Targeting TRIP13 in favorable histology Wilms tumor with nuclear export inhibitors synergizes with doxorubicin.

Wilms tumor (WT) is the most common renal malignancy of childhood. Despite improvements in the overall survival, relapse occurs in ~15% of patients with favorable histology WT (FHWT). Half of these patients will succumb to their disease. Identifying novel targeted therapies remains challenging in part due to the lack of faithful preclinical in vitro models. Here we establish twelve patient-derived WT cell lines and demonstrate that these models faithfully recapitulate WT biology using genomic and transcriptomic techniques. We then perform loss-of-function screens to identify the nuclear export gene, XPO1, as a vulnerability. We find that the FDA approved XPO1 inhibitor, KPT-330, suppresses TRIP13 expression, which is required for survival. We further identify synergy between KPT-330 and doxorubicin, a chemotherapy used in high-risk FHWT. Taken together, we identify XPO1 inhibition with KPT-330 as a potential therapeutic option to treat FHWTs and in combination with doxorubicin, leads to durable remissions in vivo.

KEAP1/NFE2L2 Mutations Predict Lung Cancer Radiation Resistance That Can Be Targeted by Glutaminase Inhibition.

Tumor genotyping is not routinely performed in localized non-small cell lung cancer (NSCLC) due to lack of associations of mutations with outcome. Here, we analyze 232 consecutive patients with localized NSCLC and demonstrate that KEAP1 and NFE2L2 mutations are predictive of high rates of local recurrence (LR) after radiotherapy but not surgery. Half of LRs occurred in tumors with KEAP1/NFE2L2 mutations, indicating that they are major molecular drivers of clinical radioresistance. Next, we functionally evaluate KEAP1/NFE2L2 mutations in our radiotherapy cohort and demonstrate that only pathogenic mutations are associated with radioresistance. Furthermore, expression of NFE2L2 target genes does not predict LR, underscoring the utility of tumor genotyping. Finally, we show that glutaminase inhibition preferentially radiosensitizes KEAP1-mutant cells via depletion of glutathione and increased radiation-induced DNA damage. Our findings suggest that genotyping for KEAP1/NFE2L2 mutations could facilitate treatment personalization and provide a potential strategy for overcoming radioresistance conferred by these mutations. SIGNIFICANCE: This study shows that mutations in KEAP1 and NFE2L2 predict for LR after radiotherapy but not surgery in patients with NSCLC. Approximately half of all LRs are associated with these mutations and glutaminase inhibition may allow personalized radiosensitization of KEAP1/NFE2L2-mutant tumors.This article is highlighted in the In This Issue feature, p. 1775.

Noninvasive Early Identification of Therapeutic Benefit from Immune Checkpoint Inhibition.

Although treatment of non-small cell lung cancer (NSCLC) with immune checkpoint inhibitors (ICIs) can produce remarkably durable responses, most patients develop early disease progression. Furthermore, initial response assessment by conventional imaging is often unable to identify which patients will achieve durable clinical benefit (DCB). Here, we demonstrate that pre-treatment circulating tumor DNA (ctDNA) and peripheral CD8 T cell levels are independently associated with DCB. We further show that ctDNA dynamics after a single infusion can aid in identification of patients who will achieve DCB. Integrating these determinants, we developed and validated an entirely noninvasive multiparameter assay (DIREct-On, Durable Immunotherapy Response Estimation by immune profiling and ctDNA-On-treatment) that robustly predicts which patients will achieve DCB with higher accuracy than any individual feature. Taken together, these results demonstrate that integrated ctDNA and circulating immune cell profiling can provide accurate, noninvasive, and early forecasting of ultimate outcomes for NSCLC patients receiving ICIs.

Integrating genomic features for non-invasive early lung cancer detection.

Radiologic screening of high-risk adults reduces lung-cancer-related mortality1,2; however, a small minority of eligible individuals undergo such screening in the United States3,4. The availability of blood-based tests could increase screening uptake. Here we introduce improvements to cancer personalized profiling by deep sequencing (CAPP-Seq)5, a method for the analysis of circulating tumour DNA (ctDNA), to better facilitate screening applications. We show that, although levels are very low in early-stage lung cancers, ctDNA is present prior to treatment in most patients and its presence is strongly prognostic. We also find that the majority of somatic mutations in the cell-free DNA (cfDNA) of patients with lung cancer and of risk-matched controls reflect clonal haematopoiesis and are non-recurrent. Compared with tumour-derived mutations, clonal haematopoiesis mutations occur on longer cfDNA fragments and lack mutational signatures that are associated with tobacco smoking. Integrating these findings with other molecular features, we develop and prospectively validate a machine-learning method termed 'lung cancer likelihood in plasma' (Lung-CLiP), which can robustly discriminate early-stage lung cancer patients from risk-matched controls. This approach achieves performance similar to that of tumour-informed ctDNA detection and enables tuning of assay specificity in order to facilitate distinct clinical applications. Our findings establish the potential of cfDNA for lung cancer screening and highlight the importance of risk-matching cases and controls in cfDNA-based screening studies.

