Abstract
Cancer stem cells (CSCs), a subgroup of cancer cells, have self-renewal capacity and differentiation potential and drive tumor growth. CSCs are highly-resistant to conventional chemo-radio therapy. Phytochemicals were shown to be able to eliminate CSCs. Phytol is a diterpene alcohol with demonstrated anticancer effects. The current study compared the effect of phytol with retinoic acid (RA) as a well-known inducers of CSC differentiation and cisplatin, a common chemotherapy drug, on CSC markers in human embryonic carcinoma NCCIT cells. NCCIT cells were exposed to 10 mM RA for 14 day to induce differentiation. Moreover, NCCIT cells were treated with IC50 dose of cisplatin (12 µM) and phytol (40 µM) for 7 day. Real-time PCR showed that phytol was more effective that RA and cisplatin in down-regulating the CSC markers OCT4, NANOG, SOX2, ALDH1, ABCB1, CD44 and CD133. Percentage of SP (13%) and ABCB1+ (0.34%) in NCCIT cells decreased to 7% and 0.1% respectively after treatment with phytol. A very small proportion of NCCIT cells were positive for CD44 (0.2%) and CD133 (0.48%) and this fraction did not change significantly after treatment with three agents. In conclusion, phytol has the greatest inhibitory effect on CSC population and markers than RA and cisplatin.
Acknowledgments
The authors thank Vice Chancellor for Research and Technology, Shahid Bahonar University of Kerman, Kerman, Iran for financial support
Disclosure statement
The authors declare that they have no conflict of interest.
Ethical Approval
This article does not contain any studies with human participants or animals performed by any of the authors.