Ternary complex components responsible for rapid LDL internalization as biomarkers for breast cancer associated with proliferation and early recurrence.

The ternary complex of PGRMC1-σ2R/TMEM97-LDLR has recently been discovered and plays a role in cholesterol transport. This study investigated whether individual components of that complex are prognostic breast cancer biomarkers and defined expression in established molecular subtypes. 4,463 invasive breast cancers were analyzed as a function of molecular and phenotypic markers, estimates of cellular proliferation, and recurrence-free survival.

Osteopontin is a therapeutic target that drives breast cancer recurrence.

Recurrent breast cancers often develop resistance to standard-of-care therapies. Identifying targetable factors contributing to cancer recurrence remains the rate-limiting step in improving long-term outcomes. In this study, we identify tumor cell-derived osteopontin as an autocrine and paracrine driver of tumor recurrence.

Autophagy is required for mammary tumor recurrence by promoting dormant tumor cell survival following therapy.

Background: Mortality from breast cancer is principally due to tumor recurrence. Recurrent breast cancers arise from the pool of residual tumor cells, termed minimal residual disease, that survive treatment and may exist in a dormant state for 20 years or more following treatment of the primary tumor. As recurrent breast cancer is typically incurable, understanding the mechanisms underlying dormant tumor cell survival is a critical priority in breast cancer research.

Rare subclonal sequencing of breast cancers indicates putative metastatic driver mutations are predominately acquired after dissemination.

Background: Evolutionary models of breast cancer progression differ on the extent to which metastatic potential is pre-encoded within primary tumors. Although metastatic recurrences often harbor putative driver mutations that are not detected in their antecedent primary tumor using standard sequencing technologies, whether these mutations were acquired before or after dissemination remains unclear.

Methods: To ascertain whether putative metastatic driver mutations initially deemed specific to the metastasis by whole exome sequencing were, in actuality, present within rare ancestral subclones of the primary tumors from which they arose, we employed error-controlled ultra-deep sequencing (UDS-UMI) coupled with FFPE artifact mitigation by uracil-DNA glycosylase (UDG) to assess the presence of 132 "metastasis-specific" mutations within antecedent primary tumors from 21 patients.

B3GALT6 promotes dormant breast cancer cell survival and recurrence by enabling heparan sulfate-mediated FGF signaling.

Breast cancer mortality results from incurable recurrences thought to be seeded by dormant, therapy-refractory residual tumor cells (RTCs). Understanding the mechanisms enabling RTC survival is therefore essential for improving patient outcomes. Here, we derive a dormancy-associated RTC signature that mirrors the transcriptional response to neoadjuvant therapy in patients and is enriched for extracellular matrix-related pathways.