RESUMO
Helicobacter pylori infection predisposes carriers to a high risk of developing gastric cancer. The cell-of-origin of antral gastric cancer is the Lgr5+ stem cell. Here, we show that infection of antrum-derived gastric organoid cells with H. pylori increases the expression of the stem cell marker Lgr5 as determined by immunofluorescence microscopy, qRT-PCR, and Western blotting, both when cells are grown and infected as monolayers and when cells are exposed to H. pylori in 3D structures. H. pylori exposure increases stemness properties as determined by spheroid formation assay. Lgr5 expression and the acquisition of stemness depend on a functional type IV secretion system (T4SS) and at least partly on the T4SS effector CagA. The pharmacological inhibition or genetic ablation of NF-κB reverses the increase in Lgr5 and spheroid formation. Constitutively active Wnt/ß-catenin signaling because of Apc inactivation exacerbates H. pylori-induced Lgr5 expression and stemness, both of which persist even after eradication of the infection. The combined data indicate that H. pylori has stemness-inducing properties that depend on its ability to activate NF-κB signaling.
Assuntos
Infecções por Helicobacter , Helicobacter pylori , NF-kappa B , Receptores Acoplados a Proteínas G , Neoplasias Gástricas , Via de Sinalização Wnt , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Humanos , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/microbiologia , Via de Sinalização Wnt/genética , NF-kappa B/metabolismo , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Organoides/metabolismo , Organoides/microbiologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Células-Tronco/metabolismo , Antígenos de Bactérias/metabolismo , Antígenos de Bactérias/genética , Sistemas de Secreção Tipo IV/metabolismo , Sistemas de Secreção Tipo IV/genética , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/microbiologia , Estômago/microbiologia , Estômago/patologiaRESUMO
Porphyromonas gingivalis (P. gingivalis) is a keystone periodontal pathogen associated with various digestive cancers. However, whether P. gingivalis can promote colorectal cancer and the underlying mechanism associated with such promotion remains unclear. In this study, we found that P. gingivalis was enriched in human feces and tissue samples from patients with colorectal cancer compared with those from patients with colorectal adenoma or healthy subjects. Cohort studies demonstrated that P. gingivalis infection was associated with poor prognosis in colorectal cancer. P. gingivalis increased tumor counts and tumor volume in the ApcMin/+ mouse model and increased tumor growth in orthotopic rectal and subcutaneous carcinoma models. Furthermore, orthotopic tumors from mice exposed to P. gingivalis exhibited tumor-infiltrating myeloid cell recruitment and a proinflammatory signature. P. gingivalis promoted colorectal cancer via NLRP3 inflammasome activation in vitro and in vivo. NLRP3 chimeric mice harboring orthotopic tumors showed that the effect of NLRP3 on P. gingivalis pathogenesis was mediated by hematopoietic sources. Collectively, these data suggest that P. gingivalis contributes to colorectal cancer neoplasia progression by activating the hematopoietic NLRP3 inflammasome. SIGNIFICANCE: This study demonstrates that the periodontal pathogen P. gingivalis can promote colorectal tumorigenesis by recruiting myeloid cells and creating a proinflammatory tumor microenvironment. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/10/2745/F1.large.jpg.
