Abstract 3693: Berry anthocyanidins inhibit key events of lung cancer metastasis: Effects on miRNA and protein targets

Abstract

Abstract Lung cancer continues to represent the largest cause of mortality in the world claiming over 1.3 million lives every year. The majority of patients who succumb to lung cancer die from cancer relapse and/or metastatic disease progression making the search for new anti-cancer and anti-metastasis agents imperative. Berry phytochemicals have received increasing attention lately for their various biological effects. We previously demonstrated notable synergistic anti-tumor effects of blueberry anthocyanidins (cyanidin, malvidin, peonidin, petunidin and delphinidin) against human lung cancer cells in culture and in vivo in nude mouse model. Herein, we show the anti-metastatic effects of all the 5 anthocyanidins individually and in combination in the highly aggressive and invasive human NSCLC H1299 cells. Using wound-healing and Boyden chamber assays, all the five anthocyanidins (25 µM each) were found to exhibit varied inhibitory effects on H1299 cell migration and invasion. However, an equimolar mixture containing either 3.125 or 6.25 µM of each anthocyanidin elicited similar inhibition of H1299 cell migration and invasion indicating a synergistic effect. Given the multi-complexity of the metastasis process, the effect of anthocyanidins on a plethora of molecular targets mediating of the metastatic process was analyzed by western blotting. We found that berry anthocyanidins decreased the expression of several metastatic and angiogenic mediators, viz; matrix metalloproteinases (MMP-2 and MMP-9), vascular endothelial growth factor (VEGF), c-MYC, NOTCH-1, WNT1. Furthermore, the anthocyanidins effectively inhibited TNF-α-induced NF-κB activation and suppressed of ERK-1/2 activation, which could further explain their anti-invasive capabilities. Recently, emerging evidence also suggests the involvement of miRNAs in regulating various processes of cancer cell invasion and metastasis. Effect of anthocyanidins on four such miRNAs frequently downregulated in NSCLC and implicated in lung cancer invasion and metastasis (miR-126, miR125a-5p, miR200c) and lung cancer relapse (miR-34a) was analyzed by qPCR. We observed a significant increase in the expression of all the four miRNAs by the anthocyanidins. Target prediction scan for gene targets revealed several angiogenic signaling molecules to be regulated by these miRNA's. Our results thus establish that protective properties of anthocyanidins may arise, at least, in part, from its capability to manipulate some distinct and some overlapping miRNA and protein targets that may potentiate the anti-cancer and anti-metastatic effects of the berry anthocyanidins. Collectively, our data suggest that berry anthocyanidins may provide a safe, effective, unconventional and user-friendly approach to prevent or delay the onset of lung cancer recurrence and metastasis (Supported from KLCRP and Agnes Brown Duggan Endowment). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3693. doi:10.1158/1538-7445.AM2011-3693