CNS-PNETs are rare, aggressive, paediatric embryonal brain tumours that are poorly studied. We recently identified an aggressive sub-group of CNS-PNETs characterized by the amplification of the C19MC microRNA cluster, however, little is known regarding the features of other CNS-PNET tumours. This study was designed to define additional molecular sub-groups of CNS-PNET by interrogating a large cohort of CNS-PNETs. To elucidate the features of CNS-PNET, we examined transcriptional and copy number profiles from primary hemispheric CNS-PNETs. We then validated and examined the clinical significance of novel sub-group markers in 123 primary CNS-PNETs. This thesis demonstrates that CNS-PNET can be categorized into three molecular sub-groups that are distinguished by distinct primitive neural, oligo-neural and mesenchymal lineage gene expression signatures and also correlated with distinct clinical features. Data from my thesis has generated a substantial body of knowledge to fuel both biological and clinical investigations of childhood CNS-PNETs.

CNS-PNETs are rare, aggressive, paediatric embryonal brain tumours that are poorly studied. We recently identified an aggressive sub-group of CNS-PNETs characterized by the amplification of the C19MC microRNA cluster, however, little is known regarding the features of other CNS-PNET tumours. This study was designed to define additional molecular sub-groups of CNS-PNET by interrogating a large cohort of CNS-PNETs. To elucidate the features of CNS-PNET, we examined transcriptional and copy number profiles from primary hemispheric CNS-PNETs. We then validated and examined the clinical significance of novel sub-group markers in 123 primary CNS-PNETs. This thesis demonstrates that CNS-PNET can be categorized into three molecular sub-groups that are distinguished by distinct primitive neural, oligo-neural and mesenchymal lineage gene expression signatures and also correlated with distinct clinical features. Data from my thesis has generated a substantial body of knowledge to fuel both biological and clinical investigations of childhood CNS-PNETs.

Pleural solitary fibrous tumours (pSFTs) are uncommon soft tissue tumours of the pleura. that may recur and contribute to the patients’ demise. We analyzed a group of benign and malignant pSFTs for copy number alterations and for common mutations in oncogenes and tumour-suppressor genes. Malignant SFTs demonstrated more copy number alterations, especially 8q (c-myc) gain, 10q (include PTEN) loss, and 13q (Rb1) loss. Mutations were rare in this limited study.

Pleural solitary fibrous tumours (pSFTs) are uncommon soft tissue tumours of the pleura. that may recur and contribute to the patients’ demise. We analyzed a group of benign and malignant pSFTs for copy number alterations and for common mutations in oncogenes and tumour-suppressor genes. Malignant SFTs demonstrated more copy number alterations, especially 8q (c-myc) gain, 10q (include PTEN) loss, and 13q (Rb1) loss. Mutations were rare in this limited study.

Summary Public Health Ecology Operating conditions of Kaunas city firefighters and correlation with health disturbances Laimis Grigelevičius Supervisor Rita Raškevičienė, MD, PhD., Department of Environmental and Occupational Medicine. Faculty of Public Health, Kaunas University of Medicine. – Kaunas, 2005. – P. 61 Objective To analyse operating conditions of Kaunas city firefighters and correlation with health disorders Methods It was made cross-sectional (prevalence) study. Surveyed population was 223 firefighters: 7 females and 216 males. Respondents were 20-53 years old. Statistical data analysis was performed with the statistical package SPSS 11.0 for Windows and Microsoft Excel XP. The differences inside the sample were tested with χ2 – test. For risk estimation was counted odds ratio with 95 % confidence interval (C.I. = 0.95). Results It was estimated that firefighters whose working in noisy environment 10 times more often feeling nervous strain, 13 times more often having disorders of sleep. Respondents whose feeling nervous strain at work 5 times more often have sleep disorders. Respondents constantly lifting heavy weights 30 times more often feel stress at work, they have 3.5 times higher risk of sleep disorders and 6 times higher risk of injuries. After having injuries firefighters get 3.5 times higher risk of sleep disorders and 20 times higher risk of hearing damage. Heat caused health disorders (swelter, convulsions, spasm of muscles) risk gets higher 4.3... [to full text]

