Cytotoxic innate lymphoid cells sense cancer cell-expressed interleukin-15 to suppress human and murine malignancies.

Malignancy can be suppressed by the immune system. However, the classes of immunosurveillance responses and their mode of tumor sensing remain incompletely understood. Here, we show that although clear cell renal cell carcinoma (ccRCC) was infiltrated by exhaustion-phenotype CD8+ T cells that negatively correlated with patient prognosis, chromophobe RCC (chRCC) had abundant infiltration of granzyme A-expressing intraepithelial type 1 innate lymphoid cells (ILC1s) that positively associated with patient survival. Interleukin-15 (IL-15) promoted ILC1 granzyme A expression and cytotoxicity, and IL-15 expression in chRCC tumor tissue positively tracked with the ILC1 response. An ILC1 gene signature also predicted survival of a subset of breast cancer patients in association with IL-15 expression. Notably, ILC1s directly interacted with cancer cells, and IL-15 produced by cancer cells supported the expansion and anti-tumor function of ILC1s in a murine breast cancer model. Thus, ILC1 sensing of cancer cell IL-15 defines an immunosurveillance mechanism of epithelial malignancies.

Tumor and Microenvironment Evolution during Immunotherapy with Nivolumab.

The mechanisms by which immune checkpoint blockade modulates tumor evolution during therapy are unclear. We assessed genomic changes in tumors from 68 patients with advanced melanoma, who progressed on ipilimumab or were ipilimumab-naive, before and after nivolumab initiation (CA209-038 study). Tumors were analyzed by whole-exome, transcriptome, and/or T cell receptor (TCR) sequencing. In responding patients, mutation and neoantigen load were reduced from baseline, and analysis of intratumoral heterogeneity during therapy demonstrated differential clonal evolution within tumors and putative selection against neoantigenic mutations on-therapy. Transcriptome analyses before and during nivolumab therapy revealed increases in distinct immune cell subsets, activation of specific transcriptional networks, and upregulation of immune checkpoint genes that were more pronounced in patients with response. Temporal changes in intratumoral TCR repertoire revealed expansion of T cell clones in the setting of neoantigen loss. Comprehensive genomic profiling data in this study provide insight into nivolumab's mechanism of action.

Tumor-associated macrophages expressing the transcription factor IRF8 promote T cell exhaustion in cancer.

Tumors are populated by antigen-presenting cells (APCs) including macrophage subsets with distinct origins and functions. Here, we examined how cancer impacts mononuclear phagocytic APCs in a murine model of breast cancer. Tumors induced the expansion of monocyte-derived tumor-associated macrophages (TAMs) and the activation of type 1 dendritic cells (DC1s), both of which expressed and required the transcription factor interferon regulatory factor-8 (IRF8). Although DC1s mediated cytotoxic T lymphocyte (CTL) priming in tumor-draining lymph nodes, TAMs promoted CTL exhaustion in the tumor, and IRF8 was required for TAMs' ability to present cancer cell antigens. TAM-specific IRF8 deletion prevented exhaustion of cancer-cell-reactive CTLs and suppressed tumor growth. Tumors from patients with immune-infiltrated renal cell carcinoma had abundant TAMs that expressed IRF8 and were enriched for an IRF8 gene expression signature. Furthermore, the TAM-IRF8 signature co-segregated with CTL exhaustion signatures across multiple cancer types. Thus, CTL exhaustion is promoted by TAMs via IRF8.

TGF-ß suppresses type 2 immunity to cancer.

The immune system uses two distinct defence strategies against infections: microbe-directed pathogen destruction characterized by type 1 immunity1, and host-directed pathogen containment exemplified by type 2 immunity in induction of tissue repair2. Similar to infectious diseases, cancer progresses with self-propagating cancer cells inflicting host-tissue damage. The immunological mechanisms of cancer cell destruction are well defined3-5, but whether immune-mediated cancer cell containment can be induced remains poorly understood. Here we show that depletion of transforming growth factor-ß receptor 2 (TGFBR2) in CD4+ T cells, but not CD8+ T cells, halts cancer progression as a result of tissue healing and remodelling of the blood vasculature, causing cancer cell hypoxia and death in distant avascular regions. Notably, the host-directed protective response is dependent on the T helper 2 cytokine interleukin-4 (IL-4), but not the T helper 1 cytokine interferon-γ (IFN-γ). Thus, type 2 immunity can be mobilized as an effective tissue-level defence mechanism against cancer.

