Explore the role of RHAMM in invasion/metastasis of breast cancer

To understand the mechanism of breast cancer invasion and metastasis, we collected tumor tissue from a cohort of 120 breast cancer patients and performed a Nanostring gene profiling assay (26 cases were removed from further analysis during quality control). Differential gene expression (DGE) analysis was done by comparing patients with/without lymph node metastasis lymph nodes. To explore the role of RHAMM in breast cancer invasion and metastasis, we created an RHAMM Related Signature (RRS) by intersecting the top 50 genes with another DGE list generated from a murine model wherein overexpression of an oncogenic RHAMM isoform increased cell motility in vivo tumor engraftment, and metastasis to identify RHAMM-related transcriptome changes specifically. We designed a custom Nanostring nCounter assay for quantitative assessment of expression of 356 genes consisting of TME interactions, inflammatory signaling, steroid receptor and growth factor signaling, cell cycle, apoptosis, and DNA repair, plus PAM50 classifier genes. A total of 26 cases were excluded for data analysis during quality control step.