Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
15,468
result(s) for
"Carcinogenesis - pathology"
Sort by:
Helicobacter pylori CagA promotes Snail-mediated epithelial–mesenchymal transition by reducing GSK-3 activity
2014
Cytotoxin-associated gene A (CagA) is an oncoprotein and a major virulence factor of
H. pylori
. CagA is delivered into gastric epithelial cells via a type IV secretion system and causes cellular transformation. The loss of epithelial adhesion that accompanies the epithelial–mesenchymal transition (EMT) is a hallmark of gastric cancer. Although CagA is a causal factor in gastric cancer, the link between CagA and the associated EMT has not been elucidated. Here, we show that CagA induces the EMT by stabilizing Snail, a transcriptional repressor of E-cadherin expression. Mechanistically we show that CagA binds GSK-3 in a manner similar to Axin and causes it to shift to an insoluble fraction, resulting in reduced GSK-3 activity. We also find that the level of Snail protein is increased in
H. pylori
infected epithelium in clinical samples. These results suggest that
H. pylori
CagA acts as a pathogenic scaffold protein that induces a Snail-mediated EMT via the depletion of GSK-3.
Gastric cancer is associated with
H. pylori
infection and these tumours frequently show features of epithelial–mesenchymal transition (EMT). Here, the authors show that the
H. pylori
virulence protein, CagA, reduces the activity of GSK3b, which leads to the stabilization of Snail, a protein that induces EMT.
Journal Article
Targeting the Notch-regulated non-coding RNA TUG1 for glioma treatment
2016
Targeting self-renewal is an important goal in cancer therapy and recent studies have focused on Notch signalling in the maintenance of stemness of glioma stem cells (GSCs). Understanding cancer-specific Notch regulation would improve specificity of targeting this pathway. In this study, we find that Notch1 activation in GSCs specifically induces expression of the lncRNA,
TUG1
.
TUG1
coordinately promotes self-renewal by sponging miR-145 in the cytoplasm and recruiting polycomb to repress differentiation genes by locus-specific methylation of histone H3K27 via YY1-binding activity in the nucleus. Furthermore, intravenous treatment with antisense oligonucleotides targeting
TUG1
coupled with a drug delivery system induces GSC differentiation and efficiently represses GSC growth
in vivo.
Our results highlight the importance of the Notch-lncRNA axis in regulating self-renewal of glioma cells and provide a strong rationale for targeting
TUG1
as a specific and potent therapeutic approach to eliminate the GSC population.
Self-renewal of cancer stem cells can contribute to glioma progression. Here, the authors show that Notch1 activation in glioma stem cells induces expression of the lncRNA
TUG1
, which promotes self-renewal through the repression of differentiation genes, and that targeting
TUG1
represses glioma growth
in vivo
.
Journal Article
A pilot study of the impact of Vitamin C supplementation with neoadjuvant chemoradiation on regulators of inflammation and carcinogenesis in esophageal cancer patients
by
Babar, Mawash
,
Abdel-Latif, Mohamed
,
Kelleher, Dermot
in
Adenocarcinoma
,
Adenocarcinoma - diagnostic imaging
,
Adenocarcinoma - pathology
2019
Aims: Vitamin C plays a role in chemoprevention in cancer treatment, and Vitamin C modulates many regulators of inflammation in in vitro studies. The aim of this study is to assess the effect of Vitamin C supplementation with neoadjuvant chemoradiation in esophageal adenocarcinoma on the nuclear factor-kappa B (NF-κB) and associated cytokines.
Materials and Methods: A total of 20 patients undergoing multimodal treatment for esophageal adenocarcinoma were randomized to receive Vitamin C (1000 mg/day) orally for 4 weeks or no supplementation. Pre- and post-Vitamin C endoscopic biopsies were used for the study of NF-κB activity and cytokine analysis.
Results: NF-κB activity along with cytokines was activated in the cancer tissue pretreatment. Down-regulation in NF-κB activity was observed in 25% of cases, two from the Vitamin C arm posttreatment. There was a significant reduction in cytokines levels in the cancer group, and this effect was more pronounced in the Vitamin C group (P < 0.05).
Conclusions: Vitamin C supplementation had a mild protective effect in modulating of regulators of inflammation and carcinogenesis. Further studies with larger numbers of endpoints are needed to evaluate its effect on modulation of chemoradiation responses.
