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OBJECTIVE: Description of newborn with early prenatal diagnosis of sacrococcygeal teratomia. Desing: Case report. SETTING: Department of Obstetrics and Gynecology, 2nd Faculty of Medicine and Faculty Hospital Motol Prague. CASE REPORT: In this case report a term neonate with a massive sacrococcygeal teratoma was delivered by a cesarean section (approach by Geppert) with an intrapartal relieving punction of the tumor. It was a type II SCT with both pelvic end extracorporal component with a size of 60×35 centimeters. The tumor was completely resected during the first day of life and was followed by a normal function of lower extremities, normal bowel function and only transitional urinary tract symptoms. CONCLUSION: A sacrococcygeal teratoma (SCT) is the most common congenital tumor in newborns with reported incidence of 1:35000-40000 live births affecting more frequently females (4:1). This germinal tumor is either benign (mature) or malignant (immature), mature types are more common in neonates. A SCT is usually diagnosed by prenatal ultrasound, magnetic resonance is performed to characterize its size and content, type of tumor (type I-IV Altman classification) and relation to surrounding tissues. Preemptive early delivery by cesarean section is recommended when the tumor exceeds the diameter of 5 centimeters to avoid complications during vaginal delivery (rupture, bleeding etc.). The primary treatment of SCT is an early surgical resection with a complete resection of the coccyx („en bloc“ resection), malignant tumors are indicated for adjuvant chemotherapy. Long term complications can be urinary tract or bowel dysfunctions, lower extremity muscle weakness or paralysis and recurrence of the tumor with potential malignancy.

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PURPOSE: Crohn's disease (CD) belongs to chronic disorders with unpredictable disease course. The aim of this study was to identify how genetic testing (NOD2/CARD15) can be used in patients with CD to predict the need for surgical treatment (to define an aggressive type of disease where the patient can profit from early surgery). METHODS: The patients who were tested genetically had undergone a surgery due to CD at the Department of Surgery University Hospital Brno Bohunice between 2010 and 2016. The control group consisted of patients with CD who had been diagnosed with CD at least 5 years prior to the testing and had not required any surgical intervention. The second control group was healthy subjects. RESULTS: In total, there were 117 operated patients for CD, 77 patients with CD that had not undergone surgery for CD and 30 healthy subjects. For patients with at least one genetic mutation, the risk of the necessity of surgical treatment of CD is 1.96 times higher than for patients with no mutation. Patients with two or more mutations were generally operated on at a younger age, in a shorter time after being diagnosed and each patient had a partial resection of the ileum. CONCLUSION: The group of operated patients with CD had a significantly higher distribution of at least one genetic mutation as opposed to the non-operated group. In patients with two or more mutations, the disease course was more aggressive. This group of patients might profit from the conservative top-down or early surgical therapy.

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Testicular germ cell tumors (TGCTs) are highly sensitive to cisplatin­based chemotherapy. Nevertheless, there are metastatic tumors that do not completely respond to front­line chemotherapy. For these tumors, surgical resection of residual masses is necessary to achieve long­term disease control. Resected tissues represent valuable clinical material, which may be used for the engraftment into immunocompromised mice to produce patient­derived xenografts (PDXs). They typically maintain similarities to the parental tumors and therefore serve as more realistic preclinical models. Moreover, a correlation between PDX treatment outcomes and clinical response to chemotherapy has been previously described. The aim of the present study was to establish and characterize TGCT patient­derived xenografts. These originated from retroperitoneal lymph node metastases infiltrated with TGCTs following previous cisplatin­based chemotherapy, in order to analyze novel treatment options for cisplatin­resistant testicular tumors. We generated two testicular patient­derived xenograft models in SCID beige male mice. Immunohistochemical analyses demonstrated that histological characteristics of the primary tumor were not retained, and transformation into lymphoma, and eventually plasmocytoma, was observed. A potential explanation for the lymphoma transformation observed in PDXs may include tumor­infiltrating lymphocytes (TILs) in xenografted samples of patients, which are transformed following engraftment into immunodeficient recipient mice. Based on these data, we indicated that lymphomagenesis prevention and terminal differentiation represent new challenges in the establishment of PDX models derived from patients with germ cell tumors.

