RESUMO
@#[摘 要] 目的：探讨程序性死亡受体-1（PD-1）单抗联合顺铂或吉西他滨在KRAS基因突变非小细胞肺癌（NSCLC）A549细胞移植瘤小鼠模型治疗中的作用。方法：构建免疫系统-肿瘤双人源化A549细胞小鼠移植瘤模型，将60只小鼠按随机数字表法分成6组（10只/组），分别为对照组（200 μL/kg PBS）、PD-1单抗组（20 mg/kg PD-1单抗）、顺铂组（3 mg/kg顺铂）、PD-1单抗+顺铂组（20 mg/kg PD-1单抗+3 mg/kg顺铂）、吉西他滨组（30 mg/kg吉西他滨）和PD-1单抗+吉西他滨组（20 mg/kg PD-1单抗+30 mg/kg吉西他滨）。TUNEL和DAPI双染色法检测移植瘤组织中细胞凋亡水平，测量移植瘤体积和质量并计算肿瘤生长抑制率，免疫组化法检测移植瘤微血管密度（MVD）。结果：成功构建免疫系统-肿瘤双人源化NSCLC A549细胞小鼠移植瘤模型，PD-1单抗+顺铂组移植瘤的细胞凋亡率、肿瘤生长抑制率均最高，移植瘤体积、质量和MVD均最小，与其他5组小鼠比较差异均有统计学意义（均P<0.05）。结论：顺铂与PD-1单抗具有协同活性，而吉西他滨拮抗PD-1单抗的治疗作用。提示PD-1单抗联合顺铂对KRAS突变NSCLC A549细胞移植瘤小鼠的疗效更好。
RESUMO
<p><b>OBJECTIVE</b>To explore the mechanism governing the reversal of multidrug resistance in human breast carcinoma cells by chelerythrine.</p><p><b>METHODS</b>Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to determine the expressions of protein kinase Cα (PKCα) and multidrug resistance-related genes ABCG2, ABCC1, MDR1, and P-glycoprotein (P-gp) in MCF-7Taxol cells after treatment with chelerythrine and phorbol-12-myristate-13-acetate (PMA). Also, the antitumor effect of PMA or chelerythrine and effects of PKCα activator or inhibitor in combination with paclitaxel or adriamycin on multidrug resistance in MCF-7Taxol cells were evaluated by MTT.</p><p><b>RESULTS</b>RT-PCR or Western blot showed that the expressions of MDR1 and P-gp were significantly higher in MCF-7Taxol cells exposed to PMA stimuli (both P0.05).</p><p><b>CONCLUSION</b>PKCα inhibitor chelerythrine can reverse multidrug resistance in breast carcinoma cells by inhibiting the expressions of MDR1 and P-gp expression in vitro.</p>