The phosphatidylinositol-3-kinase (PI3K) and AKT (protein kinase B) signaling pathways play an important role in regulating cell cycle progression and cell survival. In previous studies, we demonstrated that AKT is activated in HTLV-1-transformed cells and that Tax activation of AKT is linked to p53 inhibition and cell survival. In the present study, we extend these observations to identify regulatory pathways affected by AKT in HTLV-1-transformed cells. We demonstrate that inhibition of AKT reduces the level of phosphorylated Bad, an important member of the pro-apoptotic family of proteins. Consistent with the decrease of phosphorylated Bad, cytochrome c is released from the mitochondria and caspase-9 is activated. Pretreatment of the cells with caspase-9 specific inhibitor z-LEHD-FMK or pan caspase inhibitor Ac-DEVD-CHO prevented LY294002-induced apoptosis. Of interest, p53 siRNA prevents LY294002-induced apoptosis in HTLV-1-transformed cells, suggesting that p53 reactivation is linked to apoptosis. In conclusion, the AKT pathway is involved in targeting multiple proteins which regulate caspase- and p53-dependent apoptosis in HTLV-1-transformed cells. Since AKT inhibitors simultaneously inhibit NF-kappaB and activate p53, these drugs should be promising candidates for HTLV-1-associated cancer therapy.

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Anthracycline-based chemotherapy is a common treatment for cancer patients. Because it is delivered intravenously, endothelial cells are exposed first and to the highest concentrations, prior to diffusion to target cells. Not surprisingly, vascular dysfunction is a consequence of anthracycline therapy. While chemotherapy-induced endothelial damage at administration sites has been investigated, the effects of lower doses encountered by distant microvascular networks has not. The aim of this study was to investigate the impact of epirubicin, a widely used anthracycline, on healthy endothelial cells to elucidate its effects on microvascular physiology. Here, endothelial cells were briefly exposed to low doses of epirubicin to recapitulate levels in circulation following dilution in the blood and compound half-life in circulation. Both immediate and prolonged responses to treatment were assessed to determine changes in endothelial function. Epirubicin caused a decrease in proliferation and viability in hUVEC, with lower doses resulting in a senescent phenotype in a large proportion of cells, accompanied by a significant increase in pro-inflammatory cytokines and a significant decrease in metabolic activity. Epirubicin exposure also impaired endothelial function with delayed wound closure, reduced angiogenic potential and increased monolayer permeability downstream of VE-cadherin internalization. Primary lung endothelial cells obtained from epirubicin-treated mice similarly demonstrated reduced viability and functional impairment. In vivo, epirubicin treatment resulted in persistent reduction in lung vascular density and significantly increased infiltration of myeloid cells. Modulation of endothelial status and inflammatory tissue microenvironment observed in response to low doses of epirubicin may predict risk for long-term secondary pathologies associated with chemotherapy.

To prevent cancer cells replacing and outnumbering their functional somatic counterparts, the most effective solution is their removal. Classical treatments rely on surgical excision, chemical or physical damage to the cancer cells by conventional interventions such as chemo- and radiotherapy, to eliminate or reduce tumour burden. Cancer treatment has in the last two decades seen the advent of increasingly sophisticated therapeutic regimens aimed at selectively targeting cancer cells whilst sparing the remaining cells from severe loss of viability or function. These include small molecule inhibitors, monoclonal antibodies and a myriad of compounds that affect metabolism, angiogenesis or immunotherapy. Our increased knowledge of specific cancer types, stratified diagnoses, genetic and molecular profiling, and more refined treatment practices have improved overall survival in a significant number of patients. Increased survival, however, has also increased the incidence of associated challenges of chemotherapy-induced morbidity, with some pathologies developing several years after termination of treatment. Long-term care of cancer survivors must therefore become a focus in itself, such that along with prolonging life expectancy, treatments allow for improved quality of life.

