RESUMEN
The incidence rate of lung cancer is continually increasing, and lung cancer is the leading cause of cancer-related death worldwide. Nevertheless, few therapeutic methods are available for lung cancer. Therefore, establishing appropriate lung cancer animal models is important to investigate mechanisms and to evaluate new drugs for lung cancer. In the present study, we transplanted non-small cell lung cancer A549 human adenocarcinoma cells (2x10(4), 2.0x10(5), and 2.0x10(6) cells) into the right lobe of BALB/c nude mice via the intercostal space to develop an orthotopic lung cancer animal model that is minimally invasive and similar to human lung cancer. We then investigated the incidence rate and severity of lung cancer according to the A549 cell number (2x10(4), 2.0x10(5), and 2.0x10(6) cells) and transplantation periods (4~23 days). Lung cancer development was confirmed with gross examination, which was supported by histopathological examination. These results indicate that the incidence rate and severity of lung cancer was increased depending on the number of transplanted cells and transplantation period which the cell number and duration are increasing risk of lung cancer. Thus, this study can provide appropriate reference data to develop an orthotopic lung cancer animal model using the non-small cell lung cancer A549 cell line for researching mechanisms and evaluating candidate drugs, including various approaches for treating lung cancer.