[Immunohistochemical and molecular pathological diagnosis of lung carcinoma]. / Immunhistochemische und molekularpathologische Diagnostik von Lungenkarzinomen.

The therapy of lung cancer has revolutionarily changed within the last 15 years. The prognosis of patients has dramatically improved due to targeted therapies, for instance tyrosine kinase inhibitors (TKI). Current recruiting studies are testing new MET-, KRAS-, ROS1-, RET- and NTRK-inhibitors. The first clinical data are promising, emphasizing that it remains a future challenge for pathologists and oncologists to keep an eye on all facets of therapy options. Today, precise lung cancer classification via immunohistochemistry and molecular pathology is crucial for the therapy and prognosis of patients. Further, new biopsy technologies lead to very small tumor tissue samples and cytological samples of high diagnostic quality. Therefore, the complexity of diagnosis needs a strategic procedure to minimize loss of tissue material. This assay gives an overview of efficient and target-orientated diagnostic procedures in consideration of current clinical trials.

Primary blood neutrophils express a functional cell surface Toll-like receptor 9.

Polymorphonuclear leukocytes (PMNs) represent one of the first lines of defense against pathogens. TLR9 is normally expressed in endosomes/lysosomes where it is activated by pathogen-derived DNA. Here we show that freshly isolated human and mouse primary PMNs express TLR9 at the cell surface ex vivo. Moreover, surface TLR9 expression is upregulated upon activation of PMNs with different stimuli and not only TLR9 agonists. Importantly, surface TLR9 is processed, active, and functional. TLR9 ligands, oligo-nucleotides containing unmethylated CpG motifs, indeed bind to surface TLR9 and binding was strongly observed at the cell surface of human cells expressing surface TLR9 and at the surface of WT but not TLR9-deficient mouse PMNs. Finally, CpG oligonucleotides cross-linked onto a solid phase and having no access to intracellular TLR9 are able to trigger cell surface TLR9 and induce neutrophil activation, even when endosomal acidification is inhibited. This is the first demonstration of a functional TLR9 expressed at the cell surface of human primary cells. This pathway may be triggered when pathogen-derived TLR9 ligands cannot reach the endosome, offering a rescue mechanism for neutrophil activation.

Integrative genomic analyses of European intrahepatic cholangiocarcinoma: Novel ROS1 fusion gene and PBX1 as prognostic marker.

BACKGROUND: Cholangiocarcinoma (CCA) is a fatal cancer of the bile duct with a poor prognosis owing to limited therapeutic options. The incidence of intrahepatic CCA (iCCA) is increasing worldwide, and its molecular basis is emerging. Environmental factors may contribute to regional differences in the mutation spectrum of European patients with iCCA, which are underrepresented in systematic genomic and transcriptomic studies of the disease. METHODS: We describe an integrated whole-exome sequencing and transcriptomic study of 37 iCCAs patients in Germany. RESULTS: We observed as most frequently mutated genes ARID1A (14%), IDH1, BAP1, TP53, KRAS, and ATM in 8% of patients. We identified FGFR2::BICC1 fusions in two tumours, and FGFR2::KCTD1 and TMEM106B::ROS1 as novel fusions with potential therapeutic implications in iCCA and confirmed oncogenic properties of TMEM106B::ROS1 in vitro. Using a data integration framework, we identified PBX1 as a novel central regulatory gene in iCCA. We performed extended screening by targeted sequencing of an additional 40 CCAs. In the joint analysis, IDH1 (13%), BAP1 (10%), TP53 (9%), KRAS (7%), ARID1A (7%), NF1 (5%), and ATM (5%) were the most frequently mutated genes, and we found PBX1 to show copy gain in 20% of the tumours. According to other studies, amplifications of PBX1 tend to occur in European iCCAs in contrast to liver fluke-associated Asian iCCAs. CONCLUSIONS: By analyzing an additional European cohort of iCCA patients, we found that PBX1 protein expression was a marker of poor prognosis. Overall, our findings provide insight into key molecular alterations in iCCA, reveal new targetable fusion genes, and suggest that PBX1 is a novel modulator of this disease.

Phagocytosis of dying tumor cells by human peritoneal mesothelial cells.

