Poly (I:C) transfection induces mitochondrial-mediated apoptosis in cervical cancer.

Abstract

Polyinosinic acid:polycytidylic acid, known as poly (I:C), is an analogue of double‑stranded RNA, which exhibits direct antitumor effects against several types of cancer. The present study aimed to evaluate the role of poly (I:C) in the apoptosis of cervical cancer cells. The HeLa human cervical cancer cell line was used in the present study, and cell apoptosis was determined following poly (I:C) transfection. Furthermore, the mRNA levels of interferon (IFN)‑β, the production of reactive oxygen species (ROS), DNA damage, mitochondrial membrane potential (∆Ψm) and the release of cytochrome c, as well as caspase activation, were determined. The effect of IFN‑β on poly (I:C) transfection‑mediated apoptosis was also examined by IFN‑β knockdown. The results showed that poly (I:C) transfection markedly induced HeLa apoptosis, increased the protein levels of pro‑apoptotic B cell lymphoma‑2 (Bcl‑2)‑associated X protein (Bax) and BH3 interacting‑domain death agonist (Bid), and suppressed the protein expression levels of anti‑apoptotic Bcl‑2 and Survivin. However, poly (I:C) transfection increased the mRNA levels of IFN‑β, induced ROS production and increased the levels of phosphorylated γH2A.X, an indicator of DNA damage. In addition, poly (I:C) transfection decreased ∆Ψm, triggered the release of cytochrome c from the mitochondria to the cytosol, and induced caspase‑9 and ‑3 activation. IFN‑β knockdown decreased the poly (I:C)‑induced production of ROS and DNA damage, restored ∆Ψm and cytochrome c release, and suppressed caspase‑9 and ‑3 activation, thereby suppressing poly (I:C)‑mediated apoptosis in the HeLa cells. Together, the results of the present study demonstrated that poly (I:C) transfection induced IFN‑β, contributing to ROS production, DNA damage, and caspase‑9 and ‑3 activation in the HeLa cervical cancer cell line, leading to mitochondrial‑mediated apoptosis.