RRC ID 59932
Author Zhang B, Zhang X, Jin M, Hu L, Zang M, Qiu W, Wang S, Liu B, Liu S, Guo D.
Title CagA increases DNA methylation and decreases PTEN expression in human gastric cancer.
Journal Mol Med Rep
Abstract Gastric cancer is one of the leading causes of cancer-associated mortality worldwide. Cytotoxin‑associated gene A (CagA) has been reported to be associated with gastric diseases. Phosphatase and tensin homolog (PTEN) and tet methylcytosine dioxygenase 1 (Tet1) are important tumor‑suppressor genes. The present study aimed to investigate the underlying functions of CagA in human gastric cancer, and to explore the associations between CagA, PTEN and Tet1 in gastric cancer. For that purpose, CagA overexpression and Tet1 interference recombinant lentiviral plasmids were constructed. Quantitative polymerase chain reaction (qPCR) was utilized to screen gene expression in HGC‑27 human gastric cancer cells overexpressing CagA. qPCR and western blotting were used to detect gene and protein expression, respectively. In addition, the methylation status of PTEN was detected by methylation‑specific PCR. The expression levels of PTEN, Tet1, apolipoprotein B mRNA editing enzyme catalytic subunit (APOBEC)3A, APOBEC3C and APOBEC3F were significantly decreased in the CagA overexpression group compared with in the negative control group in HGC‑27 cells. Compared with in the negative control group, the mRNA and protein expression levels of PTEN were markedly decreased in cells with Tet1 interference. The decreased expression of PTEN was associated with increased methylation levels in the cells. In addition, the protein expression levels of PTEN were significantly decreased in HGC‑27 cells when CagA was overexpressed. The expression levels of PTEN and Tet1 were also markedly decreased in CagA+ gastric cancer tissues compared with in non‑cancerous tissues. The decreased expression of PTEN in CagA+ gastric cancer tissues was associated with increased methylation levels. In conclusion, overexpression of CagA significantly decreased the expression of PTEN, Tet1, APOBEC3A, APOBEC3C and APOBEC3F in human gastric cancer. In addition, CagA increased DNA methylation and decreased PTEN expression, which was reversed by Tet1 overexpression. The present study may facilitate future therapeutic approaches targeting human gastric cancer.
Volume 19(1)
Pages 309-319
Published 2019-1-1
DOI 10.3892/mmr.2018.9654
PMID 30431097
PMC PMC6297774
MeSH Antigens, Bacterial / genetics Antigens, Bacterial / metabolism* Bacterial Proteins / genetics Bacterial Proteins / metabolism* CpG Islands Cytotoxins / metabolism DNA Methylation* Gene Expression Regulation, Neoplastic* Humans Mixed Function Oxygenases / genetics Mixed Function Oxygenases / metabolism* PTEN Phosphohydrolase / genetics PTEN Phosphohydrolase / metabolism* Promoter Regions, Genetic Proto-Oncogene Proteins / genetics Proto-Oncogene Proteins / metabolism* Stomach Neoplasms / genetics* Stomach Neoplasms / metabolism Stomach Neoplasms / pathology Tumor Cells, Cultured
IF 1.851
Times Cited 5
Human and Animal Cells HGC-27(RCB0500)