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1.
Cell ; 158(5): 1094-1109, 2014 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-25171410

RESUMEN

It is increasingly appreciated that oncogenic transformation alters cellular metabolism to facilitate cell proliferation, but less is known about the metabolic changes that promote cancer cell aggressiveness. Here, we analyzed metabolic gene expression in cancer cell lines and found that a set of high-grade carcinoma lines expressing mesenchymal markers share a unique 44 gene signature, designated the "mesenchymal metabolic signature" (MMS). A FACS-based shRNA screen identified several MMS genes as essential for the epithelial-mesenchymal transition (EMT), but not for cell proliferation. Dihydropyrimidine dehydrogenase (DPYD), a pyrimidine-degrading enzyme, was highly expressed upon EMT induction and was necessary for cells to acquire mesenchymal characteristics in vitro and for tumorigenic cells to extravasate into the mouse lung. This role of DPYD was mediated through its catalytic activity and enzymatic products, the dihydropyrimidines. Thus, we identify metabolic processes essential for the EMT, a program associated with the acquisition of metastatic and aggressive cancer cell traits.


Asunto(s)
Transición Epitelial-Mesenquimal , Pirimidinas/metabolismo , Animales , Carcinoma/metabolismo , Línea Celular Tumoral , Dihidrouracilo Deshidrogenasa (NADP)/genética , Citometría de Flujo , Perfilación de la Expresión Génica , Humanos , Mesodermo/citología , Mesodermo/metabolismo , Ratones , ARN Interferente Pequeño/metabolismo
2.
Cell ; 148(5): 1015-28, 2012 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-22385965

RESUMEN

Regulatory networks orchestrated by key transcription factors (TFs) have been proposed to play a central role in the determination of stem cell states. However, the master transcriptional regulators of adult stem cells are poorly understood. We have identified two TFs, Slug and Sox9, that act cooperatively to determine the mammary stem cell (MaSC) state. Inhibition of either Slug or Sox9 blocks MaSC activity in primary mammary epithelial cells. Conversely, transient coexpression of exogenous Slug and Sox9 suffices to convert differentiated luminal cells into MaSCs with long-term mammary gland-reconstituting ability. Slug and Sox9 induce MaSCs by activating distinct autoregulatory gene expression programs. We also show that coexpression of Slug and Sox9 promotes the tumorigenic and metastasis-seeding abilities of human breast cancer cells and is associated with poor patient survival, providing direct evidence that human breast cancer stem cells are controlled by key regulators similar to those operating in normal murine MaSCs.


Asunto(s)
Neoplasias de la Mama/metabolismo , Glándulas Mamarias Humanas/citología , Factor de Transcripción SOX9/metabolismo , Factores de Transcripción/metabolismo , Animales , Células Cultivadas , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Glándulas Mamarias Humanas/metabolismo , Ratones , Factor de Transcripción SOX9/genética , Factores de Transcripción de la Familia Snail , Factores de Transcripción/genética
3.
Proc Natl Acad Sci U S A ; 119(10): e2113233119, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35235448

RESUMEN

SignificanceOur work focuses on the critical longstanding question of the nontranscriptional role of p53 in tumor suppression. We demonstrate here that poly(ADP-ribose) polymerase (PARP)-dependent modification of p53 enables rapid recruitment of p53 to damage sites, where it in turn directs early repair pathway selection. Specifically, p53-mediated recruitment of 53BP1 at early time points promotes nonhomologous end joining over the more error-prone microhomology end-joining. Similarly, p53 directs nucleotide excision repair by mediating DDB1 recruitment. This property of p53 also correlates with tumor suppression in vivo. Our study provides mechanistic insight into how certain transcriptionally deficient p53 mutants may retain tumor-suppressive functions through regulating the DNA damage response.


