Constitutive activation of NF-κB in human hepatocellular carcinoma: Evidence of a cytoprotective role

Activation of nuclear factor-κB (NF-κB) can promote or inhibit apoptosis. Oxidative stress is an important mechanism by which certain anticancer drugs kill cancer cells, and is also one of the mechanisms that activate NF-κB. We therefore examined hepatic expression of the NF-κB monomer p65 in human hepatocellular carcinoma (HCC) tissue samples from eight patients and compared it with their respective samples of surrounding liver tissues. We also studied the effect of NF-κB inhibition in human HCC cells exposed to oxidative stress, by infecting HuH7 cells with a recombinant adenovirus carrying mutant IκBα (mIκBα). Cultured HuH7 cells were infected with mIκBα or β-galactosidase (β-Gal) for 24 hr followed by treatment with increasing concentrations of H2O2. Cytotoxicity, NF-κB translocation, NF-κB DNA binding, cell proliferation, and apoptosis were determined. The monomer p65 was overexpressed in six of eight human HCC tissues. In HuH7 cells, introduction of mIκBα potently inhibited the translocation, activation, and DNA binding of NF-κB. In control (β-Gal-infected) HuH7 cells, exposure to H2O2 produced a dose-dependent increase in apoptosis, regardless of NF-κB status. mIκBα- mediated inhibition of NF-κB activation sensitized HuH7 cells to H 2O2-induced inhibition of cell growth, and further promoted cell death. Addition of H2O2 (200-500 μM) to control or mIκBα-infected HuH7 cells enhanced caspase-3 activity and cleavage. Adenovirus-mediated transfer of mIκBα potently inhibits NF-κB activity in HuH7 cells, and this enhances oxidative stress-induced cell killing. © Mary Ann Liebert, Inc.published_or_final_versio

Constitutive activation of NF-κB in human hepatocellular carcinoma: Evidence of a cytoprotective role

Activation of nuclear factor-κB (NF-κB) can promote or inhibit apoptosis. Oxidative stress is an important mechanism by which certain anticancer drugs kill cancer cells, and is also one of the mechanisms that activate NF-κB. We therefore examined hepatic expression of the NF-κB monomer p65 in human hepatocellular carcinoma (HCC) tissue samples from eight patients and compared it with their respective samples of surrounding liver tissues. We also studied the effect of NF-κB inhibition in human HCC cells exposed to oxidative stress, by infecting HuH7 cells with a recombinant adenovirus carrying mutant IκBα (mIκBα). Cultured HuH7 cells were infected with mIκBα or β-galactosidase (β-Gal) for 24 hr followed by treatment with increasing concentrations of H2O2. Cytotoxicity, NF-κB translocation, NF-κB DNA binding, cell proliferation, and apoptosis were determined. The monomer p65 was overexpressed in six of eight human HCC tissues. In HuH7 cells, introduction of mIκBα potently inhibited the translocation, activation, and DNA binding of NF-κB. In control (β-Gal-infected) HuH7 cells, exposure to H2O2 produced a dose-dependent increase in apoptosis, regardless of NF-κB status. mIκBα- mediated inhibition of NF-κB activation sensitized HuH7 cells to H 2O2-induced inhibition of cell growth, and further promoted cell death. Addition of H2O2 (200-500 μM) to control or mIκBα-infected HuH7 cells enhanced caspase-3 activity and cleavage. Adenovirus-mediated transfer of mIκBα potently inhibits NF-κB activity in HuH7 cells, and this enhances oxidative stress-induced cell killing. © Mary Ann Liebert, Inc.published_or_final_versio

Tissue biopsy for the diagnosis of amyloidosis: experience from some centres

A reliable diagnosis of amyloidosis is usually based on a tissue biopsy. With increasing options for specific treatments of the different amyloid diseases, an exact and valid diagnosis including determination of the biochemical fibril nature is imperative. Biopsy sites as well as amyloid typing principles vary and this paper describes methods employed at some laboratories specialised in amyloidosis in Europe, Japan and USA

Multiscale heterogeneity in gastric adenocarcinoma evolution is an obstacle to precision medicine

Cancer is a somatic evolutionary disease and adenocarcinomas of the stomach and gastroesophageal junction (GC) may serve as a two-dimensional model of cancer expansion, in which tumor subclones are not evenly mixed during tumor progression but rather spatially separated and diversified. We hypothesize that precision medicine efforts are compromised when clinical decisions are based on a single-sample analysis, which ignores the mechanisms of cancer evolution and resulting intratumoral heterogeneity. Using multiregional whole-exome sequencing, we investigated the effect of somatic evolution on intratumoral heterogeneity aiming to shed light on the evolutionary biology of GC

Performance of Epigenetic Markers SEPT9 and ALX4 in Plasma for Detection of Colorectal Precancerous Lesions

