Recombinant Analogue of the Human Protein SLURP-1 Inhibits the Growth of U251 MG and A172 Glioma Cells.

The alpha7 nicotinic acetylcholine receptor (α7-nAChR) is considered a promising pharmacological target for the carcinoma therapy. We have previously shown that the recombinant analogue of the human protein SLURP-1 (rSLURP-1) effectively inhibits the growth of carcinomas of various origins via the interaction with α7-nAChR and down-regulation of expression of this receptor. Expression of α7-nAChR is increased in gliomas compared to healthy human brain tissues; however, the role of this receptor in the gliomas development is poorly understood. It was shown for the first time that rSLURP-1 significantly inhibits the growth of glioma model cells U251 MG and A172 up to ∼70%, which is comparable with the effect of α-bungarotoxin, a selective α7-nAChR inhibitor. The half-maximum effective concentrations of rSLURP-1 for U251 MG and A172 cells were 2.82 ± 0.2 and 8.9 ± 0.3 nM, respectively. Coincubation of U251 MG cells with rSLURP-1 and the nAChR inhibitor mecamylamine attenuates the antiproliferative activity of rSLURP-1, indicating nAChR as a molecular target for the rSLURP-1 action in gliomas.