肺癌体外模型与个体化治疗的关键技术研究

Lung cancer is the most common cancer in the world and it is the leading death cause in tumor in our country. Though there are many available anti-tumor drugs, patients may respond very differently to the anti-tumor drugs. The aim of tumor personalized therapy includes selecting drugs according to the characters of patient tumor and adjusting the therapy in accordance with the therapy result. Recent researches showed that tumors derived from patient could be grafted into nude mice and form tumors, which was called patient-derived xenograft(PDX). PDX is much better than tumors formed in nude mice with cultured cell lines for that PDX can maintain the heterogenicity of tumor and is more related to clinical tumors. But it is very difficult to establish a specific PDX model for that very few tumors will grow when leaving the environment in patient. This results in the low transplant success rate, which is about 30-40%. In the previous study, we found that a kind of autophagy inducer could promote the colony formation of cultured lung cancer cell lines and enhance the tumor formation and growth in nude mice. These results suggested that the autophagy inducer we used might also promote the tumors survival and growth in nude mice. In this project, we will study the role of the autophagy inducer in improving non-small cell lung cancer(NSCLC) patient-derived xenograft growth in nude mice and its mechanism in detail. All PDXs established will be then studied for its relevance to clinical data and its application in personalized therapy. The results of this study may solve the key problem that restricts the establishement of PDX and expand its application in NSCLC personalised therapy. The results of this study may also give some good suggestion for personalized therapy in other cancers.

肺癌是世界范围内最常见的恶性肿瘤，是我国居民第一肿瘤死因。面对众多肿瘤治疗药物，如何根据病人的肿瘤特点，选择最有效药物进行治疗，并根据治疗效果及时调整方案，是肿瘤个体化治疗的目标。病人来源的异体移植模型（patient-derived xenograft，PDX）近年来在病人特异性肿瘤药物的筛选上发挥着重要作用，但较低的构建成功率限制其更广范围应用。本单位前期研究发现一种特殊的细胞自噬诱导剂可增强肺癌细胞系体外集落形成能力和裸鼠体内成瘤能力，本研究拟在此基础上探讨该诱导剂是否可增强非小细胞肺癌病人的肿瘤组织在裸鼠体内的成瘤能力及其可能的作用机理，对PDX模型的临床相关性和临床应用进行研究，以期实现肺癌个体化治疗的同步药物筛选。本研究将有可能突破制约肺癌PDX模型构建成功的关键因素，大大提高PDX模型构建成功率，有力地推动肺癌病人的个体化治疗，并可为其它肿瘤的个体化治疗研究提供借鉴。

肺癌是世界范围内最常见的恶性肿瘤，是我国居民第一肿瘤死因。面对众多的肿瘤治疗药物，如何根据肿瘤的特点，选择最有效药物进行治疗，并根据治疗效果及时调整方案，是肿瘤个体化治疗的目标。病人来源的异体移植模型（patient-derived xenograft，PDX）近年来在病人特异性肿瘤药物的筛选上发挥着重要作用，但较低的构建成功率及其高费用限制其广泛应用。本研究将目标定位于提高PDX模型的构建成功率，我们通过控制肿瘤离体时间、调整肿瘤接种方法和选择合适的免疫缺陷鼠，共进行了32例病人肿瘤组织的PDX模型构建，成功获得15例PDX模型。在对影响因素进行分析时，我们发现原代肿瘤有镜下侵袭者建模成功率（70.6%）明显高于无侵袭者（20%），差异具有统计学意义；NSG小鼠、NOD-SCID小鼠和BALB/C裸鼠的建模成功率分别为100%、50%和18.2%，差异具有统计学意义。而患者性别、吸烟史和肿瘤的病理类型、TNM分期、肿瘤分化等对PDX模型成功率均无显著性影响。在小鼠体内长成的肿瘤保留着较好的肿瘤结构，与来源于病人的肿瘤在结构上具有较好的一致性。随后我们将PDX模型应用于新型纳米抗肿瘤药物临床前研究，发现金属富勒醇对肺癌有较好的生长抑制作用，特别是对鳞癌的效果较好，金属富勒醇处理组α-catenin和E-cadherin的表达显著上调，该研究表明金属富勒醇对非小细胞肺癌，尤其是肺鳞癌有较好的抑制作用，生物安全性好，可望为肺鳞癌的治疗带来新的契机。在将PDX模型应用于泮托拉唑和奥西替尼联用的机理研究时，我们发现无论在EGFR野生型还是在EGFR耐药突变型的人肺癌PDX模型中，与单独使用奥西替尼相比，泮托拉唑与奥西替尼联用时对肺癌细胞生长抑制作用最明显，研究结果表明泮托拉唑与奥西替尼联用有可能作为一种新的靶向治疗后出现耐药的肺癌治疗手段。本研究将PDX模型构建成功率提高到约50%，获得的模型成功应用于新药的药效评价和肺癌治疗药物机理研究，为肺癌患者个体化用药提供了一种新的药物体内筛选工具。