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Cancer incidence escalates exponentially with advancing age; however, the underlying mechanism remains unclear. In this study, we build a chronological molecular clock at single-cell transcription level with a mammary stem cell-enriched population to depict physiological aging dynamics in female mice. We find that the mammary aging process is asynchronous and progressive, initiated by an early senescence program, succeeded by an entropic late senescence program with elevated cancer associated pathways, vulnerable to cancer predisposition. The transition towards senescence program is governed by a stem cell factor Bcl11b, loss of which accelerates mammary ageing with enhanced DMBA-induced tumor formation. We have identified a drug TPCA-1 that can rejuvenate mammary cells and significantly reduce aging-related cancer incidence. Our findings establish a molecular portrait of progressive mammary cell aging and elucidate the transcriptional regulatory network bridging mammary aging and cancer predisposition, which has potential implications for the management of cancer prevalence in the aged.
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Envelhecimento , Neoplasias da Mama , Senescência Celular , Feminino , Animais , Camundongos , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/genética , Humanos , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/metabolismo , Células-Tronco/metabolismoRESUMO
The intestine is prone to radiation damage in patients undergoing radiotherapy for pelvic tumors. However, there are currently no effective drugs available for the prevention or treatment of radiation-induced enteropathy (RIE). In this study, we aimed at investigating the impact of indole-3-carboxaldehyde (I3A) derived from the intestinal microbiota on RIE. Intestinal organoids were isolated and cultivated for screening radioprotective tryptophan metabolites. A RIE model was established using 13 Gy whole-abdominal irradiation in male C57BL/6J mice. After oral administration of I3A, its radioprotective ability was assessed through the observation of survival rates, clinical scores, and pathological analysis. Intestinal stem cell survival and changes in the intestinal barrier were observed through immunofluorescence and immunohistochemistry. Subsequently, the radioprotective mechanisms of I3A was investigated through 16S rRNA and transcriptome sequencing, respectively. Finally, human colon cancer cells and organoids were cultured to assess the influence of I3A on tumor radiotherapy. I3A exhibited the most potent radioprotective effect on intestinal organoids. Oral administration of I3A treatment significantly increased the survival rate in irradiated mice, improved clinical and histological scores, mitigated mucosal damage, enhanced the proliferation and differentiation of Lgr5+ intestinal stem cells, and maintained intestinal barrier integrity. Furthermore, I3A enhanced the abundance of probiotics, and activated the AhR/IL-10/Wnt signaling pathway to promote intestinal epithelial proliferation. As a crucial tryptophan metabolite, I3A promotes intestinal epithelial cell proliferation through the AhR/IL-10/Wnt signaling pathway and upregulates the abundance of probiotics to treat RIE. Microbiota-derived I3A demonstrates potential clinical application value for the treatment of RIE.
