Biomedical subjects

Albert Roessner

Publications and source records attributed to Albert Roessner.

At least 37 records · Page 2Linked to original sources

PubMed2005

Establishment and characterization of the permanent human cell line C3842 derived from a secondary chondrosarcoma in Ollier's disease.

The permanent human cell line C3842 was established from a secondary chondrosarcoma in a typical case of Ollier's disease. In the present study, we analyzed the morphological, cytogenetic and molecular biological characteristics of the cultured cells in comparison with the original tumor and investigated the invasion properties of the tumor model using functional imaging of proteolysis, matrigel assay and chick chorioallantoic membrane assay. C3842 cells exhibit the typical features of malignant cartilage tumor cells in vitro, including the expression of collagen types II, IX, XI and aggrecan. The proteolytic ability of C3842 cells is attributed to the expression of several proteases, such as cathepsin B, urokinase plasminogen activator and matrix-metalloproteinase-2, which enable the cells to degrade collagen type I and to permeate matrigel matrix. In accordance with the biological features in vivo, C3842 cells are not able to invade through the epithelium of the chick chorioallantoic membrane. In conclusion, the cell line C3842 provides the first model of a secondary chondrosarcoma in Ollier's disease in vitro, which is characterized by distinct features of such malignant cartilage tumors.

Adult↗

PubMed2005

Inhibition of RICK/nuclear factor-kappaB and p38 signaling attenuates the inflammatory response in a murine model of Crohn disease.

Nuclear factor-kappaB (NF-kappaB) is the main target of anti-inflammatory therapies in human chronic inflammatory bowel diseases (IBD), Crohn disease, and ulcerative colitis. This study investigates the molecular anti-inflammatory mechanisms of SB203580, an inhibitor of the mitogen-activated protein kinase p38. The murine trinitrobenzene sulfonic acid (TNBS)-induced colitis was used as an established model of human Crohn disease. Here we show that SB203580 improved the clinical condition, reduced intestinal inflammation, and suppressed mRNA levels of pro-inflammatory cytokines elevated upon induction of colitis. Besides p38 kinase activity, the "classical" IkappaB-dependent NF-kappaB pathway was strongly up-regulated during colitis induction, whereas the "alternative" was not. SB203580 treatment resulted in a drastic down-regulation of p38 and NF-kappaB activity. The molecular analysis of NF-kappaB activation revealed that Rip-like interacting caspase-like apoptosis-regulatory protein kinase (RICK), a key component of a pathway leading to NF-kappaB induction, is also strongly inhibited by SB203580. In contrast, SB203580 had no effect on the colitis-induced activation of other potential NF-kappaB-activating kinases such as protein kinase C (PKC), mixed lineage kinase 3, and the oncogene product Cot/TPL2. Thus, the inhibitory effect of SB203580 on NF-kappaB activation is to a large extent mediated by RICK inhibition. RICK is the effector kinase of the intracellular receptor of bacterial peptidoglycan NOD. Because bacterial products are suggested to be the key pathogenic agents triggering IBD, inhibition of the NOD/RICK pathway may serve as a novel target of future therapies in human IBD.

Animals↗

PubMed2005

Loss of p16 protein defines high-risk patients with gastrointestinal stromal tumors: a tissue microarray study.

