Aurora-A/NF-κB is involved in the radioresistance of human lung adenocarcinoma SPC-A1/DTX cells / 医学研究生学报

ABSTRACT

Objective Human lung adenocarcinoma SPC-A1/DTX cells have a higher radioresistance than SPC -A1cells. This study was to investigate the role of Aurora-An/uclear factor κB ( NF-κB) in the radioresistance of human lung adenocarcinoma SPC-A1/DTX cells and its possible molecular mechanisms . Metho ds We collected human lung adenocarcinoma SPC-A1 and SPC A1/DTX cells and divided them into four groupssh-Aurora-A ( Aurora-A plasmid interference ) , sh-NC, NF-κB inhibition ( SPC-A1/DTX +NF-κB inhibitor ) , and DMSO control .We measured the in vitro radio-sensitivity of the cells by MTT assay , determined their proliferation ability by cloning assay , and detected the mRNA and protein expressions of the target genes by real -time quantitative RT-PCR and Western blot , respectively . Results The 50% effective doses ( ED50 ) of the SPC-A1 and SPC-A1/DTX cells on radiotherapy were (6.5 ±0.3) and (12.8 ±0.6) Gy, respectively, with statisti-cally significant difference between the two groups ( P <0.01 ) .In the radiation doses of 0, 2, 4, and 6 Gy, the numbers of the cloned SPC-A1 cells were 345 ±20 , 252 ±22 , 170 ±15 , and 81 ±10 , sig-nificantly lower than those of the cloned SPC -A1/DTX cells (402 ±21, 370 ±18, 301 ±16, and 252 ±15) (P<0.05).The protein and mRNA expressions of Aurora-A were remarkably higher in the SPC-A1/DTX than in the SPC-A1 cells (1.00 ±0.08 and 1.00 ±0. 06 vs 0.49 ±0.03 and 0.22 ±0.02, P<0.05).MTT assay showed a higher ED50 in the sh-NC than in the sh-Aurora-A cells ([11. 8 ±0.5] vs [7.1 ±0.3] Gy, P<0.01) as well as in the control than in the NF-κB inhibition group ([11.7 ±0.5] vs [6.1 ±0.3] Gy, P<0.01).Inhibition of Aurora-A increased the expression of IκBa by 2.18 ±0.32 times (P<0.01) and that of NF-κB by 0.24 ±0.03 times (P<0.01).The expressions of IκBa (1.00 ±0.05) and NF-κB (1.00 ±0.04) were significantly lower in the parent strains of SPC-A1 than 0.65 ±0.04 and 2.18 ±0.15 in the drug-resistant strains of SPC-A1/DTX (P<0.01). Conclusi on Auro-ra-A/NF-κB is involved in the radioresistance of human lung adenocarcinoma SPC-A1/DTX cells.