The transcript NR 134251.1 of lncRNA APTR with an opposite function to all transcripts inhibits proliferation and induces apoptosis by regulating proliferation and apoptosis-related genes.

Arsenic (As) exposure has been a global public health concern for hundreds of millions worldwide. LncRNA APTR (Alu-mediated p21 transcriptional regulator) plays an essential role in tumor growth and development. However, its function in arsenic-induced toxicological responses is still unknown. In this study, we found that the expressions of all transcripts and the transcript NR 134251.1 of APTR were increased in a dose-dependent manner in 16HBE cells treated with sodium arsenite (NaAsO). Silencing the transcript NR 134251.1 of APTR inhibited cell proliferation and induced apoptosis. However, silencing all transcripts of APTR had the opposite function to the transcript NR 134251.1. Then we examined the protein level of the proliferation and apoptosis-related genes after silencing the transcript NR 134251.1 of APTR. The results showed that silencing the transcript NR 134251.1 of APTR up-regulated the expression of transcription factor E2F1 and regulated its downstream genes involved in proliferation and apoptosis, including p53, phospho-p53-S392, phospho-p53-T55, p21, Cyclin D1, PUMA, Fas, Bim, BIK, Caspase-3, Caspase-7, and Cyt-c. In conclusion, arsenic induced APTR expression and the transcript NR 134251.1 of APTR have an opposite function to all transcripts, providing a theoretical basis for the prevention and treatment of arsenic exposure.