Despite clearly defined histologic criteria, the prediction of tumor behavior for patients with gastrointestinal stromal tumors (GIST) still poses a challenge to pathologists. Therefore, searching for alternative markers that allow for better prognostic evaluation is an important task. To determine the practicability of immunohistochemical staining for p16 in clinical cases, we examined p16 protein expression in a group of 284 GISTs, a subset of which had long-term follow-up (median, 45 months; range, 1-204 months). P16 protein expression was ascertained on tissue microarrays as well as on standard sections. Survival analyses were carried out in 157 patients. P16 loss was found in 50% of GISTs, there being no correlation with age, sex, histologic subtype, signs of necrosis, or metastases. Patients having p16-negative tumors had a worse prognosis than those with p16-positive tumors (P = 0.012) with a 2.3-fold relative increased risk of dying of disease. P16 loss identified a subgroup of gastric tumors with a worse prognosis (P = 0.03). The multivariate configural frequency analysis identified two "antitypes," whose observed frequency was found to be significantly lower than the expected frequency [i.e., marker combinations: p16 positive, no metastases, and death of disease and p16 loss, metastases, and still alive]. The "type" whose observed frequency was significantly higher than the expected frequency consisted of the following marker pattern: p16 loss, necrosis, and death of disease (P < 0.001). In the multivariate Cox regression analysis, p16 loss, necrosis, and metastases each had independent prognostic value. P16 loss is a common molecular abnormality in GISTs and might be used in routine diagnosis to identify patients with high-risk tumors.

Adolescent↗

PubMed2005

Up-regulation of cathepsin X in Helicobacter pylori gastritis and gastric cancer.

Recently, we identified increased cathepsin X expression in H. pylori-infected gastric mucosa. Here, we describe further up-regulation in gastric cancer and report on the role of inflammatory cytokines required for cathepsin X up-regulation in H. pylori-infected gastric mucosa, as well as on consequences for cellular invasion. Biopsy specimens were taken from the antrum, corpus and cardia of H. pylori-infected and non-infected patients. Gastric cancer samples were obtained from patients undergoing gastric surgery. Cathepsin X was detected in gastric mucosa by quantitative real-time RT-PCR, western blotting and immunohistochemistry. Induction of cathepsin X expression in epithelial and inflammatory cells caused by H. pylori infection was tested in in vitro contact and non-contact co-cultures of AGS cells and monocytic cells. Patients with H. pylori gastritis showed significantly higher cathepsin X mRNA (2.5-fold) and protein (1.6-fold) expression than H. pylori-negative patients. Cathepsin X was also up-regulated in gastric cancer (3-12-fold) compared to non-neoplastic mucosa. Cathepsin X was predominantly expressed by macrophages in the mucosal stroma and in glands of the antral mucosa. In addition, tumour cells stained for cathepsin X in 26 (68%) patients with gastric carcinoma. In general, staining was significantly more common (20 vs. 6 patients) and more intense (3.55 vs. 0.83) in intestinal type gastric cancer than in the diffuse type. In vitro cell culture experiments revealed that intercellular signalling between pathogenicity island (PAI)-positive H. pylori-infected epithelial cells and macrophages via soluble factors in the culture medium seems to be responsible for increased expression of cathepsin X in monocytes. Using antisense oligonucleotides, cathepsin X up-regulation was directly associated with higher invasiveness in vitro. Although no correlation of cathepsin X expression and TNM stage was found, our study demonstrates that cathepsin X plays a role not only in the chronic inflammation of gastric mucosa but also in the tumourigenesis of gastric cancer.

Adult↗

PubMed2005

Overexpression of cathepsin B in gastric cancer identified by proteome analysis.

We aimed to validate an analytical approach based on proteomics on gastric cancer specimens for the identification of new putative diagnostic or prognostic markers. Primary screening was performed on gastrectomy specimens obtained from ten consecutive patients with gastric cancer. Gastric epithelial cells were obtained with an epithelial cell enrichment technique, homogenized and then separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The differential protein expression pattern was verified stepwise by Western blotting and immunohistochemistry on samples from 28 and 46 cancer patients, respectively. The putative clinical applicability and prognostic use were tested by an enzyme-linked immunoabsorbent assay on serum samples obtained from 149 cancer patients. One hundred-ninety-one differentially expressed protein spots were found by 2-D PAGE and identified by mass spectrometry, including cathepsin B, which was over-expressed in six (60%) patients. Western blotting confirmed that the active form of cathepsin B is over-expressed, while immunohistochemistry showed strong cytoplasmic staining in cancer tissues of 45 (98%) patients. The serum level of cathepsin B was increased in patients with gastric cancer compared to healthy controls (P = 0.0026) and correlated with T-category and the presence of distant metastases (P < 0.05). Serum levels above 129 pmol x L(-1) were associated with a reduced survival rate (P = 0.0297). Proteome analysis is a valuable tool for the identification of prognostic markers in gastric cancer: Increased cathepsin B serum levels are associated with advanced tumor stages and progressive disease, which enables the classification of some gastric cancer patients into a subgroup that should undergo aggressive therapy.

