CAJ | 학술논문

目的观察非p53依赖途径突变型(T58A)与野生型c-myc(WT)对乳腺癌细胞p21Cipl基因调控及细胞凋亡的影响.方法携带c-myc T58A与WT基因慢病毒表达载体分别感染乳腺癌细胞株HCC1937(细胞感染率为85％),未感染者及仅感染慢病毒者为A组(空白对照组)、B组(感染对照组),感染c-myc T58A及WT者为实验组C、D组.慢病毒p21Cip1/siRNA载体感染以上各组细胞,逆转录-聚合酶链反应(RT-PCR)和 Westemblot检测感染前后各组c-myc、p21Cipl的mRNA和蛋白表达,原位末端转移酶标记(TUNEL)检测细胞凋亡.结果与A、B组比较,C组和D组c-myc过表达(P＜0.001).感染前,C组p21Cip1含量显著高于A、B、D组(P＜0.001),D组p21Cipl含量最低(P＜0.01),C组细胞凋亡率显著低于A、B、D组,D组凋亡率最高,凋亡率:A组为(5.5±0.5)％、B组为(5.8±0.3)％、C组为(2.8±0.3)％、D组为(9.8±0.8)％(P＜0.01)；感染后,各自组内凋亡率较前明显提高(P＜0.05).结论非p53依赖途径中,野生型c-myc可通过下调p21Cipl基因表达促进细胞凋亡,突变后(T58A)此功能减弱,诱导细胞凋亡能力降低.
목적 관찰비p53의뢰도경돌변형(T58A)여야생형c-myc(WT)대유선암세포p21Cipl기인조공급세포조망적영향.방법 휴대c-myc T58A여WT기인만병독표체재체분별감염유선암세포주HCC1937(세포감염솔위85％),미감염자급부감염만병독자위A조(공백대조조)、B조(감염대조조),감염c-myc T58A급WT자위실험조C、D조.만병독p21Cip1/siRNA재체감염이상각조세포,역전록-취합매련반응(RT-PCR)화 Westemblot검측감염전후각조c-myc、p21Cipl적mRNA화단백표체,원위말단전이매표기(TUNEL)검측세포조망.결과 여A、B조비교,C조화D조c-myc과표체(P＜0.001).감염전,C조p21Cip1함량현저고우A、B、D조(P＜0.001),D조p21Cipl함량최저(P＜0.01),C조세포조망솔현저저우A、B、D조,D조조망솔최고,조망솔:A조위(5.5±0.5)％、B조위(5.8±0.3)％、C조위(2.8±0.3)％、D조위(9.8±0.8)％(P＜0.01)；감염후,각자조내조망솔교전명현제고(P＜0.05).결론 비p53의뢰도경중,야생형c-myc가통과하조p21Cipl기인표체촉진세포조망,돌변후(T58A)차공능감약,유도세포조망능력강저.
Objective To investigate the effect of mutant (T58A) and wild type (WT) c-myc on p21Cipl and apoptosis of breast cancer cells in a p53-independent way.Methods Lentiviral vectors containing c-myc T58A and WT were transfected into breast cancer cells HCC1937 (cell transfection rate exceeds 85％).Untreated cells (group A) and cells transfected by lentivirus without c-myc gene (group B) served as blank control group and transfection control group respectively.Cells stably expressing c-myc T58A (group C) and WT (group D) served as experiment groups.All the cells were then transfected by p21Cipl/ siRNA.RT-PCR and Western blotting were used to detect the mRNA and protein levels of c-myc and p21Cipl,and the apoptosis was examined by using TdT-mediated dUTP nick end labeling (TUNEL).Results As compared with groups A and B,the c-myc was overexpressed in groups C and D (all P ＜0.01).Before transfection,the p21 Cipl in group C was highest (P ＜ 0.01),while group D had the lowest expression of p21Cipl (P ＜0.01) ; the apoptosis rate in group C was lower than in other groups,and that in group D was the highest:(5.5 ± 0.5) ％,(5.8 ± 0.3) ％,(2.8 ± 0.3) ％ and (9.8 ± 0.8) ％ in groups A,B,C and D,respectively (P ＜0.01).After transfection,the apoptosis rate in all groups were improved obviously (P ＜ 0.05).Conclusion Normally,in a non-p53 background,c-myc WT can suppress the expression of p21Cipl,resulting in the increased apoptosis rate,but after mutation (T58A),the ability of c-myc to induce apoptosis is decreased.