Discovery of a drug targeting microenvironmental support for lymphoma cells by screening using patient-derived xenograft cells
ABSTRACT: Cell lines have been used for drug discovery as useful models of cancers; however, they do not recapitulate cancers faithfully, especially in the points of rapid growth rate and microenvironment independency. Consequently, the majority of conventional anti-cancer drugs are less sensitive to slow growing cells and do not target microenvironmental support, although most primary cancer cells grow slower than cell lines and depend on microenvironmental support. Here, we developed a novel high throughput drug screening system using patient-derived xenograft (PDX) cells of lymphoma that maintained primary cancer cell phenotype more than cell lines. The library containing 2613 known pharmacologically active substance and off-patent drugs were screened by this system. We could find many compounds showing higher cytotoxicity than conventional anti-tumor drugs. Especially, pyruvinium pamoate showed the highest activity, and its strong anti-tumor effect was confirmed also in vivo. We extensively investigated its mechanism of action and found that it inhibited glutathione supply from stromal cells to lymphoma cells, implying the importance of the stromal protection from ox 1 idative stress for lymphoma cell survival and a new therapeutic strategy for lymphoma. Our system introduces a primary cancer cell phenotype into cell-based phenotype screening and sheds new light on anti-cancer drug development. Global gene expression profiles of PDX cells showed high similarity to those of original primary cells. The correlation coefficient of gene expression profiles between PDX cells and the originalprimary cells was 0.814-0.890.
Project description:Post-lactational involution of the mammary gland provides a unique model to study breast cancer susceptibility and metastasis. We have shown that the short isoform of Singleminded-2 (Sim2s), a bHLH/PAS transcription factor, plays a role in promoting lactogenic differentiation, as well as in maintaining mammary epithelial differentiation and malignancy. Sim2s is dynamically expressed during mammary gland development, with expression peaking during lactation, and decreasing in early involution. To determine the role of Sim2s in involution, we used transgenic mice expressing Sim2s under the mouse mammary tumor virus (MMTV-Sim2s) promoter. Over-expression of Sim2s in the mouse mammary gland resulted in delayed involution, indicated by a lower proportion of cleaved caspase-3 positive cells and slower re-establishment of the mammary fat pad. Immunohistochemical and quantitative RNA analysis showed a decrease in apoptotic markers and inflammatory response genes, and an increase in anti-apoptotic genes, which were accompanied by inhibition of signal transducer and activator of transcription 3 (Stat3) activity. Microarray analysis confirmed that genes in the Stat3 signaling pathway were repressed by Sim2s expression, along with NFκB and other key pathways involved in mammary gland development. Multiparous MMTV-Sim2s females displayed a more differentiated phenotype compared to wild-type controls, characterized by enhanced β-casein expression and alveolar structures. Together, these results suggest a role for Sim2s in the normal involuting gland, and identify potential down-stream pathways regulated by Sim2s. Gene expression was measured in 6 mammary gland samples using CodeLink Mouse Whole Genome microarrays. 3 samples were from wild-type mice harvested at 72 hours post weaning and 3 samples were MMTV-Sim2s mice harvested at 72 hours post weaning.
Project description:Cell lines have been used for drug discovery as useful models of cancers; however, they do not recapitulate cancers faithfully, especially in the points of rapid growth rate and microenvironment independency. Consequently, the majority of conventional anti-cancer drugs are less sensitive to slow growing cells and do not target microenvironmental support, although most primary cancer cells grow slower than cell lines and depend on microenvironmental support. Here, we developed a novel high throughput drug screening system using patient-derived xenograft (PDX) cells of lymphoma that maintained primary cancer cell phenotype more than cell lines. The library containing 2613 known pharmacologically active substance and off-patent drugs were screened by this system. We could find many compounds showing higher cytotoxicity than conventional anti-tumor drugs. Especially, pyruvinium pamoate showed the highest activity and its strong anti-tumor effect was confirmed also in vivo. We extensively investigated its mechanism of action and found that it inhibited glutathione supply from stromal cells to lymphoma cells, implying the importance of the stromal protection from oxidative stress for lymphoma cell survival and a new therapeutic strategy for lymphoma. Our system introduces a primary cancer cell phenotype into cell-based phenotype screening and sheds new light on anti-cancer drug development.
