Kinome Reprogramming Is a Targetable Vulnerability in ESR1 Fusion-Driven Breast Cancer.

Transcriptionally active ESR1 fusions (ESR1-TAF) are a potent cause of breast cancer endocrine therapy (ET) resistance. ESR1-TAFs are not directly druggable because the C-terminal estrogen/anti-estrogen-binding domain is replaced with translocated in-frame partner gene sequences that confer constitutive transactivation. To discover alternative treatments, a mass spectrometry (MS)-based kinase inhibitor pulldown assay (KIPA) was deployed to identify druggable kinases that are upregulated by diverse ESR1-TAFs. Subsequent explorations of drug sensitivity validated RET kinase as a common therapeutic vulnerability despite remarkable ESR1-TAF C-terminal sequence and structural diversity. Organoids and xenografts from a pan-ET-resistant patient-derived xenograft model that harbors the ESR1-e6>YAP1 TAF were concordantly inhibited by the selective RET inhibitor pralsetinib to a similar extent as the CDK4/6 inhibitor palbociclib. Together, these findings provide preclinical rationale for clinical evaluation of RET inhibition for the treatment of ESR1-TAF-driven ET-resistant breast cancer. SIGNIFICANCE: Kinome analysis of ESR1 translocated and mutated breast tumors using drug bead-based mass spectrometry followed by drug-sensitivity studies nominates RET as a therapeutic target. See related commentary by Wu and Subbiah, p. 3159.

Discovering Synergistic Compounds with BYL-719 in PI3K Overactivated Basal-like PDXs.

Basal-like triple-negative breast cancer (TNBC) tumor cells are difficult to eliminate due to resistance mechanisms that promote survival. While this breast cancer subtype has low PIK3CA mutation rates when compared to estrogen receptor-positive (ER+) breast cancers, most basal-like TNBCs have an overactive PI3K pathway due to gene amplification or high gene expression. BYL-719 is a PIK3CA inhibitor that has been found to have low drug-drug interactions, which increases the likelihood that it could be useful for combinatorial therapy. Alpelisib (BYL-719) with fulvestrant was recently approved for treating ER+ breast cancer patients whose cancer had developed resistance to ER-targeting therapy. In these studies, a set of basal-like patient-derived xenograft (PDX) models was transcriptionally defined with bulk and single-cell RNA-sequencing and clinically actionable mutation profiles defined with Oncomine mutational profiling. This information was overlaid onto therapeutic drug screening results. BYL-719-based, synergistic two-drug combinations were identified with 20 different compounds, including everolimus, afatinib, and dronedarone, which were also found to be effective at minimizing tumor growth. These data support the use of these drug combinations towards cancers with activating PIK3CA mutations/gene amplifications or PTEN deficient/PI3K overactive pathways.

Transcriptomic changes underlying EGFR inhibitor resistance in human and mouse models of basal-like breast cancer.

The goals of this study were to identify transcriptomic changes that arise in basal-like breast cancer cells during the development of resistance to epidermal growth factor receptor inhibitors (EGFRi) and to identify drugs that are cytotoxic once EGFRi resistance occurs. Human patient-derived xenografts (PDXs) were grown in immunodeficient mice and treated with a set of EGFRi; the EGFRi erlotinib was selected for more expansive in vivo studies. Single-cell RNA sequencing was performed on mammary tumors from the basal-like PDX WHIM2 that was treated with vehicle or erlotinib for 9 weeks. The PDX was then subjected to long-term erlotinib treatment in vivo. Through serial passaging, an erlotinib-resistant subline of WHIM2 was generated. Bulk RNA-sequencing was performed on parental and erlotinib-resistant tumors. In vitro high-throughput drug screening with > 500 clinically used compounds was performed on parental and erlotinib-resistant cells. Previously published bulk gene expression microarray data from MMTV-Wnt1 tumors were contrasted with the WHIM2 PDX data. Erlotinib effectively inhibited WHIM2 tumor growth for approximately 4 weeks. Compared to untreated cells, single-cell RNA sequencing revealed that a greater proportion of erlotinib-treated cells were in the G1 phase of the cell cycle. Comparison of WHIM2 and MMTV-Wnt1 gene expression data revealed a set of 38 overlapping genes that were differentially expressed in the erlotinib-resistant WHIM2 and MMTV-Wnt1 tumors. Comparison of all three data types revealed five genes that were upregulated across all erlotinib-resistant samples: IL19, KLK7, LCN2, SAA1, and SAA2. Of these five genes, LCN2 was most abundantly expressed in triple-negative breast cancers, and its knockdown restored erlotinib sensitivity in vitro. Despite transcriptomic differences, parental and erlotinib-resistant WHIM2 displayed similar responses to the majority of drugs assessed for cytotoxicity in vitro. This study identified transcriptomic changes arising in erlotinib-resistant basal-like breast cancer. These data could be used to identify a biomarker or develop a gene signature predictive of patient response to EGFRi. Future studies should explore the predictive capacity of these gene signatures as well as how LCN2 contributes to the development of EGFRi resistance.

