RESUMO
The accumulation of somatic mutations in healthy human tissues has been extensively characterized, but the mutational landscape of the healthy breast is still poorly understood. Our analysis of whole-genome sequencing shows that in line with other healthy organs, the healthy breast during the reproduction years accumulates mutations with age, with the rate of accumulation in the epithelium of 15.24 ± 5 mutations/year. Both epithelial and stromal compartments contain mutations in breast-specific driver genes, indicative of subsequent positive selection. Parity- and age-associated differences are evident in the mammary epithelium, partly explaining the observed difference in breast cancer risk amongst women of different childbearing age. Parity is associated with an age-dependent increase in the clone size of mutated epithelial cells, suggesting that older first-time mothers have a higher probability of accumulating oncogenic events in the epithelium compared to younger mothers or nulliparous women. In conclusion, we describe the reference genome of the healthy female human breast during reproductive years and provide evidence of how parity affects the genomic landscape of the mammary gland.
Assuntos
Neoplasias da Mama , Mama , Gravidez , Humanos , Feminino , Adulto , Paridade , Neoplasias da Mama/genética , Mutação , Células EpiteliaisRESUMO
CONTEXT: Bladder cancer (BLCA) is a highly prevalent tumour and a health problem worldwide, especially among men. Recent work has highlighted the relevance of the tumour microenvironment (TME) in cancer biology with translational implications. Cancer-associated fibroblasts (CAFs) are a prominent, heterogeneous population of cells in the TME. CAFs have been associated with tumour development, progression, and poor prognosis in several neoplasms. However, their role in BLCA has not yet been exploited deeply. OBJECTIVE: To review the role of CAFs in BLCA biology and provide an understanding of CAF origin, subtypes, markers, and phenotypic and functional characteristics to improve patient management. EVIDENCE ACQUISITION: A PubMed search was performed to review manuscripts published using the terms "cancer associated fibroblast" and "bladder cancer" or "urothelial cancer". All abstracts were reviewed, and the full content of all relevant manuscripts was analysed. In addition, selected manuscripts on CAFs in other tumours were considered. EVIDENCE SYNTHESIS: CAFs have been studied less extensively in BLCA than in other tumours. Thanks to new techniques, such as single-cell RNA-seq and spatial transcriptomics, it is now possible to accurately map and molecularly define the phenotype of fibroblasts in normal bladder and BLCA. Bulk transcriptomic analyses have revealed the existence of subtypes among both non-muscle-invasive and muscle-invasive BLCA; these subtypes display distinct features regarding their CAF content. We provide a higher-resolution map of the phenotypic diversity of CAFs in these tumour subtypes. Preclinical studies and recent promising clinical trials leverage on this knowledge through the combined targeting of CAFs or their effectors and the immune microenvironment. CONCLUSIONS: Current knowledge of BLCA CAFs and the TME is being increasingly applied to improve BLCA therapy. There is a need to acquire a deeper understanding of CAF biology in BLCA. PATIENT SUMMARY: Tumour cells are surrounded by nontumoural cells that contribute to the determination of the behaviour of cancers. Among them are cancer-associated fibroblasts. The "neighbourhoods" established through these cellular interactions can now be studied with much greater resolution. Understanding these features of tumours will contribute to the designing of more effective therapies, especially in relationship to bladder cancer immunotherapy.
Assuntos
Fibroblastos Associados a Câncer , Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Masculino , Bexiga Urinária , Neoplasias da Bexiga Urinária/terapia , Biologia , Microambiente TumoralRESUMO
Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive disease characterized by its metastatic potential and chemoresistance. These traits are partially attributable to the highly tumorigenic pancreatic cancer stem cells (PaCSCs). Interestingly, these cells show unique features in order to sustain their identity and functionality, some of them amenable for therapeutic intervention. Screening of phospho-receptor tyrosine kinases revealed that PaCSCs harbored increased activation of anaplastic lymphoma kinase (ALK). We subsequently demonstrated that oncogenic ALK signaling contributes to tumorigenicity in PDAC patient-derived xenografts (PDXs) by promoting stemness through ligand-dependent activation. Indeed, the ALK ligands midkine (MDK) or pleiotrophin (PTN) increased self-renewal, clonogenicity and CSC frequency in several in vitro local and metastatic PDX models. Conversely, treatment with the clinically-approved ALK inhibitors Crizotinib and Ensartinib decreased PaCSC content and functionality in vitro and in vivo, by inducing cell death. Strikingly, ALK inhibitors sensitized chemoresistant PaCSCs to Gemcitabine, as the most used chemotherapeutic agent for PDAC treatment. Consequently, ALK inhibition delayed tumor relapse after chemotherapy in vivo by effectively decreasing the content of PaCSCs. In summary, our results demonstrate that targeting the MDK/PTN-ALK axis with clinically-approved inhibitors impairs in vivo tumorigenicity and chemoresistance in PDAC suggesting a new treatment approach to improve the long-term survival of PDAC patients.
Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Quinase do Linfoma Anaplásico , Resistencia a Medicamentos Antineoplásicos , Recidiva Local de Neoplasia , Receptores Proteína Tirosina Quinases , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Linhagem Celular Tumoral , Neoplasias PancreáticasRESUMO
OBJECTIVE: GATA6 is a key regulator of the classical phenotype in pancreatic ductal adenocarcinoma (PDAC). Low GATA6 expression associates with poor patient outcome. GATA4 is the second most expressed GATA factor in the pancreas. We assessed whether, and how, GATA4 contributes to PDAC phenotype and analysed the association of expression with outcome and response to chemotherapy. DESIGN: We analysed PDAC transcriptomic data, stratifying cases according to GATA4 and GATA6 expression and identified differentially expressed genes and pathways. The genome-wide distribution of GATA4 was assessed, as well as the effects of GATA4 knockdown. A multicentre tissue microarray study to assess GATA4 and GATA6 expression in samples (n=745) from patients with resectable was performed. GATA4 and GATA6 levels were dichotomised into high/low categorical variables; association with outcome was assessed using univariable and multivariable Cox regression models. RESULTS: GATA4 messenger RNA is enriched in classical, compared with basal-like tumours. We classified samples in 4 groups as high/low for GATA4 and GATA6. Reduced expression of GATA4 had a minor transcriptional impact but low expression of GATA4 enhanced the effects of GATA6 low expression. GATA4 and GATA6 display a partially overlapping genome-wide distribution, mainly at promoters. Reduced expression of both proteins in tumours was associated with the worst patient survival. GATA4 and GATA6 expression significantly decreased in metastases and negatively correlated with basal markers. CONCLUSIONS: GATA4 and GATA6 cooperate to maintain the classical phenotype. Our findings provide compelling rationale to assess their expression as biomarkers of poor prognosis and therapeutic response.
Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/patologia , Pâncreas/patologia , Carcinoma Ductal Pancreático/patologia , Perfilação da Expressão Gênica , Fator de Transcrição GATA6/genética , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismoRESUMO
BACKGROUND & AIMS: The existence of different subtypes of pancreatic ductal adenocarcinoma (PDAC) and their correlation with patient outcome have shifted the emphasis on patient classification for better decision-making algorithms and personalized therapy. The contribution of mechanisms regulating the cancer stem cell (CSC) population in different subtypes remains unknown. METHODS: Using RNA-seq, we identified B-cell CLL/lymphoma 3 (BCL3), an atypical nf-κb signaling member, as differing in pancreatic CSCs. To determine the biological consequences of BCL3 silencing in vivo and in vitro, we generated bcl3-deficient preclinical mouse models as well as murine cell lines and correlated our findings with human cell lines, PDX models, and 2 independent patient cohorts. We assessed the correlation of bcl3 expression pattern with clinical parameters and subtypes. RESULTS: Bcl3 was significantly down-regulated in human CSCs. Recapitulating this phenotype in preclinical mouse models of PDAC via BCL3 genetic knockout enhanced tumor burden, metastasis, epithelial to mesenchymal transition, and reduced overall survival. Fluorescence-activated cell sorting analyses, together with oxygen consumption, sphere formation, and tumorigenicity assays, all indicated that BCL3 loss resulted in CSC compartment expansion promoting cellular dedifferentiation. Overexpression of BCL3 in human PDXs diminished tumor growth by significantly reducing the CSC population and promoting differentiation. Human PDACs with low BCL3 expression correlated with increased metastasis, and BCL3-negative tumors correlated with lower survival and nonclassical subtypes. CONCLUSIONS: We demonstrate that bcl3 impacts pancreatic carcinogenesis by restraining CSC expansion and by curtailing an aggressive and metastatic tumor burden in PDAC across species. Levels of BCL3 expression are a useful stratification marker for predicting subtype characterization in PDAC, thereby allowing for personalized therapeutic approaches.
