Segmental chromosomal aberrations as the poor prognostic factor in children over 18 months with stage 3 neuroblastoma without MYCN amplification

Introduction

Patients with stage 3 neuroblastoma (NBL) according to International Neuroblastoma Staging System (INSS) without MYCN amplification represent a heterogenous group with respect to disease presentation and prognosis.

Methods

Retrospective analysis of 40 stage 3 patients with NBL without MYCN amplification was performed. The prognostic value of age at diagnosis (under 18 vs over 18 months), International Neuroblastoma Pathology Classification (INPC) diagnostic category and presence of segmental or numerical chromosomes aberrations were evaluated, as well as biochemical markers. Array comparative genomic hybridization (aCGH) for analyzing copy number variations and Sanger sequencing for ALK point mutations were done.

Results

In 12 patients (two patients under 18 months), segmental chromosomal aberrations (SCA) were found and numerical chromosomal aberrations (NCA) were found in 16 patients (14 patients under 18 months). In children over 18 months SCA were more common (p=0.0001). Unfavorable pathology was significantly correlated with SCA genomic profile (p=0.04) and age over 18 months (p=0.008). No therapy failures occurred in children with NCA profile over or under 18 months or in children under 18 months, irrespective of pathology and CGH results. Three treatment failures occurred in the SCA group, in one patient CGH profile was not available. For the whole group at 3, 5 and 10-year OS and DFS were 0.95 (95% CI 0.81-0.99), 0.91 (95% CI 0.77-0.97) and 0.91 (95% CI 0.77-0.97), and 0.95 (95% CI 0.90-0.99), 0.92 (95% CI 0.85-0.98) and 0.86 (95% CI 0.78-0.97), respectively. DFS was significantly lower in the SCA group than in the NCA group (3-years, 5-years, and 10-years DFS 0.92 (95% CI 0.53-0.95), 0.80 (95% CI 0.40-0.95) and 0.60 (95% CI 0.16-0.87) vs 1.0, 1.0 and 1.0, respectively, p=0.005).

Conclusions

The risk of treatment failure was higher in patients with SCA profile, but only in patients over 18 months. All relapses occurred in children having obtained the complete remission, with no previous radiotherapy. In patients over 18 months, SCA profile should be taken into consideration for therapy stratification as it increases the risk of relapse and this group may require more intensive treatment.

Disseminated Juvenile Xanthogranuloma and Hemophagocytic Lymphohistiocytosis Developed During Treatment of Acute Lymphoblastic Leukemia: Case Report

The association between acute lymphoblastic leukemia (ALL), non-Langerhans cell histiocytosis (non-LCH), and hemophagocytic lymphohistiocytosis (HLH), to the best of our knowledge, has not been published to date. Juvenile xanthogranuloma (JXG), as a type of non-LCH, is usually a benign disease limited to the skin. Systemic involvement is rarely reported. The present case report describes a 15-year-old boy diagnosed with disseminated JXG involving skin and bone marrow concurrent with severe symptoms of HLH during ALL therapy. Examination of immunoglobulin heavy chain genes in B-cell precursor leukemic blasts and histiocytes in the skin and bone marrow revealed identical rearrangements, confirming clonal relationship between both diseases. Implementation of corticosteroids, vinblastine, etoposide, cyclosporine, and tocilizumab resulted in partial skin lesion resolution with no improvement of bone marrow function; therefore, hematopoietic stem cell transplantation (HSCT) was eventually performed. The patient's hematological and general status has improved gradually; however, remarkable recovery of skin lesions was observed after empirical antitubercular therapy. Mycobacterium spp. infection should be considered as a possible secondary HLH trigger. Triple association of ALL, non-LCH, and HLH highlights heterogeneity of histiocytic disorders and possible common origin of dendritic and lymphoid cells.

Long-term ultrasound follow-up of intrathyroidal ectopic thymus in children

OBJECTIVE

To present the sonographic follow-up of intrathyroidal ectopic thymus (IET) in children and adolescent patients.

PATIENTS

Out of the 507 children referred to FNAB between 2006 and 2018, 30 (5.9%) pediatric patients (10 females), mean age 5.7 years (1.2-13.8, median 4.9 years) were diagnosed with IET.