No abstract

Microvascular endothelial cells (MVEC) are plastic, versatile and highly responsive cells, with morphological and functional aspects that uniquely match the tissues they supply. The response of these cells to oxygen oscillations is an essential aspect of tissue homeostasis, and is finely tuned to maintain organ function during physiological and metabolic challenges. Primary MVEC from two continuous capillary networks with distinct organ microenvironments, those of the lung and brain, were pre-conditioned at normal atmospheric (~ 21 %) and physiological (5 and 10 %) O2 levels, and subsequently used to compare organ-specific MVEC hypoxia response. Brain MVEC preferentially stabilise HIF-2α in response to hypoxia, whereas lung MVEC primarily accumulate HIF-1α ; however, this does not result in significant differences at the level of transcriptional activation of hypoxia-induced genes. Glycolytic activity is comparable between brain and lung endothelial cells, and is affected by oxygen pre-conditioning, while glucose uptake is not changed by oxygen pre-conditioning and is observed to be consistently higher in brain MVEC. Conversely, MVEC mitochondrial activity is organ-specific; brain MVEC maintain a higher relative mitochondrial spare capacity at 5% O2, but not following hyperoxic priming. If maintained at supra-physiological O2 levels, both MVEC fail to respond to hypoxia, and have severely compromised and delayed induction of the glycolytic shifts required for survival, an effect which is particularly pronounced in brain MVEC. Oxygen preconditioning also differentially shapes the composition of the mitochondrial electron transport chain (ETC) in the two MVEC populations. Lung MVEC primed at physioxia have lower levels of all ETC complexes compared to hyperoxia, an effect exacerbated by hypoxia. Conversely, brain MVEC expanded in physioxia display increased complex II (SDH) activity, which is further augmented during hypoxia. SDH activity in brain MVEC primed at 21 % O2 is ablated; upon hypoxia, this results in the accumulation of near-toxic levels of succinate in these cells. Our data suggests that, even though MVEC are primarily glycolytic, mitochondrial integrity in brain MVEC is essential for metabolic responses to hypoxia; these responses are compromised when cells are exposed to supra-physiological levels of oxygen. This work demonstrates that the study of MVEC in normal cell culture environments do not adequately represent physiological parameters found in situ, and show that the unique metabolism and function of organ-specific MVEC can be reprogrammed by external oxygen, significantly affecting the timing and degree of downstream responses.

Date Presented 03/28/20 The purpose of this study was to determine whether the HSRT predicts student success. The data was analyzed using an ordinal logistic regression and a Spearman’s rho correlation coefficient. Statistical analyses revealed that the HSRT is not a valid predictor of student success, and there is also a weak relationship between the HSRT and student success. The HSRT can be further studied with other admission tools to determine what most accurately measures student success in a graduate OT program. Primary Author and Speaker: Kathryn Kendrick Additional Authors and Speakers: Joanna Such, Aileen Burke Contributing Authors: Catherine Cavaliere, Pamela Story

Background: Analysis of DNA methylation profiles may be useful for developing novel tumor classifications and identifying potential early detection markers. Several studies have measured methylation of CpG islands in endometrial cancer but analyses were mainly limited to small sets of candidate genes. Methods: We conducted methylation profiling on 166 representative paraffin embedded endometrial cancer tissues from the Polish endometrial cancer study, a population-based case-control study conducted in Warsaw and Lodz, 2000-2003. Tissue cores of microscopically confirmed regions of well-preserved cancer were removed from formalin fixed paraffin embedded blocks using a 1.0 mm diameter needle, followed by DNA extraction and bisulfite treatment. We used the Illumina Golden Gate platform to assess CpG methylation at 1505 sites representing 807 genes from various classes, including tumor suppressor genes, oncogenes, DNA repair genes, and cell cycle control genes. After normalization and restricting the analysis to genes that showed a standard deviation of >0.15, we conducted unsupervised hierarchical clustering analysis. In addition, we analyzed candidate methylation targets in relation to histologic subtype, grade, and endometrial cancer risk factors. Replicate samples included on the arrays showed a high reproducibility of the assay. Results: DNA extracted from tissue blocks had excellent quantity and quality for methylation profiling. A third of the target genes showed consistently high methylation in all endometrial cancers, while another third had consistently low methylation levels. In total, 482 methylation targets showed a standard deviation of >0.15 across all samples. Unsupervised hierarchical clustering based on the informative subset generated four clusters with distinct methylation profiles. Preliminarily, histologic subtypes were differentially distributed across the four clusters (p=0.03). Tumor grade and endometrial cancer risk factors were unrelated to cluster membership. Of the 166 endometrial cancers tested, 36 (21%) showed strong methylation of MLH1, which encodes for a mismatch repair protein. In addition, we analyzed ten markers previously suggested as indicative of a “methylator phenotype” in colorectal cancers (CIMP), but did not find a similar entity in endometrial cancers. Conclusions: Our data indicate that there are many consistently methylated genes in endometrial cancers that might provide targets for novel early detection assays. A subset of methylation markers showed heterogeneity between cancers and was associated with different distribution of histologic subtypes. Preliminarily, methylation patterns were unrelated to age and body mass; further analyses of endometrial cancer risk factor associations are ongoing. In addition, we have preliminarily estimated that MLH1 methylation occurs in 21% of endometrial cancers in a population-based study. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2786.