Exome-capture RNAseq of microdissected FFPE human breast cancer cells, cancer-associated fibroblasts, and surrounding tumor-infiltrating lymphocytes

Here we describe the development of a robust method for RNA extraction and exome-capture RNA-sequencing of laser-capture microdissected (LCM) tumor cells (TC) and stromal immune cells (TIL) based on their morphology. We applied this method on seven tumor specimens and microbiopsies of triple-negative breast cancers (TNBC) stored in FFPE blocks. Together, we showed that combining LCM and RNA-sequencing on archived FFPE blocks is feasible and allows spatial transcriptional characterization of the tumor microenvironment.