Project description:We found constitutive upregulation and higher degree induction of drug metabolism and disposition-related genes in a three-dimensional HepG2 culture. The upregulated genes are those believed to be regulated by different regulatory factors. The global gene expression analysis by Affymetrix GeneChip indicated that altered expressions of microtubule-related genes may change expressed levels of drug metabolism and disposition genes. Stabilization of the microtubule molecules with docetaxel, a tubulin stabilizing agent, in the two-dimensional culture showed gene expression patterns similar to those in the three-dimensional culture, indicating that culture environment affects drug metabolism functions in HepG2 cells. Keywords: radial flow bioreactor cell culture system, three dimensional culture, HepG2, GeneChip U133A,
Project description:We found constitutive upregulation and higher degree induction of drug metabolism and disposition-related genes in a three-dimensional HepG2 culture. The upregulated genes are those believed to be regulated by different regulatory factors. The global gene expression analysis by Affymetrix GeneChip indicated that altered expressions of microtubule-related genes may change expressed levels of drug metabolism and disposition genes. Stabilization of the microtubule molecules with docetaxel, a tubulin stabilizing agent, in the two-dimensional culture showed gene expression patterns similar to those in the three-dimensional culture, indicating that culture environment affects drug metabolism functions in HepG2 cells. Experiment Overall Design: We compared the gene expression data from HepG2 cells cultured in the radial flow bioreactor (RFB) cell culture system for six days to those from HepG2 cells cultured in tissue culture plates for five days. Both cell cultures (RFB culture and plate culture) were performed twice independently. In each culture, three samples were collected from three different portions of the bioreactor or from three different tissue culture plates. Microarray analyses were performed in duplicate for each sample using the Affymetrix human genome U133A GeneChip.
Project description:The development of more complex but reliable systems for compound testing in a pharmaceutical context is a challenging task to date. Three-dimensional (3D), organ mimetic cell culture is aiming to become an alternative to common two-dimensional (2D) cell culture or animal testing in that field. We developed a biocompatible 3D cell culture environment for a hepatocellular carcinoma (HCC) model that enables cellular maintenance in a polycarbonate scaffold structure. Albumin, regarded as a differentiation marker, was elevated in statically 3D cultivated HepG2 cells. Expression of HCC tumor marker alpha-fetoprotein (AFP) was reduced compared to immunofluorescence stainings of 2D cultivated cells. Remarkably, expression of cytokeratin and pathophysiologically relevant beta-1 integrin (ITGB1) was found enhanced in nonperfused 3D cell culture. Changes in gene expression induced by the 3D cultivation environment were investigated using Ingenuity Pathway Analysis (IPA). Our findings revealed involvement of the insulin growth factor (IGF) signaling pathway in upregulation of matrix metalloproteinases (MMP) and ITGB1. The experimental data indicate a more differentiated state in 3D cultivated HepG2 cells than in the respective 2D experiments. Hence, scaffold-supported 3D cultivation of HepG2 cells may lead to a gain of information valuable for both drug testing and cancer research. HepG2 cells were cultivated for five days under 2D and 3D statical and perfused conditions. Cultivation was started with 0.25x10^6 cells in 2D and with 1x10^6 vital cells for the 3D experiments. The day of seeding was defined as d0. The groups were classified as follows: 2D, i.e., monolayer cultures, 3D, i.e., statical 3D cultures and BR, which denotes perfused 3D culture of HepG2 cells. The perfusable bioreactor system was operated using a peristaltic pump. It houses the MatriGrid, a polycarbonate-based microporous cellular support. For 3D static cultivation, cell-inoculated MatriGrids were placed in wells of a 24-well plate. Microarray experiments of three 2D (i.e., control), three 3D statically and three actively perfused 3D cultivations were performed at SIRS-Lab GmbH (SIRS-Lab GmbH, Jena, Germany) according to the manufacturer's instructions (Illumina, San Diego, CA). Altogether, 9 RNA samples of hepatocyte cultures and an internal control RNA were hybridized on two HumanHT-12 v4 Expression BeadChips.