Genomic ancestry in kidney cancer: Correlations with clinical and molecular features.

INTRODUCTION: Genetic ancestry (GA) refers to population hereditary patterns that contribute to phenotypic differences seen among race/ethnicity groups, and differences among GA groups may highlight unique biological determinants that add to our understanding of health care disparities. METHODS: A retrospective review of patients with renal cell carcinoma (RCC) was performed and correlated GA with clinicopathologic, somatic, and germline molecular data. All patients underwent next-generation sequencing of normal and tumor DNA using Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets, and contribution of African (AFR), East Asian (EAS), European (EUR), Native American, and South Asian (SAS) ancestry was inferred through supervised ADMIXTURE. Molecular data was compared across GA groups by Fisher exact test and Kruskal-Wallis test. RESULTS: In 953 patients with RCC, the GA distribution was: EUR (78%), AFR (4.9%), EAS (2.5%), SAS (2%), Native American (0.2%), and Admixed (12.2%). GA distribution varied by tumor histology and international metastatic RCC database consortium disease risk status (intermediate-poor: EUR 58%, AFR 88%, EAS 74%, and SAS 73%). Pathogenic/likely pathogenic germline variants in cancer-predisposition genes varied (16% EUR, 23% AFR, 8% EAS, and 0% SAS), and most occurred in CHEK2 in EUR (3.1%) and FH in AFR (15.4%). In patients with clear cell RCC, somatic alteration incidence varied with significant enrichment in BAP1 alterations (EUR 17%, AFR 50%, SAS 29%; p = .01). Comparing AFR and EUR groups within The Cancer Genome Atlas, significant differences were identified in angiogenesis and inflammatory pathways. CONCLUSION: Differences in clinical and molecular data by GA highlight population-specific variations in patients with RCC. Exploration of both genetic and nongenetic variables remains critical to optimize efforts to overcome health-related disparities.

Pre-capture multiplexing provides additional power to detect copy number variation in exome sequencing.

BACKGROUND: As exome sequencing (ES) integrates into clinical practice, we should make every effort to utilize all information generated. Copy-number variation can lead to Mendelian disorders, but small copy-number variants (CNVs) often get overlooked or obscured by under-powered data collection. Many groups have developed methodology for detecting CNVs from ES, but existing methods often perform poorly for small CNVs and rely on large numbers of samples not always available to clinical laboratories. Furthermore, methods often rely on Bayesian approaches requiring user-defined priors in the setting of insufficient prior knowledge. This report first demonstrates the benefit of multiplexed exome capture (pooling samples prior to capture), then presents a novel detection algorithm, mcCNV ("multiplexed capture CNV"), built around multiplexed capture. RESULTS: We demonstrate: (1) multiplexed capture reduces inter-sample variance; (2) our mcCNV method, a novel depth-based algorithm for detecting CNVs from multiplexed capture ES data, improves the detection of small CNVs. We contrast our novel approach, agnostic to prior information, with the the commonly-used ExomeDepth. In a simulation study mcCNV demonstrated a favorable false discovery rate (FDR). When compared to calls made from matched genome sequencing, we find the mcCNV algorithm performs comparably to ExomeDepth. CONCLUSION: Implementing multiplexed capture increases power to detect single-exon CNVs. The novel mcCNV algorithm may provide a more favorable FDR than ExomeDepth. The greatest benefits of our approach derive from (1) not requiring a database of reference samples and (2) not requiring prior information about the prevalance or size of variants.

Genetic variation in catechol-O-methyltransferase is associated with individual differences in conditioned pain modulation in healthy subjects.

