Super-enhancer hijacking drives ectopic expression of hedgehog pathway ligands in meningiomas.

Hedgehog signaling mediates embryologic development of the central nervous system and other tissues and is frequently hijacked by neoplasia to facilitate uncontrolled cellular proliferation. Meningiomas, the most common primary brain tumor, exhibit Hedgehog signaling activation in 6.5% of cases, triggered by recurrent mutations in pathway mediators such as SMO. In this study, we find 35.6% of meningiomas that lack previously known drivers acquired various types of somatic structural variations affecting chromosomes 2q35 and 7q36.3. These cases exhibit ectopic expression of Hedgehog ligands, IHH and SHH, respectively, resulting in Hedgehog signaling activation. Recurrent tandem duplications involving IHH permit de novo chromatin interactions between super-enhancers within DIRC3 and a locus containing IHH. Our work expands the landscape of meningioma molecular drivers and demonstrates enhancer hijacking of Hedgehog ligands as a route to activate this pathway  in neoplasia.

Silencing of the MEG3 gene promoted anti-cancer activity and drug sensitivity in glioma.

Aberrant expression of MEG3 has been shown in various cancers. The purpose of this study is to evaluate the effect of MEG3 on glioma cells and the use of potential chemotherapeutics in glioma by modulating MEG3 expression. Cell viability, migration and chemosensitivity were assayed. Cell death was evaluated in MEG3 overexpressing and MEG3 suppressed cells. MEG3 expression was compared in patient-derived glioma cells concerning IDH1 mutation and WHO grades. Silencing of MEG3 inhibited cell proliferation and reduced cell migration while overexpression of MEG3 promoted proliferation in glioma cells. MEG3 inhibition improved the chemosensitivity of glioma cells to 5-fluorouracil (5FU) but not to navitoclax. On the other hand, there is no significant effect of MEG3 expression on temozolamide (TMZ) treatment which is a standard chemotherapeutic agent in glioma. Suppression of the MEG3 gene in patient-derived oligodendroglioma cells also showed the same effect whereas glioblastoma cell proliferation and chemosensitivity were not affected by MEG3 inhibition. Further, as a possible cell death mechanism of action apoptosis was investigated. Although MEG3 is a widely known tumour suppressor gene and its loss is associated with several cancer types, here we reported that MEG3 inhibition can be used for improving the efficiency of known chemotherapeutic drug sensitivity. We propose that the level of MEG3 should be evaluated in the treatment of different glioma subtypes that are resistant to effective drugs to increase the potential effective drug applications.

Anti-SARS-CoV-2 and cytotoxic activity of two marine alkaloids from green alga Caulerpa cylindracea Sonder in the Dardanelles.

Caulerpa cylindracea Sonder is a green alga belonging to the Caulerpaceae family. This is the first chemical investigation of C. cylindracea in the Dardanelles which resulted in the isolation of four compounds, caulerpin (1), monomethyl caulerpinate (2), beta-sitosterol (3), and palmitic acid (4). Their structures were elucidated by spectroscopic analyses including 1D- and 2D NMR and mass. The isolated compounds 1 and 2 were tested against the SARS-CoV-2 viral targets spike protein and main protease (3CL) enzyme, and both compounds significantly inhibit the interaction of spike protein and ACE2, while the main protease activity was not significantly reduced. Docking studies suggested that compounds 1 and 2 may bind to the ACE2 binding pocket on spike, and compound 2 may also bind to an allosteric site on spike. As such, these compounds may inhibit the spike-ACE2 complex formation competitively and/or allosterically and have the potential to be used against SARS-CoV-2 virus infection. In addition, compounds 1 and 2 showed at least two-fold higher cytotoxicity against breast cancer cell lines MCF7 and MDA-MB-231 compared to the CCD fibroblast control cell line.

Glycopolymer and Poly(ß-amino ester)-Based Amphiphilic Block Copolymer as a Drug Carrier.

