RESUMO
Pro-carcinogenic bacteria have the potential to initiate and/or promote colon cancer, in part via immune mechanisms that are incompletely understood. Using ApcMin mice colonized with the human pathobiont enterotoxigenic Bacteroides fragilis (ETBF) as a model of microbe-induced colon tumorigenesis, we show that the Bacteroides fragilis toxin (BFT) triggers a pro-carcinogenic, multi-step inflammatory cascade requiring IL-17R, NF-κB, and Stat3 signaling in colonic epithelial cells (CECs). Although necessary, Stat3 activation in CECs is not sufficient to trigger ETBF colon tumorigenesis. Notably, IL-17-dependent NF-κB activation in CECs induces a proximal to distal mucosal gradient of C-X-C chemokines, including CXCL1, that mediates the recruitment of CXCR2-expressing polymorphonuclear immature myeloid cells with parallel onset of ETBF-mediated distal colon tumorigenesis. Thus, BFT induces a pro-carcinogenic signaling relay from the CEC to a mucosal Th17 response that results in selective NF-κB activation in distal colon CECs, which collectively triggers myeloid-cell-dependent distal colon tumorigenesis.
Assuntos
Toxinas Bacterianas/imunologia , Bacteroides fragilis/imunologia , Carcinogênese/patologia , Colo/imunologia , Neoplasias Colorretais/etiologia , Células Epiteliais/imunologia , Interleucina-17/imunologia , Metaloendopeptidases/imunologia , Fator de Transcrição RelA/metabolismo , Proteína da Polipose Adenomatosa do Colo/genética , Animais , Toxinas Bacterianas/metabolismo , Bacteroides fragilis/patogenicidade , Linhagem Celular Tumoral , Colo/citologia , Colo/microbiologia , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais/patologia , Ativação Enzimática/imunologia , Feminino , Deleção de Genes , Células HT29 , Humanos , Inflamação/imunologia , Inflamação/microbiologia , Interleucina-17/genética , Masculino , Metaloendopeptidases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/imunologia , Receptores de Interleucina-17/genética , Receptores de Interleucina-17/imunologia , Receptores de Interleucina-8B/genética , Fator de Transcrição STAT3/metabolismoRESUMO
Individuals with sporadic colorectal cancer (CRC) frequently harbor abnormalities in the composition of the gut microbiome; however, the microbiota associated with precancerous lesions in hereditary CRC remains largely unknown. We studied colonic mucosa of patients with familial adenomatous polyposis (FAP), who develop benign precursor lesions (polyps) early in life. We identified patchy bacterial biofilms composed predominately of Escherichia coli and Bacteroides fragilis Genes for colibactin (clbB) and Bacteroides fragilis toxin (bft), encoding secreted oncotoxins, were highly enriched in FAP patients' colonic mucosa compared to healthy individuals. Tumor-prone mice cocolonized with E. coli (expressing colibactin), and enterotoxigenic B. fragilis showed increased interleukin-17 in the colon and DNA damage in colonic epithelium with faster tumor onset and greater mortality, compared to mice with either bacterial strain alone. These data suggest an unexpected link between early neoplasia of the colon and tumorigenic bacteria.