METHODS

A retrospective analysis of medical files of patients diagnosed with IET between 2006 and 2018. Assessed data included ultrasound characterisation, elastographic strain ratio (SR) results and hormonal evaluation.

RESULTS

Analysis of thyroid US scans revealed that the mean age at the first thyroid ultrasound was 5.7 (1.2-13.8, median 4.9) years, and at the last US 10.7 (3.7-18, median 10.5) years. The mean time of the IET observation was 59.6 (2-148, median 53.5) months. On US, IET was hypoechoic with multiple linear and punctate echoes, hypovascular, fusiform on longitudinal plane and round or polygonal on an axial plane, more common in the right thyroid lobe (66.7%) and located in the posterior part of the lobes (54.5%), bilateral in two patients and multifocal in one patient. SR of IET was similar to the surrounding normal thyroid tissue. Complete regression of IET was observed in 12/30 patients after a mean time of 81.7 months (median 76.5), at the mean age of 13.7 (9.2-18, median 13.9) years. FNAB was performed in 10/30 and a hemithyroidectomy in 1/30 IET patients. In the FNAB (+) group, patients were younger (5.08 vs 6.08 years) and lesions were larger (0.12 ml vs 0.05 ml) than in the FNAB (-) group. All patients with IET were euthyroid with negative TPOAb and TgAb levels.

CONCLUSION

The reproducibility of unique ultrasound features of IETs allows for safe long-term follow-up of these benign lesions in the majority of pediatric patients: not only monitoring the regression of IET but also screening towards the rare occurrence of a tumor arising from the IET.

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.

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.

Novel insights in ultrasound evaluation of thyroid gland in children with papillary thyroid carcinoma

BACKGROUND

The coincidence of autoimmune thyroiditis (AIT) in patients with papillary thyroid carcinoma (PTC) is ranging between 10 and 58% in the general population.

MATERIAL AND METHODS

In the present study retrospective ultrasound, clinical and autoimmune assessment of 24 patients diagnosed with papillary thyroid carcinoma between 2000-2016 was performed.

RESULTS

The coexistence of PTC and AIT was found in 50% of patients with PTC. Patients were divided into two groups. PTC AIT (+) group involved 12 children at the mean age 14.9 years (range 11-20 years, 9 girls) and PTC AIT (-) 12 children at the mean age 12.9 years (range 7-18 years, 5 girls). Papillary thyroid microcarcinoma (PTMC) was diagnosed in 6 patients (in 5 with AIT). US characteristics of PTC was heterogenous: hypoechogenic with/without increased vascularisation, normoechogenic with halo, with/without microcalcifications. In 70% PTC AIT (+) and in all PTC AIT (-) patients ultrasound analysis revealed that the thyroid tissue of the whole gland was normoechogenic. Local metastases in lymph nodes were found in 40% of PTMC AIT (+).

CONCLUSION

Lack of increased vascularization and microcalcifications and presence of``halo`in the nodule does not exclude malignancy. Due to the presence of lymph node involvement in PTMC in all children with PTC total thyroidectomy should be performed with lymph nodes verification.

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.

Abstract C28: MET receptor downregulation decreases oncogenic properties of cervical carcinoma cells in vitro and in vivo through E-cadherin re-expression and Slug downregulation

Introduction: Cervical carcinoma, despite the development of vaccine, is the second cause of death among women suffering from cancer, especially in low and middle incomes countries. There is currently no effective therapy for advanced cervical cancer and it is important to determine molecular markers, which can help to develop new therapeutic strategies. MET receptor plays an important role during embryonic development, wound healing as well as cancer development and progression. MET is overexpressed in a variety of human cancers increasing their aggressiveness by stimulating tumor cells proliferation, survival and motility. In cervical carcinoma, MET receptor has been shown i) to promote scattering and morphogenesis of tumor cells, ii) to regulate migration and cytoskeleton changes, iii) to translocate of B-catenin transcription factor into the nucleus and iv) to up-regulate cyclin D1 expression.

Objectives: In this study we asked whether downregulation of MET receptor changes cell phenotype into more benign and inhibits tumorigenesis of cervical cancer cells.