BACKGROUND: Genetic variation in the catechol-O-methyltransferase (COMT) gene is associated with sensitivity to both acute experimental pain and chronic pain conditions. Four single nucleotide polymorphisms (SNPs) have traditionally been used to infer three common haplotypes designated as low, average and high pain sensitivity and are reported to affect both COMT enzymatic activity and pain sensitivity. One mechanism that may partly explain individual differences in sensitivity to pain is conditioned pain modulation (CPM). We hypothesized that variation in CPM may have a genetic basis. METHODS: We evaluated CPM in 77 healthy pain-free Caucasian subjects by applying repeated mechanical stimuli to the dominant forearm using 26-g von Frey filament as the test stimulus with immersion of the non-dominant hand in hot water as the conditioning stimulus. We assayed COMT SNP genotypes by the TaqMan method using DNA extracted from saliva. RESULTS: SNP rs4680 (val158 met) was not associated with individual differences in CPM. However, CPM was associated with COMT low pain sensitivity haplotypes under an additive model (p = 0.004) and the effect was independent of gender. CONCLUSIONS: We show that, although four SNPs are used to infer COMT haplotypes, the low pain sensitivity haplotype is determined by SNP rs6269 (located in the 5' regulatory region of COMT), suggesting that inherited variation in gene expression may underlie individual differences in pain modulation. Analysis of 13 global populations revealed that the COMT low pain sensitivity haplotype varies in frequency from 13% to 44% and showed that two SNPs are sufficient to distinguish all COMT haplotypes in most populations.

Transcriptomic signatures related to the obesity paradox in patients with clear cell renal cell carcinoma: a cohort study.

BACKGROUND: Obesity is associated with an increased risk of developing clear cell renal cell carcinoma (RCC) but, paradoxically, obesity is also associated with improved oncological outcomes in this cancer. Because the biological mechanisms underlying this paradoxical association are poorly understood, we aimed to identify transcriptomic differences in primary tumour and peritumoral adipose tissue between obese patients and those at a normal weight. METHODS: In this cohort study, we assessed data from five independent clinical cohorts of patients with clear cell RCC aged 18 years and older. Overweight patients were excluded from each cohort for our analysis. We assessed patients from the COMPARZ phase 3 clinical trial, a cohort from the Cancer Genome Atlas (TCGA), and a Memorial Sloan Kettering (MSK) observational immunotherapy cohort for their inclusion into our study. We assessed overall survival in obese patients (those with a body-mass index [BMI] ≥30 kg/m2) and in patients with a normal weight (BMI 18·5-24·9 kg/m2, as per WHO's BMI categories), defined as the time from treatment initiation (in the COMPARZ and MSK immunotherapy cohorts) or surgery (in the TCGA cohort) to the date of any-cause death or of censoring on the day of the last follow-up. We also evaluated and validated transcriptomic differences in the primary tumours of obese patients compared with those of a normal weight. We compared gene-expression differences in peritumoral adipose tissue and tumour tissue in an additional, prospectively collected cohort of patients with non-metastatic clear cell RCC (the MSK peritumoral adipose tissue cohort). We analysed differences in gene expression between obese patients and those at a normal weight in the COMPARZ, TCGA, and peritumoral adipose tissue cohorts. We also assessed the tumour immune microenvironment in a prospective cohort of patients who had nephrectomy for localised RCC at MSK. FINDINGS: Of the 453 patients in the COMPARZ trial, 375 (83%) patients had available microarray data, pretreatment BMI measurements, and overall survival data for analyses, and we excluded 119 (26%) overweight patients, leaving a final cohort of 256 (68%) patients from this study for our analyses. From 332 patients in the TCGA cohort, we evaluated clinical and demographic data from 152 (46%) patients with advanced (ie, stages III and IV) clear cell RCC treated by nephrectomy; after exclusion of 59 (39%) overweight patients, our final cohort consisted of 93 (61%) patients. After exclusion of 74 (36%) overweight patients from the initial MSK immunotherapy study population of 203 participants, our final cohort for overall survival analysis comprised 129 (64%) participants. We found that overall survival was longer in obese patients than in those with normal weight in the TCGA cohort, after adjustment for stage or grade (adjusted HR 0·41, 95% CI 0·22-0·75), and in the COMPARZ clinical trial after adjustment for International Metastatic RCC Database (IMDC) risk score (0·68, 0·48-0·96). In the MSK immunotherapy cohort, the inverse association of BMI with mortality (HR 0·54, 95% CI 0·31-0·95) was not significant after adjustment for IMDC risk score (adjusted HR 0·72, 95% CI 0·40-1·30). Tumours of obese patients showed higher angiogenic scores on gene-set enrichment analysis-derived hallmark gene set angiogenesis signatures than did those of patients at a normal weight, but the degree of immune cell infiltration did not differ by BMI. We found increased peritumoral adipose tissue inflammation in obese patients relative to those at a normal weight, especially in peritumoral fat near the tumour. INTERPRETATION: We found aspects of the tumour microenvironment that vary by BMI in the tumour and peritumoral adipose tissue, which might contribute to the apparent survival advantage in obese patients with clear cell RCC compared with patients at a normal weight. The complex interplay between the clear cell RCC tumour and peritumoral adipose tissue microenvironment might have clinical relevance and warrants further investigation. FUNDING: Ruth L Kirschstein Research Service Award, American Society of Clinical Oncology Young Investigator Award, MSK's Ludwig Center, Weiss Family Kidney Research Fund, Novartis, The Sidney Kimmel Center for Prostate and Urologic Cancers, and the National Institutes of Health (National Cancer Institute) Cancer Center Support Grant.