Journal Article
Cancer‐associated upregulation of histone H3 lysine 9 trimethylation promotes cell motility in vitro and drives tumor formation in vivo
2013
Global histone modification patterns correlate with tumor phenotypes and prognostic factors in multiple tumor types. Recent studies suggest that aberrant histone modifications play an important role in cancer. However, the effects of global epigenetic rearrangements on cell functions remain poorly understood. In this study, we show that the histone H3 lysine 9 (H3K9) methyltransferase SUV39H1 is clearly involved in regulating cell migration in vitro. Overexpression of wild‐type SUV39H1, but not enzymatically inactive SUV39H1, activated migration in breast and colorectal cancer cells. Inversely, migration was reduced by knockdown of SUV39H1 or chemical inhibition by chaetocin. In addition, H3K9 trimethylation (H3K9me3) was specifically increased in invasive regions of colorectal cancer tissues. Moreover, the presence of H3K9me3 positively correlated with lymph node metastasis in colorectal cancer patients. Furthermore, overexpression of SUV39H1 drove tumorigenesis in mouse, resulting in a considerable decrease in survival rate. These data indicate that H3K9 trimethylation plays an important role in human colorectal cancer progression, possibly by promoting collective cell invasion.
Journal Article
Single-cell analysis of human primary prostate cancer reveals the heterogeneity of tumor-associated epithelial cell states
2022
Prostate cancer is the second most common malignancy in men worldwide and consists of a mixture of tumor and non-tumor cell types. To characterize the prostate cancer tumor microenvironment, we perform single-cell RNA-sequencing on prostate biopsies, prostatectomy specimens, and patient-derived organoids from localized prostate cancer patients. We uncover heterogeneous cellular states in prostate epithelial cells marked by high androgen signaling states that are enriched in prostate cancer and identify a population of tumor-associated club cells that may be associated with prostate carcinogenesis.
ERG
-negative tumor cells, compared to
ERG
-positive cells, demonstrate shared heterogeneity with surrounding luminal epithelial cells and appear to give rise to common tumor microenvironment responses. Finally, we show that prostate epithelial organoids harbor tumor-associated epithelial cell states and are enriched with distinct cell types and states from their parent tissues. Our results provide diagnostically relevant insights and advance our understanding of the cellular states associated with prostate carcinogenesis.
The changes that prostate cancer (PCa) induces in its microenvironment are not fully understood. Here the authors use single-cell RNA-seq and organoids to characterise how the microenvironment responds to PCa, and also identify tumour-associated epithelial cell states and club cells.
Journal Article
Diverging inflammasome signals in tumorigenesis and potential targeting
2019
Inflammasomes are molecular platforms that assemble upon sensing various intracellular stimuli. Inflammasome assembly leads to activation of caspase 1, thereby promoting the secretion of bioactive interleukin-1β (IL-1β) and IL-18 and inducing an inflammatory cell death called pyroptosis. Effectors of the inflammasome efficiently drive an immune response, primarily providing protection against microbial infections and mediating control over sterile insults. However, aberrant inflammasome signalling is associated with pathogenesis of inflammatory and metabolic diseases, neurodegeneration and malignancies. Chronic inflammation perpetuated by inflammasome activation plays a central role in all stages of tumorigenesis, including immunosuppression, proliferation, angiogenesis and metastasis. Conversely, inflammasome signalling also contributes to tumour suppression by maintaining intestinal barrier integrity, which portrays the diverse roles of inflammasomes in tumorigenesis. Studies have underscored the importance of environmental factors, such as diet and gut microbiota, in inflammasome signalling, which in turn influences tumorigenesis. In this Review, we deliver an overview of the interplay between inflammasomes and tumorigenesis and discuss their potential as therapeutic targets.Inflammasome signalling in myeloid cells protects against microbial infections. Aberrant inflammasome signalling promotes chronic inflammation, which contributes to tumorigenesis. This Review presents an overview of the diverging roles of inflammasomes in cancer and discusses its targeting potential in anticancer therapy.
Journal Article
Neutrophils in cancer carcinogenesis and metastasis
2021
In recent years, neutrophils have attracted increasing attention because of their cancer-promoting effects. An elevated neutrophil-to-lymphocyte ratio is considered a prognostic indicator for patients with cancer. Neutrophils are no longer regarded as innate immune cells with a single function, let alone bystanders in the pathological process of cancer. Their diversity and plasticity are being increasingly recognized. This review summarizes previous studies assessing the roles and mechanisms of neutrophils in cancer initiation, progression, metastasis and relapse. Although the findings are controversial, the fact that neutrophils play a dual role in promoting and suppressing cancer is undeniable. The plasticity of neutrophils allows them to adapt to different cancer microenvironments and exert different effects on cancer. Given the findings from our own research, we propose a reasonable hypothesis that neutrophils may be reprogrammed into a cancer-promoting state in the cancer microenvironment. This new perspective indicates that neutrophil reprogramming in the course of cancer treatment is a problem worthy of attention. Preventing or reversing the reprogramming of neutrophils may be a potential strategy for adjuvant cancer therapy.
