SERPINA3-ANKRD11-HDAC3 pathway induced aromatase inhibitor resistance in breast cancer can be reversed by HDAC3 inhibition

Endocrine resistance is a major challenge for breast cancer therapy. To identify the genes pivotal for endocrine-resistance progression, we screened five datasets and found 7 commonly dysregulated genes in endocrine-resistant breast cancer cells. Here we show that downregulation of serine protease inhibitor clade A member 3 (SERPINA3) which is a direct target gene of estrogen receptor & alpha; contributes to aromatase inhibitor resistance. Ankyrin repeat domain containing 11 (ANKRD11) works as a downstream effector of SERPINA3 in mediating endocrine-resistance. It induces aromatase inhibitor insensitivity by interacting with histone deacetylase 3 (HDAC3) and upregulating its activity. Our study suggests that aromatase inhibitor therapy downregulates SERPINA3 and leads to the ensuing upregulation of ANKRD11, which in turn promotes aromatase inhibitor resistance via binding to and activating HDAC3. HDAC3 inhibition may reverse the aromatase inhibitor resistance in ER-positive breast cancer with decreased SERPINA3 and increased ANKRD11 expression. SERPINA3 is a direct target gene of estrogen receptor and contributes to aromatase inhibitor resistance in breast cancer cells through an ANKRD11-HDAC3 pathway.

Automated summary

Endocrine resistance is a major challenge in breast cancer therapy. Through screening five datasets, we identified 7 commonly dysregulated genes in endocrine-resistant breast cancer cells. Our study suggests that downregulation of SERPINA3, a direct target gene of estrogen receptor alpha, contributes to aromatase inhibitor resistance. ANKRD11 acts as a downstream effector of SERPINA3 in mediating endocrine resistance by interacting with HDAC3 and upregulating its activity.