Genomically annotated risk model for advanced renal-cell carcinoma: a retrospective cohort study.

BACKGROUND: The Memorial Sloan Kettering Cancer Center (MSKCC) risk model is an established prognostic tool for metastatic renal-cell carcinoma that integrates clinical and laboratory data, but is agnostic to tumour genomics. Several mutations, including BAP1 and PBRM1, have prognostic value in renal-cell carcinoma. Using two independent clinical trial datasets of patients with metastatic renal-cell carcinoma, we aimed to study whether the addition of the mutation status for several candidate prognostic genes to the MSKCC model could improve the model's prognostic performance. METHODS: In this retrospective cohort study, we used available formalin-fixed paraffin-embedded tumour tissue and clinical outcome data from patients with metastatic renal-cell carcinoma assigned to treatment with tyrosine kinase inhibitors in the COMPARZ trial (training cohort; n=357) and RECORD-3 trial (validation cohort; n=258). Eligible patients in both trials were treatment-naive; had histologically confirmed, advanced, or metastatic renal-cell carcinoma; and a Karnofsky performance status score of at least 70. For each cohort, data from patients in all treatment groups (sunitinib and pazopanib in the training cohort, and everolimus and sunitinib in the validation cohort) were pooled for this analysis. In the training cohort, tumour tissue was used to evaluate somatic mutations by next-generation sequencing, and the association between cancer-specific outcomes (overall survival, progression-free survival, and overall response) and the mutation status of six genes of interest (BAP1, PBRM1, TP53, TERT, KDM5C, and SETD2) was tested. Only those genes with prognostic value in this setting were added to the MSKCC risk model to create a genomically annotated version. The validation cohort was used to independently test the prognostic value of the annotated model compared with the original MSKCC risk model. FINDINGS: 357 (32%) of 1110 patients assigned to protocol treatment in the COMPARZ study between August, 2008, and September, 2011, were evaluable for mutation status and clinical outcomes in the training cohort. The independent validation cohort included 258 (55%) of 471 evaluable patients, enrolled between October, 2009, and June, 2011, on the RECORD-3 study. In the training cohort, the presence of any mutation in BAP1 or TP53, or both, and absence of any mutation in PBRM1 were prognostic in terms of overall survival (TP53wt/BAP1mut, TP53mut/BAP1wt o TP53mut/BAP1mut vs TP53wt/BAP1wt hazard ratio [HR] 1·57, 95% CI 1·21-2·04; p=0·0008; PBRM1wt vs PBRMmut, HR 1·58, 1·16-2·14; p=0·0035). The mutation status for these three prognostic genes were added to the original MSKCC risk model to create a genomically annotated version. Distribution of participants in the training cohort into the three risk groups of the original MSKCC model changed from 87 (24%) of 357 patients deemed at favourable risk, 217 (61%) at intermediate risk, and 53 (15%) at poor risk, to distribution across four risk groups in the genomically annotated risk model, with 36 (10%) of 357 deemed at favourable risk, 77 (22%) at good risk, 108 (30%) at intermediate risk, and 136 (38%) at poor risk. Addition of genomic information improved model performance for predicting overall survival (C-index: original model, 0·595 [95% CI 0·557-0·634] vs new model, 0·637 [0·595-0·679]) and progression-free survival (0·567 [95% CI 0·529-0·604] vs 0·602 [0·560-0·643]) with adequate discrimination of the proportion of patients who achieved an objective response (Cochran-Armitage one-sided p=0·0014). Analyses in the validation cohort confirmed the superiority of the genomically annotated risk model over the original version. INTERPRETATION: The mutation status of BAP1, PBRM1, and TP53 has independent prognostic value in patients with advanced or metastatic renal-cell carcinoma treated with first-line tyrosine kinase inhibitors. Improved stratification of patients across risk groups by use of a genomically annotated model including the mutational status of these three genes warrants further investigation in prospective trials and could be of use as a model to stratify patients with metastatic renal-cell carcinoma in clinical trials. FUNDING: Novartis Pharmaceuticals Corporation, MSKCC Support Grant/Core Grant, and the J Randall & Kathleen L MacDonald Research Fund.