Adult↗

PubMed2005

Histogenesis of intralesional fibrous septum in chordoma.

Intralesional fibrous septum (IFS), a histologic architecture that is typical of chordoma, consists of proliferating spindle-shaped, fibroblast-like cells with an abundance of collagen fibers. However, the histogenesis of IFS is still controversial. In a series of 122 chordomas, special emphasis was placed on the morphology of host tissues involved in IFS and on a transition between IFS and neighboring tissues. In 23 lesions, IFS was also characterized both histochemically and immunohistochemically. IFS was observed in 79 (64.8%) lesions. Occasionally, IFS contained bone fragments and hyalinized matrix with no lining of osteoblastic cells, suggesting degenerated rather than metaplastic bone tissue. Moreover, IFS occasionally showed a direct transition to host bone trabeculae. Histochemically and immunohistochemically, IFS included calcium deposits positive for Alizarin red S staining and expressed both type I and type III collagen. In extraosseous lesions extending to the adjacent soft tissues, IFS frequently involved muscle fibers or peripheral nerve fibers and displayed a smooth transition to neighboring soft tissues. We believe that IFS is induced by a tumor-host interaction that is based on the host bone trabeculae in intraosseous lesions or on soft tissues in extraosseous lesions.

Adolescent↗

PubMed2005

Expression and function of somatostatin receptors in peripheral nerve sheath tumors.

Although somatostatin receptors have been detected in many normal and neoplastic tissues, little is known of their expression and function in peripheral nerve tumors. In the present study, we examined the expression of all 5 somatostatin receptor subtypes (sst1-5) in 3 normal peripheral nerves, 3 traumatic neuromas, 27 schwannomas, 18 neurofibromas, and 177 malignant peripheral nerve sheath tumors (MPNSTs) by immunohistochemistry as well as by Western blot and reverse transcriptase-polymerase chain reaction investigations in 2 normal peripheral nerves, one neurofibroma, 5 schwannomas, and 5 MPNSTs. Immunoreactive somatostatin receptors were not detectable in normal peripheral nerve and in nonneoplastic Schwann cell proliferations. In contrast, sst2A mRNA and protein was present in 89% of schwannomas. This receptor subtype was less frequently detected in neurofibromas (22%) and MPNSTs (15%). Interestingly, sst4 was seen in 32% of MPNSTs and was almost exclusively expressed in this malignant tumor type. In support of a role in Schwann cell tumor growth control by somatostatin was the observation of induced internalization of sst2A and inhibition of cell proliferation in an NF1-associated MPNST cell line. Moreover, administration of an sst2A-selective agonist resulted in induction of MPNST cell apoptosis. We conclude that peripheral nerve sheath tumors often express at least one functional somatostatin receptor. Furthermore, our findings suggest a potential clinical role for somatostatin receptor agonists in tumor imaging and/or treatment of schwannomas and MPNSTs.

Animals↗

PubMed2005

Small-bowel metaplasia arising in the remnant esophagus after esophagojejunostomy--a [corrected] prospective study in patients with a history of total gastrectomy.