Project description:The development of more complex but reliable systems for compound testing in a pharmaceutical context is a challenging task to date. Three-dimensional (3D), organ mimetic cell culture is aiming to become an alternative to common two-dimensional (2D) cell culture or animal testing in that field. We developed a biocompatible 3D cell culture environment for a hepatocellular carcinoma (HCC) model that enables cellular maintenance in a polycarbonate scaffold structure. Albumin, regarded as a differentiation marker, was elevated in statically 3D cultivated HepG2 cells. Expression of HCC tumor marker alpha-fetoprotein (AFP) was reduced compared to immunofluorescence stainings of 2D cultivated cells. Remarkably, expression of cytokeratin and pathophysiologically relevant beta-1 integrin (ITGB1) was found enhanced in nonperfused 3D cell culture. Changes in gene expression induced by the 3D cultivation environment were investigated using Ingenuity Pathway Analysis (IPA). Our findings revealed involvement of the insulin growth factor (IGF) signaling pathway in upregulation of matrix metalloproteinases (MMP) and ITGB1. The experimental data indicate a more differentiated state in 3D cultivated HepG2 cells than in the respective 2D experiments. Hence, scaffold-supported 3D cultivation of HepG2 cells may lead to a gain of information valuable for both drug testing and cancer research.
Project description:Primary human hepatocytes (PHH) are a main instrument in drug metabolism research and in the prediction of drug-induced phase I/II enzyme induction in humans. The HepG2 liver-derived cell line is commonly used as a surrogate for human hepatocytes, but their use in ADME and toxicity studies can be limited because of lowered basal levels of metabolizing enzymes. Despite their widespread use, the transcriptome of HepG2 cells compared to PHH is not well characterized. In this study, microarray analysis was conducted to ascertain the differences and similarities in mRNA expression between HepG2 cells and human hepatocytes before and after exposure to a panel of fluoroquinolone compounds. Comparison of the naïve HepG2 cell and PHH transcriptomes revealed a substantial number of basal gene expression differences. When HepG2 cells were dosed with a series of fluoroquinolones, trovafloxacin, which has been associated with human idiosyncratic hepatotoxicity, induced substantially more gene expression changes than the other quinolones, similar to previous observations with PHH. While TVX-treatment resulted in many gene expression differences between HepG2 cells and PHH, there were also a number of TVX-induced commonalities, including genes involved in RNA processing and mitochondrial function. Taken together, these results provide insight for interpretation of results from drug metabolism and toxicity studies conducted with HepG2 cells in lieu of PHH, and could provide further insight into the mechanistic evaluation of TVX-induced hepatotoxicity. Experiment Overall Design: HepG2 cells were obtained from the American Type Culture Collection (Rockville, MD). The cells were cultured in Minimum Essential Medium (Invitrogen Life Technologies, Carlsbad,CA) with 10% Fetal Bovine Serum under a humidified 5% CO2 atmosphere using T-162 plastic culture flasks. The cells were split when they reached approximately 70-85% confluence after washing with sterile phosphate buffered saline and detachment of the cells with trypsin (Invitrogen Life Technologies, Carlsbad, CA). The HepG2 cells were cultured in 6-well plastic plates upon exposure to quinolone compounds. Primary human hepatocytes, obtained from In Vitro Technologies (IVT, Baltimore, MD) in 6-well type I collagen coated plates, were cultured with 2 mL of Hepatocyte Incubation Media (IVT) at 37°C with 5% CO2 for 24 hours after receipt. Experiment Overall Design: For the genomic experiments, quinolone compounds, dissolved in 0.1 N KOH (Sigma Chemical Co., St. Louis, MO), were added to the wells with fresh media at levels of 100 µM (HepG2) or 400 µM (primary human hepatocytes) for 24 hours using at least two technical replicates. Trovafloxacin was dosed using two separate preparations of HepG2 cells and two separate donors of human hepatocytes. Vehicle control cells were dosed with an equivalent volume of 0.1N KOH as the experimental samples. For intracellular comparison (HepG2 cells vs PHH), naïve cells were harvested using TRIzol� reagent (Invitrogen Life Technologies, Carlsbad, CA). Experiment Overall Design: Total RNA was isolated from the TRIzol� extracts using the standard procedure from the manufacturer. O.D. at 260 nm determined RNA concentrations. RNA quality was accessed using an Agilent Technologies bioanalyzer before proceeding to microarray sample preparation. Microarray analysis was performed using the standard protocol provided by Affymetrix Inc. (Santa Clara, CA) and as previously described, starting with 5 µg of total RNA (Richert et al., 2006). Experiment Overall Design: Fragmented, labeled cRNA was hybridized to an Affymetrix human genome U133A array, which contains sequences corresponding to roughly 22,200 transcripts at 45°C overnight. The arrays were washed, developed, and scanned.