Sample Site Impacts RNA Biomarkers for Renal Cell Carcinoma.

Immunotherapy (ICIs) remains a mainstay for treatment of advanced clear-cell renal cell carcinoma (ccRCC). Biomarker analyses have demonstrated that gene expression profiles are associated with regimen-specific outcomes. These transcriptomic analyses used mixed sample cohorts (primary and metastatic tumor specimens) and it is unknown whether the clinical relevance of transcriptomic signatures is impacted by tissue site. We evaluated data for 1132 patients with metastatic ccRCC treated with ICI in prior studies (IMmotion151 and CheckMate-009, -010, and -025). We identified significant and reproducible differences in gene expression by tissue site. We tested the association between previously described molecular tissue clusters (MTCs) by tissue site (MTC1-primary and MTC1-metastasis) and progression-free survival (PFS) and objective response to systemic therapy. In IMmotion151, MTC2-metastasis was significantly associated with better PFS on sunitinib (hazard ratio [HR] 3.39, 95% confidence interval [CI] 1.32-8.69; p = 0.01) in comparison to MTC2-primary (HR 0.95, 95% CI 0.65-1.38; p = 0.80; pinteraction = 0.02). Evaluation of known RNA signatures in the CheckMate trials revealed that JAVELIN-metastasis was associated with better PFS on ICI (HR 0.77, 95% CI 0.62-0.97; p = 0.03) in comparison to JAVELIN-primary (HR 1.04, 95% CI 0.91-1.19; p = 0.56; pinteraction = 0.02). These results indicate that tissue site may be a relevant confounder in biomarker analyses.

Effects of Vitamin D on tumor cell proliferation and migration, tumor initiation and anti-tumor immune response in head and neck squamous cell carcinomas.