Assuntos
Carcinogênese/patologia , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Inflamassomos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Células-Tronco Neoplásicas/patologia , Porphyromonas gingivalis/patogenicidade , Animais , Apoptose , Infecções por Bacteroidaceae/complicações , Infecções por Bacteroidaceae/imunologia , Infecções por Bacteroidaceae/microbiologia , Infecções por Bacteroidaceae/patologia , Carcinogênese/imunologia , Carcinogênese/metabolismo , Proliferação de Células , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/microbiologia , Humanos , Inflamassomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Células Mieloides/imunologia , Células Mieloides/metabolismo , Células Mieloides/microbiologia , Células Mieloides/patologia , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/microbiologia , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Microambiente Tumoral/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: The main cause of gastric cancer is the infection by the bacterium Helicobacter pylori which induces a chronic inflammation and an epithelial-to-mesenchymal transition (EMT) leading to the emergence of cells with cancer stem cell (CSC) properties. However, the underlying mechanisms have not been fully characterized. Moreover, H. pylori modulates the host cell autophagic process, but a few studies have investigated the role of this process in tumoral transformation. The aim of this study was to determine whether H. pylori-induced autophagy has a role in CSC emergence. METHODS: Autophagic flux in response to H. pylori infection was characterized in AGS cell line expressing the tandem-tagged mCherry-GFP-LC3 protein and using a ratiometric flow cytometry analysis. Then, AGS and MKN45 cell lines were treated with bafilomycin or chloroquine, two pharmaceutical well-known inhibitors of autophagy, and different EMT and CSC characteristics were analyzed. RESULTS: First, a co-expression of the gastric CSC marker CD44 and the autophagic marker LC3 in mice and human stomach tissues infected with H. pylori was observed. Then, we demonstrated in vitro that H. pylori was able to activate the autophagy process with a reduced autophagic flux. Finally, infected cells were treated with autophagy inhibitors, which reduced (i) appearance of mesenchymal phenotypes and migration ability related to EMT and (ii) CD44 expression as well as tumorsphere formation capacities reflecting CSC properties. CONCLUSION: In conclusion, all these data show that H. pylori-induced autophagy is implicated in gastric CSC emergence and could represent an interesting therapeutic target.
Assuntos
Autofagia/fisiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/fisiologia , Células-Tronco Neoplásicas/microbiologia , Neoplasias Gástricas/microbiologia , Animais , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Infecções por Helicobacter/complicações , Humanos , Receptores de Hialuronatos/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Estômago/citologia , Estômago/microbiologiaRESUMO
Growing evidence suggests that microbes can influence the onset of cancer and its consequent development. By researching samples from patients afflicted by cervical cancer, we aimed to explore the associated dynamics and prognostic value of intratumoral levels of F. nucleatum. We used qPCR to analyze tumor tissues obtained from 112 cervical cancer patients in order to characterize the levels and influences of intratumoral levels of the F. nucleatum. Especially for recurrent tissues, there was a distinct observation of higher levels of F. nucleatum in cervical cancer. Patients with high burdens of F. nucleatum intratumoral infiltration exhibited correspondingly poor rates of both overall survival and progression-free survival. Measures of the levels of F. nucleatum were found to have been reliable independent prognostic factors that could predict rates of PFS for afflicted patients (HR = 4.8, 95%CI = 1.2-18.6, P = 0.024). Notably, the levels ofF. nucleatum were positively correlated with tumor differentiation. Cancer cells from patients with relatively high levels of F. nucleatum were observed to possess the characteristics of cancer stem cells (CSCs). We propose that F. nucleatum might be one potential cervical cancer diagnostic and prognostic biomarker, and these findings will help to provide a sound rationale and merit for further study of this bacterium.
Assuntos
Fusobacterium nucleatum/isolamento & purificação , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/microbiologia , Adulto , Feminino , Humanos , Células-Tronco Neoplásicas/microbiologia , Prognóstico , Análise de Sobrevida , Neoplasias do Colo do Útero/mortalidadeRESUMO
Bacteria is recognized as opportunistic tumor inhabitant, giving rise to an environmental stress that may alter tumor microenvironment, which directs cancer behavior. In vitro infection of the T24 cell line with E. coli was performed to study the bacterial impact on bladder cancer cells. EMT markers were assessed using immunohistochemistry, western blot and RT-PCR. Stemness characteristics were monitored using RT-PCR. Furthermore, the metabolic reprograming was investigated by detection of ROS and metabolic markers. A significant (p ≤ 0.001) upregulation of vimentin as well as downregulation of CK19 transcription and protein levels was reported. A significant increase (p ≤ 0.001) in the expression level of stemness markers (CD44, NANOG, SOX2 and OCT4) was reported. ROS level was elevated, that led to a significant increase (p ≤ 0.001) in UCP2. This enhanced a significant increase (p ≤ 0.001) in PDK1 to significantly downregulate PDH (p ≤ 0.001) in order to block oxidative phosphorylation in favor of glycolysis. This resulted in a significant decrease (p ≤ 0.001) of AMPK, and a significant elevation (p ≤ 0.001) of MCT1 to export the produced lactate to extracellular matrix. Thus, bacteria may induce alteration to the heterogonous tumor cell population through EMT, CSCs and metabolic reprogramming, which may improve cancer cell ability to migrate and self-renew.
