Project description:We compared the expression of genes related to inflammatory cytotoxic functions between MSI and MSS (HLA class I negative and positive) gastrointestinal adenocarcinomas (GIACs), seeking evidence of differences in inflammatory mediators and cytotoxic T-cell responses. Twenty-two GIACs were divided into three study groups as a function of HLA class I expression and MSI phenotype. Comparison between eight high-level MSI (MSI-H) and 8 MSS/HLA+ (control) cancers identified 2170 differentially expressed genes (p< 0.05) after microarray analysis on the Affymetrix HG-U133-Plus-PM plate. We grouped genes in Gene Ontology functional categories: apoptotic programme (119 genes, p=5.1·10-7), leukocyte activation (32 genes, p=0.01), T cell activation (20 genes, p= 0.01), and cytokine production (19 genes, p= 0.04). Real-time RT-PCR and immunohistochemical evaluation were used to confirm some microarray data, finding that increased mRNA levels of pro-inflammatory cytokines and cytotoxic mediators were associated with greater infiltration by CD8+ T lymphocytes in the MSI-H group (p<0.001). Finally, tumours with immunohistochemical HLA class I negative pattern were not grouped together but rather in accordance with features of the gene expression profile of MSI or MSS tumours. As expected, genes associated with antigen processing machinery and MHC class I molecules (TAP2, B2m) were downregulated in MSS/HLA-ABC negative CRCs. In conclusion, microarray and immunohistochemical data may be useful to comprehensively assess tumour-host interactions and differentiate MSI from MSS cancers. The two types of tumours, MSI/HLA- and MSS/HLA-, showed marked differences in the composition and intensity of infiltrating leukocytes, suggesting that their immune escape strategies involve distinct pathways. Case-control study. Samples were selected according to immunological criteria: those with total loss of HLA antigens and those without alterations in the expression of HLA molecules. In addition, the microsatellite instability genotype of all the samples was also analyzed, resulting in microsatellite stability (MSS) and microsatellite instability (MSI) samples. Therefore, three groups of samples were selected: MSS/HLA+, MSS/HLA-, and MSI. The MSS/HLA+ group was used as the control.

Project description:Most cancer deaths are caused by metastases, which are the end-results of circulating tumor cells (CTC) that detach from the cancer primary and succeed to survive in distant organs. The aim of the present study was to develop a gene signature of CTC and to assess its prognostic relevance after surgery for pancreatic ductaladenocarcinoma (PDAC). A negative depletion fluorescence activated cell sorting (FACS) procedure was developed and validated with spiking experiments using cancer cell lines in whole human blood samples. This FACS-based method was used to enrich for CTC from the blood of 10 patients who underwent surgery for PDAC. Total RNA was isolated from 4 subgroup samples, i.e. CTC, haematological cells (G), original tumor (T), and non-tumoral pancreatic control tissue (P). After RNA quality control, samples of 6 patients were eligible for further analysis. Whole genome microarray analysis was performed after double linear amplification of RNA. The ‘Ingenuity Pathway Analysis’ software and AmiGO were used for functional data analyses. A CTC gene signature was developed and validated with the nCounter system on expression data of 78 primary PDAC using Cox regression analysis for disease-free (DFS) and overall survival (OS). Using stringent statistical analysis, we finally retained 8,152 genes to compare expression profiles of CTC vs. other subgroups, and found 1,059 genes to be differentially expressed. The pathway with the highest expression ratio in CTC was p38 mitogen-activated protein kinase (p38 MAPK) signaling, known to be involved in cancer cell migration. In the p38 MAPK pathway TGF-β1, cPLA2, and MAX were significantly upregulated. In addition, 9 other genes associated with both p38 MAPK signaling and cell motility were over-expressed in CTC. High co-expression of TGF-1 and our cell motility panel (≥ 4 out of 9 genes for DFS and ≥ 4 out of 9 genes for OS) in primary PDAC was identified as an independent predictor of DFS (p=0.041, HR (95% CI) = 1.885 (1.025 – 3.559)) and OS (p=0.047, HR (95% CI) = 1.366 (1.004 – 1.861)). Pancreatic CTC isolated from blood samples using a FACS-based negative depletion method,express a cell motility gene signature. The expression of this newly defined cell motility gene signature in the primary tumor is able to predict survival of patients who undergo surgical resection for pancreatic cancer. Total RNA was isolated from circulation tumor samples (CTC), haematological cells (G), original tumor (T), and non-tumor pancreatic control tissue (P) of patients with pancreatic ductal adenocarcinoma (PDAC). Gene expression profiles of CTC were compared to G, T, and P. The aim of the current study was to develop a ‘negative depletion strategy’ to isolate CTC without the exclusion of any particular subset of CTC, and to study their gene-expression profiles in order to find novel therapeutic targets and prognostic markers in patients with pancreatic cancer.

