Triptolide's impact on ACER1 signaling: Inducing autophagy for triple-negative breast cancer suppression

Area of Science:

• Molecular Biology
• Cancer Research
• Cell Biology

Background:

• Triple-negative breast cancer (TNBC) lacks targeted therapy options due to the absence of estrogen receptor (ER), progesterone receptor (PR), and HER2.
• Developing novel therapeutic strategies for TNBC is crucial.

Purpose of the Study:

• To investigate the mechanism by which triptolide (TP) suppresses TNBC cell migration and invasiveness.
• To elucidate the role of the ACER1 gene in TP-mediated anti-cancer effects.

Main Methods:

• Western blotting to analyze autophagy-related protein expression (p62, LC3B-II, BNIP3, BNIP3L, ATG5, ULK1).
• PCR array screening to identify gene expression changes post-TP treatment.
• Gene overexpression and knockdown experiments.
• In vivo xenograft tumor models in mice.
• Hematoxylin and eosin (H&E) staining for toxicity assessment.

Main Results:

• TP treatment significantly suppressed MDA-MB-231 cell migration and invasiveness by activating autophagy.
• TP upregulated autophagy markers (LC3B-II, BNIP3, BNIP3L, ATG5, ULK1) and downregulated p62.
• ACER1 gene expression was altered by TP; its overexpression enhanced TP-induced apoptosis and autophagy, reducing migration/invasiveness.
• ACER1 knockdown reversed the effects of TP.
• TP inhibited tumor growth in vivo and modulated ACER1 and autophagy markers in tumor tissues without causing significant liver or kidney toxicity.

Conclusions:

• Triptolide effectively inhibits triple-negative breast cancer progression through an autophagy-dependent mechanism.
• The ACER1 gene plays a critical role in mediating triptolide's anti-cancer effects in TNBC.
• This study reveals a novel therapeutic pathway involving ACER1 and autophagy for TNBC treatment.