Ionizing Radiation Upregulates Glutamine Metabolism and Induces Cell Death via Accumulation of Reactive Oxygen Species

Figure 5

Inhibition of mitophagy promotes ionizing radiation-induced cell death. MCF-7 and HCT-116 cells were irradiated with 4 Gy and/or 8 Gy X-rays. Mdivi-1 decreased X-ray-induced expression of mitophagy-related proteins (a, b) and the mitochondrial membrane potential (c). Mdivi-1 led to increased ROS accumulation (d) and increased DNA damage (e, f). Silencing the Parkin gene (g) led to increased ROS accumulation induced by X-rays (h). Mdivi-1 or silencing the Parkin gene enhanced cell death induced by X-rays (i, j) and reduced clone formation (k). of triplicate assessments, one-way ANOVA with post hoc Dunnett test, , , and (a–k).

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)