Research Progress of Metal Anticancer Drugs

Copper(II) Complexes of Pyrazolopyrimidine Derivatives as Anticancer Agents with Enhanced Chemodynamic Therapy through Bimodal Apoptosis and Ferroptosis

We reported 10 new copper(II) complexes 1-10 with pyrazolopyrimidine derivatives as ligands. Complexes 2 and 4 reacted with glutathione (GSH) in cells through Fenton-like reaction to generate highly toxic hydroxyl radical (·OH) for chemodynamic therapy (CDT), and reduced endogenous glutathione peroxidase 4 (GPX4) to induce ferroptosis. In addition, these complexes effectively caused mitochondrial dysfunction and induced apoptosis and autophagy in tumor cells. Furthermore, 2 and 4 effectively inhibited the bladder cancer cell growth in a xenograft model. This study presents new copper(II) complexes that can significantly induce bladder cancer cells death by enhanced CDT through bimodal apoptosis and ferroptosis, providing a promising approach for cancer therapy.

RIPK4 Downregulation Reduces ABCG2 Expression, Increasing BRAF-Mutated Melanoma Cell Susceptibility to Cisplatin- and Doxorubicin-Induced Apoptosis

Melanoma cells remain resistant to chemotherapy with cisplatin (CisPt) and doxorubicin (DOX). The abnormal expression of Receptor-Interacting Protein Kinase 4 (RIPK4) in certain melanomas contributes to tumour growth through the NFκB and Wnt/β-catenin signalling pathways, which are known to regulate chemoresistance and recurrence. Despite this, the role of RIPK4 in response to chemotherapeutics in melanoma has not been reported. In this study, we examined how the downregulation and overexpression of RIPK4 affect the sensitivity of BRAF-mutated melanoma cells (A375 and WM266.4) to CisPt and DOX along with determining the underlying mechanism. Using two RIPK4 silencing methods (siRNA and CRISPR/Cas9) and overexpression (dCas9-VPR), we assessed CisPt and DOX-induced apoptosis using caspase 3/7 activity, annexin V/7AAD staining, and FASC analysis. In addition, qRT-PCR and Western blotting were used to detect apoptosis-related genes and proteins such as cleaved PARP, p53, and cyclin D1. We demonstrated that the overexpression of RIPK4 inhibits, while its downregulation enhances, CisPt- or DOX-induced apoptosis in melanoma cells. The effects of downregulation are similar to those observed with pre-incubation with cyclosporin A, an ABCG2 inhibitor. Additionally, our findings provide preliminary evidence of crosstalk between RIPK4, BIRC3, and ABCG2. The results of these studies suggest the involvement of RIPK4 in the observed resistance to CisPt or DOX.

From Concept to Cure: The Road Ahead for Ruthenium-Based Anticancer Drugs

The evolution of chemotherapy, especially the dawn of metal-based drugs, represents a transformative era in cancer treatment. From the serendipitous discovery of mustard gas's cytotoxic effects to the sophisticated development of targeted therapies, chemotherapy has significantly refined. Central to this progression is the incorporation of metal-based compounds, such as platinum (Pt), ruthenium (Ru), and gold (Au), which offer unique mechanisms of action, distinguishing them from organic therapeutics. Among these, Ru complexes, exemplified by BOLD-100 and TLD1433, have shown exceptional promise due to their selective activity, lower propensity for resistance, and the ability to target spescific cellular pathways. This paper explores the journey of such Ru candidates, focusing on the mechanisms, efficacy, and clinical potential of these Ru-based drugs, which stand at the forefront of current research, aiming to provide more targeted, less toxic, and highly effective cancer treatments.

Significant enhancement of anticancer effect of iridium (III) complexes encapsulated in liposomes

In this study, the ligand EIPP (5-ethoxy-2-(1H-imidazo[4,5-f] [1,10] phenanthrolin-2-yl)phenol) and [Ir(ppy)2(EIPP)](PF6)] (5a, ppy = 2-phenylpyridine) and [Ir(piq)2(EIPP)](PF6)] (5b, piq = 1-phenylisoquinoline) were synthesized and they were entrapped into liposomes to produce 5alipo and 5blipo. 5a and 5b were characterized via HRMS, NMR, UV-vis and IR. The cytotoxicity of 5a, 5b, 5alipo and 5blipo on cancer and non-cancer cells was estimated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). MTT assay demonstrated that 5a and 5b did not show any significant cellular activity but their liposome-encapsulated 5alipo and 5blipo had significant toxic effects. The mechanism of 5alipo, 5blipo-inducing apoptosis was explored by studying cellular uptake, mitochondrial localization, mitochondrial membrane potential, cytochrome C, glutathione (GSH), malondialdehyde (MDA) and protein immunoblotting. The results demonstrated that 5alipo and 5blipo caused a release of cytochrome C, downregulated the expression of Bcl-2, upregulated the expression of BAX, activated caspase 3, and downregulated PARP expression. It was shown that 5alipo and 5blipo could inhibit cancer cell proliferation in G2/M phase by regulating p53 and p21 proteins. Additionally, 5alipo and 5blipo induced autophagy through an adjustment from LC3-I to LC3-II and caused ferroptosis. The in vivo antitumor activity of 5alipo was examined in detail.

