BACKGROUND/AIM: Triple-negative breast cancers (TNBC) lack expression of three important receptors, and have limited treatment options. High expression of junctional adhesion molecule-A (JAM-A) has been linked with aggressive tumor phenotypes including TNBC. This study aimed to evaluate the bioactivity of a JAM-A-down-regulating compound, Tetrocarcin-A, in TNBC. MATERIALS AND METHODS: TNBC cell viability, colony formation and xenograft growth were examined in Tetrocarcin-A-treated HCC38 human cells, 4T1 mouse cells or patient-derived primary cells. Protein expression of cell fate signaling effectors was examined by immunoblotting (versus transient JAM-A gene silencing). Apoptotic pathways were investigated in parallel. RESULTS: Tetrocarcin-A reduced TNBC cell viability in vitro and in an in ovo/semi-in vivo xenograft model. Tetrocarcin-A-induced JAM-A down-regulation and reduced ERK phosphorylation, followed by c-FOS phosphorylation on its transcription-regulating residue, which down-regulated several inhibitor of apoptosis (IAP) proteins and induced caspase-dependent intrinsic pathway of apoptosis. CONCLUSION: Tetrocarcin-A merits further investigation as a novel anti-tumor agent in TNBC. Copyright
BACKGROUND/AIM: Triple-negative breast cancers (TNBC) lack expression of three important receptors, and have limited treatment options. High expression of junctional adhesion molecule-A (JAM-A) has been linked with aggressive tumor phenotypes including TNBC. This study aimed to evaluate the bioactivity of a JAM-A-down-regulating compound, Tetrocarcin-A, in TNBC. MATERIALS AND METHODS: TNBC cell viability, colony formation and xenograft growth were examined in Tetrocarcin-A-treated HCC38 human cells, 4T1 mouse cells or patient-derived primary cells. Protein expression of cell fate signaling effectors was examined by immunoblotting (versus transient JAM-A gene silencing). Apoptotic pathways were investigated in parallel. RESULTS:Tetrocarcin-A reduced TNBC cell viability in vitro and in an in ovo/semi-in vivo xenograft model. Tetrocarcin-A-induced JAM-A down-regulation and reduced ERK phosphorylation, followed by c-FOS phosphorylation on its transcription-regulating residue, which down-regulated several inhibitor of apoptosis (IAP) proteins and induced caspase-dependent intrinsic pathway of apoptosis. CONCLUSION:Tetrocarcin-A merits further investigation as a novel anti-tumor agent in TNBC. Copyright
Authors: Viktorija Juric; Lance Hudson; Joanna Fay; Cathy E Richards; Hanne Jahns; Maïté Verreault; Franck Bielle; Ahmed Idbaih; Martine L M Lamfers; Ann M Hopkins; Markus Rehm; Brona M Murphy Journal: Cell Death Dis Date: 2021-08-03 Impact factor: 8.469