BACKGROUND: Screening for colorectal cancer (CRC) has shown to reduce cancer-related mortality, however, acceptance and compliance to current programmes are poor. Developing new, more acceptable non-invasive tests for the detection of cancerous and precancerous colorectal lesions would not only allow preselection of individuals for colonoscopy, but may also prevent cancer by removal of precancerous lesions. METHODS: Plasma from 128 individuals (cohort I - exploratory study: 73 cases / 55 controls) was used to test the performance of a single marker, SEPT9, using a real-time quantitative PCR assay. To validate performance of SEPT9, plasma of 76 individuals (cohort II - validation study: 54 cases / 22 controls) was assessed. Additionally, improvement of predictive capability considering SEPT9 and additionally ALX4 methylation was investigated within these patients. RESULTS: In both cohorts combined, methylation of SEPT9 was observed in 9% of controls (3/33), 29% of patients with colorectal precancerous lesions (27/94) and 73% of colorectal cancer patients (24/33). The presence of both SEPT9 and ALX4 markers was analysed in cohort II and was observed in 5% of controls (1/22) and 37% of patients with polyps (18/49). Interestingly, also 3/5 (60%) patients with colorectal cancer were tested positive by the two marker panel in plasma. CONCLUSIONS: While these data confirm the detection rate of SEPT9 as a biomarker for colorectal cancer, they also show that methylated DNA from advanced precancerous colorectal lesions can be detected using a panel of two DNA methylation markers, ALX4 and SEPT9. If confirmed in larger studies these data indicate that screening for colorectal precancerous lesions with a blood-based test may be as feasible as screening for invasive cancer

Vascular CXCR4 Expression – a Novel Antiangiogenic Target in Gastric Cancer?

BACKGROUND: G-protein-coupled receptors (GPCRs) are prime candidates for novel cancer prevention and treatment strategies. We searched for differentially expressed GPCRs in node positive gastric carcinomas. METHODOLOGY/PRINCIPAL FINDINGS: Differential expression of GPCRs in three node positive vs. three node negative intestinal type gastric carcinomas was analyzed by gene array technology. The candidate genes CXCL12 and its receptor CXCR4 were validated by real-time reverse-transcription polymerase chain reaction in an independent set of 37 gastric carcinomas. Translation was studied by immunohistochemistry in 347 gastric carcinomas using tissue microarrays as well as in 61 matching lymph node metastases. Protein expression was correlated with clinicopathological patient characteristics and survival. 52 GPCRs and GPCR-related genes were up- or down-regulated in node positive gastric cancer, including CXCL12. Differential expression of CXCL12 was confirmed by RT-PCR and correlated with local tumour growth. CXCL12 immunopositivity was negatively associated with distant metastases and tumour grade. Only 17% of gastric carcinomas showed CXCR4 immunopositive tumour cells, which was associated with higher local tumour extent. 29% of gastric carcinomas showed CXCR4 positive tumour microvessels. Vascular CXCR4 expression was significantly associated with higher local tumour extent as well as higher UICC-stages. When expressing both, CXCL12 in tumour cells and CXCR4 in tumour microvessels, these tumours also were highly significantly associated with higher T- and UICC-stages. Three lymph node metastases revealed vascular CXCR4 expression while tumour cells completely lacked CXCR4 in all cases. The expression of CXCL12 and CXCR4 had no impact on patient survival. CONCLUSIONS/SIGNIFICANCE: Our results substantiate the significance of GPCRs on the biology of gastric carcinomas and provide evidence that the CXCL12-CXCR4 pathway might be a novel promising antiangiogenic target for the treatment of gastric carcinomas

Deep learning trained on lymph node status predicts outcome from gastric cancer histopathology: a retrospective multicentric study

Aim Gastric cancer (GC) is a tumor entity with highly variant outcomes. Lymph node metastasis is a prognostically adverse biomarker. We hypothesized that GC primary tissue contains information that is predictive of lymph node status and patient prognosis and that this information can be extracted using Deep Learning (DL). Methods Using three patient cohorts comprising 1146 patients, we trained and validated a DL system to predict lymph node status directly from hematoxylin-and-eosin stained GC tissue sections. We investigated the concordance between the DL-based prediction from the primary tumor slides (aiN score) and the histopathological lymph node status (pN). Furthermore, we assessed the prognostic value of the aiN score alone and when combined with the pN status. Results The aiN score predicted the pN status reaching Area Under the Receiver Operating Characteristic curves (AUROCs) of 0.71 in the training cohort and 0.69 and 0.65 in the two test cohorts. In a multivariate Cox analysis, the aiN score was an independent predictor of patient survival with Hazard Ratios (HR) of 1.5 in the training cohort and of 1.3 and 2.2 in the two test cohorts. A combination of the aiN score and the pN status prognostically stratified patients by survival with p-values <0.05 in log-rank tests. Conclusion GC primary tumor tissue contains additional prognostic information that is accessible using the aiN score. In combination with the pN status, this can be used for personalized management of gastric cancer patients after prospective validation

Wetting films on chemically heterogeneous substrates

Based on a microscopic density functional theory we investigate the morphology of thin liquidlike wetting films adsorbed on substrates endowed with well-defined chemical heterogeneities. As paradigmatic cases we focus on a single chemical step and on a single stripe. In view of applications in microfluidics the accuracy of guiding liquids by chemical microchannels is discussed. Finally we give a general prescription of how to investigate theoretically the wetting properties of substrates with arbitrary chemical structures.Comment: 56 pages, RevTeX, 20 Figure

Caveolin-1 protects B6129 mice against Helicobacter pylori gastritis.

Caveolin-1 (Cav1) is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori) is a major risk factor for human gastric cancer (GC) where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES) but had reduced levels of CD25+ regulatory T-cells. Cav1-deficient human GC cells (AGS), infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies ("humming bird") compared to AGS cells stably transfected with Cav1 (AGS/Cav1). Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1) to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87) and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1) to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs) in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells