17ß-Hydroxysteroid dehydrogenase type 10 predicts survival of patients with colorectal cancer and affects mitochondrial DNA content.

Mitochondrial energy production is reduced in tumor cells, and altered mitochondrial respiration contributes to tumor progression. Synthesis of proteins coded by mitochondrial DNA (mtDNA) requires the correct processing of long polycistronic precursor RNA molecules. Mitochondrial RNase P, composed of three different proteins (MRPP1, HSD10, and MRPP3), is necessary for correct RNA processing. Here we analyzed the role of RNase P proteins in colorectal cancer. High HSD10 expression was found in 28%; high MRPP1 expression in 40% of colorectal cancers, respectively. Expression of both proteins was not significantly associated with clinicopathological parameters. Survival analysis revealed that loss of HSD10 expression is associated with poor prognosis. Cox regression demonstrated that patients with high HSD10 tumors are at lower risk. High HSD10 expression was significantly associated with high mtDNA content in tumor tissue. A causal effect of HSD10 overexpression or knock down with increased or reduced mtDNA levels, respectively, was confirmed in tumor cell lines. Our data suggest that HSD10 plays a role in alterations of energy metabolism by regulating mtDNA content in colorectal carcinomas, and HSD10 protein analysis may be of prognostic value.

Short-term intravenous fish-oil emulsions in pediatric oncologic patients--effect on liver parameters.

Pediatric oncologic patients often need parenteral nutrition (PN) during chemotherapy. Long-term use of soybean-based lipid emulsions is associated with progressive liver disease and cholestasis, whereas fish-oil based emulsions have anticholestatic effects. We studied the potentially hepato-protective effects of short-term use of SMOF lipids in children undergoing chemotherapy. Fifteen pediatric oncologic patients treated with SMOF lipids were retrospectively analyzed in respect to bilirubin and liver parameters and compared to matched-controls who had received soybean-based fat emulsions. For statistics the time-points baseline, Day 14 of PN (PN14), and post (Day+7) were chosen. None of the study patients developed cholestasis. Within the SMOF-lipid group there were no differences in the laboratory parameters between baseline, PN14, and post. In the control group, gamma glutamyltransferase (γGT) levels increased during PN (baseline vs. PN14, 26.43 vs. 63.00 U/l, P < 0.05). Lactate dehydrogenase (LDH) levels showed a significantly different behavior in the 2 groups: In the SMOF lipids group, LDH decreased whereas it increased in the controls (-32.75 U/l vs. + 29.57 U/l, P < 0.05). An advantage of fish oil-based fat emulsions can be shown even after short-term PN. In children undergoing chemotherapy the use of soybean-based fat emulsions but not SMOF lipids led to increased γGT levels.

Therapy-resistant acute lymphoblastic leukemia (ALL) cells inactivate FOXO3 to escape apoptosis induction by TRAIL and Noxa.

Forkhead transcription factors (FOXO) are downstream targets of the phosphoinositol-3-kinase (PI3K) protein kinase B (PKB) signaling cascade and play a pivotal role in cell differentiation, cell cycle and apoptosis. We found that cells from prednisone-resistant T-acute lymphoblastic leukemia (T-ALL) patients showed cytoplasmic localization of FOXO3 in comparison to prednisone-sensitive patients suggesting its inactivation. To determine the impact of FOXO3, T-ALL cells were infected with a 4OH-tamoxifen-regulated, phosphorylation-independent FOXO3(A3)ERtm allele. After FOXO3-activation these cells undergo caspase-dependent apoptosis. FOXO3 induces the death ligand TRAIL and the BH3-only protein Noxa implicating extrinsic as well as intrinsic death signaling. Whereas dnFADD partially inhibited cell death, CrmA and dnBID efficiently rescued ALL cells after FOXO3 activation, suggesting a caspase-8 amplifying feedback loop downstream of FADD. Knockdown of TRAIL and Noxa reduced FOXO3-induced apoptosis, implicating that mitochondrial destabilization amplifies TRAIL-signaling. The-reconstitution of the cell cycle inhibitor p16INK4A, which sensitizes ALL cells to mitochondria-induced cell death, represses FOXO3 protein levels and reduces the dependency of these leukemia cells on PI3K-PKB signaling. This suggests that if p16INK4A is deleted during leukemia development, FOXO3 levels elevate and FOXO3 has to be inactivated by deregulation of the PI3K-PKB pathway to prevent FOXO3-induced cell death.

Increased procoagulant function of microparticles in pediatric inflammatory bowel disease: role in increased thrombin generation.