Glycopolymers are synthetic macromolecules having pendant sugar moieties and widely utilized to target cancer cells. They are usually considered as a hydrophilic segment of amphiphilic block copolymers to fabricate micelles as drug carriers. A novel amphiphilic block copolymer, namely, poly(2-deoxy-2-methacrylamido-d-glucose-co-2-hydroxyethyl methacrylate)-b-poly(ß-amino ester) [P(MAG-co-HEMA)-b-PBAE], with active cancer cell targeting potential and pH responsivity was prepared. Tetrazine end functional P(MAG-co-HEMA) and norbornene end functional PBAE blocks were separately synthesized through reversible addition fragmentation chain transfer polymerization and Michael addition-based poly-condensation, respectively, and followed by end-group transformation. Then, inverse electron demand Diels Alder reaction between the tetrazine and the norbornene groups was performed by simply mixing to obtain the amphiphilic block copolymer. After characterization of the block copolymer in terms of chemical structure, pH responsivity, and drug loading/releasing, pH-responsive micelles were obtained with or without doxorubicin (DOX), a model anticancer drug. The micelles exhibited a sharp protonated/deprotonated transition on tertiary amine groups around pH 6.75 and the pH-specific release of DOX below this value. Eventually, the drug delivery potential was evaluated by cytotoxicity assays on both the noncancerous human umbilical vein endothelial cell (HUVEC) cell line and glioblastoma cell line, U87-MG. While the DOX-loaded polymeric micelles were not toxic in noncancerous HUVEC cells, being toxic only to the cancer cells indicates that it is a potential specific cell targeting strategy in the treatment of cancer.

A novel BH3 mimetic Bcl-2 inhibitor promotes autophagic cell death and reduces in vivo Glioblastoma tumor growth.

Anti-apoptotic members of the Bcl-2 family proteins play central roles in the regulation of cell death in glioblastoma (GBM), the most malignant type of brain tumor. Despite the advances in GBM treatment, there is still an urgent need for new therapeutic approaches. Here, we report a novel 4-thiazolidinone derivative BH3 mimetic, BAU-243 that binds to Bcl-2 with a high affinity. BAU-243 effectively reduced overall GBM cell proliferation including a subpopulation of cancer-initiating cells in contrast to the selective Bcl-2 inhibitor ABT-199. While ABT-199 successfully induces apoptosis in high BCL2-expressing neuroblastoma SHSY-5Y cells, BAU-243 triggered autophagic cell death rather than apoptosis in GBM A172 cells, indicated by the upregulation of BECN1, ATG5, and MAP1LC3B expression. Lc3b-II, a potent autophagy marker, was significantly upregulated following BAU-243 treatment. Moreover, BAU-243 significantly reduced tumor growth in vivo in orthotopic brain tumor models when compared to the vehicle group, and ABT-199 treated animals. To elucidate the molecular mechanisms of action of BAU-243, we performed computational modeling simulations that were consistent with in vitro results. Our results indicate that BAU-243 activates autophagic cell death by disrupting the Beclin 1:Bcl-2 complex and may serve as a potential small molecule for treating GBM.

IDH1 mutation activates mTOR signaling pathway, promotes cell proliferation and invasion in glioma cells.

BACKGROUND: Glioma is the most common type of brain tumors and isocitrate dehydrogenase (IDH1) gene is the most prominent molecular marker about the disease prognosis, response to therapy and patient survival. There are conflicting data about the effect of IDH1 mutation on glial cell proliferation, invasion and migration characteristics. The effect of IDH1 mutation on mTOR signaling pathway, which has key roles in tumorigenesis process, is limited and previous data is controversial. We aimed to explore the effect of wild type and mutant IDH1 overexpression on glioma cells and investigated the correlation with mTOR signaling pathway associated genes. METHODS AND RESULTS: U87-MG and A172 cells were transfected with different IDH1 mutant gene overexpressing (R132H, R132L, R132S, R132C) viral vectors. Cell proliferation, cell invasion and migration analysis as well as quantitative PCR analysis with the mutant glioma cell lines were performed. Forty-two patient derived glioma cells were obtained from patients with different glioma subtypes and cancer cells were enriched by culturing cells. Overexpression of both mutant and wild type IDH1 gene promoted the cell proliferation, but only IDH1 mutation increased cell invasion and migration. The expression of IDH1 mutation activated mTOR signaling via upregulation of WNTA, PRKAA2, GSK3B and MTOR genes as well as phosphorylated mTOR protein level. CONCLUSIONS: Our results highlighted IDH1 mutation upregulate mTOR signaling pathway and promote cell proliferation, invasion and migration.

Antiangiogenic Molecules Suppressed Meningioma-Induced Neovascularization: A Corneal Angiogenesis Study.

