Plasma ‐activated medium (PAM) kills human cancer‐initiating cells

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.
Source: Pathology International - Category: Pathology Authors: Tags: Original Article Source Type: research