Assuntos
Reprogramação Celular , Infecções por Escherichia coli/complicações , Escherichia coli/patogenicidade , Células-Tronco Neoplásicas/patologia , Neoplasias da Bexiga Urinária/patologia , Apoptose , Proliferação de Células , Progressão da Doença , Transição Epitelial-Mesenquimal , Infecções por Escherichia coli/microbiologia , Humanos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/microbiologia , Células Tumorais Cultivadas , Microambiente Tumoral , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/microbiologiaRESUMO
The enrichment of Enterotoxigenic Bacteroides fragilis (ETBF) has been identified in CRC patients and associated with worse prognosis. Cancer stem cells (CSCs) play essential roles in CRC development. However, whether ETBF is involved in CSCs regulation is unknown. To clarify the role of ETBF in CSCs properties, we performed extreme limited dilution assays (ELDA) in nude mice injected with ETBF-treated or untreated CRC cells subcutaneously, tumor organoids culture in azoxymethane (AOM) mouse model after gavaging with or without ETBF, and cell sphere formation assay after incubating CRC cell lines with or without ETBF. The results indicated that ETBF increased the stemness of CRC cells in vivo and in vitro. Furthermore, ETBF enhanced the expression of core stemness transcription factors Nanog homeobox (NANOG) and sex determining region Y-box 2 (SOX2). Histone H3 Lysine 9 trimethylation (H3K9me3) is critical in regulating CSCs properties. As an epigenetic and transcriptional regulator, JmjC-domain containing histone demethylase 2B (JMJD2B) is essential for embryonic stem cell (ESC) transformation and H3K9me3 demethylation. Mechanistically, ETBF infection significantly upregulated JMJD2B levels in CRC cell lines and nude mice xenograft model. JMJD2B epigenetically upregulated NANOG expression via demethylating its promoter H3K9me3, to mediate ETBF-induced stemness of CRC cells. Subsequently, we found that the Toll-like receptor 4 (TLR4) pathway, activated by ETBF, contributed to the enhanced expression of JMJD2B via nuclear transcription factor nuclear factor of activated T cells 5 (NFAT5). Finally, in human CRC samples, the amount of ETBF positively correlated with nuclear NFAT5, JMJD2B, and NANOG expression levels. In summary, ETBF upregulated JMJD2B levels in a TLR4-NFAT5-dependent pathway, and played an important role in stemness regulation, which promoted colorectal carcinogenesis.
Assuntos
Bacteroides fragilis/patogenicidade , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais/patologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Animais , Bacteroides fragilis/metabolismo , Carcinogênese/metabolismo , Carcinogênese/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Proteína Homeobox Nanog/genética , Proteína Homeobox Nanog/metabolismo , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/microbiologia , Células-Tronco Neoplásicas/patologia , Prognóstico , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Receptor 4 Toll-Like/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Accumulating evidence suggests that human hepatocellular carcinoma (HCC) can be derived from cancer stem cells (CSCs), which contribute to tumor initiation, metastasis, chemoresistance, and recurrence. A great variety of HCC CSCs resulting in diverse clinical manifestations have been reported. However, how CSC diversity is regulated and generated remains unclear. Here we report that the miR-200b-ZEB1 circuit is closely involved with the induction and maintenance of a diverse group of CSCs. We found that miR-200b downregulation occurred in early HCC and associated with poor prognosis. The downregulation was attributable to genome deletion and promoter methylation of the miR-200a/b/429 gene. Ectopic expression of miR-200b or silencing of ZEB1 led to a decrease in CD13+ and CD24+ HCC CSCs and an increase in EpCAM+ HCC CSCs. Mechanistically, miR-200b directly suppressed BMI1 and ZEB1 expressions. ZEB1 recognized promoters of CD13, CD24, and EpCAM genes resulting in CD13 and CD24 upregulation and EpCAM downregulation. Neither miR-200b nor ZEB1 had obvious effects on CD133 or CD90 expression. Silencing CD13 or CD24 expression suppressed tumorigenicity of HCC cells. Ectopic expression of CD24 reversed the suppression of tumorigenicity by ectopic expression of miR-200b. Clinically, miR-200b downregulation was coupled with ZEB1 upregulation in approximately two-thirds of HCC patients. ZEB1 expression was positively correlated with CD13 and CD24 expressions in HCCs, while miR-200b expression was positively correlated with EpCAM. Our findings suggest that the miR-200b-ZEB1 circuit is a master regulator of diverse stemness of HCC, which differentiates HCCs into those containing CD13+ /CD24+ CSCs from those containing EpCAM+ CSCs.