Circulating Tumor DNA Analysis to Assess Risk of Progression after Long-term Response to PD-(L)1 Blockade in NSCLC.

PURPOSE: Treatment with PD-(L)1 blockade can produce remarkably durable responses in patients with non-small cell lung cancer (NSCLC). However, a significant fraction of long-term responders ultimately progress and predictors of late progression are unknown. We hypothesized that circulating tumor DNA (ctDNA) analysis of long-term responders to PD-(L)1 blockade may differentiate those who will achieve ongoing benefit from those at risk of eventual progression. EXPERIMENTAL DESIGN: In patients with advanced NSCLC achieving long-term benefit from PD-(L)1 blockade (progression-free survival ≥ 12 months), plasma was collected at a surveillance timepoint late during/after treatment to interrogate ctDNA by Cancer Personalized Profiling by Deep Sequencing. Tumor tissue was available for 24 patients and was profiled by whole-exome sequencing (n = 18) or by targeted sequencing (n = 6). RESULTS: Thirty-one patients with NSCLC with long-term benefit to PD-(L)1 blockade were identified, and ctDNA was analyzed in surveillance blood samples collected at a median of 26.7 months after initiation of therapy. Nine patients also had baseline plasma samples available, and all had detectable ctDNA prior to therapy initiation. At the surveillance timepoint, 27 patients had undetectable ctDNA and 25 (93%) have remained progression-free; in contrast, all 4 patients with detectable ctDNA eventually progressed [Fisher P < 0.0001; positive predictive value = 1, 95% confidence interval (CI), 0.51-1; negative predictive value = 0.93 (95% CI, 0.80-0.99)]. CONCLUSIONS: ctDNA analysis can noninvasively identify minimal residual disease in patients with long-term responses to PD-(L)1 blockade and predict the risk of eventual progression. If validated, ctDNA surveillance may facilitate personalization of the duration of immune checkpoint blockade and enable early intervention in patients at high risk for progression.

Synthetic Lethal Interaction of SHOC2 Depletion with MEK Inhibition in RAS-Driven Cancers.

The mitogen-activated protein kinase (MAPK) pathway is a critical effector of oncogenic RAS signaling, and MAPK pathway inhibition may be an effective combination treatment strategy. We performed genome-scale loss-of-function CRISPR-Cas9 screens in the presence of a MEK1/2 inhibitor (MEKi) in KRAS-mutant pancreatic and lung cancer cell lines and identified genes that cooperate with MEK inhibition. While we observed heterogeneity in genetic modifiers of MEKi sensitivity across cell lines, several recurrent classes of synthetic lethal vulnerabilities emerged at the pathway level. Multiple members of receptor tyrosine kinase (RTK)-RAS-MAPK pathways scored as sensitizers to MEKi. In particular, we demonstrate that knockout, suppression, or degradation of SHOC2, a positive regulator of MAPK signaling, specifically cooperated with MEK inhibition to impair proliferation in RAS-driven cancer cells. The depletion of SHOC2 disrupted survival pathways triggered by feedback RTK signaling in response to MEK inhibition. Thus, these findings nominate SHOC2 as a potential target for combination therapy.

Nonalcoholic Fatty Liver Disease Demonstrates a Pre-fibrotic and Premalignant Molecular Signature.