Project description:Cell lines have been used for drug discovery as useful models of cancers; however, they do not recapitulate cancers faithfully, particularly from the viewpoints of microenvironmental independence. Patient-derived xenografts (PDX) are established by the transfer of primary tumor cells directly from patients into immunodeficient mice and can provide primary-like tumor cells of the amount needed at the desired time. We developed a high-throughput drug screening system using PDX cells and performed drug screening using the PDX cells of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). We established four Ph+ ALL PDX mice and performed high-throughput screening of 3440 compounds using leukemia cells from the PDX mice (PDX-cell screening). The profiles of drugs selected by PDX-cell screening were markedly different from those by screening using the Ph+ ALL cell line. We found that verteporfin, an FDA-approved drug, exhibited strong PDX cell-specific cytotoxicity. In the validation assay, its GI50 was 228 nM, 395 nM, and 538 nM in three PDX cells and 3.93 µM, 2.11 µM, and 5.61 µM in three cell lines. Although verteporfin is a photosensitizer activated by photoirradiation, its cytotoxic effects were mediated by the light-independent production of reactive oxygen species; therefore, its anti-leukemic effects were also exerted in vivo without photoirradiation. Furthermore, it exhibited synergistic effects with dasatinib, an ABL kinase inhibitor. These results indicated the potential of verteporfin as a new anti-leukemic reagent.
Project description:Pemphigus foliaceus (PF) is a complex autoimmune disease characterized by bullous skin lesions and the presence of antibodies against desmoglein 1. In this study we sought to contribute to a better understanding of the molecular processes in endemic PF, since the identification of factors that participate in the pathogenesis is a prerequisite for understanding its biological basis and may lead to novel therapeutic interventions. CD4+ T lymphocytes are central to the development of the disease. Therefore, we compared genome-wide gene expression profiles of peripheral CD4+ T cells of various PF patient subgroups with each other and with that of healthy individuals. The patients sample was subdivided in three groups: untreated patients with the generalized form of the disease, patients submitted to immunosuppressive treatment, and patients with the localized form of the disease. Comparisons between different subgroups resulted in 135, 54 and 64 genes differentially expressed. These genes are mainly related with lymphocyte adhesion and migration, apoptosis, cellular proliferation, cytotoxicity and antigen presentation. Several of these genes were differentially expressed when comparing lesional and uninvolved skin from the same patient. The chromosomal regions 19q31 and 12p13 concentrate differentially expressed genes and are candidate regions for PF susceptibility genes and disease markers. Our results reveal genes involved in severity, potential therapeutic targets and previously unsuspected processes involved in the pathogenesis. Besides, this study adds original information that will contribute to the understanding of PF’s pathogenesis and of the still poorly defined in vivo functions of most of these genes. 24 samples were analyzed, no replicates. Three groups of patients were analyzed: (1) patients with the generalized form of the disease and without treatment; (2) patients with the generalized form undergoing immunosuppressive therapy (prednisone); and (3) patients with the localized form of the disease and without treatment. A fourth group consisted of healthy control subjects.
Project description:In the present study, we aimed to determine the genes involved in inflammatory process of diabetic nephropathy. ICAM-1+/+ and ICAM-1-/- mice aged 8 weeks were divided into four groups: 1) nondiabetic ICAM-1+/+ mice (ND-WT), 2) nondiabetic ICAM-1-/- mice (ND-KO), 3) streptozotocin (STZ)-induced diabetic ICAM-1+/+ mice (DM-WT), and 4) STZ-induced diabetic ICAM-1-/- mice (DM-KO). Three months after the induction of diabetes, total RNA was extracted from each specimen of renal cortex. We examined gene expression profiles of four groups. We identified 193 genes; the ratio of expression level of DM-WT was >2 or <0.5 of that of DM-KO. Of 193 genes, hierarchical clustering identified 33 genes that were significantly upregulated only in DM-WT but not remarkable in ND-WT and ND-KO. Functional annotation of these 33 genes revealed that the significant functions of them were related to the immune or inflammatory process: immune response, response to stimulus, defense response, immune effector process and antigen processing and presentation. These genes contained several inflammatory related genes, such as chemokine (C-X-C motif) ligand 10, chemokine (c-c motif) ligand 12, and chemokine (c-c motif) ligand 8. In this cluster, we focused on cholecystokinin (CCK) because CCK is one of the most up-regulated genes. Real-time RT-PCR revealed that CCK mRNA expression was significantly up-regulated in DM-WT compared with DM-KO. These results suggest that CCK may play a critical role in the progression