Therapeutic targeting of the pre-metastatic stage in human brain metastasis

We have used our established brain metastasis initiating cell (BMIC) models and gene expression analyses to characterize pre-metastasis in human lung-to-brain metastases. We utilized early passage Brain Metastasis cell lines derived from primary patient samples of lung-to-brain metastases in our work, as these samples are enriched for brain metastasis initiating cells (BMICs) that have already successfully completed the metastatic process. Previous work in our lab successfully established preclinical models of lung-to-brain BM(Nolte, et al., 2013; Singh, et al., 2017). Briefly, we injected mice through three different injection routes: a) intracranial (ICr), b) intrathoracic injections (IT), and c) intracardiac injections (ICa), where we were able to replicate the pre-metastatic and macro-metastatic stages from IT and ICa injections respectively(Singh, et al., 2017). Here, we have further isolated and characterized BMICs at each metastatic stage. BMIC lines transduced with GFP were injected into our BM models and were shown to reform tumors at each stage of the metastatic cascade, from primary lung (LT) and secondary brain (BT) tumor formation to the pre-metastatic (BMIT) and macro-metastasis (BMIC) stages of tumor growth. BMICs were isolated from BT, BMIT, and BMIC tumors and minimally cultured. RNA was extracted from these cells and submitted for RNA seq analysis.