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1.
Nature ; 612(7939): 347-353, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36385525

RESUMO

Solid cancers exhibit a dynamic balance between cell death and proliferation ensuring continuous tumour maintenance and growth1,2. Increasing evidence links enhanced cancer cell apoptosis to paracrine activation of cells in the tumour microenvironment initiating tissue repair programs that support tumour growth3,4, yet the direct effects of dying cancer cells on neighbouring tumour epithelia and how this paracrine effect potentially contributes to therapy resistance are unclear. Here we demonstrate that chemotherapy-induced tumour cell death in patient-derived colorectal tumour organoids causes ATP release triggering P2X4 (also known as P2RX4) to mediate an mTOR-dependent pro-survival program in neighbouring cancer cells, which renders surviving tumour epithelia sensitive to mTOR inhibition. The induced mTOR addiction in persisting epithelial cells is due to elevated production of reactive oxygen species and subsequent increased DNA damage in response to the death of neighbouring cells. Accordingly, inhibition of the P2X4 receptor or direct mTOR blockade prevents induction of S6 phosphorylation and synergizes with chemotherapy to cause massive cell death induced by reactive oxygen species and marked tumour regression that is not seen when individually applied. Conversely, scavenging of reactive oxygen species prevents cancer cells from becoming reliant on mTOR activation. Collectively, our findings show that dying cancer cells establish a new dependency on anti-apoptotic programs in their surviving neighbours, thereby creating an opportunity for combination therapy in P2X4-expressing epithelial tumours.


Assuntos
Neoplasias do Colo , Organoides , Humanos , Espécies Reativas de Oxigênio , Causas de Morte , Morte Celular , Microambiente Tumoral , Serina-Treonina Quinases TOR
2.
Oncogene ; 38(11): 1787-1801, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30353167

RESUMO

While great advances have been achieved regarding the genetic basis of colorectal cancer, the complex role of cell-cell communication and cytokine-induced signaling during its pathogenesis remains less understood. Signal transducer and activator of transcription 6 (Stat6) is the main transcription factor of interleukin-4 (IL-4) signaling and its participation in the development of various tumor types has been already reported. Here we aimed to examine the contribution of Stat6 in intestinal epithelial cells (IEC) in mouse models of intestinal carcinogenesis. Wild-type (WT), Stat6 knockout (Stat6-/-), and intestinal epithelial cell-specific IL-4Rα knockout (Il-4rαΔIEC) mice were subjected to colitis-associated (AOM/DSS) and colitis-independent (sporadic) carcinogenesis. IEC proliferation, apoptosis and RNA expression were evaluated by immunohistochemical, immunoblot, and RT-PCR analysis. We found that Stat6-/- mice developed more tumors in the colitis-associated carcinogenesis model. This was accompanied by a more pronounced inflammatory response during colitis and an elevated Stat3-dependent proliferation of IEC. Increased sensitivity to DSS-induced colitis was caused by elevated cell death in response to the initial carcinogen exposure as Stat6 deficiency led to increased chromatin compaction affecting DNA damage response in IEC upon treatment with alkylating agents independently of IL-4Rα engagement. Thus, loss of Stat6 caused more severe colitis and increased tumor load, however loss-of-initiated Stat6-/- IEC prevented tumor formation in the absence of overt inflammation. Our data unravel unexpected IL-4-independent functions of Stat6 in chromatin compaction in intestinal epithelial cells ultimately providing both tumor suppressive as well as tumor promoting effects in different models of intestinal tumorigenesis.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Cromatina/metabolismo , Colite/complicações , Neoplasias do Colo , Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Fator de Transcrição STAT6/genética , Animais , Carcinogênese/genética , Carcinogênese/imunologia , Carcinogênese/patologia , Colite/genética , Colite/patologia , Neoplasias do Colo/genética , Neoplasias do Colo/imunologia , Neoplasias do Colo/patologia , Empacotamento do DNA/genética , Modelos Animais de Doenças , Células Epiteliais/patologia , Feminino , Deleção de Genes , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
3.
Cell Death Differ ; 26(11): 2223-2236, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30737477

RESUMO

Cancer cells frequently boost nucleotide metabolism (NM) to support their increased proliferation, but the consequences of elevated NM on tumor de-differentiation are mostly unexplored. Here, we identified a role for thymidylate synthase (TS), a NM enzyme and established drug target, in cancer cell de-differentiation and investigated its clinical significance in breast cancer (BC). In vitro, TS knockdown increased the population of CD24+ differentiated cells, and attenuated migration and sphere-formation. RNA-seq profiling indicated repression of epithelial-to-mesenchymal transition (EMT) signature genes upon TS knockdown, and TS-deficient cells showed an increased ability to invade and metastasize in vivo, consistent with the occurrence of a partial EMT phenotype. Mechanistically, TS enzymatic activity was found essential for maintenance of the EMT/stem-like state by fueling a dihydropyrimidine dehydrogenase-dependent pyrimidine catabolism. In patient tissues, TS levels were found significantly higher in poorly differentiated and in triple negative BC, and strongly correlated with worse prognosis. The present study provides the rationale to study in-depth the role of NM at the crossroads of proliferation and differentiation, and depicts new avenues for the design of novel drug combinations for the treatment of BC.