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BACKGROUND: Recent evidence in cancer research, developed the notion that malignant tumors consist of different subpopulations of cells, one of them, known as cancer stem cells, being attributed many important properties such as enhanced tumorigenicity, proliferation potential and profound multidrug resistance to chemotherapy. Several key stem cells markers were identified in colon cancer. In our study we focused on the aldehyde dehydrogenase type 1 (ALDH1) expression in colon cancer-derived cell lines HT-29/eGFP, HCT-116/eGFP and LS-180/eGFP, and its role in the chemoresistance and tumorigenic potential. METHODS: The effect of pharmacological inhibition of ALDH activity by diethylaminobenzaldehyde (DEAB) and also effect of molecular inhibition by specific siRNA was evaluated in vitro in cultures of human colorectal cell lines. The expression level of different isoenzymes of aldehyde dehydrogenase was determined using qPCR. Changes in cell biology were evaluated by expression analysis, western blot and apoptosis assay. The efficiency of cytotoxic treatment in the presence of different chemotherapeutic drugs was analyzed by fluorimetric assay. Tumorigenicity of cells with specific ALDH1A1 siRNA was tested in xenograft model in vivo. RESULTS: Treatment by DEAB partially sensitized the tested cell lines to chemotherapeutics. Subsequently the molecular inhibition of specific isoforms of ALDH by ALDH1A1 or ALDH1A3 siRNA led to sensitizing of cell lines HT-29/eGFP, HCT-116/eGFP to capecitabine and 5-FU. On the model of athymic mice we observed the effect of molecular inhibition of ALDH1A1 in HT-29/eGFP cells by siRNA. We observed inhibition of proliferation of subcutaneous xenografts in comparison to control cells. CONCLUSION: This research, verifies the significance of the ALDH1A isoforms in multidrug resistance of human colorectal cancer cells and its potential as a cancer stem cell marker. This provides the basis for the development of new approaches regarding the treatment of patients with colorectal adenocarcinoma and potentially the treatment of other tumor malignancies.

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Based on our experimental data, we aimed to emphasise the perspectives of the use of mesenchymal stromal cells (MSC) in the cancer gene therapy. On the other hand, we would like to point out factors which should be taken into consideration at their clinical use. In this review we define MSC as unique targets for targeted therapy. We proved the efficacy of experimental therapeutic approach utilising enzymatic conversion of non-toxic prodrug into chemotherapeutic by engineered MSC, and we observed significant cytotoxic effect in many preclinical models including metastatic disease. Treatment was enabled by affinity of MSC to tumour tissue and subsequent delivery of therapeutic molecule into the tumour. We also observed decreased efficacy of cell-mediated gene therapy on chemoresistant tumour cells. Moreover MSC can exert a supportive effect on tumour cells as well as to decrease the efficacy of conventional treatment. Besides obvious unique benefits connected to the use of MSC we pointed also to possible risks associated with their clinical application (Ref. 24).

