Christina Perske

Colorectal cancer in two pre-teenage siblings with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant disorder that characteristically presents with colon cancer in early adult life. We describe a Pakistani FAP family in which two sons had an unusually early manifestation of colorectal cancer. The index patient presented at 11 years of age with abdominal pain, rectal bleeding and iron deficiency anaemia. Colonoscopy showed that the colon was carpeted with a myriad of polyps. Oesophago-gastric and duodenal endoscopy revealed that polyps had also developed in the duodenum. Multiple biopsies indicated neoplastic lesions. The patient underwent a proctocolectomy and endoscopic duodenal mucosectomy. The diagnosis of an adenocarcinoma of the colon and further adenomatous polyps with low-grade and high-grade dysplasia was confirmed by histology. Family screening including a blood test for anaemia and bowel examination revealed that his 12-year-old brother was also affected. Conclusion:Children with familial adenomatous polyposis are at risk for colon cancer and emphasise the need for early tumour recognition. Gastrointestinal symptoms in children should be thoroughly evaluated and standard screening for colonic polyposis should be performed in all individuals with a positive family history and/or known mutations in cancer-associated genes, particularly in children who are under 10 years of age.

FLT3-ITD and TLR9 use Bruton tyrosine kinase to activate distinct transcriptional programs mediating AML cell survival and proliferation

Acute myeloid leukemia (AML) is driven by niche-derived and cell-autonomous stimuli. Although many cell-autonomous disease drivers are known, niche-dependent signaling in the context of the genetic disease heterogeneity has been difficult to investigate. Here, we analyzed the role of Bruton tyrosine kinase (BTK) in AML. BTK was frequently expressed, and its inhibition strongly impaired the proliferation and survival of AML cells also in the presence of bone marrow stroma. By interactome analysis, (phospho)proteomics, and transcriptome sequencing, we characterized BTK signaling networks. We show that BTK-dependent signaling is highly context dependent. In Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD)-positive AML, BTK mediates FLT3-ITD-dependent Myc and STAT5 activation, and combined targeting of FLT3-ITD and BTK showed additive effects. In Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD)-negative AML, BTK couples Toll-like receptor 9 (TLR9) activation to nuclear factor κΒ and STAT5. Both BTK-dependent transcriptional programs were relevant for cell cycle progression and apoptosis regulation. Thus, we identify context-dependent oncogenic driver events that may guide subtype-specific treatment strategies and, for the first time, point to a role of TLR9 in AML. Clinical evaluation of BTK inhibitors in AML seems warranted.

Loss of Inducible Nitric Oxide Synthase Expression in the Mouse Renal Cell Carcinoma Cell Line RENCA Is Mediated by MicroRNA miR-146a

Tumor-associated macrophages can potentially kill tumor cells via the high concentrations of nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS); however, tumor-associated macrophages actually support tumor growth, as they are skewed toward M2 activation, which is characterized by low amounts of NO production and is proangiogenic. We show that the mouse renal cell carcinoma cell line, RENCA, which, on stimulation, expresses high levels of iNOS mRNA, loses its ability to express the iNOS protein. This effect is mediated by the microRNA miR-146a, as inhibition of RENCA cells with anti-miR- 146a restores iNOS expression and NO production (4.8 ± 0.4 versus 0.3 ± 0.1 μmol/L in uninhibited cells, P < 0.001). In vivo, RENCA tumor cells do not stain for iNOS, while infiltrating tumor-associated macrophages showed intense staining, and both cell types expressed iNOS mRNA. Restoring iNOS protein expression in RENCA cells using anti-miR-146a increases macrophage-induced death of RENCA cells by 73% (P < 0.01) in vitro and prevents tumor growth in vivo. These results suggest that, in addition to NO production by macrophages, tumor cells must produce NO to induce their own deaths, and some tumor cells may use miR-146a to reduce or abolish endogenous NO production to escape macrophage-mediated cell death. Thus, inhibiting miR-146a may render these tumor cells susceptible to therapeutic strategies, such as adoptive transfer of M1-activated macrophages.

