Figure 8. MDA-MB-231 cells overexpressing CTGF display the induction of autophagy/mitophagy, with HIF-1α activation. To study if CTGF expression has any compartment-specific effects, CTGF was overexpressed in MDA-MB-231 cells. (A) Immunoblot analysis was performed on total protein lysates to confirm CTGF overexpression. (B, C) MDA-MB-231 cells overexpressing CTGF show activation of an autophagy/mitophagy program. Immunoblot analysis on CTGF- and control-MDA-MB-231 cells reveals that CTGF significantly increases the expression levels of several proteins involved in mitophagy (BNIP3) and autophagy (Lamp-1, Beclin-1, cathepsin B and LC3) under (B) basal condition or (C) after 2h of nutrient starvation. (D) Immunblot analysis of total protein lysates from control and CTGF-MDA-MB-231 cells shows that CTGF expression induces the activation of HIF-1α in MDA-MB-231 cells. Two exposures are shown. For all, β-actin was used as control for equal protein loading. (E) ROS assay performed on control- and CTGF-MDA-MB-231 cells reveals that CTGF expression induces a 20% increase in ROS production.