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Cell-based anticancer therapy using mesenchymal stromal cells (MSCs) engineered to express therapeutic genes has a potential to target the cancer cells in vivo. Metastatic dissemination of melanoma remains a serious problem in the treatment. In our previous work we used MSCs overexpressing gene for tumor necrosis factor α (TNFα; MSCs/TNFα), and we achieved inhibition of melanoma xenograft growth when engineered MCSs/TNFα were coinjected with tumor cells subcutaneously. The TNFα as a pleiotropic cytokine induces apoptosis of tumor cells, creates "tumor resistant" microenvironment, enhances immune response and can have tumor destructive capacity in selected tumor types, especially in tumors of mesodermal origin.In this study we investigated the possibility of intravenously administered MCSs/TNFα to inhibit metastatic spread of A375 melanoma cells in the lungs. We confirmed elevated expression of TNFα transgene in the lung tissue 20 days after MCSs/TNFα intravenous infusion. We also documented that constitutive expression of TNFα transgene is able to neutralize the supportive effect of MSCs on melanoma cells growth. Metastatic spread of A375 melanoma cells in the lung was inhibited approximately to 50% after MCSs/TNFα i.v. administration in comparison to control group with parental MSCs supporting tumor growth. In conclusion, engineered MCSs/TNFα administered intravenously did not demonstrate significant antitumor effect against experimental melanoma lung metastases in this model settings.

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Benign and malignant tumours are known to express various factors inducing lymphangiogenesis. Despite their different biological behaviour, salivary pleomorphic adenomas (PA) and adenoid cystic carcinomas (SACC) show similar lymphatic network. Authors compare density of lymphatic network in these tumours. The retrospective study included 20 SACC and 20 PA from salivary tumours. Lymphatic vessel density (LVD) was identified using D2-40 antibody and counted. In SACC, intratumoral, respectively peritumoral, lymphatic vessels were identified in 100 %, respectively 93.8 %, of cases. The intratumoral and peritumoral LVD did not significantly differ from each other. However, they both were higher than normal parenchyma density. In PA, intratumoral LVD, with a single exception, revealed values of 0 and 1. The intratumoral was found to be lower than peritumoral density. The LVD in healthy gland, similar to peritumoral one, was significantly higher than intratumoral values. Direct comparison showed intratumoral and peritumoral LVD in PA to be lower than in SACC. This study comparing LVD in PA and SACC revealed higher values in SACC, outnumbering those in healthy salivary parenchyma and PA. It suggests the capability of this biologically aggressive neoplasm to induce lymphangiogenesis.

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Epithelial-to-mesenchymal transition (EMT) significantly affects the risk of metastasising in breast cancer. Plasticity and reversibility of EMT suggest that epigenetic mechanisms could be the key drivers of these processes, but little is known about the dynamics of EMT-related epigenetic alterations. We hypothesised that EMT, mediated by autocrine and paracrine signals, will be accompanied by changes in DNA methylation profiles. Therefore, conditioned medium from adipose tissue-derived mesenchymal stromal cells was used for induction of EMT in human breast cancer SK-BR-3 cell line. EMT-related morphological alterations and changes in gene expression of EMT-associated markers were assessed. To reverse EMT, 20 nm size gold nanoparticles (AuNPs) synthesized by the citrate reduction method were applied. Finally, DNA methylation of LINE-1 sequences and promoter methylation of TIMP3, ADAM23 and BRMS1 genes were quantitatively evaluated by pyrosequencing. Despite the presence of EMT-associated morphological and gene expression changes in tumour cells, EMT induced by adipose tissue-derived mesenchymal stromal cells had almost no effect on LINE-1 and gene-specific DNA methylation patterns of TIMP3, ADAM23 and BRMS1 genes. Although treatment for 24, 48 or 72 hours with 20 nm AuNPs at a concentration of 3 µg/ml slightly decreased gene expression of EMT-associated markers in SK-BR-3 cells, it did not alter global or gene-specific DNA methylation. Our results suggest that changes in DNA methylation are not detectable in vitro in early phases of EMT. Previously published positive findings could represent rather the sustained presence of potent EMT-inducing signals or the synergistic effect of various epigenetic mechanisms. Treatment with AuNPs slightly attenuated EMT, and their therapeutic potential needs to be further investigated.