Cancer is a disease that is caused by mutations in somatic cells. Metastasis is the major cause of death from cancer and often complicates treatment. Malignant tumours secrete degradative enzymes such as cathepsin L which degrade the extracellular matrix to facilitate tumour invasion and metastasis. The immune system does not normally recognize and eradicate tumours because they arise from self tissues to which the immune system is tolerant. Self antigens are poorly immunogenic because they lack T cell help. In this study, a foreign glucosidase was conjugated to self rabbit cathepsin L using glutaraldehyde to specifically provide T helper cell epitopes. The conjugate was used to immunise two male rabbits. A second pair of rabbits (male and female), was primed with sheep cathepsin L (to induce T helper cell activation) and received rabbit cathepsin L boosters. A third pair of rabbits which served as a control was immunised with sheep cathepsin L. The two pairs of test rabbits made high avidity antibodies against rabbit cathepsin L, showing a similar response to control rabbits when antibodies were tested in an ELISA. Western blot analysis showed that these anti-cathepsin L autoantibodies were specific for rabbit cathepsin L. Rabbits which were immunised with the conjugate were · inoculated with sheep cathepsin L nine weeks after the final inoculation with the conjugate. Analysis of antibodies in an ELISA showed that antibody responses against rabbit cathepsin L were augmented in a manner that is characteristic of memory responses. Low titre antibodies against sheep cathepsin L were also produced. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

MUDr. SKALICKÝ, Tomáš Five year period of experimental and clinical experience with radiofrequency ablation of liver tumors is described. RFA considerably extends the survival of patients with non-resectable liver metastases. The method has minimal complications and both mortality and morbidity are low.

Lung cancer is the most common cause of cancer-related mortality worldwide with current treatments providing limited therapeutic benefit in most cases. TP53 (Trp53, p53) mutations occur in approximately 50% of lung adenocarcinoma cases and are associated with poor prognosis and so novel therapies that target these p53 mutant lung tumours are urgently needed. Despite the high frequency of p53 mutations in lung tumours, the impact these mutations have on response to therapy remains unclear in this cancer type. The aim of my project is to characterise the gain-of-function and dominant-negative effects of p53 mutations in lung tumours and to identify ways of therapeutically targeting these p53 mutant tumours based on dependencies and susceptibilities that our analysis uncovers. To characterise the gain-of-function and dominant-negative effects of p53 mutations I compared p53 mutant murine lung tumour cells that endogenously express either a contact (R270H, equivalent to R273H in humans) or conformational (R172H, equivalent to R175H in humans) p53 mutant protein and p53 null lung tumour cell lines; both in the presence and absence of wild-type p53. Interestingly, transcriptional and functional analysis uncovered metabolic gain-of-functions that are specific to the type of p53 mutation. Upregulation of mevalonate pathway expression was observed only in R270H lung tumours and consequently R172H and R270H lung tumours displayed distinct sensitivities to simvastatin, a mevalonate pathway inhibitor widely used in the clinic. Furthermore, the transcriptional signature underlying this sensitivity to simvastatin was also present in human lung tumours with contact p53 mutations, indicating that these findings may be clinically relevant. On the other hand, our analysis of the potential dominant-negative effects of the p53 mutants on wild-type p53 demonstrated that wild-type p53 was able to induce typical p53 target genes to a similar level in p53 null and mutant cells. Furthermore, wild-type p53 restoration resulted in comparable tumour suppressive responses in p53 mutant and null tumours and thus, p53-restoration therapy will likely be of benefit to patients with p53 mutations in lung cancer. Hence, I have demonstrated that lung tumours harbouring contact and conformational p53 mutations display common and distinct therapeutic susceptibilities.