Assuntos
Proteína 3 do Linfoma de Células B/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Proteína 3 do Linfoma de Células B/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/secundário , Diferenciação Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Metabolismo Energético , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Invasividade Neoplásica , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Transdução de Sinais , Carga Tumoral , Células Tumorais CultivadasRESUMO
OBJECTIVE: To discover serum-based microRNA (miRNA) biomarkers for small-bowel neuroendocrine tumors (SBNET) to help guide clinical decisions. BACKGROUND: MiRNAs are small noncoding RNA molecules implicated in the initiation and progression of many cancers. MiRNAs are remarkably stable in bodily fluids, and can potentially be translated into clinically useful biomarkers. Novel biomarkers are needed in SBNET to determine disease aggressiveness, select patients for treatment, detect early recurrence, and monitor response. METHODS: This study was performed in 3 stages (discovery, validation, and a prospective, longitudinal assessment). Discovery comprised of global profiling of 376 miRNA in sera from SBNET patients (n = 11) versus healthy controls (HCs; n = 3). Up-regulated miRNAs were subsequently validated in additional SBNET (n = 33) and HC sera (n = 14); and then longitudinally after SBNET resection (n = 12), with serial serum sampling (preoperatively day 0; postoperatively at 1 week, 1 month, and 12 months). RESULTS: Four serum miRNAs (miR-125b-5p, -362-5p, -425-5p and -500a-5p) were significantly up-regulated in SBNET (P < 0.05; fold-change >2) based on multiple normalization strategies, and were validated by RT-qPCR. This combination was able to differentiate SBNET from HC with an area under the curve of 0.951. Longitudinal assessment revealed that miR-125b-5p returned towards HC levels at 1 month postoperatively in patients without disease, whereas remaining up-regulated in those with residual disease (RSD). This was also true at 12 months postoperatively. In addition, miR-362-5p appeared up-regulated at 12 months in RSD and recurrent disease (RCD). CONCLUSIONS: Our study represents the largest global profiling of serum miRNAs in SBNET patients, and the first to evaluate ongoing serum miRNA expression changes after surgical resection. Serum miR-125b-5p and miR-362-5p have potential to be used to detect RSD/RCD.
Assuntos
Biomarcadores Tumorais/sangue , MicroRNA Circulante/sangue , Neoplasias Intestinais/diagnóstico , Tumores Neuroendócrinos/diagnóstico , Adulto , Idoso , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Feminino , Humanos , Neoplasias Intestinais/sangue , Neoplasias Intestinais/genética , Neoplasias Intestinais/cirurgia , Intestino Delgado , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/cirurgia , Projetos Piloto , Estudos Prospectivos , Curva ROC , Resultado do Tratamento , Regulação para CimaRESUMO
In many tumors, cells transition reversibly between slow-proliferating tumor-initiating cells (TIC) and their differentiated, faster-growing progeny. Yet, how transcriptional regulation of cell-cycle and self-renewal genes is orchestrated during these conversions remains unclear. In this study, we show that as breast TIC form, a decrease in cell-cycle gene expression and increase in self-renewal gene expression are coregulated by SOX2 and EZH2, which colocalize at CpG islands. This pattern was negatively controlled by a novel long noncoding RNA (lncRNA) that we named Stem Cell Inhibitory RNA Transcript (SCIRT), which was markedly upregulated in tumorspheres but colocalized with and counteracted EZH2 and SOX2 during cell-cycle and self-renewal regulation to restrain tumorigenesis. SCIRT specifically interacted with EZH2 to increase EZH2 affinity to FOXM1 without binding the latter. In this manner, SCIRT induced transcription at cell-cycle gene promoters by recruiting FOXM1 through EZH2 to antagonize EZH2-mediated effects at target genes. Conversely, on stemness genes, FOXM1 was absent and SCIRT antagonized EZH2 and SOX2 activity, balancing toward repression. These data suggest that the interaction of an lncRNA with EZH2 can alter the affinity of EZH2 for its protein-binding partners to regulate cancer cell state transitions. SIGNIFICANCE: These findings show that a novel lncRNA SCIRT counteracts breast tumorigenesis by opposing transcriptional networks associated with cell cycle and self-renewal.See related commentary by Pardini and Dragomir, p. 535.