Materials and Methods: Cervical carcinoma cell line, HTB-35, was transduced with MET and LacZ shRNA expressing virus. The level of various genes expression was estimated by real-time RT-PCR. Protein expression was evaluated by Western blot. Immunofluorescence and immunohistochemistry staining was used to study the expression of E-cadherin in cells under culture condition and in paraffin tumor section. In in vivo study, cells were injected subcutaneously into NOD-SCID mice (5x106/mouse) and after 4 weeks, tumors were isolated, measured and weighted. All experiments were repeated at least 3 times. For the statistical analysis, P values were assessed with two-tailed Student's t test.

Results: In our study, we showed that silencing of MET receptor decreases proliferation rate by downregulation of cyclin D1 and c-myc. The growth rate between control and MET deficient cells differed significantly for each time point and, after 96 hours of culture, was three times higher for control cells. In MET deficient cells, the expression of cyclin D1 and c-myc was significantly lower in comparison to control cells at mRNA and protein level. Downregulation of MET receptor significantly decreases the expression of epithelial to mesenchymal transition regulating factor, Slug, and increases the expression of E-cadherin, a hallmark of epithelial phenotype in the in vitro study. We observed that downregulation of MET expression dramatically decreases tumor growth in NOD-SCID mice. HTB-35 control cells formed tumors of approximate weight of 1.7 g whereas MET deficient cells formed very small tumors with the mean weight of 0.08 g, or no tumors at all. Moreover, tumors formed by cells with MET receptor downregulation showed the expression of E-cadherin.

Summary: We show that MET receptor downregulation decreases oncogenic properties of cervical carcinoma cells in vitro and in vivo and changes cell phenotype into more epithelial and less aggressive. Thus, inhibition of HGF-MET receptor axis might help in the future to develop new treatment strategies to block cervical carcinoma development and progression.

Acknowledgement: This study was supported by research grants to K.M. from the Polish Ministry of Science and Higher Education NN 401142339, NN 401054839.

Citation Format: Katarzyna Miekus, Marta Pawlowska, Grazyna Drabik, Marcin Majka. MET receptor downregulation decreases oncogenic properties of cervical carcinoma cells in vitro and in vivo through E-cadherin re-expression and Slug downregulation. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C28.

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.

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APPL2 protein levels are elevated in 40% cases of glioblastoma multiforme.

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Overexpression of APPL2 exhibits cytoprotective effects in glioma cells.

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APPL2 depletion reduces survival and transformation abilities of glioma cells.

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Silencing of APPL2 promotes expression of proapoptotic genes HRK and UNC5B.

Causes and consequences of abandoning one-stage bilateral adrenalectomy recommended in primary pigmented nodular adrenocortical disease--case presentation

We present a 7-year-old girl with a 2-year history of decelerated growth rate and cushingoidal obesity, upon admission presenting with fixed hypertension. Cyclic hypercortisolemia with inhibited baseline and post-CRH stimulation ACTH level pointed to primary adrenal hypercortisolemia. Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) showed normal adrenal glands. 131J-labeled cholesterol scintiscan showed a weak but slightly more expressed tracer uptake in the left adrenal gland. Cushing syndrome concomitant with isolated primary pigmented nodular adrenocortical disease (PPNAD) was diagnosed. After hypotensive pretreatment, a left adrenalectomy was performed, resulting in normalization of corticoadrenal function, blood pressure, Cushing features and growth rate. Histopathology confirmed PPNAD. In the course of infection, corticoadrenal function showed absence of adrenal reserve, and adrenal crisis. Hydrocortisone (HC) therapy, followed by HC supplementation was introduced. Four years later, a contralateral adrenalectomy was performed and total HC supplementation was introduced. Causes and consequences of abandoning one-stage bilateral adrenalectomy recommended in PPNAD are reviewed.

Abstract A112: Cell differentiation and downregulation of MET receptor as novel approaches for rhabdomyosarcoma treatment

Introduction: The molecular basis for loss of cell differentiation in the process of carcinogenesis is not well understood but differentiation status of the given tumor strongly influences its progression and metastatic ability and therefore the overall patient survival. Rhabdomyosarcoma (RMS) is one of most frequent soft tissue tumor occurring in children and adolescent. The precise molecular mechanism responsible for the disruption of myogenesis, characteristic for RMS tumors, is not fully understood. Activation of MET receptor has been shown to influence proliferation, survival and migration of RMS cells and MET is rapidly downregulated at the onset of myogenic differentiation. However, the influence of MET receptor on differentiation status of RMS has not been studied at all.

