IL-2 induces apoptosis, increases the production and expression of cytochrome-C and inhibits COX IV in cervical cancer cells

It is known that cervical cancer cells express IL-2 receptor (IL-2R) and those high doses induce cell death. To identify the type of cell death two cervical cancer cell lines, CALO and INBL, were cultured with 100 IU/ml of IL-2. Our results showed the presence of apoptotic cell death by the significant expression of phosphatidylserine on the external surface of cellular membranes, the presence of a typical DNA fragmentation and the activation of caspase 3. We also observed that the expression of COX I, COX II and COX III was not significantly altered while that of COX IV was completely inhibited. An increased expression of cytochrome-C by confocal microscopy was observed. Finally, we speculate that the clinical effect and toxicities of IL-2 used in cancer therapies is mostly due to its apoptotic effect on the cancer cells themselves rather than, as thought, the cytotoxic contribution of leukocytes.