Anticancer Properties of Platinum Nanoparticles and Retinoic Acid: Combination Therapy for the Treatment of Human Neuroblastoma Cancer

Abstract

Neuroblastoma is the most common extracranial solid tumor in childhood. The different treatments available for neuroblastoma are challenged by high rates of resistance, recurrence, and progression, most notably in advanced cases and highly malignant tumors. Therefore, the development of more targeted therapies, which are biocompatible and without undesired side effects, is highly desirable. The mechanisms of actions of platinum nanoparticles (PtNPs) and retinoic acid (RA) in neuroblastoma have remained unclear. In this study, the anticancer effects of PtNPs and RA on neuroblastoma were assessed. We demonstrated that treatment of SH-SY5Y cells with the combination of PtNPs and RA resulted in improved anticancer effects. The anticancer effects of the two compounds were mediated by cytotoxicity, oxidative stress (OS), mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and apoptosis-associated networks. Cytotoxicity was confirmed by leakage of lactate dehydrogenase (LDH) and intracellular protease, and oxidative stress increased the level of reactive oxygen species (ROS), 4-hydroxynonenal (HNE), malondialdehyde (MDA), and nitric oxide (NO), and protein carbonyl content (PCC). The combination of PtNPs and RA caused mitochondrial dysfunction by decreasing the mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content, number of mitochondria, and expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Endoplasmic reticulum-mediated stress and apoptosis were confirmed by upregulation of protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6), activating transcription factor 4 (ATF4), p53, Bax, and caspase-3 and down regulation of B-cell lymphoma 2 (BCl-2). PtNPs and RA induced apoptosis, and oxidative DNA damage was evident by the accumulation of 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG). Finally, PtNPs and RA increased the differentiation and expression of differentiation markers. Differentiated SH-SY5Y cells pre-treated with PtNPs or RA or the combination of both were more sensitive to the cytotoxic effect of cisplatin than undifferentiated cells. To our knowledge, this is the first study to demonstrate the effect of the combination of PtNPs and RA in neuroblastoma cells. PtNPs may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment. The results of this study provide a rationale for clinical evaluation of the combination of PtNPs and RA for the treatment of children suffering from high-risk neuroblastoma.

Platinum Nanoparticles Enhance Exosome Release in Human Lung Epithelial Adenocarcinoma Cancer Cells (A549): Oxidative Stress and the Ceramide Pathway are Key Players

“…In addition, other characteristic peaks were observed in the spectrum of PtNPs, in agreement with our previous reports. 39 , 41 Sharp peaks at 2,140, 1,640, and 1,025 cm-1, associated with C–H stretching, N–O stretching in the nitro group, and C–C stretching, respectively, have been reported. 39 , 53 The presence of almost all the characteristic peaks of PtNPs indicated the stabilization of nanoparticles by lutein due to the coating of biomolecules.…”

“…Our results are in good agreement with those of biologically synthesized PtNPs using Ocimum sanctum 53 and are consistent with our previous reports. 39 , 41 …”

“…The morphology of the synthesized particles showed a flower-like structure, which is similar to that in previously published reports. 39 , 41 …”

“…ROS production was estimated as described previously. 41 A549 cells were exposed to PtNPs (10 µM) or C6-cer (10 µM) or CSP (10 µM) or GW4869 (20 µM) and the cells were incubated for 24 h. The cells were supplemented with 20 μM of DCFH2-DA and incubation continued for 30 min at 37°C. The fluorescence intensity was determined using a Gemini EM spectrofluorometer.…”

“… 40 Moreover, PtNPs have been shown to induce apoptosis in neuroblastoma cancer cells by triggering loss of cell viability, proliferation, endoplasmic reticulum-mediated stress, and apoptosis by activation of p53, Bax, and caspase-3 and downregulation of BCl-2. 41 However, whether platinum nanoparticles influence exosome biogenesis and release by altering cell survival, cytotoxicity, and apoptosis in human lung epithelial adenocarcinoma cells (A549) remains unclear. In this study, we investigated the platinum nanoparticle-mediated effects on the cellular and exosomal functions of human lung epithelial adenocarcinoma cells (A549) cells cultured in Dulbecco’s modified Eagle medium (DMEM) supplemented with 10% EVs-depleted serum and in serum-free Opti-MEM.…”