人源性的小细胞肺癌异种移植动物模型及耐药模型的建立

Establishment of A Patient-derived Xenotransplantation Animal Model for Small Cell Lung Cancer and Drug Resistance Model

背景与目的小细胞肺癌(small cell lung cancer, SCLC)是细胞分化程度低,恶性程度高,生长速度快,早期容易发生转移的恶性肿瘤。目前SCLC患者的临床治疗以化疗为主,但是在治疗6个月-9个月后极易发生获得性耐药而复发。因此,构建有效的临床前SCLC动物模型具有重要的临床价值。人源性肿瘤异种移植动物模型(patient-derived xenotransplantation, PDX)能够较好地保留原发肿瘤的特性,是比较理想的临床前动物模型。本研究旨在构建中国人来源的SCLC PDX动物模型,并诱导构建化疗耐药的PDX模型,为研究SCLC耐药机制及个体化治疗提供实验模型。方法取临床SCLC患者的新鲜手术切除标本或穿刺标本,移植至重度免疫缺陷小鼠NOD-PrkdcscidIL2rgtm1/Bcgen(B-NSGTM)皮下,HE染色及免疫组化对比移植肿瘤组织与患者肿瘤组织的病理学一致性。给予可稳定传代的每一代PDX模型小鼠腹腔注射8个周期的化疗药物(顺铂8 mg/kg+依托泊苷5mg/kg),定期监测荷瘤小鼠体质量和肿瘤体积,对长至1,000 mm^3大小的肿瘤进行传代移植。结果本研究收集并移植9例SCLC肿瘤标本,成功构建可多次传代SCLC PDX模型3例并成功诱导其耐药模型,模型较好地保留了原发肿瘤的特征。结论成功构建了SCLC PDX模型及其耐药模型,建模成功率为33%。为后续研究人的SCLC耐药机制、临床药物筛选以及个体化治疗提供了实验平台。

Background and objective Small cell lung cancer(SCLC) is characterized by poor differentiation, high malignancy and rapid growth fast, short double time, early and extensive metastatic malignancy. In clinical, chemotherapy is the main treatment method, while resistance to multiple chemotherapy drugs in six to nine months has been a major clinical challenge in SCLC treatment. Therefore, It has important clinical value to building SCLC aninimal model which is similar to patients with SCLC. Animal model of xenotransplantation(PDX) from the patients with small cell lung cancer can well retain the characteristics of primary tumor and is an ideal preclinical animal model. The study is aimed to establish SCLC PDX animal model and induce the chemoresistance model to help to study the mechanism of chemoresistance and individual treatment. Methods Fresh surgical excision or puncture specimens from SCLC patients were transplanted into B-NSGTM mice subcutaneous tissues with severe immunodeficiency in one hour after operation the B-NSGTM mice subcutaneous in 1 hour, and inject chemotherapy drugs intraperitoneally after its tumor growed to 400 mm^3 with EP which is cisplatin 8 mg/kg eight days and etoposide 5 mg/kg every two days until 8 cycles. Measure the tumor volum and mice weights regularly, then re-engrafted the largest tumor and continue chemotherapy. Results Nine cases were conducted for B-NSG mice modeling. Three of nine cases could be engrafted to new B-NSG mice at least two generation. The SCLC PDX animal models have been established successfully. After adopting chemotherapy drugs, the chemoresistance PDX models have been established. High homogeneity wasfound between xenograft tumor and patient’s tumor in histopathology, immunohistochemical phenotype(Syn, CD56, Ki67). Conclusion The SCLC PDX animal model and the chemoresistance PDX animal model have been successfully constructed, the success rate is 33%, which provides a platform for the clinical research, seeking for biological markers and choosing individual treatment methods of SCLC.