An adenosine derivative promotes mitochondrial supercomplexes reorganization and restoration of mitochondria structure and bioenergetics in a diethylnitrosamine-induced hepatocellular carcinoma model

Hepatocellular carcinoma (HCC) progression is associated with dysfunctional mitochondria and bioenergetics impairment. However, no data about the relationship between mitochondrial supercomplexes (hmwSC) formation and ATP production rates in HCC are available. Our group has developed an adenosine derivative, IFC-305, which improves mitochondrial function, and it has been proposed as a therapeutic candidate for HCC. We aimed to determine the role of IFC-305 on both mitochondrial structure and bioenergetics in a sequential cirrhosis-HCC model in rats. Our results showed that IFC-305 administration decreased the number and size of liver tumors, reduced the expression of tumoral markers, and reestablished the typical architecture of the hepatic parenchyma. The livers of treated rats showed a reduction of mitochondria number, recovery of the mtDNA/nDNA ratio, and mitochondrial length. Also, IFC-305 increased cardiolipin and phosphatidylcholine levels and promoted hmwSC reorganization with changes in the expression levels of hmwSC assembly-related genes. IFC-305 in HCC modified the expression of several genes encoding elements of electron transport chain complexes and increased the ATP levels by recovering the complex I, III, and V activity. We propose that IFC-305 restores the mitochondrial bioenergetics in HCC by normalizing the quantity, morphology, and function of mitochondria, possibly as part of its hepatic restorative effect.

TGF-β/SMAD canonical pathway induces the expression of transcriptional cofactor TAZ in liver cancer cells

The TGF-β and Hippo pathways are critical for liver size control, regeneration, and cancer progression. The transcriptional cofactor TAZ, also named WWTR1, is a downstream effector of Hippo pathway and plays a key role in the maintenance of liver physiological functions. However, the up-regulation of TAZ expression has been associated with liver cancer progression. Recent evidence shows crosstalk of TGF-β and Hippo pathways, since TGF-β modulates TAZ expression through different mechanisms in a cellular context-dependent manner but supposedly independent of SMADs. Here, we evaluate the molecular interplay between TGF-β pathway and TAZ expression and observe that TGF-β induces TAZ expression through SMAD canonical pathway in liver cancer HepG2 cells. Therefore, TAZ cofactor is a primary target of TGF-β/SMAD-signaling, one of the pathways altered in liver cancer.