Exploitation of Sulfated Glycosaminoglycan Status for Precision Medicine of Triplatin in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking targetable biomarkers. TNBC is known to be most aggressive and when metastatic is often drug-resistant and uncurable. Biomarkers predicting response to therapy improve treatment decisions and allow personalized approaches for patients with TNBC. This study explores sulfated glycosaminoglycan (sGAG) levels as a predictor of TNBC response to platinum therapy. sGAG levels were quantified in three distinct TNBC tumor models, including cell line-derived, patient-derived xenograft (PDX) tumors, and isogenic models deficient in sGAG biosynthesis. The in vivo antitumor efficacy of Triplatin, a sGAG-directed platinum agent, was compared in these models with the clinical platinum agent, carboplatin. We determined that >40% of TNBC PDX tissue microarray samples have high levels of sGAGs. The in vivo accumulation of Triplatin in tumors as well as antitumor efficacy of Triplatin positively correlated with sGAG levels on tumor cells, whereas carboplatin followed the opposite trend. In carboplatin-resistant tumor models expressing high levels of sGAGs, Triplatin decreased primary tumor growth, reduced lung metastases, and inhibited metastatic growth in lungs, liver, and ovaries. sGAG levels served as a predictor of Triplatin sensitivity in TNBC. Triplatin may be particularly beneficial in treating patients with chemotherapy-resistant tumors who have evidence of residual disease after standard neoadjuvant chemotherapy. More effective neoadjuvant and adjuvant treatment will likely improve clinical outcome of TNBC.

Genomic screening reveals ubiquitin-like modifier activating enzyme 1 as a potent and druggable target in c-MYC-high triple negative breast cancer models.

Triple negative breast cancer (TNBC) accounts for over 30% of all breast cancer (BC)-related deaths, despite accounting for only 10% to 15% of total BC cases. Targeted therapy development has largely stalled in TNBC, underlined by a lack of traditionally druggable addictions like receptor tyrosine kinases (RTKs). Here, through full genome CRISPR/Cas9 screening of TNBC models, we have uncovered the sensitivity of TNBCs to the depletion of the ubiquitin-like modifier activating enzyme 1 (UBA1). Targeting UBA1 with the first-in-class UBA1 inhibitor TAK-243 induced unresolvable endoplasmic reticulum (ER)-stress and activating transcription factor 4 (ATF4)-mediated upregulation of proapoptotic NOXA, leading to cell death. c-MYC expression correlates with TAK-243 sensitivity and cooperates with TAK-243 to induce a stress response and cell death. Importantly, there was an order of magnitude greater sensitivity of TNBC lines to TAK-243 compared to normal tissue-derived cells. In five patient derived xenograft models (PDXs) of TNBC, TAK-243 therapy led to tumor inhibition or frank tumor regression. Moreover, in an intracardiac metastatic model of TNBC, TAK-243 markedly reduced metastatic burden, indicating UBA1 is a potential new target in TNBC expressing high levels of c-MYC.

Evaluation of the Effect of Hypericum triquetrifolium Turra on Memory Impairment Induced by Chronic Psychosocial Stress in Rats: Role of BDNF.