Objectives: We have focused on the induction of differentiation as a novel approach for RMS treatment and looked at the role of MET receptor in this process.

Materials and Methods: The expression of muscles specific genes (MyoD, Myogenin) was evaluated using RT-PCR and western blot in differentiated RMS cells and RMS cells with downregulated MET receptor. Number of apoptotic cells was studied by Annexin V binding assay. In order to study the differentiation potential of MET negative cells, RMS animal model in NOD-SCID mice was developed. We studied tumor morphology (H&E staining), maturity (desmin staining) and proliferation rate (Ki67 staining).

Results: We found that in control cells (poorly maturated RH30 cell line), the expression of MyoD (present in undifferentiated muscle cells) was high whereas during differentiation it decreased. On the other hand, Myogenin expression (present in more matured muscle cells) markedly increased at the same time. We noticed increased number of apoptotic cells in differentiation medium with 2 % of horse serum. We also obtained RMS cell lines with stable downregulation of MET receptor. The expression of differentiation related genes in MET negative cells was similar to serum differentiated RMS cells. MyoD expression was almost completely reduced in these cells. Analysis of tumor lesions formed in NOD-SCID mice showed that tumors with downregulation of MET were much more differentiated and their proliferation rate was much lower. MET negative tumors were also less metastatic in comparison to wild type controls. These data are in concordance with decreased expression of MyoD in vitro and suggest higher differentiation level of MET negative tumors in vivo.

Summary: In this study, for the first time, we have shown that differentiation of RMS cells is connected to the decrease of expression and signaling of MET receptor. These findings might have the significant clinical implication for the treatment of RMS cells because they suggest that induction of differentiation of RMS cells by e.g. blocking MET receptor might have influence on the aggressiveness/metastatic potential of these tumors.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A112.

Abstract C160: Hepatocyte growth factor-MET receptor axis as a potential target for blocking cervical carcinoma metastasis into bones and bone marrow

Introduction: Cervical carcinoma (CC) is one of the major causes of death among women suffering from tumor. The highest mortality is observed in the group of patients with late diagnosis and a metastatic disease. HGF/MET axis has been shown to be an important modulator of tumor cells motility and invasion. Recently we have shown that HGF/MET axis synergizes with SDF-1/CXCR4 axis in stimulating CC cell chemotaxis and activation of various intracellular pathways.

Objectives: In this study we focused on the role of MET receptor in CC.

Materials and Methods: CC cell lines (HeLa, HTB34 and HTB35) were transduced with MET shRNA and LacZ shRNA expressing virus and subsequently selected with blasticidin. To check receptors expression real-time PCR and flow cytometry was used. Migration was checked by chemotaxis and invasion assays. The level of various protein phosphorylation was estimated by western blot. NOD-SCID mice were used in in vivo experiments.

Results: Morphological assessment of MET negative cell lines revealed that one of them, HTB 35, has changed the morphology and cells became on average 2 times smaller than their control counterparts. The cells were also characterized by different proliferation rate when cultured under stressed conditions. Low oxygen (2%) or low serum condition caused strong > 50% inhibition of growth rate. Moreover, the migration and transmigration (through extracellular matrix proteins) toward HGF of all three cell lines with downregulated of MET was strongly inhibited. CC cells with downregulation of MET receptor showed inhibition of activation of several intracellular signaling pathways including RAS-MAPK, JAK-STAT and PI3K-AKT. We also performed in vivo study using NOD-SCID mice. All three cell lines were able to growth in these mice, however to different degree. HeLa and HTB 35 formed large tumors whereas HTB 34 formed small tumors. Growth of HeLa and HTB 34 cells was not inhibited by blocking MET receptor expression. However, HTB 35 tumor cells that lacked MET expression formed only very small tumors or no tumors at all. Cells present in these tumors were much more differentiated and matured. Moreover they formed structures similar to osteocytes and chondrocytes.

Summary: For the first time we shown here that HGF-MET axis activation significantly influences metastatic behavior of cervical carcinoma in vitro and in vivo and inhibition of this axis could be used as the new therapeutic strategy to block cervical carcinoma metastasis into bones and bone marrow.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C160.

