The role of activated androgen receptor in cofilin phospho-regulation depends on the molecular subtype of TNBC cell line and actin assembly dynamics

Abstract

Triple negative breast cancer (TNBC) is highly metastatic and of poor prognosis. Metastasis involves coordinated actin filament dynamics mediated by cofilin and associated proteins. Activated androgen receptor (AR) is believed to contribute to TNBC tumorigenesis. Our current work studied roles of activated AR and cofilin phospho-regulation during migration of three AR+ TNBC cell lines to determine if altered cofilin regulation can explain their migratory differences. Untreated or AR agonist-treated BT549, MDA-MB-453, and SUM159PT cells were compared to cells silenced for cofilin (KD) or AR expression/function (bicalutamide). Cofilin-1 was found to be the only ADF/cofilin isoform expressed in each TNBC line. Despite a significant increase in cofilin kinase caused by androgens, the ratio of cofilin:p-cofilin (1:1) did not change in SUM159PT cells. BT549 and MDA-MB-453 cells contain high p-cofilin levels which underwent androgen-induced dephosphorylation through increased cofilin phosphatase expression, but surprisingly maintain a leading-edge with high p-cofilin/total cofilin not found in SUM159PT cells. Androgens enhanced cell polarization in all lines, stimulated wound healing and transwell migration rates and increased N/E-cadherin mRNA ratios while reducing cell adhesion in BT549 and MDA-MB-453 cells. Cofilin KD negated androgen effects in MDA-MB-453 except for cell adhesion, while in BT549 cells it abrogated androgen-reduced cell adhesion. In SUM159PT cells, cofilin KD with and without androgens had similar effects in almost all processes studied. AR dependency of the processes were confirmed. In conclusion, cofilin regulation downstream of active AR is dependent on which actin-mediated process is being examined in addition to being cell line-specific. Although MDA-MB-453 cells demonstrated some control of cofilin through an AR-dependent mechanism, other AR-dependent pathways need to be further studied. Non-cofilin-dependent mechanisms that modulate migration of SUM159PT cells need to be investigated. Categorizing TNBC behavior as AR responsive and/or cofilin dependent can inform on decisions for therapeutic treatment.

The endocrine disruptor cadmium modulates the androgen–estrogen receptors ratio and induces inflammatory cytokines in luminal (A) cell models of breast cancer

“…The role of AR in metastasis development includes coordinated actin filament dynamics mediated by cofilin and other connected proteins. Additional in vitro data showed that androgens enhanced cell polarization, stimulated wound healing and transwell migration rates and increased N/E-cadherin mRNA ratios [ 39 ]. Other evidence suggests that the AR might be a tumor suppressor in ERα -positive (BC, but a tumor promoter in ERα negative BC [ 40 ].…”

New Indole‐6‐Carboxylic Acid Derivatives as Multi‐Target Antiproliferative Agents: Synthesis, in Silico Studies, and Cytotoxicity Evaluation

“…Control, 3 b ‐treated HCT‐116 cells, and 6 e ‐treated HeLa cells were lysed with the lysis buffer after 72 h of treatment [37] . Cell lysates were then boiled in a water bath and sonicated.…”

“…Control, 3 b-treated HCT-116 cells, and 6 e-treated HeLa cells were lysed with the lysis buffer after 72 h of treatment. [37] Cell lysates were then boiled in a water bath and sonicated. For immunoblotting, equal quantities of protein from control and treated cells were separated using 10 % SDS-PAGE and blotted onto nitrocellulose membrane.…”