Previous research on the relationship between spatial memory and adult hippocampal neurogenesis has been controversial. In the present study, neurogenesis was compared between two natural populations of the same species that differ in their reliance on spatial memory to cache and retrieve stored food. Western red squirrels store food in a single site whereas eastern red squirrels store food in multiple sites. Neurogenesis was assessed using endogenous markers of the number of proliferating cells (Ki-67) and the number of immature neurons (DCX), and neuronal recruitment was determined by measuring the area of the dentate gyrus of the hippocampus. The number of proliferating cells, immature neurons and neuronal recruitment were enhanced in the eastern compared to the western red squirrels, reflecting the food storing strategies used by the squirrels. This suggests that there is a positive correlation between adult hippocampal neurogenesis and spatial learning and memory.

Previous research on the relationship between spatial memory and adult hippocampal neurogenesis has been controversial. In the present study, neurogenesis was compared between two natural populations of the same species that differ in their reliance on spatial memory to cache and retrieve stored food. Western red squirrels store food in a single site whereas eastern red squirrels store food in multiple sites. Neurogenesis was assessed using endogenous markers of the number of proliferating cells (Ki-67) and the number of immature neurons (DCX), and neuronal recruitment was determined by measuring the area of the dentate gyrus of the hippocampus. The number of proliferating cells, immature neurons and neuronal recruitment were enhanced in the eastern compared to the western red squirrels, reflecting the food storing strategies used by the squirrels. This suggests that there is a positive correlation between adult hippocampal neurogenesis and spatial learning and memory.

Deep brain stimulation (DBS) is currently being investigated as a therapy for treatment-resistant depression, with promising results. However, it is not clear whether or not DBS works via the same mechanisms as those induced by antidepressant medications. Processes currently implicated in antidepressant effects include neuroplastic changes and promotion of neurogenesis. We investigated the effects of chronic treatment with three different classes of antidepressants and DBS on markers of neuroplasticity (brain-derived neurotrophic factor, (BDNF), and phosphorylated cyclic-AMP regulatory element binding protein, (pCREB)) and neurogenesis (Ki-67, bromodeoxyuridine (BrdU) and doublecortin) in the rat hippocampus. No clear treatment effects were seen on BDNF, pCREB and Ki-67 levels. However all treatments caused increased levels of BrdU (range: 46%-96%) and doublecortin (8%-61%), although these effects were statistically significant only for DBS and amitriptyline, respectively. This overall pattern of results may suggest that diverse antidepressant treatments could possibly share common mechanisms involving cell survival and neuronal differentiation. Potentiated effects of DBS on cell survival may underlie its efficacy in treatment-resistant depression.

Deep brain stimulation (DBS) is currently being investigated as a therapy for treatment-resistant depression, with promising results. However, it is not clear whether or not DBS works via the same mechanisms as those induced by antidepressant medications. Processes currently implicated in antidepressant effects include neuroplastic changes and promotion of neurogenesis. We investigated the effects of chronic treatment with three different classes of antidepressants and DBS on markers of neuroplasticity (brain-derived neurotrophic factor, (BDNF), and phosphorylated cyclic-AMP regulatory element binding protein, (pCREB)) and neurogenesis (Ki-67, bromodeoxyuridine (BrdU) and doublecortin) in the rat hippocampus. No clear treatment effects were seen on BDNF, pCREB and Ki-67 levels. However all treatments caused increased levels of BrdU (range: 46%-96%) and doublecortin (8%-61%), although these effects were statistically significant only for DBS and amitriptyline, respectively. This overall pattern of results may suggest that diverse antidepressant treatments could possibly share common mechanisms involving cell survival and neuronal differentiation. Potentiated effects of DBS on cell survival may underlie its efficacy in treatment-resistant depression.