BACKGROUND: Chronic psychosocial stress impairs memory function and leads to a depression-like phenotype induced by a persistent status of oxidative stress. Hypericum perforatum L. (St. John's wort) is widely used to relieve symptoms of anxiety and depression; however, its long-term use is associated with adverse effects. Hypericum triquetrifolium Turra is closely related to H. perforatum. Both plants belong to Hypericaceae family and share many biologically active compounds. Previous work by our group showed that methanolic extracts of H. triquetrifolium have potent antioxidant activity as well as high hypericin content, a component that proved to have stress-relieving and antidepressant effects by other studies. Therefore, we hypothesized that H. triquetrifolium would reduce stress-induced cognitive impairment in a rat model of chronic stress. OBJECTIVE: To determine whether chronic treatment with H. triquetrifolium protects against stress-associated memory deficits and to investigate a possible mechanism. METHODS: The radial arm water maze (RAWM) was used to test learning and memory in rats exposed to daily stress using the resident-intruder paradigm. Stressed and unstressed rats received chronic H. triquetrifolium or vehicle. We also measured levels of brain-derived neurotrophic factor (BDNF) in the hippocampus, cortex and cerebellum. RESULTS: Neither chronic stress nor chronic H. triquetrifolium administration affected performance during acquisition. However, memory tests in the RAWM showed that chronic stress impaired different post-encoding memory stages. H. triquetrifolium prevented this impairment. Furthermore, hippocampal BDNF levels were markedly lower in stressed animals than in unstressed animals, and chronic administration of H triquetrifolium chronic administration protected against this reduction. No significant difference was observed in the effects of chronic stress and/or H. triquetrifolium treatment on BDNF levels in the cerebellum and cortex. CONCLUSION: H. triquetrifolium extract can oppose stress-associated hippocampus-dependent memory deficits in a mechanism that may involve BDNF in the hippocampus.

Identification of synergistic drug combinations using breast cancer patient-derived xenografts.

Compared with other breast cancer subtypes, triple-negative breast cancer (TNBC) is associated with relatively poor outcomes due to its metastatic propensity, frequent failure to respond to chemotherapy, and lack of alternative, targeted treatment options, despite decades of major research efforts. Our studies sought to identify promising targeted therapeutic candidates for TNBC through in vitro screening of 1,363 drugs in patient-derived xenograft (PDX) models. Using this approach, we generated a dataset that can be used to assess and compare responses of various breast cancer PDXs to many different drugs. Through a series of further drug screening assays and two-drug combination testing, we identified that the combination of afatinib (epidermal growth factor receptor (EGFR) inhibitor) and YM155 (inhibitor of baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5; survivin) expression) is synergistically cytotoxic across multiple models of basal-like TNBC and reduces PDX mammary tumor growth in vivo. We found that YM155 reduces EGFR expression in TNBC cells, shedding light on its potential mechanism of synergism with afatinib. Both EGFR and BIRC5 are highly expressed in basal-like PDXs, cell lines, and patients, and high expression of both genes reduces metastasis-free survival, suggesting that co-targeting of these proteins holds promise for potential clinical success in TNBC.

The utility of the "Glowing Head" mouse for breast cancer metastasis research.

The expression of cellular reporters to label cancer cells, such as green fluorescent protein (GFP) and luciferase, can stimulate immune responses and effect tumor growth. Recently, a mouse model that expresses GFP and luciferase in the anterior pituitary gland was generated to tolerize mice to these proteins; the "Glowing Head" mouse. Mice were obtained from a commercial vendor, bred, and then used for tumor growth and metastasis studies. The transgene expression of luciferase was assessed within tumor-naïve mice as well as mice with mammary tumors or metastases. Tumor-free mice with white fur, compared to black fur, allowed for stronger luciferase transgene expression to be observed in the pituitary, sternum, and femur. Growth of four different luciferase-expressing mouse cancer cell lines readily occurred in the mammary gland. Though sternum expression of the luciferase transgene occurred in cancer-free mice, growth or death of luciferase positive cancer cells in the lung could be observed. Liver metastases seeded by portal vein injections of luciferase positive cancer cell lines were completely distinct from luciferase transgene expression. Though lung and brain metastasis studies have limitations, the Glowing Head mouse can be useful to inhibit immune system rejection of luciferase or GFP expressing cancer cells. This mouse model is most beneficial for studies of mammary tumors and liver metastases.

