Hydrogen Silica Shows Promise Against Esophageal Cancer Cells
- Authors
- Yoshiharu Tanaka, Qiang Li, Nobuhiko Miwa
- Journal
- Medical Gas Research
- Year
- 2017
- DOI
- 10.4103/2045-9912.208510
- Study Type
- Cell Culture
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- Japan
- Health Condition
- Esophageal Squamous Cell Carcinoma
- Body System
- Digestive System
TL;DR
A special form of silica that releases hydrogen was found to inhibit the growth and spread of human esophageal cancer cells without significantly harming normal cells.
Key Finding
Hydrogen-occluding-silica inhibited esophageal cancer cell proliferation and migration while triggering apoptosis (programmed cell death) in a concentration-dependent manner, though the highest doses also showed toxic effects on normal esophageal cells.
Summary
Researchers tested a solid material called hydrogen-occluding-silica (H2-silica) that releases hydrogen gas into cells grown in laboratory dishes. They used two types of human esophageal cells: cancer cells and normal cells. The H2-silica reduced cancer cell growth and movement in a dose-dependent way (meaning higher amounts had stronger effects) and triggered cancer cell death through specific molecular pathways. However, at the highest doses tested, the material also damaged normal esophageal cells.
Practical Takeaway
This is an early laboratory study in cells only, not humans, so it cannot yet inform real-world use. The findings suggest H2-silica may have anti-cancer properties, but the fact that high concentrations harmed normal cells raises safety concerns that would need to be addressed in further research before any clinical application could be considered.
Abstract
In the last decade, many studies have shown that hydrogen gas or hydrogen water can reduce the levels of reactive oxygen species in the living body. Molecular hydrogen has antioxidant and antiapoptotic effects and a preventive effect on oxidative stress-induced cell death. In the present study, we investigated solidified hydrogen-occluding-silica (H2-silica) that can release molecular hydrogen into cell culture medium because the use of hydrogen gas has strict handling limitations in hospital and medical facilities and laboratories, owing to its physicochemical characteristics. Human esophageal squamous cell carcinoma (KYSE-70) cells and normal human esophageal epithelial cells (HEEpiCs) were used to investigate the effects of H2-silica on cell viability and proliferation. Cell migration was examined with wound healing and culture-insert migration assays. The intracellular levels of reactive oxygen species were evaluated with a nitroblue tetrazolium assay. To assess the apoptotic status of the cells, the Bax/Bcl-2 ratio and cleaved caspase-3 were analyzed by western blot. The results showed that KYSE-70 cells and HEEpiCs were generally inhibited by H2-silica administration, and there was a significant proliferation-inhibitory effect in an H2-silica concentration-dependent manner compared with the control group (P < 0.05) in KYSE-70. Apoptosis-inducing effect on KYSE-70 cells was observed in 10, 300, 600, and 1,200 ppm H2-silica, and only 1,200 ppm H2-silica caused a 2.4-fold increase in apoptosis in HEEpiCs compared with the control group as the index of Bax/Bcl-2. H2 silica inhibited cell migration in KYSE-70 cells, and high concentrations had a cytotoxic effect on normal cells. These findings should provide insights into the mechanism of inhibition of H2-silica on human cancer cells in vitro.