Assuntos
Polipose Adenomatosa do Colo/microbiologia , Polipose Adenomatosa do Colo/patologia , Bacteroides fragilis/patogenicidade , Biofilmes , Carcinogênese , Colo/microbiologia , Neoplasias do Colo/microbiologia , Escherichia coli/patogenicidade , Interleucina-17/análise , Animais , Toxinas Bacterianas/genética , Bacteroides fragilis/genética , Bacteroides fragilis/isolamento & purificação , Colo/patologia , Neoplasias do Colo/patologia , Dano ao DNA , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Microbioma Gastrointestinal , Humanos , Mucosa Intestinal/química , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Metaloendopeptidases/genética , Metaloendopeptidases/metabolismo , Camundongos , Peptídeos/genética , Peptídeos/metabolismo , Policetídeos , Lesões Pré-Cancerosas/microbiologiaRESUMO
High-mobility group A1 (Hmga1) chromatin remodelling proteins are enriched in intestinal stem cells (ISCs), although their function in this setting was unknown. Prior studies showed that Hmga1 drives hyperproliferation, aberrant crypt formation and polyposis in transgenic mice. Here we demonstrate that Hmga1 amplifies Wnt/ß-catenin signalling to enhance self-renewal and expand the ISC compartment. Hmga1 upregulates genes encoding both Wnt agonist receptors and downstream Wnt effectors. Hmga1 also helps to 'build' an ISC niche by expanding the Paneth cell compartment and directly inducing Sox9, which is required for Paneth cell differentiation. In human intestine, HMGA1 and SOX9 are positively correlated, and both become upregulated in colorectal cancer. Our results define a unique role for Hmga1 in intestinal homeostasis by maintaining the stem cell pool and fostering terminal differentiation to establish an epithelial stem cell niche. This work also suggests that deregulated Hmga1 perturbs this equilibrium during intestinal carcinogenesis.
Assuntos
Proteína HMGA1a/metabolismo , Mucosa Intestinal/metabolismo , Celulas de Paneth/metabolismo , Células-Tronco/metabolismo , Via de Sinalização Wnt , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Células Cultivadas , Proteína HMGA1a/genética , Humanos , Mucosa Intestinal/citologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia Confocal , Celulas de Paneth/citologia , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Nicho de Células-Tronco , Células-Tronco/citologia , Imagem com Lapso de TempoRESUMO
CASE DESCRIPTION A 9-year-old spayed female Rottweiler with hind limb ataxia was examined because of anorexia and an acute onset of hind limb paresis. CLINICAL FINDINGS Neurologic evaluation revealed hind limb ataxia and symmetric paraparesis with bilaterally abnormal hind limb postural reactions including hopping, hemiwalking, hemistanding, and delayed proprioception, which were suggestive of a lesion somewhere in the T3-L3 segment of the spinal cord. Thoracolumbar radiography revealed an abnormal radiopacity suggestive of a mass at T11. Two 3.5-cm-long osseous core biopsy specimens of the mass were obtained by MRI guidance. Histologic appearance of the specimens was consistent with osteosarcoma. TREATMENT AND OUTCOME The owners of the dog declined further treatment owing to a poor prognosis. The dog was euthanized within 12 months after diagnosis because of a declining quality of life. CLINICAL RELEVANCE The acquisition of biopsy specimens by MRI guidance is an emerging technique in veterinary medicine. As evidenced by the dog of this report, MRI-guided biopsy can be used to safely obtain diagnostic biopsy specimens from tissues at anatomic locations that are difficult to access. This technique can potentially be used to facilitate early diagnosis and treatment of disease, which could improve patient outcome. The MRI guidance technique described may also be useful for local administration of chemotherapeutics or radiofrequency ablation or cryoablation of various neoplasms of the vertebral column.
Assuntos
Neoplasias Ósseas/veterinária , Doenças do Cão/patologia , Imageamento por Ressonância Magnética/veterinária , Osteossarcoma/veterinária , Coluna Vertebral/patologia , Animais , Biópsia/veterinária , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Doenças do Cão/diagnóstico , Doenças do Cão/diagnóstico por imagem , Cães , Osteossarcoma/diagnóstico , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/patologiaRESUMO
Kabuki syndrome is a Mendelian intellectual disability syndrome caused by mutations in either of two genes (KMT2D and KDM6A) involved in chromatin accessibility. We previously showed that an agent that promotes chromatin opening, the histone deacetylase inhibitor (HDACi) AR-42, ameliorates the deficiency of adult neurogenesis in the granule cell layer of the dentate gyrus and rescues hippocampal memory defects in a mouse model of Kabuki syndrome (Kmt2d+/ßGeo). Unlike a drug, a dietary intervention could be quickly transitioned to the clinic. Therefore, we have explored whether treatment with a ketogenic diet could lead to a similar rescue through increased amounts of beta-hydroxybutyrate, an endogenous HDACi. Here, we report that a ketogenic diet in Kmt2d+/ßGeo mice modulates H3ac and H3K4me3 in the granule cell layer, with concomitant rescue of both the neurogenesis defect and hippocampal memory abnormalities seen in Kmt2d+/ßGeo mice; similar effects on neurogenesis were observed on exogenous administration of beta-hydroxybutyrate. These data suggest that dietary modulation of epigenetic modifications through elevation of beta-hydroxybutyrate may provide a feasible strategy to treat the intellectual disability seen in Kabuki syndrome and related disorders.
