Resveratrol is a plant phenolic phytoalexin that has been reported to have antitumor properties in several types of cancers. In particular, several studies have suggested that resveratrol exerts antiproliferative effects against A549 human non-small cell lung cancer cells; however, its mechanism of action remains incompletely understood. Deregulation of microRNAs (miRNAs), a class of small, noncoding, regulatory RNA molecules involved in gene expression, is strongly correlated with lung cancer. In this study, we demonstrated that resveratrol treatment altered miRNA expression in A549 cells. Using microarray analysis, we identified 71 miRNAs exhibiting greater than 2-fold expression changes in resveratrol-treated cells relative to their expression levels in untreated cells. Furthermore, we identified target genes related to apoptosis, cell cycle regulation, cell proliferation, and differentiation using a miRNA target-prediction program. In conclusion, our data demonstrate that resveratrol induces considerable changes in the miRNA expression profiles of A549 cells, suggesting a novel approach for studying the anticancer mechanisms of resveratrol.

Ionizing radiation (IR) is widely used in cancer treatment and in biological studies. It disrupts cellular homeostasis through multiple mechanisms including changes of the expression profile of genes. Although microRNAs (miRNAs) have recently been recognized as important post-transcriptional regulators and are involved in various biological processes, whether miRNAs play any roles in the cellular response to IR, is not well examined. We investigated the profile of miRNA expression following IR in the human lung carcinoma cell line A549, and the expression profiles of IR-responsive miRNAs were confirmed by qRT-PCR. The target mRNAs of IR-responsive miRNAs were predicted with a target prediction tool. Microarray analysis identified 12 and 18 miRNAs in 20- and 40 Gy-exposed A549 cells, respectively, that exhibited more than 2-fold changes in their expression levels. Of these, four were changed in only 20-Gy-treated cells, ten only in 40-Gy-treated cells, and eight miRNAs were found to change after both treatments. qRT-PCR analysis of a subset of the miRNAs showed patterns of regulation as the microarray data, although the magnitude of the changes differed in the two data sets. Target prediction for IR-responsive miRNAs suggests that they target genes related to apoptosis, regulation of cell cycle, and DNA damage and repair. Taken together, these data suggest that miRNA expression is affected by radiation, and they may be involved in the regulation of radiation responses.

Accumulating evidence indicates that reactive oxygen species (ROS) are an important etiological factor for the induction of dermal papilla cell senescence and hair loss, which is also known alopecia. Arctiin is an active lignin isolated from Arctium lappa and has anti-inflammation, anti-microbial, and anti-carcinogenic effects. In the present study, we found that arctiin exerts anti-oxidative effects on human hair dermal papilla cells (HHDPCs). To better understand the mechanism, we analyzed the level of hydrogen peroxide (H₂O₂)-induced cytotoxicity, cell death, ROS production and senescence after arctiin pretreatment of HHDPCs. The results showed that arctiin pretreatment significantly inhibited the H₂O₂-induced reduction in cell viability. Moreover, H₂O₂-induced sub-G1 phase accumulation and G2 cell cycle arrest were also downregulated by arctiin pretreatment. Interestingly, the increase in intracellular ROS mediated by H₂O₂ was drastically decreased in HHDPCs cultured in the presence of arctiin. This effect was confirmed by senescence associated-beta galactosidase (SA-β-gal) assay results; we found that arctiin pretreatment impaired H₂O₂-induced senescence in HHDPCs. Using microRNA (miRNA) microarray and bioinformatic analysis, we showed that this anti-oxidative effect of arctiin in HHDPCs was related with mitogen-activated protein kinase (MAPK) and Wnt signaling pathways. Taken together, our data suggest that arctiin has a protective effect on ROS-induced cell dysfunction in HHDPCs and may therefore be useful for alopecia prevention and treatment strategies.

Clinical evidence has demonstrated that the accumulation of 5α-dihydrotestosterone (DHT) in dermal papilla cells (DPCs) is implicated in androgenetic alopecia. Whether this accumulation in DHT may have direct cellular effects leading to androgenetic alopecia remains to be elucidated. The present study aimed to determine whether DHT affects cell growth, cell cycle arrest, cell death, senescence and the induction of reactive oxygen species (ROS), and whether these effects are mediated by microRNA (miRNA)-dependent mechanisms. The cell viability and cell cycle were determined, levels of ROS were examined and senescence-associated β-galactosidase assays were performed in normal human DPCs (nHDPCs). Furthermore, miRNA expression profiling was performed using an miRNA microarray to determine whether changes in the expression levels of miRNA were associated with the cellular effects of DHT. The results revealed that DHT decreased cell growth by inducing cell death and G2 cell cycle arrest, and by increasing the production of ROS and senescence in the nHDPCs. In addition, 55 miRNAs were upregulated and 6 miRNAs were downregulated in the DHT-treated nHDPCs. Bioinformatic analysis demonstrated that the putative target genes of these upregulated and downregulated miRNAs were involved in cell growth, cell cycle arrest, cell death, senescence and the production of ROS. Specifically, the target genes of five highly upregulated and downregulated miRNAs were identified and were associated with the aforementioned effects of DHT. These results demonstrated that the expression of miRNA was altered in the DHT-treated nHDPCs and suggest the potential mechanisms of DHT-induced cell growth repression, cell cycle arrest, cell death, senescence and induction of ROS.