Viability of different tumor cell lines after treatment with complexes of oligoribonucleotides with D-mannitol

Aim. Studies on the murine B16 melanoma animal model have shown that solid tumor formation was not observed with the simultaneous administration of melanoma cells and complexes of oligoribonucleotides with D-mannitol (ORNs-D-m). The aim of this work was to study the effect of ORNs-D-m and similar compounds on the viability of different tumor cell lines.

Materials and methods. Murine B16 melanoma and human U251 glioblastoma were investigated. Oligoribonucleotides (ORNs), ORNs-D-m (both in the acid form), and their sodium salts were applied for the treatment. The growth inhibition of tumor cells was assessed with methyl thiazolyl tetrazolium (MTT). A comparison of the effect of compounds was carried out by the concentration of half-maximal inhibition of IC50.

Results. The duration and dose of ORNs-D-m treatment effects on B16 viability. Thus, the IC₅₀ after 48-hours treatment was equal to 2.7 ± 0.2 mg/ml, while with ORNs treatment, IC₅₀ was in the range of 6.9 ± 0.4 mg/ml. For the U251 cell line, a similar trend in viability after treatment was found, with IC₅₀ for ORNs-D-m – 1.2 ± 0.04 mg/ml, for ORNs - 10.1 ± 0.2 mg/ml. For comparison, salt forms either showed no inhibitory effect on B16 or influenced at significantly higher concentrations compared to acid forms on U251.

Conclusions. ORNs-D-m inhibits the viability of B16 and U251 tumor cell lines. ORNs have a less inhibitory effect on viability. The acid form of ORNs-D-m has a more apparent effect on cell viability compared to the salt form.