AIM: To investigate the angiogenic effects of bevacizumab and imatinib on different meningioma tissue grades. MATERIAL AND METHODS: In this study, in silico analysis of angiogenesis-related gene expression was carried out using previously reported datasets. Messenger ribonucleic acid expressions of VEGFA, VEGFB, PDGFRA, and PDGFRB genes were obtained from two different meningioma transcriptome datasets. The effect of antiangiogenic drugs, bevacizumab and imatinib, on meningiomainduced vascularization was assessed by using rat corneal angiogenesis assay (CAA). RESULTS: Bevacizumab and imatinib both significantly reduced meningioma-induced neovascularization in the CAA model. CONCLUSION: The angiogenic characteristics of meningiomas may be suppressed by using antiangiogenic drugs to prevent neovascularization, thus improving prognosis.

Hybrid In Silico and TR-FRET-Guided Discovery of Novel BCL-2 Inhibitors.

B-Cell lymphoma 2 (BCL-2) regulates cell death in humans. In this study, combined multiscale in silico approaches and in vitro studies were employed. A small-molecule library that includes more than 210 000 compounds was used. The predicted therapeutic activity value (TAV) of the compounds in this library was computed with the binary cancer quantitative structure-activity relationships (QSAR) model. The molecules with a high calculated TAV were used in 26 individual toxicity QSAR models. As a result of this screening protocol, 288 nontoxic molecules with high predicted TAV were identified. These selected hits were then screened against the BCL-2 target protein using hybrid docking and molecular dynamics (MD) simulations. The interaction energies of identified compounds were compared with two known BCL-2 inhibitors. Then, the short MD simulations were carried out by initiating the best docking poses of 288 molecules. Average MM/GBSA energies were computed, and long MD simulations were employed to selected hits. The same calculations were also applied for two known BCL-2 inhibitors. Moreover, a five-site (AHRRR) structure-based pharmacophore model was constructed, and this model was used in the screening of the same database. On the basis of hybrid data-driven ligand identification study, final hits were selected and used in in vitro studies. Based on results of the time-resolved fluorescence resonance energy transfer (TR-FRET) analysis, further filtration was carried out for the U87-MG cell line tests. MTT cell proliferation assay analysis results showed that selected three potent compounds were significantly effective on glioma cells.

Association of MTHFR, MTRR and RAD54L Gene Variations with Meningioma and Correlation with Tumor's Histopathological Characteristics on Turkish Cohort.

AIM: To elucidate the association of the MTHFR, MTRR, and RAD54L gene variations with meningioma in Turkish cohort. MATERIAL AND METHODS: DNAs were isolated from 87 retrospective meningioma samples. The MTHFR, MTRR, and RAD54L gene hotspot regions were amplified with specific primers via polymerase chain reaction (PCR), and next-generation sequencing (NGS) was performed. All the detected variations and single-nucleotide polymorphisms (SNPs) were listed and compared with healthy control frequencies in different genomic databases. The histopathological characteristics of meningiomas and genomic variations were compared. Pearson?s chi-squared test was used to detect the statistical differences of SNPs, and correlation analysis was conducted. RESULTS: rs1801131, rs1801133, and rs4846051 on MTHFR, rs1801394 on MTRR, and rs1048771 on RAD54L gene frequencies were found to be significantly altered in the overall cohort of 87 patients with meningioma. The frequency of rs18011031 is 0.09 in the meningioma cohort, which is significantly correlated with WHO tumor grades (p = 0.038). The frequency of rs18011033 is 0.29 in the meningioma cohort, which is significantly correlated with WHO tumor grades (p = 0.045). Furthermore, the frequency of rs4846051 is 0.18 in the meningioma cohort, which is significantly correlated with WHO tumor grades (p = 0.023) and also with low Ki67 proliferation index (p = 0.00455). The frequency of rs1801394 is 0.15 and significantly associated with high Ki67 proliferation index in the meningioma cohort (p = 0.0144). The frequency of rs1048771 is 0.09 in the meningioma cohort and is significantly associated with the non-necrotic histopathological form of the tumor (p = 0.05). CONCLUSION: We reported a significant association between the genetic alterations of folate metabolism (MTHFR, MTRR) and DNA repair mechanism (RAD54L) genes with the histopathological characteristics of meningioma. Five significant SNPs on these genes and four significant correlations of SNPs with histopathological characteristics were identified. This is a preliminary promising study conducted to establish the genetic marker analysis for meningioma diagnosis and prognosis for folate metabolism and DNA repair genes in Turkish cohort.