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Malignant melanoma represents a neoplasm stemming from melanocytes or the cells that develop from melanocytes. Melanocytes, pigment-producing cells, arise from the neural crest and migrate to their final destinations in the skin, uveal tract, meninges, and mucosa. Most melanocytes are found at the epidermal-dermal junction of the skin, and the vast majority of melanocytes arise from cutaneous sites. Cancerous growths develop when unrepaired DNA damage to skin cells (most often caused by ultraviolet radiation from sunshine or tanning beds) triggers mutations (genetic defects) that lead the skin cells to multiply rapidly and form malignant tumours. Malignant tumours consist of heterogeneous populations of tumour cells. Cancer stem cells (CSC) represent a population of cells within a tumour with highly tumorigenic and chemoresistant properties. These cells may be identified by the expression of CSC markers and also by functional assays as tumour-initiating properties in vivo, high aldehyde dehydrogenase activity tested by Aldefluor assay. There are several key stem cells markers specified for malignant melanoma: CD20, CD133, ABCB5, CD271 and ALDH1A. The review provides a detailed overview of risk factors, diagnosis, treatment possibilities and specific properties of cancer stem cells in malignant melanoma.

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INTRODUCTION: Crohn´s disease (CD) highly affects a patient´s quality of life. The aim of the study was to find out the impact of surgery on the quality of life (QoL) in CD patients and factors affecting their postoperative QoL. METHODS: 90 patients with CD who underwent surgery (bowel resection) filled out an EORTC QLQ-CR29 questionnaire preoperatively and again after the surgical procedure. RESULTS: 77% of the patients experienced a positive change (p<0.001), 22% negative and 11% no change. CONCLUSION: In this cohort, we proved that surgical treatment improves the overall QoL in patients with CD. To determine factors which affect postoperative QoL, more patients need to be enrolled in future studies.Key words: Crohn´s disease - quality of life - surgery - bowel resection - Czech cohort.

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Mesenchymal stromal cells (MSC) exhibit beneficial properties to serve as cellular vehicles for enzyme/prodrug cancer gene therapy approaches. We have previously shown that engineered human adipose tissue-derived MSC in combination with non-toxic prodrug mediated substantial cytotoxic and antitumor effect. The aim of this study was to develop advanced 3D cultivation method to serve for modelling of the therapeutic outcome in vitro. We have used engineered MSC expressing fusion transgene cytosine deaminase::uracilphosphoribosyltransferase (CD-MSC) in combination with prodrug 5-fluorocytosine (5FC). This therapeutic regimen designated CD-MSC/5FC was combined with the human melanoma cells A375 or EGFP-A375 in both standard monolayer culture and 3-dimensional (3D) multicellular nodules. The extent of cytotoxicity was evaluated by standard viability assay MTS, ATP-based luminescence assay, fluorimetric test, measurement of Caspase-3/7 activation and DNA laddering. The data have shown that the extent of cytotoxic bystander effect mediated by CD-MSC/5FC is significantly lower in 3D culture conditions. However, these data better recapitulate the therapeutic efficiency as observed previously in vivo. We suggest here to use the 3D multicellular culture conditions for better prediction of the therapeutic outcome in mouse xenograft models.

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Mesenchymal stromal cells (MSC) can be exploited as cellular delivery vehicles for the enzymes converting non-toxic prodrugs to toxic substances. Because of their inherent chemoresistance, they exert potent bystander and antitumor effect. Here we show that the human adipose tissue-derived MSC expressing fusion yeast cytosine deaminase::uracil phosphoribosyltransferase (CD-MSC) in combination with 5-fluorocytosine (5FC) mediated a long-term tumor-free survival in the 83.3% of tumor-bearing animals. CD-MSC/5FC treatment induced cytotoxicity against model human melanoma cells EGFP-A375. Only 4% of the therapeutic CD-MSC cells eliminated >98.5% of the tumor cells in vitro. Long-term tumor-free survival was confirmed in 15 out of the 18 animals. However, repeatedly used CD-MSC/5FC therapeutic regimen generated more aggressive and metastatic variant of the melanoma cells EGFP-A375/Rel3. These cells derived from the refractory xenotransplants exhibited increased resistance to the CD-MSC/5FC treatment, altered cell adhesion, migration, tumorigenic and metastatic properties. However, long-term curative effect was achieved by the augmentation of the CD-MSC/5FC regimen along with the inhibition of c-Met/hepatocyte growth factor signaling axis in this aggressive melanoma derivative. In summary, the CD-MSC/5FC regimen can be regarded as a very effective antitumor approach to achieve long-term tumor-free survival as demonstrated on a mouse model of aggressive human melanoma xenografts.

