Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

High-throughput microRNA (miRNAs) arrays in pancreatic cancer

ABSTRACT: Background: Only a subset of radically-resected pancreatic ductal adenocarcinoma (PDAC) patients benefit from chemotherapy, and identification of novel prognostic factors is warranted. Recently miRNAs emerged as diagnostic biomarkers and innovative therapeutic targets, while high-throughput arrays are opening new opportunities to evaluate whether they can also predict clinical outcome. The present study evaluated whether comprehensive miRNA expression profiling correlated with overall survival (OS) in resected PDAC patients. Methodology/Principal Findings: High-resolution miRNA profiles were obtained with the Toray’s 3D-GeneTM miRNA chip, detecting more than 1200 types of human miRNA. RNA was isolated from paraffin-embedded primary tumors of 26 radically resected stage-pT3N1 homogeneously treated patients (adjuvant gemcitabine 1000mg/m2/day, days-1/8/15, every 28days), carefully selected according to their outcome (OS<12 vs. OS>30 months, i.e. short/long-OS). Highly stringent statistics included t-test, distance matrix with Spearman-ranked correlation, and iterative approaches. Unsupervised hierarchical analysis revealed that PDAC specimens clustered according to their short/long-OS classification, while the feature selection algorithm RELIEF identified the top-4 discriminating miRNAs between the two groups. These miRNAs target more than 1500 transcripts, including 169 targeted by two or more of these miRNAs. MiR-211 emerged as the best discriminating miRNA, with significantly higher expression in long- vs. short-OS patients. The expression of this miRNA was subsequently assessed by quantitative-PCR in an independent cohort of laser microdissected tumors from 60 resected stage-pT3N1 PDAC patients treated with the same gemcitabine regimen. Patients with low miR-211 expression according to median value had a significantly shorter median OS (14.8, 95%CI=13.1-16.5, vs. 25.7 months, 95%CI=16.2-35.1, log-rank P=0.004). Multivariate analysis demonstrated that low miR-211 expression was an independent factor of poor prognosis (hazard ratio 2.3, P=0.03) after adjusting for all the factors influencing outcome. 19 samples, duplicated gene spots

ORGANISM(S): Homo sapiens

SUBMITTER: Elisa Giovannetti

PROVIDER: E-GEOD-38781 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Background: Only a subset of radically-resected pancreatic ductal adenocarcinoma (PDAC) patients benefit from chemotherapy, and identification of novel prognostic factors is warranted. Recently miRNAs emerged as diagnostic biomarkers and innovative therapeutic targets, while high-throughput arrays are opening new opportunities to evaluate whether they can also predict clinical outcome. The present study evaluated whether comprehensive miRNA expression profiling correlated with overall survival (OS) in resected PDAC patients. Methodology/Principal Findings: High-resolution miRNA profiles were obtained with the Toray’s 3D-GeneTM miRNA chip, detecting more than 1200 types of human miRNA. RNA was isolated from paraffin-embedded primary tumors of 26 radically resected stage-pT3N1 homogeneously treated patients (adjuvant gemcitabine 1000mg/m2/day, days-1/8/15, every 28days), carefully selected according to their outcome (OS<12 vs. OS>30 months, i.e. short/long-OS). Highly stringent statistics included t-test, distance matrix with Spearman-ranked correlation, and iterative approaches. Unsupervised hierarchical analysis revealed that PDAC specimens clustered according to their short/long-OS classification, while the feature selection algorithm RELIEF identified the top-4 discriminating miRNAs between the two groups. These miRNAs target more than 1500 transcripts, including 169 targeted by two or more of these miRNAs. MiR-211 emerged as the best discriminating miRNA, with significantly higher expression in long- vs. short-OS patients. The expression of this miRNA was subsequently assessed by quantitative-PCR in an independent cohort of laser microdissected tumors from 60 resected stage-pT3N1 PDAC patients treated with the same gemcitabine regimen. Patients with low miR-211 expression according to median value had a significantly shorter median OS (14.8, 95%CI=13.1-16.5, vs. 25.7 months, 95%CI=16.2-35.1, log-rank P=0.004). Multivariate analysis demonstrated that low miR-211 expression was an independent factor of poor prognosis (hazard ratio 2.3, P=0.03) after adjusting for all the factors influencing outcome.