Project description:Metastatic colorectal cancer (mCRC) relies on the detachment of aggressive malignant cells from the primary tumor into the bloodstream, these Circulating Tumor Cells (CTC) being the principal source of the further metastasis. Here, we approached the massive molecular profiling of the CTC population isolated from mCRC patients. Clinically, the presence of CTC is associated with poor prognosis and there exists a clear necessity for more specific and efficient chemotherapies in the treatment of mCRC. Immunoisolation of CTC from these patients combined with a whole transcriptome amplification and hybridization onto gene expression arrays, lead us to specifically describe for the first time a CTC population with adhesive and migratory characteristics, in addition to a modulated expression of genes related to cell death and survival. Furthermore, bioinformatic analysis provided with an armamentarium of highly specific and sensitive valuable markers that should impact on the management and follow-up of mCRC patients. Finally, molecular profiling of CTC resulted in the identification of new therapeutic targets, like TGF-Î²1 impairing, specifically targeting the CTC population which should improve the efficacy in the eradication and prevention of CRC metastasis. In conclusion, molecular profiling of CTC represents an innovative and promising approach in the clinical management of mCRC patients. Circulating Tumor Cells (CTC) were immunoisolated from six metastatic colorectal patients (mCRC). Moreover, blood from three healthy donors were obtained, immunoisolating non-specific cellularity background. RNA was extracted and globally amplified with a Whole Transcriptome Amplification system. Samples were hybridized onto agilent arrays and CTC specific genes were obtained. Gene networks were built with IPA software and a gene ontology analysis was performed. Eleven candidate genes were validated by real time PCR. Finally, TGFB1 was evaluated as a potential drugable target against CTC population.

Project description:Most cancer deaths are caused by metastases, which are the end-results of circulating tumor cells (CTC) that detach from the cancer primary and succeed to survive in distant organs. The aim of the present study was to develop a gene signature of CTC and to assess its prognostic relevance after surgery for pancreatic ductaladenocarcinoma (PDAC). A negative depletion fluorescence activated cell sorting (FACS) procedure was developed and validated with spiking experiments using cancer cell lines in whole human blood samples. This FACS-based method was used to enrich for CTC from the blood of 10 patients who underwent surgery for PDAC. Total RNA was isolated from 4 subgroup samples, i.e. CTC, haematological cells (G), original tumor (T), and non-tumoral pancreatic control tissue (P). After RNA quality control, samples of 6 patients were eligible for further analysis. Whole genome microarray analysis was performed after double linear amplification of RNA. The ‘Ingenuity Pathway Analysis’ software and AmiGO were used for functional data analyses. A CTC gene signature was developed and validated with the nCounter system on expression data of 78 primary PDAC using Cox regression analysis for disease-free (DFS) and overall survival (OS). Using stringent statistical analysis, we finally retained 8,152 genes to compare expression profiles of CTC vs. other subgroups, and found 1,059 genes to be differentially expressed. The pathway with the highest expression ratio in CTC was p38 mitogen-activated protein kinase (p38 MAPK) signaling, known to be involved in cancer cell migration. In the p38 MAPK pathway TGF-β1, cPLA2, and MAX were significantly upregulated. In addition, 9 other genes associated with both p38 MAPK signaling and cell motility were over-expressed in CTC. High co-expression of TGF-1 and our cell motility panel (≥ 4 out of 9 genes for DFS and ≥ 4 out of 9 genes for OS) in primary PDAC was identified as an independent predictor of DFS (p=0.041, HR (95% CI) = 1.885 (1.025 – 3.559)) and OS (p=0.047, HR (95% CI) = 1.366 (1.004 – 1.861)). Pancreatic CTC isolated from blood samples using a FACS-based negative depletion method,express a cell motility gene signature. The expression of this newly defined cell motility gene signature in the primary tumor is able to predict survival of patients who undergo surgical resection for pancreatic cancer.

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Systematic screening of prognostic and recurrence markers of colorectal cancer and construction of survival prediction model

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