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Mesenchymal stem/stromal cells (MSC) possess a set of several fairly unique properties which make them ideally suitable both for cellular therapies and regenerative medicine. These include: relative ease of isolation, the ability to differentiate along mesenchymal and non-mesenchymal lineages in vitro and the ability to be extensively expanded in culture without a loss of differentiative capacity. MSC are not only hypoimmunogenic, but they mediate immunosuppression upon transplantation, and possess pronounced anti-inflammatory properties. They are able to home to damaged tissues, tumors, and metastases following systemic administration. The ability of homing holds big promise for tumor-targeted delivery of therapeutic agents. Viruses are naturally evolved vehicles efficiently transferring their genes into host cells. This ability made them suitable for engineering vector systems for the delivery of genes of interest. MSC can be retrovirally transduced with genes encoding prodrug-converting genes (suicide genes), which are not toxic per se, but catalyze the formation of highly toxic metabolites following the application of a nontoxic prodrug. The homing ability of MSC holds advantages compared to virus vehicles which display many shortcomings in effective delivery of the therapeutic agents. Gene therapies mediated by viruses are limited by their restricted ability to track cancer cells infiltrating into the surrounding tissue, and by their low migratory capacity towards tumor. Thus combination of cellular therapy and gene delivery is an attractive option - it protects the vector from immune surveillance, and supports targeted delivery of a therapeutic gene/protein to the tumor site.

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Recent research suggests that multinodular recurrent pleomorphic adenoma (PA) might result from cell migration through lymphatics. Lymphangiogenesis in malignancies is mediated by vascular endothelial growth factors C and D (VEGF-C/D). We studied the expression of VEGF-C/D in PA by immunohistochemistry as well as lymphatic vessel density (LVD). In 6 non-recurrent, 4 primary-to-recur, and 10 recurrent PAs, VEGF-C/D expression was assessed by immunohistochemistry. Staining was scored in terms of staining intensity (0 = absent to 3 = strong), and the percentage of positive tumor cells (scored as 0 (0-19 %), 1 (20-39 %), 2 (40-50 %), and 3 (60-100 %)) and a sum score were calculated. Intra- and peritumoral LVD was assessed by counting of LV after immunostaining, using the D2-40 antibody. All but one sample were VEGF-C negative. The differences in VEGF-D expression between non-recurrent, primary-to-recur, and recurrent PAs were not significant (p>0.05). VEGF-D expression did not correlate with peritumoral LVD (p>0.05). Our study revealed a significant difference between intra- and peritumoral LVD values when comparing individual and all sample groups (p=0.01). The lack of VEGF-C expression and of significant differences in VEGF-D expression and peritumoral LVD between patients with non-recurrent, primary-to-recur, and recurrent PAs does not support the lymphangiogenic local spread hypothesis

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UNLABELLED: Solid tumors are generally composed of two major components: heterogeneous malignant cells and non-malignant stromal part. The latter comprises several types of non-malignant cells of mesenchymal, endothelial and immune origin and together with the extracellular matrix significantly affects the biological properties of the tumor. This minireview is focused on recent advances in the understanding the role of tumor stromal component and its particular cell types in the tumor behavior. It summarizes the impact of mesenchymal stromal cells and the ways of their potential contribution to the tumor biology. As their role in the tumor development and the effects on the tumor cells remain controversial, we review the recent experimental evidence regarding the crucial molecular factors which determine their role in the tumors. KEYWORDS: tumor microenvironment, human mesenchymal stromal cells, paracrine interaction, malignant cells.