Assuntos
Carcinoma Hepatocelular/metabolismo , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Antígenos de Diferenciação/metabolismo , Antígenos CD13/metabolismo , Antígeno CD24/metabolismo , Carcinoma Hepatocelular/genética , Diferenciação Celular , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Metilação de DNA , DNA de Neoplasias/metabolismo , Regulação para Baixo , Deleção de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Células-Tronco Neoplásicas/microbiologia , Regiões Promotoras GenéticasRESUMO
Commensal Escherichia coli has been identified as a major protagonist of microbe-induced colorectal oncogenesis. Its tumour-promoting attribute is linked to the expression of DNA-damaging genotoxins. Using a constitutively invasive variant of non-pathogenic E. coli, we demonstrate that chronic presence of internalized E. coli leads to enhanced oncogenicity in colon cancer cells. Instead of genomic damage, the tumorigenic effect is mediated through an expansion of the cancer stem cell (CSC) population, likely through dedifferentiation of lineage-committed intestinal epithelial cells. Stemness-linked intestinal tumorigenicity is directly correlated to absence of microbial virulence factor expression and is specific for intestinal cells. The enriched CSC fraction remains stable in the absence of the instigating bacteria and can foster stemness traits in unexposed cells through secreted factors. Mechanistically, aberrant host invasion leads to realignment of multiple host signal transduction cascades, notably mutually re-enforcing NF-κB and ß-catenin activation, through reciprocal modulation of microbe sensing pathways Nod1/Rip2 and TLR/MyD88. The expanded tumorigenic CSC population is marked by enhanced malignancy traits, long-term self-renewal capacity and robust tumorigenic ability, both in vitro and in vivo. Our study shows that microbe-induced oncogenicity is not a strict correlate of commensal virulence and can be invoked by even non-pathogenic E. coli by engendering tumorigenic stemness in host cells.
Assuntos
Carcinogênese/metabolismo , Escherichia coli/patogenicidade , Intestinos/microbiologia , Intestinos/patologia , Células-Tronco Neoplásicas/microbiologia , Células-Tronco Neoplásicas/patologia , Animais , Células CACO-2 , Carcinogênese/patologia , Linhagem Celular Tumoral , Colo/metabolismo , Colo/microbiologia , Colo/patologia , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Células HCT116 , Células HT29 , Células Hep G2 , Humanos , Mucosa Intestinal/metabolismo , Masculino , Camundongos , Camundongos Nus , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteína Adaptadora de Sinalização NOD1/metabolismo , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Transdução de Sinais/fisiologia , beta Catenina/metabolismoRESUMO
Colorectal cancer (CRC) is a leading cause of cancer death and archetype for cancer as a genetic disease. However, the mechanisms for genetic change and their interactions with environmental risk factors have been difficult to unravel. New hypotheses, models, and methods are being used to investigate a complex web of risk factors that includes the intestinal microbiome. Recent research has clarified how the microbiome can generate genomic change in CRC. Several phenotypes among a small group of selected commensals have helped us better understand how mutations and chromosomal instability (CIN) are induced in CRC (e.g., toxin production, metabolite formation, radical generation, and immune modulation leading to a bystander effect). This review discusses recent hypotheses, models, and mechanisms by which the intestinal microbiome contributes to the initiation and progression of sporadic and colitis-associated forms of CRC. Overall, it appears the microbiome can initiate and/or promote CRC at all stages of tumorigenesis by acting as an inducer of DNA damage and CIN, regulating cell growth and death, generating epigenetic changes, and modulating host immune responses. Understanding how the microbiome interacts with other risk factors to define colorectal carcinogenesis will ultimately lead to more accurate risk prediction. A deeper understanding of CRC etiology will also help identify new targets for prevention and treatment and help accelerate the decline in mortality for this common cancer.