Peritoneal carcinomatosis is an advanced form of metastatic disease characterized by cancer cell dissemination onto the peritoneum. It is commonly observed in ovarian and colorectal cancers and is associated with poor patient survival. Novel therapies consist of cytoreductive surgery in combination with intraperitoneal chemotherapy, aiming at tumor cell death induction. The resulting dying tumor cells are considered to be eliminated by professional as well as semi-professional phagocytes. In the present study, we have identified a hitherto unknown type of 'amateur' phagocyte in this environment: human peritoneal mesothelial cells (HMCs). We demonstrate that HMCs engulf corpses of dying ovarian and colorectal cancer cells, as well as other types of apoptotic cells. Flow cytometric, confocal and electron microscopical analyses revealed that HMCs ingest dying cell fragments in a dose- and time-dependent manner and the internalized material subsequently traffics into late phagolysosomes. Regarding the mechanisms of prey cell recognition, our results show that HMCs engulf apoptotic corpses in a serum-dependent and -independent fashion and quantitative real-time PCR (qRT-PCR) analyses revealed that diverse opsonin receptor systems orchestrating dying cell clearance are expressed in HMCs at high levels. Our data strongly suggest that HMCs contribute to dying cell removal in the peritoneum, and future studies will elucidate in what manner this influences tumor cell dissemination and the antitumor immune response.

Cardiac metastasis causes paradoxical malignant embolism.

BACKGROUND: Embolic events play an important role in clinical everyday practice. Malignant arterial embolism is a rare nevertheless often fatal entity for cardiac, cerebral or systemic ischemia, requiring immediate diagnosis and treatment. CASE: This is a case report of a 65 years-old female, suffering from pulmonal adenocarcinoma, who was hospitalized due to neurological deficits caused by an acute ischemic stroke, followed by anterior myocardial infarction within 3 days. Diagnostic work-up revealed metastasis of the pulmonal adenocarcinoma in the right atrium and a patent foramen ovale. Histopathological examination of the coronary embolus verified paradoxical arterial embolism of the pulmonal adenocarcinoma into a coronary vessel and consequently cerebral arteries. CONCLUSION: The present case underlines the need for (i), consideration of malignant embolism, (ii) histopathological examination of the embolus to determine its etiology, and (iii) interdisciplinary discussion of individual therapeutic and prevention strategies in cancer patients with cerebral, cardiac or systemic embolic events.

Protein-loss of SWI/SNF-complex core subunits influences prognosis dependent on histological subtypes of intra- and extrahepatic cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an aggressive malignancy with a 5-year-survival rate of <10%, mainly due to diagnosis in advanced stages and limited therapeutic options in case of progressive disease. Recently, evidence has indicated that alterations in the SWI/SNF-complex (SWI/SNF) may have an important role in the tumorigenesis of CCA. SWI/SNF-related chromatin remodeling has been reported to be crucial for differentiation and tumor suppression, and loss-of-function mutations of SWI/SNF are present in 20% of human malignancies; however, at present, little is known about its relevance in CCA. In the present study, a cohort of 52 patients with the diagnosis of primary CCA was retrospectively collected. All patients underwent surgery with curative intent. Tissue microarray analysis was performed on each tumor for immunohistochemical loss-of-protein analysis of the SWI/SNF core subunits ARID1A, INI-1, BRG1, PBRM-1 and BRM, corresponding to the following CCA subtypes: Extrahepatic CCA (ECCA), small duct or large duct intrahepatic CCA (ICCA). Kaplan-Meier analysis was used to determine survival distribution and survival differences were evaluated by log-rank test. In total, 14 of 52 patients (~35%) exhibited protein-loss of any tested SWI/SNF core subunit. Notably, 17% of patients exhibited a loss of ARID1a; this was the protein loss with the highest frequency. Patients with small and large duct ICCA with protein-loss of any tested SWI/SNF subunit exhibited significantly worse survival compared with the wild-type cohort with proficient protein expression (P=0.013 and P=0.002), whereas no significant survival difference was detected for patients with ECCA. SWI/SNF and its core subunits may be considered promising predictive and therapeutic targets, and require further investigation in patients with CCA.

A Novel Hybrid Stent with Endoscopic Vacuum Therapy for Treating Leaks of the Upper Gastrointestinal Tract.