Effects of pulmonary acid aspiration on the lungs and extra-pulmonary organs: a randomized study in pigs

IntroductionThere is mounting evidence that injury to one organ causes indirect damage to other organ systems with increased morbidity and mortality. The aim of this study was to determine the effects of acid aspiration pneumonitis (AAP) on extrapulmonary organs and to test the hypothesis that these could be due to circulatory depression or hypoxemia.MethodsMechanically ventilated anesthetized pigs were randomized to receive intrabronchial instillation of hydrochloric acid (n = 7) or no treatment (n = 7). Hydrochloric acid (0.1 N, pH 1.1, 2.5 ml/kg BW) was instilled into the lungs during the inspiratory phase of ventilation. Hemodynamics, respiratory function and computer tomography (CT) scans of lung and brain were followed over a four-hour period. Tissue samples of lung, heart, liver, kidney and hippocampus were collected at the end of the experiment.ResultsAcid instillation caused pulmonary edema, measured as increased extravascular lung water index (ELWI), impaired gas exchange and increased mean pulmonary artery pressure. Gas exchange tended to improve during the course of the study, despite increasing ELWI. In AAP animals compared to controls we found: a) cardiac leukocyte infiltration and necrosis in the conduction system and myocardium; b) lymphocyte infiltration in the liver, spreading from the periportal zone with prominent areas of necrosis; c) renal inflammation with lymphocyte infiltration, edema and necrosis in the proximal and distal tubules; and d) a tendency towards more severe hippocampal damage (P > 0.05).ConclusionsAcid aspiration pneumonitis induces extrapulmonary organ injury. Circulatory depression and hypoxemia are unlikely causative factors. ELWI is a sensitive bedside parameter of early lung damage.

Reelin signalling in neuroblastoma: migratory switch in metastatic stages.

The essential functions of Reelin for the migratory behaviour of neuroblasts in the central nervous system are well documented. Its role in the dissemination of neuronal tumours of the peripheral nervous system has not been studied in detail. Here, we examined neuroblastoma (NB), a tumour derived from sympathoadrenal cells of neural crest origin. We studied the expression of Reelin, its receptors VLDLR and LRP8 and the adapter protein DAB1 in primary tumour samples and cell lines. We used real-time RT-PCR, immunohistology and western blot analysis. In NB cell lines we studied effects of all-trans retinoic acid and the in vitro effects of Reelin. In primary tumour samples of untreated patients, a significant downregulation of Reelin and DAB1 mRNA was found in the metastatic stages 3, 4 and 4s. Immunohistochemical studies revealed expression of Reelin, LRP8 and DAB1 in differentiating-type low-grade NB. In vitro, western blot analysis of selected NB cell lines showed variable expression patterns. Differentiation induction with all-trans retinoic acid induced the upregulation of Reelin and DAB1. Reelin acted as a chemoattractant for various NB cell lines but inhibited migration when applied together with the NB cells. In normal tissue, we found Reelin in lymphatic endothelial cells (LECs) but not in blood vessel endothelium (BECs). In primary NB, both BECs and LECs were positive. Our data strongly suggest that Reelin has a dual role in NB. Autocrine expression marks low-grade differentiating tumour cells, whereas paracrine Reelin presented by LECs and BECs may act as a chemoattractant and promote hematogenic and lymphogenic dissemination in progressed stages.

Tumor-associated macrophages in clear cell renal cell carcinoma express both gastrin-releasing peptide and its receptor: a possible modulatory role of immune effectors cells

PurposeRenal cell carcinomas (RCC) frequently express the gastrin-releasing peptide receptor (GRP-R). Gastrin-releasing peptide (GRP) stimulates tumor cell proliferation and neoangiogenesis. Tumor-associated macrophages (TAM) comprise an important cellular component of these tumors. We analyzed the GRP/GRP-R network in clear cell RCC (ccRCC) and non-clear cell RCC (non-ccRCC) with special regard to its expression by macrophages, tumor cells and microvessels.MethodsGastrin-releasing peptide and GRP-R expression in 17 ccRCC and 9 non-ccRCC were analyzed by RT-PCR, immunohistochemistry and double immunofluorescence staining.ResultsTumor-associated macrophages expressed GRP and GRP receptor in ccRCC. Tumor cells and microvessels showed low to intermediate GRP-R expression in nearly all cases. In 12 ccRCC tumor epithelia also expressed low levels of GRP. Microvascular GRP expression was found in nine cases of ccRCC. For non-RCC, the expression of GRP and GRP receptor expression pattern was similar.ConclusionsTumor-associated macrophages are the main source of GRP in RCC. GRP receptor on TAM, tumor epithelia and microvessels might be a molecular base of a GRP/GRP receptor network, potentially acting as a paracrine/autocrine modulator of TAM recruitment, tumor growth and neoangiogenesis.

