The effect of hydrogen gas on the behavior of gastric cancer cellsCercetare Științifică
Hydrogen inhibits the proliferation and migration of gastric cancer cells by modulating lncRNA MALAT1/miR-124-3p/EZH2 axis
https://doi.org/10.1186/s12935-020-01743-5
Abstract
Background
Gastric cancer is one of the most prevalent and deadly malignancies without efficient treatment option. This study aimed to investigate the effect of hydrogen gas on the behavior of gastric cancer cells.
Methods
Gastric cancer cell lines MGC-803 and BGC-823 were treated with or without H2 /O2 gas mixture (66.7%:33.3% v/v). Proliferation and migration were assessed by MTT and scratch wound healing assays respectively. The expression of lncRNA MALAT1, miR-124-3p, and EZH2 was analyzed by real-time quantitative PCR and/or western blot. Tumor growth was estimated using xenograft mouse model.
Results
H2 gas significantly inhibited gastric tumor growth in vivo and the proliferation, migration, and lncRNA MALAT1 and EZH2 expression of gastric cancer cells while upregulated miR-124-3p expression. LncRNA MALAT1 overexpression abolished all the aforementioned effects of H2. LncRNA MALAT1 and miR-124-3p reciprocally inhibited the expression of each other. MiR-124-3p mimics abrogated lncRNA MALAT1 promoted EZH2 expression and gastric cancer cell proliferation and migration.
Conclusions
These data demonstrated that H2 might be developed as a therapeutics of gastric cancer and lncRNA MALAT1/miR-124-3p/EZH2 axis could be a target for intervention.
Background
Gastric cancer is the sixth most-common cancer with over a million new cases worldwide in 2018 and causes second most mortalities among malignancies [1]. While Helicobacter pylori infection is the most prominent cause of gastric cancer, many nutritional and life style factors, such as drinking, smoking, physical activity, overweight, intake of fruit and vegetable, are also significantly associated with the development of gastric cancer [2]. Genetically, the main oncogene of gastric cancer is CDH1 (E-cadherin) as many pathogenic variants are associated with familial diffuse-type gastric cancer [3, 4]. However, many other genes including MSH2, PMS2,, BRCA1, PALB2, CTNNA1, and ATM, have been identified to increase the risk of gastric cancer [5,6,7,8,9,10,11,12].
Long noncoding RNAs (lncRNAs) are transcripts larger than 200 base-pairs and similar to mRNA biochemically and structurally but do not code for protein [13]. A large number of lncRNA have been implicated in different aspects of cancer biology [14]. LncRNA MALAT1 (metastasis associated lung adenocarcinoma transcript 1) has been shown to promote the proliferation and migration of cancer cells, epithelial-mesenchymal transition, and metastasis of many cancer types but recently found to function as a tumor suppressor in breast and colorectal cancers [16]. LncRNA MALAT1 enhanced the stemness, proliferation, migration, invasion, and drug resistance of gastric cancer cells [17,18,19,20].
Although hydrogen gas was found effective in treating mouse squamous cell carcinoma and thought it might be used to treat other cancer [21], its clinical application was not widely explored until 2007 Ohsawa et al. demonstrated that hydrogen gas selectively eliminated the hydroxyl radical and attenuated focal ischemia and reperfusion caused oxidative stress and brain injury [22]. Increasing evidence showed the potential of hydrogen gas in preventing and relieving different cancers [23]. Drinking hydrogen-rich water for 6 weeks reduced reactive oxygen metabolites in the blood, maintained blood oxidation potential, improved the quality of life of malignant liver cancer patients after radiotherapy [24]. Daily inhalation of hydrogen for 3 month resulted in the shrinkage of metastatic gallbladder cancer and improve of quality of life [25]. This study aims to explore the effects of hydrogen gas on gastric cancer cells and the underlying molecular mechanism.
Materials and methods
Cell culture
Human gastric cancer cell lines MGC-803 and BGC-823 were purchased from the Type Culture Collection of the Chinese Academy of Sciences (Shanghai, China). Cells were cultured at 37 °C and 5% CO2 in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 100 U/ml of penicillin and 100 µg/ml of streptomycin (All from ThermoFisher, (Shanghai, China).
Hydrogen/oxygen gas mixture (66.7%:33.3% v/v) was produced with a Hydrogen/Oxygen Generator (Asclepius Meditec, Shanghai, China). Hydrogen treatment was executed in an adjustable three gas cell culture incubator (Puhe Bio, Wuxi, China). MALAT1 overexpression vector (GenScript, Nanjing, China) and miR-124-3p mimics (GeneCopoeia, Guangzhou, China) were transfected using Lipofectamine 3000 (ThermoFisher, Shanghai, China).
Hydrogen inhibits the proliferation and migration of gastric cancer cells by modulating lncRNA MALAT1/miR-124-3p/EZH2 axis
Cancer Cell International volume 21, Article number: 70 (2021)