ABSTRACT
Gastric cancer(GC)is one of the most common malignancies in the digestive system.Many patients are found in advanced stage and have a poor prognosis.Surgery and chemotherapy remain the main treatments for gastric cancer.N6-methyladenosine(m6A)is a hot topic in tumor research in recent years.As the most common form of RNA modification in eukaryotes,m6A can regulate various stages of the RNA cycle,including RNA splicing,processing,degradation,and translation,thereby regulating RNA expression and function,playing a critical role in various pathways such as cell differentiation,development,and metabolism.The m6A demethylase can remove methyl groups on RNA,ensuring that m6A methylation is a dynamic and reversible process.As a key enzyme in the m6A methylation process,the imbalance of m6A demethylases fat mass and obesity-associated protein(FTO),AlkB homolog 5(ALKBH5)and ALKBH3 regulate the progression of gastric cancer through various mechanisms,which is closely related to the occurrence and development of gastric cancer.These m6A demethylases regulate the signaling pathway,alter the proliferation and invasion ability of gastric cancer cells,affect its resistance to chemotherapy drugs,participate in regulating the immune response and mitochondrial metabolism of gastric cancer,and affect the growth of gastric cancer cells.They are expected to become a novel therapeutic target.This article comprehensively summarizes the molecular mechanism of m6A demethylase involved in the occurrence and development of gastric cancer,and the relationship between its expression and function,and biological characteristics of m6A demethylase were reviewed,aiming to provide new research ideas for early diagnosis and targeted treatment of gastric cancer.
ABSTRACT
N6-Methyladenosine (m6A) is the most abundant internal modification in eukaryotic mRNA, playing critical role in various bioprocesses. Like other epigenetic modifications, m6A modification can be catalyzed by the methyltransferase complex and erased dynamically to maintain cells homeostasis. Up to now, only two m6A demethylases have been reported, fat mass and obesity-associated protein (FTO) and alkylation protein AlkB homolog 5 (ALKBH5), involving in a wide range of mRNA biological progress, including mRNA shearing, export, metabolism and stability. Furthermore, they participate in many significantly biological signaling pathway, and contribute to the progress and development of cancer along with other diseases. In this review, we focus on the studies about structure, inhibitors development and biological function of FTO and ALKBH5.
ABSTRACT
Objective @#To investigate the role of N-methyladenosine(m6 A) demethylase ALKBH5 in the prolifera- tion and activation of cardiac fibroblasts( CFs) in rats．@*Methods @#The CFs taken from SD rats in 1 to 3 days were isolated by differential adhesion and observed under microscope．After cells were adherently grown to appropriate density，the cells were induced by TGF-β1 for modeling．The model cells were divided into the overexpression of ALKBH5 group infected by lentivirus and the negative control group for 24－48 hours. RT-qPCR was used to detect mRNA expression of ALKBH5，α-smooth muscle actin( α-SMA) ，type I collagen ( Collagen Ⅰ ) and proliferating cell nuclear antigen (PCNA) ．The expression of ALKBH5、α-SMA、Collagen Ⅰ and PCNA were assayed by West- ern blot．The cell proliferation activity was tested by CCK-8 assay and EdU. @*Results @#Compared with the control group，the protein and mRNA of ALKBH5 were reduced in the model group active by TGF-β1．Meanwhile，the bi- omarkers of activation，such as PCNA，α-SMA and Collagen Ⅰ , increased significantly．Besides，the protein and mRNA of PCNA、α-SMA and Collagen Ⅰ were lower in overexpression of ALKBH5 group than those of the negative control group．CCK-8 assay and EdU suggested that the proliferation viability of CFs was reduced evidently in over- expression of ALKBH5 group，compared with the negative control group．@*Conclusion @#Overexpression of ALKBH5 can inhibit the proliferation of CFs，suggesting that ALKBH5 may be a key regulatory point in the development of myocardial fibrosis.
ABSTRACT
OBJECTIVE@#To investigate the effects of ALKBH5 on migration, invasion and epithelial-mesenchymal transition (EMT) of human trophoblast cells.@*METHODS@#The expression plasmid of ALKBH5 or a negative control plasmid (ALKBH5-NC) was transfected in human trophoblast HTR-8 /SVneo cells, and the expressions of ALKBH5 mRNA and protein were detected by qRT-PCR and Western blotting. Transwell assay was used to assess the changes in migration and invasion abilities of the trophoblast cells after the transfection. Western blotting was performed to detect the expressions of EMT-related proteins in the cells including vimentin, fibronectin, E-cadherin, N-cadherin, MMP9 and MMP2.@*RESULTS@#ALKBH5 mRNA and protein expressions were significantly higher in ALKBH5 group than in the control group (@*CONCLUSIONS@#ALKBH5 is involved in the pathogenesis of preeclampsia by inhibiting EMT of trophoblast cells and hence reducing their migration and invasion abilities.
Subject(s)
Female , Humans , Pregnancy , AlkB Homolog 5, RNA Demethylase , Cell Line, Tumor , Cell Movement , Epithelial-Mesenchymal Transition , Pre-Eclampsia , Trophoblasts , Vimentin/geneticsABSTRACT
Objective To investigate the effect of AlkB homologue 5 ( ALKBH5 ) on proliferation, cell cycle, and apoptosis of HepG2 and L-02 cells.Methods Recombinant plasmid vector containing the CDS region of ALKBH5 (pEGFP-C1b-ALKBH5) was stably transfected into HepG2 and L-02 cells.Western blotting was used to detect the expression of green fluonescence protein ( GFP )-ALKBH5.There were two groups in our experiment: GFP-ALKBH5 lentivirus group and GFP lentivirus group.Characteristics, such as proliferation, cell cycle and apoptosis of HepG2 and L-02,were detected through Cell Counting Kit-8 (CCK-8) assay, flow cytometry and clone formation, respectively.Results The result of Western blotting revealed that ALKBH5 was efficiently up-regulated at protein levels.Despite apoptosis, phenotypic analysis revealed that the proliferation and cell phases were significantly inhibited in ALKBH5 overexpressed stable cell strains compared with the control cells (both P<0.05).Conclusion ALKBH5 can restrain fetal liver cell (L-02) and hepatocellular carcinoma cell (HepG2) from proliferating.Taken together, our results strongly suggest that ALKBH5 can play a key role in the generation and progression in HCC as a tumor suppressor.