The cytokine Meteorin-like inhibits anti-tumor CD8+ T cell responses by disrupting mitochondrial function.

Tumor-infiltrating lymphocyte (TIL) hypofunction contributes to the progression of advanced cancers and is a frequent target of immunotherapy. Emerging evidence indicates that metabolic insufficiency drives T cell hypofunction during tonic stimulation, but the signals that initiate metabolic reprogramming in this context are largely unknown. Here, we found that Meteorin-like (METRNL), a metabolically active cytokine secreted by immune cells in the tumor microenvironment (TME), induced bioenergetic failure of CD8+ T cells. METRNL was secreted by CD8+ T cells during repeated stimulation and acted via both autocrine and paracrine signaling. Mechanistically, METRNL increased E2F-peroxisome proliferator-activated receptor delta (PPARδ) activity, causing mitochondrial depolarization and decreased oxidative phosphorylation, which triggered a compensatory bioenergetic shift to glycolysis. Metrnl ablation or downregulation improved the metabolic fitness of CD8+ T cells and enhanced tumor control in several tumor models, demonstrating the translational potential of targeting the METRNL-E2F-PPARδ pathway to support bioenergetic fitness of CD8+ TILs.

Cross-cultural serious neurological illness communication: qualitative analysis of multidisciplinary perspectives.

BACKGROUND: Cultural competence is important in approaching serious illness communication with diverse patients about goals of care. Culture colors patients' perspectives on many healthcare issues, including end-of-life care, and impacts how clinicians make decisions with patients. Communication about serious neurological illnesses can be additionally challenging due to disease impact on patients' cognition and decision-making abilities. We aim to understand provider experiences regarding cross-cultural serious neurological illness communication with diverse patients and families. METHODS: Using non-stratified purposive and snowball sampling, we conducted semi-structured interviews with 17 multidisciplinary participants, including neurosurgeons, neurologists, and social workers, who provide care for patients diagnosed with serious neurological disorders, at three hospital settings between 2021 and 2022. We used standard qualitative content analysis methods with dual review. RESULTS: Five themes reflected provider perspectives about serious neurological illness communication with diverse patients and families. Theme 1: providers recognize that patients' personal biases and lived experiences impact attitudes about healthcare and communication. Theme 2: challenges in communication can arise when providers miss chances to identify important cultural values. Theme 3: understanding how to engage with family members is important for effective communication about serious neurological illness. Theme 4: providers want to accommodate patients. Theme 5: cultivating trust builds a strong patientprovider partnership, even when racial or cultural discordance is present. CONCLUSIONS: Our study highlights elements of cross-cultural communication and opportunities for providers to approach diverse patients and families within a racial or culturally discordant context. Effective communication, fostered through respecting individual experiences and variation, eliciting cultural perspectives, engaging family, and cultivating trust reflects processes and learned skills required of highquality teams caring for patients with serious neurological conditions.

The CCR6-CCL20 axis promotes regulatory T cell glycolysis and immunosuppression in tumors.

Regulatory T cells (Tregs) are important players in the tumor microenvironment. However, the mechanisms behind their immunosuppressive effects are poorly understood. We found that CCR6-CCL20 activity in tumor-infiltrating Tregs is associated with greater glycolytic activity and ablation of Ccr6 reduced glycolysis and lactic acid production while increasing compensatory glutamine metabolism. Immunosuppressive activity towards CD8+ T cells was abrogated in Ccr6-/- Tregs due to reduction in activation-induced glycolysis. Furthermore, Ccr6-/- mice exhibited improved survival across multiple tumor models compared to wildtype mice, and Treg and CD8+ T-cell depletion abrogated the improvement. In addition, Ccr6 ablation further promoted the efficacy of anti-PD-1 therapy in a preclinical glioma model. Follow-up knockdown of Ccl20 with siRNA also demonstrated improvement in antitumor efficacy. Our results unveil CCR6 as a marker and regulator of Treg-induced immunosuppression and identify approaches to target the metabolic determinants of Treg immunosuppressive activity.

CyberKnife stereotactic radiosurgery for extramedullary plasmacytoma in the external auditory canal: illustrative case.

BACKGROUND: Plasmacytoma, a rare plasma cell disorder, often presents as a solitary or multiple tumors within the bone marrow or soft tissues, typically associated with multiple myeloma. Extramedullary plasmacytomas (EMPs), particularly those located in the external auditory canal (EAC), are exceedingly rare and pose significant treatment challenges given their location, anatomical complexity, and high risk of recurrence. OBSERVATIONS: The authors report the case of a 72-year-old male with a history of multiple myeloma, presenting with recurrent left EAC plasmacytoma. After initial conventional radiotherapy for the lesion, a recurrence was documented in 7 years. The patient subsequently underwent stereotactic radiosurgery, which proved successful, leading to complete resolution of the lesion without any long-term adverse effects or radiation-related complications over a 45-month period. LESSONS: This case is a unique instance of utilizing stereotactic radiosurgery for recurrent EMP in the EAC, highlighting its potential as an effective approach in managing complex plasmacytomas.

SMARCA4 deficiency and mutations are frequent in large cell lung carcinoma and are prognostically significant.

SMARCA4 mutation has emerged as a marker of poor prognosis in lung cancer and has potential predictive value in cancer treatment, but recommendations for which patients require its investigation are lacking. We comprehensively studied SMARCA4 alterations and the clinicopathological significance in a large cohort of immunohistochemically-subtyped non-small cell lung cancer (NSCLC). A total of 1416 patients was studied for the presence of SMARCA4 deficiency by immunohistochemistry (IHC). Thereafter, comprehensive sequencing of tumours was performed for 397 of these patients to study the mutational spectrum of SWI/SNF and SMARCA4 aberrations. IHC evidence of SMARCA4 deficiency was found in 2.9% of NSCLC. Of the sequenced tumours, 38.3% showed aberration in SWI/SNF complex, and 9.3% had SMARCA4 mutations. Strikingly, SMARCA4 aberrations were much more prevalent in large cell carcinoma (LCC) than other histological tumour subtypes. SMARCA4-deficient and SMARCA4-mutated tumours accounted for 40.5% and 51.4% of all LCC, respectively. Multivariable analyses confirmed SMARCA4 mutation was an independent prognostic factor in lung cancer. The immunophenotype of a subset of these tumours frequently showed TTF1 negativity and HepPAR1 positivity. SMARCA4 mutation or its deficiency was associated with positive smoking history and poor prognosis. It also demonstrated mutual exclusion with EGFR mutation. Taken together, the high incidence of SMARCA4 aberrations in LCC may indicate its diagnostic and prognostic value. Our study established the necessity of SMARCA4 IHC in the identification of SMARCA4-aberrant tumours, and this may be of particular importance in LCC and tumours without known driver events.