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AIM OF THE STUDY: To determine the prevalence of Chlamydia trachomatis infection in patients treated for infertility. STUDY TYPE: A retrospective analysis. SETTING: Fertimed, infertility treatment center, Olomouc. METHOD: At Fertimed, we used DNA detection of Chlamydia trachomatis by the PCR method of the company GeneProof to examine, between 2009-2011, 785 women undergoing one of the infertility treatment methods and their 113 partners. In the second group, we examined 121 oocyte donors and 30 men before sperm donation. We appraised the frequency of Chlamydia trachomatis detection in the specific groups and the clinical impact of the infection on the female reproductive organs. RESULTS: In the group of women treated for infertility, we detected 20 (2.5%) women with an active infection. After treatment, 9 of them underwent an examination of Fallopian tube patency using the UTHL (ultrasonographically guided transvaginal hydrolaparoscopy) method. In 7 cases, we indicated a bilateral salpingectomy due to a sactosalpinx and in one case severe pelvic adhesions were found (88.9%), and in one patient, the result was normal. In the control group of 43 PCR-negative women who were examined for Fallopian tube patency, 9.3% rate of tubal pathology was found (p<0.001). In the oocyte donor group, we detected the presence of Chlamydia trachomatis in 12 (9.9%) women, and in the sperm donor group, in 7.6% men. Treatment with 500 mg of Sumamed (azithromycin), given in 3 doses, was successful in all of the positive patients. CONCLUSION: We found that Chlamydia trachomatis detection was lower in the women treated for infertility than in the female donor group. Women with a confirmed infection had a high prevalence of inflammatory changes in the Fallopian tubes compared with women devoid of a confirmed infection. The treatment with azithromycin is effective.

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Human adipose tissue was shown to be a very attractive source of mesenchymal stromal cells that have a wide scale of potential applications in reconstructive plastic surgery and regenerative medicine. However, these cells were described to have profound effects on biological behaviour of tumour cells. The aim of this study was to analyze the influence of adipose tissue-derived human mesenchymal stromal cells (AT-MSC) on the proliferation of breast cancer cells. We have tested proliferation of three different human breast cancer cell lines under the influence of AT-MSC derived soluble factors as well as in the direct cocultures. These data were supplemented with the expression analysis of cytokines and their cognate receptors on the target cells. We have observed stimulation of proliferation in breast cancer cells MDA-MB-361, T47D and EGFP-MCF7. AT-MSC were found to secrete wide scale of cytokines, chemokines and growth factors, thus we concluded that this pro-proliferative effect was a result of their synergistic action. These data bring out a need to evaluate whether primary breast tumour derived human cells would respond to these type of stimuli in a similar manner in order to exclude any potential clinical risk related to the application of human mesenchymal stromal cells under the context of patient with history of breast cancer malignancy.