Quantitative assessment of breast cancer liver metastasis expansion with patient-derived xenografts.

Advanced breast cancer often spreads to the bone, brain, liver, and lungs. The survival time of a patient with breast cancer liver metastasis is often less than 9 months without treatment. Experimental model systems often focus on the lung as a site of metastatic relapse, and therefore, there is less of an understanding of the biological processes that occur during expansive liver metastasis growth. In these studies, 14 genetically distinct breast cancer patient-derived xenografts (PDXs) were characterized for growth in the liver after portal vein injection of cancer cells. Growth in the liver occurred in 12 of 14 models, and the relative growth rate across the PDXs was overall similar to growth in the mammary gland. Pathological and immunohistochemical analyses revealed that the proliferation rates of metastases were relatively similar as the metastases expanded until the tumors became necrotic, and then slightly lower proliferation rates were observed. There were influxes of macrophages and neutrophils as the metastases increased in size, suggesting these innate immune cells may result in differential responses to therapeutics in micrometastases compared to macrometastases. The development and characterization of these models is important as future studies can utilize this information to determine if targeted therapies can slow the progression of metastatic disease at different stages in the liver.

Separation of breast cancer and organ microenvironment transcriptomes in metastases.

BACKGROUND: The seed and soil hypothesis was proposed over a century ago to describe why cancer cells (seeds) grow in certain organs (soil). Since then, the genetic properties that define the cancer cells have been heavily investigated; however, genomic mediators within the organ microenvironment that mediate successful metastatic growth are less understood. These studies sought to identify cancer- and organ-specific genomic programs that mediate metastasis. METHODS: In these studies, a set of 14 human breast cancer patient-derived xenograft (PDX) metastasis models was developed and then tested for metastatic tropism with two approaches: spontaneous metastases from mammary tumors and intravenous injection of PDX cells. The transcriptomes of the cancer cells when growing as tumors or metastases were separated from the transcriptomes of the microenvironment via species-specific separation of the genomes. Drug treatment of PDX spheroids was performed to determine if genes activated in metastases may identify targetable mediators of viability. RESULTS: The experimental approaches that generated metastases in PDX models were identified. RNA sequencing of 134 tumors, metastases, and normal non-metastatic organs identified cancer- and organ-specific genomic properties that mediated metastasis. A common genomic response of the liver microenvironment was found to occur in reaction to the invading PDX cells. Genes within the cancer cells were found to be either transiently regulated by the microenvironment or permanently altered due to clonal selection of metastatic sublines. Gene Set Enrichment Analyses identified more than 400 gene signatures that were commonly activated in metastases across basal-like PDXs. A Src signaling signature was found to be extensively upregulated in metastases, and Src inhibitors were found to be cytotoxic to PDX spheroids. CONCLUSIONS: These studies identified that during the growth of breast cancer metastases, there were genomic changes that occurred within both the cancer cells and the organ microenvironment. We hypothesize that pathways upregulated in metastases are mediators of viability and that simultaneously targeting changes within different cancer cell pathways and/or different tissue compartments may be needed for inhibition of disease progression.

Sphingosine kinase 1 activation by estrogen receptor α36 contributes to tamoxifen resistance in breast cancer.

In breast cancer, 17ß-estradiol (E2) plays critical roles mainly by binding to its canonical receptor, estrogen receptor (ER) α66, and eliciting genomic effects. E2 also triggers rapid, nongenomic responses. E2 activates sphingosine kinase 1 (SphK1), increasing sphingosine-1-phosphate (S1P) that binds to its receptors, leading to important breast cancer signaling. However, the E2 receptor responsible for SphK1 activation has not yet been identified. Here, we demonstrate in triple-negative breast cancer cells, which lack the canonical ERα66 but express the novel splice variant ERα36, that ERα36 is the receptor responsible for E2-induced activation of SphK1 and formation and secretion of S1P and dihydro-S1P, the ligands for S1PRs. Tamoxifen, the first-line endocrine therapy for breast cancer, is an antagonist of ERα66, but an agonist of ERα36, and, like E2, activates SphK1 and markedly increases secretion of S1P. A major problem with tamoxifen therapy is development of acquired resistance. We found that tamoxifen resistance correlated with increased SphK1 and ERα36 expression in tamoxifen-resistant breast cancer cells, in patient-derived xenografts, and in endocrine-resistant breast cancer patients. Our data also indicate that targeting this ERα36 and SphK1 axis may be a therapeutic option to circumvent endocrine resistance and improve patient outcome.

