Nanog Homeobox Pseudogene 8 (NANOGP8) is a transcribed retrogene derived from the Nanog homeobox gene. The Nanog gene is crucial for maintaining the pluripotency of embryonic stem cells, and its pseudogenes have been extensively studied for their roles in various biological processes, including cancer cell proliferation .
NANOGP8 is a human-specific retropseudogene that arose through retrotransposition from its parent gene, NANOG. This process involves the reverse transcription of RNA molecules followed by the insertion of DNA copies into the genome. NANOGP8 is unique to humans and is not found in the genomes of other primates, such as chimpanzees .
The evolutionary origin of NANOGP8 is estimated to be between 0.9 to 2.5 million years ago. It arose from a derived variant allele of NANOG containing a 22-nucleotide pair deletion in the 3′ UTR. This variant has remained polymorphic in modern humans .
NANOGP8 is predominantly expressed in cancer cells, where its protein product is tumorigenic. In vitro studies using a recombinant protein have shown that NANOGP8 localizes to the nucleus and can promote cell proliferation, similar to the Nanog protein . This suggests that NANOGP8 may play a role in the reprogramming of cancer cells and contribute to the higher genetic predisposition for cancer in humans compared to other primates .