BACKGROUND: Head and neck squamous cell carcinomas (HNSCCs) are among the six most common cancers, with a constantly poor prognosis. Vitamin D has been found to have antineoplastic and immunomodulatory properties in various cancers. This study investigated the impact of Vitamin D on the initiation and progression as well as antitumor immune response in HNSCCs, both in vitro and in vivo. METHODS: An immunocompetent, orthotopic oral carcinogenesis mouse model was used to examine the influence of Vitamin D3 substitution on HNSCC initiation and progression in vivo. Tumor immune infiltration was analyzed by immunohistochemistry targeting CD3, CD8, NKR-P1C, FOXP3, and CD163. Two HPV- and two HPV+ HNSCC cell lines were treated with 1,25-dihydroxyvitamin D3 to analyze effects on tumor cell proliferation, migration and transcriptomic changes using RNA-sequencing, differential gene expression and gene set enrichment analysis. RESULTS: Vitamin D3 treatment led to a significant suppression of HNSCC initiation and progression, while also stimulating tumor immune infiltration with CD3+, CD8+ and NKR-P1C+ cells and lowering levels of M2 macrophages and Treg cells in vivo. In vitro experiments showed an inhibition of HNSCC cell proliferation and migration in HPV+ and HPV- cell lines. RNA-sequencing showed significant regulations in IL6 JAK STAT3, hypoxia signaling and immunomodulatory pathways upon Vitamin D3 treatment. CONCLUSION: The findings of our study highlight the promising potential of Vitamin D in the therapeutic repertoire for HNSCC patients given its immune modulating, anti-proliferative and anti-migratory properties. Clinical transferability of those in vitro and in vivo effects should be further validated in clinical trials.

Phase 2 trial of regorafenib in recurrent or metastatic adenoid cystic carcinoma.

BACKGROUND: There is a significant need for effective therapies to treat recurrent/metastatic (R/M) adenoid cystic carcinoma (ACC). This study evaluated the multi-targeted, vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI) regorafenib in patients with R/M ACC. METHODS: Patients with progressive R/M ACC were treated with regorafenib until disease progression, consent withdrawal, or excessive toxicity. The primary endpoints were best overall response (BOR) and 6-month progression-free survival (PFS). Genomic and transcriptomic biomarker analyses were performed in tumors from trial participants. RESULTS: Thirty-eight patients were enrolled, including 7 (18%) patients with prior VEGFR-TKIs. No objective responses were observed. Six-month PFS was 45%, and median PFS was 7.2 months (95%CI 5.2-11.9 months). Presence of either activating NOTCH1 (22%) or KDM6A alterations (24%) was associated with decreased PFS (HR 2.6, 95%CI 1.1-6.1, p=0.03). Bulk RNA sequencing of pre-treatment tumors revealed that regorafenib clinical benefit (CB; PFS≥6 months; n=11) was associated with native enrichment of immune-related signatures. Immune deconvolution revealed a greater degree of macrophage and T-cell infiltration in CB tumors. Tumors from patients with no clinical benefit (NCB; PFS<6 months; n=9) had greater expression of signatures related to cell cycle progression (E2F targets, G2/M checkpoint). CONCLUSION: The trial failed to meet the pre-specified 6-month PFS and BOR targets. We hypothesize that TKI efficacy may be reliant upon an interplay between kinase inhibition and the ACC immune microenvironment, while programs promoting cell cycle progression may contribute to TKI resistance. These observations suggest that trials evaluating CDK4/6 inhibition plus a VEGFR-TKI should be considered.

Characterizing the Immune Microenvironment and Neoantigen Landscape of Hürthle Cell Carcinoma to Identify Potential Immunologic Vulnerabilities.

