The Presence of Yin-Yang Effects in the Migration Pattern of Staurosporine-Treated Single versus Collective Breast Carcinoma Cells

Discovering natural products as potential inhibitors of SARS-CoV-2 spike proteins

The ongoing global pandemic caused by the SARS-CoV-2 virus has demanded the urgent search for effective therapeutic interventions. In response, our research aimed at identifying natural products (NPs) with potential inhibitory effects on the entry of the SARS-CoV-2 spike (S) protein into host cells. Utilizing the Protein Data Bank Japan (PDBJ) and BindingDB databases, we isolated 204 S-glycoprotein sequences and conducted a clustering analysis to identify similarities and differences among them. We subsequently identified 33,722 binding molecules (BMs) by matching them with the sequences of 204 S-glycoproteins and compared them with 52,107 secondary metabolites (SMs) from the KNApSAcK database to identify potential inhibitors. We conducted docking and drug-likeness property analyses to identify several SMs with potential as drug candidates based on binding energy (BE), no Lipinski's rule violation (LV), psychochemical properties within the pink area of the bioavailability radar, and a bioavailability score (BAS) not less than 0.55. Fourteen SMs were predicted through computational analysis as potential candidates for inhibiting the three major types of S proteins. Our study provides a foundation for further experimental validation of these compounds as potential therapeutic agents against SARS-CoV-2.

Targeting c-Jun Is a Potential Therapy for Luminal Breast Cancer Bone Metastasis

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.

Molecular Research and Treatment of Breast Cancer

Breast cancer is the leading cause of cancer-related deaths in the female population [...]