Involvement of Mitochondrial Mechanisms in the Cytostatic Effect of Desethylamiodarone in B16F10 Melanoma Cells

The Role of the CPT Family in Cancer: Searching for New Therapeutic Strategies

Along with abnormalities in glucose metabolism, disturbances in the balance of lipid catabolism and synthesis have emerged as a new area of cancer metabolism that needs to be studied in depth. Disturbances in lipid metabolic homeostasis, represented by fatty acid oxidation (FAO) imbalance, leading to activation of pro-cancer signals and abnormalities in the expression and activity of related metabolically critical rate-limiting enzymes, have become an important part of metabolic remodeling in cancer. The FAO process is a metabolic pathway that facilitates the breakdown of fatty acids into CO2 and H2O and releases large amounts of energy in the body under aerobic conditions. More and more studies have shown that FAO provides an important energy supply for the development of cancer cells. At the same time, the CPT family, including carnitine palmitoyltransferase 1 (CPT1) and carnitine palmitoyltransferase 2 (CPT2), are key rate-limiting enzymes for FAO that exert a pivotal influence on the genesis and progression of neoplastic growth. Therefore, we look at molecular structural properties of the CPT family, the roles they play in tumorigenesis and development, the target drugs, and the possible regulatory roles of CPTs in energy metabolism reprogramming to help understand the current state of CPT family research and to search for new therapeutic strategies.

Comparison of Mitochondrial and Antineoplastic Effects of Amiodarone and Desethylamiodarone in MDA-MB-231 Cancer Line

Previously, we have demonstrated that amiodarone (AM), a widely used antiarrhythmic drug, and its major metabolite desethylamiodarone (DEA) both affect several mitochondrial processes in isolated heart and liver mitochondria. Also, we have established DEA's antitumor properties in various cancer cell lines and in a rodent metastasis model. In the present study, we compared AM's and DEA's mitochondrial and antineoplastic effects in a human triple-negative breast cancer (TNBC) cell line. Both compounds reduced viability in monolayer and sphere cultures and the invasive growth of the MDA-MB-231 TNBC line by inducing apoptosis. They lowered mitochondrial trans-membrane potential, increased Ca2+ influx, induced mitochondrial permeability transition, and promoted mitochondrial fragmentation. In accordance with their mitochondrial effects, both substances massively decreased overall, and even to a greater extent, mitochondrial ATP production decreased, as determined using a Seahorse live cell respirometer. In all these effects, DEA was more effective than AM, indicating that DEA may have higher potential in the therapy of TNBC than its parent compound.

Renogrit selectively protects against cisplatin-induced injury in human renal tubular cells and in Caenorhabditis elegans by harmonizing apoptosis and mitophagy

Cisplatin-induced nephrotoxicity restricts its clinical use against solid tumors. The present study elucidated the pharmacological effects of Renogrit, a plant-derived prescription medicine, using cisplatin-induced human renal proximal tubular (HK-2) cells and Caenorhabditis elegans. Quantification of phytochemicals in Renogrit was performed on HPTLC and UHPLC platforms. Renogrit was assessed in vitro in HK-2 cells post-exposure to clinically relevant concentration of cisplatin. It was observed that renoprotective properties of Renogrit against cisplatin-induced injury stem from its ability to regulate renal injury markers (KIM-1, NAG levels; NGAL mRNA expression), redox imbalance (ROS generation; GST levels), and mitochondrial dysfunction (mitochondrial membrane potential; SKN-1, HSP-60 expression). Renogrit was also found to modulate apoptosis (EGL-1 mRNA expression; protein levels of p-ERK, p-JNK, p-p38, c-PARP1), necroptosis (intracellular calcium accumulation; RIPK1, RIPK3, MLKL mRNA expression), mitophagy (lysosome population; mRNA expression of PINK1, PDR1; protein levels of p-PINK1, LC3B), and inflammation (IL-1β activity; protein levels of LXR-α). More importantly, Renogrit treatment did not hamper normal anti-proliferative effects of cisplatin as observed from cytotoxicity analysis on MCF-7, A549, SiHa, and T24 human cancer cells. Taken together, Renogrit could be a potential clinical candidate to mitigate cisplatin-induced nephrotoxicity without compromising the anti-neoplastic properties of cisplatin.

Involvement of Mitochondrial Mechanisms and Cyclooxygenase-2 Activation in the Effect of Desethylamiodarone on 4T1 Triple-Negative Breast Cancer Line

Novel compounds significantly interfering with the mitochondrial energy production may have therapeutic value in triple-negative breast cancer (TNBC). This criterion is clearly fulfilled by desethylamiodarone (DEA), which is a major metabolite of amiodarone, a widely used antiarrhythmic drug, since the DEA previously demonstrated anti-neoplastic, anti-metastasizing, and direct mitochondrial effects in B16F10 melanoma cells. Additionally, the more than fifty years of clinical experience with amiodarone should answer most of the safety concerns about DEA. Accordingly, in the present study, we investigated DEA’s potential in TNBC by using a TN and a hormone receptor positive (HR+) BC cell line. DEA reduced the viability, colony formation, and invasive growth of the 4T1 cell line and led to a higher extent of the MCF-7 cell line. It lowered mitochondrial transmembrane potential and induced mitochondrial fragmentation. On the other hand, DEA failed to significantly affect various parameters of the cellular energy metabolism as determined by a Seahorse live cell respirometer. Cyclooxygenase 2 (COX-2), which was upregulated by DEA in the TNBC cell line only, accounted for most of 4T1’s DEA resistance, which was counteracted by the selective COX-2 inhibitor celecoxib. All these data indicate that DEA may have potentiality in the therapy of TNBC.