Citation
- Authors: Arena A. et al.
- Year: 2022
- Journal: Biochim Biophys Acta Mol Cell Res 1869 119168
- Applications: in vitro / siRNA / INTERFERin
- Cell type: BC-3
Method
BC3 cells were seeded into 6-well plates at a density of 1 × 106 cells/well and transfected with Myc siRNA (sicMyc, Santa Cruz Biotechnology, sc-29226) or p21 siRNA (sip21, Santa Cruz Biotechnology, sc-29427) for knockdown using INTERFERin® (Polyplus-transfection) according to the manufacturer's instructions. Control siRNA-A (scr, Santa Cruz Biotechnology sc-37,007) was used as a scrambled control.
After 48 h of transfection, the cells were treated as above reported with AZD2461 (40 μM) and UCN-01 (100 nM) for 24 h. At the end, a Trypan blue assay was performed and the cells were recovered for further analysis.
Abstract
The induction of DNA damage together with the interference with DNA repair represents a promising strategy in cancer treatment. Here we show that the PARP-1/2/3 inhibitor AZD2461 in combination with the CHK1 inhibitor UCN-01 altered the DNA damage response and reduced cell proliferation in PEL cells, an aggressive B cell lymphoma highly resistant to chemotherapies. AZD2461/UCN-01 combination activated p53/p21 and downregulated c-Myc in these cells, leading to a reduced expression level of RAD51, molecule involved in DNA repair. The effect of AZD2461/UCN-01 on c-Myc and p53/p21 was inter-dependent and, besides impairing cell proliferation, contributed to the activation of the replicative cycle of KSHV, carried in a latent state in PEL cells. Finally, we found that the pharmacological or genetic inhibition of p21 counteracted the viral lytic cycle activation and further reduced PEL cell proliferation, suggesting that it could induce a double beneficial effect in this setting. This study unveils that, therapeutic approaches, based on the induction of DNA damage and the reduction of DNA repair, could be used to successfully treat this malignant lymphoma.