Assuntos
Neoplasias Colorretais/microbiologia , Microbioma Gastrointestinal/imunologia , Animais , Transformação Celular Neoplásica/imunologia , Instabilidade Cromossômica , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Dano ao DNA , Enterobacteriaceae/imunologia , Enterobacteriaceae/fisiologia , Transição Epitelial-Mesenquimal , Humanos , Células-Tronco Neoplásicas/microbiologia , Fatores de RiscoRESUMO
Helicobacter pylori infection is responsible for gastric carcinogenesis but host factors are also implicated. IQGAP1, a scaffolding protein of the adherens junctions interacting with E-cadherin, regulates cellular plasticity and proliferation. In mice, IQGAP1 deficiency leads to gastric hyperplasia. The aim of this study was to elucidate the consequences of IQGAP1 deletion on H. pylori-induced gastric carcinogenesis.Transgenic mice deleted for iqgap1 and WT littermates were infected with Helicobacter sp., and histopathological analyses of the gastric mucosa were performed. IQGAP1 and E-cadherin expression was evaluated in gastric tissues and in gastric epithelial cell lines in response to H. pylori infection. The consequences of IQGAP1 deletion on gastric epithelial cell behaviour and on the acquisition of cancer stem cell (CSC)-like properties were evaluated. After one year of infection, iqgap1+/- mice developed more preneoplastic lesions and up to 8 times more gastro-intestinal neoplasia (GIN) than WT littermates. H. pylori infection induced IQGAP1 and E-cadherin delocalization from cell-cell junctions. In vitro, knock-down of IQGAP1 favoured the acquisition of a mesenchymal phenotype and CSC-like properties induced by H. pylori infection.Our results indicate that alterations in IQGAP1 signalling promote the emergence of CSCs and gastric adenocarcinoma development in the context of an H. pylori infection.
Assuntos
Adenocarcinoma/microbiologia , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Células-Tronco Neoplásicas/microbiologia , Lesões Pré-Cancerosas/microbiologia , Neoplasias Gástricas/microbiologia , Proteínas Ativadoras de ras GTPase/deficiência , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Caderinas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal , Feminino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Predisposição Genética para Doença , Infecções por Helicobacter/genética , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/patologia , Interações Hospedeiro-Patógeno , Receptores de Hialuronatos/metabolismo , Hiperplasia , Camundongos da Linhagem 129 , Camundongos Knockout , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Fatores de Tempo , Proteínas Ativadoras de ras GTPase/genéticaRESUMO
Helicobacter pylori (H. pylori) infection is considered a major risk factor for gastric cancer. CagA behaves as a major bacterial oncoprotein playing a key role in H. pylori-induced tumorigenesis. Cancer stem cells (CSCs) are believed to possess the ability to initiate tumorigenesis and promote progression. Although studies have suggested that cancer cells can exhibit CSC-like properties in the tumor microenvironment, it remains unclear whether H. pylori infection could induce the emergence of CSC-like properties in gastric cancer cells and, the underlying mechanism. Here, gastric cancer cells were co-cultured with a CagA-positive H. pylori strain or a CagA isogenic mutant strain. We found that H. pylori-infected gastric cancer cells exhibited CSC-like properties, including an increased expression of CSC specific surface markers CD44 and Lgr5, as well as that of Nanog, Oct4 and c-myc, which are known pluripotency genes, and an increased capacity for self-renewal, whereas these properties were not observed in the CagA isogenic mutant strain-infected cells. Further studies revealed that H. pylori activated Wnt/ß-catenin signaling pathway in a CagA-dependent manner and that the activation of this pathway was dependent upon CagA-positive H. pylori-mediated phosphorylation of ß-catenin at the C-terminal Ser675 and Ser552 residues in a c-met- and/or Akt-dependent manner. We further demonstrated that this activation was responsible for H. pylori-induced CSC-like properties. Moreover, we found the promoter activity of Nanog and Oct4 were upregulated, and ß-catenin was observed to bind to these promoters during H. pylori infection, while a Wnt/ß-catenin inhibitor suppressed promoter activity and binding. Taken together, these results suggest that H. pylori upregulates Nanog and Oct4 via Wnt/ß-catenin signaling pathway to promote CSC-like properties in gastric cancer cells.