Associations of meningioma molecular subgroup and tumor recurrence.

BACKGROUND: We and others have identified mutually exclusive molecular subgroups of meningiomas; however, the implications of this classification for clinical prognostication remain unclear. Integrated genomic and epigenomic analyses implicate unique oncogenic processes associated with each subgroup, suggesting the potential for divergent clinical courses. The aim of this study was to understand the associated clinical outcomes of each subgroup, as this could optimize treatment for patients. METHODS: We analyzed outcome data for 469 meningiomas of known molecular subgroup, including extent of resection, postoperative radiation, surveillance imaging, and time to recurrence, when applicable. Statistical relationships between outcome variables and subgroup were assessed. Features previously associated with recurrence were further investigated after stratification by subgroup. We used Kaplan-Meier analyses to compare progression-free survival, and identified factors significantly associated with recurrence using Cox proportional hazards modeling. RESULTS: Meningioma molecular subgroups exhibited divergent clinical courses at 2 years of follow-up, with several aggressive subgroups (NF2, PI3K, HH, tumor necrosis factor receptor-associated factor 7 [TRAF7]) recurring at an average rate of 22 times higher than others (KLF4, POLR2A, SMARCB1). PI3K-activated tumors recurred earlier than other subgroups but had intermediate long-term outcome. Among low-grade tumors, HH and TRAF7 meningiomas exhibited elevated recurrence compared with other subgroups. Recurrence of NF2 tumors was associated with male sex, high grade, and elevated Ki-67. Multivariate analysis identified molecular subgroup as an independent predictor of recurrence, along with grade and previous recurrence. CONCLUSION: We describe distinct clinical outcomes and recurrence rates associated with meningioma molecular subgroups. Our findings emphasize the importance of genomic characterization to guide postoperative management decisions for meningiomas.

An Integrated in silico Approach and in†vitro Study for the Discovery of Small-Molecule USP7 Inhibitors as Potential Cancer Therapies.

The ubiquitin-specific protease 7 (USP7) is a highly promising well-validated target for a variety of malignancies. USP7 is critical in regulating the tumor suppressor p53 along with numerous epigenetic modifiers and transcription factors. Previous studies showed that USP7 inhibitors led to increased levels of p53 and anti-proliferative effects in hematological and solid tumor cell lines. Thus, this study aimed to identify potent and safe USP7 hit inhibitors as potential anti-cancer therapeutics via an integrated computational approach that combines pharmacophore modeling, molecular docking, molecular dynamics (MD) simulations and post-MD free energy calculations. In this study, the crystal structure of USP7 has been extensively investigated using a combination of three different chemical pharmacophore modeling approaches. We then screened ∼220.000 drug-like small molecule library and the hit ligands predicted to be nontoxic were evaluated further. The identified hits from each pharmacophore modeling study were further examined by 1-ns short MD simulations and MM/GBSA free energy analysis. In total, we ran 1 ns MD simulations for 1137 selected on small compounds. Based on their average MM/GBSA scores, 18 ligands were selected for 50 ns MD simulations along with one highly potent USP7 inhibitor used as a positive control. The in vitro enzymatic inhibition assay testing of our lead 18 molecules confirmed that 7 of these molecules were successful in USP7 inhibition. Screening results showed that within the used screening approaches, the most successful one was structure-based pharmacophore modeling with the success rate of 75 %. The identification of potent and safe USP7 small molecules as potential inhibitors is a step closer to finding appropriate effective therapies for cancer. Our lead ligands can be used as a scaffold for further structural optimization and development, enabling further research in this promising field.

Proposing novel MDM2 inhibitors: Combined physics-driven high-throughput virtual screening and in vitro studies.

The mouse double minute 2 (MDM2) protein acts as a negative regulator of the p53 tumor suppressor. It directly binds to the N terminus of p53 and promotes p53 ubiquitination and degradation. Since the most common p53-suppressing mechanisms involve the MDM2, proposing novel inhibitors has been the focus of many in silico and also experimental studies. Thus, here we screened around 500,000 small organic molecules from Enamine database at the binding pocket of this oncogenic target. The screening was achieved systematically with starting from the high-throughput virtual screening method followed by more sophisticated docking approaches. The initial high number of screened molecules was reduced to 100 hits which then were studied extensively for their therapeutic activity and pharmacokinetic properties using binary QSAR models. The structural and dynamical profiles of the selected molecules at the binding pocket of the target were studied thoroughly by all-atom molecular dynamics simulations. The free energy of the binding of the hit molecules was estimated by the MM/GBSA method. Based on docking simulations, binary QSAR model results, and free energy calculations, 11 compounds (E1-E11) were selected for in vitro studies. HUVEC vascular endothelium, colon cancer, and breast cancer cell lines were used for testing the binding affinities of the identified hits and for further cellular effects on human cancer cell. Based on in vitro studies, six compounds (E1, E2, E5, E6, E9, and E11) in breast cancer cell lines and six compounds (E1, E2, E5, E6, E8, and E10) in colon cancer cell lines were found as active. Our results showed that these compounds inhibit proliferation and lead to apoptosis.