Assuntos
Desdiferenciação Celular/fisiologia , Timidilato Sintase/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Animais , Antígeno CD24/metabolismo , Movimento Celular , Proliferação de Células/fisiologia , Di-Hidrouracila Desidrogenase (NADP)/metabolismo , Transição Epitelial-Mesenquimal/genética , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica/genética , Prognóstico , Pirimidinas/metabolismo , Esferoides Celulares , Timidilato Sintase/genética , Células Tumorais Cultivadas
4.
Oncogene ; 37(16): 2089-2103, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29379166

RESUMO

Epithelial ovarian carcinoma (EOC) patients often acquire resistance against common chemotherapeutic drugs like paclitaxel and cisplatin. The mechanism responsible for the same is ambiguous. We have identified a putative drug-resistant tumour cell phenotype (EpCAM+CD45+) in the ascitic fluid of EOC patients, which appears to originate from the primary tumour. These cells represent the major tumour burden and are more drug resistant compared to EpCAM+ tumour cells due to the over-expression of SIRT1, ABCA1 and BCL2 genes. We have found that the entire EpCAM+CD45+ population is highly invasive with signature mesenchymal gene expression and also consists of subpopulations of ovarian cancer stem cells (CD133+ and CD117+CD44+). Additionally, we demonstrate that the EpCAM+CD45+ tumour cells over-express major histocompatibility complex class I antigen, which enable them to evade the natural killer cell-mediated immune surveillance. Preliminary evidence obtained in OVCAR-5 cells suggests that exosomes, secreted by non-tumour cells of the ascitic fluid, play an important role in rendering drug resistance and invasive properties to the cancer cells. Identification of such aggressive tumour cells and deciphering their origin is important for designing better drug targets for EOC.


Assuntos
Carcinoma Epitelial do Ovário/patologia , Proliferação de Células , Cistadenocarcinoma Seroso/patologia , Molécula de Adesão da Célula Epitelial/metabolismo , Antígenos Comuns de Leucócito/metabolismo , Neoplasias Ovarianas/patologia , Líquido Ascítico/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/metabolismo , Proliferação de Células/genética , Células Cultivadas , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Molécula de Adesão da Célula Epitelial/genética , Feminino , Humanos , Antígenos Comuns de Leucócito/genética , Invasividade Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Fenótipo , Carga Tumoral/genética
5.
J Exp Med ; 214(2): 423-437, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28082356

RESUMO

Inhibition of the IκB kinase complex (IKK) has been implicated in the therapy of several chronic inflammatory diseases including inflammatory bowel diseases. In this study, using mice with an inactivatable IKKα kinase (IkkαAA/AA), we show that loss of IKKα function markedly impairs epithelial regeneration in a model of acute colitis. Mechanistically, this is caused by compromised secretion of cytoprotective IL-18 from IKKα-mutant intestinal epithelial cells because of elevated caspase 12 activation during an enhanced unfolded protein response (UPR). Induction of the UPR is linked to decreased ATG16L1 stabilization in IkkαAA/AA mice. We demonstrate that both TNF-R and nucleotide-binding oligomerization domain stimulation promote ATG16L1 stabilization via IKKα-dependent phosphorylation of ATG16L1 at Ser278. Thus, we propose IKKα as a central mediator sensing both cytokine and microbial stimulation to suppress endoplasmic reticulum stress, thereby assuring antiinflammatory function during acute intestinal inflammation.


