Novel zinc oxide nanoparticles of Teucrium polium suppress the malignant progression of gastric cancer cells through modulating apoptotic signaling pathways and epithelial to mesenchymal transition

Cytotoxic effects of NIR responsive chitosan-polymersome layer coated melatonin-upconversion nanoparticles on HGC27 and AGS gastric cancer cells: Role of the ROS/PI3K/Akt/mTOR signaling pathway

In this study, a formulation of NaGdF4:Tm/Er@NaGdF4 (core@shell) UCNPs loaded with melatonin drug was synthesized. The novel melatonin-loaded UCNPs were then encapsulated within NIR-responsive biopolymeric chitosan (CS) based polymersome and investigated against gastric cancer (HGC27 & AGS) cells. The photolysis of the ONB moiety and disruption of the disulfide linkage in the polymersome induced by NIR light facilitated by the NaGdF4:Tm/Er@NaGdF4 UCNPs and GSH results in an increased release of melatonin drug. The DLS and zeta potential measurements exhibit a reduced particle size (21.9 ± 3.56 nm) and a low zeta potential (17.91 mV). Furthermore, drug release profiles demonstrated superior melatonin drug release (79.78 %) at pH 5.0 for CS-polymersome-coated melatonin-UCNPs resembling the Hixson-Crowell model. Remarkably, CS-polymersome-coated melatonin-UCNPs exhibit excellent anti-proliferative properties for HGC27 (IC50 = 0.096 μM) and AGS (IC50 = 0.16 μM) cancer cells. The flow cytometry data demonstrate a significant elevation in ROS levels which promoted cell death in both HGC-27 and AGS cells. The observed cell mortality in HGC-27 and AGS cells is primarily caused by the destruction of the nucleus, mtDNA, rupture of disulfide (R-S-S-R) bonds, and nuclear DNA. Contrarily, L929 and HUVECs cells incubated with CS-polymersome coated melatonin-UCNPs (100 μg/mL) reveal a notable cell viability of 88.7 % and 93 % indicating superior biocompatibility. The western blotting analysis revealed the induction of autophagy by CS-polymersome-coated melatonin-UCNPs which subsequently led to apoptosis by regulating the ROS/PI3K/Akt/mTOR molecular signaling pathway.

Zinc Oxide Nanoparticles and Cancer Chemotherapy: Helpful Tools for Enhancing Chemo-sensitivity and Reducing Side Effects?

Cancer chemotherapy is still a serious challenge. Chemo-resistance and destructive side effects of chemotherapy drugs are the most critical limitations of chemotherapy. Chemo-resistance is the leading cause of chemotherapy failure. Chemo-resistance, which refers to the resistance of cancer cells to the anticancer effects of chemotherapy drugs, is caused by various reasons. Among the most important of these reasons is the increase in the efflux of chemotherapy drugs due to the rise in the expression and activity of ABC transporters, the weakening of apoptosis, and the strengthening of stemness. In the last decade, a significant number of studies focused on the application of nanotechnology in cancer treatment. Considering the anti-cancer properties of zinc, zinc oxide nanoparticles have received much attention in recent years. Some studies have indicated that zinc oxide nanoparticles can target the critical mechanisms of cancer chemo-resistance and enhance the effectiveness of chemotherapy drugs. These studies have shown that zinc oxide nanoparticles can reduce the activity of ABC transporters, increase DNA damage and apoptosis, and attenuate stemness in cancer cells, leading to enhanced chemo-sensitivity. Some other studies have also shown that zinc oxide nanoparticles in low doses can be helpful in minimizing the harmful side effects of chemotherapy drugs. In this article, after a brief overview of the mechanisms of chemo-resistance and anticancer effects of zinc, we will review all these studies in detail.

The role of metal ions in the occurrence, progression, drug resistance, and biological characteristics of gastric cancer

Metal ions exert pivotal functions within the human body, encompassing essential roles in upholding cell structure, gene expression regulation, and catalytic enzyme activity. Additionally, they significantly influence various pathways implicated in divergent mechanisms of cell death. Among the prevailing malignant tumors of the digestive tract worldwide, gastric cancer stands prominent, exhibiting persistent high mortality rates. A compelling body of evidence reveals conspicuous ion irregularities in tumor tissues, encompassing gastric cancer. Notably, metal ions have been observed to elicit distinct contributions to the progression, drug resistance, and biological attributes of gastric cancer. This review consolidates pertinent literature on the involvement of metal ions in the etiology and advancement of gastric cancer. Particular attention is directed towards metal ions, namely, Na, K, Mg, Ca, Fe, Cu, Zn, and Mn, elucidating their roles in the initiation and progression of gastric cancer, cellular demise processes, drug resistance phenomena, and therapeutic approaches.