Dinuclear orthometallated gold(I)-gold(III) anticancer complexes with potent in vivo activity through an ROS-dependent mechanism

Gold(I) complexes of the type [AuL{κC-2-C6H4P(S)Ph2}] [L = PTA, PPh3, PPh2(C6H4-3-SO3Na) and PPh2(2-py)]: Synthesis, characterisation, crystal structures, and In Vitro and In Vivo anticancer properties

Four new mononuclear gold (I) compounds of the type [AuL{κC-2-C6H4P(S)Ph2}] {L = PTA (1), PPh3 (2), PPh2(C6H4-3-SO3Na) (3), and PPh2(2-py) (4)} were prepared by scission of the dinuclear compound [Au2{μ-2-C6H4P(S)Ph2}2] by L or via a transmetalation reaction using the organotin reagent 2-Me3SnC6H4P(S)Ph2 and a suitable gold halide precursor. The cytotoxic potential of complexes 1-4 was evaluated against four human cancer cell lines of diverse cellular origin: cervical (HeLa), prostate (PC-3), non-small cell lung adenocarcinoma (A549), and fibrosarcoma (HT-1080). The in vitro cytotoxicity results showed that 1 demonstrated exceptional anticancer activity with IC50 values ranging from 0.08 to 3.5 μM. Complex 3, which contains a sulfonated triphenyl phosphine ligand, displayed the weakest anticancer activity with IC50 values ranging from 3.1 to >50 μM. When compared to the standard chemotherapeutic drug cisplatin, 1 displayed approximately 27-fold greater cytotoxic activity against cervical cancer cells and 3.5- and 7.5-fold greater activities against prostate and fibrosarcoma cancer cells, respectively. Additionally, 1 exhibited 3-fold selectivity for cervical cancer cells compared to non-cancerous HEK-293 cells. Mechanistic investigations revealed that 1 induced apoptosis, which was associated with elevated reactive oxygen species (ROS) and inhibition of the intracellular enzyme thioredoxin reductase. Furthermore, 1 exhibited notable antiangiogenic characteristics in an in vivo model using transgenic zebrafish Tg(fli1a:EGFP). In vivo studies using mouse xenograft models showed that complex 1 displayed superior inhibition of tumour growth (82 %) compared to the clinical drug cisplatin (29 %). Overall, these results highlight the potential of gold (I) compounds as novel antitumour agents.

A review on metal complexes and its anti-cancer activities: Recent updates from in vivo studies

Research into cancer therapeutics has uncovered various potential medications based on metal-containing scaffolds after the discovery and clinical applications of cisplatin as an anti-cancer agent. This has resulted in many metallodrugs that can be put into medical applications. These metallodrugs have a wider variety of functions and mechanisms of action than pure organic molecules. Although platinum-based medicines are very efficient anti-cancer agents, they are often accompanied by significant side effects and toxicity and are limited by resistance. Some of the most studied and developed alternatives to platinum-based anti-cancer medications include metallodrugs based on ruthenium, gold, copper, iridium, and osmium, which showed effectiveness against many cancer cell lines. These metal-based medicines represent an exciting new category of potential cancer treatments and sparked a renewed interest in the search for effective anti-cancer therapies. Despite the widespread development of metal complexes touted as powerful and promising in vitro anti-cancer therapeutics, only a small percentage of these compounds have shown their worth in vivo models. Metallodrugs, which are more effective and less toxic than platinum-based drugs and can treat drug-resistant cancer cells, are the focus of this review. Here, we highlighted some of the most recently developed Pt, Ru, Au, Cu, Ir, and Os complexes that have shown significant in vivo antitumor properties between 2017 and 2023.

Organometallic gold(I) and gold(III) complexes for lung cancer treatment

Metal compounds, especially gold complexes, have recently gained increasing attention as possible lung cancer therapeutics. Some gold complexes display not only excellent activity in cisplatin-sensitive lung cancer but also in cisplatin-resistant lung cancer, revealing promising prospects in the development of novel treatments for lung cancer. This review summarizes examples of anticancer gold(I) and gold (III) complexes for lung cancer treatment, including mechanisms of action and approaches adopted to improve their efficiency. Several excellent examples of gold complexes against lung cancer are highlighted.

Recent development of gold(I) and gold(III) complexes as therapeutic agents for cancer diseases

Metal complexes have demonstrated significant antitumor activities and platinum complexes are well established in the clinical application of cancer chemotherapy. However, the platinum-based treatment of different types of cancers is massively hampered by severe side effects and resistance development. Consequently, the development of novel metal-based drugs with different mechanism of action and pharmaceutical profile attracts modern medicinal chemists to design and synthesize novel metal-based agents. Among non-platinum anticancer drugs, gold complexes have gained considerable attention due to their significant antiproliferative potency and efficacy. In most situations, the gold complexes exhibit anticancer activities by targeting thioredoxin reductase (TrxR) or other thiol-rich proteins and enzymes and trigger cell death via reactive oxygen species (ROS). Interestingly, gold complexes were recently reported to elicit biochemical hallmarks of immunogenic cell death (ICD) as an ICD inducer. In this review, the recent progress of gold(I) and gold(III) complexes is comprehensively summarized, and their activities and mechanism of action are documented.

Preparation of NIR-Responsive Gold Nanocages as Efficient Carrier for Controlling Release of EGCG in Anticancer Application

Hepatocellular carcinoma (HCC) is a type of cancer that has a restricted therapy option. Epigallocatechin gallate (EGCG) is one of the main biologically active ingredients in tea. A large number of studies have shown that EGCG has preventive and therapeutic effects on various tumors. In addition, the development of near-infrared (NIR)-responsive nano-platforms has been attracting cancer treatment. In this work, we designed and synthesized a strategy of gold nanocages (AuNCs) as an efficient carrier for controlling release of EGCG for anti-tumor to achieve the synergistic functions of NIR-response and inhibited tumor cell proliferation. The diameter of AuNCs is about 50 nm and has a hollow porous (8 nm) structure. Thermal imaging-graphic studies proved that the AuNCs-EGCG obtained have photothermal response to laser irradiation under near-infrared light and still maintain light stability after multiple cycles of laser irradiation. The resulted AuNCs-EGCG reduced the proliferation rate of HepG2 cells to 50% at 48 h. Western blot analysis showed that NIR-responsive AuNCs-EGCG can promote the expression of HepG2 cell apoptosis-related proteins HSP70, Cytochrome C, Caspase-9, Caspase-3, and Bax, while the expression of Bcl-2 is inhibited. Cell confocal microscopy analysis proved that AuNCs-EGCG irradiated by NIR significantly upregulates Caspase-3 by nearly 2-fold and downregulates Bcl-2 by nearly 0.33-fold, which is beneficial to promote HepG2 cell apoptosis. This study provides useful information for the NIR-responsive AuNCs-EGCG as a new type of nanomedicine for HCC.