Development of a Rapid and Sensitive IDH1/2 Mutation Detection Method for Glial Tumors and a Comparative Mutation Analysis of 236 Glial Tumor Samples.

BACKGROUND: The presence of mutations in the isocitrate dehydrogenase 1 and 2 genes (IDH1/2) in glioma tumors is correlated with good prognosis upon standard-of-care treatment. Therefore, information on whether the glioma tumor has IDH1/2 mutations could be used in the correct diagnosis and management of glial tumors. The two most common techniques used to detect IDH1/2 mutations, immunohistochemistry (IHC) and Sanger sequencing, are prone to missing these mutations, especially if the tumor cells that carry the mutations constitute a small minority of the tumor itself. OBJECTIVES: We developed and validated a rapid method (3-mismatch-amplification refractory mutation system [3m-ARMS]) that can be used for pre-, intra- and postoperative detection of the most common IDH1/2 mutations in glial tumors with high specificity and sensitivity. We also conducted a comprehensive IDH1/2 mutation analysis in 236 glial tumor samples comparing 3m-ARMS, IHC and Sanger sequencing. METHODS: 3m-ARMS was optimized and validated for the specific and sensitive detection of the most common IDH1 and IDH2 mutations. We then analyzed 236 glial tumor samples for the presence of IDH1/2 mutations using 3m-ARMS, Sanger sequencing and IHC techniques. We then analyzed and compared the results, evaluating the diagnostic and screening potential of 3m-ARMS. RESULTS: Comparison of the three techniques used in the mutation analysis showed that 3m-ARMS-based IDH1/2 mutation detection was superior to IHC and Sanger sequencing-based IDH1/2 mutation detection in terms of accuracy, specificity and sensitivity, especially for tumor samples in which only a small minority of the cell population carried the mutation. 3m-ARMS could detect the presence of femtogram levels of IDH1/2 mutant DNA in DNA samples in which the mutant DNA-to-wild-type DNA ratio was as low as 1:100,000. CONCLUSION: Sanger sequencing and IHC-based methods have shortcomings when detecting mutations in glial tumors so can miss IDH1/2 mutations in glial tumors when used alone without proper modifications. 3m-ARMS-based mutation detection is fast and simple with potential for use as a diagnostic test for the majority of hot spot mutations in IDH1/2 genes. It can detect IDH1/2 mutations within an hour so can be adapted for intraoperative diagnosis.

Integrating Ligand and Target-Driven Based Virtual Screening Approaches With in vitro Human Cell Line Models and Time-Resolved Fluorescence Resonance Energy Transfer Assay to Identify Novel Hit Compounds Against BCL-2.