Assuntos
Anormalidades Múltiplas/dietoterapia , Dieta Cetogênica/métodos , Face/anormalidades , Doenças Hematológicas/dietoterapia , Hipocampo/metabolismo , Histonas/biossíntese , Deficiência Intelectual/dietoterapia , Neurogênese/fisiologia , Doenças Vestibulares/dietoterapia , Ácido 3-Hidroxibutírico/metabolismo , Anormalidades Múltiplas/genética , Animais , Modelos Animais de Doenças , Doenças Hematológicas/genética , Hipocampo/citologia , Histona Desmetilases/genética , Histona-Lisina N-Metiltransferase/genética , Deficiência Intelectual/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteína de Leucina Linfoide-Mieloide/genética , Neurogênese/genética , Doenças Vestibulares/genéticaRESUMO
AIM: To determine the temporal expression and pattern of Rel/nuclear factor (NF)-κB proteins in renal tissue in polycystic kidney disease (PKD). METHODS: The renal expression of Rel/NF-κB proteins was determined by immunohistochemistry, immunofluorescence and immunoblot analysis in Lewis polycystic kidney rats (LPK, a genetic ortholog of human nephronopthsis-9) from postnatal weeks 3 to 20. At each timepoint, renal disease progression and the mRNA expression of NF-κB-dependent genes (TNFα and CCL2) were determined. NF-κB was also histologically assessed in human PKD tissue. RESULTS: Progressive kidney enlargement in LPK rats was accompanied by increased renal cell proliferation and interstitial monocyte accumulation (peaking at weeks 3 and 10 respectively), and progressive interstitial fibrosis (with α smooth muscle actin and Sirius Red deposition significantly increased compared to Lewis kidneys from weeks 3 to 6 onwards). Rel/NF-κB proteins (phosphorylated-p105, p65, p50, c-Rel and RelB) were expressed in cystic epithelial cells (CECs) of LPK kidneys as early as postnatal week 3 and sustained until late-stage disease at week 20. From weeks 10 to 20, nuclear p65, p50, RelB and cytoplasmic IκBα protein levels, and TNFα and CCL2 expression, were upregulated in LPK compared to Lewis kidneys. NF-κB proteins were consistently expressed in CECs of human PKD. The DNA damage marker γ-H2AX was also identified in the CECs of LPK and human polycystic kidneys. CONCLUSION: Several NF-κB proteins are consistently expressed in CECs in human and experimental PKD. These data suggest that the upregulation of both the canonical and non-canonical pathways of NF-κB signaling may be a constitutive and early pathological feature of cystic renal diseases.
RESUMO
Abnormal proliferation of cyst-lining epithelium and increased intracystic fluid secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) are thought to contribute to cyst growth in autosomal dominant polycystic kidney disease (ADPKD). Histone deacetylase 6 (HDAC6) expression and activity are increased in certain cancers, neurodegenerative diseases, and in Pkd1-mutant renal epithelial cells. Inhibition of HDAC6 activity with specific inhibitors slows cancer growth. Here we studied the effect of tubacin, a specific HDAC6 inhibitor, on cyst growth in polycystic kidney disease. Treatment with tubacin prevented cyst formation in MDCK cells, an in vitro model of cystogenesis. Cyclic AMP stimulates cell proliferation and activates intracystic CFTR-mediated chloride secretion in ADPKD. Treatment with tubacin downregulated cyclic AMP levels, inhibited cell proliferation, and inhibited cyclic AMP-activated CFTR chloride currents in MDCK cells. We also found that tubacin reduced cyst growth by inhibiting proliferation of cyst-lining epithelial cells, downregulated cyclic AMP levels, and improved renal function in a Pkd1-conditional mouse model of ADPKD. Thus, HDAC6 could play a role in cyst formation and could serve as a potential therapeutic target in ADPKD.