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Microbioma Gastrointestinal , Indóis , Camundongos Endogâmicos C57BL , Probióticos , Receptores de Hidrocarboneto Arílico , Via de Sinalização Wnt , Animais , Camundongos , Microbioma Gastrointestinal/efeitos dos fármacos , Masculino , Humanos , Probióticos/administração & dosagem , Probióticos/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Indóis/metabolismo , Indóis/farmacologia , Protetores contra Radiação/farmacologia , Organoides/metabolismo , Lesões por Radiação/metabolismo , Lesões por Radiação/prevenção & controle , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/efeitos da radiação , Intestinos/microbiologia , Intestinos/efeitos da radiação , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genéticaRESUMO
PURPOSE: Radiation-induced intestinal injury (RIII) commonly occur during abdominal-pelvic cancer radiation therapy; however, no effective prophylactic or therapeutic agents are available to manage RIII currently. This study aimed to clarify the potential of probiotic consortium supplementation in alleviating RIII. METHODS AND MATERIALS: Male C57BL/6J mice were orally administered a probiotic mixture comprising Bifidobacterium longum BL21, Lactobacillus paracasei LC86, and Lactobacillus plantarum Lp90 for 30 days before exposure to 13 Gy of whole abdominal irradiation. The survival rates, clinical scores, and histologic changes in the intestines of mice were assessed. The impacts of probiotic consortium treatment on intestinal stem cell proliferation, differentiation, and epithelial barrier function; oxidative stress; and inflammatory cytokines were evaluated. A comprehensive examination of the gut microbiota composition was conducted through 16S rRNA sequencing, while changes in metabolites were identified using liquid chromatography-mass spectrometry. RESULTS: The probiotic consortium alleviated RIII, as reflected by increased survival rates, improved clinical scores, and mitigated mucosal injury. The probiotic consortium treatment exhibited enhanced therapeutic effects at the histologic level compared with individual probiotic strains, although there was no corresponding improvement in survival rates and colon length. Moreover, the probiotic consortium stimulated intestinal stem cell proliferation and differentiation, enhanced the integrity of the intestinal epithelial barrier, and regulated redox imbalance and inflammatory responses in irradiated mice. Notably, the treatment induced a restructuring of the gut microbiota composition, particularly enriching short-chain fatty acid-producing bacteria. Metabolomic analysis revealed distinctive metabolic changes associated with the probiotic consortium, including elevated levels of anti-inflammatory and antiradiation metabolites. CONCLUSIONS: The probiotic consortium attenuated RIII by modulating the gut microbiota and metabolites, improving inflammatory symptoms, and regulating oxidative stress. These findings provide new insights into the maintenance of intestinal health with probiotic consortium supplementation and will facilitate the development of probiotic-based therapeutic strategies for RIII in clinical practice.
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Microbioma Gastrointestinal , Homeostase , Mucosa Intestinal , Camundongos Endogâmicos C57BL , Probióticos , Animais , Probióticos/farmacologia , Probióticos/uso terapêutico , Masculino , Camundongos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos da radiação , Mucosa Intestinal/patologia , Microbioma Gastrointestinal/efeitos dos fármacos , Lesões por Radiação/prevenção & controle , Lesões por Radiação/patologia , Proliferação de Células/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Intestinos/microbiologia , Diferenciação Celular/efeitos dos fármacos , Lesões Experimentais por Radiação/prevenção & controle , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/metabolismo , Células-Tronco , Citocinas/metabolismoRESUMO
The small intestine exhibits remarkable sensitivity to ionizing radiation (IR), which significantly hampers the effectiveness of radiotherapy in the treatment of abdominal and pelvic tumors. Unfortunately, no effective medications are available to treat radiation-induced intestinal damage (RIID). Fraxin (7-hydroxy-6-methoxycoumarin 8-glucoside), is a coumarin derivative extracted from the Chinese herb Cortex Fraxini. Several studies have underscored the anti-inflammatory, antibacterial, antioxidant, and immunomodulatory properties of fraxin. However, the efficacy of fraxin at preventing or mitigating RIID remains unclear. Thus, the present study aimed to investigate the protective effects of fraxin against RIID in vitro and in vivo and to elucidate the underlying mechanisms. The study findings revealed that fraxin markedly ameliorated intestinal injuries induced by 13 Gy whole abdominal irradiation (WAI), which was accompanied by a significant increase in the population of Lgr5+ intestinal stem cells (ISCs) and Ki67+ progeny. Furthermore, fraxin mitigated WAI-induced intestinal barrier damage, and reduced oxidative stress and intestinal inflammation in mice. Transcriptome sequencing of fraxin-treated mice revealed upregulation of IL-22, a pleiotropic cytokine involved in regulating the function of intestinal epithelial cells. Moreover, in both human intestinal epithelial cells and ex vivo cultured mouse intestinal organoids, fraxin effectively ameliorated IR-induced damage by promoting the expression of IL-22. The radioprotective effects of fraxin were partially negated in the presence of an IL-22-neutralizing antibody. In summary, fraxin is demonstrated to possess the ability to alleviate RIID and maintain intestinal homeostasis, suggesting that fraxin might serve as a strategy for mitigating accidental radiation exposure- or radiotherapy-induced RIID.