OBJECTIVES: The pathogenesis of Barrett's mucosa is incompletely understood. Acidic gastro-esophageal reflux is considered an essential causative factor. The aim of this study was to detect esophageal columnar metaplasia after total gastrectomy with esophagojejunostomy, a condition of enteric, but nonacidic reflux. METHODS: In a prospective study, patients with a history of total gastrectomy and esophagojejunostomy were investigated for the presence of columnar metaplasia in the remnant esophagus. Patients with such history, who were now referred for esophagogastroduodenoscopy, were included during a 2-yr period. Biopsies for histopathology were taken from the anastomosis and any columnar metaplasia of the esophagus. RESULTS: In 8 of 25 patients (32%) with a history of gastrectomy, columnar metaplasia was found in the remnant esophagus, mostly in shape of tongues, partly associated with erosive reflux esophagitis. Histopathology showed a typical small-bowel mucosa, but with some villous atrophy. In a resection specimen, a double-layered muscularis mucosa was present, which proved the metaplastic nature of the intestinal mucosa. Length of the columnar metaplasia correlated with the time interval since surgery. CONCLUSIONS: Esophageal mucosa, if exposed long term to an enteric, but nongastric refluxate, can evolve into a highly differentiated intestinal metaplasia, which resembles small-bowel mucosa. This proves that complete-type intestinal metaplasia may arise not only in the stomach, but also in the esophagus. Esophageal intestinalization seems to reflect adaptation to enteric reflux.

Aged↗

PubMed2005

The angiotensin I-converting enzyme gene insertion/deletion polymorphism is linked to early gastric cancer.

The insertion/deletion polymorphism of the angiotensin I-converting enzyme (ACE) gene has recently been linked to the pathogenesis and progression of human cancers. Using genomic DNA from 88 patients with early gastric cancer confined either to mucosa (pT(1a)) or submucosa (pT(1b)), we assessed the insertion (I) and deletion (D) polymorphism by PCR analysis and compared it with a large noncancer control population (n = 145). In the noncancer control group, the II genotype was observed in 33 (23%) individuals, whereas the ID and DD genotypes were found in 72 (50%) and 40 (27%) individuals, respectively. Interestingly, in the cancer group, we found the II genotype in six (7%) patients and the ID genotype in 46 (52%) individuals, whereas the DD genotype was observed in 36 (41%) individuals (P = 0.0034). Accordingly, the odds ratio for the II genotype was 0.20 [95% confidence interval (95% CI), 0.08-0.54; P = 0.009] and 0.55 for the ID/II genotype (95% CI, 0.31-0.96; P = 0.044) using the high-activity genotype DD as the reference category. No correlation was found among tumor type, tumor stage, the presence of Helicobacter pylori, and the ACE genotype. Our study provides further evidence that the ACE insertion/deletion gene polymorphism may be linked to the development of early gastric cancer.

Adult↗

PubMed2005

Hereditary lattice corneal dystrophy is associated with corneal amyloid deposits enclosing C-terminal fragments of keratoepithelin.

PURPOSE: To investigate the molecular basis of hereditary lattice corneal dystrophy (LCD) type IIIA associated with corneal amyloid deposits afflicting several members of a four-generation family. METHODS: Histologic, immunohistochemical and biochemical studies were performed on corneal tissue samples obtained after perforating keratoplasty. DNA was extracted from peripheral blood leukocytes. All exons of the keratoepithelin-encoding TGFBI gene were amplified and sequenced. The presence of a mutation was confirmed by digestion of the isolated PCR product with the restriction enzyme AlwNI. RESULTS: The cornea of the index patient (II-1) contained large patchy deposits of amyloid, which were immunoreactive for the C terminus of keratoepithelin. Western blot analysis of the polypeptide chains extracted from the amyloid deposits of paraffin-embedded tissue revealed that these represented mainly fragments of the full-length protein. The smallest fragments were 6.5 and 6.9 kDa. DNA analyses of the TGFBI gene revealed a heterozygous T-->C transition at the second position of codon 540 in exon 12, indicating that replacement of phenylalanine by serine (Phe540Ser) leads to dominant disease. The mutation creates a new restriction site for the enzyme AlwNI. Five of the examined family members carried this mutation. Three of them (aged >/=41 years) had the disease, two family members (aged <20 years) do not yet show any clinical symptoms. An additional inconsequential single-nucleotide polymorphism (T1667C) was found at the third position of the same codon (Phe540Phe) in three unaffected family members. CONCLUSIONS: This is the first report of a single-nucleotide mutation at codon 540 of TGFBI leading to LCD, and the first to demonstrate that the amyloid deposits in LCD contain proteolytic fragments of keratoepithelin.

