Transcriptomic analyses revealed hundreds of p53-regulated genes, however these studies used a limited number of cell lines and p53-activating agents. Therefore, we searched for candidate p53-target genes by employing stress factors and cell lines never used in high-throughput search for p53-regulated genes. We performed RNA-Seq on A549 cells exposed either to camptothecin, actinomycin D, nutlin-3a or to a combination of actinomycin D and nutlin-3a (A+N). The latter two substances synergize in activation of selected p53-target genes. Similar analysis was performed on other cell lines (U-2 OS, NCI-H460, A375) exposed to A+N. Mass spectrometry was employed to identify proteins in cell lysates or those secreted to the medium of A549 cells in control conditions or treated with A+N. Expression of selected genes strongly upregulated by A+N or camptothecin was examined by RT-PCR in p53-deficient cells and their controls. We found that p53 participates in upregulation of: ACP5, APOL3, CDH3, CIBAR2, CRABP2, CTHRC1, CTSH, FAM13C, FBXO2, FRMD8, FRZB, GAST, ICOSLG, KANK3, KCNK6, KLRG2, MAFB, MR1, NDRG4, PTAFR, RETSAT, TMEM52, TNFRSF14, TRANK1, TYSND1, WFDC2, WFDC5, WNT4 genes. Twelve of their proteins were detected in the secretome and/or proteome of treated cells. Our data generate new hypotheses concerning functioning of p53 tumor suppressor.