Asunto(s)
Daño del ADN , Reparación del ADN por Unión de Extremidades , Proteína p53 Supresora de Tumor/metabolismo , Proteína 1 de Unión al Supresor Tumoral P53/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Proteínas de Unión al ADN , Humanos , Mutación , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Dominios Proteicos , Proteína p53 Supresora de Tumor/genética , Proteína 1 de Unión al Supresor Tumoral P53/genética
4.
J Hepatol ; 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38782118

RESUMEN

BACKGROUND & AIMS: Hepatocellular Carcinoma (HCC) is a highly fatal cancer characterized by high intra-tumor heterogeneity (ITH). A panoramic understanding of its tumor evolution, in relation to its clinical trajectory, may provide novel prognostic and treatment strategies. METHODS: Through the Asia-Pacific Hepatocellular Carcinoma (AHCC) trials group (NCT03267641), we recruited one of the largest prospective cohorts of HCC with over 600 whole genome and transcriptome samples from 123 treatment-naïve patients. RESULTS: Using a multi-region sampling approach, we revealed seven convergent genetic evolutionary paths governed by the early driver mutations, late copy number variations and viral integrations, which stratify patient clinical trajectories after surgical resection. Furthermore, such evolutionary paths shaped the molecular profiles, leading to distinct transcriptomic subtypes. Most significantly, although we found the coexistence of multiple transcriptomic subtypes within certain tumors, patient prognosis was best predicted by the most aggressive cell fraction of the tumor, rather than by overall degree of transcriptomic ITH level - a phenomenon we termed the 'bad apple' effect. Finally, we found that characteristics throughout early and late tumor evolution provide significant and complementary prognostic power in predicting patient survival. CONCLUSIONS: Taken together, our study generated a comprehensive landscape of evolutionary history for HCC and provided a rich multi-omics resource for understanding tumor heterogeneity and clinical trajectories. CLINICAL TRIAL NUMBER: NCT03267641 (Observational cohort) IMPACT AND IMPLICATIONS: This prospective study, utilizing comprehensive multi-sector, multi-omics sequencing and clinical data from surgically resected HCC, reveals critical insights into the role of tumor evolution and intra-tumor heterogeneity (ITH) in determining the prognosis of Hepatocellular Carcinoma (HCC). These findings are invaluable for oncology researchers and clinicians, as they underscore the influence of distinct evolutionary paths and the 'bad apple' effect, where the most aggressive tumor fraction dictates disease progression. These insights not only enhance prognostic accuracy post-surgical resection but also pave the way for developing personalized therapies tailored to specific tumor evolutionary and transcriptomic profiles. The co-existence of multiple sub-types within the same tumor prompts a re-appraisal of the utilities of depending on single samples to represent the entire tumor and suggests the need for clinical molecular imaging. This research thus marks a significant step forward in the clinical understanding and management of HCC, underscoring the importance of integrating tumor evolutionary dynamics and multi-omics biomarkers into therapeutic decision-making.

5.
J Pathol ; 259(3): 342-356, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36573560

RESUMEN

The relatively quiet mutational landscape of rhabdomyosarcoma (RMS) suggests that epigenetic deregulation could be central to oncogenesis and tumour aggressiveness. Histone variants have long been recognised as important epigenetic regulators of gene expression. However, the role of histone variants in RMS has not been studied hitherto. In this study, we show that histone variant H3.3 is overexpressed in alveolar RMS (ARMS), an aggressive subtype of RMS. Functionally, knockdown of H3F3A, which encodes for H3.3, significantly impairs the ability of ARMS cells to undertake migration and invasion and reduces Rho activation. In addition, a striking reduction in metastatic tumour burden and improved survival is apparent in vivo. Using RNA-sequencing and ChIP-sequencing analyses, we identified melanoma cell adhesion molecule (MCAM/CD146) as a direct downstream target of H3.3. Loss of H3.3 resulted in a reduction in the presence of active marks and an increase in the occupancy of H1 at the MCAM promoter. Cell migration and invasion were rescued in H3F3A-depleted cells through MCAM overexpression. Moreover, we identified G9a, a lysine methyltransferase encoded by EHMT2, as an upstream regulator of H3F3A. Therefore, this study identifies a novel H3.3 dependent axis involved in ARMS metastasis. These findings establish the potential of MCAM as a therapeutic target for high-risk ARMS patients. © 2022 The Pathological Society of Great Britain and Ireland.


