Plasma-activated medium (PAM) kills human cancer-initiating cells.

Abstract

Medical non-thermal plasma (NTP) treatments for various types of cancers have been reported. Cells with tumorigenic potential (cancer-initiating cells; CICs) are few in number in many types of tumors. CICs efficiently eliminate anti-cancer chemicals and exhibit high-level aldehyde dehydrogenase (ALDH) activity. We previously examined the effects of direct irradiation via NTP on cancer cells; even though we targeted CICs expressing high levels of ALDH, such treatment affected both non-CICs and CICs. Recent studies have shown that plasma-activated medium (PAM) (culture medium irradiated by NTP) selectively induces apoptotic death of cancer but not normal cells. Therefore, we explored the anti-cancer effects of PAM on CICs among endometrioid carcinoma and gastric cancer cells. PAM reduced the viability of cells expressing both low and high levels of ALDH. Combined PAM/cisplatin appeared to kill cancer cells more efficiently than did PAM or cisplatin alone. In a mouse tumor xenograft model, PAM exerted an anti-cancer effect on CICs. Thus, our results suggest that PAM effectively kills both non-CICs and CICs, as does NTP. Therefore, PAM may be a useful new anti-cancer therapy, targeting various cancer cells including CICs.

• Authors: Jun-Ichiro Ikeda, Hiromasa Tanaka, Kenji Ishikawa, Hajime Sakakita, Yuzuru Ikehara, Masaru Hori
• Journal: Pathology international (Pathol Int) Vol. 68 Issue 1 Pg. 23-30 (Jan 2018) ISSN: 1440-1827 [Electronic] Australia
• PMID: 29235204 (Publication Type: Journal Article)
• Copyright: © 2017 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

Chemical References

• Culture Media, Conditioned
• Plasma Gases

Topics

• Animals
• Cell Line, Tumor
• Culture Media, Conditioned (pharmacology)
• Humans
• Mice
• Neoplastic Stem Cells (drug effects)
• Plasma Gases (pharmacology)
• Xenograft Model Antitumor Assays