Luteolin-Treated 4T1 Cell-Derived Exosomes as Novel Antiproliferative Agents In Vitro and In Vivo

Breast cancer is the most widespread malignancy among women worldwide. Luteolin, a flavonoid, has demonstrated anti-cancer effects by triggering apoptosis in tumor cells. Exosomes are gaining much attention for cancer therapeutic approaches due to multitude of beneficial effects. This study is aimed to investigate the possible potential of exosomes derived from luteolin-treated 4T1 cells to ameliorate tumor in comparison to luteolin treatment only.

In this study, 4T1 cell culture was exposed to luteolin. Following exosome extraction, they were characterized using field emission scanning electron microscopy, dynamic light scattering and western blot analysis. MTT assay was performed in order to evaluate cell viability after exposure to different concentrations of luteolin and exosomes. An in vivo breast cancer model was induced via subcutaneous injection of 4T1 cells to the BALB/C mice. After 14 days, tumor volume was measured, and expression of RhoA and ERK mRNAs were quantified by Real Time PCR.

The MTT assay demonstrated that exosomes from luteolin-treated 4T1 cells at a concentration of 320 μg/μl reduced cell viability by approximately 70% in a dose-dependent manner. Tumor volume in the exosome-treated group decreased by 57% relative to the tumor group, while the luteolin-treated group demonstrated a 39% reduction. Furthermore, RhoA gene expression was substantially downregulated in the exosome-treated group, and exosomes were more effective than luteolin in reducing ERK gene expression.

Exosomes derived from luteolin-treated 4T1 cells effectively suppress breast cancer cell growth by reducing 4T1 cell viability and by decreasing tumor volume and downregulating tumor-associated genes RhoA and ERK. These results propose a novel therapeutic strategy for breast cancer, highlighting the promising potential of exosomes as an efficient drug delivery system.