Spatial transcriptomics reveals functional compartmentalization of estrogen receptor positive (ER+) breast cancer

Intratumor heterogeneity is one of the hallmarks of cancers, including breast cancers. We performed spatial transcriptomics to profile heterogeneous cell populations within ER+ breast cancers as well as to determine their importance for estrogen-dependent tumor growth. Our analysis has revealed the key functional compartments for developing targeted therapeutic strategies against ER+ breast cancers. Two ER+ breast cancer patient-derived xenografts (PDXs) with opposite estrogen responses for tumor growths were used for the analysis: estrogen-suppressed GS3 and estrogen-dependent SC31 models. GS3 and SC31 tumors treated with placebo or 17β-estradiol (E2) were analyzed using spatial transcriptomics.