A hierarchical approach employing metabolic and gene expression profiles to identify the pathways that confer cytotoxicity in HepG2 cells

<p>Abstract</p> <p>Background</p> <p>Free fatty acids (FFA) and tumor necrosis factor alpha (TNF-α) have been implicated in the pathogenesis of many obesity-related metabolic disorders. When human hepatoblastoma cells (HepG2) were exposed to different types of FFA and TNF-α, saturated fatty acid was found to be cytotoxic and its toxicity was exacerbated by TNF-α. In order to identify the processes associated with the toxicity of saturated FFA and TNF-α, the metabolic and gene expression profiles were measured to characterize the cellular states. A computational model was developed to integrate these disparate data to reveal the underlying pathways and mechanisms involved in saturated fatty acid toxicity.</p> <p>Results</p> <p>A hierarchical framework consisting of three stages was developed to identify the processes and genes that regulate the toxicity. First, discriminant analysis identified that fatty acid oxidation and intracellular triglyceride accumulation were the most relevant in differentiating the cytotoxic phenotype. Second, gene set enrichment analysis (GSEA) was applied to the cDNA microarray data to identify the transcriptionally altered pathways and processes. Finally, the genes and gene sets that regulate the metabolic responses identified in step 1 were identified by integrating the expression of the enriched gene sets and the metabolic profiles with a multi-block partial least squares (MBPLS) regression model.</p> <p>Conclusion</p> <p>The hierarchical approach suggested potential mechanisms involved in mediating the cytotoxic and cytoprotective pathways, as well as identified novel targets, such as NADH dehydrogenases, aldehyde dehydrogenases 1A1 (ALDH1A1) and endothelial membrane protein 3 (EMP3) as modulator of the toxic phenotypes. These predictions, as well as, some specific targets that were suggested by the analysis were experimentally validated.</p

Serum Adiponectin, Resistin, and Circulating Soluble Receptor for Advanced Glycation End Products in Colectomy Patients

Aim. Surgical trauma and associated complications are frequently related to physiological stress during colectomy. This study evaluated the response of adiponectin, resistin, and circulating soluble receptor for advanced glycation end products (sRAGE) in colectomy patients with or without an enhanced recovery protocol. Method. Serum samples were collected from 44 colectomy patients at 3 timframes. The surgical procedures were laparoscopic (LAP), hand-assisted laparoscopic (HALS), or open colectomy (OPEN). Adiponectin, resistin, and sRAGE levels were determined by ELISA. Repeated measures ANOVA was applied and P values < 0.05 were considered significant. Results. A total of 132 (44 × 3) sera were used for analysis. Levels of adiponectin was significantly decreased between PREOP and POD3 (P < 0.001). Conversely, concentrations of resistin significantly increased from PREOP to POD1 and returned to baseline value by POD3 (P < 0.001). Serum sRAGE levels were significantly higher in LAP in comparison with HALS (P = 0.004) and OPEN (P < 0.001). sRAGE levels were significantly higher in sera of patients that underwent ERP (P < 0.001). Conclusions. Serum adiponectin, resistin, and sRAGE have the potential to develop into a panel of stress markers. Higher sRAGE levels in sera of LAP and ERP patients may be indicative of a protective and syngeristic role for colectomy recovery

LRP5 and LRP6 Are Not Required for Protective Antigen–Mediated Internalization or Lethality of Anthrax Lethal Toxin

Anthrax toxin (AnTx) plays a key role in the pathogenesis of anthrax. AnTx is composed of three proteins: protective antigen (PA), edema factor, and lethal factor (LF). PA is not toxic but serves to bind cells and translocate the toxic edema factor or LF moieties to the cytosol. Recently, the low-density lipoprotein receptor–related protein LRP6 has been reported to mediate internalization and lethality of AnTx. Based on its similarity to LRP6, we hypothesized that LRP5 may also play a role in cellular uptake of AnTx. We assayed PA-dependent uptake of anthrax LF or a cytotoxic LF fusion protein (FP59) in cells and mice harboring targeted deletions of Lrp5 or Lrp6. Unexpectedly, we observed that uptake was unaltered in the presence or absence of either Lrp5 or Lrp6 expression. Moreover, we observed efficient PA-mediated uptake into anthrax toxin receptor (ANTXR)–deficient Chinese hamster ovary cells (PR230) that had been stably engineered to express either human ANTXR1 or human ANTXR2 in the presence or absence of siRNA specific for LRP5 or LRP6. Our results demonstrate that neither LRP5 nor LRP6 is necessary for PA-mediated internalization or lethality of anthrax lethal toxin