Objetivos do Estudo: O aumento do crescimento de melanoma foi avaliado em camundongos expostos a hipóxia intermitente. As proteínas que caracterizam a agressividade do tumor ainda não foram investigadas. O estudo teve como objetivo verificar se a hipóxia intermitente simulada pela apneia do sono afeta marcadores de melanoma na progressão tumoral. Desenho: Estudo prospectivo controlado em animais. Senário: Hospital Universitário. Participantes: Doze camundongos C57BL/6. Intervenções: Camundongos foram expostos a hipóxia intermitente ou simulada. Durante 8 horas por dia, o grupo hipóxia foi submetido a um total de 480 ciclos de 30 segundos de hipóxia progressiva SpO2 nadir de 8 ± 1%, seguidos por 30 segundos de normóxia. Um milhão de células de melanoma B16F10 foi injetado por via subcutânea. No dia 14, após a eutanásia, os tumores foram removidos, fixados e corados. Médias e resultados: coloração imunohistoquímica de Ki-67, PCNA, S100-B, HMB-45, Melan-A, TGF, Caspase-1 e HIF-1α foi quantificada por dois observadores que utilizaram captura digital e processamento em três lâminas de cada animal para cada marcador. O tamanho e o peso dos tumores foram semelhantes nas experiências de hipóxia e simulada. A percentagem da mediana [25-75 quartis] de área positiva corada para Ki-67 foi de 23% [15-28] no grupo hipóxia e 0,3% [0,2-1,1] no grupo controle (P = 0,02); para PCNA, as percentagens foram 31% [25-38] e 7% [5-18], respectivamente (P = 0,009). As diferenças entre os grupos para os marcadores restantes não foram significativas. Conclusões: Os marcadores da transcrição do RNA ribossomal e da síntese de DNA são mais expressos em tumores de camundongos expostos a hipóxia intermitente do que em controles, indicando que a apneia do sono pode levar a uma maior agressividade do tumor. / Study Objectives: Increased melanoma growth has been reported in mice exposed to intermittent hypoxia. Proteins that characterize tumor aggressiveness have not been investigated. The study aims to verify whether intermittent hypoxia mimicking sleep apnea affects markers of melanoma tumor progression. Design: Prospective controlled animal study. Settings: University hospital. Participants: Twelve C57bl/6 mice. Interventions: Mice were exposed to intermittent or sham hypoxia. During 8 hours per day, the hypoxia group was submitted to a total of 480 cycles of 30 seconds of progressive hypoxia to a nadir FIO2 of 8±1%, followed by 30 seconds of normoxia. One million B16F10 melanoma cells were injected subcutaneously. On the 14th day, after euthanasia, tumors were removed, fixed and stained. Measurements and Results: Immunohistochemistry staining for Ki-67, PCNA, S100-B, HMB-45, Melan-A, TGFβ, Caspase-1 and HIF-1α was quantified by two observers using digital capture and processing in three slides from each animal for each marker. The size and weight of the tumors were similar in hypoxia and simulated experiments. Median [25-75 quartiles] percentage of positive area stained for Ki-67 was 23% [15-28] in the hypoxia group and 0.3% [0.2-1.1] the control group (P=0.02); for PCNA, the percentages were 31% [25-38] e 7% [5-18], respectively (P=0.009). The differences between the groups for the remaining markers were not significant. Conclusions: Markers of ribosomal RNA transcription and of DNA synthesis are more expressed in tumors of mice exposed to intermittent hypoxia than of controls, indicating that sleep apnea can lead to greater tumor aggressiveness.