This study was carried out to determine the phenotype of special dog mammary gland tumours that were grown in nude mice. 26 tumours were examined by the immunohistochemical ABC-Elite protocol. The tumour tissues were labelled with following anti-human antibodies: - AE1/AE3 (pankeratin antibody) labelled epithelial and myoepithelial cells - CD 31 labelled endothelial cells - desmin labelled cross-striated and smooth muscle cells - myosin labelled cross striated muscle cells - neurofilament (NF) labelled nerve cells - osteopontin labelled preosteoblasts, osteoblasts and osteocytes - p63 labelled nuclei of the myoepithelial cells - smooth muscle actin (SMA) labelled the cytoplasm of myoepithelial cells - type I collagen labelled the extracellular matrix in connective tissue and bone - type II collagen labelled the extracellular matrix in cartilage - vimentin labelled fibroblasts, fibrocytes, lipocytes, smooth muscle cells, endothelial cells, nerve cells, macrophages and myoepithelial cells The tumours were also submitted to a double immunolabelling study using p63 and SMA. The study could not give a final conclusion about the origin the tumours. There was still need for more research to answer that question. However, the immunohistochemical technique was analysed in detail, in order to obtain perfect labelings. Initially, all the antibodies were tested on normal dog tissue, to acquire the best working dilutions with the lowest background problems. In the tumours, good results were obtained with these dilutions for the antibodies p63, SMA, vimentin, desmin, NF, AE1/AE3 and CD 31. Except for type I collagen, type II collagen and osteopontin that gave too much unspecific labelling of the mouse connective tissue. Even, when using the Vector® M.O.M. blocking kit, the results were still very difficult to interpretate. The antigen retrieval methods were evaluated for all the antibodies. The antibodies p63, SMA, vimentin, desmin, AE1/AE3, myosin, neurofilament and CD 31 needed the antigen retrieval treatment. The antibodies type I collagen and type II collagen needed the treatment with the enzyme pepsin, while osteopontin did not need any pretreatment at all. The double immunolabelling with p63 and SMA gave excellent results. Different combinations were tried out with different substrates, namely Vector® Nova RED, Vector® DAB and Vector® SG. Vector® methyl green was used as counterstaining, but it interfered with the other substrates, and better results were obtained without this counterstaining.

Pancreatic ductal adenocarcinoma (PDAC) is characterised by an abundant desmoplastic reaction driven by pancreatic stellate cells (PSCs). There is accumulating evidence that PSCs influence the malignant phenotype of PDAC. The aim of this study was to analyse the tumour response to radiation treatment in the presence of PSCs and to investigate the cytokine network in the coculture of PSCs and pancreatic cancer cells (PCCs). PSCs were used in coculture with different PCC lines. Clonogenic survival assays of several PCC lines cocultured with PSCs showed decreased radiosensitivity. This effect was abrogated by inhibition of the β1-integrin/FAK signalling pathway. Furthermore, tumour regrowth experiments after irradiation showed that coinjected PSCs were radioprotective for PCCs after single-dose and fractionated irradiation in xenografts. In addition, we examined the expression of 50 proteins in the supernatants of PCCs and PSCs in mono- and coculture conditions. The detected cytokine expression profile of PSCs included many proinflammatory factors. Also, we identified IP-10 as the chemokine with the highest differential upregulation in PSCs by paracrine stimuli from five different PCC lines. Human PDAC with a high stroma component had elevated IP-10 mRNA expression. IP-10 did not stimulate tumour cell growth and migration in our conditions even though several PCCs expressed its cognate receptor CXCR3. Nevertheless, we discovered that in human PDAC samples IP-10 and CXCR3 mRNA levels correlated with the presence of CD3ε, CD4, FoxP3, CTLA4 and CD39 used as surrogate markers for T regulatory cells (Tregs), known to exert an immunosuppressive effect. In conclusion, these data demonstrate that PSCs enhance survival of PCCs to radiation by activating β1-integrin/FAK signalling. Furthermore, the interaction between the tumour stroma in pancreatic cancer may support an immunosuppression by chemoattraction of Tregs following upregulation of IP-10. Further characterisation of the paracrine signalling between PCCs, PSCs and immune cells will improve the understanding of pancreatic cancer biology and could lead to the identification of new targets for multimodal therapy.