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Cumarínicos , Intestinos , Camundongos , Humanos , Animais , Cumarínicos/farmacologia , Cumarínicos/uso terapêutico , Antioxidantes , Radiação IonizanteRESUMO
Transient elastography (TE), recommended by the WHO, is an established method for characterizing liver fibrosis via liver stiffness measurement (LSM). However, technical barriers remain towards point-of-care application, as conventional TE requires wired connections, possesses a bulky size, and lacks adequate imaging guidance for precise liver localization. In this work, we report the design, phantom validation, and clinical evaluation of a palm-sized TE system that enables simultaneous B-mode imaging and LSM. The performance of this system was validated experimentally using tissue-equivalent reference phantoms (1.45-75 kPa). Comparative studies against other liver elastography techniques, including conventional TE and two-dimensional shear wave elastography (2D-SWE), were performed to evaluate its reliability and validity in adults with various chronic liver diseases. Intra- and inter-operator reliability of LSM were established by an elastography expert and a novice. A good agreement was observed between the Young's modulus reported by the phantom manufacturer and this system (bias: 1.1-8.6%). Among 121 patients, liver stiffness measured by this system and conventional TE were highly correlated (r = 0.975) and strongly agreed with each other (mean difference: -0.77 kPa). Inter-correlation of this system with conventional TE and 2D-SWE was observed. Excellent-to-good operator reliability was demonstrated in 60 patients (ICCs: 0.824-0.913). We demonstrated the feasibility of employing a fully integrated phased array probe for reliable and valid LSM, guided by real-time B-mode imaging of liver anatomy. This system represents the first technical advancement toward point-of-care liver fibrosis assessment. Its small footprint, along with B-mode guidance capability, improves examination efficiency and scales up screening for liver fibrosis.
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Organoid culture has been extensively exploited for normal tissue reconstruction and disease modeling. However, it is still challenging to establish organoids that mimic in vivo-like architecture, size and function under homeostatic conditions. Here we describe the development of a long-term adult stem cell-derived mammary mini gland culture system that supports robust three-dimensional outgrowths recapitulating the morphology, scale, cellular context and transcriptional heterogeneity of the normal mammary gland. The self-organization ability of stem cells and the stability of the outgrowths were determined by a coordinated combination of extracellular matrix, environmental signals and dynamic physiological cycles. We show that these mini glands were hormone responsive and could recapitulate the entire postnatal mammary development including puberty, estrus cycle, lactation and involution. We also observed that these mini glands maintained the presence of mammary stem cells and could also recapitulate the fate transition from embryonic bipotency to postnatal unipotency in lineage tracing assays. In addition, upon induction of oncogene expression in the mini glands, we observed tumor initiation in vitro and in vivo in a mouse model. Together, this study provides an experimental system that can support a dynamic miniature mammary gland for the study of physiologically relevant, complex biological processes.
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Glândulas Mamárias Animais , Células-Tronco , Camundongos , Feminino , Animais , Glândulas Mamárias Animais/metabolismo , Carcinogênese , Células EpiteliaisRESUMO
The BRCA1/BARD1 complex plays a key role in the repair of DNA double-strand breaks (DSBs) in both somatic cells and germ cells. However, the underlying molecular mechanism by which this complex mediates DSB repair is not fully understood. Here, we examined the XY body of male germ cells, where DSBs are accumulated. We show that the recruitment of the BRCA1/BARD1 complex to the unsynapsed axis of the XY body is mediated by pre-ribosomal RNA (pre-rRNA). Similarly, the BRCA1/BARD1 complex associates with pre-rRNA in somatic cells, which not only forms nuclear foci in response to DSBs, but also targets the BRCA1/BARD1 complex to DSBs. The interactions between the BRCT domains of the BRCA1/BARD1 complex and pre-rRNA induce liquid-liquid phase separations, which may be the molecular basis of DSB-induced nuclear foci formation of the BRCA1/BARD1 complex. Moreover, cancer-associated mutations in the BRCT domains of BRCA1 and BARD1 abolish their interactions with pre-rRNA. Pre-rRNA also mediates BRCA1-dependent homologous recombination, and suppression of pre-rRNA biogenesis sensitizes cells to PARP inhibitor treatment. Collectively, this study reveals that pre-rRNA is a functional partner of the BRCA1/BARD1 complex in the DSB repair.
