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ABSTRACT: Novel tetrahydroisoquinoline (THI) analogs were designed, synthesized, and their antiglioma activity was evaluated. The results
showed that 6,8-dimethoxy-1-(2′-methoxybiphenyl-4-ylmethyl)-1,2,3,4-tetrahydroisoquinoline hydrochloride (25) demonstrated improved potency, and selectivity on C6 rat glioma vs cultured rat astrocytes (EC50 0.63μM vs. 10.85μM) compared to our recent lead molecule EDL-155 (EC50 1.5μM vs. 27.4μM). The isomers of 25 were isolated using a semi-preparative high-performance liquid chromatography (HPLC) method, and their in vitro biological
evaluation revealed that (+) 25 was the most active, and it was nearly 21 fold more potent than (−) 25, suggesting the antiglioma profile is influenced by stereochemical factors.
KeywordsGlioblastoma multiforme (GBM)–Tetrahydroisoquinoline (THI)–Isomers–EDL-155–Antiglioma activity
Medicinal Chemistry Research 04/2012; 20(1):131-137. · 1.27 Impact Factor
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ABSTRACT: To investigate the effectiveness of EDL-291, a 6,7-dimethoxy-1-[4-(4-methoxypyridin-3-yl)benzyl]-1,2,3,4-tetrahydroisoquinoline dihydrochloride compound, in inhibiting the survival of glioblastoma in vitro and in vivo. Dose-response curves were generated to determine the EC50 in rat and human glioblastoma cell lines by treatment with different dilutions of EDL-291. To evaluate the architecture of the glioblastoma cells after treatment with EDL-291, the rat and human glioblastoma cells were stained with Mito Tracker Green FM. To determine whether autophagy was induced in EDL-291-treated glioblastoma cells, both rat and human glioblastoma cell lines were stained with acridine orange and light chain-3 immunoblots were performed. The efficacy of EDL-291 was monitored in vivo using a rat glioblastoma model. Rat glioblastoma cells were transplanted into an intracranial rat model, followed by infusions of saline, a low dose of EDL-291 (20 mg/kg for the first half hour, followed by 40 mg/kg EDL-291 in saline for 4 h), or a high dose of EDL-291 (60 mg/kg for the first half hour, followed by 90 mg/kg EDL-291 for 4 h). EDL-291 inhibits glioblastoma in vitro by destroying the mitochondria as shown with Mito Tracker Green FM. Acridine orange staining and light chain-3 immunoblots suggest that autophagy is induced when glioblastoma cells are treated with EDL-291. In vivo, a low dosage of EDL-291 is sufficient and effective in reducing glioblastoma tumor size. EDL-291 selectively induces cell death in rat and human glioblastoma cell lines by the induction of autophagy. EDL-291 exhibits antiglioblastoma effects both in vitro and in vivo.
Anti-cancer drugs 03/2012; 23(5):494-504. · 2.23 Impact Factor
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ABSTRACT: The present study examines the structure and covariance of endogenous variation in gene expression across the recently expanded family of C57BL/6J (B) X DBA/2J (D) Recombinant Inbred (BXD RI) strains of mice. This work is accompanied by a highly interactive database that can be used to generate and test specific hypotheses. For example, we define the genetic network regulating growth associated protein 43 (Gap43) and phosphatase tensin homolog (Pten).
The Hamilton Eye Institute (HEI) Retina Database within GeneNetwork features the data analysis of 346 Illumina Sentrix BeadChip Arrays (mouse whole genome-6 version 2). Eighty strains of mice are presented, including 75 BXD RI strains, the parental strains (C57BL/6J and DBA/2J), the reciprocal crosses, and the BALB/cByJ mice. Independent biologic samples for at least two animals from each gender were obtained with a narrow age range (48 to 118 days). Total RNA was prepared followed by the production of biotinylated cRNAs, which were pipetted into the Mouse WG-6V2 arrays. The data was globally normalized with rank invariant and stabilization (2z+8).
The HEI Retina Database is located on the GeneNetwork website. The database was used to extract unique transcriptome signatures for specific cell types in the retina (retinal pigment epithelial, amacrine, and retinal ganglion cells). Two genes associated with axonal outgrowth (Gap43 and Pten) were used to display the power of this new retina database. Bioinformatic tools located within GeneNetwork in conjunction with the HEI Retina Database were used to identify the unique signature Quantitative Trait Loci (QTLs) for Gap43 and Pten on chromosomes 1, 2, 12, 15, 16, and 19. Gap43 and Pten possess networks that are similar to ganglion cell networks that may be associated with axonal growth in the mouse retina. This network involves high correlations of transcription factors (SRY sex determining region Y-box 2 [Sox2], paired box gene 6 [Pax6], and neurogenic differentiation 1 [Neurod1]), and genes involved in DNA binding (proliferating cell nuclear antigen [Pcna] and zinc finger, BED-type containing 4 [Zbed4]), as well as an inhibitor of DNA binding (inhibitor of DNA binding 2, dominant negative helix-loop-helix protein [Id2]). Furthermore, we identified the potential upstream modifiers on chromosome 2 (teashirt zinc finger homeobox 2 [Tshz2], RNA export 1 homolog [Rae1] and basic helix-loop-helix domain contatining, class B4 [Bhlhb4]) on chromosome 15 (RAB, member of RAS oncogene family-like 2a [Rabl2a], phosphomannomutase 1 [Pmm1], copine VIII [Cpne8], and fibulin 1 [Fbln1]).
