👤 Natsuko Aida

Apigenin, found in a variety of vegetables and fruits, exhibits anti-oxidant, anti-inflammatory and anticancer effects. Recently, we reported the possibility that apigenin induces apoptosis in human lung adenocarcinoma A549 cells through the miR-34a-5p/SNAI1/caspase-3/-7 pathway. Understanding how apigenin triggers apoptosis in cancer cells will help lay the groundwork for developing effective cancer treatments. The lung adenocarcinoma A549 Cell line was used. To determine whether caspase-8 or caspase-9 is activated, we performed a caspase activity assay. Real-time qRT-PCR was performed to identify mRNAs that may stimulate the upstream pathways, including tumor necrosis factor-a (TNF-a), spondin-2 (SPON2), and interferon-a2 (IFNA2), which are known to be involved in apoptosis in various cancer cell lines. In apigenin-treated cells, early-stage apoptosis was observed at 24 h, with increased activity of caspase-8 at 18 h and again at 24 h, and caspase-9 at 24 h and further at 48 h. However, mRNA levels of caspase-8 and caspase-9 significantly decreased after 24 h. Real-time RT-qPCR analysis revealed increased mRNA levels of TNF-a, spondin-2, and interferon-a2 after 24 h of apigenin treatment in A549 cells, whereas treatment for 48 h led to decreased expression of SPON2 and IFNA2. Apigenin promotes apoptosis in A549 cells by modulating various signaling pathways at different time points. Show less

We investigated whether BMP4, FGF8, and/or WNT3a on neural crest-like cells (NCLC) derived from mouse induced pluripotent stem (miPS) cells will promote differentiation of odontoblasts-like cells. After the miPS cells matured into embryonic body (EB) cells, they were cultured in a neural induction medium to produce NCLC. As the differentiation of NCLC were confirmed by RT-qPCR, they were then disassociated and cultured with a medium containing, BMP4, FGF8, and/or WNT3a for 7 and 14 days. The effect of these stimuli on NCLC were assessed by RT-qPCR, ALP staining, and immunocytochemistry. The cultured EB cells presented a significant increase of Snai1, Slug, and Sox 10 substantiating the differentiation of NCLC. NCLC stimulated with more than two stimuli significantly increased the odontoblast markers Dmp-1, Dspp, Nestin, Alp, and Runx2 expression compared to control with no stimulus. The expression of Dmp-1 and Dspp upregulated more when FGF8 was combined with WNT3a. ALP staining was positive in groups containing BMP4 and fluorescence was observed in immunocytochemistry of the common significant groups between Dmp-1 and Dspp. After stimulation, the cell morphology demonstrated a spindle-shaped cells with long projections resembling odontoblasts. Simultaneous BMP4, FGF8, and WNT3a stimuli significantly differentiated NCLC into odontoblast-like cells. Show less

Apigenin is a flavonoid with antioxidant and anticancer effects. It has been reported that apigenin inhibits proliferation, migration, and invasion and induces apoptosis in cultured lung cancer cells. However, there is little information on the involvement of microRNAs (miRNAs) in its effects. miRNA microarray analysis and polymerase-chain-reaction analysis of miRNAs revealed that treatment of human lung cancer A549 cells with apigenin up-regulated the level of miR-34a-5p. Furthermore, mRNA microarray analysis and the results of three microRNA target prediction tools showed that Snail Family Transcriptional Repressor 1 (SNAI1), which inhibits the induction of apoptosis, had its mRNA expression down-regulated in A549 cells treated with apigenin. Our findings suggest that apigenin might induce apoptosis by down-regulation of SNAI1 through up-regulation of miR-34a-5p in A549 cells. Show less