Gold(III) porphyrin 1a inhibited nasopharyngeal carcinoma metastasis in vivo and inhibited cell migration and invasion in vitro

Monoacylglycerol lipase regulates macrophage polarization and cancer progression in uveal melanoma and pan-cancer

Background

Although lipid metabolism has been proven to play a key role in the development of cancer, its significance in uveal melanoma (UM) has not yet been elucidated in the available literature.

Methods

To identify the expression patterns of lipid metabolism in 80 UM patients from the TCGA database, 47 genes involved in lipid metabolism were analyzed. Consensus clustering revealed two distinct molecular groups. ESTIMATE, TIMER, and ssGSEA analyses were done to identify the differences between the two subgroups in tumor microenvironment (TME) and immune state. Using Cox regression and Lasso regression analysis, a risk model based on differentially expressed genes (DEGs) was developed. To validate the expression of monoacylglycerol lipase (MGLL) and immune infiltration in diverse malignancies, a pan-cancer cohort from the UCSC database was utilized. Next, a single-cell sequencing analysis on UM patients from the GEO data was used to characterize the lipid metabolism in TME and the role of MGLL in UM. Finally, in vitro investigations were utilized to study the involvement of MGLL in UM.

Results

Two molecular subgroups of UM patients have considerably varied survival rates. The majority of DEGs between the two subgroups were associated with immune-related pathways. Low immune scores, high tumor purity, a low number of immune infiltrating cells, and a comparatively low immunological state were associated with a more favorable prognosis. An examination of GO and KEGG data demonstrated that the risk model based on genes involved with lipid metabolism can accurately predict survival in patients with UM. It has been demonstrated that MGLL, a crucial gene in this paradigm, promotes the proliferation, invasion, and migration of UM cells. In addition, we discovered that MGLL is strongly expressed in macrophages, specifically M2 macrophages, which may play a function in the M2 polarization of macrophages and M2 macrophage activation in cancer cells.

Conclusion

This study demonstrates that the risk model based on lipid metabolism may be useful for predicting the prognosis of patients with UM. By promoting macrophage M2 polarization, MGLL contributes to the evolution of malignancy in UM, suggesting that it may be a therapeutic target for UM.

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.

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

Increasingly explored over the last decade, gold complexes have shown great promise in the field of cancer therapeutics. A major obstacle to their clinical progression has been their lack of in vivo stability, particularly for gold(III) complexes, which often undergo a facile reduction in the presence of biomolecules such as glutathione. Herein, we report a new class of promising anticancer gold(I)-gold(III) complexes with the general formula [XAuI(μ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuIIIX] [X = Cl (1), Br (2), NO3 (3)] which feature two gold atoms in different oxidation states (I and III) in a single molecule. Interestingly, gold(I)-gold(III) complexes (1-3) are stable against glutathione reduction under physiological-like conditions. In addition, complexes 1-3 exhibit significant cytotoxicity (276-fold greater than cisplatin) toward the tested cancer cells compared to the noncancerous cells. Moreover, the gold(I)-gold(III) complexes do not interact with DNA-like cisplatin but target cellular thioredoxin reductase, an enzyme linked to the development of cisplatin drug resistance. Complexes 1-3 also showed potential to inhibit cancer and endothelial cell migration, as well as tube formation during angiogenesis. In vivo studies in a murine HeLa xenograft model further showed the gold compounds may inhibit tumor growth on par clinically used cisplatin, supporting the significant potential this new compound class has for further development as cancer therapeutic.

Anticancer Gold(III) Compounds With Porphyrin or N-heterocyclic Carbene Ligands

The use of gold in medicine has a long history. Recent clinical applications include anti-inflammatory agents for the treatment of rheumatoid arthritis (chrysotherapy), and is currently being developed as potential anticancer chemotherapeutics. Gold(III), being isoelectronic to platinum(II) as in cisplatin, is of great interest but it is inherently unstable and redox-reactive under physiological conditions. Coordination ligands containing C and/or N donor atom(s) such as porphyrin, pincer-type cyclometalated and/or N-heterocyclic carbene (NHC) can be employed to stabilize gold(III) ion for the preparation of anticancer active compounds. In this review, we described our recent work on the anticancer properties of gold(III) compounds and the identification of molecular targets involved in the mechanisms of action. We also summarized the chemical formulation strategies that have been adopted for the delivery of cytotoxic gold compounds, and for ameliorating the in vivo toxicity.