Project description:Investigation of whole genome gene expression level changes in hepatocellular carcinoma cell line hepG2 in regular culture, hepG2-slug in regular culture and hepG2-slug on Matrigel. Whole genome gene expression level changes have been compared in hepatocellular carcinoma cell line hepG2 in regular culture, hepG2-slug in regular culture and hepG2-slug on Matrigel. Roche NimbleGen micro-array analysis was employed to assess global genome expression in HepG2 in regular culture, HepG2-slug in regular culture and HepG2-slug on Matrigel. The results demonstrated that the up-regulated genes and the down-regulated genes increased significantly when HepG2-slug cells with VM forming ablity were cultured on Matrigel and formed VM.
Project description:Preclinical cancer drug discovery efforts have employed two-dimensional (2D)-cell-based assay models, which fail to forecast in vivo efficacy and contribute to a lower success rates of clinical approval. Three-dimensional (3D) cell culture models are recently expected to bridge the gap between 2D and in vivo models. We have developed novel 3D culture method that improves the growth of spheroid-forming cancer cells under anchorage-independent condition by leveraging a feature of FP001. Gene microarrays were used to observe the global gene expression in A549 cells cultured in multi-well plate with or without FP001 and identified distinct classes of up or down-regulated genes.
Project description:Primary human hepatocytes (PHH) are a main instrument in drug metabolism research and in the prediction of drug-induced phase I/II enzyme induction in humans. The HepG2 liver-derived cell line is commonly used as a surrogate for human hepatocytes, but their use in ADME and toxicity studies can be limited because of lowered basal levels of metabolizing enzymes. Despite their widespread use, the transcriptome of HepG2 cells compared to PHH is not well characterized. In this study, microarray analysis was conducted to ascertain the differences and similarities in mRNA expression between HepG2 cells and human hepatocytes before and after exposure to a panel of fluoroquinolone compounds. Comparison of the naïve HepG2 cell and PHH transcriptomes revealed a substantial number of basal gene expression differences. When HepG2 cells were dosed with a series of fluoroquinolones, trovafloxacin, which has been associated with human idiosyncratic hepatotoxicity, induced substantially more gene expression changes than the other quinolones, similar to previous observations with PHH. While TVX-treatment resulted in many gene expression differences between HepG2 cells and PHH, there were also a number of TVX-induced commonalities, including genes involved in RNA processing and mitochondrial function. Taken together, these results provide insight for interpretation of results from drug metabolism and toxicity studies conducted with HepG2 cells in lieu of PHH, and could provide further insight into the mechanistic evaluation of TVX-induced hepatotoxicity. Keywords: Cell Type Comparison
Project description:Around 95% of anti-cancer drugs that show promise during preclinical study fail to gain FDA-approval for clinical use. This failure of the preclinical pipeline highlights the need for improved, physiologically-relevant in vitro models that can better serve as reliable drug-screening and disease modeling tools. The vascularized micro-tumor (VMT) is a novel three-dimensional model system (tumor-on-a-chip) that recapitulates the complex human tumor microenvironment, including perfused vasculature, within a transparent microfluidic device, allowing real-time study of drug responses and tumor–stromal interactions. Here we have validated this microphysiological system (MPS) platform for the study of colorectal cancer (CRC), the second leading cause of cancer-related deaths, by showing that gene expression, tumor heterogeneity, and treatment responses in the VMT more closely model CRC tumor clinicopathology than current standard drug screening modalities, including 2-dimensional monolayer culture and 3-dimensional spheroids.
Project description:Preclinical cancer drug discovery efforts have employed two-dimensional (2D)-cell-based assay models, which fail to forecast in vivo efficacy and contribute to a lower success rates of clinical approval. Three-dimensional (3D) cell culture models are recently expected to bridge the gap between 2D and in vivo models. We have developed a novel 3D culture method that improves the growth of spheroid-forming cancer cells under anchorage-independent condition by leveraging a feature of FP001, a bacteria-derived polysaccharide. Gene microarrays were used to observe the global gene expression in SKOV3 cells cultured with adhesion condition (2D, control) or with low adhesion condition (FP001) and identified distinct classes of up or down-regulated genes.