Effect of napabucasin and doxorubicin via the Jak2/Stat3 signaling pathway in suppressing the proliferation of neuroblastoma cells.

Napabucasin (NP) is a natural compound that can suppress cancer cell proliferation and cell cycle by inhibition of the signal transducer and activator of transcription 3 (STAT3) gene. We examined the effects of NP on the proliferation and invasion of neuroblastoma cells (SH-SY5Y). Human neuroblastoma SH-SY5Y cell line was used in this study. NP was administered to groups at the doses of 0.3-1 µM. Cell viability was analyzed by MTT assay. Real-time quantitative reverse transcription polymerase chain reaction and western blot analysis assessed the expressions of interleukin (IL)-6 dependent Jak2/Stat3 signaling pathway. The MTT cell viability method was applied to determine the antagonistic-synergistic effects and inhibitory concentration (IC50) doses of doxorubicin (DX) and NP. It was determined that 0.3-1 µM doses of NP killed the cells almost completely after 48 hours, and also that Jak2/Stat3 expressions decreased dose-dependently via IL-6. At the protein level, NP and DX were found to reduce Jak2 and Stat3 levels. NP showed that it suppresses the proliferation of neuroblastoma cells. Due to its inhibitory effect on Jak2 and Stat3, it can be used to prevent invasion of SH-SY5Y cells. NP, which can inactivate Jak2/Stat3, can be used as a treatment agent by combining with DX in proliferation pathway in neuroblastoma.