INTRODUCTION: Self-expanding metal stents (SEMS) are an established option for treating leaks in the upper gastrointestinal tract, and endoscopic vacuum therapy (EVT) has become a promising alternative. A novel approach is the use of an esophageal hybrid SEMS (VACStent®), which can maintain esophageal passage during EVT. We present the first study demonstrating successful use of the VACStent® for treating leaks of the upper gastrointestinal tract. METHOD: We performed a retrospective, single-center study of all patients who underwent endoscopic stenting with the VACStent® of leaks in the upper gastrointestinal tract. RESULTS: Indications for treatment with the VACStent® were: iatrogenic esophageal perforation (n = 1), spontaneous perforation (n = 2), esophageal fistula (n = 2), and anastomotic leak after upper gastrointestinal surgery (n = 5). Successful application of the VACStent® was achieved in all patients (n = 10; 100%) with a total of 15 interventions. VACStent® therapy was used as a first-line treatment in 5 patient (success rate 80%; 4 out 5 patients) and as a second-line treatment after failed previous endoscopic therapy in 5 patients (success rate 60%; 3 out of 5 patients). Overall, VACStent® treatment was successful in 70% of the patients (7 out of 10). No severe VACStent® treatment-related adverse events occurred. CONCLUSION: The initial experience has been that the technical application of the VACStent® is safe and technically feasible. However, due to the small number of patients this study could not show the clear advantages of this novel hybrid stent. More studies are necessary to show significant advantages.

Simvastatin reduces tumor cell adhesion to human peritoneal mesothelial cells by decreased expression of VCAM-1 and ß1 integrin.

Peritoneal carcinomatosis describes cancer metastasis onto the surface of the peritoneum. It is frequently caused by ovarian and colorectal cancer. Once a tumor has penetrated the peritoneum, cancer cells disseminate into the abdominal cavity. Additionally, surgery can account for the spread of free tumor cells. Their subsequent adhesion to mesothelial cells (HMCs) initiates peritoneal carcinomatosis. Therefore, this study analyzed the effect of simvastatin on tumor cell adherence. HMCs were isolated from human greater omentum. Fluorescence-labeled tumor cells (SKOV-3, OvCar-29, OAW42, FraWü; ovarian/HT29; colorectal) were incubated on confluent mesothelial monolayers with 10 µM simvastatin for 48 h. Adhesion was quantified using a fluorescence reader. Expression of the adhesion molecules VCAM-1, ICAM-1 and ß1 integrin chain under the influence of simvastatin 0.1-100 µM for 24-72 h was analyzed using flow cytometry. Simvastatin significantly reduced the adhesion of all ovarian cancer cells and HT29 to HMCs (P≤0.001). Concomitantly simvastatin decreased the expression of VCAM-1 on HMCs. ICAM-1 and ß1 integrin chain expression on ovarian cancer cells was also clearly reduced. By contrast, the expression of the analyzed adhesion molecules on HT29 cells remained unchanged. Simvastatin clearly inhibits tumor cell adhesion to HMCs. In the case of ovarian cancer cell lines it appears to be mediated by decreased expression of both VCAM-1 on HMCs and the integrin α4ß1 on tumor cells. As an example of adhesion molecule down-regulating drugs, simvastatin may provide a novel therapeutic approach to the prevention of peritoneal carcinomatosis.

Multiple virulence factors are required for Staphylococcus aureus-induced apoptosis in endothelial cells.

Staphylococcus aureus infections can result in sepsis and septic shock associated with vascular damage and multiple organ failure. Apoptosis appears to play a key role during sepsis, and the ability of S. aureus to induce apoptosis in endothelial cells might contribute to metastatic infection. In contrast to leukocytes, in human umbilical vein endothelial cells and two endothelial cell lines neither purified alpha-toxin nor staphylococcal supernatants were sufficient to induce apoptosis. Apoptosis induction instead required staphylococcal invasion as well as signals from metabolically active intracellular staphylococci. Only strongly haemolytic and invasive staphylococci, but not non-invasive strains induced apoptosis that was caspase-dependent but Fas-independent. However, only a subgroup of clinical isolates with an invasive and haemolytic phenotype induced apoptosis. Expression of alpha-toxin in a non-haemolytic strain partially restored apoptosis induction, suggesting a role of alpha-toxin as a trigger of apoptosis. Furthermore, infection of endothelial cells with isogenic mutants of various regulator genes revealed that apoptosis induction was dependent on the global regulator agr and the alternative sigma factor sigB, but not influenced by sarA. Together, our results indicate that the ability of S. aureus to induce apoptosis in endothelial cells is determined by multiple virulence factors.