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Cardiac hypertrophy, a kind of cardiomyopathic abnormality, might trigger heart contractile and diastolic dysfunction, and even heart failure. Currently, bisphenols (BPs) including bisphenol A (BPA), and its alternatives bisphenol AF (BPAF), bisphenol F (BPF) and bisphenol S (BPS) are ubiquitously applied in various products and potentially possess high cardiovascular risks for humans. However, the substantial experimental evidences of BPs on heart function, and their structure-related effects on cardiomyocyte hypertrophy are still urgently needed. DNA methylation, a typical epigenetics, play key roles in BPs-induced transcription dysregulation, thereby affecting human health including cardiovascular system. Thus, in this study, we performed RNA-seq and reduced representation bisulfite sequencing (RRBS) to profile the landscapes of BPs-induced cardiotoxicity and to determine the key roles of DNA methylation in the transcription. Further, the capabilities of three BPA analogues, together with BPA, in impacting heart function and changing DNA methylation and transcription were compared. We concluded that similar to BPA, BPAF, BPF and BPS exposure deteriorated heart function in a mouse model, and induced cardiomyocyte hypertrophy in a H9c2 cell line. BPAF, BPF and BPS all played BPA-like roles in both transcriptive and methylated hierarchies. Moreover, we validated the expression levels of four cardiomyocyte hypertrophy related candidate genes, Psmc1, Piptnm2, Maz and Dusp18, which were all upregulated and with DNA hypomethylation. The findings on the induction of BPA analogues on cardiomyocyte hypertrophy and DNA methylation revealed their potential detrimental risks in heart function of humans.
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Epigênese Genética , Epigenoma , Humanos , Animais , Camundongos , Transcriptoma , Miócitos Cardíacos , HipertrofiaRESUMO
Survival from extranodal nasal-type NK/T-cell lymphoma (ENKTCL) has substantially improved over the last decade. However, there is little consensus as to whether a population of patients with ENKTCL can be considered "cured" of the disease. We aimed to evaluate the statistical "cure" of ENKTCL in the modern treatment era. This retrospective multicentric study reviewed the clinical data of 1,955 patients with ENKTCL treated with non-anthracycline-based chemotherapy and/or radiotherapy in the China Lymphoma Collaborative Group multicenter database between 2008 and 2016. A non-mixture cure model with incorporation of background mortality was fitted to estimate cure fractions, median survival times and cure time points. The relative survival curves attained plateau for the entire cohort and most subsets, indicating that the notion of cure was robust. The overall cure fraction was 71.9%. The median survival was 1.1 years in uncured patients. The cure time was 4.5 years, indicating that beyond this time, mortality in ENKTCL patients was statistically equivalent to that in the general population. Cure probability was associated with B symptoms, stage, performance status, lactate dehydrogenase, primary tumor invasion, and primary upper aerodigestive tract site. Elderly patients (>60 years) had a similar cure fraction to that of younger patients. The 5-year overall survival rate correlated well with the cure fraction across risk-stratified groups. Thus, statistical cure is possible in ENKTCL patients receiving current treatment strategies. Overall probability of cure is favorable, though it is affected by the presence of risk factors. These findings have a high potential impact on clinical practice and patients' perspective.
