【摘要】 目的研究第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)突变对人鼻咽癌细胞系CNE-1中蛋白激酶B(Akt)的磷酸化的影响。方法 CNE-1细胞用含100 m L/L胎牛血清RPMI1640培养基培养,并分别转染野生型PTEN(wt PTEN)质粒、突变型PTEN C124S质粒和突变型PTEN G129E质粒。各组细胞加刺激前用无血清RPMI1640培养基饥饿过夜,用0.15 IU/m L胰岛素或0.3μg/m L重组人表皮生长因子(rh EGF)刺激,Western blot法检测Akt的磷酸化水平。结果胰岛素和rh EGF刺激均可导致CNE-1细胞Akt信号激活;wt PTEN可抑制胰岛素或rh EGF刺激引起的Akt信号激活;PTEN C124S突变体可激活胰岛素刺激引起的Akt信号,但不可激活rh EGF刺激引起的Akt信号;PTEN G129E突变体抑制胰岛素刺激引起的Akt信号激活。结论 wt PTEN可抑制胰岛素或rh EGF刺激引起的Akt信号激活,但PTEN C124S和G129E突变体不能一致性激活Akt信号表达。这表明PTEN基因突变可能与Akt信号表达无关。更多还原

【Abstract】 Objective To study the effect of phosphatase and tensin homolog deleted on chromosome 10( PTEN) mutations on protein kinase B( Akt) phosphorylation of CNE-1 nasopharyngeal carcinoma cell line. Methods CNE-1 cells were cultured in RPMI1640 medium containing 100 m L / L fetal calf serum,and then transfected with wild-type PTEN( wt PTEN),mutant PTEN C124 S and mutant PTEN G129 E plasmid separately. After overnight serum starvation,the cel s were stimulated with 0. 15 IU / m L insulin or 0. 3 μg / m L recombinant human epidermal growth factor( rh EGF). At last,Akt phosphorylation was evaluated by Western blotting. Results Insulin or rh EGF stimulation led to Akt activation in CNE-1 cel s. The wt PTEN inhibited insulin- or rh EGF-stimulated phosphorylation of Akt. PTEN C124 S mutant activated insulin-stimulated phosphorylation of Akt,but not rh EGF-stimulated phosphorylation of Akt. PTEN G129 E mutant inhibited insulin-stimulated phosphorylation of Akt. Conclusion The wt PTEN inhibited insulin- or rh EGF-stimulated phosphorylation of Akt,while PTEN C124 S and G129 E mutants failed to activate the phosphorylation of Akt consistently. This suggested PTEN mutations might not be correlated with activated Akt.更多还原