Multifunctional Microparticles Incorporating Gold Compound Inhibit Human Lung Cancer Xenograft

PURPOSE

Gold porphyrin (AuP) is a complex that has been shown to be potent against various tumors. A biocompatible interpenetrating network (IPN) system comprised of polyethyleneglycol diacrylate (PEGdA) and chemically-modified gelatin has been shown to be an effective implantable drug depot to deliver AuP locally. Here we designed IPN microparticles complexed with AuP to facilitate intravenous administration and to diminish systemic toxicity.

METHODS

We have synthesized and optimized an IPN microparticle formulation complexed with AuP. Tumor cell cytotoxicity, antitumor activity, and survival rate in lung cancer bearing nude mice were analyzed.

RESULTS

IPN microparticles maintained AuP bioactivity against lung cancer cells (NCI-H460). In vivo study showed no observable systemic toxicity in nude mice bearing NCI-H460 xenografts after intravenous injection of 6 mg/kg AuP formulated with IPN microparticles. An anti-tumor activity level comparable to free AuP was maintained. Mice treated with 6 mg/kg AuP in IPN microparticles showed 100% survival rate while the survival rate of mice treated with free AuP was much less. Furthermore, microparticle-formulated AuP significantly reduced the intratumoral microvasculature when compared with the control.

CONCLUSION

AuP in IPN microparticles can reduce the systemic toxicity of AuP without compromising its antitumor activity. This work highlighted the potential application of AuP in IPN microparticles for anticancer chemotherapy.

Synthesis, characterization and anticancer activity in vitro evaluation of novel dicyanoaurate (I)-based complexes

Molecular structures containing gold, such as auranofin, have been extensively studied in the diagnosis and treatment of many diseases, including cancer treatment. The pharmacological properties of the newly synthesized unique gold-ligand structures have been reported for different cancer cell lines. However, findings on bishydeten-metal salt complexes with gold are rare. In this work, the synthesis of five novel cyanide-bridged coordination compounds having the closed formulae [Ni(bishydeten)][Au(CN)₂]₂ (1), [Cu(bishydeten)][Au(CN)₂]₂ (2), [Zn(bishydeten)₂Au₃(CN)₄][Au₂(CN)₃] (3), [Cd(bishydeten)_0,5]₂[Au(CN)₂]₄.2H₂O (4), and [Cd(bishydeten)₂][Au(CN)₂]₂ (5) (where bisyhdeten = N,N-bis(2-hydroxyethyl)ethylene diamine), and their characterization by elemental, infrared, ESI-MS, X-ray (for 2) and thermic measurement methods were performed. Complexes 1 and 3 are thermally more stable than the other three complexes. For these, pharmacological adequacies were also tested. The nucleic acid and protein binding affinities of the Au (I) compounds were also estimated by spectroscopic and electrophoretic techniques. Au (I) complexes were identified as strong chemotherapeutic with mild cytotoxicity, and they demonstrated a dose-dependent inhibition on the growth of cancer cells with IC50 at 0.11 to 0.47 μM. Investigation of mechanisms of action on cells revealed that Au (I) compounds managed to inhibit cell migration and led to a decrease in cytoskeletal proteins such as CK7 and CK20. However, Au (I) compounds failed to inhibit DNA topoisomerase I. Overall, and we suggest that potent antiproliferative activity, mild cytotoxicity, good solubility, and micromolar dosage of Au (I) compounds containing bisyhdeten-metal derivatives render them the potential focus of further studies as chemotherapeutic agents.

Binding of Gold(III) Porphyrin by the Pro-metastatic Regulatory Protein Human Galectin-3

