Quercetin inhibits truncated isoform of dopamine- and cAMP-regulated phosphoprotein as adjuvant treatment for trastuzumab therapy resistance in HER2-positive breast cancer

Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2 (HER2)-positive (HER2+) breast cancer (BC). The truncated isoform of dopamine- and cAMP-regulated phosphoprotein (t-DARPP) has been reported to be involved in trastuzumab therapy r...

Full description

Saved in:
Bibliographic Details
Main Authors: Han-Sheng Chang, Tzu-Chun Cheng, Shih-Hsin Tu, Chih-Hsiung Wu, You-Cheng Liao, Jungshan Chang, Min-Hsiung Pan, Li-Ching Chen, Yuan-Soon Ho
Format: Article
Language:English
Published: Tsinghua University Press 2024-09-01
Series:Food Science and Human Wellness
Subjects:
Online Access:https://www.sciopen.com/article/10.26599/FSHW.2022.9250213
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2 (HER2)-positive (HER2+) breast cancer (BC). The truncated isoform of dopamine- and cAMP-regulated phosphoprotein (t-DARPP) has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression. To evaluate the t-DARPP expression in BC, paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+ BC tumor tissues. We established 2 patient-derived xenografts (PDX) mice models to test the efficacy of trastuzumab, named model 1 (non-responder) and model 2 (responder). t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays. Instead, there is no response from the responder. Furthermore, mechanistic studies using transwell and western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins, enhance p95-HER2 expression and promote cell migration. We found that quercetin effectively reduced t-DARPP expression in HER2+ BC cells. In t-DARPP ShRNA-suppressed cells, quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest. In conclusion, the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+ BC patients has the potential as a biomarker for mitigating drug resistance.
ISSN:2097-0765
2213-4530