Asunto(s)
Histonas , Rabdomiosarcoma Alveolar , Humanos , Línea Celular Tumoral , Antígenos de Histocompatibilidad/genética , Antígenos de Histocompatibilidad/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , Histonas/genética , Histonas/metabolismo , Regiones Promotoras Genéticas , Rabdomiosarcoma Alveolar/genética , Rabdomiosarcoma Alveolar/patología
6.
Biochem J ; 480(24): 2045-2058, 2023 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-38078799

RESUMEN

The SLC7A11/xCT cystine and glutamate antiporter has emerged as an attractive target for cancer therapy due to its selective overexpression in multiple cancers and its role in preventing ferroptosis. Utilizing pharmacological and genetic approaches in hepatocellular carcinoma cell lines, we demonstrate that overexpression of SLC7A11 engenders hypersensitivity towards l-selenocystine, a naturally occurring diselenide that bears close structural similarity to l-cystine. We find that the abundance of SLC7A11 positively correlates with sensitivity to l-selenocystine, but surprisingly, not to Erastin, an inhibitor of SLC7A11 activity. Our data indicate that SLC7A11 acts as a transport channel for l-selenocystine, which preferentially incites acute oxidative stress and damage eventuating to cell death in cells that highly express SLC7A11. Hence, our findings raise the prospect of l-selenocystine administration as a novel strategy for targeting cancers that up-regulate SLC7A11 expression.


Asunto(s)
Cistina , Línea Celular Tumoral , Cistina/metabolismo , Regulación hacia Arriba , Sistema de Transporte de Aminoácidos y+/metabolismo
7.
Hepatology ; 76(5): 1329-1344, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35184329

RESUMEN

BACKGROUND AND AIMS: Hypoxia is one of the central players in shaping the immune context of the tumor microenvironment (TME). However, the complex interplay between immune cell infiltrates within the hypoxic TME of HCC remains to be elucidated. APPROACH AND RESULTS: We analyzed the immune landscapes of hypoxia-low and hypoxia-high tumor regions using cytometry by time of light, immunohistochemistry, and transcriptomic analyses. The mechanisms of immunosuppression in immune subsets of interest were further explored using in vitro hypoxia assays. Regulatory T cells (Tregs) and a number of immunosuppressive myeloid subsets, including M2 macrophages and human leukocyte antigen-DR isotype (HLA-DRlo ) type 2 conventional dendritic cell (cDC2), were found to be significantly enriched in hypoxia-high tumor regions. On the other hand, the abundance of active granzyme Bhi PD-1lo CD8+ T cells in hypoxia-low tumor regions implied a relatively active immune landscape compared with hypoxia-high regions. The up-regulation of cancer-associated genes in the tumor tissues and immunosuppressive genes in the tumor-infiltrating leukocytes supported a highly pro-tumorigenic network in hypoxic HCC. Chemokine genes such as CCL20 (C-C motif chemokine ligand 20) and CXCL5 (C-X-C motif chemokine ligand 5) were associated with recruitment of both Tregs and HLA-DRlo cDC2 to hypoxia-high microenvironments. The interaction between Tregs and cDC2 under a hypoxic TME resulted in a loss of antigen-presenting HLA-DR on cDC2. CONCLUSIONS: We uncovered the unique immunosuppressive landscapes and identified key immune subsets enriched in hypoxic HCC. In particular, we identified a potential Treg-mediated immunosuppression through interaction with a cDC2 subset in HCC that could be exploited for immunotherapies.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Linfocitos T Reguladores , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Granzimas/metabolismo , Linfocitos T CD8-positivos , Receptor de Muerte Celular Programada 1/metabolismo , Ligandos , Microambiente Tumoral , Terapia de Inmunosupresión , Hipoxia/metabolismo , Células Dendríticas/metabolismo , Antígenos HLA
8.
Stem Cells ; 40(1): 112-122, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-35511868

RESUMEN

Mammary gland homeostasis is maintained by adult tissue stem-progenitor cells residing within the luminal and basal epithelia. Dysregulation of mammary stem cells is a key mechanism for cancer development. However, stem cell characterization is challenging because reporter models using cell-specific promoters do not fully recapitulate the mammary stem cell populations. We previously found that a 270-basepair Runx1 enhancer element, named eR1, marked stem cells in the blood and stomach. Here, we identified eR1 activity in a rare subpopulation of the ERα-negative luminal epithelium in mouse mammary glands. Lineage-tracing using an eR1-CreERT2 mouse model revealed that eR1+ luminal cells generated the entire luminal lineage and milk-secreting alveoli-eR1 therefore specifically marks lineage-restricted luminal stem cells. eR1-targeted-conditional knockout of Runx1 led to the expansion of luminal epithelial cells, accompanied by elevated ERα expression. Our findings demonstrate a definitive role for Runx1 in the regulation of the eR1-positive luminal stem cell proliferation during mammary homeostasis. Our findings identify a mechanistic link for Runx1 in stem cell proliferation and its dysregulation in breast cancer. Runx1 inactivation is therefore likely to be an early hit in the cell-of-origin of ERα+ luminal type breast cancer.