Objetivos do Estudo: O aumento do crescimento de melanoma foi avaliado em camundongos expostos a hipóxia intermitente. As proteínas que caracterizam a agressividade do tumor ainda não foram investigadas. O estudo teve como objetivo verificar se a hipóxia intermitente simulada pela apneia do sono afeta marcadores de melanoma na progressão tumoral. Desenho: Estudo prospectivo controlado em animais. Senário: Hospital Universitário. Participantes: Doze camundongos C57BL/6. Intervenções: Camundongos foram expostos a hipóxia intermitente ou simulada. Durante 8 horas por dia, o grupo hipóxia foi submetido a um total de 480 ciclos de 30 segundos de hipóxia progressiva SpO2 nadir de 8 ± 1%, seguidos por 30 segundos de normóxia. Um milhão de células de melanoma B16F10 foi injetado por via subcutânea. No dia 14, após a eutanásia, os tumores foram removidos, fixados e corados. Médias e resultados: coloração imunohistoquímica de Ki-67, PCNA, S100-B, HMB-45, Melan-A, TGF, Caspase-1 e HIF-1α foi quantificada por dois observadores que utilizaram captura digital e processamento em três lâminas de cada animal para cada marcador. O tamanho e o peso dos tumores foram semelhantes nas experiências de hipóxia e simulada. A percentagem da mediana [25-75 quartis] de área positiva corada para Ki-67 foi de 23% [15-28] no grupo hipóxia e 0,3% [0,2-1,1] no grupo controle (P = 0,02); para PCNA, as percentagens foram 31% [25-38] e 7% [5-18], respectivamente (P = 0,009). As diferenças entre os grupos para os marcadores restantes não foram significativas. Conclusões: Os marcadores da transcrição do RNA ribossomal e da síntese de DNA são mais expressos em tumores de camundongos expostos a hipóxia intermitente do que em controles, indicando que a apneia do sono pode levar a uma maior agressividade do tumor. / Study Objectives: Increased melanoma growth has been reported in mice exposed to intermittent hypoxia. Proteins that characterize tumor aggressiveness have not been investigated. The study aims to verify whether intermittent hypoxia mimicking sleep apnea affects markers of melanoma tumor progression. Design: Prospective controlled animal study. Settings: University hospital. Participants: Twelve C57bl/6 mice. Interventions: Mice were exposed to intermittent or sham hypoxia. During 8 hours per day, the hypoxia group was submitted to a total of 480 cycles of 30 seconds of progressive hypoxia to a nadir FIO2 of 8±1%, followed by 30 seconds of normoxia. One million B16F10 melanoma cells were injected subcutaneously. On the 14th day, after euthanasia, tumors were removed, fixed and stained. Measurements and Results: Immunohistochemistry staining for Ki-67, PCNA, S100-B, HMB-45, Melan-A, TGFβ, Caspase-1 and HIF-1α was quantified by two observers using digital capture and processing in three slides from each animal for each marker. The size and weight of the tumors were similar in hypoxia and simulated experiments. Median [25-75 quartiles] percentage of positive area stained for Ki-67 was 23% [15-28] in the hypoxia group and 0.3% [0.2-1.1] the control group (P=0.02); for PCNA, the percentages were 31% [25-38] e 7% [5-18], respectively (P=0.009). The differences between the groups for the remaining markers were not significant. Conclusions: Markers of ribosomal RNA transcription and of DNA synthesis are more expressed in tumors of mice exposed to intermittent hypoxia than of controls, indicating that sleep apnea can lead to greater tumor aggressiveness.

A subset of eukaryotic heterochromatin is located around the nucleoli, and this localization is correlated with gene silencing. Although there is some evidence for trans-acting factors organizing genomic loci around the nucleolus, the characterization of proteins and /or RNAs involved in perinculeolar heterochromatin localization and maintenance is incomplete. Notably, the mammalian female inactive X chromosome, a well-studied model of facultative heterochromatin, frequently resides in the perinucleolar regions during mid to late S phase. The disruption of the Xi–nucleolus association results in the erosion of heterochromatin compartment and silencing, which renders it a good model to investigate the mechanism and biological relevance of heterochromatin organization around the nucleolus. This dissertation will present evidence showing that Ki-67 regulates inactive X (Xi) chromosome association with nucleoli, maintains Xi heterochromatic structures, and regulates cell cycle progression, in cell-type-specific manner dependent on checkpoint proficiency. Ki-67 protein plays roles in heterochromatin organization during interphase. Upon Ki-67 depletion, a subset of Xi in human female hTERT-RPE1 moved away from nucleolus and displayed several features of compromised heterochromatin maintenance. These chromatin alterations were limited to Xi chromosomes localized away from the nuclear lamina and were not observed in virally transformed 293T cells upon Ki-67 depletion. Furthermore, I demonstrated that the different Xi heterochromatin alteration responses result from cell-type-specific reduced proportion of cells in S phase upon Ki-67 depletion. In human hTERT-RPE1, WI-38, IMR90, hTERT-BJ cell lines, depletion of Ki-67 slowed entry into S phase and coordinately downregulated genes related to DNA replication. These cell lines are able to induce p21 expression upon Ki-67 depletion. On the contrary, alteration of transcription and cell cycle progression were not observed in tumor-derived HeLa, U2OS and 293T cell lines. These cell lines do not induce p21 expression either. I additionally examined the Ki-67 function in mouse cell cultures. Depletion of Ki-67 neither redistributes inactive X chromosome nor regulates S phase progression in primary female mouse embryonic cells.