Adult↗

PubMed2005

Intralesional fibrous septum in chordoma: a clinicopathologic and immunohistochemical study of 122 lesions.

Intralesional fibrous septum (IFS) generally is considered a reactive tissue in chordoma; however, little is known about its significance. We studied 122 chordomas for IFS using immunohistochemical techniques and compared IFS and lobular growth patterns (LGPs) formed by IFS with clinicopathologic parameters. Seventy-nine tumors (64.8%) revealed IFS. However, IFS frequently was infiltrated and interrupted by tumor cells with increased expression of proteases; only 33 (42%) of 79 tumors had LGP. In non-skull base chordomas, IFS and LGP were associated with nuclear pleomorphism, a previously described prognostic indicator, mitosis, and the MIB-1 labeling index, indicating a role of IFS and LGP in tumor growth or progression. Paradoxically, patients without LGP tended to have a worse prognosis than those with LGP. We believe that IFS exerts diverse influences on chordoma; however, invasion of IFS leading to loss of the LGP indicates advanced stages of tumor development, possibly predicting an unfavorable prognosis in chordoma.

Bone Neoplasms↗

PubMed2005

Hypermethylation and loss of expression of glutathione peroxidase-3 in Barrett's tumorigenesis.

Chronic gastroesophageal reflux disease is a known risk factor for Barrett's esophagus (BE), which induces oxidative mucosal damage. Glutathione peroxidase-3 (GPx3) is a secretory protein with potent extracellular antioxidant activity. In this study, we have investigated the mRNA and protein expression of GPx3, and explored promoter hypermethylation as an epigenetic mechanism for GPx3 gene inactivation during Barrett's carcinogenesis. Quantitative real-time reverse transcription polymerase chain reaction on 42 Barrett's adenocarcinomas (BAs) revealed consistently reduced levels of GPx3 mRNA in 91% of tumor samples. GPx3 promoter hypermethylation was detected in 62% of Barrett's metaplasia, 82% of dysplasia, and 88% of BA samples. Hypermethylation of both alleles of GPx3 was most frequently seen in BAs (P = .001). Immunohistochemical staining of GPx3 in matching tissue sections (normal, BE, Barrett's dysplasia, and BA) revealed strong immunostaining for GPx3 in normal esophageal and gastric tissues. However, weak to absent GPx3 staining was observed in Barrett's dysplasia and adenocarcinoma samples where the promoter was hypermethylated. The degree of loss of immunohistochemistry correlated with the hypermethylation pattern (monoallelic versus biallelic). The observed high frequency of promoter hypermethylation and progressive loss of GPx3 expression in BA and its associated lesions, together with its known function as a potent antioxidant, suggest that epigenetic inactivation and regulation of glutathione pathway may be critical in the development and progression of BE.

Adenocarcinoma↗

PubMed2005

The disintegrin-metalloproteinases ADAM9, ADAM12, and ADAM15 are upregulated in gastric cancer.

The ADAMs (A disintegrin and metalloproteinase) are a family of cell-surface membrane glycoproteins, whose multidomain structure enables diverse roles in a wide range of cellular processes. Accumulating evidence associates an increased expression of individual ADAM family members with various types of cancer, and we investigated the possible involvement of ADAM9, 12 and 15 in the pathogenesis of gastric cancer (GC). Using immunohistochemistry and quantitative RT-PCR, we examined the transcription and expression pattern of ADAM9, 12, and 15 in GCs and the corresponding non-tumor tissue, and in GC cell lines (AGS, MKN45, MKN28, NCI-N87, KATOIII). All three ADAMs were found to be significantly upregulated in GC compared to non-neoplastic foveolar epithelium, with ADAM12 expression being higher in intestinal- than in diffuse-type tumors. In vitro proliferation assays were used to evaluate the effects of ADAM-specific antibodies on the growth of GC cell lines. The administration of anti-ADAM9 and anti-ADAM15 antibodies inhibited cell growth, whereas anti-ADAM12 enhanced the proliferation of the GC cell lines. ADAM9, 12 and 15 are implicated in the malignant growth of GC cells, perhaps via the interaction with adhesion molecules, or the proteolytic 'shedding' of signaling molecules and the consequent transactivation of their receptors, such as the epithelial growth factor receptor and its ligands. The resultant modulation of the tumor-host interface may contribute to the pathogenesis, development or progression of gastric cancer.

