Pseudogenes in the carcinogenesis: epithelial-to-mesenchymal transition process and cancer initiating cells.

Initially, pseudogenes were considered to be "junk DNA", and their biological role was unclear. However, some of the pseudogenes are engaged in the process of cancerogenesis and perform essential functions in competing for endogenous ribonucleic acid (ceRNA) networks and competing for RNA binding proteins (RBPs). They either positively or negatively regulate gene expression and act as suppressive and oncogenic transcripts. In this review, we look at some of the pseudogenes that play a role in the epithelial-to-mesenchymal transition (EMT) process and the maintenance of cancer-initiating cells (CIC), which are essential in understanding cancer development and progression metastasis and resistance to commonly used therapies. The group of discussed pseudogenes consists of CHIAP2, PTENP1, SUMO1P3, NANOGP8, OCT4-PG1/4, or HMGA1-P6, which are connected with different molecular pathways. Moreover, we discussed pseudogenes as potential diagnostic molecules that can be used as a new class of biomarkers. This potential usage may be valuable for oncology and personalized medicine in the future.