Evaluation of Efficiency of Liposome-Entrapped Iridium(III) Complexes Inhibiting Tumor Growth In Vitro and In Vivo

In this paper, three new iridium(III) complexes: [Ir(piq)2(DFIPP)]PF6 (piq = deprotonated 1-phenylisoquinoline, DFIPP = 3,4-difluoro-2-(1H-imidazo[4,5-f][1,10]phenenthrolin-2-yl)phenol, 3a), [Ir(bzq)2(DFIPP)]PF6 (bzq = deprotonated benzo[h]quinoline, 3b), and [Ir(ppy)2(DFIPP)]PF6 (ppy = deprotonated 1-phenylpyridine, 3c), were synthesized and characterized. The complexes were found to be nontoxic to tumor cells via 3-(4,5-dimethylthiazole-2-yl)-diphenyltetrazolium bromide (MTT) assay. Surprisingly, its liposome-entrapped complexes 3alip, 3blip, and 3clip on B16 cells showed strong cytotoxicity (IC50 = 13.6 ± 2.8, 9.6 ± 1.1, and 18.9 ± 2.1 μM). Entry of 3alip, 3blip, and 3clip into B16 cells decreases mitochondrial membrane potential, regulates Bcl-2 family proteins, releases cytochrome c, triggers caspase family cascade reaction, and induces apoptosis. In addition, we also found that 3alip, 3blip, and 3clip triggered ferroptosis and autophagy. In vivo studies demonstrated that 3blip inhibited melanoma growth in C57 mice with a high inhibitory rate of 83.95%, and no organic damage was found in C57 mice.

PLGA-Loaded Nedaplatin (PLGA-NDP) Inhibits 7,12-Dimethylbenz[a]anthracene (DMBA) Induced Oral Carcinogenesis via Modulating Notch Signaling Pathway and Induces Apoptosis in Experimental Hamster Model

The present study is designed to evaluate the nanotherapeutic efficacy of prepared PLGA-loaded Nedaplatin (PLGA-NDP) against 7,12-dimethyl benz(a)anthracene (DMBA)-induced experimental oral carcinogenesis in hamster buccal pouch (HBP) model. The buccal pouch of golden Syrian hamsters was painted with 0.5% DMBA in liquid paraffin three times a week for 14 weeks, ultimately leading to the development of oral squamous cell carcinoma (OSCC). Oral administration of PLGA-NDP (preinitiation) and Cisplatin delivery (5 mg/kg b.wt) started 1 week before the carcinogen exposure and continued on alternative days. Post-administration of PLGA-NDP (5 mg/kg b.wt) started 2 days after carcinogen (DMBA) induction until the end of the experiment. After the 14th week, we observed that DMBA-painted hamsters exhibited tumor formation, morphological alterations, and well-differentiated OSSC in addition to the responsive molecular proteins during oral carcinogenesis. Furthermore, immunoblotting analysis demonstrated that PLGA-NDP inhibits Notch signaling, as evidenced by downregulation of Bcl-Xl, Bcl-2, p21, PGE2, HGF, and CXCL12 proteins, and upregulation of p53 and Bax. This apoptotic response is crucial for PLGA-NDP to induce apoptosis. In addition, RT-PCR results showed that PLGA-NDP nanoparticles play a downregulatory role in the therapeutic action of the notch signaling gene (Notch1, Notch 2, Hes1, Hey1, and Jagged1) at the mRNA transcription level in HBP carcinoma. Taken together, these data indicate that PLGA-NDP is a potent inhibitor of oral carcinogenesis and the expansion of cells that specifically target the Notch signaling pathway indicates that obstructing Notch signaling could potentially serve as a new and innovative therapeutic approach for oral squamous cell carcinoma (OSCC).