Mandibular reconstruction using a calcium phosphate/polyethylene glycol hydrogel carrier with BMP‐2

AIM To test the hypothesis that a synthetic hydroxyapatite/β-tricalcium phosphate (HA/TCP) construct combined with polyethylene glycol (PEG) hydrogel including recombinant human bone morphogenetic proteins-2 (rhBMP-2) enhances new bone formation compared with bone morphogenetic proteins-2 (BMP-2) delivered using the HA/TCP construct alone. MATERIAL AND METHODS Bilateral mandibular partial thickness 20 × 8 × 8 mm (L × W × H) alveolar defects were surgically created in the edentulated posterior mandible in 18 female minipigs. Randomized into two groups of nine animals each, the alveolar defects either received HA/TCP or HA/TCP/PEG with or without BMP-2 (105 μg/defect) in contra-lateral sites using a split-mouth design. Primary outcome, bone density (%) within four regions of interest, was evaluated following a 4-week healing interval when the animals were killed for histometric analysis. RESULTS Bone morphogenetic proteins-2 loaded onto HA/TCP constructs significantly enhanced new bone formation compared with HA/TCP controls. Adding PEG apparently obstructed BMP-2 induced bone formation. CONCLUSION Polyethylene glycol compromises the osteogenic effect of BMP-2.

Fungal encephalitis in human autopsy cases is associated with extensive neuronal damage but only minimal repair

The present study aimed at examining neuronal injury and repair in post mortem brain sections of humans who died from fungal central nervous system infections.

Effects of acute intracranial hypertension on extracerebral organs: a randomized experimental study in pigs.

BACKGROUND The study was conducted to determine the effects of isolated acute intracranial hypertension (AICH) on extracerebral organs. DESIGN A total of 14 mechanically ventilated pigs were randomized to two groups of seven each: (1) control and (2) AICH. METHODS AICH was induced by inflating an intracranial balloon catheter. The inflation volume was adjusted to keep intracranial pressure between 30 and 40 cm H2O. Hemodynamics, gas-exchange, and global oxygen delivery parameters were observed over a 4-hour period. At the end of the 4-hour period, tissue samples of heart, lungs, liver, and kidneys were collected and histologically graded for inflammation, edema, and cell damage (necrosis) using semiquantitative scores. RESULTS Animals with AICH had increased heart rate and cardiac output, and higher scores for inflammation, edema, and necrosis in heart, lung, kidney, and liver tissues (all p < 0.05). Peripheral and mixed-venous oxygen saturations were unaffected. CONCLUSIONS Isolated AICH induces injury to multiple extracerebral organs, even in the absence of hypoperfusion or hypoxemia.

Contrast Enhancement on Cone-Beam Breast-CT for Discrimination of Breast Cancer Immunohistochemical Subtypes

PURPOSE: To evaluate whether contrast enhancement on cone-beam breast-CT (CBBCT) could aid in discrimination of breast cancer subtypes and receptor status. METHODS: This study included female patients age >40 years with malignant breast lesions identified on contrast-enhanced CBBCT. Contrast enhancement of malignant breast lesions was standardized to breast fat tissue contrast enhancement. All breast lesions were approved via image-guided biopsy or surgery. Immunohistochemical staining was conducted for expression of estrogen (ER), progesterone (PR), human epidermal growth factor receptor-2 (HER2) and Ki-67 index. Contrast enhancement of breast lesions was correlated with immunohistochemical breast cancer subtypes (Luminal A, Luminal B, HER2 positive, triple negative), receptor status and Ki-67 expression. RESULTS: Highest contrast enhancement was seen for Luminal A lesions (93.6 HU) compared to Luminal B lesions (47.6 HU, P = .002), HER2 positive lesions (83.5 HU, P = .359) and triple negative lesions (45.3 HU, P = .005). Contrast enhancement of HER2 positive lesions was higher than Luminal B lesions (P = .044) and triple negative lesions (P = .039). No significant difference was evident between Luminal B and triple negative lesions (P = .439). Lesions with high Ki-67 index showed lower contrast enhancement than those with low Ki-67 index (P = .0043). ER, PR and HER2 positive lesions demonstrated higher contrast enhancement than their receptor negative counterparts, although differences did not reach statistical significance (P = .1714; P = .3603; P = .2166). CONCLUSIONS: Contrast enhancement of malignant breast lesions on CBBCT correlates with immunohistochemical subtype and proliferative potential. Thereby, CBBCT might aid in selecting individualized treatment strategies for breast cancer patients based on pre-operative imaging.