Assuntos
Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , Proteínas de Homeodomínio/metabolismo , Células-Tronco Neoplásicas/microbiologia , Fator 3 de Transcrição de Octâmero/metabolismo , Neoplasias Gástricas/microbiologia , Via de Sinalização Wnt , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Infecções por Helicobacter/genética , Infecções por Helicobacter/patologia , Humanos , Proteína Homeobox Nanog , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Regiões Promotoras Genéticas , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Ativação Transcricional , Regulação para Cima , beta Catenina/metabolismoRESUMO
Cancer cell lines can be useful to model cancer stem cells. Infection with Mycoplasma species is an insidious problem in mammalian cell culture. While investigating stem-like properties in early passage melanoma cell lines, we noted poorly reproducible results from an aliquot of a cell line that was later found to be infected with Mycoplasma hyorhinis. Deliberate infection of other early passage melanoma cell lines aliquots induced variable and unpredictable effects on expression of putative cancer stem cell markers, clonogenicity, proliferation and global gene expression. Cell lines established in stem cell media (SCM) were equally susceptible. Mycoplasma status is rarely reported in publications using cultured cells to study the cancer stem cell hypothesis. Our work highlights the importance of surveillance for Mycoplasma infection while using any cultured cells to interrogate tumor heterogeneity.
Assuntos
Regulação Neoplásica da Expressão Gênica , Mycoplasma hyorhinis/isolamento & purificação , Proteínas de Neoplasias/genética , Células-Tronco Neoplásicas/microbiologia , RNA Ribossômico 16S/isolamento & purificação , Técnicas de Tipagem Bacteriana , Técnicas de Cultura de Células/normas , Linhagem Celular Tumoral , Interações Hospedeiro-Patógeno , Humanos , Melanoma/genética , Melanoma/metabolismo , Melanoma/microbiologia , Melanoma/patologia , Mycoplasma hyorhinis/genética , Proteínas de Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Reação em Cadeia da Polimerase , Cultura Primária de Células , Controle de Qualidade , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/microbiologia , Neoplasias Cutâneas/patologiaRESUMO
Gastric cancer is still a leading cause of cancer-related mortality worldwide in spite of declining incidence. Gastric cancers are, essentially, adenocarcinomas and one of the strongest risk factors is still infection with Helicobacter pylori. Within the last years, it became clear that gastric self-renewal and carcinogenesis are intimately linked, particularly during chronic inflammatory conditions. Generally, gastric cancer is now regarded as a disease resulting from dysregulated differentiation of stem and progenitor cells, mainly due to an inflammatory environment. However, the situation in the stomach is rather complex, consisting of two types of gastric units which show bidirectional self-renewal from an unexpectedly large variety of progenitor/stem cell populations. As in many other tumors, cancer stem cells have also been characterized for gastric cancer. This review focuses on the various gastric epithelial stem cells, how they contribute to self-renewal and which routes are known to gastric adenocarcinomas, including their stem cells.
