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Inhibitory Effects of Dopamine Receptor D1 Agonist on Mammary Tumor and Bone Metastasis
Kazumasa Minami1,2, Shengzhi Liu1,3, Yang Liu1,3
1Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA.
Abstract:
Dopaminergic signaling plays a critical role in the nervous system, but little is known about its potential role in breast cancer and bone metabolism. A screening of ~1,000 biologically active compounds revealed that a selective agonist of dopamine receptor D1 (DRD1), A77636, inhibited proliferation of 4T1.2 mammary tumor cells as well as MDA-MB-231 breast cancer cells. Herein, we examined the effect of A77636 on bone quality using a mouse model of bone metastasis from mammary tumor. A77636 inhibited migration of cancer cells in a DRD1-dependent fashion and suppressed development of bone-resorbing osteoclasts by downregulating NFATc1 through the elevation of phosphorylation of eIF2α. In the mouse model of bone metastasis, A77636 reduced osteolytic lesions and prevented mechanical weakening of the femur and tibia. Collectively, we expect that dopaminergic signaling might provide a novel therapeutic target for breast cancer and bone metastasis.
Insights
Dopamine receptor D1 (DRD1) agonist A77636 inhibits breast cancer cell growth and spread. This compound also protects bone by reducing osteoclast activity, suggesting a new therapeutic target for breast cancer bone metastasis.
Area of Science:
- Neuroscience
- Oncology
- Endocrinology
Background:
- Dopaminergic signaling is crucial in the nervous system.
- Its role in breast cancer and bone metabolism is largely unknown.
- Dopamine receptor D1 (DRD1) is implicated in various cellular processes.
Purpose of the Study:
- To investigate the effect of a DRD1 agonist, A77636, on breast cancer cells and bone metastasis.
- To explore the therapeutic potential of targeting dopaminergic signaling in breast cancer bone metastasis.
Main Methods:
- Screening of biologically active compounds to identify DRD1 agonists.
- In vitro studies using breast cancer cell lines (4T1.2, MDA-MB-231).
- In vivo mouse model of breast cancer bone metastasis.
Main Results:
- A77636 inhibited proliferation and migration of breast cancer cells in a DRD1-dependent manner.
- A77636 suppressed osteoclast formation by downregulating NFATc1 via eIF2α phosphorylation.
- In vivo, A77636 reduced osteolytic lesions and preserved bone mechanical strength.
Conclusions:
- Dopaminergic signaling, specifically via DRD1, plays a significant role in breast cancer progression and bone metastasis.
- A77636 demonstrates therapeutic potential for treating breast cancer with bone metastasis.
- Targeting dopaminergic signaling may offer a novel strategy for managing breast cancer complications.