OBJECTIVES: Patients with inflammatory bowel disease (IBD) have a higher risk for venous thromboembolism compared with non-IBD subjects. The pathogenic mechanisms of the thrombotic events are not fully understood. We investigated levels of circulating microparticles and their influence on thrombin generation in pediatric patients with IBD during active and quiescent disease compared with healthy controls. METHODS: Plasma samples were collected from 33 pediatric patients with Crohn disease (CD), 20 pediatric patients with ulcerative colitis (UC), and 60 healthy controls. Microparticles' procoagulant activity was measured by enzyme-linked immunosorbent assay, and the dependency of thrombin generation on microparticles-derived tissue factor was determined by means of calibrated automated thrombography. RESULTS: The procoagulant function of microparticles was significantly increased in patients with active and inactive CD, and active UC compared with controls. Endogenous thrombin potential was significantly higher in patients with CD and UC compared with controls. A minor influence of microparticles on thrombin generation was only observed for patients with active UC. CONCLUSIONS: Our study shows increased procoagulant function of microparticles in pediatric patients with active and quiescent CD and active UC compared with controls, but demonstrates that they are not a major cause for the higher thrombin generation in pediatric patients with IBD.

Manifestations of juvenile polyposis syndrome in SMAD4 mutation carriers of a kindred.

The autosomal dominantly inherited juvenile polyposis syndrome (JPS) leads to the development of multiple hamartomatous polyps in the gastrointestinal tract and is a precancerous condition. In a large family with a newly identified SMAD4 mutation (c.543delC), we describe the clinical manifestations of JPS. Nine affected SMAD4 mutation-positive family members were screened and treated for manifestations of JPS. Two family members were symptomatic at the time of diagnosis; seven were asymptomatic - independent of the severity of the manifestation. Each mutation carrier presented with colonic juvenile polyps, seven out of nine with additional gastric manifestations. One asymptomatic patient had early gastric cancer; another patient had a villous adenoma with high-grade intraepithelial neoplasia in the colon. Three patients had biliary lesions including a bile duct hamartoma in one and gallbladder polyps in two. Three patients had gastrointestinal vascular malformations. All mutation carriers were affected by JPS. Interestingly, the manifestations and their severity differed considerably between the patients, suggesting secondary factors influencing JPS manifestations such as Helicobacter pylori infection.

Thrombin generation in pediatric patients with Crohn's disease.

BACKGROUND: Patients with inflammatory bowel disease (IBD) have an increased risk of thromboembolic complications. The pathogenesis of IBD is not really clear and a high thrombin activity might contribute to the pathogenesis. We measured thrombin generation by means of calibrated automated thrombography (CAT), a new tool better reflecting overall hemostasis, in children with Crohn's disease (CD) during active and inactive disease and compared it to conventional markers of activity. We wanted to see whether children with CD have a higher potential for thrombin generation and if there is a correlation between hypercoagulability and disease activity. METHODS: Plasma samples were collected from 22 patients with CD and from 61 healthy children. Thrombin generation was measured by means of CAT. The disease activity was estimated using the Pediatric Crohn's Disease Activity Index (PCDAI). In addition, F1+2, TAT, tissue factor pathway inhibitor (TFPI), fibrinogen, prothrombin (FII), antithrombin (AT), erythrocyte sedimentation rate (ESR), platelet count, α2-globulin, and orosomucoide were measured. RESULTS: In all patients we found a significantly higher endogenous thrombin potential (ETP) and higher peak values during active disease. In accordance with this we also found significantly higher mean ETP values during active disease compared with the control group. We observed a significantly positive correlation between PCDAI and thrombin generation parameters. CONCLUSIONS: Our study clearly shows that the active state of CD in children is associated with the potential for high thrombin generation, but this seems to be caused mainly by the inflammatory process and not by a preexisting propensity for high thrombin generation.

Antibiotic-associated hemorrhagic colitis caused by cytotoxin-producing Klebsiella oxytoca.

Klebsiella oxytoca was recently described as the causative organism for antibiotic-associated hemorrhagic colitis (AAHC). It is currently not known if this novel gastrointestinal infection exists in children. AAHC is usually preceded by antibiotic treatment with penicillins, which are frequently prescribed for pediatric patients. In contrast to colitis caused by Clostridium difficile, colitis caused by K oxytoca is usually segmental and located predominantly in the right colon. Patients with AAHC typically present with abdominal pain and almost always bloody diarrhea. We present here the case of an adolescent patient who developed acute abdominal pain and bloody diarrhea after antibiotic treatment for acute urinary infection with amoxicillin-clavulanate. Right-sided colitis was verified by abdominal sonography. Stool culture tested negative for common gastrointestinal pathogens but yielded K oxytoca. Toxin production of the isolated strain was verified in a cell-culture assay. Cessation of the causative antibiotic treatment led to rapid improvement and cessation of bloody diarrhea within 3 days. We report here the first (to our knowledge) pediatric case of K oxytoca infection causing AAHC. Establishing the diagnosis of AAHC by culturing K oxytoca and demonstrating right-sided colitis with noninvasive imaging studies might prevent unnecessary invasive procedures in children with bloody diarrhea.