Hürthle cell carcinoma (HCC) is a rare type of thyroid cancer with high rates of distant metastasis and recurrence. Along with the scarcity of effective systemic therapies for HCC, these factors contribute to poor clinical outcomes. The immunologic features of HCC are poorly defined and response rates with immune checkpoint blockade have not been reported. A more comprehensive understanding of the immune landscape and factors that predict response to checkpoint inhibitors is needed. We performed RNA sequencing on 40 tumors to characterize the neoantigen landscape and immune microenvironment of HCC. We analyzed transcriptomic profiles, tumor-infiltrating immune cell populations, and measures of T-cell activation/dysfunction and correlated these to genetic features such as tumor mutation burden, neoantigen burden, mitochondrial mutations, and LOH from chromosomal uniparental disomy. Finally, immune profiles of patients with recurrence were compared with those of patients without recurrence. HCC tumors exhibited low levels of immune infiltration, with the more aggressive widely invasive phenotype associated with more immune depletion. There was a negative correlation between tumor mutation burden, neoantigen burden, programmed cell death ligand 1 (PD-L1) expression, and the immune infiltration score. HCC tumors that exhibited a global LOH from chromosomal uniparental disomy or haploidization had the lowest level of immune infiltration. HCC tumors that recurred displayed an immune-depleted microenvironment associated with global LOH and aerobic glycolysis. These findings offer new insights into the functional immune landscapes and immune microenvironment of HCC. Our data identify potential immunologic vulnerabilities for these understudied and often fatal cancers. Significance: The immune landscape of HCC is poorly defined and response rates to immunotherapy have not been reported. The authors found the immune microenvironment in HCC to be depleted. This immunosuppression is associated with a global LOH from haploidization and uniparental disomy, resulting in whole chromosome losses across the genome.

Patterns of immune equilibrium and escape in indolent and progressing tumors.

By comparing indolent/slowly progressing with aggressive/rapidly progressing tumor types, Pandey et al. identify human evidence of immune equilibrium in indolent tumors and immune escape in progressing tumors, suggesting a link between these mechanisms and the epidemiologic phenomenon of overdiagnosis.

Genomic and Transcriptomic Characteristics of Metastatic Thyroid Cancers with Exceptional Responses to Radioactive Iodine Therapy.

PURPOSE: The determinants of response or resistance to radioiodine (RAI) are unknown. We aimed to identify genomic and transcriptomic factors associated with structural responses to RAI treatment of metastatic thyroid cancer, which occur infrequently, and to test whether high MAPK pathway output was associated with RAI refractoriness. EXPERIMENTAL DESIGN: Exceptional response to RAI was defined as reduction of tumor volume based on RECIST v1.1. We performed a retrospective case-control study of genomic and transcriptomic characteristics of exceptional responders (ER; n = 8) versus nonresponders (NR; n = 16) matched by histologic type and stage at presentation on a 1:2 ratio. RESULTS: ER are enriched for mutations that activate MAPK through RAF dimerization (RAS, class 2 BRAF, RTK fusions), whereas NR are associated with BRAFV600E, which signals as a monomer and is unresponsive to negative feedback. ER have a lower MAPK transcriptional output and a higher thyroid differentiation score (TDS) than NR (P < 0.05). NR are enriched for 1q-gain (P < 0.05) and mutations of genes regulating mRNA splicing and the PI3K pathway. BRAFV600E tumors with 1q-gain have a lower TDS than BRAFV600E/1q-quiet tumors and transcriptomic signatures associated with metastatic propensity. CONCLUSIONS: ER tumors have a lower MAPK output and higher TDS than NR, whereas NR have a high frequency of BRAFV600E and 1q-gain. Molecular profiling of thyroid cancers and further functional validation of the key findings discriminating ER from NR may help predict response to RAI therapy.

Novel Genetic Subtypes of Urothelial Carcinoma With Differential Outcomes on Immune Checkpoint Blockade.

PURPOSE: Immune checkpoint blockade (ICB) therapy has significantly improved clinical outcomes in bladder cancer. Identification of correlates of benefit is critical to select appropriate therapy for individual patients. METHODS: To reveal genetic variables associated with benefit from ICB, we performed whole-exome sequencing on tumor specimens from 88 patients with advanced bladder cancer treated with ICB. RESULTS: We identified several genetic factors that correlated with progression-free and overall survival after ICB therapy including ARID1A mutation, tumor mutational burden, intratumoral heterogeneity, the ratio of nonsynonymous to synonymous mutations in the immunopeptidome (immune dN/dS), and tumor cell purity. In addition, we noted that neutrophil-to-lymphocyte ratio and smoking history were negatively associated with overall survival. These genetic characteristics define four molecular subtypes demonstrating differential sensitivity to ICB. We validated the association of these four subtypes with clinical benefit from ICB in an independent cohort (IMvigor210). Finally, we showed that these molecular subtypes also correlate with outcome, although with distinct relationships, among patients not treated with ICB using The Cancer Genome Atlas (TCGA) bladder cancer cohort. Using parallel RNA sequencing data, the subtypes were also shown to correlate with immune infiltration and inflammation, respectively, in the IMvigor210 and TCGA cohorts. CONCLUSION: Together, our study defines molecular subgroups of bladder cancer that influence benefit from ICB.