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Linfoma Extranodal de Células T-NK , Humanos , Idoso , Prognóstico , Estudos Retrospectivos , Linfoma Extranodal de Células T-NK/diagnóstico , Linfoma Extranodal de Células T-NK/terapia , Fatores de Risco , Células Matadoras Naturais/patologiaRESUMO
Cancer metastasis is the leading cause of mortality in patients with cancer. Theories have been developed to explain the causes and principles of metastasis. Metastasis is attributed to cancer cell-intrinsic properties and the extrinsic cellular environment. In recent years, the intratumor microbiota has been identified as an integral tumor component and may functionally regulate various aspects of metastasis. These novel discoveries in intratumor microbiota reshape the framework of our understanding of metastasis and reveal a new path for studies on cancer progression and clinical cancer management. Here, we summarize recent advances in the emerging roles of intratumor microbiota in cancer metastasis and discuss the challenges and implications for cancer treatment.
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Microbiota , Neoplasias , Humanos , Neoplasias/microbiologia , Neoplasias/patologia , Metástase NeoplásicaRESUMO
Background: The immune system is well known to exert tumor immunosurveillance effects, and that immune cells circulating in the peripheral blood affect tumor prognosis. The study investigated the effect of estimated dose of radiation on circulating immune cells (EDRIC) and tumor control for esophageal cancer patients treated with concurrent chemo-radiotherapy. Materials and Methods: A total of 146 esophageal cancer patients treated with radiotherapy between January 2016 and June 2020 were retrospectively identified. We determined EDRIC, known prognostic factors, and the association of these factors with progression-free survival (PFS) and overall survival (OS). Results: The median follow-up was 17.9 months (2.7-60.4 months). The 3-year OS was 39.2%. Severe post-treatment lymphopenia was observed in 84.2% of patients. A negative correlation between EDRIC and absolute lymphocyte count was found (r = -0.679; p < 0.001). Patients with EDRIC ≥10.3 Gy were more likely to demonstrate grade 4 lymphopenia (55.2% vs. 4.5%; p < 0.001). Patients with grade 4 lymphopenia had a worse OS and PFS. On multivariate analysis, EDRIC was independently associated with OS (hazard ratio [HR], 1.142; p = 0.016) and PFS (HR, 1.121; p = 0.019). Conclusions: EDRIC can predict lymphocyte reduction and poor prognosis for esophageal cancer patients treated with radiotherapy.
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Neoplasias Esofágicas , Linfopenia , Humanos , Estudos Retrospectivos , Quimiorradioterapia/efeitos adversos , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/tratamento farmacológico , Prognóstico , Linfopenia/etiologia , Linfopenia/tratamento farmacológico , Doses de RadiaçãoRESUMO
Spatially resolved proteomics is an emerging approach for mapping proteome heterogeneity of biological samples, however, it remains technically challenging due to the complexity of the tissue microsampling techniques and mass spectrometry analysis of nanoscale specimen volumes. Here, we describe a spatially resolved proteomics method based on the combination of tissue expansion with mass spectrometry-based proteomics, which we call Expansion Proteomics (ProteomEx). ProteomEx enables quantitative profiling of the spatial variability of the proteome in mammalian tissues at ~160 µm lateral resolution, equivalent to the tissue volume of 0.61 nL, using manual microsampling without the need for custom or special equipment. We validated and demonstrated the utility of ProteomEx for streamlined large-scale proteomics profiling of biological tissues including brain, liver, and breast cancer. We further applied ProteomEx for identifying proteins associated with Alzheimer's disease in a mouse model by comparative proteomic analysis of brain subregions.
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Doença de Alzheimer , Proteômica , Animais , Camundongos , Proteoma , Expansão de Tecido , Espectrometria de Massas , MamíferosRESUMO
The tissue-resident microbiota is an integral component of multiple tumor types, but it remains challenging to characterize its abundance and composition due to its low biomass. Here, we describe an optimized protocol for quantification and profiling of tissue-resident microbiota. The major optimized steps include DNA extraction, qPCR, 16S library construction, and bioinformatics analysis. This protocol enables robust and accurate characterization of the dynamics of normal and tumor tissue-resident microbiota at its physiological abundance from both mouse and human origins. For complete details on the use and execution of this protocol, please refer to Fu et al. (2022).