Assuntos
Proteínas de Transporte/metabolismo , Quinase I-kappa B/fisiologia , Inflamação/metabolismo , Animais , Proteínas Relacionadas à Autofagia , Proteínas de Transporte/química , Caspase 12/fisiologia , Colite/prevenção & controle , Estresse do Retículo Endoplasmático , Endorribonucleases/fisiologia , Interleucina-18/metabolismo , Camundongos , NF-kappa B/fisiologia , Proteína Adaptadora de Sinalização NOD2/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Estabilidade Proteica , Resposta a Proteínas não Dobradas
6.
Cancer Res ; 73(17): 5360-70, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23856249

RESUMO

For a long time, the external milieu of cancer cells was considered to be of secondary importance when compared with its intrinsic properties. That has changed now as the microenvironment is considered to be a major contributing factor toward the progression of tumor. In this study, we show that in human and mouse epithelial ovarian carcinoma and mouse lung carcinoma, the interaction between tumor-infiltrating hematopoietic cells and epithelial cancer cells results in their fusion. Intriguingly, even after the fusion event, cancer cells retain the expression of the pan-hematopoietic marker (CD45) and various markers of hematopoietic lineage, including those of hematopoietic stem cells, indicating that the hematopoietic genome is not completely reprogrammed. This observation may have implications on the bone marrow contribution to the cancer stem cell population. Interestingly, it was seen that in both cancer models, the expression of chemokine receptor CXCR4 was largely contributed to by the fused compartment of cancer cells. We hypothesize that the superior migratory potential gained by the cancer cells due to the fusion helps in its dissemination to various secondary organs upon activation of the CXCR4/CXCL12 axis. We are the first to report the presence of a hemato-epithelial cancer compartment, which contributes to stem cell markers and CXCR4 in epithelial carcinoma. This finding has repercussions on CXCR4-based therapeutics and opens new avenues in discovering novel molecular targets against fusion and metastasis.


Assuntos
Biomarcadores/metabolismo , Carcinoma Pulmonar de Lewis/patologia , Movimento Celular , Células Epiteliais/patologia , Células-Tronco Hematopoéticas/patologia , Neoplasias Epiteliais e Glandulares/patologia , Células-Tronco Neoplásicas/patologia , Neoplasias Ovarianas/patologia , Animais , Western Blotting , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/metabolismo , Carcinoma Epitelial do Ovário , Diferenciação Celular , Fusão Celular , Linhagem da Célula , Proliferação de Células , Quimiocina CXCL12/metabolismo , Quimiotaxia , Progressão da Doença , Células Epiteliais/metabolismo , Feminino , Citometria de Fluxo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Técnicas Imunoenzimáticas , Hibridização in Situ Fluorescente , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Fenótipo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores CXCR4/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Células Tumorais Cultivadas
7.
Stem Cells Dev ; 21(1): 110-20, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21480781

RESUMO

Hemophilia A (HA) is caused by mutation in factor VIII (FVIII) gene in humans; it leads to inadequate synthesis of active protein. Liver is the primary site of FVIII synthesis; however, the specific cell types responsible for its synthesis remain controversial. We propose that the severity of the bleeding disorder could be ameliorated by partial replacement of mutated liver cells by healthy cells in HA mice. The aim of this investigation was to study the cellular origin of FVIII by examining bone marrow cell therapy for treatment of HA in mice. Recipient liver was perturbed with either acetaminophen or monocrotaline to facilitate the engraftment and differentiation of lineage-depleted (Lin(-)) enhanced green fluorescent protein-expressing bone marrow cells. Immunohistochemical analysis of liver tissue was conducted to identify the donor-derived cells that expressed FVIII. This identification was confirmed by transmission electron microscopy and quantitative gene expression analysis. The phenotypic correction in HA mice was determined by tail-clip challenge and FVIII level in plasma by Chromogenix and activated partial thromboplastin time assays. Immunohistochemical analysis showed that von Willebrand factor and cytokeratin-18-expressing endothelial cells and hepatocytes, respectively, were obtained from BM-derived cells. Both cell types expressed FVIII light chain mRNA and protein, which was further confirmed by transmission electron microscopy. The transplanted HA mice showed FVIII activity in plasma (P<0.01) and survived tail-clip challenge (P<0.001). Thus, we conclude that BM-derived hepatocytes and endothelial cells can synthesize FVIII in liver and correct bleeding phenotype in HA mice.


Assuntos
Células da Medula Óssea/fisiologia , Células Endoteliais/metabolismo , Fator VIII/biossíntese , Hemofilia A/metabolismo , Hepatócitos/metabolismo , Fígado/metabolismo , Transplante de Células-Tronco , Células-Tronco/fisiologia , Acetaminofen , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Células da Medula Óssea/metabolismo , Diferenciação Celular , Células Endoteliais/ultraestrutura , Fator VIII/genética , Feminino , Expressão Gênica , Hemofilia A/patologia , Hepatócitos/ultraestrutura , Queratina-18/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco/metabolismo , Fator de von Willebrand/metabolismo
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