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Abstract Structural variation heavily influences the molecular landscape of cancer, in part by impacting DNA methylation-mediated transcriptional regulation. Here, using multi-omic datasets involving >2400 pediatric brain and central nervous system tumors of diverse histologies from the Children’s Brain Tumor Network, we report hundreds of genes and associated CpG islands (CGIs) for which the nearby presence of somatic structural variant (SV) breakpoints is recurrently associated with altered expression or DNA methylation, respectively, including tumor suppressor genes ATRX and CDKN2A. Altered DNA methylation near enhancers associates with nearby somatic SV breakpoints, including MYC and MYCN. A subset of genes with SV-CGI methylation associations also have expression associations with patient survival, including BCOR, TERT, RCOR2, and PDLIM4. DNA methylation changes in recurrent or progressive tumors compared to the initial tumor within the same patient can predict survival in pediatric and adult cancers. Our comprehensive and pan-histology genomic analyses reveal mechanisms of noncoding alterations impacting cancer genes.

Abstract SMARCB1 loss has long been observed in many solid tumors. However, there is a need to elucidate targetable pathways driving growth and metastasis in SMARCB1-deficient tumors. Here, we demonstrate that SMARCB1 deficiency, defined as genomic SMARCB1 copy number loss associated with reduced mRNA, drives disease progression in patients with bladder cancer by engaging STAT3. SMARCB1 loss increases the chromatin accessibility of the STAT3 locus in vitro. Orthotopically implanted SMARCB1 knockout (KO) cell lines exhibit increased tumor growth and metastasis. SMARCB1-deficient tumors show an increased IL6/JAK/STAT3 signaling axis in in vivo models and patients. Furthermore, a pSTAT3 selective inhibitor, TTI-101, reduces tumor growth in SMARCB1 KO orthotopic cell line-derived xenografts and a SMARCB1-deficient patient derived xenograft model. We have identified a gene signature generated from SMARCB1 KO tumors that predicts SMARCB1 deficiency in patients. Overall, these findings support the clinical evaluation of STAT3 inhibitors for the treatment of SMARCB1-deficient bladder cancer.

Abstract Both proteome and transcriptome data can help assess the relevance of non-coding somatic mutations in cancer. Here, we combine mass spectrometry-based proteomics data with whole genome sequencing data across 1307 human tumors spanning various tissues to determine the extent somatic structural variant (SV) breakpoint patterns impact protein expression of nearby genes. We find that about 25% of the hundreds of genes with SV-associated cis-regulatory alterations at the mRNA level are similarly associated at the protein level. SVs associated with enhancer hijacking, retrotransposon translocation, altered DNA methylation, or fusion transcripts are implicated in protein over-expression. SVs combined with altered protein levels considerably extend the numbers of patients with tumors somatically altered for critical pathways. We catalog both SV breakpoint patterns involving patient survival and genes with nearby SV breakpoints associated with increased cell dependency in cancer cell lines. Pan-cancer proteogenomics identifies targetable non-coding alterations, by virtue of the associated deregulated genes.

Forkhead transcription factor FoxF2 plays a crucial role in the development of organs derived from primitive gut. Here the authors show that reduction of Foxf2 expression in stromal cells is associated with high grade prostate cancer and that increasing prostatic stromal Foxf2 sensitizes prostate cancer to immune checkpoint blockade.

Pan-cancer proteomics analysis enables the analysis of protein expression across multiple cancer types. Here, the authors compare proteomics from 14 cancer types and show 11 distinct subtypes across multiple cancer types. Proteome data could link higher pathway activity levels with somatic alteration of specific genes in the pathway.

PI3K inhibitors have limited efficacy in triple negative breast cancer (TNBC). Here, the authors show that MAPK4 activates AKT independent of PI3K and thus promotes tumour growth in a subset of TNBC and that MAPK4 inhibition sensitizes to PI3K blockade in these tumours.’

The way in which metastatic tumour cells control endocytic vesicular trafficking networks to establish a front-rear polarity axis that facilitates motility remains unclear. Here, the authors show that the EMT activator ZEB1 influences vesicular trafficking dynamics to execute cell polarity change.

Building on the known role of BMP signalling in implantation, the authors define the role of uterine ACVR2A and ALK3 (via SMAD1/5) in vivo in regulating murine endometrial receptivity and embryo implantation.

The global impact of somatic structural variants (SSVs) on gene expression in childhood cancers is unclear. Here, the authors analyse cancer genome and RNA sequencing data of 854 pediatric brain tumours and report a landscape of genes deregulated by SSVs.

The mechanisms associated with Caveolin-1 (Cav-1) mediated metabolic changes in prostate cancer are unclear. Here, the authors show that Cav-1 promotes rewiring of cancer cell lipid metabolism towards a program of exogenous lipid scavenging and vesicle biogenesis that intersects with mitochondrial dynamics in prostate tumors.

In this study the authors consider the structural variants (SVs) present within cancer cases of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. They report hundreds of genes, including known cancer-associated genes for which the nearby presence of a SV breakpoint is associated with altered expression.

Mass-spectrometry-based profiling can be used to stratify tumours into molecular subtypes. Here, by classifying over 500 tumours, the authors show that this approach reveals proteomic subgroups which cut across tumour types.

Non-small cell lung cancer (NSCLC) is often associated with metastasis to the lungs. Here, the authors perform independent screens and identify NuRD as a co-repressor of ZEB1, and demonstrate TBC1D2b as a downstream target of ZEB1/NuRD complex regulating NSCLC metastasis.

LKB1 is frequently mutated in lung squamous cell carcinomas. Here, the authors show that sole LKB1 depletion is sufficient to drive the development of this cancer, where downstream defective MKK7-JNK1/2 signalling activates the ∆Np63/p63 pathway to induce subsequent epithelial cells transformation and tumour progression.

One of the major causes of cancer-related mortality is represented by metastatic lung cancer. Here the authors characterize the role of TMEM106B in driving metastatic lung adenocarcinoma and suggest that TMEM106B-mediated secretion of cathespin impacts cell migration and invasion of lung cancer cells, increasing metastatic spreading.

KRAS-driven lung cancers represent an aggressive form of NSCLC. In this study the authors perform an in vivo functional screening and identify GATAD2B as a driver of tumor growth and metastasis in KRAS-driven lung cancer.

ATRX inactivation frequently occurs in glioma. Here, the authors explore the role of ATRX inactivation in oncogenesis, highlighting ATRX deficiency driven epigenomic changes that influence the expression of genes crucial to the oncogenic phenotype.

Urological cancers have disparate tissues and cells of origin but share many molecular features. Here, the authors use multidimensional and comprehensive molecular characterization to classify urological cancers into nine major genomic subtypes, highlighting potential therapeutic targets.

ZEB1 is a driver of epithelial-to-mesenchymal transition that usually promotes lung cancer in the context of KRAS mutation. Here, the authors uncover a growth suppressive role for ZEB1 in EGFRmutant lung adenocarcinoma, thus elucidating the context dependent function of this protein.

The orphan nuclear receptor COUP-TFII is highly expressed in metastatic prostate cancers and its overexpression accelerates prostate tumour progression in mouse models. Here, the author show that that loss of miR-101 and miR-27a in prostate cancer cells can lead to COUP-TFII expression which in turn directly regulates FOXM1 and CENPFfavouring prostate cancer metastasis.

Next generation sequencing allows the identification of oncogenic driver genes in pancreatic cancer. Here, in an effort to identify additional causal genes, the authors develop a high throughput in vivoscreen and identify genes that whilst infrequently mutated in pancreatic cancer contribute to tumour formation.