Journal Article
RNA in cancer
2021
While the processing of mRNA is essential for gene expression, recent findings have highlighted that RNA processing is systematically altered in cancer. Mutations in RNA splicing factor genes and the shortening of 3′ untranslated regions are widely observed. Moreover, evidence is accumulating that other types of RNAs, including circular RNAs, can contribute to tumorigenesis. In this Review, we highlight how altered processing or activity of coding and non-coding RNAs contributes to cancer. We introduce the regulation of gene expression by coding and non-coding RNA and discuss both established roles (microRNAs and long non-coding RNAs) and emerging roles (selective mRNA processing and circular RNAs) for RNAs, highlighting the potential mechanisms by which these RNA subtypes contribute to cancer. The widespread alteration of coding and non-coding RNA demonstrates that altered RNA biogenesis contributes to multiple hallmarks of cancer.This Review discusses how altered processing or activity of coding and non-coding RNAs contributes to cancer, introducing the regulation of gene expression by coding and non-coding RNA and discussing both established and emerging roles for RNAs in cancer.
Journal Article
Immune evasion before tumour invasion in early lung squamous carcinogenesis
2019
Early detection and treatment are critical for improving the outcome of patients with cancer
1
. Understanding the largely uncharted biology of carcinogenesis requires deciphering molecular processes in premalignant lesions, and revealing the determinants of the intralesional immune reaction during cancer development. The adaptive immune response within tumours has previously been shown to be strongest at the earliest stage of carcinoma
2
,
3
. Here we show that immune activation and immune escape occur before tumour invasion, and reveal the relevant immune biomarkers of the pre-invasive stages of carcinogenesis in the lung. We used gene-expression profiling and multispectral imaging to analyse a dataset of 9 morphological stages of the development of lung squamous cell carcinoma, which includes 122 well-annotated biopsies from 77 patients. We identified evolutionary trajectories of cancer and immune pathways that comprise (1) a linear increase in proliferation and DNA repair from normal to cancerous tissue; (2) a transitory increase of metabolism and early immune sensing, through the activation of resident immune cells, in low-grade pre-invasive lesions; (3) the activation of immune responses and immune escape through immune checkpoints and suppressive interleukins from high-grade pre-invasive lesions; and, ultimately, (4) the activation of the epithelial–mesenchymal transition in the invasive stage of cancer. We propose that carcinogenesis in the lung involves a dynamic co-evolution of pre-invasive bronchial cells and the immune response. These findings highlight the need to develop immune biomarkers for early detection as well as immunotherapy-based chemopreventive approaches for individuals who are at high risk of developing lung cancer.
The immune response is modulated at a early stage of carcinogenesis, such that both immune activation and evasion precede tumour invasion.
Journal Article
Mucosal microbiome dysbiosis in gastric carcinogenesis
by
Nakatsu, Geicho
,
Coker, Olabisi Oluwabukola
,
Sung, Joseph J Y
in
Adult
,
Aged
,
Aged, 80 and over
2018
ObjectivesWe aimed to characterise the microbial changes associated with histological stages of gastric tumourigenesis.DesignWe performed 16S rRNA gene analysis of gastric mucosal samples from 81 cases including superficial gastritis (SG), atrophic gastritis (AG), intestinal metaplasia (IM) and gastric cancer (GC) from Xi’an, China, to determine mucosal microbiome dysbiosis across stages of GC. We validated the results in mucosal samples of 126 cases from Inner Mongolia, China.ResultsWe observed significant mucosa microbial dysbiosis in IM and GC subjects, with significant enrichment of 21 and depletion of 10 bacterial taxa in GC compared with SG (q<0.05). Microbial network analysis showed increasing correlation strengths among them with disease progression (p<0.001). Five GC-enriched bacterial taxa whose species identifications correspond to Peptostreptococcus stomatis, Streptococcus anginosus, Parvimonas micra, Slackia exigua and Dialister pneumosintes had significant centralities in the GC ecological network (p<0.05) and classified GC from SG with an area under the receiver-operating curve (AUC) of 0.82. Moreover, stronger interactions among gastric microbes were observed in Helicobacter pylori-negative samples compared with H. pylori-positive samples in SG and IM. The fold changes of selected bacteria, and strengths of their interactions were successfully validated in the Inner Mongolian cohort, in which the five bacterial markers distinguished GC from SG with an AUC of 0.81.ConclusionsIn addition to microbial compositional changes, we identified differences in bacterial interactions across stages of gastric carcinogenesis. The significant enrichments and network centralities suggest potentially important roles of P. stomatis, D. pneumosintes, S. exigua, P. micra and S. anginosus in GC progression.
Journal Article