Assuntos
Anilidas/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Células Epiteliais/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Ácidos Hidroxâmicos/farmacologia , Rim/efeitos dos fármacos , Rim Policístico Autossômico Dominante/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Cloretos/sangue , Cloretos/metabolismo , AMP Cíclico/sangue , Modelos Animais de Doenças , Cães , Regulação para Baixo , Células Epiteliais/metabolismo , Feminino , Desacetilase 6 de Histona , Histona Desacetilases/genética , Humanos , Rim/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Rim Policístico Autossômico Dominante/genética , Canais de Cátion TRPP/genéticaRESUMO
The standard treatment for ductal carcinoma in situ (DCIS) of the breast is surgical resection, followed by radiation. Here, we tested localized therapy of DCIS in mice using the immunoconjugate 225Ac linked-trastuzumab delivered through the intraductal (i.duc) route. Trastuzumab targets HER-2/neu, while the alpha-emitter 225Ac (half-life, 10 days) delivers highly cytotoxic, focused doses of radiation to tumors. Systemic 225Ac, however, elicits hematologic toxicity and at high doses free 213Bi, generated by its decay, causes renal toxicity. I.duc delivery of the radioimmunoconjugate could bypass its systemic toxicity. Bioluminescent imaging showed that the therapeutic efficacy of intraductal 225Ac-trastuzumab (10-40 nCi per mammary gland; 30-120 nCi per mouse) in a DCIS model of human SUM225 cancer cells in NSG mice was significantly higher (p<0.0003) than intravenous (120 nCi per mouse) administration, with no kidney toxicity or loss of body weight. Our findings suggest that i.duc radioimmunotherapy using 225Ac-trastuzumab deserves greater attention for future clinical development as a treatment modality for early breast cancer.
Assuntos
Actínio/administração & dosagem , Partículas alfa , Neoplasias da Mama/radioterapia , Carcinoma Intraductal não Infiltrante/radioterapia , Imunoconjugados/administração & dosagem , Radioimunoterapia/métodos , Radioisótopos/administração & dosagem , Compostos Radiofarmacêuticos/administração & dosagem , Receptor ErbB-2/metabolismo , Trastuzumab/administração & dosagem , Actínio/farmacocinética , Actínio/toxicidade , Partículas alfa/efeitos adversos , Animais , Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/imunologia , Carcinoma Intraductal não Infiltrante/metabolismo , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Humanos , Imunoconjugados/farmacocinética , Células MCF-7 , Camundongos Endogâmicos NOD , Radioimunoterapia/efeitos adversos , Radioisótopos/farmacocinética , Radioisótopos/toxicidade , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/toxicidade , Receptor ErbB-2/imunologia , Distribuição Tecidual , Trastuzumab/farmacocinética , Carga Tumoral/efeitos da radiação , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVES: Although uterine cancer is the fourth most common cause for cancer death in women worldwide, the molecular underpinnings of tumor progression remain poorly understood. The High Mobility Group A1 (HMGA1) gene is overexpressed in aggressive cancers and high levels portend adverse outcomes in diverse tumors. We previously reported that Hmga1a transgenic mice develop uterine tumors with complete penetrance. Because HMGA1 drives tumor progression by inducing MatrixMetalloproteinase (MMP) and other genes involved in invasion, we explored the HMGA1-MMP-2 pathway in uterine cancer. METHODS: To investigate MMP-2 in uterine tumors driven by HMGA1, we used a genetic approach with mouse models. Next, we assessed HMGA1 and MMP-2 expression in primary human uterine tumors, including low-grade carcinomas (endometrial endometrioid) and more aggressive tumors (endometrial serous carcinomas, uterine carcinosarcomas/malignant mesodermal mixed tumors). RESULTS: Here, we report for the first time that uterine tumor growth is impaired in Hmga1a transgenic mice crossed on to an Mmp-2 deficient background. In human tumors, we discovered that HMGA1 is highest in aggressive carcinosarcomas and serous carcinomas, with lower levels in the more indolent endometrioid carcinomas. Moreover, HMGA1 and MMP-2 were positively correlated, but only in a subset of carcinosarcomas. HMGA1 also occupies the MMP-2 promoter in human carcinosarcoma cells. CONCLUSIONS: Together, our studies define a novel HMGA1-MMP-2 pathway involved in a subset of human carcinosarcomas and tumor progression in murine models. Our work also suggests that targeting HMGA1 could be effective adjuvant therapy for more aggressive uterine cancers and provides compelling data for further preclinical studies.