Assuntos
Adenocarcinoma/patologia , Mucosa Gástrica/patologia , Células-Tronco Neoplásicas/patologia , Neoplasias Gástricas/patologia , Estômago/patologia , Adenocarcinoma/microbiologia , Animais , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/isolamento & purificação , Humanos , Células-Tronco Neoplásicas/microbiologia , Estômago/microbiologia , Neoplasias Gástricas/microbiologiaRESUMO
Periodontitis is the most common chronic inflammatory condition occurring in the human oral cavity, but our knowledge on its contribution to oral cancer is rather limited. To define crosstalk between chronic periodontitis and oral cancer, we investigated whether Porphyromonas gingivalis, a major pathogen of chronic periodontitis, plays a role in oral cancer progression. To mimic chronic irritation by P. gingivalis in the oral cavity, oral squamous cell carcinoma (OSCC) cells were infected with P. gingivalis twice a week for 5 weeks. Repeated infection of oral cancer cells by P. gingivalis resulted in morphological changes of host cancer cells into an elongated shape, along with the decreased expression of epithelial cell markers, suggesting acquisition of an epithelial-to-mesenchymal transition (EMT) phenotype. The prolonged exposure to P. gingivalis also promoted migratory and invasive properties of OSCC cells and provided resistance against a chemotherapeutic agent, all of which are described as cellular characteristics undergoing EMT. Importantly, long-term infection by P. gingivalis induced an increase in the expression level of CD44 and CD133, well-known cancer stem cell markers, and promoted the tumorigenic properties of infected cancer cells compared to non-infected controls. Furthermore, increased invasiveness of P. gingivalis-infected OSCC cells was correlated with enhanced production of matrix metalloproteinase (MMP)-1 and MMP-10 that was stimulated by interleukin-8 (IL-8) release. This is the first report demonstrating that P. gingivalis can increase the aggressiveness of oral cancer cells via epithelial-mesenchymal transition-like changes and the acquisition of stemness, implicating P. gingivalis as a potential bacterial risk modifier.
Assuntos
Neoplasias Bucais/patologia , Células-Tronco Neoplásicas/patologia , Periodontite/patologia , Porphyromonas gingivalis/patogenicidade , Carcinoma de Células Escamosas , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-8/metabolismo , Metaloproteinase 1 da Matriz/biossíntese , Neoplasias Bucais/complicações , Neoplasias Bucais/microbiologia , Células-Tronco Neoplásicas/microbiologia , Periodontite/complicações , Periodontite/microbiologiaRESUMO
Gastric cancer (GC) is one of the leading causes of cancer-related mortality worldwide. Cancer stem cells (CSCs), which were first identified in acute myeloid leukemia and subsequently in a large array of solid tumors, play important roles in cancer initiation, dissemination and recurrence. CSCs are often transformed tissue-specific stem cells or de-differentiated transit amplifying progenitor cells. Several populations of multipotent gastric stem cells (GSCs) that reside in the stomach have been determined to regulate physiological tissue renewal and injury repair. These populations include the Villin+ and Lgr5+ GSCs in the antrum, the Troy+ chief cells in the corpus, and the Sox2+ GSCs that are found in both the antrum and the corpus. The disruption of tumor suppressors in Villin+ or Lgr5+ GSCs leads to GC in mouse models. In addition to residing GSCs, bone marrow-derived cells can initiate GC in a mouse model of chronic Helicobacter infection. Furthermore, expression of the cell surface markers CD133 or CD44 defines gastric CSCs in mouse models and in human primary GC tissues and cell lines. Targeted elimination of CSCs effectively reduces tumor size and grade in mouse models. In summary, the recent identification of normal GSCs and gastric CSCs has greatly improved our understanding of the molecular and cellular etiology of GC and will aid in the development of effective therapies to treat patients.
Assuntos
Células-Tronco Multipotentes/patologia , Células-Tronco Neoplásicas/patologia , Neoplasias Gástricas/patologia , Animais , Antígenos CD , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Caderinas/genética , Caderinas/metabolismo , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Transição Epitelial-Mesenquimal , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Humanos , Células-Tronco Multipotentes/metabolismo , Células-Tronco Multipotentes/microbiologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/microbiologia , Fenótipo , Fatores de Risco , Transdução de Sinais , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/terapiaRESUMO
The cancer stem cell hypothesis is an appealing concept to account for intratumoral heterogeneity and the observation that systemic metastasis and treatment failure are often associated with the survival of a small number of cancer cells. Whilst in vivo evidence forms the foundation of this concept, in vitro methods and reagents are attractive as they offer opportunities to perform experiments that are not possible in an animal model. While there is abundant evidence that existing cancer cell lines are not reliable models of tumor heterogeneity, recent advances based on well validated novel cancer cell lines established de novo in defined serum-free media are encouraging, particularly in the study of glioblastoma multiforme. In this chapter we wish to broadly outline the process of establishing, characterizing, and managing novel cancer cell lines in defined serum-free media, and discuss the limitations and potential opportunities that may arise from these model systems.