of diabetic nephropathy by controlling inflammation in diabetic kidney. Male ICAM-1-/- mice (C57BL/6J background) were purchased from The Jackson Laboratory (Bar Harbor, ME). Male C57BL/6J mice (ICAM-1+/+) mice were used as controls. ICAM-1+/+ and ICAM-1-/- mice aged 8 weeks were divided into four groups (n = 5 each): 1) nondiabetic ICAM-1+/+ mice (ND-WT), 2) nondiabetic ICAM-1-/- mice (ND-KO), 3) streptozotocin (STZ)-induced diabetic ICAM-1+/+ mice (DM-WT), and 4) STZ-induced diabetic ICAM-1-/- mice (DM-KO). Mice in the diabetic groups received an intraperitoneal injection of STZ (Sigma Chemical, St.Louis, MO) at 200 mg/kg in citrate buffer (pH 4.5). Blood glucose levels were determined 7 days after STZ injection and only mice with blood glucose concentrations >16 mmol/L were used in the study. Nondiabetic ICAM-1+/+ and ICAM-1-/- mice received citrate buffer injections only. All mice had free access to standard diet and tap water. All animal procedures were performed according to the Guidelines for Animal Experiments at Okayama University Medical School, Japanese Government Animal Protection and Management Law (no. 105), and Japanese Government Notification on Feeding and Safekeeping of Animals (no. 6). Three months after the induction of diabetes, all mice were killed, and the kidneys were harvested. Total RNA was extracted from each specimen of renal cortex using standard protocol from RNeasy midi kit (Qiagen, Valencia, CA) at 3 months. The concentration and the quality of the total RNA sample were assessed by Agilent Bioanalyzer. Biotin-labeled target cRNA was prepared using First and Second strand cDNA Synthesis Kit (Amersham Biosciences, No. 320000) and In Vitro Transcription Kit (Amersham Biosciences, No.320001). Incubate total RNA (5 μg), diluted bacterial mRNA spike controls and T7 oligo (dT) primer for 10 min at 70 C. Add first-strand reaction components and incubate 1 hour at 42C. Add the first-strand cDNA product to the second-strand reaction components and incubate for 2 hours at 16 C. Double-strand cDNA was purified using QIAquick purification kit (Qiagen), eluted twice, each time with 30μl of nuclease-free water then dried in a SpeedVac concentrator. Prepare IVT mix of biotinylated UTP, ribonucleotides, and the 10x T7 enzyme mix and add to the resuspended cDNA. Incubate at 37C for 14 hours. Purify cRNA using RNeasy Mini Kit (Qiagen) and elute the cRNA twice, each time with 50 μl nuclease-free water. Measure the absorbance at 260 nm and 280 nm to determine the ratio (A260:A280=2). In 25 μl total volume, add 10 μg of cRNA to 5 μl of 5x fragmentation buffer and incubate at 94 C for 20 min. Bring 10 μg of fragmented cRNA, 78 μl of hybridization buffer component A, and 130 μl of hybridization buffer component B to a final volume of 260 μl with water. Incubate at 90C for 5 min and immediately chill on ice for 5 min. Slowly inject 250 μl of hybridization reaction mixture into array input port and seal ports with sealing strips. Set the shaker speed to 300 rpm and incubate slides for 18 hours at 37C in an Innove 4080 shaker. Remove the Flex Chamber using the hybridization removal tool. Then, place the bioarrays into the bioarray rack while it sits inside the medium reagent reservoir containing 0.75xTNT. Transfer the bioarray rack to the large reagent reservoir containing preheated 0.75xTNT, and incubate at 46 C for exactly 1 hour. Fill each slot of the small reagent reservoir with 3.4 ml of Cy5-Streptavidin working solution. Transfer the bioarray rack from the large reagent reservoir in to the small reagent reservoir and incubate bioarrays at RT for 30 min. Wash the bioarrays four times with 1xTNT at RT for 5 min. Rinse the bioarrays in 0.1xSSC/0.05%Tween by moving rack up and down 5 times in 5 seconds. Immediately follow the rinse with centrifugation to dry bioarrays, and store dried bioarrays in the dark. We scanned bioarrays with Axon GenePix 4000B and analyzed with CodeLink Expression Analysis software version 2.3.2. The 10,000 spot intensities on the scanned microarray image were normalized to a median value of 1 and data were exported for analysis with CodeLink Expression Analysis software version 2.3.2
Project description:Lymphoma is characterized by heterogeneous biology, pathologic features, and clinical outcome. This has been proven by accumulating pathologic and molecular evidence attributed to underlying aberrant alterations at genetic, epigenetic, transcriptional, protein, microenvironmental levels, and dysregulated oncogenic signaling pathways. In the era of precision medicine, targeting oncogenic pathways to design drugs and to optimize treatment regimens for the lymphoma patients is feasible and clinically significant. As such, further understanding of the biology and the mechanisms behind lymphoma development and identification of oncogenic pathway activation and pathway-based biomarkers to better design precise therapies are challenging but hopeful. Furthermore, pathway-based targeted therapies in combination with traditional chemotherapy, single specific targeted antibody therapy, and immunotherapy might raise the hope for the patients with lymphoma, especially for relapsed and refractory lymphoma patients.
