吉非替尼通过靶向circ-0000745/miR-421轴调控胃癌细胞N87增殖、凋亡的分子机制

目的:探讨吉非替尼是否通过环状RNA(circRNA)circ-0000745/微小RNA-421(miR-421)轴调控胃癌细胞N87增殖、凋亡。方法:运用细胞计数试剂盒8(CCK-8)、平板克隆实验、蛋白印迹(Western blot)分析、流式细胞术与定量逆转录聚合酶链反应(qRT-PCR)测定空白对照(NC)组、0.125,0.25,0.5μmoL·L^(-1)吉非替尼组、si-NC组、si-circ-0000745组、NC+si-NC组、吉非替尼+si-NC组、吉非替尼+si-circ-0000745组、si-NC+anti-miR-NC组、si-circ-0000745+anti-miR-NC组、si-circ-0000745+anti-miR-421组胃癌细胞N87的活力、克隆形成、细胞周期蛋白D1(CyclinD1)、P21、B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2相关X蛋白(Bax)表达、凋亡率与circ-0000745、miR-421表达。双荧光素酶实验分析circ-0000745与miR-421间的关系。结果:与NC组相比,0.125,0.25,0.5μmol·L^(-1)吉非替尼组细胞活力、克隆形成数、CyclinD1、Bcl-2蛋白表达量、miR-421表达量逐渐降低,而P21蛋白表达量、凋亡率、Bax蛋白表达量、circ-0000745表达量逐渐增加,且不同剂量组差异有统计学意义(P<0.05)。circ-0000745靶向负调控miR-421。与si-NC组相比,si-circ-0000745组胃癌细胞N87活力、克隆形成数、CyclinD1、Bcl-2蛋白表达量升高,P21蛋白表达量、凋亡率和Bax蛋白表达量降低,差异有统计学意义(P<0.05)。与吉非替尼+si-NC组相比,吉非替尼+si-circ-0000745组N87细胞中活力、克隆形成数、CyclinD1、Bcl-2蛋白表达量增加,P21、Bax蛋白表达量、凋亡率减少,差异均有统计学意义(P<0.05)。与si-circ-0000745+anti-miR-NC组相比,si-circ-0000745+anti-miR-421组N87细胞活力、克隆形成数、CyclinD1、Bcl-2蛋白表达量降低,P21、Bax蛋白表达量、凋亡率升高,差异有统计学意义(P<0.05)。结论:吉非替尼通过上调circ-0000745靶向miR-421,抑制胃癌细胞N87增殖,并诱导其凋亡。

Biotransformation of malabaricone C by rat hepatic microsomes and cytotoxic activities against gastric cancer cells in vitro

Malabaricone C （1）, isolated from the seeds ofMyristicafragrans Houtt., belongs to a kind of diarylnonanoid compounds that are only found in Myristicaceae till now. In this study, biotransformation of 1 was investigated using rat hepatic microsomes for the first time and the main biotransformation product was elucidated as malabaricone B （2） according to the spectroscopic data. Further evaluation on human gastric cancer cell lines showed that the cytotoxic effects of malabaricone C and its metabolite malabaricone B were comparable to those of vinorelbine, with the values of IC50 of （42.62±3.10） and （19.80±1.70） μg/mL on NCI-N87, and （22.94±1.33） and （19.60±2.21） μg/mL on MGC803, respectively. Statistical analysis revealed that malabaricone B had significantly stronger cytotoxicity than the parent compound （P〈0.01 on NCI-N87 and P〈0.05 on MGC803）, which may indicate a bioactivation of malabaricone C by hepatic microsomes. These results suggest that malabaricone C has a simple biotransformation pathway by hepatic microsomes and provide valuable information for further investigation on both the parent compound and its biotransformation product as anti-gastric cancer agents or lead compounds.