Project description:Purpose: Even in last stage of metastatic castration-resistant prostate cancer, androgen receptor (AR) signaling remains active.To derive high metastatic prostate cancer (PCa), we labeled AR-positive but castration-resistant 22Rv1 PCa cells with luciferase gene (22Rv1-Luc2) and these cells were orthotopically implanted in mouse prostate for spontaneous progression. Methods: 2 × 10^5 of luciferase-expressing 22Rv1 cells (22Rv1-Luc2) cells were implanted in the anterior prostate of nude mice. After 12-14 weeks, the host mice were necropsied and the metastases from lumbar lymph nodes and primary tumors were dissected under laminar flow. Tumor tissues were minced using sterile scalpels and further digested with Collagenase D for 1 h. The lymph node metastatic cancer cells, named 22Rv1-M1, were orthotopically reimplanted in nude mice. At 12 weeks, the secondary metastases were isolated in the lumbar lymph nodes and designated as 22Rv1-M2 cells. Suspension of 1 × 10^6 22Rv1-M2 cells in DPBS was injected into nude mice through the tail vein, and mice developed metastases (22Rv1-M3) after 6 week. This procedure was repeated once to attain the 22Rv1-M4. Results: 22Rv1-derived metastatic cell lines exhibit increased in vitro and in vivo invasion activity as the progression from 22Rv1 to M4. Transcriptomic analysis of genome-wide gene expression in the M4 tumors reveal the unique gene expression profile compared to 22Rv1 tumors. Conclusions: Transcriptomic data provide the gene network for decoding the mechanism of PCa metastasis.
Project description:Activation of the inflammatory circuits occurs frequently in cancer cells. However the molecular details linking inflammation to transformation and progression are still unknown. In this study we report for the first time, that activation of the ETS factor ESE1 is a key event connecting inflammatory signaling with prostate cancer progression. We report that ESE1 is induced upon IL-1 beta stimulation by NFKB and mediates key transcriptional changes involving cell adhesion, migration and invasion. ESE1 activation in turn induces NFKB transcriptional activation and intranuclear translocation and mediates the transforming phenotypes linked to the activation of IL-1B. Transcriptional signatures and immunohistochemistry revealed that this ESE1-NFKB regulatory circuit also operates in prostate tumors, particularly in those with significant elevation of ESE1. Thus, ESE1 promotes an inflammatory feed forward loop positively leading to prostate cancer progression. Pharmacological NFKB inhibition reverted the transformed status of ESE1 cell lines providing a rationale for context-dependent therapeutic strategies in ESE1 activated tumors. These studies find a previously unrecognized link between ETS and activation of the NFKB pathway and open new avenues for prostate cancer treatment. Gene expression analysis of a control cell line (22Rv1-pcDNA3.1) and a testing cell lines (22Rv1-ESE1), with two replicates, with dye swap, performed for each sample.
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.