Survival signaling by C-RAF: mitochondrial reactive oxygen species and Ca2+ are critical targets.

Survival signaling by RAF occurs through largely unknown mechanisms. Here we provide evidence for the first time that RAF controls cell survival by maintaining permissive levels of mitochondrial reactive oxygen species (ROS) and Ca(2+). Interleukin-3 (IL-3) withdrawal from 32D cells resulted in ROS production, which was suppressed by activated C-RAF. Oncogenic C-RAF decreased the percentage of apoptotic cells following treatment with staurosporine or the oxidative stress-inducing agent tert-butyl hydroperoxide. However, it was also the case that in parental 32D cells growing in the presence of IL-3, inhibition of RAF signaling resulted in elevated mitochondrial ROS and Ca(2+) levels. Cell death is preceded by a ROS-dependent increase in mitochondrial Ca(2+), which was absent from cells expressing transforming C-RAF. Prevention of mitochondrial Ca(2+) overload after IL-3 deprivation increased cell viability. MEK was essential for the mitochondrial effects of RAF. In summary, our data show that survival control by C-RAF involves controlling ROS production, which otherwise perturbs mitochondrial Ca(2+) homeostasis.

A retroviral expression system based on tetracycline-regulated tricistronic transactivator/repressor vectors for functional analyses of antiproliferative and toxic genes.

Establishment of stably transfected mammalian cells with conditional expression of antiproliferative or proapoptotic proteins is often hampered by varying expression within bulk-selected cells and high background in the absence of the inducing drug. To overcome such limitations, we designed a gene expression system that transcribes the tetracycline-dependent rtTA2-M2-activator, TRSID-silencer, and selection marker as a tricistronic mRNA from a single retroviral vector. More than 92% of bulk-selected cells expressed enhanced green fluorescent protein or luciferase over more than three orders of magnitude in an almost linear, dose-dependent manner. To functionally test this system, we studied how dose-dependent expression of p27(Kip1) affects proliferation and viability of SH-EP neuroblastoma cells. Low to moderate p27(Kip1) expression caused transient G(0)-G(1) accumulation without reduced viability, whereas high p27(Kip1) levels induced significant apoptosis after 72 hours. This proves that this expression system allows concentration-dependent analysis of gene function and implicates p27(Kip1) as a critical regulator of both proliferation and apoptosis in SH-EP neuroblastoma cells.

Successful treatment of chronic recurrent multifocal osteomyelitis with tumor necrosis factor-alpha blockage.

We describe the case of an 18-year-old girl with chronic recurrent multifocal osteomyelitis (CRMO) over a period of 10 years. She had suffered predominantly from very painful recurrent swelling of her cheeks. Various therapeutic regimens including nonsteroidal antiinflammatory drugs and steroids had shown only a partial or temporary response. Because tumor necrosis factor-alpha-blocking agents have been successfully applied in Crohn's-associated CRMO and the related SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome, tumor necrosis factor-alpha-blocking therapy with infliximab was initiated. Thereafter, apart from 1 mild episode, no additional recurrences were observed during 21 months of follow-up. Infliximab was well tolerated, and steroids were tapered off. Our observation indicates that infliximab may be an effective therapeutic option in CRMO.

Second-line chemotherapy of metastatic malignant melanoma with intravenous treosulfan: a phase II multicentre trial.

The purpose of this multicentre phase II trial was to evaluate time to progression, survival time, rate of objective tumour response and toxicity of second-line intravenous treosulfan chemotherapy in stage IV melanoma patients. Thirty-one patients with measurable stage IV malignant melanoma and prior chemotherapy with a dacarbazine-containing regimen were included. Of this group, 26 patients were evaluable. All patients received treosulfan (8 g/m intravenously on day 1; cycle repeated every 28 days up to six courses). Patients were evaluated for tumour response, survival time and toxicity. No objective responses (complete or partial) were observed. Five patients (19%) showed no change and 21 had progressive disease after treosulfan treatment. Four patients experienced a minor or mixed response. The median time to progression was 1.8 months (95% confidence interval [CI] 1.6-2.1 months) and the median overall survival was 6.5 months (95% CI 3.1-10 months). The 1 year survival rate was 33.9% (95% CI 15.4-52.3%). Leukocytopenia and thrombocytopenia (Common Toxicity Criteria grades 3 and 4) occurred in 15% and 18% of cases, respectively. The non-haematological toxicity of this outpatient regimen was mild. In conclusion, intravenous treosulfan treatment does not induce objective response rates when used as a second-line treatment of metastatic malignant melanoma.