Abstract 1764P
Background
Interleukin 1- β (IL-1β), secreted in tumor associated macrophages (TAMs) and inflammasome pathway, is a pivotal element in endocrine therapy resistance. Calreticulin, in damaged/dying cells, leads to oligomerization of NOD-like receptor family, pyrin domain containing 3(NLRP3), adaptor protein apoptosis-related speck like protein containing a CARD (ASC) and the effector caspase-1 that secretes IL-1β. In breast cancer (BC), NLRP3 activation was involved in BC progression.Thymoquinone (TQ), a phytochemical, inhibited NLRP3 in melanoma. Here, TQ impact on inflammasome pathway is tested for the first time in hormone receptor positive (HR+) BC.
Methods
20 HR+ BC blood samples were collected. Peripheral Blood mononuclear cells (PBMCs) were isolated. TAMs were in-vitro differentiated from monocytes isolated from PBMCs. PBMCS and TAMS were cultured for 24, 48 and 72 hrs with 20, 50 and 100μM TQ concentrations. Relative expression of IL-1β, inflammasome proteins and GAPDH was quantified (RealTime PCR).
Results
TQ significantly downregulated IL-1β in PBMCs at 20μM/24 h (P=0.0375), 50μM/24, 48, 72 h (p=0.0400, p=0.0234, p=0.0006), 100μM/24, 48, 72 h (p=0.0002, p=0.0180, p=0.0320) as well as in TAMs at 100μM/24 hrs (p=0.0064). Calreticulin was markedly upregulated(p<0.0001) at 20μM/24 h and repressed at 50 and 100μM (p=0.0044). TQ significantly decreased its expression after 48 hrs in a dose dependant manner at 50μM and 100μM (p=0.0345, p=0.0043). TQ dampened Caspase-1 after 24 h at 50μM (p=0.0302) followed by an unexpected increase at 100μM (p=0.0066) while after 48 h it was dramatically repressed in a dose dependent manner at 50 μM and 100 μM (p=0.0320, p=0.0075). TQ increased NLRP3 and ASC expression at 50μM/24h (p=0.0017, p=0.0009) followed by undetectable expression at 100μM. At 48 h, an intreseting pattern was observed, at first TQ downregulated NLRP3 (p=0.0359) and ASC at 50μM followed by an unexpected increase at 100μM (p=0.0003, p=0.0104).
Conclusions
TQ significantly inhibited IL-1β and its upstream inflammasome components highlighting its potiential role as an excellent adjuvant in HR+ BC patients lessening IL-1β-induced therapy resistance and relapse.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Molecular Pharmacology Research Group, Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo, Egypt.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.