Molecular subtype analysis determines the association of advanced breast cancer in Egypt with favorable biology

<p>Abstract</p> <p>Background</p> <p>Prognostic markers and molecular breast cancer subtypes reflect underlying biological tumor behavior and are important for patient management. Compared to Western countries, women in North Africa are less likely to be prognosticated and treated based on well-characterized markers such as the estrogen receptor (ER), progesterone receptor (PR) and Her2. We conducted this study to determine the prevalence of breast cancer molecular subtypes in the North African country of Egypt as a measure of underlying biological characteristics driving tumor manifestations.</p> <p>Methods</p> <p>To determine molecular subtypes we characterized over 200 tumor specimens obtained from Egypt by performing ER, PR, Her2, CK5/6, EGFR and Ki67 immunohistochemistry.</p> <p>Results</p> <p>Our study demonstrated that the Luminal A subtype, associated with favorable prognosis, was found in nearly 45% of cases examined. However, the basal-like subtype, associated with poor prognosis, was found in 11% of cases. These findings are in sharp contrast to other parts of Africa in which the basal-like subtype is over-represented.</p> <p>Conclusions</p> <p>Egyptians appear to have favorable underlying biology, albeit having advanced disease at diagnosis. These data suggest that Egyptians would largely profit from early detection of their disease. Intervention at the public health level, including education on the benefits of early detection is necessary and would likely have tremendous impact on breast cancer outcome in Egypt.</p

A highly invasive human glioblastoma pre-clinical model for testing therapeutics

Animal models greatly facilitate understanding of cancer and importantly, serve pre-clinically for evaluating potential anti-cancer therapies. We developed an invasive orthotopic human glioblastoma multiforme (GBM) mouse model that enables real-time tumor ultrasound imaging and pre-clinical evaluation of anti-neoplastic drugs such as 17-(allylamino)-17-demethoxy geldanamycin (17AAG). Clinically, GBM metastasis rarely happen, but unexpectedly most human GBM tumor cell lines intrinsically possess metastatic potential. We used an experimental lung metastasis assay (ELM) to enrich for metastatic cells and three of four commonly used GBM lines were highly metastatic after repeated ELM selection (M2). These GBM-M2 lines grew more aggressively orthotopically and all showed dramatic multifold increases in IL6, IL8, MCP-1 and GM-CSF expression, cytokines and factors that are associated with GBM and poor prognosis. DBM2 cells, which were derived from the DBTRG-05MG cell line were used to test the efficacy of 17AAG for treatment of intracranial tumors. The DMB2 orthotopic xenografts form highly invasive tumors with areas of central necrosis, vascular hyperplasia and intracranial dissemination. In addition, the orthotopic tumors caused osteolysis and the skull opening correlated to the tumor size, permitting the use of real-time ultrasound imaging to evaluate antitumor drug activity. We show that 17AAG significantly inhibits DBM2 tumor growth with significant drug responses in subcutaneous, lung and orthotopic tumor locations. This model has multiple unique features for investigating the pathobiology of intracranial tumor growth and for monitoring systemic and intracranial responses to antitumor agents

Exposure to Hypergravity During Pregnancy and Early Lactation Alters Abundance of Cytoskeletal and Extracellular Matrix Proteins in a Rat Model

PURPOSE: Complete functional differentiation of the mammary gland is dependent on an integral cytoskeletal support structure and hormonal direction. Furthermore, prolactin released from the brain is indispensable for initiation and maintenance of lactation in all the species so far studied. However, intact cytoskeletal architecture is pivotal for prolactin-mediated development. Therefore, the objective of this study was to determine the effects of chronic hypergravity (HG) exposure from mid-pregnancy to early lactation on pre-partum/postpartum abundance of the cellular scaffolding and connective tissue proteins in the rat mammary gland. SUBJECTS: One group of pregnant Sprague Dawley rats were exposed to either 2g (HG) or 1g (control) from days 11 to 20 of gestation (G20). Another control (1g) and experimental (2g) groups were investigated from days 11 of pregnancy through days 1 (P1) and 3 (P3) postpartum. MATERIALS AND METHODS: On G20, P1 and P3, mammary tissue was collected and processed for immunohistochemical quantification of proteins associated with cellular scaffolding (actin, tubulin cytokeratin, vimentin). RESULTS: At G20, and P3 significant (pCONCLUSION: Our results suggest that abnormal cytoskeletal protein quantities correlate with the reduced mammary metabolic activity in HG-exposed rats