Comprehensive transcriptomic analysis of prostate cancer lung metastases.

Metastatic prostate cancer (mPCa) is a widespread disease with high mortality. Unraveling molecular mechanisms of disease progression is of utmost importance. The microenvironment in visceral organs and the skeletal system is of particular interest as a harbinger of metastatic spread. Therefore, we performed a comprehensive transcriptomic analysis of prostate cancer lung metastases with a special focus on differentially expressed genes attributable to the microenvironment. Digital gene expression analysis using the NanoString nCounter analysis system was performed on formalin-fixed, paraffin-embedded (FFPE) tissue from prostate cancer (PCa) lung metastases (n = 24). Data were compared to gene expression data from primary PCa and PCa bone metastases. Bioinformatic analysis was performed using several publicly available tools. In comparison to prostate cancer bone metastases, 209 genes were significantly upregulated, and 100 genes were significantly downregulated in prostate cancer lung metastases. Among the up-regulated genes, the top 10 genes with the most significant P-value were HLA-DPB1, PTPRC, ITGB7, C3, CCL21, CCL5, ITGAM, SERPINA1, MFAP4, ARAP2 and among the down-regulated genes, the top 10 genes with the most significant P-value were FOXC2, TWIST1, CDK14, CHAD, IBSP, EPN3, VIT, HAPLN1, SLC44A4, TBX1. In PCa lung metastases genes associated with immunogenic responses were upregulated while genes associated with epithelial-mesenchymal transition were down-regulated. We also showed that CXCR3/CXCL10 axis plays a significant role in prostate cancer lung metastases in comparison to bone metastases. In this study, we comprehensively explored transcriptomic alterations in PCa lung metastases in comparison to primary PCa and PCa bone metastases. In PCa lung metastases genes associated with immunogenic responses are upregulated while genes associated with epithelial-mesenchymal transition are down-regulated. This points to a more immunogenic phenotype of PCa lung metastases thus potentially making patients more susceptible to immunotherapeutic approaches.

Dermatomyositis-like skin eruptions under hydroxyurea therapy conceal TP53-mutated atypical keratinocytes: A histopathologic and molecular pathologic case series.

Hydroxyurea is an antimetabolite that inhibits DNA synthesis and is used as a treatment option in chronic myeloproliferative disorders. Rarely, "dermatomyositis (DM)-like" skin lesions are observed after long-term therapy. In this case series, five skin biopsies of four patients were evaluated by histology, immunohistochemistry, and next-generation sequencing of the TP53 gene locus. All biopsies showed focal basal pleomorphic keratinocytes and suprabasal aberrant p53 expression as well as sparse to severe vacuolar interface dermatitis. Histopathologically, "DM-like" skin lesions can be clearly distinguished from DM by marked subepidermal fibrosis, vascular proliferation, and the absence of dermal mucin deposits. In 75% of the specimens multiple, partly inactivating and/or pathogenic point mutations of TP53 were found in low frequencies. "DM-like" skin eruptions as a long-term consequence of hydroxyurea therapy are possibly not chemotherapy-associated benign toxic changes, but rather inflammatory reactions to complex keratinocyte alterations that clinically mimic the picture of DM. Synergistic mutagenic effects of hydroxyurea and sunlight might be responsible for this unique drug side effect and could provide a pathogenic link to the known increased risk of skin cancer in these patients.

Next-Generation Rapid Autopsies Enable Tumor Evolution Tracking and Generation of Preclinical Models.

PURPOSE: Patients with cancer who graciously consent for autopsy represent an invaluable resource for the study of cancer biology. To advance the study of tumor evolution, metastases, and resistance to treatment, we developed a next-generation rapid autopsy program integrated within a broader precision medicine clinical trial that interrogates pre- and postmortem tissue samples for patients of all ages and cancer types. MATERIALS AND METHODS: One hundred twenty-three (22%) of 554 patients who consented to the clinical trial also consented for rapid autopsy. This report comprises the first 15 autopsies, including patients with metastatic carcinoma (n = 10), melanoma (n = 1), and glioma (n = 4). Whole-exome sequencing (WES) was performed on frozen autopsy tumor samples from multiple anatomic sites and on non-neoplastic tissue. RNA sequencing (RNA-Seq) was performed on a subset of frozen samples. Tissue was also used for the development of preclinical models, including tumor organoids and patient-derived xenografts. RESULTS: Three hundred forty-six frozen samples were procured in total. WES was performed on 113 samples and RNA-Seq on 72 samples. Successful cell strain, tumor organoid, and/or patient-derived xenograft development was achieved in four samples, including an inoperable pediatric glioma. WES data were used to assess clonal evolution and molecular heterogeneity of tumors in individual patients. Mutational profiles of primary tumors and metastases yielded candidate mediators of metastatic spread and organotropism including CUL9 and PIGM in metastatic ependymoma and ANKRD52 in metastatic melanoma to the lung. RNA-Seq data identified novel gene fusion candidates. CONCLUSION: A next-generation sequencing-based autopsy program in conjunction with a pre-mortem precision medicine pipeline for diverse tumors affords a valuable window into clonal evolution, metastasis, and alterations underlying treatment. Moreover, such an autopsy program yields robust preclinical models of disease.