基于lncRNA GAS5和肝素酶双靶向纳米探针的构建及其对胃癌转移诊断的实验研究

Metastasis is the major death cause of gastric cancer. Diagnosis of gastric cancer metastasis has important value for the treatment and prognosis for patients. The molecular beacon technology by targeting specific base sequences can provides a new approach to the accurate diagnosis of gastric cancer metastasis in the nucleic acid level. Databases and our previous study showed that lncRNA GAS5 can be as the diagnostic target of metastasis gastric cancer, it is over-expression in gastric cancer metastasis and closely associated with gastric cancer metastasis. In the early stage, we have constructed a molecular beacon probe with gold nanoparticles as the quenching agent, the molecular beacon probe can target two specific sequences of the lncRNA GAS5 and it has good imaging effect in vitro. It is reported that heparin enzyme is over-expressed in metastatic gastric cancer. In the preliminary stage of the research group, the molecular beacon probe can be enriched to gastric cancer metastasis by the heparin enzyme antibody. In order to ensure the molecular beacon probe can effective get to gastric cancer metastasis, the antibody of heparin will be modified on gold nanoparticles surface. Finally, a dual-targeted molecular imaging nanoprobe based on lncRNA GAS5 and heparin was constructed. The imaging effect of the probe on gastric cancer and its metastases was further evaluated at the cellular and animal levels. It is expected that this study will provide a new method and theoretical basis for the accurate diagnosis of gastric cancer metastasis.

侵袭转移是胃癌患者死亡的主要原因，胃癌转移的准确诊断对胃癌患者治疗方式选择和预后评估具有重要意义。靶向于特异碱基序列的分子信标技术可以从核酸层面为胃癌转移的准确诊断提供新方法。数据库及课题组前期的研究表明lncRNA GAS5在胃癌转移灶中高表达，与胃癌转移密切相关，可以作为胃癌侵袭转移的诊断靶标；我们前期构建了以金纳米颗粒作淬灭剂且靶向于lncRNA GAS5两段特异碱基序列的分子信标探针，体外研究发现其具有较好的靶向成像效果。文献报道肝素酶在转移性胃癌中高表达，课题组前期预实验发现肝素酶单克隆抗体可使纳米探针富集于肿瘤转移灶。据此，为保证分子信标探针有效富集于胃癌转移灶，本课题拟将肝素酶单克隆抗体修饰于金纳米颗粒上，构建基于lncRNA GAS5和肝素酶的双靶向探针，进一步在细胞及动物水平评价该探针对胃癌转移灶的成像效果。我们期望通过本研究，为胃癌转移的准确诊断提供新方法及理论依据。

侵袭转移是胃癌患者死亡的主要原因，胃癌转移的准确诊断对胃癌患者治疗方式的选择和预后的评估具有重要的临床意义。靶向于特异碱基序列的分子信标技术可以从分子层面为胃癌转移的准确诊断提供新方法。目的:构建长链非编码RNA (lncRNA) bc032469依赖金纳米粒分子信标(AuNPMB)，用于胃癌细胞的检测。材料与方法:根据金点阵与巯基功能化寡核苷酸之间Au-S相互作用的既定程序制备aunp - mb。更重要的是，通过一系列的体外和体内实验验证了AuNPMB的稳定性和靶向能力。结果:lncrna依赖探针成功用于基于aunp - mb的细胞内成像，荧光在GC细胞中有效发射，但在正常细胞中不能发射。值得注意的是，这种荧光发射与lncRNA BC032469的表达呈正相关。结论:研制了一种有效的胃癌细胞识别荧光成像探针。