Asunto(s)
Receptor alfa de Estrógeno , Glándulas Mamarias Animales , Animales , Linaje de la Célula , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Elementos de Facilitación Genéticos/genética , Células Epiteliales/metabolismo , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Ratones , Células Madre/metabolismo
9.
Mol Psychiatry ; 27(11): 4510-4525, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36056172

RESUMEN

Depression and anxiety are major global health burdens. Although SSRIs targeting the serotonergic system are prescribed over 200 million times annually, they have variable therapeutic efficacy and side effects, and mechanisms of action remain incompletely understood. Here, we comprehensively characterise the molecular landscape of gene regulatory changes associated with fluoxetine, a widely-used SSRI. We performed multimodal analysis of SSRI response in 27 mammalian brain regions using 310 bulk RNA-seq and H3K27ac ChIP-seq datasets, followed by in-depth characterisation of two hippocampal regions using single-cell RNA-seq (20 datasets). Remarkably, fluoxetine induced profound region-specific shifts in gene expression and chromatin state, including in the nucleus accumbens shell, locus coeruleus and septal areas, as well as in more well-studied regions such as the raphe and hippocampal dentate gyrus. Expression changes were strongly enriched at GWAS loci for depression and antidepressant drug response, stressing the relevance to human phenotypes. We observed differential expression at dozens of signalling receptors and pathways, many of which are previously unknown. Single-cell analysis revealed stark differences in fluoxetine response between the dorsal and ventral hippocampal dentate gyri, particularly in oligodendrocytes, mossy cells and inhibitory neurons. Across diverse brain regions, integrative omics analysis consistently suggested increased energy metabolism via oxidative phosphorylation and mitochondrial changes, which we corroborated in vitro; this may thus constitute a shared mechanism of action of fluoxetine. Similarly, we observed pervasive chromatin remodelling signatures across the brain. Our study reveals unexpected regional and cell type-specific heterogeneity in SSRI action, highlights under-studied brain regions that may play a major role in antidepressant response, and provides a rich resource of candidate cell types, genes, gene regulatory elements and pathways for mechanistic analysis and identifying new therapeutic targets for depression and anxiety.


Asunto(s)
Ensamble y Desensamble de Cromatina , Fluoxetina , Humanos , Antidepresivos/farmacología , Encéfalo/metabolismo , Metabolismo Energético/genética , Fluoxetina/farmacología , Fluoxetina/metabolismo , Mamíferos , Multiómica , Animales
10.
Nucleic Acids Res ; 49(3): e13, 2021 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-33275158

RESUMEN

Recent advances in single-cell open-chromatin and transcriptome profiling have created a challenge of exploring novel applications with a meaningful transformation of read-counts, which often have high variability in noise and drop-out among cells. Here, we introduce UniPath, for representing single-cells using pathway and gene-set enrichment scores by a transformation of their open-chromatin or gene-expression profiles. The robust statistical approach of UniPath provides high accuracy, consistency and scalability in estimating gene-set enrichment scores for every cell. Its framework provides an easy solution for handling variability in drop-out rate, which can sometimes create artefact due to systematic patterns. UniPath provides an alternative approach of dimension reduction of single-cell open-chromatin profiles. UniPath's approach of predicting temporal-order of single-cells using their pathway enrichment scores enables suppression of covariates to achieve correct order of cells. Analysis of mouse cell atlas using our approach yielded surprising, albeit biologically-meaningful co-clustering of cell-types from distant organs. By enabling an unconventional method of exploiting pathway co-occurrence to compare two groups of cells, our approach also proves to be useful in inferring context-specific regulations in cancer cells. Available at https://reggenlab.github.io/UniPathWeb/.