Gold(III) porphyrin presents an attractive alternative to the use of, for example, cisplatin in chemotherapy. However, approaches that allow to selectively target cancer cells are highly sought. Many plant and mammalian lectins have been shown to bind oligosaccharide sequences of the aberrant glycosylation pattern found on cancerous tumors. For example human galectin-3, of the galectin family specific for β-galactoside, is overexpressed in the extracellular matrix of tumorigenous and metastatic tissues. We searched for non-carbohydrate ligands for galectin-3 that can guide a cytotoxic drug to the cancer cells by maintaining its affinity for tumor associated carbohydrate antigens. Previous findings showed that zinc tetrasulfonatophenylporphyrin can bind galectin-3 with sub-micromolar affinity without disturbing lactose binding. Gold(III) porphyrin is not only cytotoxic to cancer cells, it knows also a potential application as photosensitiser in photodynamic therapy. We investigated the binding of gold(III) porphyrin to galectin-3 using different biophysical interaction techniques and demonstrated a low micromolar affinity of human galectin-3 for the cytotoxic compound. Co-crystallization attempts in order to understand the binding mode of gold porphyrin to galectin-3 failed, but molecular docking emphasized a highly populated secondary binding site that does not hinder lactose or Thomsen Friendenreich disaccharide binding. This suggests that gold(III) porphyrin might significantly enhance its concentration and delivery to cancer cells by binding to human galectin-3 that keeps its orientation towards tumor associated carbohydrate antigens.

Gold-Based Medicine: A Paradigm Shift in Anti-Cancer Therapy?

A new era of metal-based drugs started in the 1960s, heralded by the discovery of potent platinum-based complexes, commencing with cisplatin [(H₃N)₂PtCl₂], which are effective anti-cancer chemotherapeutic drugs. While clinical applications of gold-based drugs largely relate to the treatment of rheumatoid arthritis, attention has turned to the investigation of the efficacy of gold(I) and gold(III) compounds for anti-cancer applications. This review article provides an account of the latest research conducted during the last decade or so on the development of gold compounds and their potential activities against several cancers as well as a summary of possible mechanisms of action/biological targets. The promising activities and increasing knowledge of gold-based drug metabolism ensures that continued efforts will be made to develop gold-based anti-cancer agents.

Water-soluble Manganese and Iron Mesotetrakis(carboxyl)porphyrin: DNA Binding, Oxidative Cleavage, and Cytotoxic Activities

Two new water-soluble metal carboxyl porphyrins, manganese (III) meso-tetrakis (carboxyl) porphyrin and iron (III) meso-tetrakis (carboxyl) porphyrin, were synthesized and characterized. Their interactions with ct-DNA were investigated by UV-Vis titration, fluorescence spectra, viscosity measurement and CD spectra. The results showed they can strongly bind to ct-DNA via outside binding mode. Electrophoresis experiments revealed that both complexes can cleave pBR322 DNA efficiently in the presence of hydrogen peroxide, albeit 2-Mn exhibited a little higher efficiency. The inhibitor tests suggest the oxidative DNA cleavage by these two complexes may involve hydroxyl radical active intermediates. Notably, 2-Mn exhibited considerable photocytotoxicity against Hep G2 cell via triggering a significant generation of ROS and causing disruption of MMP after irradiation.

Modeling nasopharyngeal carcinoma in three dimensions

Nasopharyngeal carcinoma (NPC) is a type of cancer endemic in Asia, including Malaysia, Southern China, Hong Kong and Taiwan. Treatment resistance, particularly in recurring cases, remains a challenge. Thus, studies to develop novel therapeutic agents are important. Potential therapeutic compounds may be effectively examined using two-dimensional (2D) cell culture models, three-dimensional (3D) spheroid models or in vivo animal models. The majority of drug assessments for cancers, including for NPC, are currently performed with 2D cell culture models. This model offers economical and high-throughput screening advantages. However, 2D cell culture models cannot recapitulate the architecture and the microenvironment of a tumor. In vivo models may recapitulate certain architectural and microenvironmental conditions of a tumor, however, these are not feasible for the screening of large numbers of compounds. By contrast, 3D spheroid models may be able to recapitulate a physiological microenvironment not observed in 2D cell culture models, in addition to avoiding the impediments of in vivo animal models. Thus, the 3D spheroid model offers a more representative model for the study of NPC growth, invasion and drug response, which may be cost-effective without forgoing quality.

Development of individualized anti-metastasis strategies by engineering nanomedicines

Metastasis is deadly and also tough to treat as it is much more complicated than the primary tumour. Anti-metastasis approaches available so far are far from being optimal. A variety of nanomedicine formulae provide a plethora of opportunities for developing new strategies and means for tackling metastasis. It should be noted that individualized anti-metastatic nanomedicines are different from common anti-cancer nanomedicines as they specifically target different populations of malignant cells. This review briefly introduces the features of the metastatic cascade, and proposes a series of nanomedicine-based anti-metastasis strategies aiming to block each metastatic step. Moreover, we also concisely introduce the advantages of several promising nanoparticle platforms and their potential for constructing state-of-the-art individualized anti-metastatic nanomedicines.

