Gene expression signature of non-involved lung tissue associated with survival in lung adenocarcinoma patients
CARCINOGENESIS
Authors: Galvan, Antonella; Frullanti, Elisa; Anderlini, Marco; Manenti, Giacomo; Noci, Sara; Dugo, Matteo; Ambrogi, Federico; De Cecco, Loris; Spinelli, Roberta; Piazza, Rocco; Pirola, Alessandra; Gambacorti-Passerini, Carlo; Incarbone, Matteo; Alloisio, Marco; Tosi, Davide; Nosotti, Mario; Santambrogio, Luigi; Pastorino, Ugo; Dragani, Tommaso A.
Abstract
Lung adenocarcinoma patients of similar clinical stage and undergoing the same treatments often have marked interindividual variations in prognosis. These clinical discrepancies may be due to the genetic background modulating an individual's predisposition to fighting cancer. Herein, we hypothesized that the lung microenvironment, as reflected by its expression profile, may affect lung adenocarcinoma patients' survival. The transcriptome of non-involved lung tissue, excised from a discovery series of 204 lung adenocarcinoma patients, was evaluated using whole-genome expression microarrays (with probes corresponding to 28 688 well-annotated coding sequences). Genes associated with survival status at 60 months were identified by Cox regression analysis (adjusted for gender, age and clinical stage) and retested in a validation series of 78 additional cases. RNA-Seq analysis from non-involved lung tissue of 12 patients was performed to characterize the different isoforms of candidate genes. Ten genes for which the log e transformed hazard ratios expressed the same direction of effect in the discovery (P < 1.0 x 10(-3)) and validation series comprised the gene expression signature associated with survival: CNTNAP1, PKNOX1, FAM156A, FRMD8, GALNTL1, TXNDC12, SNTB1, PPP3R1, SNX10 and SERPINH1. RNA sequencing highlighted the complex expression pattern of these genes in non-involved lung tissue from different patients and permitted the detection of a read-through gene fusion between PPP3R1 and the flanking gene (CNRIP1) as well as a novel isoform of CNTNAP1. Our findings support the hypothesis that individual genetic characteristics, evidenced by the expression pattern of non-involved tissue, influence the outcome of lung adenocarcinoma patients.
Caspr Controls the Temporal Specification of Neural Progenitor Cells through Notch Signaling in the Developing Mouse Cerebral Cortex
CEREBRAL CORTEX
Authors: Wu, Zhi-Qiang; Li, Di; Huang, Ya; Chen, Xi-Ping; Huang, Wenhui; Liu, Chun-Feng; Zhao, He-Qing; Xu, Ru-Xiang; Cheng, Mei; Schachner, Melitta; Ma, Quan-Hong
Abstract
The generation of layer-specific neurons and astrocytes by radial glial cells during development of the cerebral cortex follows a precise temporal sequence, which is regulated by intrinsic and extrinsic factors. The molecular mechanisms controlling the timely generation of layer-specific neurons and astrocytes remain not fully understood. In this study, we show that the adhesion molecule contactin-associated protein (Caspr), which is involved in the maintenance of the polarized domains of myelinated axons, is essential for the timing of generation of neurons and astrocytes in the developing mouse cerebral cortex. Caspr is expressed by radial glial cells, which are neural progenitor cells that generate both neurons and astrocytes. Absence of Caspr in neural progenitor cells delays the production cortical neurons and induces precocious formation of cortical astrocytes, without affecting the numbers of progenitor cells. At the molecular level, Caspr cooperates with the intracellular domain of Notch to repress transcription of the Notch effector Hes1. Suppression of Notch signaling via a Hes1 shRNA rescues the abnormal neurogenesis and astrogenesis in Caspr-deficient mice. These findings establish Caspr as a novel key regulator that controls the temporal specification of cell fate in radial glial cells of the developing cerebral cortex through Notch signaling.