Assuntos
Carcinossarcoma/genética , Cistadenocarcinoma Seroso/genética , Proteína HMGA1a/genética , Metaloproteinase 2 da Matriz/genética , Neoplasias Uterinas/genética , Animais , Carcinossarcoma/metabolismo , Imunoprecipitação da Cromatina , Cistadenocarcinoma Seroso/metabolismo , Feminino , Inativação Gênica , Proteína HMGA1a/biossíntese , Humanos , Masculino , Metaloproteinase 2 da Matriz/biossíntese , Camundongos Transgênicos , Regiões Promotoras Genéticas , Regulação para Cima , Neoplasias Uterinas/metabolismoAssuntos
Ácidos Aminossalicílicos/farmacologia , Antineoplásicos/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Células Precursoras de Linfócitos B/efeitos dos fármacos , Sulfonamidas/farmacologia , Animais , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Proteína HMGA1a/genética , Proteína HMGA1a/metabolismo , Humanos , Células Jurkat , Camundongos , Camundongos Nus , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Células Precursoras de Linfócitos B/metabolismo , Células Precursoras de Linfócitos B/patologia , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Chronic inflammation and composition of the colon microbiota have been associated with colorectal cancer in humans. The human commensal enterotoxigenic Bacteroides fragilis (ETBF) is linked to both inflammatory bowel disease and colorectal cancer and, in our murine model, causes interleukin 17A (IL-17A)-dependent colon tumors. In these studies, we hypothesized that persistent colonization by ETBF is required for tumorigenesis. METHODS: We established a method for clearing ETBF in mice, using the antibiotic cefoxitin. Multiple intestinal neoplasia mice were colonized with ETBF for the experiment duration or were cleared of infection after 5 or 14 days. Gross tumors and/or microadenomas were then evaluated. In parallel, IL-17A expression was evaluated in wild-type littermates. RESULTS: Cefoxitin treatment resulted in complete and durable clearance of ETBF colonization. We observed a stepwise increase in median colon tumor numbers as the duration of ETBF colonization increased before cefoxitin treatment. ETBF eradication also significantly decreased mucosal IL-17A expression. CONCLUSIONS: The timing of ETBF clearance profoundly influences colon adenoma formation, defining a period during which the colon is susceptible to IL-17A-dependent tumorigenesis in this murine model. This model system can be used to study the microbiota-dependent and molecular mechanisms contributing to IL-17A-dependent colon tumor initiation.
Assuntos
Carcinogênese/efeitos dos fármacos , Cefoxitina/efeitos adversos , Transformação Celular Neoplásica/efeitos dos fármacos , Neoplasias do Colo/complicações , Neoplasias do Colo/tratamento farmacológico , Enterotoxinas/efeitos adversos , Enterotoxinas/uso terapêutico , Animais , Bacteroides fragilis/química , Colo/microbiologia , Neoplasias do Colo/microbiologia , Humanos , CamundongosRESUMO
IL17-producing Th17 cells, generated through a STAT3-dependent mechanism, have been shown to promote carcinogenesis in many systems, including microbe-driven colon cancer. Additional sources of IL17, such as γδ T cells, become available under inflammatory conditions, but their contributions to cancer development are unclear. In this study, we modeled Th17-driven colon tumorigenesis by colonizing Min(Ap) (c+/-) mice with the human gut bacterium, enterotoxigenic Bacteroides fragilis (ETBF), to investigate the link between inflammation and colorectal cancer. We found that ablating Th17 cells by knocking out Stat3 in CD4(+) T cells delayed tumorigenesis, but failed to suppress the eventual formation of colonic tumors. However, IL17 blockade significantly attenuated tumor formation, indicating a critical requirement for IL17 in tumorigenesis, but from a source other than Th17 cells. Notably, genetic ablation of γδ T cells in ETBF-colonized Th17-deficient Min mice prevented the late emergence of colonic tumors. Taken together, these findings support a redundant role for adaptive Th17 cell- and innate γδT17 cell-derived IL17 in bacteria-induced colon carcinogenesis, stressing the importance of therapeutically targeting the cytokine itself rather than its cellular sources. Cancer Res; 76(8); 2115-24. ©2016 AACR.