Assuntos
Separação Celular/métodos , Células-Tronco Neoplásicas/patologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Humanos , Mycoplasma/isolamento & purificação , Células-Tronco Neoplásicas/microbiologia , Manejo de EspécimesRESUMO
Systemic administration of Salmonella to tumor-bearing mice leads to the preferential accumulation within tumor sites and retardation of tumor growth. The cancer stem-like cell (CSC) hypothesis suggests that CSCs are the root of cancer and induce metastasis and recurrence. The objective of this study was to examine if Salmonella could inhibit the growth of CSCs derived from mouse breast cancer. Systemically injected Salmonella preferentially accumulated within tumors for at least three weeks and the bacteria accumulated preferentially not only in subcutaneous but also in orthotopic tumors over livers and spleens at ratios ranging from 1000:1 to 10,000:1. Salmonella were capable of delaying tumor growth and enhancing survival in both subcutaneous and orthotopic tumor models. More strikingly, Salmonella acted to retard tumor growth and extensively prolong the survival time of the mice bearing CSC-induced tumors. Our results also found that Salmonella predominantly, although not exclusively, resided in the CSC regions of the tumor. These data suggest that Salmonella can inhibit the growth of breast cancer by targeting the CSC niche. In conclusion, Salmonella can be used for the management of breast cancer.
Assuntos
Neoplasias da Mama/patologia , Células-Tronco Neoplásicas/microbiologia , Células-Tronco Neoplásicas/patologia , Salmonella , Animais , Linhagem Celular Tumoral , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Nicho de Células-Tronco , Transplante HeterólogoAssuntos
Infecções por Bacteroides/complicações , Bacteroides fragilis , Transformação Celular Neoplásica/metabolismo , Colite/microbiologia , Neoplasias do Colo/microbiologia , Mucosa Intestinal/microbiologia , Metaloendopeptidases/toxicidade , Células-Tronco Neoplásicas/microbiologia , Antibacterianos/farmacologia , Vacinas Bacterianas/farmacologia , Infecções por Bacteroides/tratamento farmacológico , Infecções por Bacteroides/prevenção & controle , Colite/metabolismo , Colite/patologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/prevenção & controle , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Metaloendopeptidases/efeitos dos fármacos , Células-Tronco Neoplásicas/patologiaRESUMO
Epigenetic changes correspond to heritable modifications of the chromatin structure, which do not involve any alteration of the DNA sequence but nonetheless affect gene expression. These mechanisms play an important role in cell differentiation, but aberrant occurrences are also associated with a number of diseases, including cancer and neural development disorders. In particular, aberrant DNA methylation induced by H. Pylori has been found to be a significant risk factor in gastric cancer. To investigate the sensitivity of different genes and cell types to this infection, a computational model of methylation in gastric crypts is developed. In this article, we review existing results from physical experiments and outline their limitations, before presenting the computational model and investigating the influence of its parameters.
Assuntos
Metilação de DNA , Infecções por Helicobacter/complicações , Modelos Genéticos , Neoplasias Gástricas/genética , Simulação por Computador , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Helicobacter pylori/fisiologia , Interações Hospedeiro-Patógeno , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/microbiologia , Neoplasias Gástricas/complicações , Neoplasias Gástricas/patologiaRESUMO
Until the last century, infectious diseases were the leading cause of human mortality. Therefore, our current medical reasoning is profoundly influenced by views that originated from medical microbiology. The notion that cancer growth is sustained by a sub-population of particular cells, the cancer stem cells, is highly reminiscent of the germ theory of disease as exemplified by Koch's postulates in the XIXth century. However, accumulating data underscore the importance of cell-cell interactions and tumor environment. Hence it is essential to critically review the basic tenets of the cancer stem cell concept on the light of their relationships with Koch's postulates. Shifting the pathogenic element from a special cellular entity (cancer stem cell or microorganism) to a "pathogenic field" could be critical for curing both cancer and drug-resistant infectious diseases.