Human NYNRIN Knockout Cell Line-PC3

NYNRIN (NYN domain and retroviral integrase) is a gene that may have played an important role in the evolutionary emergence of placental structures in therian mammals. NYNRIN is derived from the fusion of a gene containing KH and NYN domains (KHNYN) with fragments from the Ty3/Gypsy retrotransposon, including the reverse transcriptase ribonuclease H (RNase H) domain and the integrase (INT) domain. The gene appeared in the therian lineage, a critical period marked by the emergence of the placenta, which contributed to the evolutionary success of therian mammals. NYNRIN expression was found to be consistently elevated in placental tissues of therian mammals, with some exceptions, such as the Tamal kangaroo, which may be attributed to gaps in the data or the ambiguous invasive nature of the placental type in this species. Functional analysis using siRNA specifically targeting NYNRIN in a human trophoblast cell line revealed its key role in trophoblast invasion. Knockdown of NYNRIN significantly inhibited the invasive ability of HTR8/SVneo cells, while this behavior was not observed with knockdown of its non-retroviral-derived homolog KHNYN, suggesting that there was a significant evolutionary functional divergence after the gene fusion, with NYNRIN acquiring and refining a role that is indispensable for placental function.