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Microbiota , Neoplasias , Humanos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Biologia ComputacionalRESUMO
Intratumor microbiota is a dynamic cancer component that can be carried over by metastatic tumor cells to distal organs. This protocol was developed to genetically label Staphylococcus xylosus and trace the recombinant strain in vivo in the tumor. We optimized the recombination-based gene replacement protocol to insert a GFP-Erythromycin resistant protein (Erm) cassette. The inserted cassette facilitates the tracking of the recombinant strain, allowing a sensitive interrogation of microbial dynamics with high temporal and spatial resolution. For complete details on the use and execution of this protocol, please refer to Fu et al. (2022).
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Eritromicina , Staphylococcus , Staphylococcus/genética , Staphylococcus/metabolismo , Eritromicina/metabolismo , Proteínas/metabolismoRESUMO
The biosynthesis of unsaturated fatty acids is involved in the initiation and progression of colon adenocarcinoma (COAD). In this study, we aimed to investigate the multi-omics characteristics of unsaturated fatty acid biosynthesis-related genes and explore their prognostic value in colon cancer by analyzing the data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. An unsaturated fatty acid biosynthesis pathway related-genes enrichment score (BUFAS) was constructed utilizing the single sample gene set enrichment analysis (ssGSEA). We discovered that a high BUFAS was associated with longer overall survival (OS) in both the training and the validation sets. Multivariable analysis including the clinical characteristics further verified the independent prognostic value of the BUFAS in both the TCGA-COAD and the GSE39582 datasets. In addition, GSEA analysis revealed that BUFAS was positively associated with several signaling pathways, including MTORC1, peroxisome, and pathways related to fatty acid metabolism, while was negatively associated with other signaling pathways, such as hedgehog, NOTCH, and Wnt/beta-catenin pathway. Furthermore, in the COAD cell lines of the Genomics of Drug Sensitivity in Cancer (GDSC) database, we found that BUFAS was positively correlated with the drug sensitivities of cisplatin, gemcitabine, camptothecin, lapatinib, and afatinib, while was negatively correlated with that of ponatinib. Moreover, in the COAD single-cell transcriptomic dataset (GSE146771), the BUFAS varied among different cell types and was enriched in mast cells and fibroblasts. Taken together, the BUFAS we constructed could be used as an independent prognostic signature in predicting the OS and drug resistance of colon cancer. Unsaturated fatty acid biosynthesis pathway might serve as potential therapeutic targets for cancer treatment.
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Metastasis, the major cause of cancer death, represents one of the major challenges in oncology. Scientists are still trying to understand the biological basis underlying the dissemination and outgrowth of tumor cells, why these cells can remain dormant for years, how they become resistant to the immune system or cytotoxic effects of systemic therapy, and how they interact with their new microenvironment. We asked experts to discuss some of the unknowns, advances, and areas of opportunity related to cancer metastasis.
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Neoplasias , Microambiente Tumoral , Humanos , Sistema Imunitário/patologia , Metástase Neoplásica/patologia , Neoplasias/tratamento farmacológico , Neoplasias/patologiaRESUMO
By improving the previous method of CUT&RUN, we developed D-CUT&RUN (DSP fixed CUT&RUN) for under-expressed transcription factor. High-quality data could be obtained for low expressed transcription factors using chemical crosslinkers (DSP) and reducing agent (DTT). We applied our D-CUT&RUN to detection of Bcl11b and Mycn binding sites in mammary epithelial progenitor cells. Pathway enrichment analysis results of Bcl11b target genes showed that Bcl11b was a regulatory factor involved in breast cancer and it could negatively regulate Wnt signaling pathway. Furthermore, the role of Bcl11b in breast cancer was mediated by catabolic process and stress-related pathway. Our research suggested that D-CUT&RUN could be used for low abundance transcription factor binding sites detection and Bcl11b could be a target for breast cancer treatment in the future.
