O. V. Skachkova¹*, O. I. Gorbach¹, M. V. Inomistova¹,
L. V. Garmanchuk², N. M. Khranovska¹

¹National Cancer Institute, Kyiv, Ukraine;
²ESC “Institute of Biology and Medicine”, Taras Shevchenko National University of Kyiv, Ukraine;
*e-mail: oksanaskachkova@ukr.net

Received: 20 June 2020; Accepted: 17 December 2020

Cancer stem cells (CSCs) play an important role in resistance to cancer treatment and recurrence developing. The aim of this study was to obtain cell culture of MOR line non-small cell lung cancer cells enriched in CSCs and to investigate its functional and molecular-genetic properties. Tumor spheroids (TS) of MOR cell line were generated in vitro under normal adhesive (0.2% carboxymethyl cellulose, CMC) or low-adhesive (2% agarose) culture conditions. Lateral population of TS was evaluated by flow cytometry with the use of R-123 fluorescent dye, the index of R-123 exclusion was also assessed. Expression of CD44, ALDHA1, CD133, Sox2 and Nanog mRNA was determined with RT-qPCR. It was found that regardless of the culture conditions tumor spheroids form a lateral population characterized by an increased dye exclusion index. Expression levels of CD44, ALDHA1, CD133, Sox2 and Nanog mRNA in TS cells obtained under low-adhesive (2% agarose) conditions were significantly higher than in monolayer cells and cells obtained using 0.2% CMC. Thus, the proposed method of culturing in low-adhesive conditions allowed to enrich significantly tumor spheroids of MOR line in  cells with CSC properties.