Assuntos
Imunidade Adaptativa , Neoplasias do Colo/patologia , Imunidade Inata , Interleucina-17/biossíntese , Animais , Antígenos CD4/imunologia , Carcinogênese , Neoplasias do Colo/imunologia , Neoplasias do Colo/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Efforts to induce the differentiation of cancer stem cells through treatment with all-trans retinoic acid (ATRA) have yielded limited success, partially due to the epigenetic silencing of the retinoic acid receptor (RAR)-ß The histone deacetylase inhibitor entinostat is emerging as a promising antitumor agent when added to the standard-of-care treatment for breast cancer. However, the combination of epigenetic, cellular differentiation, and chemotherapeutic approaches against triple-negative breast cancer (TNBC) has not been investigated. In this study, we found that combined treatment of TNBC xenografts with entinostat, ATRA, and doxorubicin (EAD) resulted in significant tumor regression and restoration of epigenetically silenced RAR-ß expression. Entinostat and doxorubicin treatment inhibited topoisomerase II-ß (TopoII-ß) and relieved TopoII-ß-mediated transcriptional silencing of RAR-ß Notably, EAD was the most effective combination in inducing differentiation of breast tumor-initiating cells in vivo Furthermore, gene expression analysis revealed that the epithelium-specific ETS transcription factor-1 (ESE-1 or ELF3), known to regulate proliferation and differentiation, enhanced cell differentiation in response to EAD triple therapy. Finally, we demonstrate that patient-derived metastatic cells also responded to treatment with EAD. Collectively, our findings strongly suggest that entinostat potentiates doxorubicin-mediated cytotoxicity and retinoid-driven differentiation to achieve significant tumor regression in TNBC. Cancer Res; 76(7); 2013-24. ©2016 AACR.
Assuntos
Epigênese Genética/genética , Células-Tronco Neoplásicas/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Diferenciação Celular , Linhagem Celular Tumoral , HumanosRESUMO
UNLABELLED: Many epithelial cancers are associated with chronic inflammation. However, the features of inflammation that are procarcinogenic are not fully understood. Regulatory T cells (Treg) typically restrain overt inflammatory responses and maintain intestinal immune homeostasis. Their immune-suppressive activity can inhibit inflammation-associated cancers. Paradoxically, we show that colonic Tregs initiate IL17-mediated carcinogenesis in multiple intestinal neoplasia mice colonized with the human symbiote enterotoxigenic Bacteroides fragilis (ETBF). Depletion of Tregs in ETBF-colonized C57BL/6 FOXP3(DTR) mice enhanced colitis but diminished tumorigenesis associated with shifting of mucosal cytokine profile from IL17 to IFNγ; inhibition of ETBF-induced colon tumorigenesis was dependent on reduced IL17 inflammation and was independent of IFNγ. Treg enhancement of IL17 production is cell-extrinsic. IL2 blockade restored Th17 responses and tumor formation in Treg-depleted animals. Our findings demonstrate that Tregs limit the availability of IL2 in the local microenvironment, allowing the Th17 development necessary to promote ETBF-triggered neoplasia, and thus unveil a new mechanism whereby Treg responses to intestinal bacterial infection can promote tumorigenesis. SIGNIFICANCE: Tregs promote an oncogenic immune response to a common human symbiote associated with inflammatory bowel disease and colorectal cancer. Our data define mechanisms by which mucosal Tregs, despite suppressing excessive inflammation, promote the earliest stages of immune procarcinogenesis via enhancement of IL17 production at the expense of IFNγ production.