Project description:Pancreatic ductal adenocarcinoma (PDAC) remains a major unsolved health problem. Most drugs that pass preclinical tests fail in these patients, emphasizing the need of appropriate preclinical models to test novel anticancer strategies. We developed four orthotopic mouse models employing primary human PDAC cells expressing Firefly and Gaussia luciferases, enabling bioluminescence monitoring of tumor growth and metastasis formation. Additional tumor characterization was performed using MR and high frequency ultrasound imaging. Genomic and immunohistochemical analysis revealed c-Met amplification and overexpression in one of four models. Analysis of c-Met inhibitors in vitro showed that crizotinib had the most potent effect. Moreover, we demonstrated synergistic effects between crizotinib and gemcitabine M-bM-^@M-^S the standard of care therapeutic in PDAC patients - in vitro and in vivo. Importantly, crizotinib reduced the cytidine deaminase activity in PDAC cells causing prolonged activity of gemcitabine due to diminished metabolic inactivation, as measured by LC-MS/MS. This might at least in part explain the observed prolonged survival of concomitantly treated mice with PDAC tumors and metastases. In conclusion, our orthotopic PDAC models enabled PDAC tumor imaging, and showed genetic, histopathological and metastatic features similar to their originator tumors. This allowed the identification of c-Met as a potential therapeutic target in PDAC, and revealed a cytidine deaminase-mediated synergistic mechanism between crizotinib and gemcitabine, a combination of drugs that warrants further investigation for the potential treatment of PDAC patients. 12 test samples in total [4 PDAC models (PDAC-1, PDAC-2, PDAC-3, PDAC-4; in three panel: primary human PDAC, primary tumor culture and mouse sample)] and reference sample (healthy control (mix/pool of healthy volunteers DNA) were analyzed as following (8 hybridizations); PDAC-1 primary human-Cy3 vs PDAC-4 cultured cells -Cy5 PDAC-1 cultured cells-Cy3 vs PDAC-4 mouse-Cy5 PDAC-1 mouse-Cy3 vs reference-Cy5 PDAC-2 primary human-Cy3 vs reference-Cy5 PDAC-2_cultured cells-Cy3 vs PDAC-2 mouse-Cy5 PDAC-3_primary human-Cy3 vs reference-Cy5 PDAC-3_cultured cells-Cy3 vs PDAC-3 mouse-Cy5 PDAC-4 primary human-Cy5 vs reference-Cy3 Normalized log2 ratio of (sample/references) data were calculated for 12 samples [*txt files on Series records]. Description of experimental/analysis design in r-program to generate 12 samples from 8 raw data files is provided in README.txt [Series supplementary file]

Project description:Pancreatic ductal adenocarcinoma (PDAC) is a nearly uniformly lethal malignancy, with most patients facing an adverse clinical outcome. Given the pivotal role of aberrant Notch signaling in the initiation and progression of PDAC, we investigated the effect of MRK-003, a potent and selective γ-secretase inhibitor, in preclinical PDAC models. We used a panel of human PDAC cell lines, as well as patient-derived PDAC xenografts, to determine whether pharmacological targeting of the Notch pathway could inhibit pancreatic tumor growth and potentiate gemcitabine sensitivity. In vitro, MRK-003 treatment downregulated the canonical Notch target gene Hes-1, significantly inhibited anchorage independent growth, and reduced the subset of CD44+CD24+ and aldehyde dehydrogenase (ALDH)+ cells that have been attributed with tumor initiating capacity. Ex vivo pretreatment of PDAC cells with MRK-003 in culture significantly inhibited the subsequent engraftment in immunocompromised mice. In vivo, MRK-003 monotherapy significantly blocked tumor growth in 5 of 9 (56%) patient-derived PDAC xenografts. Moreover, a combination of MRK-003 and gemcitabine showed enhanced antitumor effects compared to gemcitabine alone in 4 of 9 (44%) PDAC xenografts. Baseline gene expression analysis of the treated xenografts indicated that upregulation of nuclear factor kappa B (NFκB) pathway components was associated with the sensitivity to single MRK-003, while upregulation in B-cell receptor (BCR) signaling and nuclear factor erythroid-derived 2-like 2 (NRF2) pathway correlated with response to the combination of MRK-003 with gemcitabine. The preclinical findings presented here provide further rationale for small molecule inhibition of Notch signaling as a therapeutic strategy in PDAC. Pancreatic ductal adenocarcinoma xenografts were grown in Athymic Nude-Foxn1nu mice. RNA was extracted and profiled in Affymetrix platform to identify genes correlating with sensitivity to MRK-003

Dataset Information

High-throughput microRNA (miRNAs) arrays in pancreatic cancer

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets