CHD1L Expression Increases Tumor Progression and Acts as a Predictive Biomarker for Poor Prognosis in Pancreatic Cancer
DIGESTIVE DISEASES AND SCIENCES
Authors: Liu, Chuan; Fu, Xiaowei; Zhong, Zhiwei; Zhang, Jing; Mou, Haiyan; Wu, Qiong; Sheng, Tianle; Huang, Bo; Zou, Yeqing
Abstract
The chromodomain helicase/ATPase DNA binding protein 1-like gene (CHD1L) plays a key role in controlling various cellular phenomena, including immune-mediated inflammation, transformation, apoptosis, cell cycle progression, and proliferation. This study investigated the function and clinical significance of CHD1L protein expression in pancreatic cancer (PC). We analyzed CHD1L expression in surgical specimens from 112 PC patients. The correlation between the clinical characteristics and prognosis was also determined. Futhermore, cell proliferation were measured using EDU, and a molecular mechanism of Wnt/beta-catenin pathway regulation by CHD1L was explored. CHD1L protein expression was significantly higher in PC patients with regard to the tumor grade, stage, size, differentiation and lymph node status. Increased CHD1L protein expression was significantly associated with poor overall survival. Multivariate analyses revealed that high CHD1L expression was an independent predictive marker for the recurrence and poor prognosis of pancreatic cancer. Furthermore, silencing of CHD1L expression by RNAi effectively abolished the proliferative abilities of CHD1L in vivo and in vitro. We found that the Wnt/beta-catenin pathway contributed to the effect of CHD1L-mediated pancreatic cancer proliferation. Taken together, our data provide a novel evidence for the biological and clinical significance of CHD1L as a potential biomarker, and we demonstrate that CHD1L-Wnt/beta-catenin might be a novel pathway involved in pancreatic cancer progression.
Understanding the impact of 1q21.1 copy number variant
ORPHANET JOURNAL OF RARE DISEASES
Authors: Harvard, Chansonette; Strong, Emma; Mercier, Eloi; Colnaghi, Rita; Alcantara, Diana; Chow, Eva; Martell, Sally; Tyson, Christine; Hrynchak, Monica; McGillivray, Barbara; Hamilton, Sara; Marles, Sandra; Mhanni, Aziz; Dawson, Angelika J.; Pavlidis, Paul; Qiao, Ying; Holden, Jeanette J.; Lewis, Suzanne M. E.; O'Driscoll, Mark; Rajcan-Separovic, Evica
Abstract
Background: 1q21.1 Copy Number Variant (CNV) is associated with a highly variable phenotype ranging from congenital anomalies, learning deficits/intellectual disability (ID), to a normal phenotype. Hence, the clinical significance of this CNV can be difficult to evaluate. Here we described the consequences of the 1q21.1 CNV on genome-wide gene expression and function of selected candidate genes within 1q21.1 using cell lines from clinically well described subjects. Methods and Results: Eight subjects from 3 families were included in the study: six with a 1q21.1 deletion and two with a 1q21.1 duplication. High resolution Affymetrix 2.7M array was used to refine the 1q21.1 CNV breakpoints and exclude the presence of secondary CNVs of pathogenic relevance. Whole genome expression profiling, studied in lymphoblast cell lines (LBCs) from 5 subjects, showed enrichment of genes from 1q21.1 in the top 100 genes ranked based on correlation of expression with 1q21.1 copy number. The function of two top genes from 1q21.1, CHD1L/ALC1 and PRKAB2, was studied in detail in LBCs from a deletion and a duplication carrier. CHD1L/ALC1 is an enzyme with a role in chromatin modification and DNA damage response while PRKAB2 is a member of the AMP kinase complex, which senses and maintains systemic and cellular energy balance. The protein levels for CHD1L/ALC1 and PRKAB2 were changed in concordance with their copy number in both LBCs. A defect in chromatin remodeling was documented based on impaired decatenation (chromatid untangling) checkpoint (DCC) in both LBCs. This defect, reproduced by CHD1L/ALC1 siRNA, identifies a new role of CHD1L/ALC1 in DCC. Both LBCs also showed elevated levels of micronuclei following treatment with a Topoisomerase II inhibitor suggesting increased DNA breaks. AMP kinase function, specifically in the deletion containing LBCs, was attenuated. Conclusion: Our studies are unique as they show for the first time that the 1q21.1 CNV not only causes changes in the expression of its key integral genes, associated with changes at the protein level, but also results in changes in their known function, in the case of AMPK, and newly identified function such as DCC activation in the case of CHD1L/ALC1. Our results support the use of patient lymphoblasts for dissecting the functional sequelae of genes integral to CNVs in carrier cell lines, ultimately enhancing understanding of biological processes which may contribute to the clinical phenotype.