American Association for Cancer Research
15357163mct200807-sup-252036_2_supp_6948818_qpn9jn.pdf (104.58 kB)

Supplementary Figure 3 from Activity of Combined Androgen Receptor Antagonism and Cell Cycle Inhibition in Androgen Receptor Positive Triple Negative Breast Cancer

Download (104.58 kB)
journal contribution
posted on 2023-04-03, 18:43 authored by Jessica L. Christenson, Kathleen I. O'Neill, Michelle M. Williams, Nicole S. Spoelstra, Kenneth L. Jones, G. Devon Trahan, Jordan Reese, Elaina T. Van Patten, Anthony Elias, Joel R. Eisner, Jennifer K. Richer

Single-cell RNAseq of AR expressing MDA-MB-453 TNBC cells. scRNAseq was performed on untreated MDA-MB-453 cells cultured in full serum media. Cells were divided in groups based on their expression of AR, ARLow and ARHigh. (A) tSNE plot of AR levels in cells clustered by gene expression. (B) IPA was performed on the genes differentially expressed between ARLow and ARHigh groups. Shown are the top 50 most significantly altered disease and function pathways and canonical pathways.








Triple-negative breast cancer (TNBC) is an aggressive subtype, with a peak recurrence rate within the first few years after diagnosis. Few targeted therapies are available to treat this breast cancer subtype, defined by the lack of estrogen receptor (ER) and progesterone receptor and without amplification of human epidermal growth factor receptor 2 (HER2). Although cell cycle cyclin-dependent kinase (CDK) 4/6 inhibitors are approved for treatment of ER-positive (ER+) breast cancer, they have not proven effective as monotherapy in patients with TNBC. The androgen receptor (AR) has emerged as a therapeutic target in a subset of TNBCs and with significant clinical benefit observed in multiple trials. The purpose of this study was to investigate the preclinical activity of the CDK4/6 inhibitor, abemaciclib, in combination with an agent that targets both androgen biosynthesis and AR activity, seviteronel, using TNBC cell lines expressing high AR, cell line xenografts, and an AR-positive (AR+), androgen-responsive TNBC patient-derived xenograft (PDX). Single-cell RNA sequencing demonstrated heterogeneity in AR levels, even in a highly AR+ cell line, and identified cell cycle pathway activation in ARHigh- versus ARLow-expressing cells. Combination treatment with the cell cycle CDK4/6 inhibitor, abemaciclib, and seviteronel showed synergy in an AR+ TNBC model compared with each drug alone. Although cell cycle inhibitors are FDA approved for use in ER+ breast cancer, our studies suggest that they may also be effective in AR+ TNBC, perhaps combined with AR-targeted agents.

Usage metrics

    Molecular Cancer Therapeutics





    Ref. manager