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Antibody (rituximab) dependent cellular cytotoxicity is a key mechanism in killing CD20+ lymphoma cells. FcγRIIIA-158 V/F gene polymorphism results in expression of 3 variants of the FcγRIIIA receptor (FcγRIIIA) on cytotoxic lymphocytes with different receptor affinity. We studied 102 patients with newly diagnosed FL to assess whether the FcγRIIIA genotype influences outcome in patients treated with risk-adapted immunochemotherapy. The median age was 52 years (31-84); 90% of the patients had advanced (III/IV) clinical stages. The Follicular Lymphoma International Prognostic Index (FLIPI) scores were as follows: low 18.9%, intermediate 33.7% and high 47.4%. The front-line treatment was stratified according to the commonly used risk factors (FLIPI, beta-2-microglobuline and serum-Tyrosine-Kinase levels, bulky disease) into 3 treatment groups: (1) patients with FLIPI 0-1 treated with (R)-CHOP (51%), (2) patients under 60 (65) years of age with intermediate-risk disease (FLIPI 2) indicated for an intensive protocol (ProMACE-CytaBOM or sequential chemotherapy) (21%), and (3) patients under 60 (65) years with high-risk disease (FLIPI ≥3) treated with intensive chemotherapy plus autologous stem cell transplantation (28%). Rituximab was added to front-line chemotherapy in 59% of the patients. Generally, complete remission (CR) or unconfirmed CR was achieved in 85% of the patients, 11% had partial remission and 4% stable disease. Molecular CR (CRm) was achieved in 67.4% of 86 evaluable patients. Overall survival (OS) at 5 years reached 84% (95% CI 0.74-0.93); event-free survival (EFS) at 5 years was 58% (95% CI 0.45-0.71). The frequencies of FcγRIIIA-158 gene polymorphisms V/V, V/F and F/F were 8%, 50% and 42%, respectively. The FLIPI score distribution was not different in F/F patients as compared to V/F+V/V carriers (chi-square, P=0.7). The treatment modalities (treatment arm or rituximab administration) had the same distribution in V/V+V/F vs F/F patients (chi-square, P=0.16 and P=0.62, respectively). The CRm rates were similar in both subgroups of V/V+V/F vs F/F patients (chi-square, P=0.92). Survival curves for OS and EFS were not significantly different when comparing the subgroups of V/V+V/F vs F/F patients (P=0.28 and P=0.57, respectively). We found no difference in the quality of treatment response or survival after front-line immunochemotherapy between FcγRIIIA subgroups. FcγRIIIA polymorphism have no influence on the outcome of patients treated with risk-adapted chemotherapy with or without rituximab.

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Human adipose tissue-derived mesenchymal (stromal) stem cells (AT-MSCs) and genetically modified to express cytosine deaminase:uracil phosphoribosyltransferase (CDy-AT-MSCs) were treated with hydrogen peroxide in order to induce DNA damage and subsequently evaluate their genetic stability by single cell gel electrophoresis. Both cells types (parental and transgene modified) did not differ in the sensitivity to DNA breaks induction. Potential tumorigenicity of AT-MSCs and CDy-AT-MSCs was tested by subcutaneous inoculation of cell suspension into flank of immunocompromised mice. Dose of 15x10(6) cells was not found to be tumorigenic in given experimental setup. AT-MSCs, CDy-AT-MSCs and MSCs isolated from human lipoma were treated with chemical carcinogen 4-nitroquinoline-1-oxide (4NQO) in attempts to transform them. Surviving cells after genotoxic stress were not transformed but underwent replicative senescence. Irreparable DNA damage caused triggered adipogenic terminal differentiation, rather than apoptosis induction in all kinds of cells tested.

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PURPOSE: The microenvironment established by stromal cells may or may not influence phenotypic aspects of epithelial cells and may be relevant for tumor and stem cell biology. We address this issue for keratinocytes using tumor-derived stromal cells in a co-culture system. MATERIALS AND METHODS: We isolated stromal cells from human squamous cell carcinoma tissue and studied their effect on phenotypic characteristics of normal human interfollicular keratinocytes in vitro. RESULTS: Stromal fibroblasts significantly influence immuno- and lectin cytochemical properties of co-cultured normal keratinocytes. Expression of keratins 8 and 19, the nucleolar protein nucleostemin, parameters related to adhesion/growth-regulatory galectins and the epithelial-mesenchymal transition were altered. This biological activity of tumor-derived stromal cells, which did not require cell contact, appeared to be stable, because it was maintained during passaging of keratinocytes in the absence of cancer cells. CONCLUSIONS: Tumor-derived stromal fibroblasts acquire distinct properties to shape a microenvironment conducive to altering the phenotypic characteristics of normal epithelial cells in vitro.

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