CO2 pneumoperitoneum effects on proliferation and apoptosis in two different neuroblastoma cell lines

Purpose: The proto-oncogene MYCN is considered a transcription factor involved in the regulation of neuroblastoma (NB) cell biology. Since minimally invasive-surgery represents a debated treatment of NB, we investigated CO2 effects on proliferative activity and apoptotic pathway in two NB cell lines, SH-SY5Y (MYCN-non-amplified) and IMR-32 (MYCN-amplified). Methods: SH-SY5Y and IMR-32 were exposed to CO2 (100%) at a pressure of 15 mmHg for 4 h and then moved to normal condition for 24 h. Cell proliferation, caspase 3 activity and transcript levels of BAX, BCL-2, cyclin B, cyclin D and MMP-2 were evaluated. Results: CO2 exposure caused a decrease in cell proliferation associated to increases in BAX/BCL-2 ratio and caspase 3 activity in SH-SY5Y, while opposite effects have been found in IMR-32. CO2 exposure induced a decrease of cyclin B1 in SH-SY5Y, while an increase in cyclin B1 and D1 was observed in IMR-32. A slight up-regulation of MMP-2 expression in SH-SY5Y and a significant increase of 2.2 folds in IMR-32 was observed (p < 0.05). Conclusions: Our results suggest that CO2 exposure may cause different effects on various NB cell lines, likely due to MYCN amplification status. Further in vitro and in vivo studies are needed to highlight the role of laparoscopy on NB behaviour.