[Screening and establishment of human lung cancer cell lines with organ-specific metastasis potential]

Cancer metastasis is not only the malignant marker and characteristics, but also the main cause of failure to cure and lose their life in the patients with lung cancer. Lung cancer metastasis has organ-specific characteristics. The most common sites of lung cancer metastasis are mediastinal lymph node, brain, bone, liver and adrenal gland. The aim of this study is to screen and establish lung cancer cell model with organ-specific metastasis potential with human high-metastatic large cell lung cancer cell line L9981 established by our laboratory previously, and to provide cell models for studying the mechanisms and signal regulation of organ-specific metastasis of lung cancer.

The parent lung cancer cell line, L9981-Luc, was inoculated in the armpit of nude mice. The live animal imaging system, IVIS-200, was used to detect the lung cancer organ-specific metastasis every week. When the organ-specific metastasis were established, the nude mices bearing the lung cancer were sacrificed when they became moribund. Under sterile conditions, the organs (mediastinal lymph nodes, lung, spinal column and brain) with lung cancer organ-specific metastasis were removed and the metastasized nodules were dissected free of connective tissue and blood clots, and rinsed twice with medium. The metastasized nodules were finely minced using sterile scalpel blades in medium, and the cells were seeded in tissue culture dishes. Then, the cells with organ-specific metastasis potential were reinoculated into the armpit of nude mice, respectively. This processes were repeated to establish the organ-specific metastatic sublines of L9981-Luc cell line more than 10 times. Finally, the organ-specific metastasis sublines of L9981-Luc were screened and established, which the four cell lines have the characteristics only metastasized to brian, lung, bone and mediastinal lymph node.

A group of organ-specific metastasis cell lines which only metastasized to brian, lung, bone and mediastinal lymph node were successfully established through repeating reinoculatation, live animal imaging in nude mice, and screening and identification in vitro. We named the four cell lines as L9981-BoM, L9981-LuM, L9981-BrM and L9981-LnM, respectively. The L9981-BoM cell was only metastasized to bone. The l9981-LuM cell was only metastasized to lung. The L9981-BrM only metastasized to brain. The L9981-LnM cell was only metastasized to midiastinal lymph nodes.

A human large cell lung cancer cell model with bone, lung, brain and lymph node-specific metastasis potential was successfully established. It will be helpful to further study the molecular mechanisms and signal regulation of lung cancer organ- specific metastasis. It will be to also provide reliable cell model for developing new techniques and molecular targeting drugs of inhibiting or reversing lung cancer metastasis.