Nanomaterials: leading immunogenic cell death-based cancer therapies

The field of oncology has transformed in recent years, with treatments shifting from traditional surgical resection and radiation therapy to more diverse and customized approaches, one of which is immunotherapy. ICD (immunogenic cell death) belongs to a class of regulatory cell death modalities that reactivate the immune response by facilitating the interaction between apoptotic cells and immune cells and releasing specific signaling molecules, and DAMPs (damage-associated molecular patterns). The inducers of ICD can elevate the expression of specific proteins to optimize the TME (tumor microenvironment). The use of nanotechnology has shown its unique potential. Nanomaterials, due to their tunability, targeting, and biocompatibility, have become powerful tools for drug delivery, immunomodulators, etc., and have shown significant efficacy in clinical trials. In particular, these nanomaterials can effectively activate the ICD, trigger a potent anti-tumor immune response, and maintain long-term tumor suppression. Different types of nanomaterials, such as biological cell membrane-modified nanoparticles, self-assembled nanostructures, metallic nanoparticles, mesoporous materials, and hydrogels, play their respective roles in ICD induction due to their unique structures and mechanisms of action. Therefore, this review will explore the latest advances in the application of these common nanomaterials in tumor ICD induction and discuss how they can provide new strategies and tools for cancer therapy. By gaining a deeper understanding of the mechanism of action of these nanomaterials, researchers can develop more precise and effective therapeutic approaches to improve the prognosis and quality of life of cancer patients. Moreover, these strategies hold the promise to overcome resistance to conventional therapies, minimize side effects, and lead to more personalized treatment regimens, ultimately benefiting cancer treatment.

Analysis of hospitalization expenses and influencing factors for elderly cancer patients in a tertiary hospital in Dalian, China: a five‑year retrospective study

BACKGROUND

Because the proportion of elderly individuals and the incidence of cancer worldwide are continually increasing, medical costs for elderly inpatients with cancer are being significantly increasing, which puts tremendous financial pressure on their families and society. The current study described the actual direct medical costs of elderly inpatients with cancer and analyzed the influencing factors for the costs to provide advice on the prevention and control of the high medical costs of elderly patients with cancer.

METHOD

A retrospective descriptive analysis was performed on the hospitalization expense data of 11,399 elderly inpatients with cancer at a tier-3 hospital in Dalian between June 2016 and June 2020. The differences between different groups were analyzed using univariate analysis, and the influencing factors of hospitalization expenses were explored by multiple linear regression analysis.

RESULTS

The hospitalization cost of elderly cancer patients showed a decreasing trend from 2016 to 2020. Specifically, the top 3 hospitalization costs were material costs, drug costs and surgery costs, which accounted for greater than 10% of all cancers according to the classification: colorectal (23.96%), lung (21.74%), breast (12.34%) and stomach cancer (12.07%). Multiple linear regression analysis indicated that cancer type, surgery, year and length of stay (LOS) had a common impact on the four types of hospitalization costs (P < 0.05).

CONCLUSION

There were significant differences in the four types of hospitalization costs for elderly cancer patients according to the LOS, surgery, year and type of cancer. The study results suggest that the health administration department should enhance the supervision of hospital costs and elderly cancer patient treatment. Measures should be taken by relying on the hospital information system to strengthen the cost management of cancer diseases and departments, optimize the internal management system, shorten elderly cancer patients LOS, and reasonably control the costs of disease diagnosis, treatment and department operation to effectively reduce the economic burden of elderly cancer patients.

Biomaterials in Cancer Therapy: Investigating the Interaction between Kaempferol and Zinc Ions through Computational, Spectroscopic and Biological Analyses

A complex of the natural flavonoid kaempferol with zinc (Kam-Zn) was synthesized, and its physicochemical properties were investigated using spectroscopic methods such as Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Vis) spectroscopy and theoretical chemistry. Biological studies were conducted to evaluate the cytotoxic and antiproliferative effects of these complexes on MCF-7 breast cancer cells. Treatment with Kam 100 µM (84.86 ± 7.79%; 64.37 ± 8.24%) and Kam-Zn 100 µM (91.87 ± 3.80%; 87.04 ± 13.0%) showed no significant difference in proliferation between 16 h and 32 h, with the gap width remaining stable. Both Kam-Zn 100 μM and 200 μM demonstrated effective antiproliferative and cytotoxic activity, significantly decreasing cell viability and causing cell death and morphology changes. Antioxidant assays revealed that Kam (IC50 = 5.63 ± 0.06) exhibited higher antioxidant potential compared to Kam-Zn (IC50 = 6.80 ± 0.075), suggesting that zinc coordination impacts the flavonoid's radical scavenging activity by the coordination of metal ion to hydroxyl groups. Computational studies revealed significant modifications in the electronic structure and properties of Kam upon forming 1:1 complexes with Zn2+ ions. Spectroscopy analyses confirmed structural changes, highlighting shifts in absorption peaks and alterations in functional group vibrations indicative of metal-ligand interactions. FT-IR and UV-Vis spectra analysis suggested that Zn coordinates with the 3-OH and 4C=O groups of ligand. These findings suggest that the Kam-Zn complex exhibits interesting antiproliferative, cytotoxic and modified antioxidant effects on MCF-7 cells, providing valuable insights into their structural and anticancer properties.