The endogenous variation in mRNA levels among BXD RI strains can be used to explore and test expression networks underlying variation in retina structure, function, and disease susceptibility. The Gap43 and Pten network highlights the covariance of gene expression and forms a molecular network associated with axonal outgrowth in the adult retina.
Molecular vision 01/2011; 17:1355-72. · 2.20 Impact Factor
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ABSTRACT: The present study examines the effects of Cd81-null mutation on the development of the retinal pigment epithelium (RPE), specifically cell size and number of cells with multiple nuclei. The outlines of RPE in retinal flat mounts were stained with rhodamine-labeled phalloidin and RPE nuclei with Hoechst stain. The RPE layer was sampled to define the number of cells, the size of the RPE cells and the number of nuclei within the cells. The Cd81-null mutation caused an increase in the number of cells within the RPE layer. The cells were smaller than those in the wild type mice. Furthermore there was an increase in the number of mono-nucleated cells. In the posterior portion of the eye there was a significant increase in the number of multi-nucleated cells. The data indicate that CD81 plays a significant role in the final stages of RPE development, controlling cell number and overall developmental pattern.
Neurochemical Research 09/2010; 36(4):569-73. · 2.24 Impact Factor
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ABSTRACT: Müller cells serve many functions including the regulation of extracellular glutamate levels. The product of two genes, Slc1a3 [aka solute carrier family 1 (glial high affinity glutamate transporter), member 3] and Glul (aka glutamine synthetase) are the primary role players that transport glutamate into the Müller cell and convert it into glutamine. In this study, we sought to identify the genetic regulation of both genes. Given their tightly coupled biological functions, we predicted that they would be similarly regulated. Using an array of 75 recombinant inbred strains of mice, we determined that Slc1a3 and Glul are differentially regulated by distinct chromosomal regions. Interestingly, despite their independent regulation, gene ontology analysis of tightly correlated genes reveals that the enriched and statistically significant molecular function categories of both directed acyclic graphs have substantial overlap, indicating that the shared functions of correlates of Slc1a3 and Glul include production and usage of ATP.
Neurochemical Research 09/2010; 36(4):594-603. · 2.24 Impact Factor
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ABSTRACT: The effects of 1-(biphenyl-4-ylmethyl)-1,2,3,4-tetrahydroisoquinoline-6,7-diol (EDL-155) on the growth of glioma was tested in vitro and in vivo. Normal cultured rat astrocytes and C6 rat glioma were used as a differential screen to test the effects of EDL-155. The compound was preferentially cytotoxic for C6 glioma (EC50=1.5 micromol/l) relative to cultured neonatal astrocytes (EC50=27.4 micromol/l). When compared with a standard chemotherapeutic agent, carmustine (1,3-bis[2-chloroethyl]-1-nitrosourea), or temozolomide, EDL-155 was more selective and more potent in our differential tissue culture assay. The effect of EDL-155 was also tested in an animal model in which C6 glioma was transplanted into the brains of Sprague-Dawley rats. EDL-155 was delivered directly onto the tumor by an osmotic minipump directly into the brain or by intraperitoneal injection. Animals treated with EDL-155 had significantly smaller tumors than did control animals treated with carrier solution. We observed anatomical changes in cultured glioma cells treated with EDL-155 that were consistent with selective destruction of mitochondria and the induction of autophagy. These changes were not observed in normal astrocytes cultured from rat pups. The selective killing of glioma in tissue culture and in the rat brain models indicates that EDL-155 has potential therapeutic value in treating this type of brain cancer.
Anti-Cancer Drugs 11/2008; 19(9):859-70. · 2.41 Impact Factor
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ABSTRACT: Tetrahydroisoquinolines (THIs) have demonstrated anti-cancer activity in rodent models of glioma, a form of brain cancer refractory to therapeutic intervention. In this study, peripheral and cerebrospinal fluid (CSF) pharmacokinetics in rats were determined to assess the drug developability of the novel THI EDL-155 for the treatment of glioma.
Serial blood and CSF samples were collected from rats following intravenous bolus administration of EDL-155 (10-20 mg/kg). Samples were analyzed by LC/MS/MS. Pharmacokinetic analyses using compartmental and noncompartmental methods were performed using the computer program WinNonlin. Plasma protein binding was measured using the charcoal adsorption method. The in vivo efficacy of EDL-155 (i.p. 20 mg/kg twice daily for 7 days) was assessed in rats with stereotactically implanted C6 glioma cells into the caudate.