Antiapoptotic members of B-cell leukemia/lymphoma-2 (BCL-2) family proteins are one of the overexpressed proteins in cancer cells that are oncogenic targets. As such, targeting of BCL-2 family proteins raises hopes for new therapeutic discoveries. Thus, we used multistep screening and filtering approaches that combine structure and ligand-based drug design to identify new, effective BCL-2 inhibitors from a small molecule database (Specs SC), which includes more than 210,000 compounds. This database is first filtered based on binary "cancer-QSAR" model constructed with 886 training and 167 test set compounds and common 26 toxicity quantitative structure-activity relationships (QSAR) models. Predicted non-toxic compounds are considered for target-driven studies. Here, we applied two different approaches to filter and select hit compounds for further in vitro biological assays and human cell line experiments. In the first approach, a molecular docking and filtering approach is used to rank compounds based on their docking scores and only a few top-ranked molecules are selected for further long (100-ns) molecular dynamics (MD) simulations and in vitro tests. While docking algorithms are promising in predicting binding poses, they can be less prone to precisely predict ranking of compounds leading to decrease in the success rate of in silico studies. Hence, in the second approach, top-docking poses of each compound filtered through QSAR studies are subjected to initially short (1 ns) MD simulations and their binding energies are calculated via molecular mechanics generalized Born surface area (MM/GBSA) method. Then, the compounds are ranked based on their average MM/GBSA energy values to select hit molecules for further long MD simulations and in vitro studies. Additionally, we have applied text-mining approaches to identify molecules that contain "indol" phrase as many of the approved drugs contain indole and indol derivatives. Around 2700 compounds are filtered based on "cancer-QSAR" model and are then docked into BCL-2. Short MD simulations are performed for the top-docking poses for each compound in complex with BCL-2. The complexes are again ranked based on their MM/GBSA values to select hit molecules for further long MD simulations and in vitro studies. In total, seven molecules are subjected to biological activity tests in various human cancer cell lines as well as Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) assay. Inhibitory concentrations are evaluated, and biological activities and apoptotic potentials are assessed by cell culture studies. Four molecules are found to be limiting the proliferation capacity of cancer cells while increasing the apoptotic cell fractions.

Correlations between genomic subgroup and clinical features in a cohort of more than 3000 meningiomas.

OBJECTIVE: Recent large-cohort sequencing studies have investigated the genomic landscape of meningiomas, identifying somatic coding alterations in NF2, SMARCB1, SMARCE1, TRAF7, KLF4, POLR2A, BAP1, and members of the PI3K and Hedgehog signaling pathways. Initial associations between clinical features and genomic subgroups have been described, including location, grade, and histology. However, further investigation using an expanded collection of samples is needed to confirm previous findings, as well as elucidate relationships not evident in smaller discovery cohorts. METHODS: Targeted sequencing of established meningioma driver genes was performed on a multiinstitution cohort of 3016 meningiomas for classification into mutually exclusive subgroups. Relevant clinical information was collected for all available cases and correlated with genomic subgroup. Nominal variables were analyzed using Fisher's exact tests, while ordinal and continuous variables were assessed using Kruskal-Wallis and 1-way ANOVA tests, respectively. Machine-learning approaches were used to predict genomic subgroup based on noninvasive clinical features. RESULTS: Genomic subgroups were strongly associated with tumor locations, including correlation of HH tumors with midline location, and non-NF2 tumors in anterior skull base regions. NF2 meningiomas were significantly enriched in male patients, while KLF4 and POLR2A mutations were associated with female sex. Among histologies, the results confirmed previously identified relationships, and observed enrichment of microcystic features among "mutation unknown" samples. Additionally, KLF4-mutant meningiomas were associated with larger peritumoral brain edema, while SMARCB1 cases exhibited elevated Ki-67 index. Machine-learning methods revealed that observable, noninvasive patient features were largely predictive of each tumor's underlying driver mutation. CONCLUSIONS: Using a rigorous and comprehensive approach, this study expands previously described correlations between genomic drivers and clinical features, enhancing our understanding of meningioma pathogenesis, and laying further groundwork for the use of targeted therapies. Importantly, the authors found that noninvasive patient variables exhibited a moderate predictive value of underlying genomic subgroup, which could improve with additional training data. With continued development, this framework may enable selection of appropriate precision medications without the need for invasive sampling procedures.

Integration of multi-scale molecular modeling approaches with experiments for the in silico guided design and discovery of novel hERG-Neutral antihypertensive oxazalone and imidazolone derivatives and analysis of their potential restrictive effects on cell proliferation.

AT1 antagonists is the most recent drug class of molecules against hypertension and they mediate their actions through blocking detrimental effects of angiotensin II (A-II) when acts on type I (AT1) A-II receptor. The effects of AT1 antagonists are not limited to cardiovascular diseases. AT1 receptor blockers may be used as potential anti-cancer agents - due to the inhibition of cell proliferation stimulated by A-II. Therefore, AT1 receptors and the A-II biosynthesis mechanisms are targets for the development of new synthetic drugs and therapeutic treatment of various cardiovascular and other diseases. In this work, multi-scale molecular modeling approaches were performed and it is found that oxazolone and imidazolone derivatives reveal similar/better interaction energy profiles compared to the FDA approved sartan molecules at the binding site of the AT1 receptor. In silico-guided designed hit molecules were then synthesized and tested for their binding affinities to human AT1 receptor in radioligand binding studies, using [125I-Sar1-Ile8] AngII. Among the compounds tested, 19d and 9j molecules bound to receptor in a dose response manner and with relatively high affinities. Next, cytotoxicity and wound healing assays were performed for these hit molecules. Since hit molecule 19d led to deceleration of cell motility in all three cell lines (NIH3T3, A549, and H358) tested in this study, this molecule is investigated in further tests. In two cell lines (HUVEC and MCF-7) tested, 19d induced G2/M cell cycle arrest in a concentration dependent manner. Adherent cells detached from the plates and underwent cell death possibly due to apoptosis at 19d concentrations that induced cell cycle arrest.

