Long non-coding RNA MCF2L-AS1 promotes the aggressiveness of colorectal cancer by sponging miR-874-3p and thereby up-regulating CCNE1
JOURNAL OF GENE MEDICINE
Authors: Huang, Fa-Kun; Zheng, Cheng-Ying; Huang, Long-Kai; Lin, Chang-Qing; Zhou, Jun-Feng; Wang, Jia-Xing
Abstract
Background Long non-coding RNAs (lncRNAs) have drawn growing attention because of the role which they play in various diseases, including colorectal cancer (CRC). However, the potential functions of lncRNA MCF2L antisense RNA 1 (MCF2L-AS1) in tumors remained largely unclear. The present study aimed to explore the clinical significance and the biological effects of lncRNA MCF2L antisense RNA 1 (MCF2L-AS1) in CRC. Methods Reverse transcriptase-polymerase chain reaction was performed to determine the expression of MCF2L-AS1 in CRC. The clinical significance of MCF2L-AS1 in CRC patients was analyzed statistically. In vitro experiments were performed to determine the effects of MCF2L-AS1 on the cellular progression of CRC cells. Bioinformatic assays, luciferase reporter assays and RNA-pulldown assays were performed to predict for potential microRNAs that can interact with MCF2L-AS1 and mRNAs that can interact with miR-874-3p. Results We identified a novel CRC-related lncRNA, MCF2L-AS1, which is distinctly highly expressed in CRC. Its diagnostic value for CRC patients was also demonstrated. Clinical assays revealed that high MCF2L-AS1 expression is associated with advanced stages, positive metastasis and the poor prognosis of CRC patients. Multivariate assays confirmed that MCF2L-AS1 expression is an independent poor prognostic factor for both 5-year overall survival and 5-year disease-free survival of CRC patients. Functionally, we confirmed that knockdown of MCF2L-AS1 distinctly suppresses the proliferation, migration and invasion of CRC cells and also promotes apoptosis. Mechanistic investigation showed that MCF2L-AS1 functions as an endogenous sponge for miR-874-3p to increase the expression of CCNE1. Conclusions Our findings identified a novel CRC-related lncRNA, MCF2L-AS1, which may be used as a potential diagnostic and prognostic biomarker for CRC patients. In addition, the newly identified MCF2L-AS1/miR-874-3p/CCNE1 axis can modulate the initiation and progression of CRC.
Aberrant Cell Cycle Progression and Endoreplication in Regenerating Livers of Mice That Lack a Single E-Type Cyclin
GASTROENTEROLOGY
Authors: Nevzorova, Yulia A.; Tschaharganeh, Darjus; Gassler, Nikolaus; Geng, Yan; Weiskirchen, Ralf; Sicinski, Piotr; Trautwein, Christian; Liedtke, Christian
Abstract
BACKGROUND & AIMS: E-cyclins control the transition of quiescent cells into the cell cycle. Two E-cyclins, CcnE1 and CcnE2, have been described, but their specific contributions to cell cycle reentry in vivo are poorly understood. Liver regeneration following partial heparectomy is an excellent in vivo model for the study of cell cycle reentry of quiescent cells. We investigated the relevance of E-cyclins in directing resting hepatocytes into the cell cycle after partial hepatectomy using CcnE1 and CcnE2 knockout mice. METHODS: Partial hepatectomy (70%) was performed in CcnE1 (E1(-/-)) and CcnE2 (E2(-/-)) knockout and wild-type mice. Liver regeneration was monitored by cell cycle markers For G(1)/S phase, S phase, and M phase as well as by determining the liver/body weight ratio after partial hepatectomy. Ploidy of hepatocytes was determined by fluorescence-activated cell sorting and fluorescent in situ hybridization. RESULTS: CcnE1 deletion resulted in normal liver regeneration with a slight delay of the G(1)/S-phase transition and a defect in endoreplication of otherwise polyploid hepatocytes. Surprisingly, E2(-/-) mice displayed accelerated and sustained DNA synthesis after partial hepatectomy, excessive endoreplication in hepatocytes, and a liver mass that was 45% greater than that of wild-type mice after termination of the regeneration process. CcnE2 depletion induced overexpression of CcnE1 and prolonged cdk2 kinase activity after partial hepatectomy. CONCLUSIONS: CcnE2 has an unexpected role in repressing CcnE1; the phenotype of E2(-/-) mice appears to result from CcnE1 overexpression and cdk2 hyperactivation. CcnE1 and CcnE2 therefore have nonredundant functions for S-phase entry and endoreplication during liver regeneration.