Assuntos
Neoplasias da Mama , RNA Longo não Codificante , Neoplasias da Mama/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , RNA Longo não Codificante/genéticaRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
TGF-ß/Activin induces epithelial-to-mesenchymal transition and stemness in pancreatic ductal adenocarcinoma (PDAC). However, the microRNAs (miRNAs) regulated during this response have remained yet undetermined. Here, we show that TGF-ß transcriptionally induces MIR100HG lncRNA, containing miR-100, miR-125b and let-7a in its intron, via SMAD2/3. Interestingly, we find that although the pro-tumourigenic miR-100 and miR-125b accordingly increase, the amount of anti-tumourigenic let-7a is unchanged, as TGF-ß also induces LIN28B inhibiting its maturation. Notably, we demonstrate that inactivation of miR-125b or miR-100 affects the TGF-ß-mediated response indicating that these miRNAs are important TGF-ß effectors. We integrate AGO2-RIP-seq with RNA-seq to identify the global regulation exerted by these miRNAs in PDAC cells. Transcripts targeted by miR-125b and miR-100 significantly overlap and mainly inhibit p53 and cell-cell junctions' pathways. Together, we uncover that TGF-ß induces an lncRNA, whose encoded miRNAs, miR-100, let-7a and miR-125b play opposing roles in controlling PDAC tumourigenesis.
Assuntos
Carcinoma Ductal Pancreático/genética , MicroRNAs/genética , Neoplasias Pancreáticas/genética , Proteínas de Ligação a RNA/genética , Fator de Crescimento Transformador beta1/metabolismo , Animais , Carcinogênese/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Conjuntos de Dados como Assunto , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Íntrons/genética , Camundongos , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/metabolismo , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais/genética , Regulação para Cima , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Pancreatic ductal adenocarcinoma (PDAC) and other carcinomas are hierarchically organized, with cancer stem cells (CSC) residing at the top of the hierarchy, where they drive tumor progression, metastasis, and chemoresistance. As CSC and non-CSC share an identical genetic background, we hypothesize that differences in epigenetics account for the striking functional differences between these two cell populations. Epigenetic mechanisms, such as DNA methylation, play an important role in maintaining pluripotency and regulating the differentiation of stem cells, but the role of DNA methylation in pancreatic CSC is obscure. In this study, we investigated the genome-wide DNA methylation profile of PDAC CSC, and we determined the importance of DNA methyltransferases for CSC maintenance and tumorigenicity. Using high-throughput methylation analysis, we discovered that sorted CSCs have a higher level of DNA methylation, regardless of the heterogeneity or polyclonality of the CSC populations present in the tumors analyzed. Mechanistically, CSC expressed higher DNMT1 levels than non-CSC. Pharmacologic or genetic targeting of DNMT1 in CSCs reduced their self-renewal and in vivo tumorigenic potential, defining DNMT1 as a candidate CSC therapeutic target. The inhibitory effect we observed was mediated in part through epigenetic reactivation of previously silenced miRNAs, in particular the miR-17-92 cluster. Together, our findings indicate that DNA methylation plays an important role in CSC biology and also provide a rationale to develop epigenetic modulators to target CSC plasticity and improve the poor outcome of PDAC patients. Cancer Res; 76(15); 4546-58. ©2016 AACR.
Assuntos
Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , DNA (Citosina-5-)-Metiltransferases/genética , MicroRNAs/genética , Células-Tronco Neoplásicas/metabolismo , Adenocarcinoma/patologia , Carcinoma Ductal Pancreático/patologia , Humanos , Células-Tronco Neoplásicas/patologia , RNA Longo não Codificante , Regulação para CimaRESUMO
Cancer stem cells (CSCs) are thought to drive tumor growth, metastasis and chemoresistance. Although surface markers such as CD133 and CD44 have been successfully used to isolate CSCs, their expression is not exclusively linked to the CSC phenotype and is prone to environmental alteration. We identified cells with an autofluorescent subcellular compartment that exclusively showed CSC features across different human tumor types. Primary tumor-derived autofluorescent cells did not overlap with side-population (SP) cells, were enriched in sphere culture and during chemotherapy, strongly expressed pluripotency-associated genes, were highly metastatic and showed long-term in vivo tumorigenicity, even at the single-cell level. Autofluorescence was due to riboflavin accumulation in membrane-bounded cytoplasmic structures bearing ATP-dependent ABCG2 transporters. In summary, we identified and characterized an intrinsic autofluorescent phenotype in CSCs of diverse epithelial cancers and used this marker to isolate and characterize these cells.
