A new lung cancer model that mimics the behavior of the disease outside the body (ex vivo) was recently developed by investigators at Houston Methodist Research Institute. The team thoroughly tested the model and recently published the study results in The Annals of Thoracic Surgery. Senior author Min P. Kim and colleagues utilized the model to explore the processes involved in lung cancer metastasis and the spread of cancer to distant organs or tissues throughout the body.
The “4-D” lung cancer model was produced by removing all the cells of a vertebrate lung, leaving only the extracellular matrix, the substances secreted by cells that provide them with structural and biochemical support. Then, tumor cells were introduced into the acellular (empty of cells) lung. “3-D” cancer nodules grow over time, and a fourth dimension is then apparent: the “flow” of fluids and tumor cells between lungs through blood vessels, which characterize the various phases of progression including metastasis.
As such, the model allows researchers to study the progression of primary tumors, the release of tumor cells to the circulation, and the appearance of metastatic lesions all in a matter of days. The team also found some characteristic gene expression in circulating tumor cells which are associated with poor survival in cancer patients, providing clues for new directed therapies.
All these features are not found in any other in vitro or in vivo model. The former does not normally allow the study of tumor progression over time, while the latter usually often needs a long time of progression before any results can be studied.
Most lung cancer patients have metastasis at the time of diagnosis, clearly associated with worse prognosis and ultimately death. Researchers developed a model that can form tumor nodules and be studied over time to better characterize the multistep metastatic process and reflect the biology of tumor cells. The main advantage of this model is the possibility to study various lung cancer cell lines in the laboratory. In the future, it can also be used to develop novel therapeutic approaches addressing metastasis and lead to improved survival and patients’ quality of life.