Base teórica: doenças linfoproliferativas crônicas de linhagem B (DLPC-B) são neoplasias clonais que afetam linfócitos B maduros. A tirosina quinase de Bruton (do inglês Bruton’s tyrosine kinase, BTK) é uma proteína essencial para o desenvolvimento, diferenciação e sinalização nos linfócitos B. Ki-67 é uma proteína nuclear associada à proliferação celular. A avaliação de proteínas envolvidas nas vias de sinalização oncogênicas pode levar ao aprimoramento do diagnóstico, tratamento e definição de prognóstico das DLPC-B. Objetivo: avaliar a expressão de BTK e Ki-67 em linfócitos de portadores de DLPC-B. Métodos: para avaliação de BTK foi realizado um estudo transversal; foi avaliada a expressão de BTK em amostras de pacientes saudáveis e de pacientes com diagnóstico de DLPC-B. Para avaliação de Ki-67 foi realizado um estudo transversal. As amostras foram marcadas com CD45 FITC e CD19 APC para identificação dos linfócitos B. Após a lise das hemácias, foi realizada marcação citoplasmática de BTK PE e/ou Ki-67 PerCP-Cy5.5. O percentual de expressão e a intensidade de fluorescência média (IFM) dos marcadores avaliados foram determinados nos linfócitos B. A análise estatística foi realizada com testes de correlação de Pearson e Spearman entre BTK ou Ki-67 e as demais variáveis clínicas e laboratoriais, e ANOVA seguido por teste post hoc de Bonferroni para comparações entre grupos. Foi considerado resultado significante quando P < 0,05. Resultados: não foram observadas diferenças na expressão de BTK e não houve associação entre a expressão de BTK e as variáveis clínicas avaliadas. A expressão de Ki-67 foi maior nos grupos linfoma do manto, linfoma de Burkitt e linfoma difuso de grandes células B em relação aos demais; após análise multivariada, a IFM de Ki-67 foi associada à IFM de CD38. Conclusão: no presente trabalho, a expressão de BTK em DLPC-B foi similar a de linfócitos B normais e a expressão de Ki-67 foi maior nas DLPC-B com curso clínico mais agressivo. / Background: mature B-cell neoplasms (MBCN) are clonal neoplasms that affect mature B-cell lymphocytes. Bruton’s tyrosine kinase (BTK) is an essential protein for the development, differentiation and signaling in B-cell lymphocytes. Ki-67 is a nuclear protein associated to cellular proliferation. Evaluation of proteins involved in oncogenic signaling pathways can lead to improvement in the diagnosis, treatment and prognosis definition in MBCN. Objective: to evaluate the expression of BTK and Ki-67 in lymphocytes of MBCN patients using flow cytometry. Methods: a cross-sectional study was conducted for BTK assessment; BTK expression was assessed on healthy patients samples and MBCN samples. For evaluation of Ki-67 a cross-sectional study was conducted. Samples were stained with CD45 FITC and CD19 APC for identification of B-cell lymphocytes. After lysis of red blood cells, cytoplasmic staining of BTK PE and/or Ki-67 PerCP-Cy5.5 was performed. Percentage of expression and mean fluorescence intensity (MFI) of the markers were determined in B-cell lymphocytes. Statistical analysis was performed with Pearson and Spearman correlation tests between BTK and Ki-67 and the other clinical and laboratory variables, and ANOVA followed by post-hoc Bonferroni test for comparisons between groups. Results were considered significant when P < 0.05. Results: no differences in BTK expression were identified and there was no association between BTK expression and clinical variables evaluated. Ki-67 expression was higher in mantle cell lymphoma, Burkitt lymphoma and diffuse large B-cell lymphoma cases; after multivariate analysis, MFI of Ki-67 was associated with MFI of CD38. Conclusions: in this study, BTK expression in B-cell neoplasms was similar to that of normal B-cell lymphocytes and Ki-67 expression was higher in MBCN with more aggressive clinical courses.