Project description:Interest in preclinical drug development for ovarian cancer has stimulated development of patient-derived xenograft (PDX) or tumorgraft models. However, the unintended formation of human lymphoma in severe combined immunodeficiency (SCID) mice from Epstein-Barr virus (EBV)-infected human lymphocytes can be problematic. In this study, we have characterized ovarian cancer PDXs which developed human lymphomas and explore methods to suppress lymphoproliferative growth. Fresh human ovarian tumors from 568 patients were transplanted intraperitoneally in SCID mice. A subset of PDX models demonstrated atypical patterns of dissemination with mediastinal masses, hepatosplenomegaly, and CD45-positive lymphoblastic atypia without ovarian tumor engraftment. Expression of human CD20 but not CD3 supported a B-cell lineage, and EBV genomes were detected in all lymphoproliferative tumors. Immunophenotyping confirmed monoclonal gene rearrangements consistent with B-cell lymphoma, and global gene expression patterns correlated well with other human lymphomas. The ability of rituximab, an anti-CD20 antibody, to suppress human lymphoproliferation from a patient's ovarian tumor in SCID mice and prevent growth of an established lymphoma led to a practice change with a goal to reduce the incidence of lymphomas. A single dose of rituximab during the primary tumor heterotransplantation process reduced the incidence of CD45-positive cells in subsequent PDX lines from 86.3% (n = 117 without rituximab) to 5.6% (n = 160 with rituximab), and the lymphoma rate declined from 11.1% to 1.88%. Taken together, investigators utilizing PDX models for research should routinely monitor for lymphoproliferative tumors and consider implementing methods to suppress their growth.
Project description:Multiple myeloma (MM) is the second most common hematologic malignancy. While major advances have been made in the disease, it is still incurable. Although antifolate-based drugs are not commonly used to treat myeloma, new generation analogs with distinct patterns of preclinical and clinical activity may offer an opportunity to identify new classes of potentially active drugs. Pralatrexate (PDX), which was approved for the treatment of relapsed or refractory peripheral T-cell lymphoma in 2009, may be one such drug. Pralatrexate exhibits a potency and pattern of activity distinct from its predecessors like methotrexate (MTX). We sought to understand the activity and mechanisms of resistance of multiple myeloma to these drugs, which could also offer potential strategies for selective use of the drug. We demonstrate that PDX and MTX both induce a significant decrease in cell viability in the low nanomolar range, with PDX exhibiting a more potent effect. We identified a series of myeloma cell lines exhibiting markedly different patterns of sensitivity to the drugs, with some lines frankly resistant, and others exquisitely sensitive. These differences were largely attributed to the basal RFC (Reduced Folate Carrier) mRNA expression levels. RFC mRNA expression correlated directly with rates of drug uptake, with the most sensitive lines exhibiting the most significant intracellular accumulation of pralatrexate. This mechanism explains the widely varying patterns of sensitivity and resistance to pralatrexate in multiple myeloma cell lines. These findings could have implications for this class of drugs and their role in the treatment of multiple myeloma.
Project description:MicroRNAs expression profile was acquired in 99 frozen tissues corresponding to 14 Burkitt's lymphoma, 17 diffuse large B-cell lymphoma, 29 follicular lymphoma, 19 mantle cell lymphoma, 8 primary mediastinal B-cell lymphoma and 12 lymph nodes. Additionally, we performed microRNA expression profile of 14 Burkitts' lymphoma cell lines, 2 mantle cell lymphoma cell lines, 5 acute lymphoblastic leukemia cell preparations, 5 samples of mononucleosis cells, 4 Epstein Barr virus infected lymphoblastoid cell lines (EBV), 27 purified samples of B cells at different stage of development (13 GC-CD23-/CD39-, 11 GC-CD5- and 3 GC-CD5+), 4 peripheral blood CD19+ B cells, 4 purified samples of T cells (2 CD4+ and 2 CD8+) and 2 samples of bone marrow CD34+ cells. The data were used to discriminate among diverse pathological and nonpathological samples and to identify microRNAs expression differences between pathological samples and their nonpathological counterparts.