A multimodal atlas of tumour metabolism reveals the architecture of gene-metabolite covariation.

Tumour metabolism is controlled by coordinated changes in metabolite abundance and gene expression, but simultaneous quantification of metabolites and transcripts in primary tissue is rare. To overcome this limitation and to study gene-metabolite covariation in cancer, we assemble the Cancer Atlas of Metabolic Profiles of metabolomic and transcriptomic data from 988 tumour and control specimens spanning 11 cancer types in published and newly generated datasets. Meta-analysis of the Cancer Atlas of Metabolic Profiles reveals two classes of gene-metabolite covariation that transcend cancer types. The first corresponds to gene-metabolite pairs engaged in direct enzyme-substrate interactions, identifying putative genes controlling metabolite pool sizes. A second class of gene-metabolite covariation represents a small number of hub metabolites, including quinolinate and nicotinamide adenine dinucleotide, which correlate to many genes specifically expressed in immune cell populations. These results provide evidence that gene-metabolite covariation in cellularly heterogeneous tissue arises, in part, from both mechanistic interactions between genes and metabolites, and from remodelling of the bulk metabolome in specific immune microenvironments.

Activation of the EGFR/PI3K/AKT pathway limits the efficacy of trametinib treatment in head and neck cancer.

Blocking the mitogen-activated protein kinase (MAPK) pathway with the MEK1/2 inhibitor trametinib has produced promising results in patients with head and neck squamous cell carcinoma (HNSCC). In the current study, we showed that trametinib treatment leads to overexpression and activation of the epidermal growth factor receptor (EGFR) in HNSCC cell lines and patient-derived xenografts. Knockdown of EGFR improved trametinib treatment efficacy both in vitro and in vivo. Mechanistically, we demonstrated that trametinib-induced EGFR overexpression hyperactivates the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. In vitro, blocking the PI3K pathway with GDC-0941 (pictilisib), or BYL719 (alpelisib), prevented AKT pathway hyperactivation and enhanced the efficacy of trametinib in a synergistic manner. In vivo, a combination of trametinib and BYL719 showed superior antitumor efficacy vs. the single agents, leading to tumor growth arrest. We confirmed our findings in a syngeneic murine head and neck cancer cell line in vitro and in vivo. Taken together, our findings show that trametinib treatment induces hyperactivation of EGFR/PI3K/AKT; thus, blocking of the EGFR/PI3K pathway is required to improve trametinib efficacy in HNSCC.

Immunometabolic coevolution defines unique microenvironmental niches in ccRCC.

Tumor cell phenotypes and anti-tumor immune responses are shaped by local metabolite availability, but intratumoral metabolite heterogeneity (IMH) and its phenotypic consequences remain poorly understood. To study IMH, we profiled tumor/normal regions from clear cell renal cell carcinoma (ccRCC) patients. A common pattern of IMH transcended all patients, characterized by correlated fluctuations in the abundance of metabolites and processes associated with ferroptosis. Analysis of intratumoral metabolite-RNA covariation revealed that the immune composition of the microenvironment, especially the abundance of myeloid cells, drove intratumoral metabolite variation. Motivated by the strength of RNA-metabolite covariation and the clinical significance of RNA biomarkers in ccRCC, we inferred metabolomic profiles from the RNA sequencing data of ccRCC patients enrolled in 7 clinical trials, and we ultimately identifyied metabolite biomarkers associated with response to anti-angiogenic agents. Local metabolic phenotypes, therefore, emerge in tandem with the immune microenvironment, influence ongoing tumor evolution, and are associated with therapeutic sensitivity.