Moreover, CHIR enhanced upregulation of or genes, but to our surprise the knockdown had no visible influence within the expression of the gene strongly inhibited by CHIR-expression nor caspase-3 activation

Moreover, CHIR enhanced upregulation of or genes, but to our surprise the knockdown had no visible influence within the expression of the gene strongly inhibited by CHIR-expression nor caspase-3 activation. radiation, oxidative stress, oncogene activation. However, the protein is also triggered by stress factors, associated with anticancer therapy, e.g., high-dose ionizing radiation, chemotherapeutic DNA-damaging providers. These p53 activators are not found in the natural environment but they exploit the ability of p53 to induce cell cycle arrest or apoptosis. There are also experimental anticancer drugs (e.g., nutlin-3a), which were designed specifically to activate p53 by antagonizing MDM2 protein, which is unfavorable regulator of p53 [1]. We found that ONO-AE3-208 two anticancer brokers actinomycin D and nutlin-3a acting together (A + N) synergize in activation of p53 protein and consequently, they synergize in stimulation of p53-regulated genes [2]. The strong activation of p53 by these brokers allowed to identify genes, whose regulation by p53 was not observed before, e.g., the genes coding for proteins involved in innate immunity: ([3,4]. The synergy between actinomycin D and nutlin-3a in activation of some genes is usually exceptionally strong. This group includes and as well as the aforementioned and [3,4,5]. codes for caspase-1, an innate immunity protein, which induces programmed cell death called pyroptosis associated with secretion of pro-inflammatory cytokines-interleukin-1 and interleukin-18 [6]. gene directs the production of long non-coding RNA molecules with anti-apoptotic activity [7]. Unexpectedly, we found that in A549 lung cancer cell line the drug combination A + N induced the expression of several ONO-AE3-208 elements of a signaling pathway encompassing TREM2 (a receptor), TYROBP (a co-receptor), SYK (a kinase) and BLNK (an adaptor protein) [3]. This signaling pathway ONO-AE3-208 is found principally in cells involved in innate immunity, e.g., microglial cells [8], hence, its appearance in lung cancer cells exposed to A + N was very surprising. Interestingly, the induction of all these proteins was significantly attenuated by sub-micromolar concentration of CHIR-98014 (in the following part abbreviated to CHIR), which is considered as a specific inhibitor of glycogen synthase kinase 3, and isoforms coded by and genes, respectively [9,10]. This observation suggested that GSK-3 is usually indispensable for activation of p53 and stimulation of some of its target genes. This enzyme, not only regulates the synthesis of glycogen, but also regulates the plethora of other cellular processes, hence its name may be misleading suggesting unique role in cellular metabolism. GSK-3 influences embryonic development, neuronal function, cell proliferation ONO-AE3-208 and differentiation, apoptosis, inflammation and immune response [10]. The p53 can be activated by phosphorylation catalyzed by GSK-3 [11], hence our selection of CHIR to test the role of this kinase in activation of p53 brought on by A + N treatment. In the current project we decided to perform global search for genes regulated by A + N as well as by CHIR. We started from transcriptome analysis of cells in control ONO-AE3-208 conditions or exposed to MAPKAP1 A + N, to A + N + CHIR or to CHIR alone. In this way we identified dozens of candidate p53-target genes and found what genes upregulated by A + N are additionally modulated by GSK-3 kinase inhibitor. Based on RNA-Seq data and on experiments with designed p53-deficient cells, we found that p53 participates in upregulation of two genes-and employed by us earlier [2,3,4,5]. Moreover, to the best of our knowledge, the transcriptomic data on p53-target genes in A549 cell line were not published [12]. Unexpectedly, in the course of our recent research we found that in cancer cells, strongly activated p53 was able to induce expression of many genes, which were known to be.