Determining differentially expressed miRNAs and validating miRNA-target relationships using the SPRET/Ei mouse strain
MAMMALIAN GENOME
Authors: Timmermans, S.; Van Hauwermeiren, F.; Puimege, L.; Dejager, L.; Van Wonterghem, E.; Vanhooren, V.; Mestdagh, P.; Libert, C.; Vandenbroucke, R. E.
Abstract
Micro RNAs (miRs) are involved in many biological processes. The challenge of identifying genes influenced by miRs is evidenced by the relatively few validated miR-target interactions. In this work, we used the Mus spretus SPRET/Ei strain as an in vivo system to identify new miR-target relations. Mus spretus diverged from Mus musculus over one million years ago, making it genetically and phenotypically divergent. SPRET/Ei mice are resistant to inflammation and several cancers, making them attractive for different research fields. Their phenotype is unique and is considerably different from that of almost all other laboratory mouse strains. We exploited the characteristics of SPRET/Ei mice as a tool to identify miR-target relationships. Hepatic genes and miRs differentially expressed between C57BL/6 and SPRET/Ei mice at basal levels were identified with an Affymetrix microarray and a multiplex qPCR, respectively. A total of 955 genes and 38 miRs were identified as differentially expressed. Increased miR expression might result in downregulation of its target mRNA and vice versa. Subsequently, we used our miR and mRNA data to identify possible in vivo miR-target interactions. Ingenuity pathway analysis (IPA) analysis revealed 380 possible miR-target interactions. Five miRs were selected for experimental validation by in vivo overexpression of the miRs. This resulted in the confirmation of six previously unknown miR-target interactions: miR-146a, Zdhhc2; miR-150, Elovl3, Kcnk5, and Nrd1d2; miR-155, Camta1; and miR-592, Steap2. In conclusion, we show that SPRET/Ei mice can be used as a platform for miR-target identification in vivo, and we used this platform to identify and experimentally confirm miR-target interactions.
Reduced Expression of ZDHHC2 Is Associated with Lymph Node Metastasis and Poor Prognosis in Gastric Adenocarcinoma
PLOS ONE
Authors: Yan, Shu-Mei; Tang, Jian-Jun; Huang, Chun-Yu; Xi, Shao-Yan; Huang, Ma-Yan; Liang, Jian-Zhong; Jiang, Yuan-Xue; Li, Yu-Hong; Zhou, Zhi-Wei; Ernberg, Ingemar; Wu, Qiu-Liang; Du, Zi-Ming
Abstract
Background: Zinc finger, DHHC-type containing 2 (ZDHHC2), originally named as reduced expression associated with metastasis protein (REAM), has been proposed as a putative tumor/metastasis suppressor gene and is often aberrantly decreased in human cancers. However ZDHHC2 expression pattern and its clinical significance have not yet been investigated in gastric adenocarcinoma. Methodology/Principal Findings: Quantitative Real-Time PCR (qRT-PCR) and immunostaining were performed to detect ZDHHC2 expression in gastric adenocarcinoma, and then the correlation between ZDHHC2 expression and clinicpathologic parameters, and patient survival was analyzed. Compared to the adjacent normal tissues, ZDHHC2 expression was significantly reduced in gastric tumor tissues as shown by qRT-PCR and immunostaining. Low expression of ZDHHC2 was observed in 44.7% (211/472) of gastric adenocarcinoma patients, and was associated significantly with lymph node metastasis (p<0.001) and histological grade (p<0.001). Multivariate Cox regression analysis indicated that ZDHHC2 expression had a significant, independent predictive value for survival of gastric cancer patients (HR = 0.627, p = 0.001). Conclusions/Significance: Our data suggest that reduced ZDHHC2 expression is associated with lymph node metastasis and independently predicts an unfavorable prognosis in gastric adenocarcinoma patients.