ADAM Proteins↗

PubMed2005

Promoter hypermethylation of p16INK4a, E-cadherin, O6-MGMT, DAPK and FHIT in adenocarcinomas of the esophagus, esophagogastric junction and proximal stomach.

Although the incidence of Barrett's carcinomas (BC) and proximal gastric adenocarcinomas (PGC) is increasing, little is known about different epigenetic changes in these etiopathogenetically distinct entities. Therefore, 29 adenocarcinomas [10 BC, 7 PGC and 12 tumors of the esophagogastric junction (JC)] and corresponding non-tumor controls (NT) were examined using methylation-specific PCR. The most striking result was a significantly higher promoter methylation frequency of O6-methylguanine methyl transferase (MGMT) in BC compared with JC and PGC (0.7 vs. 0.08 vs. 0.29, respectively; p = 0.011; methylation exclusively in tumors), confirmed immunohistochemically by a significant loss of MGMT protein in BC (p = 0.006). Therefore, MGMT might become a prognosticator and key for chemotherapy with alkylating agents in BC. Frequencies of p16INK4a promoter methylation were 0.5 (BC), 0.42 (JC) and 0.29 (PGC; n.s.), but methylation was almost absent in NT controls. As immunonegative tumors slightly outnumber methylation-positive cases, other mechanisms of gene inactivation must be discussed. Methylation of E-cadherin was rarely observed (1/10 BC, 0/12 JC and 2/7 PGC). This is the first report on promoter methylation of death-associated protein kinase (DAPK) and fragile histidine triad gene (FHIT) in BC; both DAPK (BC 0.7, JC 0.92 and PGC 0.86) and FHIT (BC 0.88, JC 1.0 and PGC 1.0) were found to be highly methylated, suggesting that epigenetic silencing of these tumor suppressors is a common event in adenocarcinomas of the upper gastrointestinal tract, including BC. DAPK (0.54 on average) and FHIT methylation (0.77 on average) were also observed in NT samples. This might constitute an early epigenetic precursor lesion in the normally-appearing tissue surrounding the tumor.

Acid Anhydride Hydrolases↗

PubMed2004

5-Aza-cytidine is a potent inhibitor of DNA methyltransferase 3a and induces apoptosis in HCT-116 colon cancer cells via Gadd45- and p53-dependent mechanisms.

Methyltransferase inhibitors commonly used in clinical trials promote tumor cell death, but their detailed cytotoxic action is not yet fully understood. A deeper knowledge about their apotosis-inducing mechanisms and their interaction with DNA methyltransferases (DNMTs) DNMT1, DNMT3a, and DNMT3b might allow the design of more effective drugs with lower cytotoxicity. 5-aza-cytidine (5-aza-CR), a potent inhibitor of DNMT1, is known to induce demethylation and reactivation of silenced genes. In this study, we investigated the p53 dependence of apoptotic, cell cycle, and growth inhibitory effects of 5-aza-CR, as well as the influence on the expression level of DNMT1, DNMT3a, and DNMT3b in the colon cancer cell line HCT-116. Exposure to 5-aza-CR induced the up-regulation of genes promoting cell cycle arrest and DNA repair (p21(WAF1) and GADD45) or apoptosis (p53, RIPK2, Bak1, caspase 5, and caspase 6). In parallel, there was a down-regulation of antiapoptotic Bcl2 protein and the G(2)/M-mediator cyclin B1. Co-incubation with pifithrin-alpha (PFT-alpha), a selective p53 inhibitor, restored GADD45, Bcl2, cyclin B1, and p21(WAF1) expression levels and almost completely reversed the growth inhibitory, cell cycle, and apoptotic effects of 5-aza-CR. 5-aza-CR treatment caused global demethylation and reactivation of p16(INK4) expression. There was a marked decrease in DNMT1 and DNMT3a mRNA expression, with PFT-alpha reversing these effects. However, 5-aza-CR treatment did not modulate DNMT3b expression. Our data demonstrate that 5-aza-CR action in HCT-116 is mediated by p53 and its downstream effectors p21(WAF1) and GADD45. This is the first report to show a link between p53 and regulation of DNMT1 and de novo methyltransferase DNMT3a.

