title: Role of Apoptotic Proteins in REC-2006 Mediated Radiation Protection in Hepatoma Cell Lines.
abstract: The present study was carried out to evaluate the role of apoptotic proteins in REC-2006-mediated radiation protection in hepatoma cell lines. REC-2006 treatment 2 h before irradiation strongly inhibited the cleavage of ATM and PARP-1 in HepG2 cells. The expression of nuclear apoptosis inducing factor (AIF) was found to be more inhibited (~17%) in HepG2 cells in REC-2006 + radiation-treated group. More inhibition (~33%) of cytochrome c was observed in HepG2 cells upon REC-2006 treatment 2 h prior irradiation. Similarly, significantly more (P<.05) inhibition of Apaf-1, caspase-9 and caspase-3 was observed in REC-2006 + radition-treated group in HepG2 cells. REC-2006 treatment restored the expression of ICAD in HepG2 cells; however, no restoration was observed in Hep3B cells. Lower nuclear to cytoplasmic CAD ratio was observed in HepG2 cells (~0.6) as compared with Hep3B cells (~1.2) in REC-2006 + radiation-treated group. In conclusion, REC-2006 rendered higher protection in HepG2 cells by inhibiting the expression and translocation of AIF, inhibiting the cleavage of ATM and PARP-1, restoring the expression of ICAD, inhibiting the release of cytochrome c and thus modulating the expression of Apaf-1 caspase-9 and activity of caspase-3.
authors.affiliation: Institute of Nuclear Medicine and Allied Sciences, Delhi, India.
authors.forename: Pankaj Kumar
authors.initials: PK
authors.lastname: Singh
authors.forename: Raj
authors.initials: R
authors.lastname: Kumar
authors.forename: Ashok
authors.initials: A
authors.lastname: Sharma
authors.forename: Rajesh
authors.initials: R
authors.lastname: Arora
authors.forename: Raman
authors.initials: R
authors.lastname: Chawla
authors.forename: Swatantra Kumar
authors.initials: SK
authors.lastname: Jain
authors.forename: Rajendra Prasad
authors.initials: RP
authors.lastname: Tripathi
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Sharma