In vivo effect of pregnancy on angiogenesis potential of arteriovenous malformation tissue samples: an experimental study.

BACKGROUND: Increased angiogenic potential of cerebrovascular malformations during pregnancy may help to explain the complications of arteriovenous malformations (AVMs) in this group of patients. This experimental study investigated the effect of pregnancy on angiogenic activity of implanted AVM tissue samples. METHODS: A subject group of 10 pregnant rats and 10 non-pregnant rats as controls were used. Surgical AVM resection samples were implanted into the micropocket created in both eyes of each animal. Vascular development was assessed by vessel count throughout the study period. In addition, immunohistochemical studies were done for vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF), and their receptors (VEGFR, PDGFR). RESULTS: Statistically significant increase in the number of vessels was found in both groups (P<0.0001); however, the increase in the pregnant group was greater (P=0.0032). The difference between the two groups was evident at the 25th day of the experiment. Despite both groups showed increased level, there was no difference with the level of VEGF, VEGF receptor, PDGF, or PDGF receptor (P>0.05 for all comparisons). CONCLUSIONS: Findings of this study suggest that angiogenic activity of AVM tissues may increase during late pregnancy, hence physicians should inform pregnant patients with AVM of the potential risk.

Knockdown of Pin1 leads to reduced angiogenic potential and tumorigenicity in glioblastoma cells.

Glioblastoma is the most common and most aggressive type of primary brain tumor. Current approaches in the treatment of glioblastoma are not effective enough to increase patient survival or prevent recurrence following surgery. Consequently, the search for potential drug targets is ongoing. Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1), an isomerase that is overexpressed in various tumors, has become an attractive molecule in cancer research. Pin1 has been reported to regulate proteins involved in essential cellular pathways that mediate cell proliferation, cell cycle progression, differentiation and apoptosis, by altering their stability and function. The results of the present study revealed that knockdown of Pin1 in glioblastoma cells using RNA interference or the selective Pin1 inhibitor, juglone, suppressed the tumorigenic features by reducing cell growth, migration and angiogenic potential. Furthermore, knockdown of Pin1 decreased the levels of vascular endothelial growth factor and matrix metallopeptidase 9, and also triggered apoptosis. Due to the fundamental roles of Pin1 in promoting tumorigenesis, Pin1 inhibitory molecules, including juglone, or alternative synthetic derivatives hold potential for the development of clinical countermeasures against glioblastoma.

Gamma knife radiosurgery inhibits angiogenesis of meningiomas: in vivo rat corneal assay.

OBJECTIVE: The aim of this study is to reveal inhibitory effect of gamma knife irradiation on angiogenesis of meningiomas using rat corneal angiogenesis assay. METHODS: A total of 72 rats were divided into three preliminary groups. Each group, consisting of 24 rats, was implanted to World Health Organization (WHO) grade I (typical), grade II (atypical), and grade III (malignant) meningioma. Each of these three preliminary groups of 24 rats, were then divided into four subgroups, each consisting of 6 rats and subsequently irradiated by gamma knife with dose prescriptions of 0, 14, 18, and 22 Gy. The numbers of vessels that developed around the micropockets of the corneas were counted and photographed on days 5, 10, 15, and 20. RESULTS: For WHO grade I meningiomas, 18 and 22 Gy doses (P < 0.001), and for grade II meningiomas, the 22-Gy (P = 0.021) dose were found to inhibit tumor-induced angiogenesis compared with the radiation-free control group. For grade III meningiomas, there was no statistical difference with the control group in any of the doses applied. Our findings demonstrate that gamma knife irradiation may suppress the angiogenic activity of WHO grades I and II meningiomas but not of the grade III meningiomas. CONCLUSIONS: For the first time, this study provides an experimental data to show the antiangiogenic effect of gamma knife irradiation on meningiomas.