Chromosomal damage at bone-marrow cells is induced by exposure of rats to waterpipe water filtrate.

Waterpipe smoking is continuing to spread globally. The aim of this study is to investigate the effect of waterpipe water filtrate on chromosomal integrity in the bone-marrow cells of rats. Chromosomal damage was examined using in vivo chromosomal aberrations (CAs) and SCEs assays. Young Wistar male rats were exposed to WWF via drinking water. Chromosomal damage was measured in bone marrow cells after 6 weeks of treatment using fluorescent-plus-Giemsa staining. Treatment of rats with waterpipe water filtrate for 6 weeks did not affect food/liquid consumption and gain in body weight. The results showed that waterpipe water filtrate increased the frequencies of chromosomal breaks and exchanges by more than 30% (p < 0.01). In addition, waterpipe water filtrate significantly increased SCEs in the bone-marrow cells of rats. In conclusion, waterpipe water filtrate contains genotoxic compounds providing additional evidence for genotoxicity of waterpipe smoke.

Characterizing the efficacy of cancer therapeutics in patient-derived xenograft models of metastatic breast cancer.

PURPOSE: Basal-like breast cancers are aggressive and often metastasize to vital organs. Treatment is largely limited to chemotherapy. This study aims to characterize the efficacy of cancer therapeutics in vitro and in vivo within the primary tumor and metastatic setting, using patient-derived xenograft (PDX) models. METHODS: We employed two basal-like, triple-negative PDX models, WHIM2 and WHIM30. PDX cells, obtained from mammary tumors grown in mice, were treated with twelve cancer therapeutics to evaluate their cytotoxicity in vitro. Four of the effective drugs-carboplatin, cyclophosphamide, bortezomib, and dacarbazine-were tested in vivo for their efficacy in treating mammary tumors, and metastases generated by intracardiac injection of tumor cells. RESULTS: RNA sequencing showed that global gene expression of PDX cells grown in the mammary gland was similar to those tested in culture. In vitro, carboplatin was cytotoxic to WHIM30 but not WHIM2, whereas bortezomib, dacarbazine, and cyclophosphamide were cytotoxic to both lines. Yet, these drugs were ineffective in treating both primary and metastatic WHIM2 tumors in vivo. Carboplatin and cyclophosphamide were effective in treating WHIM30 mammary tumors and reducing metastatic burden in the brain, liver, and lungs. WHIM2 and WHIM30 metastases showed distinct patterns of cytokeratin and vimentin expression, regardless of treatment, suggesting that different tumor cell subpopulations may preferentially seed in different organs. CONCLUSIONS: This study highlights the utility of PDX models for studying the efficacy of therapeutics in reducing metastatic burden in specific organs. The differential treatment responses between two PDX models of the same intrinsic subtype, in both the primary and metastatic setting, recapitulates the challenges faced in treating cancer patients and highlights the need for combination therapies and predictive biomarkers.

Live Cell Mass Accumulation Measurement Non-Invasively Predicts Carboplatin Sensitivity in Triple-Negative Breast Cancer Patient-Derived Xenografts.

