumor eradication. Collectively, linear ubiquitination promotes tumor-specific tissue remodeling and the ensuing immune evasion.

Immune checkpoint blockade is therapeutically successful for many patients across multiple cancer types. However, immune-related adverse events (irAE) frequently occur and can sometimes be life threatening. It is critical to understand the immunologic mechanisms of irAEs with the goal of finding novel treatment targets. Herein, we report our analysis of tissues from patients with irAE dermatitis using multiparameter immunofluorescence (IF), spatial transcriptomics, and RNA in situ hybridization (RISH). Skin psoriasis cases were studied as a comparison, as a known Th17-driven disease, and colitis was investigated as a comparison. IF analysis revealed that CD4+ and CD8+ tissue-resident memory T (TRM) cells were preferentially expanded in the inflamed portion of skin in cutaneous irAEs compared with healthy skin controls. Spatial transcriptomics allowed us to focus on areas containing TRM cells to discern functional phenotype and revealed expression of Th1-associated genes in irAEs, compared with Th17-asociated genes in psoriasis. Expression of PD-1, CTLA-4, LAG-3, and other inhibitory receptors was observed in irAE cases. RISH technology combined with IF confirmed expression of IFNγ, CXCL9, CXCL10, and TNFα in irAE dermatitis, as well as IFNγ within TRM cells specifically. The Th1-skewed phenotype was confirmed in irAE colitis cases compared with healthy colon.

Chemotherapy resistance is a critical contributor to cancer mortality and thus an urgent unmet challenge in oncology. To characterize chemotherapy resistance processes in high-grade serous ovarian cancer, we prospectively collected tissue samples before and after chemotherapy and analyzed their transcriptomic profiles at a single-cell resolution. After removing patient-specific signals by a novel analysis approach, PRIMUS, we found a consistent increase in stress-associated cell state during chemotherapy, which was validated by RNA in situ hybridization and bulk RNA sequencing. The stress-associated state exists before chemotherapy, is subclonally enriched during the treatment, and associates with poor progression-free survival. Co-occurrence with an inflammatory cancer-associated fibroblast subtype in tumors implies that chemotherapy is associated with stress response in both cancer cells and stroma, driving a paracrine feed-forward loop. In summary, we have found a resistant state that integrates stromal signaling and subclonal evolution and offers targets to overcome chemotherapy resistance.