Linking the future of anticancer metal-complexes to the therapy of tumour metastases

Cancer chemotherapy is almost always applied to patients with one or more diagnosed metastases and is expected to impact these lesions, thus providing significant benefits to the patient.

Chemical biology of anticancer gold(iii) and gold(i) complexes

Anticancer gold complexes, including their mechanisms of action and the approaches adopted to improve the anticancer efficiency are described.

Novel amphiphilic cationic porphyrin and its Ag(II) complex as potential anticancer agents

In the present study we have synthesized a novel amphiphilic porphyrin and its Ag(II) complex through modification of water-soluble porphyrinic structure in order to increase its lipophilicity and in turn pharmacological potency. New cationic non-symmetrical meso-substituted porphyrins were characterized by UV-visible, electrospray ionization mass spectrometry (ESI-MS), (1)H NMR techniques, lipophilicity (thin-layer chromatographic retention factor, Rf), and elemental analysis. The key toxicological profile (i.e. cytotoxicity and cell line- (cancer type-) specificity; genotoxicity; cell cycle effects) of amphiphilic Ag porphyrin was studied in human normal and cancer cell lines of various tissue origins and compared with its water-soluble analog. Structural modification of the molecule from water-soluble to amphiphilic resulted in a certain increase in the cytotoxicity and a decrease in cell line-specificity. Importantly, Ag(II) porphyrin showed less toxicity to normal cells and greater toxicity to their cancerous counterparts as compared to cisplatin. The amphiphilic complex was also not genotoxic and demonstrated a slight cytostatic effect via the cell cycle delay due to the prolongation of S-phase. As expected, the performed structural modification affected also the photocytotoxic activity of metal-free amphiphilic porphyrin. The ligand tested on cancer cell line revealed a dramatic (more than 70-fold) amplification of its phototoxic activity as compared to its water-soluble tetracationic metal-free analog. The compound combines low dark cytotoxicity with 5 fold stronger phototoxicity relative to Chlorin e6 and could be considered as a potential photosensitizer for further development in photodynamic therapy.

An orthotopic model of metastatic nasopharyngeal carcinoma and its application in elucidating a therapeutic target that inhibits metastasis

To define and therapeutically target mechanisms that mediate nasopharyngeal carcinoma (NPC) metastasis, we have developed a unique orthotopic xenograft mouse model that accurately recapitulates the invasive and metastatic behavior of human disease. Based on clinical and laboratory evidence that the PI3K/Akt/mTOR axis is involved in aggressive NPC tumor behavior, we chose it as a therapeutic target to test the utility of our orthotopic system for evaluating the effectiveness of a targeted treatment for metastatic NPC. Demonstrated herein, we have shown that both the development and growth of metastatic lesions are markedly reduced by the mTOR inhibitor sirolimus. Thus, this orthotopic model provides a platform to study potential therapeutics for advanced NPC and demonstrates that targeting the PI3K/Akt/mTOR pathway is a promising intervention against disseminated disease.

Synthesis and cancer cell cytotoxicity of water-soluble gold(III) substituted tetraarylporphyrin

The synthesis of novel substituted gold(III) tetraarylporphyrins with aqueous solubility has been carried out. The analogs ClAuTPP(CH(3)Py(+)·I(-)), ClAuTCPPNa, ClAuTPPCO(2)Na, ClAuTSPPNa and ClAuTPPNH(2)·HCl were evaluated for their in vitro cytotoxic activity against sarcoma 180 mouse tumor and SGC-7901 human gastric cancer cell line panel. Compound ClAuTCPPNa exhibited significant growth inhibitory properties against sarcoma 180 mouse tumor and SGC-7901 human gastric cancer cell examined, and afforded IC(50) values <25 μM for 66.63% of the cell lines in the panel. Compound ClAuTPPNH(2)·HCl was an effective inhibitor of sarcoma 180 mouse tumor and SGC-7901 human gastric cancer cell growth, but generally less effective as a cytotoxic agent. Thus, the substituted gold(III) porphyrin ClAuTCPP-Na(+) and ClAuTPPNH(2)·HCl with aqueous solubility were regarded as useful lead compounds for further structural optimization.

