BACKGROUND AND OBJECTIVEWith the ongoing need to improve therapy for lung cancer, there has been an increasing interest in the development of reliable preclinical models to test novel therapeutics. The aim of this study is to establish a patient-derived lung cancer xenograft model in mice and to observe the biological characteristics of xenografts.

METHODSSurgically resected tumor specimens from patients with lung cancer were implanted in the subcutaneous layer of the NOD/ SCID mice. Cancer specimens of percutaneous lung biopsy by CT fluoroscopy were implanted into the subrenal capsule of nude mouse. The subcutaneous carcinoma was surgically removed when it grew to approximately 1.0 cm in diameter, and then re-transplanted into new nude mice. The growth process of transplanted tumor was observed. Expression of CEA, cytokeratin, and Ki67 were detected by immunohistochemistry. Mutations in the exons 18-21 of EGFR and exons 12,59 of K-ras of primary and xenograft tumors were examined. The cell cycle of xenograft tumor cells was analyzed by flow cytometry.

RESULTSEleven cases were conducted for NOD/SCID mice and nude mice modelling. The patient-derived lung cancer xenografts have been established successfully, and the tumor could be passed to new nude mice, including No 2 model (adenocasinoma), No. 3 model (small cell lung cancer), and No.5 model (squamous cell cancer). High homogeneity was found between xenograft tumors and human lung cancer in histopathology, immunohistochemical phenotype, and EGFR, K-ras mutation status. The S-phase fraction of xenograft cell cycle was prolonged, which indicated that the xenografts remains highly proliferated.

CONCLUSIONThe xenotransplantation models established for patient-derived lung cancer in immune deficient mice. The success rate is 27%. This model system displayed the biological characteristics of human lung cancer, suggesting that it may provide a stable, reliable, and useful animal model in human lung cancer research.