FOXA1 repression drives lineage plasticity and immune heterogeneity in bladder cancers with squamous differentiation.

Cancers arising from the bladder urothelium often exhibit lineage plasticity with regions of urothelial carcinoma adjacent to or admixed with regions of divergent histomorphology, most commonly squamous differentiation. To define the biologic basis for and clinical significance of this morphologic heterogeneity, here we perform integrated genomic analyses of mixed histology bladder cancers with separable regions of urothelial and squamous differentiation. We find that squamous differentiation is a marker of intratumoral genomic and immunologic heterogeneity in patients with bladder cancer and a biomarker of intrinsic immunotherapy resistance. Phylogenetic analysis confirms that in all cases the urothelial and squamous regions are derived from a common shared precursor. Despite the presence of marked genomic heterogeneity between co-existent urothelial and squamous differentiated regions, no recurrent genomic alteration exclusive to the urothelial or squamous morphologies is identified. Rather, lineage plasticity in bladder cancers with squamous differentiation is associated with loss of expression of FOXA1, GATA3, and PPARG, transcription factors critical for maintenance of urothelial cell identity. Of clinical significance, lineage plasticity and PD-L1 expression is coordinately dysregulated via FOXA1, with patients exhibiting morphologic heterogeneity pre-treatment significantly less likely to respond to immune checkpoint inhibitors.

Genomic Alterations as Potential Therapeutic Targets in Extramammary Paget's Disease of the Vulva.

PURPOSE: To identify genomic alterations as potential therapeutic targets in extramammary Paget disease (EMPD) of the vulva. METHODS: We identified all patients with primary vulvar EMPD who were treated at our institution and underwent paired tumor-normal massively parallel sequencing of 410-468 cancer-related genes (MSK-IMPACT assay). EMPD of the vulva samples sequenced from 2014 to 2019 were reviewed and somatic mutations identified, with specific focus on mutations of potential therapeutic targets. Clinical data were abstracted from electronic medical records. Microsatellite instability (MSI) was assessed by MSIscore. RESULTS: Tumors of 26 patients with EMPD underwent genomic sequencing. At diagnosis, all patients had noninvasive or microinvasive (< 1 mm) disease; invasive disease eventually developed in 2 patients. Primary treatment was surgery for 19 patients (73%) and imiquimod topical therapy for 7 (27%). Seven patients had ≥ 2 surgeries as part of clinical course (1 patient had 5 vulvar resections). Samples had a median of 2 coding mutations in the genes analyzed (range, 0-29). The most common mutations were in PIK3CA (n = 9; 35%), ERBB2 (4 mutations and 3 copy number alterations; 27%), and TP53 (n = 7; 27%). MSIscore was available for 23 samples; all were microsatellite stable. After tumor genomic profiling, a patient who was initially treated with multiple resections and imiquimod was found to have a PIK3CA p.E542K mutation. She underwent PI3K-inhibitor treatment for 18 months before disease progression. CONCLUSION: EMPD of the vulva has a chronic and relapsing course, often requiring multiple surgical resections. Effective topical treatments are lacking. We identified targetable mutations (PIK3CA or ERBB2) in > 25% of a real-world clinical cohort. Additional prospective research implementing targetable therapies for EMPD treatment is warranted.

Cancer biology as revealed by the research autopsy.

A research autopsy is a post-mortem medical procedure performed on a deceased individual with the primary goal of collecting tissue to support basic and translational research. This approach has increasingly been used to investigate the pathophysiological mechanisms of cancer evolution, metastasis and treatment resistance. In this Review, we discuss the rationale for the use of research autopsies in cancer research and provide an evidence-based discussion of the quality of post-mortem tissues compared with other types of biospecimens. We also discuss the advantages of using post-mortem tissues over other types of biospecimens, including the large amounts of tissue that can be obtained and the extent of multiregion sampling that is achievable, which is not otherwise possible in living patients. We highlight how the research autopsy has supported the identification of the clonal origins and modes of spread among metastases, the extent that selective pressures imposed by treatments cause bottlenecks leading to parallel and convergent tumour evolution, and the creation of rare tissue banks and patient-derived model systems. Finally, we comment on the future of the research autopsy as an integral component of precision medicine strategies.

Absence of the complement anaphylatoxin C3a receptor suppresses Th2 effector functions in a murine model of pulmonary allergy.

Asthma is a chronic inflammatory disease of the lung resulting in airway obstruction. The airway inflammation of asthma is strongly linked to Th2 lymphocytes and their cytokines, particularly IL-4, IL-5, and IL-13, which regulate airway hyperresponsiveness, eosinophil activation, mucus production, and IgE secretion. Historically, complement was not thought to contribute to the pathogenesis of asthma. However, our previous reports have demonstrated that complement contributes to bronchial hyperreactivity, recruitment of airway eosinophils, IL-4 production, and IgE responses in a mouse model of pulmonary allergy. To define the complement activation fragments that mediate these effects, we assessed the role of the complement anaphylatoxin C3a in a mouse model of pulmonary allergy by challenging C3aR-deficient mice intranasally with a mixed Ag preparation of Aspergillus fumigatus cell culture filtrate and OVA. Analysis by plethysmography after challenge revealed an attenuation in airway hyperresponsiveness in C3aR-deficient mice relative to wild-type mice. C3aR-deficient mice also had an 88% decrease in airway eosinophils and a 59% reduction in lung IL-4-producing cells. Consistent with the reduced numbers of IL-4-producing cells, C3aR-deficient mice had diminished bronchoalveolar lavage levels of the Th2 cytokines, IL-5 and IL-13. C3aR knockout mice also exhibited decreases in IgE titers as well as reduced mucus production. Collectively, these data highlight the importance of complement activation, the C3a anaphylatoxin, and its receptor during Th2 development in this experimental model and implicate these molecules as possible therapeutic targets in diseases such as asthma.