Preserving charge and oxidation state of Au(III) ions in an agent-functionalized nanocrystal model system

Supporting functional molecules on crystal facets is an established technique in nanotechnology. To preserve the original activity of ionic metallorganic agents on a supporting template, conservation of the charge and oxidation state of the active center is indispensable. We present a model system of a metallorganic agent that, indeed, fulfills this design criterion on a technologically relevant metal support with potential impact on Au(III)-porphyrin-functionalized nanoparticles for an improved anticancer-drug delivery. Employing scanning tunneling microscopy and -spectroscopy in combination with photoemission spectroscopy, we clarify at the single-molecule level the underlying mechanisms of this exceptional adsorption mode. It is based on the balance between a high-energy oxidation state and an electrostatic screening-response of the surface (image charge). Modeling with first principles methods reveals submolecular details of the metal-ligand bonding interaction and completes the study by providing an illustrative electrostatic model relevant for ionic metalorganic agent molecules, in general.

Metal-based antitumour drugs in the post-genomic era: what comes next?

In our Dalton Transactions Perspective article entitled, 'Metal-based antitumour drugs in the post genomic era', (Dalton Trans., 2006, 1929-1933) we discussed metal-based drugs in light of past decades of research. We concluded that the post-genomic era would dictate a change in the direction of the field with knowledge of the genome increasingly allowing protein targets to be identified and not simply assuming that DNA is the only relevant target of metal-based drugs. Since our article was published new insights into the mode of action of metal-based drugs have emerged making some older findings increasingly relevant to current drug design. In this article we discuss these developments in terms of what we believe should be the future direction for the field.

Therapeutic applications of gold complexes: lipophilic gold(III) cations and gold(I) complexes for anti-cancer treatment

Gold and its complexes have long been known to display unique biological and medicinal properties. Extensive cell-based (in vitro) and animal (in vivo) studies have revealed the potent anti-cancer activities of diverse classes of gold(I) and gold(III) complexes. Most of the reported anti-cancer active gold complexes are highly cytotoxic and unstable under physiological conditions, which hamper their development to be launched clinically. Several clinical reports showed that lipophilic organic cations are promising anti-cancer drug candidates targeting to mitochondria. Through metal-ligand coordination, gold(I) and gold(III) ions can form stable lipophilic cations containing organic ligands having tunable lipophilicity and diverse functionalities. The present highlight summarizes the recent development of lipophilic gold(III) cations and gold(I) complexes with promising anti-cancer activities.

Gold(III) porphyrin 1a prolongs the survival of melanoma-bearing mice and inhibits angiogenesis

BACKGROUND

Gold(III) meso-tetraphenylporphyrin (gold-1a) has previously been shown to prolong the survival of hepatocellular carcinoma (HCC)-bearing rats and nasopharyngeal carcinoma (NPC) metastasis-bearing mice. It has also been proved to inhibit the tumor growth of mice bearing NPC, neuroblastoma and colon carcinoma. Mechanistically, gold-1a induces apoptosis, inhibits cell migration and invasion. In this study the efficacies of gold-1a in inhibiting melanoma and angiogenesis were investigated.

MATERIAL AND METHODS

A mouse melanoma model was used to investigate the efficacy of gold-1a in inhibiting angiogenesis, tumor growth and prolonging the survival of the tumor-bearing animals. The model was established by inoculation of 2 × 10(5) B16-F1 mouse melanoma cells into the right back flanks of the mice by subcutaneous inoculation. When the tumors grew to 0.2-0.4 cm in diameters, the mice were treated with gold-1a, solvent control or dacarbazine (DTIC) for comparison. Tumor sizes and animal survivals were monitored throughout the experiment. Tumor tissues were collected and immunohistochemically stained with CD31 antibodies for evaluation of intra-tumoral microvessel density (iMVD).

RESULTS AND CONCLUSION

Gold-1a significantly prolonged the survivals, reduced angiogenesis and tumor growth rates of melanoma-bearing mice. The compound induced necrosis and apoptosis in the mouse melanoma tissues. Gold-1a also downregulated the expression of genes playing roles in angiogenesis. Gold-1a may potentially be used to treat melanoma in patients.