基于系统发育与模拟mRNA结构设计的靶向蛋白激酶C-α的反义药物

目的:系统发育比较分析与二级结构模拟结合用于反义药物优化设计。方法:靶向自由能低的完全保守区域设计反义脱氧寡核苷酸(ODN)。体外评价ODN对人A549细胞和鼠B16-BL6细胞的增殖抑制效应。细胞原位杂交与RT-PCR方法检测靶mRNA表达。用裸鼠荷A549肿瘤和小鼠荷B16肿瘤模型评价ODN的体内活性。结果:3个ODN体外对A549细胞的IC_(50)值显著低于阳性对照ISIS3521。效果最佳的ODN AP1261可剂量依赖地抑制PKC-α mRNA的表达。AP1261在0.005-0.5mg·kg~(-1)·d~(-1)的剂量范围内可抑制A549和B16肿瘤的体内生长。相同剂量下AP1261对A549肿瘤体内生长的抑制率显著高于ISIS3521,而ISIS3521对鼠B16肿瘤的体内外生长无影响。结论:AP1261可能成为有效的抗癌药物或佐剂,系统发育比较分析与二级结构模拟相结合有助于反义药物设计。

Antisense candidates against protein kinase C-alpha designed based on phylogenesis and simulant structure of mRNA

AIM: To optimize the antisense drug design by the combined method of phylogenetic analysis and secondary structure prediction and to get ideal candidates. METHODS: The phylogenetic analysis and the secondary structure simulation were performed by computer. Oligodeoxynucleotides (ODN) were designed against the full-conserved blocks with low local reaction free energy of protein kinase C (PKC)-alpha mRNA. The in vitro effects of ODN were evaluated by human A549 lung carcinoma cells and mouse B16-BL6 melanoma cells, the expression of target mRNA was detected by in situ hybridization and RT-PCR. The in vivo effects of ODN were also evaluated by models of A549 xenografts in nude mice and B16 melanoma in mice. RESULTS: Three ODN had significantly lower IC50 values than that of ISIS3521, the positive control, on A549 cells in vitro. Five ODN inhibited the growth of B16-BL6 cells with IC50 <100 nmol/L, while IC50 of ISIS3521 was >200 nmol/L. In situ hybridization and RT-PCR showed that the best candidate AP1261 inhibited the expression of PKC-alpha at mRNA level in a dose-dependent manner. AP1261 inhibited the growth of A549 and B16 tumors in vivo at 0.005-0.5 mg.kg(-1).d(-1). The inhibitory rate of AP1261 on A549 tumors was greater than that of ISIS3521 at the same dose. ISIS3521 did not affect the growth of B16 tumors. CONCLUSION: AP1261 may be of value as an antitumor agent or adjuvant and the combined method of phylogenetic analysis and secondary structure prediction is a potential helpful tool for antisense drug design.