<p>The natural history of localized prostate cancer is not fully understood. In most patients the tumor will never progress to a lethal disease, while a subset of patients will ultimately die of the disease. Efficient tools to separate indolent from lethal disease is currently lacking which means that many patients will be offered treatment without any benefit, but still be at risk of experiencing treatment related side effects.</p><p>The aims of these studies were to get more insight into the natural history of untreated localized prostate cancer, to assess the prognostic value of established clinical parameters such as Gleason score, nuclear grade and tumor volume and, moreover, some new prognostic markers Ki-67, AMACR and MUC-1. We also aimed to study time trends in the detection of incidental tumors in Sweden.</p><p>Patients with localized disease (n=223) and no initial treatment were followed for 21 years. Most patients had a favorable outcome. However, a subset of patients developed lethal disease even beyond 15 years of follow-up and these patients define the group that may benefit most from treatment with curative intent. Patients with poorly differentiated tumors experienced a 9 time higher risk of dying in prostate cancer.</p><p>The studies on prognostic markers are based on a cohort of patients (n=253) with incidental prostate cancer detected by transurethral resection for presumed benign hyperplasia. All patients were left without initial treatment. Gleason grade, nuclear grade and tumor volume turned all out to be independent prognostic factors. MUC-1, AMACR and Ki-67 also carried prognostic information. However, after adjustment for Gleason grade, nuclear grade and tumor volume only MUC-1 and AMACR remained as statistically significant prognostic factors. When tested for sensitivity and specificity they all failed and, consequently, they seem to be of less value in daily practice for cancelling an individual patient regarding the choice of treatment.</p><p>Time trends in incidental prostate tumors in Sweden were analyzed in a cohort of patients with prostate tumors detected by transurethral resection (TUR-P). Through linkage of the national registration number (NRN) with several registers, e.g. the Swedish Cancer Registry, the National Inpatient registry and the Cause of Death Registry we identified, during the period 1970 through 2003, in total 23288 patients with incidental prostate cancer, who constituted the study group. As comparison group we choose all patients diagnosed with prostate cancer between 1970-2003 excluding those with incidental cancer, in total 112204 patients. Our result confirms earlier findings that there has been a dramatic change over time in incidence of incidental prostate cancers in Sweden, which parallels the introduction of prostate specific antigen. We also found that the cumulative incidence of prostate cancer death is high in the incidental group, opposing earlier findings that incidental tumours are a non-lethal disease.</p> / issn 1642-4063

<p>The incidence of breast cancer is rising steadily in Sweden and the proportion of carcinoma in situ (CIS) has increased appreciably, most likely due to mammography screening. The aim of this study was twofold: (1) to examine risk factors for subsequent invasive breast carcinoma and breast cancer death after primary ductal carcinoma in situ (DCIS) and (2) to study the biology in the progress between in situ and invasive carcinoma.</p><p> In a cohort-study based on 3,398 women with a primary CIS reported to the Swedish Cancer Registry (SCR) 1980-1992, women diagnosed in 1989-1992 ran a relative risk of 0.1 (CI 95%, 0.0-0.9) from dying of breast cancer as compared with women diagnosed in 1980-1982. Women in counties with mammography screening ran a relative risk of 0.2 (CI 95%, 0.0-2.1) for breast cancer death in comparison with women in non-screening counties.</p><p> In a case-control study derived from all 4,661 women with primary CIS reported to the SCR 1960-1992, we investigated risk factors for subsequent invasive breast carcinoma (n=118) and breast cancer death (n=39). Large size and multifocality were found to increase the risk for breast cancer death. Postoperative radiotherapy and mastectomy lowered the risk for ipsilateral invasive cancer.</p><p> The standardised incidence rates (SIR) for invasive breast cancer were estimated in the cohort from 1980-1992. The SIR after primary DCIS and primary lobular carcinoma in situ (LCIS) was 4.5 (CI 95%, 3.7-5.5) and 4.0 (CI 95%, 2.1-7.5), respectively.</p><p> New histopathological classification systems for DCIS were evaluated in 195 women consecutively diagnosed with primary DCIS between 1986-1994. One group with highly differentiated lesions was defined with the EORTC classification system and had an excellent prognosis.</p><p> Histopathological grade and expression of p53, c-erbB-2, Ki 67, hormone receptors, Bcl-2 and angiogenesis were compared in 626 women with either a pure DCIS, a small invasive carcinoma or a lesion with both an invasive and in situ component. When grade was taken into account, no change in tumour markers could be detected that signalled the progression from an in situ stage to invasiveness. All tumour markers correlated to grade and their distribution was very similar in the two components of mixed lesions.</p>