RESUMO
BACKGROUND: The aim of this study was to analyse transcriptomic differences between primary and recurrent high-grade serous ovarian carcinoma (HGSOC) to identify prognostic biomarkers. METHODS: We analysed 19 paired primary and recurrent HGSOC samples using targeted RNA sequencing. We selected the best candidates using in silico survival and pathway analysis and validated the biomarkers using immunohistochemistry on a cohort of 44 paired samples, an additional cohort of 504 primary HGSOCs and explored their function. RESULTS: We identified 233 differential expressed genes. Twenty-three showed a significant prognostic value for PFS and OS in silico. Seven markers (AHRR, COL5A2, FABP4, HMGCS2, ITGA5, SFRP2 and WNT9B) were chosen for validation at the protein level. AHRR expression was higher in primary tumours (p < 0.0001) and correlated with better patient survival (p < 0.05). Stromal SFRP2 expression was higher in recurrent samples (p = 0.009) and protein expression in primary tumours was associated with worse patient survival (p = 0.022). In multivariate analysis, tumour AHRR and SFRP2 remained independent prognostic markers. In vitro studies supported the anti-tumorigenic role of AHRR and the oncogenic function of SFRP2. CONCLUSIONS: Our results underline the relevance of AHRR and SFRP2 proteins in aryl-hydrocarbon receptor and Wnt-signalling, respectively, and might lead to establishing them as biomarkers in HGSOC.
Assuntos
Cistadenocarcinoma Seroso , Neoplasias Ovarianas , Feminino , Humanos , Prognóstico , Neoplasias Ovarianas/patologia , Perfilação da Expressão Gênica , Biomarcadores Tumorais/genética , Cistadenocarcinoma Seroso/patologia , Proteínas de Membrana/genética , Proteínas Repressoras/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genéticaRESUMO
BACKGROUND: Pancreatic neuroendocrine neoplasms (PanNENs) fall into two subclasses: the well-differentiated, low- to high-grade pancreatic neuroendocrine tumors (PanNETs), and the poorly-differentiated, high-grade pancreatic neuroendocrine carcinomas (PanNECs). While recent studies suggest an endocrine descent of PanNETs, the origin of PanNECs remains unknown. METHODS: We performed DNA methylation analysis for 57 PanNEN samples and found that distinct methylation profiles separated PanNENs into two major groups, clearly distinguishing high-grade PanNECs from other PanNETs including high-grade NETG3. DNA alterations and immunohistochemistry of cell-type markers PDX1, ARX, and SOX9 were utilized to further characterize PanNECs and their cell of origin in the pancreas. RESULTS: Phylo-epigenetic and cell-type signature features derived from alpha, beta, acinar, and ductal adult cells suggest an exocrine cell of origin for PanNECs, thus separating them in cell lineage from other PanNENs of endocrine origin. CONCLUSIONS: Our study provides a robust and clinically applicable method to clearly distinguish PanNECs from G3 PanNETs, improving patient stratification.
Assuntos
Carcinoma Neuroendócrino , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Adulto , Carcinoma Neuroendócrino/genética , Carcinoma Neuroendócrino/patologia , Metilação de DNA , Humanos , Gradação de Tumores , Tumores Neuroendócrinos/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologiaRESUMO
Oncoproteins such as the BRAFV600E kinase endow cancer cells with malignant properties, but they also create unique vulnerabilities. Targeting of BRAFV600E-driven cytoplasmic signaling networks has proved ineffective, as patients regularly relapse with reactivation of the targeted pathways. We identify the nuclear protein SFPQ to be synthetically lethal with BRAFV600E in a loss-of-function shRNA screen. SFPQ depletion decreases proliferation and specifically induces S-phase arrest and apoptosis in BRAFV600E-driven colorectal and melanoma cells. Mechanistically, SFPQ loss in BRAF-mutant cancer cells triggers the Chk1-dependent replication checkpoint, results in decreased numbers and reduced activities of replication factories, and increases collision between replication and transcription. We find that BRAFV600E-mutant cancer cells and organoids are sensitive to combinations of Chk1 inhibitors and chemically induced replication stress, pointing toward future therapeutic approaches exploiting nuclear vulnerabilities induced by BRAFV600E.
Assuntos
Neoplasias Colorretais/genética , Mutação/genética , Fator de Processamento Associado a PTB/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Mutações Sintéticas Letais/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem/metabolismo , Neoplasias Colorretais/patologia , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Replicação do DNA/efeitos dos fármacos , Replicação do DNA/genética , Feminino , Humanos , Hidroxiureia/farmacologia , Camundongos Nus , Rad51 Recombinase/metabolismo , Reprodutibilidade dos Testes , Fase S/efeitos dos fármacos , Fase S/genética , Estresse Fisiológico/efeitos dos fármacos , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Colorectal cancer (CRC) development is generally accepted as a sequential process, with genetic mutations determining phenotypic tumor progression. However, matching genetic profiles with histological transition requires the analyses of temporal samples from the same patient at key stages of progression. RESULTS: Here, we compared the genetic profiles of 34 early carcinomas with their respective adenomatous precursors to assess timing and heterogeneity of driver alterations accompanying the switch from benign adenoma to malignant carcinoma. In almost half of the cases, driver mutations specific to the carcinoma stage were not observed. In samples where carcinoma-specific alterations were present, TP53 mutations and chromosome 20 copy gains commonly accompanied the switch from adenomatous tissue to carcinoma. Remarkably, 40% and 50% of high-grade adenomas shared TP53 mutations and chromosome 20 gains, respectively, with their matched carcinomas. In addition, multi-regional analyses revealed greater heterogeneity of driver mutations in adenomas compared to their matched carcinomas. CONCLUSION: Genetic alterations in TP53 and chromosome 20 occur at the earliest histological stage in colorectal carcinomas (pTis and pT1). However, high-grade adenomas can share these alterations despite their histological distinction. Based on the well-defined sequence of CRC development, we suggest that the timing of genetic changes during neoplastic progression is frequently uncoupled from histological progression.
