Chlorination of N-acetyltyrosine with HOCl, chloramines, and myeloperoxidase-hydrogen peroxide-chloride system

N-acetyl-L-tyrosine (N-acTyr), with the alpha amine residue blocked by acetylation, can mimic the reactivity of exposed tyrosyl residues incorporated into polypeptides. In this study chlorination of N-acTyr residue at positions 3 and 5 in reactions with NaOCl, chloramines and the myeloperoxidase (MPO)-H2O2-Cl- chlorinating system were invesigated. The reaction of N-acTyr with HOCl/OCl- depends on the reactant concentration ratio employed. At the OCl-/N-acTyr (molar) ratio 1:4 and pH 5.0 the chlorination reaction yield is about 96% and 3-chlorotyrosine is the predominant reaction product. At the OCl-/ N-acTyr molar ratio 1:1.1 both 3-chlorotyrosine and 3,5-dichlorotyrosine are formed. The yield of tyrosine chlorination depends also on pH, amounting to 100% at pH 5.5, 91% at pH 4.5 and 66% at pH 3.0. Replacing HOCl/OCl- by leucine/chloramine or alanine/chloramine in the reaction system, at pH 4.5 and 7.4, produces trace amount of 3-chlorotyrosine with the reaction yield of about 2% only. Employing the MPO-H2O2-Cl- chlorinating system at pH 5.4, production of a small amount of N-acTyr 3-chloroderivative was observed, but the reaction yield was low due to the rapid inactivation of MPO in the reaction system. The study results indicate that direct chlorination of tyrosyl residues which are not incorporated into the polypeptide structure occurs with excess HOCl/OCl- in acidic media. Due to the inability of the myeloperoxidase-H2O2-Cl- system to produce high enough HOCl concentrations, the MPO-mediated tyrosyl residue chlorination is not effective. Semistable amino-acid chloramines also appeared not effective as chlorine donors in direct tyrosyl chlorination

Ultrasound variants of autoimmune thyroiditis in children and adolescents and their clinical implication in relation to papillary thyroid carcinoma development

Background The prevalence of autoimmune thyroiditis (AIT) and papillary thyroid carcinoma (PTC) is rising in children and adolescents, and the coincidence of AIT and PTC is as high as 6.3-43%. Objective To investigate the ultrasound manifestation of AIT in relation to PTC development in paediatric patients. Patients 179 paediatric patients (133 females), mean (SD) age: 13.9 (3.03) years diagnosed with AIT and referred for ultrasound evaluation. Eight patients were diagnosed with PTC (6 females). Methods Retrospective analysis of thyroid ultrasound scans of patients diagnosed with AIT. Thyroid and autoimmune status was assessed based on TSH, fT4, fT3 and increased aTPO and/or aTG and/or TRAB levels. In patients with PTC, total thyroidectomy was performed. Results Analysis of thyroid US scans revealed that the following five ultrasound variants of AIT were observed in 179 patients: the most common in 35.2%-diffuse thyroiditis with hypoechogenic background and normoechogenic parenchyma, in 30.2%-diffuse thyroiditis with irregular background, in 18.9% nodular variant with normoechogenic background, in 11.7%-micronodulations and in 3.9%-diffuse hypoechogenic background. Eight cases of PTC were diagnosed in nodular variant of AIT with normoechogenic irregular background. Conclusion Patients with AIT and nodular variant with normoechogenic irregular background of the thyroid gland on US scans are in the risk group of developing PTC and should be followed up with regular neck US assessment

CD44+ cytokeratin-positive tumor cells in blood and bone marrow are associated with poor prognosis of patients with gastric cancer

Background The phenotypic heterogeneity of circulating tumor cells (CTC) in peripheral blood and disseminated tumor cells (DTC) in bone marrow is an important constraint for clinical decision making. Here, we investigated the implications of two different subpopulations of these cells in gastric cancer (GC). Methods GC patients (n=228) who underwent elective gastric resections were prospectively examined for CTC/DTC. The cells obtained from peripheral blood and bone marrow aspirates were sorted by flow cytometry and CD45- cells expressing cytokeratins (8, 18, and 19) and CD44 were identified by immunofluorescent double staining. Results Ninety-three (41%) patients had cytokeratin-positive tumor cells in either blood or bone marrow, while cells expressing CD44 were found in 22 (10%) cases. CK+CD44+ cells were significantly more common among patients with distant metastases (50 vs 19%, P=0.001), while no such correlations were demonstrated for CK+CD44- cells. Detection of CK+CD44+ cells, but not CK+CD44-, was associated with significantly shortened survival. Moreover, the Cox proportional hazards model identified CK+CD44+ cells as a negative prognostic factor with an odds ratio of 2.38 (95% CI 1.28-4.41, P=0.006). Conclusion CD44+ phenotype of cytokeratin-positive cells in blood and bone marrow is an independent prognostic factor in patients with gastric cancer

MET receptor is a potential therapeutic target in high grade cervical cancer

Cervical cancer is one of the leading causes of death among women suffering from tumors. Current treatment options are insufficient. Here, we investigated the MET receptor as a potential molecular target in advanced cervical cancer. Downregulation of MET receptor expression via RNA interference in different cervical carcinoma cell lines dramatically decreased tumor growth and forced tumor differentiation in vivo. MET receptor silencing also led to a dramatic decrease in cell size and a decrease in proliferation rate under normal and stress conditions. MET receptor downregulation also resulted in decreased cyclin D1 and c-myc levels but did not increase apoptosis. Subsequent experiments showed that downregulation of the MET receptor decreased the expression of a key regulator of the epithelial-to-mesenchymal transition, SLUG. and increased the expression of E-cadherin, a hallmark of the epithelial phenotype. Moreover, MET downregulation impairs expression and signaling of CXCR4 receptor, responsible for invasive phenotype. Taken together, our results strongly suggest that the MET receptor influences the oncogenic properties of cervical carcinoma cells in vitro and in vivo. These findings highlight a unique role of the MET receptor in cervical carcinoma cells and indicate the MET receptor as a potential therapeutic target for advanced cervical carcinoma

