The effects of Nutlin-3 on morphology, cellular proliferation, and apoptosis in rat primary mesenchymal stem cells

Nutlin-3 is a powerful antagonist of murine double minute 2/p53 interaction demonstrating promising therapeutic anticancer activity, which has not been clinically approved yet. Mesenchymal stem cells (MSCs) are an important part of the bone marrow niche and support regeneration and proliferation of hematopoietic stem cells after exposure to myelotoxic anticancer agents; however, the effect of Nutlin-3 compounds on MSCs themselves remains to be elucidated.

Rat-derived bone marrow-derived MSCs (BMSCs) were cultured and treated with different concentrations (5, 10, 25, 50, and 100 μM) and times (24, 48, and 72 hr) of Nutlin-3. The microculture tetrazolium test, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and propidium iodide and annexin-V assays, and quantitative real-time reverse-transcription polymerase chain reaction were performed to assess the effects of Nutlin-3 on the cell viability, proliferation, and apoptosis in BMSCs.

The viability of BMSCs in the treated cells with concentrations of 100 μM at 24 hr, 50 and 100 μM at 48 hr, and in all concentrations at 72 hr was significantly (p < 0.05) low. The apoptotic index showed that the TUNEL-positive BMSCs were significantly higher in concentrations of 25 and 50 μM in comparison to control group ( p < 0.05) and augmented in a dose-dependent manner. Annexin-V-PI staining showed after 72 hr of incubation, there was a slight dose-dependent increase in total apoptotic cells at 10 and 25 μM of Nutlin-3, but a massive significant increase at 50 μM.

Here, we show that rat BMSCs are relatively resistant to Nutlin-3; however, further in vivo data with long-term exposure may help to corroborate our findings.