Project description:Recent randomized clinical trial revealed the additional effect of bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF)-A, to conventional chemotherapy on survival of patients with metastatic colorectal cancer. However, a number of preclinical reports indicate resistant mechanisms to anti-angiogenic therapy in several tumor models. We investigated the phenotypic alterations of colorectal cancer xenograft during antiangiogenic therapy. TK-4, a solid tumor strain derived from human colon cancer, was orthotopically implanted into cecal walls of nude mice and treated with anti-VEGF antibody or control IgG for 35 days. Gene expression was analyzed using microarrays (Human Gene 1.0ST Array, Affymetrix).
Project description:RSPO is a WNT pathway activator and functions as a potent regulator of stem cell growth in colon. RSPO family members were produced by several human tumors representing multiple tumor types including ovarian, pancreatic, colon, breast and lung cancer. Specific monoclonal antibody antagonists of RSPO family members were developed. In human patient-derived tumor xenograft models, anti-RSPO treatment markedly inhibited tumor growth either as single agents or in combination with chemotherapy. Furthermore, blockade of RSPO signaling reduced the tumorigenicity of cancer cells based on serial transplantation studies. In order to assess the impact of RSPO3 inhibition and gain insight in the anti-RSPO3 treatment mechanism of action, the global gene expression profiles of 4 human colorectal cancer patient derived models (PDX) were performed using Affymetrix microarray for the xenografts treated by the anti-RSPO3 antibody.
Project description:Recent randomized clinical trial revealed the additional effect of bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF)-A, to conventional chemotherapy on survival of patients with metastatic colorectal cancer. However, a number of preclinical reports indicate resistant mechanisms to anti-angiogenic therapy in several tumor models. We investigated the phenotypic alterations of colorectal cancer xenograft during antiangiogenic therapy.
Project description:To investigate the underlying mechanisms of the inhibitory effects of human anti-human FGFR2IIIc antibody on growth and migration of colorectal cancer cells, we used DNA microarray analysis to examine the cell signaling pathway alterations following the administration of anti-FGFR2IIIc antibody. Cells were plated at a density of 2.5 M-CM-^W 105 cells in a 60-mm dish, and grown overnight. Then 100 M-NM-<g/mL of monoclonal anti-human FGFR2IIIc antibody was added in each dish. For control groups, an equal amount of anti-GFP antibody was added in another dish. After 48 hr, total RNA was isolated from cells. For use in DNA microarray analysis, 50 ng RNA from each group of cells was labeled using the Low Input Quick Amp Labeling kit. Labeled RNA was further purified using the Qiagen RNeasy Mini kit. Labeled cRNA was hybridized to the Agilent human 44k oligonucleotide microarray, and washed using Agilent Gene Expression washing buffer.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Immune surveillance escaping is essential for survival of original tumor. Considering PB-020’s good pharmacokinetic properties, combined effect of PB-020 and immunotherapy drugs is worth studying. As PB-020 can effectively suppress mouse colorectal cancer cell lines in cell culture, we tested the effect of combining PB-020 with the anti-PD-1 monoclonal antibody RMP1-14 on the growth of subcutaneously implanted MC38 cells to C57BL/6 mice as a syngeneic mouse model of colorectal cancer. To clarify the molecular mechanism underling this anti-cancer therapy, we executed RNA sequencing of tumor sample obtained from the experiment above.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.