The NF-kB-dependent signaling pathways are essential components of cellular response to stress. Mammalian family of NF-kB consists of five NF-kB/Rel proteins, which are subunits of the NF-kB transcription factor, and four IkB proteins, which are their specific inhibitors. Activation of NF-kB requires degradation of IkB, which allows nuclear translocation of NF-kB and its binding to cisacting DNA regulatory elements. NF-kB transcription factors regulate expression of numerous genes, which are involved in cell proliferation, apoptosis, immune response and inflammatory response.

MicroRNAs (miRNAs) constitute a group of single-stranded, noncoding RNAs that regulate the expression of structural genes on post-transcriptional level. miRNAs are transcribed as several hundred- nucleotide pri-miRNAs. The mature, active form is only 21–23 nucleotides long and it binds target mRNAs containing antisense sequences. miRNA can either catalyze cleavage of mRNA that are perfectly base- paired to its sequence, or inhibit the translation of mRNAs that form an imperfect complex with the miRNA. Hundreds of miRNAs are described to date, which populate the genomes of plants and animals.