Diagnosis of thymic epithelial tumor subtypes by a quantitative proteomic approach
ANALYST
Authors: Zhao, Ting; Wu, Jie; Liu, Xiaohui; Zhang, Lei; Chen, Gang; Lu, Haojie
Abstract
The histological typing of thymic epithelial tumours (TETs) still remains a challenge for surgical pathologists, especially when encountering borderline cases mainly focused on spindle cell types (including type A, atypical type A (aA), AB, and B3). A systematic proteomics analysis of TETs was performed using isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MS/MS). In total, 6479 and 6305 proteins were identified and quantified, respectively. After Gene Ontology (GO) annotation and Ingenuity Pathway Analysis (IPA), six differentially expressed proteins were validated by tissue microarray or multiple reaction monitoring (MRM) quantification. ABCE1 and CLIC2 are promising to be diagnostic candidate biomarkers in thymic carcinomas (TCs). CHD1L was up-regulated in type AB and type B thymomas compared with type A thymoma. Both CLIC2 and MAP7 were negatively detected in type B1 and B2 thymomas. SMAD4 was overexpressed in type aA thymomas and TCs. CDC42 was significantly down-regulated in type B2 thymomas compared with other subtypes. Six novel candidate biomarkers were found to be useful in differentiating subtypes of TETs. SMAD4 may play a specific role in tumorigenesis and the development of aA thymomas and thymic carcinomas.
CHD1L: a new candidate gene for congenital anomalies of the kidneys and urinary tract (CAKUT)
NEPHROLOGY DIALYSIS TRANSPLANTATION
Authors: Brockschmidt, Antje; Chung, Boidinh; Weber, Stefanie; Fischer, Dagmar-Christiane; Kolatsi-Joannou, Maria; Christ, Laura; Heimbach, Andre; Shtiza, Diamant; Klaus, Guenter; Simonetti, Giacomo D.; Konrad, Martin; Winyard, Paul; Haffner, Dieter; Schaefer, Franz; Weber, Ruthild G.
Abstract
Background. Recently, we identified a microduplication in chromosomal band 1q21.1 encompassing the CHD1L/ALC1 gene encoding a chromatin-remodelling enzyme in congenital anomalies of the kidneys and urinary tract (CAKUT) patient. Methods. To explore the role of CHD1L in CAKUT, we screened 85 CAKUT patients for mutations in the CHD1L gene and performed functional analyses of the three heterozygous missense variants detected. In addition, we quantitatively determined CHD1L expression in multiple human fetal and adult tissues and analysed expression of CHD1L protein in human embryonal, adult and hydronephrotic kidney sections. Results. Two of three novel heterozygous missense variants identified in three patients were not found in >400 control chromosomes. All variants lead to amino acid substitutions in or near the CHD1L macro domain, a poly-ADP-ribose (PAR)-binding module interacting with PAR polymerase 1 (PARP1), and showed decreased interaction with PARP1 by pull-down assay of transfected cell lysates. Quantitative messenger RNA analysis demonstrated high CHD1L expression in human fetal kidneys, and levels were four times higher than in adult kidneys. In the human embryo at 7-11 weeks gestation, CHD1L immunolocalized in the early ureteric bud and the S-and comma-shaped bodies, critical stages of kidney development. In normal postnatal sections, CHD1L was expressed in the cytoplasm of tubular cells in all tubule segments. CHD1L expression appeared higher in the hydronephrotic kidney of one patient with a hypofunctional CHD1L variant than in normal kidneys, recapitulating high fetal levels. Conclusion. Our data suggest that CHD1L plays a role in kidney development and may be a new candidate gene for CAKUT.