Prompt and repeated assessments of tumor sensitivity to available therapeutics could reduce patient morbidity and mortality by quickly identifying therapeutic resistance and optimizing treatment regimens. Analysis of changes in cancer cell biomass has shown promise in assessing drug sensitivity and fulfilling these requirements. However, a major limitation of previous studies in solid tumors, which comprise 90% of cancers, is the use of cancer cell lines rather than freshly isolated tumor material. As a result, existing biomass protocols are not obviously extensible to real patient tumors owing to potential artifacts that would be generated by the removal of cells from their microenvironment and the deleterious effects of excision and purification. In this present work, we show that simple excision of human triple-negative breast cancer (TNBC) tumors growing in immunodeficient mouse, patient-derived xenograft (PDX) models, followed by enzymatic disaggregation into single cell suspension, is enabling for rapid and accurate biomass accumulation-based predictions of in vivo sensitivity to the chemotherapeutic drug carboplatin. We successfully correlate in vitro biomass results with in vivo treatment results in three TNBC PDX models that have differential sensitivity to this drug. With a maximum turnaround time of 40 h from tumor excision to useable results and a fully-automated analysis pipeline, the assay described here has significant potential for translation to clinical practice.

Combining restricted diet with forced or voluntary exercises improves hippocampal BDNF and cognitive function in rats.

Dietary restriction (RDt) and exercise (Ex) enhances cognitive function due, at least in part, levels of neurotrophins such as brain-derived neurotrophic factor (BDNF). This study examined changes in BDNF levels and data acquisition and retention following every-other-day RDt alone, and combined with either voluntary wheel (VxRDt) or forced swimming Exs (FxRDt) in rats. Hippocampal BDNF was measured using ELISA while learning and memory formation were assessed with the radial arm water maze (RAWM) paradigm. After 6 weeks, VxRDt and FxRDt enhanced BDNF levels, and short- and long-term memories (p < 0.05). The magnitude of the increase in BDNF was significantly higher in VxRDt group than in other groups (p < 0.05). However, no differences were found in learning and memory formation between the Ex regiments (VxRDt versus FxRDt). Additionally, RDt alone neither modulated BDNF level nor enhanced learning and memory formation (p > 0.05). These results suggest more important role of Ex, as opposed to RDt, in enhancing learning and memory formation. In addition, VxRDt appears to be more potent in enhancing brain BDNF levels than FxRDt, when combined with RDt in rats.

Suppression of miR-184 in malignant gliomas upregulates SND1 and promotes tumor aggressiveness.

BACKGROUND: Malignant glioma is an aggressive cancer requiring new therapeutic targets. MicroRNAs (miRNAs) regulate gene expression post transcriptionally and are implicated in cancer development and progression. Deregulated expressions of several miRNAs, specifically hsa-miR-184, correlate with glioma development. METHODS: Bioinformatic approaches were used to identify potential miR-184-regulated target genes involved in malignant glioma progression. This strategy identified a multifunctional nuclease, SND1, known to be overexpressed in multiple cancers, including breast, colon, and hepatocellular carcinoma, as a putative direct miR-184 target gene. SND1 levels were evaluated in patient tumor samples and human-derived cell lines. We analyzed invasion and signaling in vitro through SND1 gain-of-function and loss-of-function. An orthotopic xenograft model with primary glioma cells demonstrated a role of miR-184/SND1 in glioma pathogenesis in vivo. RESULTS: SND1 is highly expressed in human glioma tissue and inversely correlated with miR-184 expression. Transfection of glioma cells with a miR-184 mimic inhibited invasion, suppressed colony formation, and reduced anchorage-independent growth in soft agar. Similar phenotypes were evident when SND1 was knocked down with siRNA. Additionally, knockdown (KD) of SND1 induced senescence and improved the chemoresistant properties of malignant glioma cells. In an orthotopic xenograft model, KD of SND1 or transfection with a miR-184 mimic induced a less invasive tumor phenotype and significantly improved survival of tumor bearing mice. CONCLUSIONS: Our study is the first to show a novel regulatory role of SND1, a direct target of miR-184, in glioma progression, suggesting that the miR-184/SND1 axis may be a useful diagnostic and therapeutic tool for malignant glioma.

Astrocyte elevated gene-1 interacts with Akt isoform 2 to control glioma growth, survival, and pathogenesis.

The oncogene astrocyte elevated gene-1 (AEG-1; MTDH) is highly expressed in glioblastoma multiforme (GBM) and many other types of cancer, where it activates multiple signaling pathways that drive proliferation, invasion, angiogenesis, chemoresistance, radioresistance, and metastasis. AEG-1 activates the Akt signaling pathway and Akt and c-Myc are positive regulators of AEG-1 transcription, generating a positive feedback loop between AEG-1 and Akt in regulating tumorigenesis. Here, we describe in GBM cells a direct interaction between an internal domain of AEG-1 and the PH domain of Akt2, a major driver in GBM. Expression and interaction of AEG-1 and Akt2 are elevated in GBM and contribute to tumor cell survival, proliferation, and invasion. Clinically, in silico gene expression and immunohistochemical analyses of patient specimens showed that AEG-1 and Akt2 expression correlated with GBM progression and reduced patient survival. AEG-1-Akt2 interaction prolonged stabilization of Akt2 phosphorylation at S474, regulating downstream signaling cascades that enable cell proliferation and survival. Disrupting AEG-1-Akt2 interaction by competitive binding of the Akt2-PH domain led to reduced cell viability and invasion. When combined with AEG-1 silencing, conditional expression of Akt2-PH markedly increased survival in an orthotopic mouse model of human GBM. Our study uncovers a novel molecular mechanism by which AEG-1 augments glioma progression and offers a rationale to block AEG-1-Akt2 signaling function as a novel GBM treatment.

Forced and voluntary exercises equally improve spatial learning and memory and hippocampal BDNF levels.

Multiple evidence suggest the importance of exercise for cognitive and brain functions. Few studies however, compared the behavioral and neural adaptations to force versus voluntary exercise training. Therefore, spatial learning and memory formation and brain-derived neurotrophic factor (BDNF) were examined in Wister male rats after 6 weeks of either daily forced swimming, voluntary running exercises, or sedentary. Learning capabilities and short, 5-hour, and long term memories improved (p<0.05) similarly in the exercise groups, without changes (p>0.05) in the sedentary. Likewise, both exercises resulted in increased (p<0.05) hippocampal BDNF level. The results suggest that forced and voluntary exercises can similarly enhance cognitive- and brain-related tasks, seemingly vie the BDNF pathway. These data further confirm the health benefits of exercise and advocate both exercise modalities to enhance behavioral and neural functions.

Changes in spatial memory and BDNF expression to simultaneous dietary restriction and forced exercise.

Previous literature suggests that learning and memory formation can be influenced by diet and exercise. In the current study, we investigated the combined effects of forced swimming exercise (FSE) and every other day fasting (EODF) on spatial memory formation and on the levels of brain-derived neurotrophic factor (BDNF) in the hippocampus of Wistar male rats. The radial arm water maze (RAWM) paradigm was used to assess changes in learning and memory formation, whereas ELISA assay was used to measure BDNF protein levels. The FSE and/or EODF were simultaneously instituted for 6 weeks. Results show that FSE improved learning, short-term as well as long-term memory formation, and significantly increased BDNF protein in the hippocampus (p<0.05). However, EODF had no effect on either spatial learning and memory formation or the levels of hippocamapal BDNF protein (p>0.05). In addition, EODF did not modulate beneficial effect of swimming exercise on cognitive function (p>0.05). Thus exercise enhanced, while EODF did not affect spatial learning and memory formation.

Changes in spatial memory and BDNF expression to concurrent dietary restriction and voluntary exercise.

Substantial data suggest that cognitive function can be influenced by many lifestyle activities associated with changes in energy metabolism such as exercise and diet. In the current study, we investigated the combined effects of voluntary exercise (access to running wheels) and dietary restriction (every other day fasting, EODF) on spatial memory formation and on the levels of brain-derived neurotrophic factor (BDNF) in the hippocampus of Wistar male rats. Spatial learning and memory formation was assessed using the radial arm water maze (RAWM) paradigm, while BDNF protein was measured using ELISA test. Voluntary exercise and/or EODF were instituted for 6 weeks. Voluntary exercise alone significantly enhanced short-term, intermediate-term, and long-term memory formation, and increased BDNF protein levels in the hippocampus. EODF enhanced mean running wheel activity by approximately twofold. However, EODF did not modulate the effects of exercise on memory formation and expression of BDNF. In addition, EODF alone had no effect on memory and BDNF protein in the hippocampus. In conclusion, results of this study indicate that exercise enhanced while EODF had neutral effect on both spatial memory formation and hippocampus BDNF levels.