EDL-155 plasma concentration data were described by a one-compartment model. EDL-155 demonstrated rapid clearance (342.5+/-49.9 ml/min/kg), high volume of distribution (13.0+/-1.2 l/kg) and a terminal half-life of 23.7+/-1.5 min. Dose-normalized CSF area under the curve (AUC(CSF)) as a percentage of peripheral exposure (AUC(Plasma)) was 1.4%. EDL-155 was highly bound to plasma proteins (>93%). Intracranial tumor volume at 7 days post-implantation was approximately 30% smaller in animals treated with EDL-155 when compared to vehicle control animals (13.2+/-5.3 mm(3) vs. 18.7+/-6.3 mm(3); P=0.04).
High clearance and extensive protein binding limit the brain availability of EDL-155 following systemic administration. EDL-155 treatment resulted in reduced tumor size despite limited blood brain barrier penetrability, which suggests that analogs with increased metabolic stability and brain penetrability may provide a therapeutic option for primary central nervous system tumors such as glioma. On-going studies are focused on the design, synthesis, and testing of novel analogs based upon these findings.
Cancer Chemotherapy and Pharmacology 06/2008; 61(6):1037-44. · 2.83 Impact Factor
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ABSTRACT: Retinal pigment epithelium cells play an important role in the pathogenesis of age related macular degeneration. Their morphological, molecular and functional phenotype changes in response to various stresses. Functional profiling of genes can provide useful information about the physiological state of cells and how this state changes in response to disease or treatment. In this study, we have constructed a functional profile of the genes expressed by the ARPE-19 cell line of retinal pigment epithelium.
Using Affymetrix MAS 5.0 microarray analysis, genes expressed by ARPE-19 cells were identified. Using GeneChip annotations, these genes were classified according to their known functions to generate a functional gene expression profile.
We have determined that of approximately 19,044 unique gene sequences represented on the HG-U133A GeneChip, 6,438 were expressed in ARPE-19 cells irrespective of the substrate on which they were grown (plastic, fibronectin, collagen, or Matrigel). Rather than focus our subsequent analysis on the identity or level of expression of each individual gene in this large data set, we examined the number of genes expressed within 130 functional categories. These categories were selected from a library of HG-U133A GeneChip annotations linked to the Affymetrix MAS 5.0 data sets. Using this functional classification scheme, we were able to categorize about 70% of the expressed genes and condense the original data set of over 6,000 data points into a format with 130 data points. The resulting ARPE-19 Functional Gene Expression Profile is displayed as a percentage of ARPE-19-expressed genes.
The Profile can readily be compared with equivalent microarray data from other appropriate samples in order to highlight cell-specific attributes or treatment-induced changes in gene expression. The usefulness of these analyses is based on the assumption that the numbers of genes expressed within a functional category provide an indicator of the overall level of activity within that particular functional pathway.
BMC Ophthalmology 02/2005; 5:25. · 1.00 Impact Factor
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ABSTRACT: The present study was designed to compare the results obtained from two different microarray platforms: spotted cDNAs using a two-color system (Clontech, Atlas Glass Human 3.8) and the Affymetrix platform. We evaluated the internal consistency within each of the platforms, and compared the results across the two platforms.
RNA was isolated from two retinal pigment epithelial (RPE) cell lines, D407 cells and ARPE19 cells. Each microarray system requires a specific RNA isolation and target preparation procedure. To compare the results between the two platforms, the intensity values for each platform were standardized and scaled. This allowed for a direct comparison of the data between two very different microarray platforms. Real-time RT-PCR was used as an independent conformation of expression levels for selected transcripts. The protein levels for some of these genes were determined using a quantitative immunoblot method.
First, we compared the transcriptome of the D407 cell line to itself. Within each of the platforms there was a high degree of consistency. However, when the data from the Atlas Glass Human 3.8 microarray platform was compared to that of the Affymetrix platform there was a dramatic lack of agreement. The second step was to compare the mRNA profile of the ARPE19 cell line to the D407 cell line. Again there was good agreement within each platform. When the results of the Atlas Glass Human 3.8 platform were compared to the Affymetrix platform, there was a surprising lack of agreement between the two data sets. Real-time RT-PCR was used as independent means of defining RNA levels in the two cell lines. In general, the real-time RT-PCR results were in better agreement with the Affymetrix platform (85%) than the Atlas Glass platform (33%). In addition, we also examined the levels of 11 proteins in these two cell lines using a quantitative immunoblot method. The results from this protein analysis had a higher degree of concordance with the results from Affymetrix platform.
In both the Atlas Glass Human 3.8 system and the Affymetrix platform, there is a high degree of internal consistency. However, comparisons between the two platforms show a lack of agreement. In general, the real-time RT-PCR confirmed the results on the Affymetrix system more often than those from Atlas Glass arrays. However, in both cases, conformation by an independent method proves to be of considerable value.
Molecular vision 11/2003; 9:482-96. · 2.20 Impact Factor
