Induction of apoptosis is directly correlated with the biological effectiveness of ionizing radiation (IR). Accordingly, we investigated the efficacy ofneem leaf extract (NLE) on IR-associated apoptotic transcriptional modulation and cell death in neuroblastoma (NB). Materials and Methods: NB xenografts exposed to single dose (SDR, 10 Gy) or fractionated (FIR, 2 Gy/dx5d) with or without NLE were examined for transcriptional activation of 84 apoptotic pathway genes using quantitative polymerase chain reaction. Apoptosis was measured using TdT nick-end labeling. Results: FIR induced 55 and suppressed 10 genes, while SDR induced 49 and suppressed 5 genes. Of these, 46 and 4 genes were commonly up/down-regulated after FIR and SDR. NLE inhibited IR-induced NAIP, BIRC6, BIRC8, NOL3 and enhanced BAK1, BAX, BCL10, CASP1, CASP10 CARD8 and CRADD. Furthermore, NLE conferred FIR- and SDR-induced cell death. Conclusion: These data imply that NLE may exert radiosensitization by activating pro-apoptotic signaling and negating survival signaling and may thus potentiate radiotherapy in NB.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Jan 1 2011|
- Neem leaf extract
- Transcriptional response
ASJC Scopus subject areas
- Cancer Research