(Pentamethylcyclopentadienyl)chloridoiridium(III) Complex Bearing Bidentate Ph2PCH2CH2SPh-κP,κS Ligand

The (pentamethylcyclopentadienyl)chloridoiridium(III) complex bearing a κP,κS-bonded Ph2PCH2CH2SPh ligand ([Ir(η5-C5Me5)Cl(Ph2P(CH2)2SPh-κP,κS)]PF6, (1)] was synthesized and characterized. Multinuclear (1H, 13C and 31P) NMR spectroscopy was employed for the determination of the structure. Moreover, SC-XRD confirmed the proposed structure belongs to the "piano stool" type. The Hirshfeld surface analysis outlined the most important intermolecular interactions in the structure. The crystallographic structure was optimized at the B3LYP-D3BJ/6-311++G(d,p)(H,C,P,S,Cl)/LanL2DZ(Ir) level of theory. The applicability of this level was verified through a comparison of experimental and theoretical bond lengths and angles, and 1H and 13C NMR chemical shifts. The Natural Bond Orbital theory was used to identify and quantify the intramolecular stabilization interactions, especially those between donor atoms and Ir(III) ions. Complex 1 was tested on antitumor activity against five human tumor cell lines: MCF-7 breast adenocarcinoma, SW480 colon adenocarcinoma, 518A2 melanoma, 8505C human thyroid carcinoma and A253 submandibular carcinoma. Complex 1 showed superior antitumor activity against cisplatin-resistant MCF-7, SW480 and 8505C cell lines. The mechanism of tumoricidal action on 8505C cells indicates the involvement of caspase-induced apoptosis, accompanied by a considerable reduction in ROS/RNS and proliferation potential of treated cells.

Modulating the Activity of the Human Organic Cation Transporter 2 Emerges as a Potential Strategy to Mitigate Unwanted Toxicities Associated with Cisplatin Chemotherapy

Cisplatin (CDDP) stands out as an effective chemotherapeutic agent; however, its application is linked to the development of significant adverse effects, notably nephro- and ototoxicity. The human organic cation transporter 2 (hOCT2), found in abundance in the basolateral membrane domain of renal proximal tubules and the Corti organ, plays a crucial role in the initiation of nephro- and ototoxicity associated with CDDP by facilitating its uptake in kidney and ear cells. Given its limited presence in cancer cells, hOCT2 emerges as a potential druggable target for mitigating unwanted toxicities associated with CDDP. Potential strategies for mitigating CDDP toxicities include competing with the uptake of CDDP by hOCT2 or inhibiting hOCT2 activity through rapid regulation mediated by specific signaling pathways. This study investigated the interaction between the already approved cationic drugs disopyramide, imipramine, and orphenadrine with hOCT2 that is stably expressed in human embryonic kidney cells. Regarding disopyramide, its influence on CDDP cellular transport by hOCT2 was further characterized through inductively coupled plasma isotope dilution mass spectrometry. Additionally, its potential protective effects against cellular toxicity induced by CDDP were assessed using a cytotoxicity test. Given that hOCT2 is typically expressed in the basolateral membrane of polarized cells, with specific regulatory mechanisms, this work studied the regulation of hOCT2 that is stably expressed in Madin-Darby Canine Kidney (MDCK) cells. These cells were cultured in a matrix to induce the formation of cysts, exposing hOCT2 in the basolateral plasma membrane domain, which was freely accessible to experimental solutions. The study specifically tested the regulation of ASP+ uptake by hOCT2 in MDCK cysts through the inhibition of casein kinase II (CKII), calmodulin, or p56lck tyrosine kinase. Furthermore, the impact of this manipulation on the cellular toxicity induced by CDDP was examined using a cytotoxicity test. All three drugs-disopyramide, imipramine, and orphenadrine-demonstrated inhibition of ASP+ uptake, with IC50 values in the micromolar (µM) range. Notably, disopyramide produced a significant reduction in the CDDP cellular toxicity and platinum cellular accumulation when co-incubated with CDDP. The activity of hOCT2 in MDCK cysts experienced a significant down-regulation under inhibition of CKII, calmodulin, or p56lck tyrosine kinase. Interestingly, only the inhibition of p56lck tyrosine kinase demonstrated the capability to protect the cells against CDDP toxicity. In conclusion, certain interventions targeting hOCT2 have demonstrated the ability to reduce CDDP cytotoxicity, at least in vitro. Further investigations in in vivo systems are warranted to ascertain their potential applicability as co-treatments for mitigating undesired toxicities associated with CDDP in patients.