Han Y, Katayama S, Futakuchi M, Nakamichi K, Wakabayashi Y, Sakamoto M, Nakayama J, Semba K. Targeting c-Jun Is a Potential Therapy for Luminal Breast Cancer Bone Metastasis.
Mol Cancer Res 2023;
21:908-921. [PMID:
37310848 DOI:
10.1158/1541-7786.mcr-22-0695]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 01/30/2023] [Accepted: 06/08/2023] [Indexed: 06/15/2023]
Abstract
Luminal breast cancer has the highest bone metastasis frequency among all breast cancer subtypes; however, its metastatic mechanism has not been elucidated because of a lack of appropriate models. We have previously developed useful bone metastatic cell lines of luminal breast cancer using MCF7 cells. In this study, we characterized bone metastatic MCF7-BM cell lines and identified c-Jun as a novel bone metastasis marker of luminal breast cancer. The protein level of c-Jun was upregulated in MCF7-BM cells compared with that in parental cells, and its deficiency resulted in the suppression of tumor cell migration, transformation, and reduced osteolytic ability. In vivo, dominant-negative c-Jun exhibited smaller bone metastatic lesions and a lower metastatic frequency. Histologic analysis revealed that c-Jun expression was heterogeneous in bone metastatic lesions, whereas c-Jun overexpression mediated a vicious cycle between MCF7-BM cells and osteoclasts by enhancing calcium-induced migration and releasing the osteoclast activator BMP5. Pharmacological inhibition of c-Jun by the Jun amino-terminal kinase (JNK) inhibitor JNK-IN-8 effectively suppressed tumorigenesis and bone metastasis in MCF7-BM cells. Furthermore, c-Jun downstream signals were specifically correlated with the clinical prognosis of patients with the luminal subtype of breast cancer. Our results illustrate the potential benefits of a therapy that targets c-Jun to prevent bone metastasis in luminal breast cancer.
IMPLICATIONS
c-Jun expression mediates bone metastasis in luminal breast cancer by forming a vicious cycle in the bone microenvironment, which reveals potential strategies for subtype-specific bone metastasis therapy.
Collapse