FABP5 inhibitor SBFI-26 regulates FOXM1 expression and Wnt signaling pathway in ovarian granulosa cell of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrinopathy among females of reproductive age. Due to its unclear etiopathogenesis, it is of vital significance to take a deeper understanding of molecular mechanisms underlying PCOS. Quantitative real-time PCR (RT-qPCR) and western blot were applied for detection of gene expression and protein expression individually. Cell Counting Kit-8 (CCK-8) and colony formation assays were used for the evaluation of cell proliferation while Caspase-3/9 activity was measured for the assessment of cell apoptosis. We found that FOXM1 was overexpressed in ovarian granulosa cell (OGC) of patients with PCOS. Functionally, upregulation of FOXM1 promotes the proliferative ability of PCOS-OGC cells. As for mechanism, FOXM1 exerts its functions in PCOS-OGC cell through activation of the Wnt signaling pathway. More importantly, a novel FABP5 inhibitor, SBFI-26, was verified to downregulate the expression of FOXM1 to impede the proliferation of PCOS-OGC cells. In addition, SBFI-26 inactivates Wnt signaling pathway in PCOS-OGC cells. FABP5 inhibitor SBFI-26 regulates FOXM1 expression and Wnt signaling pathway in OGC of patients with PCOS, which might provide a new perspective into PCOS treatment.

SBFI-26 enhances apoptosis in docetaxel-treated triple-negative breast cancer cells by increasing ROS levels

Introduction

Fatty acid binding protein 5 (FABP5) exhibits heightened expression levels in triple-negative breast cancer. The inhibitor of FABP5, Stony Brook fatty acid-binding protein inhibitor 26 (SBFI-26), has demonstrated the capacity to suppress cell proliferation, migration, and invasion. This study delves into the functional mechanism and impact of combining SBFI-26 with docetaxel in treating MDA-MB-231 cells of triple-negative breast cancer.

Methods

Various concentrations of docetaxel and SBFI-26 were chosen for individual or combined treatments. The effects of SBFI-26, docetaxel, or their combination on cell cycle arrest and apoptosis were assessed using flow cytometry. Western blotting was utilised to detect the expression of apoptosis-related proteins, namely cysteinyl aspartate-specific proteases 3 (Caspase3), B cell leukemia/lymphoma 2 (Bcl-2), and Bcl-2 associated X (Bax), while intracellular reactive oxygen species (ROS) levels were determined using a fluorescence spectrophotometer.

Results

The IC50 values for SBFI-26 and docetaxel in inhibiting MDA-MB-231 cells were determined to be 106.1 μM and 86.14 nM, respectively. Significantly, the combination treatment augmented the proportion of G1 phase (apoptotic) cells by 3.67-fold compared to the control group (P < 0.0001). Furthermore, the apoptosis rate in the combination group was 2.59-fold higher than that in the docetaxel group (P < 0.0001) and demonstrated a significant increase of 1.82-fold compared with the SBFI-26 group (P < 0.001). Analyses revealed a decrease in the protein expression of Bcl-2, while Bax and Caspase3 exhibited an increase in the combination group for MDA-MB-231 cells. Moreover, the combined treatment group demonstrated a 2.97-fold increase (P < 0.0001) in ROS fluorescence intensity compared to the control group, a noteworthy 1.39-fold increase (P < 0.01) compared to the SBFI-26 treatment group, and a substantial 1.70-fold increase (P < 0.0001) compared to the docetaxel treatment group.

Conclusion

These findings suggest that the co-administration of SBFI-26 with docetaxel effectively enhances apoptosis in triple-negative breast cancer MDA-MB-231 cells by elevating intracellular ROS levels.