Reducing PMA-induced COX-2 expression using a herbal formulation in MCF-7 breast cancer cells
(1) The International School Bangalore (TISB), Bangalore, India, (2) International Stemcell Services Limited, Bangalore, India
Cyclooxygenase-2 (COX-2) is the inducible form of a group of enzymes that catalyze the conversion of arachidonic acid to prostaglandins. This isoform is often overexpressed in breast cancer cells. COX-2 overexpression correlates with an aggressive phenotype in breast cancer, including higher histological grade, larger tumor size, estrogen receptor (ER) negativity, and human epidermal growth factor receptor 2 (HER-2)/neu positivity. Another study, via molecular, animal, and human investigations, supported that COX-2 expression increases as cancer develops, getting progressively worse during the metastatic phase through the release of vascular endothelial growth factor (VEGF). Traditional medicine or herbal compounds have been gaining increasing popularity for alternative treatment for cancer alone and in conjunction with treatments. Green tea and turmeric are famous for their numerous beneficial effects on the body, including anti-oxidative, chemo-preventive, chemo-protective, anti-inflammatory properties. COX-2 expression was induced using phorbol-12-myristate-13-acetate (PMA). This study tested the effect of the herbal formulation HF1 (mainly composed of (-)-epigallocatechin-3-gallate (EGCG) and curcumin) on the COX-2 mRNA levels in the breast cancer cell line MCF-7. We hypothesized that PMA-induced overexpression of COX-2 in MCF7 cells would be eliminated after exposure to HF1. PMA increased COX-2 levels by 3-fold as compared to the untreated MCF-7 culture (no PMA, no HF1). However, when cells were treated with HF1 alongside PMA, we observed a 60% decrease in COX-2 levels.