Assuntos
Infecções por Bacteroides/complicações , Bacteroides fragilis/fisiologia , Transformação Celular Neoplásica , Neoplasias do Colo/etiologia , Neoplasias do Colo/metabolismo , Interleucina-17/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Infecções por Bacteroides/microbiologia , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Interleucina-2/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Depleção Linfocítica , Camundongos , Camundongos Transgênicos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th17/imunologia , Células Th17/metabolismoRESUMO
FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutations resulting in constitutive kinase activity are common in acute myeloid leukemia (AML) and carry a poor prognosis. Several agents targeting FLT3 have been developed, but their limited clinical activity suggests that the inhibition of other factors contributing to the malignant phenotype is required. We examined gene expression data sets as well as primary specimens and found that the expression of GLI2, a major effector of the Hedgehog (Hh) signaling pathway, was increased in FLT3-ITD compared to wild-type FLT3 AML. To examine the functional role of the Hh pathway, we studied mice in which Flt3-ITD expression results in an indolent myeloproliferative state and found that constitutive Hh signaling accelerated the development of AML by enhancing signal transducer and activator of transcription 5 (STAT5) signaling and the proliferation of bone marrow myeloid progenitors. Furthermore, combined FLT3 and Hh pathway inhibition limited leukemic growth in vitro and in vivo, and this approach may serve as a therapeutic strategy for FLT3-ITD AML.
Assuntos
Proteínas Hedgehog/metabolismo , Leucemia Mieloide Aguda/metabolismo , Proteínas Mutantes/metabolismo , Transdução de Sinais , Tirosina Quinase 3 Semelhante a fms/metabolismo , Animais , Compartimento Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Progressão da Doença , Sinergismo Farmacológico , Duplicação Gênica/efeitos dos fármacos , Humanos , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Transtornos Mieloproliferativos/patologia , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Proteínas Nucleares/metabolismo , Compostos de Fenilureia/farmacologia , Receptores Acoplados a Proteínas G/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor Smoothened , Sorafenibe , Células-Tronco/citologia , Alcaloides de Veratrum/farmacologia , Proteína Gli2 com Dedos de ZincoRESUMO
Acquired resistance to TGFß is a key step in the early stages of tumorigenesis. Mutations in TGFß signaling components are rare, and little is known about the development of resistance in breast cancer. On the other hand, an activated Notch pathway is known to play a substantial role in promoting breast cancer development. Here, we present evidence of crosstalk between these two pathways through HEYL. HEYL, a basic helix-loop-helix transcription factor and a direct target of Notch signaling, is specifically overexpressed in breast cancer. HEYL represses TGFß activity by binding to TGFß-activated Smads. HeyL(-/-) mice have defective mammary gland development with fewer terminal end buds. On the other hand, HeyL transgenic mice show accelerated mammary gland epithelial proliferation and 24% of multiparous mice develop mammary gland cancer. Therefore, repression of TGFß signaling by Notch acting through HEYL may promote initiation of breast cancer.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Neoplasias da Mama/patologia , Receptores Notch/fisiologia , Proteínas Repressoras/fisiologia , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Células Cultivadas , Feminino , Humanos , Camundongos , Camundongos Transgênicos , Transdução de Sinais/efeitos dos fármacos , Proteína Smad3/fisiologiaRESUMO
Autosomal-dominant polycystic kidney disease (ADPKD) is a progressive, proliferative renal disease. Kidneys from ADPKD patients are characterized by the presence of cysts that are marked by enhanced proliferation and apoptosis of renal tubular epithelial cells. Current treatment of this disease is supportive, as there are few if any clinically validated targeted therapeutics. Given the parallels between cystic disease and cancer, and in light of our findings of the efficacy of the nuclear transport inhibitors in kidney cancer, which has similarities to ADPKD, we asked whether such inhibitors show utility in ADPKD. In this study, we tested selective inhibitors of nuclear export (SINE) in two human ADPKD cell lines and in an in vivo mouse model of ADPKD. After effective downregulation of a nuclear exporter, exportin 1 (XPO1), with KPT-330, both cell lines showed dose-dependent inhibition of cell proliferation through G0/G1 arrest associated with downregulation of CDK4, with minimal apoptosis. To analyze mechanisms of CDK4 decrease by XPO1 inhibition, localization of various XPO1 target proteins was examined, and C/EBPß was found to be localized in the nucleus by XPO1 inhibition, resulting in an increase of C/EBPα, which activates degradation of CDK4. Furthermore, inhibition of XPO1 with the parallel inhibitor KPT-335 attenuated cyst growth in vivo in the PKD1 mutant mouse model Pkd1(v/v). Thus, inhibition of nuclear export by KPT-330, which has shown no adverse effects in renal serum chemistries and urinalyses in animal models, and which is already in phase 1 trials for cancers, will be rapidly translatable to human ADPKD.