Detection of isolated tumour cells in the blood and bone marrow of patients with gastric cancer by combined sorting, isolation and determination of MAGE-1, -2 mRNA expression

The detection of isolated (circulating or disseminated) tumour cells (ITC) in patients with cancer requires very sensitive methods, as such cells are very rare. In the present study, the method that combines the negative isolation of CD45- leukocytes from the blood and bone marrow of patients with gastric cancer by flow cytometry, followed by the positive isolation of single cytokeratin-positive (CK+) cells by a Laser Capture Microdissection System for the determination of MAGE-1, -2 mRNA expression was used to detect ITC. This study shows that this method is highly sensitive as it allows to determine beta-actin-mRNA expression in a single CK+ cell. Using > or =5 CK+ cells as a cut-off level, the MAGE-1 mRNA expression was detected in 100% of CK+ cells in the peripheral blood and in 75% of bone marrow samples of patients with gastric cancer. The MAGE-2 mRNA expression was observed in 40 and 58% of samples, respectively. Furthermore, an analysis of primary tumours and locoreginal lymph nodes with respect to the mRNA expression of the two genes showed that MAGE-1 mRNA expression was detected in 88% of the primary tumours and in 67% of the lymph node samples, whereas the MAGE-2 mRNA expression was observed in 72 and 67% of the cases, respectively. Thus, the method described here allows the precise and sensitive determination of tumour-associated gene expression in single ITC present in the blood and bone marrow of patients with gastric cancer.

The effects of preoperative chemotherapy on isolated tumour cells in the blood and bone marrow of gastric cancer patients

Recent studies in breast cancer suggest that monitoring the isolated tumour cells (ITC) may be used as a surrogate marker to evaluate the efficacy of systemic chemotherapy. In the present study, we have investigated the effects of preoperative chemotherapy on ITC in the blood and bone marrow of patients with potentially resectable gastric cancer. After sorting out the CD45-positive cells, the presence of ITC defined as cytokeratin-positive cells was examined before and after preoperative chemotherapy. The patients received two courses of preoperative chemotherapy with cisplatin (100 mg m⁻², day 1) and 5-fluorouracil (1000 mg m⁻², days 1–5), administered every 28 days. Fourteen of 32 (44%) patients initially diagnosed with ITC in blood and/or bone marrow were found to be negative (responders) after preoperative chemotherapy (P<0.01). The incidence of ITC in bone marrow was also significantly (P<0.01) reduced from 97 (31 of 32) to 53% (17 of 32). The difference between patients positive for ITC in the blood before (n=7, 22%) and after (n=5, 16%) chemotherapy was statistically insignificant. The overall 3-year survival rates were 32 and 49% in the responders and non-responders, respectively (P=0.683). These data indicate that preoperative chemotherapy can reduce the incidence of ITC in patients with gastric cancer.

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.

Immunophenotype of isolated tumour cells in the blood, bone marrow and lymph nodes of patients with gastric cancer

Immunophenotype of isolated (disseminated or circulating) tumour cells (ITC) in the blood, bone marrow and lymph nodes were studied in patients with gastric cancer. Coexpression of metalloproteinases inducer (EMMPRIN), chemokine receptors (CCR6, CXCR4) and adhesion molecules (Ep-CAM, CD44) was determined on cytokeratin positive (CK+) cells in CD45- cell population sorted out from the blood and/or bone marrow. Eight cytospin samples of blood and 69 samples of bone marrow containing CK+ cells from patients with gastric cancer were included into study. Expression of EMMPRIN and CCR6 were noted in a half of CK+ samples (of blood/bone marrow) whereas the expression of CXCR4 and Ep-CAM was much lower. Analysis of paired data of these determinants expression on CK+ cells showed no association between them. Expression of EMMPRIN, Ep-CAM, CCR6, CCR7, CXCR1, and CXCR4 on ITC in lymph nodes was determined by flow cytometry. In 18 lymph nodes (out of 36 assayed) CK+ cells were found. The expression of CCR6 and Ep-CAM on CK+ cells was observed in almost all studied lymph nodes, CXCR1--in half of them. The expression of EMMPRIN and CCR7 cells was lower. These results suggest that ITC of gastric cancer express variably several molecules that may be involved in metastasis formation.