Asunto(s)
Epigenómica/métodos , RNA-Seq/métodos , Análisis de la Célula Individual/métodos , Animales , Línea Celular Tumoral , Cromatina , Análisis por Conglomerados , Epigenoma , Genes , Humanos , Ratones , Neoplasias/genética
11.
Circ Res ; 127(6): 761-777, 2020 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-32529949

RESUMEN

RATIONALE: Identifying genetic markers for heterogeneous complex diseases such as heart failure is challenging and requires prohibitively large cohort sizes in genome-wide association studies to meet the stringent threshold of genome-wide statistical significance. On the other hand, chromatin quantitative trait loci, elucidated by direct epigenetic profiling of specific human tissues, may contribute toward prioritizing subthreshold variants for disease association. OBJECTIVE: Here, we captured noncoding genetic variants by performing epigenetic profiling for enhancer H3K27ac chromatin immunoprecipitation followed by sequencing in 70 human control and end-stage failing hearts. METHODS AND RESULTS: We have mapped a comprehensive catalog of 47 321 putative human heart enhancers and promoters. Three thousand eight hundred ninety-seven differential acetylation peaks (FDR [false discovery rate], 5%) pointed to pathways altered in heart failure. To identify cardiac histone acetylation quantitative trait loci (haQTLs), we regressed out confounding factors including heart failure disease status and used the G-SCI (Genotype-independent Signal Correlation and Imbalance) test1 to call out 1680 haQTLs (FDR, 10%). RNA sequencing performed on the same heart samples proved a subset of haQTLs to have significant association also to gene expression (expression quantitative trait loci), either in cis (180) or through long-range interactions (81), identified by Hi-C (high-throughput chromatin conformation assay) and HiChIP (high-throughput protein centric chromatin) performed on a subset of hearts. Furthermore, a concordant relationship between the gain or disruption of TF (transcription factor)-binding motifs, inferred from alternative alleles at the haQTLs, implied a surprising direct association between these specific TF and local histone acetylation in human hearts. Finally, 62 unique loci were identified by colocalization of haQTLs with the subthreshold loci of heart-related genome-wide association studies datasets. CONCLUSIONS: Disease and phenotype association for 62 unique loci are now implicated. These loci may indeed mediate their effect through modification of enhancer H3K27 acetylation enrichment and their corresponding gene expression differences (bioRxiv: https://doi.org/10.1101/536763). Graphical Abstract: A graphical abstract is available for this article.


Asunto(s)
Epigenoma , Variación Genética , Insuficiencia Cardíaca/genética , Histonas/genética , Acetilación , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Inmunoprecipitación de Cromatina , Bases de Datos Genéticas , Epigénesis Genética , Epigenómica , Femenino , Predisposición Genética a la Enfermedad , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Secuenciación de Nucleótidos de Alto Rendimiento , Histonas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Sitios de Carácter Cuantitativo
12.
Cell Mol Life Sci ; 78(4): 1837-1851, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32851475

RESUMEN

Proteasome inhibitors, such as bortezomib and carfilzomib, have shown efficacy in anti-cancer therapy in hematological diseases but not in solid cancers. Here, we found that liposarcomas (LPS) are susceptible to proteasome inhibition, and identified drugs that synergize with carfilzomib, such as selinexor, an inhibitor of XPO1-mediated nuclear export. Through quantitative nuclear protein profiling and phospho-kinase arrays, we identified potential mode of actions of this combination, including interference with ribosome biogenesis and inhibition of pro-survival kinase PRAS40. Furthermore, by assessing global protein levels changes, FADS2, a key enzyme regulating fatty acids synthesis, was found down-regulated after proteasome inhibition. Interestingly, SC26196, an inhibitor of FADS2, synergized with carfilzomib. Finally, to identify further combinational options, we performed high-throughput drug screening and uncovered novel drug interactions with carfilzomib. For instance, cyclosporin A, a known immunosuppressive agent, enhanced carfilzomib's efficacy in vitro and in vivo. Altogether, these results demonstrate that carfilzomib and its combinations could be repurposed for LPS clinical management.