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Neoplasias da Mama , Fatores de Transcrição , Neoplasias da Mama/genética , Feminino , Humanos , Proteínas Repressoras/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Via de Sinalização WntRESUMO
Overexpression and/or overactivation of sphingosine kinase 1/2 (SphK1/2) is important for tumorigenesis and progression of cervical cancer. The current study examined the potential activity and signaling mechanisms of SKI-V, a non-lipid small molecule SphK inhibitor, against cervical cancer cells. In different primary and immortalized cervical cancer cells, SKI-V exerted significant anti-cancer activity by inhibiting cell viability, colony formation, proliferation, cell cycle progression and cell migration. Significant apoptosis activation was detected in SKI-V-treated cervical cancer cells. Significantly, SKI-V also provoked programmed necrosis cascade in cervical cancer cells, as it induced mitochondrial p53-cyclophilin-D-adenine nucleotide translocator-1 (ANT1) complexation, mitochondrial membrane potential collapse, reactive oxygen species production and the release of lactate dehydrogenase into the medium. Further, SKI-V blocked SphK activation and induced ceramide accumulation in primary cervical cancer cells, without affecting SphK1/2 expression. SKI-V-induced cytotoxicity in cervical cancer cells was largely inhibited by sphingosine-1-phosphate or the SphK1 activator K6PC-5, but was sensitized by adding the short-chain ceramide C6. Moreover, SKI-V inhibited Akt-mTOR (mammalian target of rapamycin) activation in primary cervical cancer cells, and its cytotoxicity was mitigated by a constitutively-active Akt. In vivo, daily intraperitoneal injection of SKI-V significantly inhibited subcutaneous primary cervical cancer xenograft growth in nude mice. Together, the SphK inhibitor SKI-V suppresses cervical cancer growth in vitro and in vivo.
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Antineoplásicos , Neoplasias do Colo do Útero , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Ceramidas/metabolismo , Feminino , Humanos , Mamíferos/metabolismo , Camundongos , Camundongos Nus , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológicoRESUMO
The high radiosensitivity of the intestinal epithelium limits the outcomes of radiotherapy against abdominal malignancies, which results in poor prognosis. Currently, no effective prophylactic or therapeutic strategy is available to mitigate radiation toxicity in the intestine. Our previous study revealed that the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) attenuates radiation-induced intestinal injury (RIII). The aim of the present study was to determine the effect of EGCG on the intestinal flora of irradiated mice. EGCG administration reduced radiation-induced intestinal mucosal injury, and significantly increased the number of Lgr5+ intestinal stem cells (ISCs) and Ki67+ crypt cells. In addition, EGCG reversed radiation-induced gut dysbiosis, restored the Firmicutes/Bacteroidetes ratio, and increased the abundance of beneficial bacteria. Our findings provide novel insight into EGCG-mediated remission of RIII, revealing that EGCG could be a potential modulator of gut microbiota to prevent and treat RIII.
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Tumor-resident intracellular microbiota is an emerging tumor component that has been documented for a variety of cancer types with unclear biological functions. Here, we explored the functional significance of these intratumor bacteria, primarily using a murine spontaneous breast-tumor model MMTV-PyMT. We found that depletion of intratumor bacteria significantly reduced lung metastasis without affecting primary tumor growth. During metastatic colonization, intratumor bacteria carried by circulating tumor cells promoted host-cell survival by enhancing resistance to fluid shear stress by reorganizing actin cytoskeleton. We further showed that intratumor administration of selected bacteria strains isolated from tumor-resident microbiota promoted metastasis in two murine tumor models with significantly different levels of metastasis potential. Our findings suggest that tumor-resident microbiota, albeit at low biomass, play an important role in promoting cancer metastasis, intervention of which might therefore be worth exploring for advancing oncology care.