Aim: The aim of this study was to investigate the expression of Sox1 and Sox2 transcriptional factors in the subgranular zone (SGZ) of the hippocampus in 8 weeks old 5xFAD mice. Introduction: Transgenic 5xFAD mice represent a model of Alzheimer s disease (AD) characterized by an early deposition of amyloid plaques which disrupt the process of adult neurogenesis in the hippocampus. Certain transcriptional factors such as SoxB1 transcriptional factors are involved in the process of adult neurogenesis, but their roles in neurodegenerative disorders are not fully understood. Material and Methods: Transgenic mice of both genders and their respective non-transgenic controls (n=6 per group) were used in the study. Proliferating cells and immature neurons were detected by their immunohistochemical expression of Ki67 and doublecortin, while neuronal stem/precursor cells were identified by the expression of Sox1 and Sox2 proteins. Immunohistochemistry and counting were performed on hippocampal paraffin sections. Results: Immunohistochemical analysis showed that 5xFAD mice in the SGZ of the hippocampus have significantly lower numbers of Sox1 immunoreactive cells, while Sox2 immunoreactive cells were lower only in female 5xFAD mice. Furthermore, we have detected a decrease in the number of newly formed neurons in male transgenic mice, while the number of proliferating cells was unchanged when compared to non-transgenic controls. Conclusion: The results of our study show that early changes in the neurogenesis in 5xFAD model occur despite the preserved proliferative potential in the SGZ. Our results clearly indicate the importance of SoxB1 transcriptional factors in the early phases of AD.

Aim: To investigate co-expression of ATRX and HIF-1α in kidney neoplasm in relation to its origin. Introduction: A heterogenous group of kidney tumors is believed to arise from a variety of specialized cells along the nephron – proximal tubules [Clear cell Renal Cell carcinoma (ccRCC) and papillary RCC (pRCC)] and collecting tubules [chromophobe RCC (chRCC) and oncocytoma]. ATP-dependent helicase (ATRX) is a chromatin remodeling protein involved in gene regulation and aberrant DNA methylation during cancerogenesis. Activation of hypoxia inducible factor (HIF-1α) is an early event in most RCC following inactivation of the VHL tumor suppressor gene. Material and Methods: A total of 46 kidney tumors (n=33 ccRCC, n=1 mRCC, n=4 pRCC, n=5 chRCC and n=3 oncocytomas) was immunohistochemically analyzed for ATRX and HIF-1α expression. Results: Diffuse and focal positivity of ATRX expression was found in 51.5% of ccRCC, while 54.5% had HIF-1α positivity. Co-expression of ATRX/HIF-1α was not related to nuclear grade and stage of ccRCC. Metastatic ccRCC had strong expression of both markers. pRCC type II showed weak ATRX/HIF-1α expression, while pRCC type I was negative for both markers. Interestingly, all analyzed oncocytomas and chromophobe RCC were negative for ATRX/HIF-1α. Conclusion: Our results suggest that signaling pathways have different patterns of activation/suppression of ATRX/HIF-1α in oncocytomas and chRCC compared to other RCC types. Downregulation or loss of ATRX/HIF-1α coexpression in benign tumors should be further investigated in order to determinate mechanisms of ATRX/ HIF-1α signaling transport renal neoplasm with different origin.

Aim: To determine prognosic significance of RAS oncogene mutation detection in patients with metastatic colorectal carcinoma (mCRC). Introduction: CRC is still third most common cancer of both genders and second cause of death from malignancy in Western countries. In recent years, detecting RAS mutation in mCRC tumor tissue has became an imperative in selecting patients for monoclonal antibodies targeted therapy to Epidermal Growth Factor Receptor (EGFR). Nevertheless, there is no consensus regarding prognostic relevance of determining RAS status in patients with mCRC. Material and methods: Study included 116 patients with surgicaly resected CRC at Oncology Insitute of Vojvodina between January and December 2016. KRAS mutation detection was performed in formalin-fixed paraffin embeded tumor tissue samples processed by real-time chain polymerase reaction (real-time PCR) and applyng Cobas® KRAS Mutation Test and Cobas® 4800 System for detection of mutations in codons 12/13 and 61 of KRAS gene. Results: Average age in tested population was 65 years, with a male gender predominance (66.4%). Presence of KRAS mutation was found in 50.9% patients: 44.8% in codons 12/13, 4.3% in codon 61 and 1.7% in both codons 12/13 and 61. RAS mutated colorectal carcinomas (n=59) compared with RAS wildtype colorectal cancers, were significantly associated with male gender, moderately differentiated tumors, lymphovascular invasion and local nodal metastases. Conclusion: Our results show that, beside predictive, KRAS can also have prognostic significance regarding risk assesment for lymphovascular invasion and presence of local and distant metastases.

Aim: Evaluation of the usefulness of flow cytometry (FCM) serous effusion analysis in a diagnosis of pediatric Non-Hodgkin lymphomas (NHL). Introduction: Serous effusions are often the first, life-threatening manifestation of pediatric NHL. FCM immunophenotyping of effusions with cytological analysis could help in diagnosis of NHL, and thus enable fast initiating of cytoreductive therapy. Material and Methods: FCM analysis of serous effusions obtained from 17 children and adolescents hospitalized in Mother and Child Healthcare Institute of Serbia under clinical suspicion of NHL using the standardized panel of monoclonal antibodies: CD19, iCD79a, CD20, CD10, iIgM, kappa/lambda, iCD3, sCD3, CD7, CD2, CD5, CD4, CD8, CD1a. Cytological examination was performed on May-Grunwald-Giemsa stained slides. The results were correlated with histopathological findings of available tumor biopsies. Results: Precursor T-cell (T-III/T-IV) phenotype was confirmed in 5 samples. In 7/9 samples with mature B (B-IV) phenotype, FAB L3 cytomorphology indicated Burkitt lymphoma (BL), and in 2/8 suggested diffuse large B-cell lymphoma (DLBCL). Tumor biopsy was available in 7/14 patients and in all cases preliminary diagnosis was confirmed. In 3 patients with no malignant cells in effusions, FCM and cytomorphologicaly only reactive changes were observed, and diagnosis had to be made by tumor biopsy (BL 2 patients, DLBCL 1 patient). Out of 7 patients diagnosed only by FCM and cytological analysis, 6 achieved a remission of the illness. Conclusion: FCM detects NHL cells in malignant serous effusions fast and accurate. In combination with cytological analysis, FCM is sufficient for diagnosis in most cases, allowing rapid initiation of therapy.