Asunto(s)
Ácido Graso Desaturasas/genética , Carioferinas/genética , Liposarcoma/tratamiento farmacológico , Oligopéptidos/farmacología , Receptores Citoplasmáticos y Nucleares/genética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Bortezomib/farmacología , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Sinergismo Farmacológico , Ácido Graso Desaturasas/antagonistas & inhibidores , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Hidrazinas/farmacología , Liposarcoma/genética , Liposarcoma/patología , Piperazinas/farmacología , Complejo de la Endopetidasa Proteasomal/efectos de los fármacos , Inhibidores de Proteasoma/farmacología , Triazoles/farmacología , Proteína Exportina 1
13.
Med Res Rev ; 41(6): 2893-2926, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33533067

RESUMEN

Small-molecule drugs modulate biological processes and disease states through engagement of target proteins in cells. Assessing drug-target engagement on a proteome-wide scale is of utmost importance in better understanding the molecular mechanisms of action of observed beneficial and adverse effects, as well as in developing next generation tool compounds and drugs with better efficacies and specificities. However, systematic assessment of drug-target engagement has been an arduous task. With the continuous development of mass spectrometry-based proteomics instruments and techniques, various chemical proteomics approaches for drug target deconvolution (i.e., the identification of molecular target for drugs) have emerged. Among these, the label-free target deconvolution approaches that do not involve the chemical modification of compounds of interest, have gained increased attention in the community. Here we provide an overview of the basic principles and recent biological applications of the most important label-free methods including the cellular thermal shift assay, pulse proteolysis, chemical denaturant and protein precipitation, stability of proteins from rates of oxidation, drug affinity responsive target stability, limited proteolysis, and solvent-induced protein precipitation. The state-of-the-art technical implications and future outlook for the label-free approaches are also discussed.


Asunto(s)
Proteoma , Proteómica , Sistemas de Liberación de Medicamentos , Humanos , Oxidación-Reducción , Proteoma/metabolismo , Proteómica/métodos , Solventes
14.
Nature ; 525(7568): 256-60, 2015 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-26331542

RESUMEN

Tumour-initiating cells (TICs) are responsible for metastatic dissemination and clinical relapse in a variety of cancers. Analogies between TICs and normal tissue stem cells have led to the proposal that activation of the normal stem-cell program within a tissue serves as the major mechanism for generating TICs. Supporting this notion, we and others previously established that the Slug epithelial-to-mesenchymal transition-inducing transcription factor (EMT-TF), a member of the Snail family, serves as a master regulator of the gland-reconstituting activity of normal mammary stem cells, and that forced expression of Slug in collaboration with Sox9 in breast cancer cells can efficiently induce entrance into the TIC state. However, these earlier studies focused on xenograft models with cultured cell lines and involved ectopic expression of EMT-TFs, often at non-physiological levels. Using genetically engineered knock-in reporter mouse lines, here we show that normal gland-reconstituting mammary stem cells residing in the basal layer of the mammary epithelium and breast TICs originating in the luminal layer exploit the paralogous EMT-TFs Slug and Snail, respectively, which induce distinct EMT programs. Broadly, our findings suggest that the seemingly similar stem-cell programs operating in TICs and normal stem cells of the corresponding normal tissue are likely to differ significantly in their details.


Asunto(s)
Transición Epitelial-Mesenquimal/fisiología , Glándulas Mamarias Animales/citología , Células Madre Neoplásicas/citología , Células Madre/citología , Animales , Transición Epitelial-Mesenquimal/genética , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Ratones , Células Madre Neoplásicas/metabolismo , Factor de Transcripción SOX9/metabolismo , Factores de Transcripción de la Familia Snail , Células Madre/metabolismo , Factores de Transcripción/deficiencia , Factores de Transcripción/metabolismo
15.
Gastroenterology ; 157(6): 1615-1629.e17, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31446059

