The Role of Tumor Microenvironment and Immune Dynamics in Hormone-Sensitive Breast Cancer: Insights from ICB and Targeted Therapy in a Rat Model

Breast cancer hormone receptor (HR) estrogen and progesterone (ER/PR) positive tumors were generated in an outbred rat model (Sprague-Dawley) through the injection of the carcinogen N-nitrosomethylurea (NMU). These tumors were treated with immune checkpoint blockade (anti PD-L1) in combination with targeted therapies, including an TBK1/IKBKE inhibitor, a KMT5B/C inhibitor, a TGF-b inhibitor, and a selective estrogen receptor degrader (SERD). This dataset includes single-cell RNA sequencing (scRNA-seq) data from tumors subjected to various treatment setups. Whole-tumor digestion was performed to preserve a comprehensive representation of the tumor microenvironment. The study aims to identify mechanisms that sensitize HR postive tumor subtypes to immune checkpoint blockade therapy.