BACKGROUND: Metabolic syndrome contributing to nonalcoholic fatty liver disease (NAFLD) can lead to hepatic dysfunction, steatohepatitis, cirrhosis, and hepatocellular carcinoma. AIMS: In this study, we tested whether diet-induced fatty liver in a mouse model physiologically mimicked human NAFLD, and whether transcriptional alterations in mouse fatty liver signified risk for the development of hepatitis, cirrhosis, and/or hepatocellular carcinoma. METHODS: SAMP6 strain mice were fed a low-fat diet or high-fat diet (HFD) for 6 months. Mouse livers were isolated and subjected to histology, immunohistochemistry, and whole transcriptome RNA sequencing. Sequences were aligned to the mouse reference genome, and gene expression signatures were analyzed using bioinformatics tools including Cufflinks, Pathview, Cytoscape, ClueGO, and GOstats. RESULTS: Consistent with NAFLD, livers from HFD-fed mice demonstrated steatosis, high levels of inflammation, an up-regulation of genes encoding proteins associated with the complement pathway and immune responses, and down-regulation of those associated with metabolic processes. These livers also showed an up-regulation of genes associated with fibrosis and malignant transformation but no histological evidence of either pathobiology or DNA damage. CONCLUSIONS: HFD-fed mice exhibited NAFLD that had incompletely transitioned from fatty liver to NASH. Importantly, bioinformatics approaches identified pre-fibrotic and premalignant signatures, suggesting that the pathogenesis of both fibrosis and cancer may initiate in fatty livers well before associated histological changes are evident.

CXCL12/CXCR4-Mediated Procollagen Secretion Is Coupled To Cullin-RING Ubiquitin Ligase Activation.

Tissue fibrosis is mediated by the actions of multiple pro-fibrotic proteins that can induce myofibroblast phenoconversion through diverse signaling pathways coupled predominantly to Smads or MEK/Erk proteins. The TGFß/TGFßR and CXCL12/CXCR4 axes induce myofibroblast phenoconversion independently through Smads and MEK/Erk proteins, respectively. To investigate these mechanisms at the genetic level, we have now elucidated the TGFß/TGFßR and CXCL12/CXCR4 transcriptomes in human fibroblasts. These transcriptomes are largely convergent, and up-regulate transcripts encoding proteins known to promote myofibroblast phenoconversion. These studies also revealed a molecular signature unique to CXCL12/CXCR4 axis activation for COPII vesicle formation, ubiquitination, and Golgi/ER localization/targeting. In particular, both CUL3 and KLHL12, key members of the Cullin-RING (CRL) ubiquitin ligase family of proteins involved in procollagen transport from the ER to the Golgi, were highly up-regulated in CXCL12-, but repressed in TGFß-, treated cells. Up-regulation of CUL3 and KLHL12 was correlated with higher procollagen secretion by CXCL12-treated cells, and this affect was ablated upon treatment with inhibitors specific for CXCR4 or CUL3 and repressed by TGFß/TGFßR axis activation. The results of these studies show that activation of the CXCL12/CXCR4 axis uniquely facilitates procollagen I secretion through a COPII-vesicle mediated mechanism to promote production of the ECM characteristic of fibrosis.

CXCL12/CXCR4 Axis Activation Mediates Prostate Myofibroblast Phenoconversion through Non-Canonical EGFR/MEK/ERK Signaling.

Benign prostate hyperplasia (BPH), an enlargement of the prostate common in aging in men, is associated with urinary voiding dysfunction manifest as Lower Urinary Tract Symptoms (LUTS). Although inflammation and abnormal smooth muscle contractions are known to play key roles in the development of LUTS, tissue fibrosis may also be an important and previously unrecognized contributing factor. Tissue fibrosis arises from the unregulated differentiation of fibroblasts or other precursor cell types into myofibroblasts, which is usually accomplished by activation of the TGFß/TGFßR axis. Previously we reported that the CXC-type chemokines, CXCL5, CXCL8 and CXCL12, which are up-regulated in the aging in the prostate, can drive this differentiation process as well in the absence of TGFß. Based on this data we sought to elucidate the molecular mechanisms employed by CXCL12, and its receptor CXCR4, during prostate myofibroblast phenoconversion. The results of these studies suggest that CXCL12/CXCR4-mediated signaling events in prostate myofibroblast phenoconversion may proceed through non-canonical pathways that do not depend on TGFß/TGFßR axis activation or Smad signaling. Here we report that CXCL12/CXCR4 axis activation promotes signaling through the EGFR and downstream MEK/ERK and PI3K/Akt pathways during myofibroblast phenoconversion, but not through TGFß/TGFßR and downstream Smad signaling, in prostate fibroblasts undergoing myofibroblast phenoconversion. We document that EGFR transactivation is required for CXCL12-mediated signaling and expression of genes associate with myofibroblast phenoconversion (α-SMA, COL1a1). Our study successfully identified TGFß/TGFßR-independent molecular mechanisms that promote CXCL12/CXCR4-induced myofibroblast phenoconversion. This information may be crucial for the development of novel therapies and potential biomarkers for prostatic fibrosis.