Assuntos
Biomarcadores Tumorais/metabolismo , Separação Celular/métodos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Imagem Óptica/métodos , Riboflavina/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Autofagia , Proteína 12 Relacionada à Autofagia , Carcinoma Hepatocelular/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Ductal Pancreático/patologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/biossíntese , Células Tumorais CultivadasRESUMO
Nodal and Activin belong to the TGF-ß superfamily and are important regulators of embryonic stem cell fate. Here we investigated whether Nodal and Activin regulate self-renewal of pancreatic cancer stem cells. Nodal and Activin were hardly detectable in more differentiated pancreatic cancer cells, while cancer stem cells and stroma-derived pancreatic stellate cells markedly overexpressed Nodal and Activin, but not TGF-ß. Knockdown or pharmacological inhibition of the Nodal/Activin receptor Alk4/7 in cancer stem cells virtually abrogated their self-renewal capacity and in vivo tumorigenicity, and reversed the resistance of orthotopically engrafted cancer stem cells to gemcitabine. However, engrafted primary human pancreatic cancer tissue with a substantial stroma showed no response due to limited drug delivery. The addition of a stroma-targeting hedgehog pathway inhibitor enhanced delivery of the Nodal/Activin inhibitor and translated into long-term, progression-free survival. Therefore, inhibition of the Alk4/7 pathway, if combined with hedgehog pathway inhibition and gemcitabine, provides a therapeutic strategy for targeting cancer stem cells.
Assuntos
Ativinas/metabolismo , Transformação Celular Neoplásica/patologia , Células-Tronco Neoplásicas/patologia , Proteína Nodal/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Transdução de Sinais , Antígeno AC133 , Animais , Antígenos CD/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Feminino , Marcação de Genes , Glicoproteínas/metabolismo , Humanos , Camundongos , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/metabolismo , Peptídeos/metabolismo , Células-Tronco Pluripotentes/metabolismo , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: Several studies have suggested that the metabolism of alcohol is modulated by the polymorphisms in genes encoding ethanol-metabolizing enzymes, including alcohol dehydrogenase 1C, ADH1C, and cytochrome P450-dependent monooxygenase, CYP2E1. Genetic polymorphisms of ethanol-metabolizing enzymes may affect individual susceptibility to oral cancer. The purpose of this study was to investigate the associations between ADH1C and CYP2E1 gene polymorphisms with oral squamous cell carcinoma in an ethnically homogeneous Caucasian population. DESIGN: Case-control study. SETTING: Serbian national general hospital. SUBJECTS AND METHODS: The study was conducted on 123 oral cancer patients and a control group of 177 individuals of the Caucasian race and the same ethnicity, matched in age and gender, without previous cancer history. The control group consisted of 120 population-based and 57 hospital-based controls of heavy-drinking individuals. Genetic polymorphisms of ADH1C SspI, ADH1C HaeIII, CYP2E1 RsaI, and CYP2E1 Ins were determined by the polymerase chain reaction and restriction fragment length polymorphisms. RESULTS: After adjustment by potential confounders, the significant increase of oral cancer risk, independent of alcohol drinking, was observed in individuals with the variant ADH1C SspI*2/*2 genotype (odds ratio, 3.029; P = .014) and in combined ADH1C SspI*1/*2 and ADH1C SspI*2/*2 genotypes (odds ratio, 2.605; P = .002), compared to the ADH1C*1/1* wild type. The association of other polymorphisms under study was not observed. CONCLUSION: This study suggested that the ADH1C SspI polymorphism could play a significant role in the etiology of oral cancer, whereas ADH1C HaeIII, CYP2E1 RsaI, and CYP2E1 Ins could have minor influence.