Project description:Comparison of genomic alterations of primary colorectal cancers with liver metastases of the same patient Keywords: array CGH, colorectal cancer, colon cancer, liver metastasis
Project description:Comparison of genomic alterations of primary colorectal cancers with liver metastases of the same patient Keywords: array CGH, colorectal cancer, colon cancer, liver metastasis 21 primary colorectal cancers and 21 matched liver metastases hybridized against sex-matched control pools
Project description:Purpose: At diagnosis, colorectal cancer presents with synchronous peritoneal metastasis in up to 10% of patients. The peritoneum is poorly characterized with respect to its super-specialised microenvironment. Our aim was to describe the differences between peritoneal metastases and their matched primary tumours excised simultaneously at the time of surgery. Also, we tested the hypothesis of these differences being present in primary colorectal tumours and having prognostic capacity. Experimental design: We report a comprehensive analysis of thirty samples from peritoneal metastasis with their matched colorectal cancer primaries obtained during cytoreductive surgery. We tested and validated the prognostic value of our findings in a pooled series of 660 colorectal cancer primary samples with overall survival (OS) information and 743 samples with disease free survival (DFS) information from publicly available databases. Results: We identified 20 genes dysregulated in peritoneal metastasis that promote an early increasing role of ‘stemness’ in conjunction with tumour favorable inflammatory changes. When adjusted for age, gender and stage, the 20-gene peritoneal signature proved to have prognostic value for both OS (adjusted-hazard ratio (HR) for the high-risk group (vs low-risk) 2.32 (95% confidence interval (CI) 1.69-3.19; p-value < 0.0001)) and for DFS (adjusted-HR 2.08 (95%CI 1.50-2.91; p-value < 0.0001)). Conclusions: Our findings indicated that the activation of “stemness” pathways and adaptation to the peritoneal specific environment are key to early stages of peritoneal carcinomatosis. The in-silico analysis suggested that this 20-gene peritoneal signature may hold prognostic information with potential for development of new precision medicine strategies in this setting.
Project description:To identify and characterize differentially expressed tsRNA, we collected 3 primary tissues and 3 liver metastasis tissues in pancreatic cancer, and compared the tsRNA expression profiles between primary tissues and liver metastasis tissues in pancreatic cancer using tsRNA sequencing.
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.
Project description:Gastric cancer is one of the most aggressive cancers and is the second leading cause of cancer death worldwide. Approximately 40% of global gastric cancer cases occur in China, with peritoneal metastasis being the prevalent form of recurrence and metastasis in advanced disease (>50%). Currently, there are limited clinical approaches for predicting and treatment of peritoneal metastasis, resulting in a 6- month average survival time. By comprehensive genome analysis will uncover the pathogenesis of peritoneal metastasis. Here we describe a comprehensive whole-genome and transcriptome sequencing analysis of one advanced gastric cancer case, including non-cancerous mucosa, primary cancer and matched peritoneal metastatic cancer. The peripheral blood is used as normal control.
Project description:Peritoneal carcinomatosis (PC) originating from colorectal cancer (CRC) is associated with a poor prognosis and rapid disease progression. Metastasis is the major cause of death in patients with CRC whereas primary locoregionally circumscribed tumors are mostly curable. Due to the lack of appropriate and realistic mouse models for metastasis of CRC until recently, the research about metastasis of these tumors and possible therapeutic options is still in its infancy. With the establishment of murine CRC tumor organoids, mouse models were established which realistically mimic the process of tumor cell metastasis to the liver and the lung. However, to date no appropriate model for PC is described. Here, we establish a realistic model for peritoneal metastasis of colorectal cancer upon surgical transplantation of tumor organoids into the cecum wall. This mouse model for PC recapitulates human PC which makes it an ideal model for research of the biology of metastasis of colorectal cancer to the peritoneal cavity and for its usage for preclinical drug screening as well as for the evaluation of new therapeutic approaches which are highly needed in clinical reality.