Annexin A5↗

PubMed2004

Interactions between human colon carcinoma cells, fibroblasts and monocytic cells in coculture--regulation of cathepsin B expression and invasiveness.

To elucidate the importance of the tumor/host interaction in malignant tumors, we investigated the colon carcinoma cell line HT-29 in coculture with monocytic cells (THP-1) and fibroblasts (175BR) for cathepsin B expression and activity. The tumor cells were grown in monolayer cultures or as multicellular tumor spheroids. After coculture, the three cell types were separated by labeled magnetic beads for cathepsin B mRNA and protein analysis. The invasive potential was studied in in vitro invasion assays. The expression level of cathepsin B was found to be 10-fold increased in three dimensional spheroids of HT-29 compared to HT-29 monolayers. The coculture of HT-29 with THP-1 cells and/or human fibroblasts led to a considerable increase in cathepsin B mRNA expression in both tumor and tumor-associated cells. The invasive potential of the tumor cells was 5 times increased by adding monocytic cells to the assay system. This is dependent on the functional activity of cathepsin B as shown by specific siRNA's and seems to be regulated by activation of ERK1/2 and p38 signal transduction pathways.

Carcinoma↗

PubMed2004

Analysis of the type IV secretion system-dependent cell motility of Helicobacter pylori-infected epithelial cells.

The pathogenesis of Helicobacter pylori-associated disorders is strongly dependent on a specialized type IV secretion system (T4SS) encoded by the cag pathogenicity island (PAI). Cytotoxin-associated gene A (CagA) is the only known H. pylori protein translocated into the host cell followed by tyrosine phosphorylation through host protein kinases. H. pylori induces cellular processes which are either PAI- or CagA-dependent (e.g., cell motility), PAI-dependent, but CagA-independent (e.g., interleukin-8 release), or PAI- and CagA-independent (e.g., cyclooxygenase-2 release). Here, we investigated H. pylori strains mutated in single PAI genes of the wild type strain Hp26695 and their effects on cell motility. We found 17 gene products out of 27 PAI genes playing a superordinated role and five PAI-encoded proteins exhibiting a clearly critical role in motogenic host cell responses, whereas the remaining five PAI gene products had no significant influence on the motogenic response in reaction to H. pylori infection. This study clearly demonstrated that H. pylori-induced cell motility and invasive growth involve type IV secretion system-dependent signalling as well as translocated and phosphorylated CagA. These findings reveal a deeper insight in to the meaning of the T4SS of H. pylori for host cell motility.

Antigens, Bacterial↗

PubMed2004

Synchronous granulomatous cholecystitis and fibroelastosis of the gallbladder.

We describe an unusual form of xanthogranulomatous cholecystitis in a 69-year-old man, with abundant intramural concrement formation and a local fibroelastosis of the adjacent interstitium and arteries. The gallbladder was obtained following resection of an adenocarcinoma of the gastro-esophageal junction without evidence of metastases. Only two cases of fibroelastosis of the gallbladder have previously been reported, and its pathogenesis is unknown. The influence of bile that leaked into the interstitium or a specific local tissue response to cytokines secreted by histiocytes are among the possible explanations for its development in our case.

Aged↗