RESUMEN

BACKGROUND & AIMS: Some oncogenes encode transcription factors, but few drugs have been successfully developed to block their activity specifically in cancer cells. The transcription factor SALL4 is aberrantly expressed in solid tumor and leukemia cells. We developed a screen to identify compounds that reduce the viability of liver cancer cells that express high levels of SALL4, and we investigated their mechanisms. METHODS: We developed a stringent high-throughput screening platform comprising unmodified SNU-387 and SNU-398 liver cancer cell lines and SNU-387 cell lines engineered to express low and high levels of SALL4. We screened 1597 pharmacologically active small molecules and 21,575 natural product extracts from plant, bacteria, and fungal sources for those that selectively reduce the viability of cells with high levels of SALL4 (SALL4hi cells). We compared gene expression patterns of SALL4hi cells vs SALL4-knockdown cells using RNA sequencing and real-time polymerase chain reaction analyses. Xenograft tumors were grown in NOD/SCID gamma mice from SALL4hi SNU-398 or HCC26.1 cells or from SALL4lo patient-derived xenograft (PDX) cells; mice were given injections of identified compounds or sorafenib, and the effects on tumor growth were measured. RESULTS: Our screening identified 1 small molecule (PI-103) and 4 natural compound analogues (oligomycin, efrapeptin, antimycin, and leucinostatin) that selectively reduced viability of SALL4hi cells. We performed validation studies, and 4 of these compounds were found to inhibit oxidative phosphorylation. The adenosine triphosphate (ATP) synthase inhibitor oligomycin reduced the viability of SALL4hi hepatocellular carcinoma and non-small-cell lung cancer cell lines with minimal effects on SALL4lo cells. Oligomycin also reduced the growth of xenograft tumors grown from SALL4hi SNU-398 or HCC26.1 cells to a greater extent than sorafenib, but oligomycin had little effect on tumors grown from SALL4lo PDX cells. Oligomycin was not toxic to mice. Analyses of chromatin immunoprecipitation sequencing data showed that SALL4 binds approximately 50% of mitochondrial genes, including many oxidative phosphorylation genes, to activate their transcription. In comparing SALL4hi and SALL4-knockdown cells, we found SALL4 to increase oxidative phosphorylation, oxygen consumption rate, mitochondrial membrane potential, and use of oxidative phosphorylation-related metabolites to generate ATP. CONCLUSIONS: In a screening for compounds that reduce the viability of cells that express high levels of the transcription factor SALL4, we identified inhibitors of oxidative phosphorylation, which slowed the growth of xenograft tumors from SALL4hi cells in mice. SALL4 activates the transcription of genes that regulate oxidative phosphorylation to increase oxygen consumption, mitochondrial membrane potential, and ATP generation in cancer cells. Inhibitors of oxidative phosphorylation might be used for the treatment of liver tumors with high levels of SALL4.


Asunto(s)
Antineoplásicos/farmacología , Ensayos Analíticos de Alto Rendimiento/métodos , Neoplasias Hepáticas/tratamiento farmacológico , Factores de Transcripción/antagonistas & inhibidores , Animales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Masculino , Ratones , Fosforilación Oxidativa/efectos de los fármacos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Nature ; 508(7494): 103-107, 2014 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-24670641

RESUMEN

Cancer cells induce a set of adaptive response pathways to survive in the face of stressors due to inadequate vascularization. One such adaptive pathway is the unfolded protein (UPR) or endoplasmic reticulum (ER) stress response mediated in part by the ER-localized transmembrane sensor IRE1 (ref. 2) and its substrate XBP1 (ref. 3). Previous studies report UPR activation in various human tumours, but the role of XBP1 in cancer progression in mammary epithelial cells is largely unknown. Triple-negative breast cancer (TNBC)--a form of breast cancer in which tumour cells do not express the genes for oestrogen receptor, progesterone receptor and HER2 (also called ERBB2 or NEU)--is a highly aggressive malignancy with limited treatment options. Here we report that XBP1 is activated in TNBC and has a pivotal role in the tumorigenicity and progression of this human breast cancer subtype. In breast cancer cell line models, depletion of XBP1 inhibited tumour growth and tumour relapse and reduced the CD44(high)CD24(low) population. Hypoxia-inducing factor 1α (HIF1α) is known to be hyperactivated in TNBCs. Genome-wide mapping of the XBP1 transcriptional regulatory network revealed that XBP1 drives TNBC tumorigenicity by assembling a transcriptional complex with HIF1α that regulates the expression of HIF1α targets via the recruitment of RNA polymerase II. Analysis of independent cohorts of patients with TNBC revealed a specific XBP1 gene expression signature that was highly correlated with HIF1α and hypoxia-driven signatures and that strongly associated with poor prognosis. Our findings reveal a key function for the XBP1 branch of the UPR in TNBC and indicate that targeting this pathway may offer alternative treatment strategies for this aggressive subtype of breast cancer.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Factores de Transcripción/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Animales , Antígeno CD24/metabolismo , Hipoxia de la Célula/genética , Línea Celular Tumoral , Proliferación Celular , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Progresión de la Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Silenciador del Gen , Humanos , Receptores de Hialuranos/metabolismo , Ratones , Invasividad Neoplásica , Recurrencia Local de Neoplasia , Pronóstico , ARN Polimerasa II/metabolismo , Factores de Transcripción del Factor Regulador X , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Transcripción Genética , Neoplasias de la Mama Triple Negativas/irrigación sanguínea , Neoplasias de la Mama Triple Negativas/genética , Respuesta de Proteína Desplegada , Proteína 1 de Unión a la X-Box
17.
J Am Chem Soc ; 141(37): 14673-14686, 2019 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-31436967

RESUMEN

Tumor initiating cells (TIC) are resistant to conventional anticancer therapy and associated with metastasis and relapse in cancer. Although various TIC markers and their antibodies have been proposed, it is limited to the use of antibodies for in vivo imaging or treatment of TIC. In this study, we discovered heme oxygenase 2 (HMOX2) as a novel biomarker for TIC and developed a selective small molecule probe TiNIR (tumor initiating cell probe with near infrared). TiNIR detects and enriches the functionally active TIC in human lung tumors, and through the photoacoustic property, TiNIR also visualizes lung TIC in the patient-derived xenograft (PDX) model. Furthermore, we demonstrate that TiNIR inhibits tumor growth by blocking the function of HMOX2, resulting in significantly increased survival rates of the cancer model mice. The novel therapeutic target HMOX2 and its fluorescent ligand TiNIR will open a new path for the molecular level of lung TIC diagnosis and treatment.


Asunto(s)
Colorantes Fluorescentes/farmacología , Hemo Oxigenasa (Desciclizante)/metabolismo , Neoplasias Pulmonares/patología , Células Madre Neoplásicas/efectos de los fármacos , Espectroscopía Infrarroja Corta/métodos , Animales , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Ratones , Células Madre Neoplásicas/enzimología , Tasa de Supervivencia , Ensayos Antitumor por Modelo de Xenoinjerto
18.
Neurobiol Dis ; 124: 1-13, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30391288

RESUMEN

Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative disease caused by the expansion of polyglutamine region in the androgen receptor. To gain insights into mechanisms of SBMA, four wild-type and five SBMA iPSC lines were differentiated to spinal motor neurons (sMNs) with high efficiency. SBMA sMNs showed neurite defects, reduced sMN survival and decreased protein synthesis levels. Microarray analysis revealed a dysregulation in various neuronal-related signalling pathways in SBMA sMNs. Strikingly, FAM135B a novel gene of unknown function, was found drastically downregulated in SBMA sMNs. Knockdown of FAM135B in wild-type sMNs reduced their survival and contributed to neurite defects, similar to SBMA sMNs, suggesting a functional role of FAM135B in SBMA. The degenerative phenotypes and dysregulated genes revealed could be potential therapeutic targets for SBMA.


Asunto(s)
Atrofia Bulboespinal Ligada al X/metabolismo , Atrofia Bulboespinal Ligada al X/patología , Péptidos y Proteínas de Señalización Intracelular/fisiología , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Neuritas/metabolismo , Neuritas/patología , Atrofia Bulboespinal Ligada al X/genética , Diferenciación Celular , Perfilación de la Expresión Génica , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Péptidos y Proteínas de Señalización Intracelular/genética , Fenotipo , Transducción de Señal
20.
Angew Chem Int Ed Engl ; 57(11): 2851-2854, 2018 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-29377425

RESUMEN

Tumor initiating cells (TICs) have been implicated in clinical relapse and metastasis of a variety of epithelial cancers, including lung cancer. While efforts toward the development of specific probes for TIC detection and targeting are ongoing, a universal TIC probe has yet to be developed. We report the first TIC-specific fluorescent chemical probe, TiY, with identification of the molecular target as vimentin, a marker for epithelial-to-mesenchymal transition (EMT). TiY selectively stains TICs over differentiated tumor cells or normal cells, and facilitates the visualization and enrichment of functionally active TICs from patient tumors. At high concentration, TiY also shows anti-TIC activity with low toxicity to non-TICs. With the unexplored target vimentin, TiY shows potential as a first universal probe for TIC detection in different cancers.


Asunto(s)
Colorantes Fluorescentes/química , Células Madre Neoplásicas/patología , Bibliotecas de Moléculas Pequeñas/química , Vimentina/análisis , Animales , Biomarcadores de Tumor/análisis , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Transición Epitelial-Mesenquimal , Humanos , Neoplasias Pulmonares/patología , Ratones
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