ABSTRACT
Comprehensive genomic studies have delineated key driver mutations linked to disease progression for most cancers. However, corresponding transcriptional changes remain largely elusive because of the bias associated with cross-study analysis. Here, we overcome these hurdles and generate a comprehensive prostate cancer transcriptome atlas that describes the roadmap to tumor progression in a qualitative and quantitative manner. Most cancers follow a uniform trajectory characterized by upregulation of polycomb-repressive-complex-2, G2-M checkpoints, and M2 macrophage polarization. Using patient-derived xenograft models, we functionally validate our observations and add single-cell resolution. Thereby, we show that tumor progression occurs through transcriptional adaption rather than a selection of pre-existing cancer cell clusters. Moreover, we determine at the single-cell level how inhibition of EZH2 - the top upregulated gene along the trajectory - reverts tumor progression and macrophage polarization. Finally, a user-friendly web-resource is provided enabling the investigation of dynamic transcriptional perturbations linked to disease progression.
Subject(s)
Enhancer of Zeste Homolog 2 Protein/genetics , Neoplasm Proteins/genetics , Prostatic Neoplasms/genetics , Transcriptome , Animals , Atlases as Topic , Cell Line, Tumor , Disease Progression , Enhancer of Zeste Homolog 2 Protein/metabolism , G2 Phase Cell Cycle Checkpoints/genetics , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Heterografts , Humans , Macrophages/metabolism , Macrophages/pathology , Male , Mice , Neoplasm Proteins/metabolism , Polycomb Repressive Complex 2/genetics , Polycomb Repressive Complex 2/metabolism , Principal Component Analysis , Prostate/metabolism , Prostate/pathology , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Signal Transduction , Single-Cell AnalysisABSTRACT
Driver genes with a mutually exclusive mutation pattern across tumor genomes are thought to have overlapping roles in tumorigenesis. In contrast, we show here that mutually exclusive prostate cancer driver alterations involving the ERG transcription factor and the ubiquitin ligase adaptor SPOP are synthetic sick. At the molecular level, the incompatible cancer pathways are driven by opposing functions in SPOP. ERG upregulates wild type SPOP to dampen androgen receptor (AR) signaling and sustain ERG activity through degradation of the bromodomain histone reader ZMYND11. Conversely, SPOP-mutant tumors stabilize ZMYND11 to repress ERG-function and enable oncogenic androgen receptor signaling. This dichotomy regulates the response to therapeutic interventions in the AR pathway. While mutant SPOP renders tumor cells susceptible to androgen deprivation therapies, ERG promotes sensitivity to high-dose androgen therapy and pharmacological inhibition of wild type SPOP. More generally, these results define a distinct class of antagonistic cancer drivers and a blueprint toward their therapeutic exploitation.
Subject(s)
Nuclear Proteins/metabolism , Oncogene Proteins/metabolism , Prostatic Neoplasms/metabolism , Repressor Proteins/metabolism , Transcriptional Regulator ERG/metabolism , Ubiquitin-Protein Ligase Complexes/metabolism , Animals , Biomarkers, Tumor/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Co-Repressor Proteins/genetics , Co-Repressor Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , HEK293 Cells , Humans , Immunohistochemistry , Immunoprecipitation , Male , Mice , Mice, Nude , Mutation/genetics , Nuclear Proteins/genetics , Oncogene Proteins/genetics , Prostatic Neoplasms/genetics , Protein Binding , Proteomics , Receptors, Androgen/metabolism , Repressor Proteins/genetics , Signal Transduction/physiology , Transcriptional Regulator ERG/genetics , Ubiquitin-Protein Ligase Complexes/geneticsABSTRACT
PURPOSE: CXCR4 receptor and its unique ligand, the CXCL12 chemokine, have been recently implicated in cancer metastasis. Evidence about the role of CXCR4/CXCL12 axis has been reported in several cancers including melanoma. Our goal was to investigate if CXCR4 expression has a prognostic value in malignant melanoma. EXPERIMENTAL DESIGN: Immunohistochemical expression of CXCR4 was evaluated on 71 specimens of primary cutaneous melanoma with a Breslow tumor thickness of >1 mm after radical resection. Associations between baseline patient features and tumors were analyzed by chi(2) test. The prognostic value of CXCR4 expression was evaluated by univariate and multivariate analyses adjusted by age, sex, Breslow tumor thickness, presence of ulceration, and sentinel lymph node metastases. RESULTS: CXCR4 expression was detected in 31 of 71 (43.6%) primary cutaneous melanomas. Membrane or cytoplasmic staining for CXCR4 protein was absent in 56% of the tumors. The positive cases were divided into three score classes according to their staining: low in 15 cases (21%), moderate in 10 (14%), and high in 6 (8%). After a median follow-up of 38 months, 26 patients progressed (16 of 26 expressed CXCR4) and 19 died (12 of 19 expressed CXCR4). The CXCR4 expression on tumor cells was correlated with an unfavorable prognosis with a median disease-free and overall survival of 22 and 35 months, respectively. The hazard ratios of relapse and death, compared with patients with CXCR4-negative tumors, were 2.5 (95% confidence interval, 1.2-6.1) and 3.1 (95% confidence interval, 1.1-7.2), respectively. Median time-to-event (progression and survival) was not reached in patients with CXCR4-negative tumors. In the multivariate analysis, CXCR4 expression, presence of ulceration, and sentinel lymph node status emerged as independent prognostic factors. CONCLUSIONS: This article provides the first evidence that CXCR4 expression could be an independent and powerful prognostic marker in primary cutaneous malignant melanomas.
