RESUMO
OBJECTIVES: Cancer is the second most common cause of death, with breast cancer (BC) as the most frequently diagnosed neoplasm among females. The origin of BC is multifactorial and depends on environmental and genetic factors. The disease presents a significant challenge due to its drug resistance and frequent metastasis. Thus, new effective therapies and metastasis prevention are much needed. Rosmarinic acid (RA) is a natural polyphenol which possesses the ability to inhibit BC cell proliferation and demonstrates cytotoxic properties against those cells. In our study, we examined the effect of RA on the expression of ZEB1, MDM2, ABCB1, PTEN and TWIST1 genes in MCF-7 breast cancer cells. MATERIAL AND METHODS: MCF-7 cell cultures were treated with 0.2 µM doxorubicin (DOX) and 1.5, 15 or 50 µM of RA. Real-time PCR reaction was performed to analyze gene expression levels. RESULTS: PCR analysis showed a significant increase of the ZEB1 gene expression, which was about 3-fold for DOX 0.2 µM, 9-fold for 0.2 µM DOX + 1.5 µM RA and 0.2 µM DOX + 15 µM RA (p < 0.05), and about 6.5-fold for 0.2 µM DOX + 50 µM RA (p < 0.05). Furthermore, a decrease of the MDM2 gene expression was observed in all of the examined variants and was about 40-75% (p < 0.05). No influence of DOX and RA combined with DOX on the ABCB1, TWIST1 and PTEN genes was found. CONCLUSIONS: The results of our study suggest that RA might be used as an adjuvant therapeutic factor in BC treatment.