Lymphocyte populations in lymph nodes in different histological types of Hodgkin's disease in children

Proliferating Reed-Sternberg and Hodgkin's cells within the lymph node in Hodgkin's disease (HD) affect the surrounding cells, which results in alterations of the proportion between T and B lymphocytes and the activation of these cells. The purpose of this study was to assay the changes within lymphocyte populations in lymph nodes in different types of HD. The lymph nodes of 10 children with nonmalignant, reactive changes, and 31 children with HD of the following types: mixed cellularity (MC; 11 cases), nodular sclerosis (NS; 17 cases) and lymphocyte depletion (LD; 3 cases) were included in the study. The percentage of T lymphocytes (CD3+), B lymphocytes (CD22+), T cell (CD4+ and CD8+) and B cell subsets (kappa+ and lambda+ light chain) were assayed with flow cytometry. The ratio of T:B lymphocytes in reactive lymph nodes and in NS type of HD was similar. An increase of the T cell percentage (resembling an increase of the CD4+ subset) and a decrease of B cells resulted in a high ratio of T:B and was noted in the MC and LD types of HD. These HD types were associated with marked changes in lymphocytes within the lymph node, which suggested a different effect of proliferating Reed-Sternberg and Hodgkin cells in HD on the surrounding cells.

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.

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.

Effects of humanization by variable domain resurfacing on the antiviral activity of a single-chain antibody against respiratory syncytial virus

HNK20 is a mouse monoclonal IgA that binds to the F glycoprotein of respiratory syncytial virus (RSV) and neutralizes the virus, both in vitro and in vivo. The single-chain antibody fragment (scFv) derived from HNK20 is equally active and has allowed us to assess rapidly the effect of mutations on affinity and antiviral activity. Humanization by variable domain resurfacing requires that surface residues not normally found in a human Fv be mutated to the expected human amino acid, thereby eliminating potentially immunogenic sites. We describe the construction and characterization of two humanized scFvs, hu7 and hu10, bearing 7 and 10 mutations, respectively. Both molecules show unaltered binding affinities to the RSV antigen (purified F protein) as determined by ELISA and surface plasmon resonance measurements of binding kinetics (Ka approximately 1x10(9) M-1). A competition ELISA using captured whole virus confirmed that the binding affinities of the parental scFv and also of hu7 and hu10 scFvs were identical. However, when compared with the original scFv, hu10 scFv was shown to have significantly decreased antiviral activity both in vitro and in a mouse model. Our observations suggest that binding of the scFv to the viral antigen is not sufficient for neutralization. We speculate that neutralization may involve the inhibition or induction of conformational changes in the bound antigen, thereby interfering with the F protein-mediated fusion of virus and cell membranes in the initial steps of infection.

[Complications of endoscopic sphincterotomy]

The aim of the study is an analysis of the complications among the patients who underwent endoscopic sphincterotomy. In years 1991-1996 in our Department 412 patients underwent endoscopic sphincterotomy. Bile ducts stones, acute bile pancreatitis, papilla Vateri stricture and the postoperative bile fistula were the indications for the procedure. Complications occurred in 37 patients (12 of them were operated on). One patient died due to duodenal perforation. GI bleeding, acute pancreatitis, common bile duct perforation, recurrence of the stricture and missing the concrement in the duct were the main complications. Endoscopic sphincterotomy remains the recommended method in describe cases.

Intranasal monoclonal IgA antibody to respiratory syncytial virus protects rhesus monkeys against upper and lower respiratory tract infection

Respiratory syncytial virus (RSV), the major cause of lower respiratory tract disease in infants, is thought to infect the upper airways before spreading to the lower respiratory tract. A rhesus monkey model of RSV infection after upper airway inoculation was used to test the protective effect of intranasal treatment with HNK20, a mouse monoclonal IgA antibody against RSV F glycoprotein. HNK20 was administered once daily for 2 days before RSV challenge and 4 days after challenge. Treatment with 0.5 mg/kg HNK20 reduced viral shedding in the nose, throat, and lungs by 3-4 log10/mL (P < or = .002). All monkeys developed RSV neutralizing antibody in serum, even in the absence of detectable viral replication. Neutralizing concentrations of monoclonal antibody remained in nasal secretions for > 1 day after treatment. These results suggest that nose-drop application of monoclonal antibody could provide convenient and effective protection against RSV infection in human infants at risk of severe lower respiratory tract disease.