Fetus in fetu : a medical curiosity-considerations based upon an intracranially located case

Introduction “Fetus in fetu” (FIF) is defined as the abnormal monozygotic twin inside the body of its “host twin.” Intracranial FIFs are extremely rare. Case presentation A male premature newborn was admitted to the hospital due to a large intracranial tumor diagnosed in the 31st week of gestation. The child died before surgical treatment because of failure of the respiratory system due to fetal respiratory distress syndrome. During general autopsy, a large intracranial tumor with four relatively well-developed limbs was found. Microscopically, apart from relatively well-formed musculoskeletal structures of limbs that were covered with skin, there were haphazardly distributed different tissues or fragments of organs. However, various neuroectodermal derivatives were dominant. Conclusion We believe that intracranial FIFs, theoretically with poor prognosis, can be successfully curable in cases revealed prenatally, provided that optimal treatment is introduced and the achievement of proper pulmonary maturity of the host is accomplished prior to the operation of the tumor

Multifunctional protein APPL2 contributes to survival of human glioma cells

Some endocytic proteins have recently been shown to play a role in tumorigenesis. In this study, we demonstrate that APPL2, an adapter protein with known endocytic functions, is upregulated in 40% cases of glioblastoma multiforme, the most common and aggressive cancer of the central nervous system. The silencing of APPL2 expression by small interfering RNAs (siRNAs) in glioma cells markedly reduces cell survival under conditions of low growth factor availability and enhances apoptosis (measured by executor caspase activity). Long‐term depletion of APPL2 by short hairpin RNAs (shRNAs), under regular growth factor availability, suppresses the cell transformation abilities, assessed by inhibited colony formation in soft agar and by reduced xenograft tumor growth in vivo. At the molecular level, the negative effect of APPL2 knockdown on cell survival is not due to the alterations in AKT or GSK3β activities which were reported to be modulated by APPL proteins. Instead, we attribute the reduced cell survival upon APPL2 depletion to the changes in gene expression, in particular to the upregulation of apoptosis‐related genes, such as UNC5B (a proapoptotic dependence receptor) and HRK (harakiri, an activator of apoptosis, which antagonizes anti‐apoptotic function of Bcl2). In support of this notion, the loss of glioma cell survival upon APPL2 knockdown can be rescued either by an excess of netrin‐1, the prosurvival ligand of UNC5B or by simultaneous silencing of HRK. Consistently, APPL2 overexpression reduces expression of HRK and caspase activation in cells treated with apoptosis inducers, resulting in the enhancement of cell viability. This prosurvival activity of APPL2 is independent of its endosomal localization. Cumulatively, our data indicate that a high level of APPL2 protein might enhance glioblastoma growth by maintaining low expression level of genes responsible for cell death induction

Circulating tumour cells and survival of patients with gastric cancer

Background: The prognostic significance of the presence of tumour cells in the blood of gastric cancer patients remains unclear. Their occurrence and its association with the stage of disease and long-term survival was determined. Patients and Methods: Fifty-seven patients with stage I-IV gastric cancer were divided into two groups: these with and these without circulating tumour cells that were identified as cytokeratin positive (CK+) cells among CD45– cells (obtained by sorting of CD45+ leukocytes). Results: Tumour cells were detected prior surgery in the peripheral blood of 54.4% patients but no clear association with the stage of disease was observed. After gastrectomy detection rate was 21.1%. There was no significant difference in the 5-year survival of patients, with or without CK+ in the blood. Conclusion: The presence of circulating tumour cells is of no prognostic value in patients with resectable gastric cancer

Follow-up of parenchymal changes in the thyroid gland with diffuse autoimmune thyroiditis in children prior to the development of papillary thyroid carcinoma

Purpose To present the outcomes of ultrasound (US) follow-ups in children with autoimmune thyroid disease who did not have a thyroid nodule on admission but developed papillary thyroid carcinoma (PTC) and to characterize the parenchymal changes in the thyroid gland prior to the development of PTC. Methods A retrospective thyroid US scan review of 327 patients diagnosed with AIT was performed. Forty patients (40/327, 12.2%) presented nodular AIT variant with a normoechogenic background. Eleven patients (11/327, 3.4%, 11/40, 27.5%) presenting this variant were diagnosed with PTC (nine females-mean age 15.3 years; two males aged 11 and 13 years). In five of 11 patients, the suspicious nodule that was later confirmed to be PTC was detected on the initial US at presentation. For the remaining six females (6/11) who developed PTC during the follow-up, we retrospectively analysed their US thyroid scans and these patients were selected for analysis in this study. Results On admission, the US evaluation revealed an enlarged normoechogenic thyroid gland in three patients and a hypoechogenic thyroid gland with fibrosis as indicated by irregular, chaotic hyperechogenic layers in three patients. No thyroid nodules were identified. Ultrasound monitoring revealed increasing echogenicity of the thyroid parenchyma during the follow-up. PTC developed in a mean time of 4.6 years (1 9/12-7 4/12 years) since referral to the outpatient thyroid clinic and 2.9 years (6/12-6 9/12) since the last nodule-free US thyroid scan. Conclusions Sonographic follow-up assessments warrant further exploration as a strategy to determine PTC susceptibility in the paediatric population