Assuntos
Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Quinase 4 Dependente de Ciclina/biossíntese , Cistos/patologia , Rim Policístico Autossômico Dominante/tratamento farmacológico , Rim Policístico Autossômico Dominante/patologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Humanos , Hidrazinas/farmacologia , Carioferinas/antagonistas & inibidores , Camundongos , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Canais de Cátion TRPP/genética , Canais de Cátion TRPP/metabolismo , Triazóis/farmacologia , Proteína Exportina 1RESUMO
Species of Clostridium bacteria are notable for their ability to lyse tumor cells growing in hypoxic environments. We show that an attenuated strain of Clostridium novyi (C. novyi-NT) induces a microscopically precise, tumor-localized response in a rat orthotopic brain tumor model after intratumoral injection. It is well known, however, that experimental models often do not reliably predict the responses of human patients to therapeutic agents. We therefore used naturally occurring canine tumors as a translational bridge to human trials. Canine tumors are more like those of humans because they occur in animals with heterogeneous genetic backgrounds, are of host origin, and are due to spontaneous rather than engineered mutations. We found that intratumoral injection of C. novyi-NT spores was well tolerated in companion dogs bearing spontaneous solid tumors, with the most common toxicities being the expected symptoms associated with bacterial infections. Objective responses were observed in 6 of 16 dogs (37.5%), with three complete and three partial responses. On the basis of these encouraging results, we treated a human patient who had an advanced leiomyosarcoma with an intratumoral injection of C. novyi-NT spores. This treatment reduced the tumor within and surrounding the bone. Together, these results show that C. novyi-NT can precisely eradicate neoplastic tissues and suggest that further clinical trials of this agent in selected patients are warranted.
Assuntos
Clostridium/fisiologia , Injeções Intralesionais , Neoplasias/microbiologia , Neoplasias/terapia , Animais , Cães , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Necrose , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Ratos , Reprodutibilidade dos Testes , Sarcoma/diagnóstico por imagem , Sarcoma/patologia , Sarcoma/terapia , Esporos Bacterianos , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Autosomal dominant polycystic kidney disease is a common form of inherited kidney disease that is caused by mutations in two genes, PKD1 (polycystin-1) and PKD2 (polycystin-2). Mice with germline deletion of either gene die in midgestation with a vascular phenotype that includes profound edema. Although an endothelial cell defect has been suspected, the basis of this phenotype remains poorly understood. Here, we demonstrate that edema in Pkd1- and Pkd2-null mice is likely to be caused by defects in lymphatic development. Pkd1 and Pkd2 mutant embryos exhibit reduced lymphatic vessel density and vascular branching along with aberrant migration of early lymphatic endothelial cell precursors. We used cell-based assays to confirm that PKD1- and PKD2-depleted endothelial cells have an intrinsic defect in directional migration that is associated with a failure to establish front-rear polarity. Our studies reveal a role for polycystin signaling in lymphatic development.