Targeted competitive binding miR-20b lncRNA MEG3 and application thereof in ionizing radiation

The invention belongs to the technical field of medicines, and discloses an lncRNA MEG3 (long non-coding ribonucleic acid) competitively combined with miR-20b in a targeting manner and application of the lncRNA MEG3. The nucleotide sequences of MEG3, miR-20b and BNIP2 are respectively as shown in SEQ ID No. 1, SEQ ID No. 2 and SEQ ID No. 3. According to the invention, within 24 hours in an early stage after radiation, expression of MEG3 is reduced, expression of miR-20b is increased and expression of BNIP2 is reduced, which indicates that cells are in a radiation damage self-protection stage; the target action relationship between the lncRNA MEG3 and the miR-20b and the target action relationship between the miR-20b and the BNIP2 are confirmed; the influence of MEG3 on cell viability and cell apoptosis after radiation damage is confirmed; meanwhile, MEG3 is used as a new radiation damage marker, and overexpression of MEG3 can reduce cell survival, reduce cell viability and increase cell radiation damage; by i