Stress granule-mediated sequestration of EGR1 mRNAs correlates with lomustine-induced cell death prevention.

Some chemotherapy drugs modulate the formation of stress granules (SGs), which are RNA-containing cytoplasmic foci contributing to stress response pathways. How SGs mechanistically contribute to pro-survival or pro-apoptotic functions must be better defined. The chemotherapy drug lomustine promotes SG formation by activating the stress-sensing eIF2α kinase HRI (encoded by the EIF2AK1 gene). Here, we applied a DNA microarray-based transcriptome analysis to determine the genes modulated by lomustine-induced stress and suggest roles for SGs in this process. We found that the expression of the pro-apoptotic EGR1 gene was specifically regulated in cells upon lomustine treatment. The appearance of EGR1-encoding mRNA in SGs correlated with a decrease in EGR1 mRNA translation. Specifically, EGR1 mRNA was sequestered to SGs upon lomustine treatment, probably preventing its ribosome translation and consequently limiting the degree of apoptosis. Our data support the model where SGs can selectively sequester specific mRNAs in a stress-specific manner, modulate their availability for translation, and thus determine the fate of a stressed cell.

Failure to progress: breast and prostate cancer cell lines in developing targeted therapies.

Developing anticancer drugs from preclinical to clinical takes approximately a decade in a cutting-edge biomedical lab and still 97% of most fail at clinical trials. Cell line usage is critical in expediting the advancement of anticancer therapies. Yet developing appropriate cell lines has been challenging and overcoming these obstacles whilst implementing a systematic approach of utilizing 3D models that recapitulate the tumour microenvironment is prudent. Using a robust and continuous supply of cell lines representing all ethnic groups from all locales is necessary to capture the evolving tumour landscape in culture. Next, the conversion of these models to systems on a chip that can by way of high throughput cytotoxic assays identify drug leads for clinical trials should fast-track drug development while markedly improving success rates. In this review, we describe the challenges that have hindered the progression of cell line models over seven decades and methods to overcome this. We outline the gaps in breast and prostate cancer cell line pathology and racial representation alongside their involvement in relevant drug development.

USP7 limits CDK1 activity throughout the cell cycle.

Chemical inhibitors of the deubiquitinase USP7 are currently being developed as anticancer agents based on their capacity to stabilize P53. Regardless of this activity, USP7 inhibitors also generate DNA damage in a p53-independent manner. However, the mechanism of this genotoxicity and its contribution to the anticancer effects of USP7 inhibitors are still under debate. Here we show that, surprisingly, even if USP7 inhibitors stop DNA replication, they also induce a widespread activation of CDK1 throughout the cell cycle, which leads to DNA damage and is toxic for mammalian cells. In addition, USP7 interacts with the phosphatase PP2A and supports its active localization in the cytoplasm. Accordingly, inhibition of USP7 or PP2A triggers very similar changes of the phosphoproteome, including a widespread increase in the phosphorylation of CDK1 targets. Importantly, the toxicity of USP7 inhibitors is alleviated by lowering CDK1 activity or by chemical activation of PP2A. Our work reveals that USP7 limits CDK1 activity at all cell cycle stages, providing a novel mechanism that explains the toxicity of USP7 inhibitors through untimely activation of CDK1.

A granularity-level information fusion strategy on hypergraph transformer for predicting synergistic effects of anticancer drugs.

Combination therapy has exhibited substantial potential compared to monotherapy. However, due to the explosive growth in the number of cancer drugs, the screening of synergistic drug combinations has become both expensive and time-consuming. Synergistic drug combinations refer to the concurrent use of two or more drugs to enhance treatment efficacy. Currently, numerous computational methods have been developed to predict the synergistic effects of anticancer drugs. However, there has been insufficient exploration of how to mine drug and cell line data at different granularity levels for predicting synergistic anticancer drug combinations. Therefore, this study proposes a granularity-level information fusion strategy based on the hypergraph transformer, named HypertranSynergy, to predict synergistic effects of anticancer drugs. HypertranSynergy introduces synergistic connections between cancer cell lines and drug combinations using hypergraph. Then, the Coarse-grained Information Extraction (CIE) module merges the hypergraph with a transformer for node embeddings. In the CIE module, Contranorm is a normalization layer that mitigates over-smoothing, while Gaussian noise addresses local information gaps. Additionally, the Fine-grained Information Extraction (FIE) module assesses fine-grained information's impact on predictions by employing similarity-aware matrices from drug/cell line features. Both CIE and FIE modules are integrated into HypertranSynergy. In addition, HypertranSynergy achieved the AUC of 0.93${\pm }$0.01 and the AUPR of 0.69${\pm }$0.02 in 5-fold cross-validation of classification task, and the RMSE of 13.77${\pm }$0.07 and the PCC of 0.81${\pm }$0.02 in 5-fold cross-validation of regression task. These results are better than most of the state-of-the-art models.

Multiplexed cellular profiling identifies an organoselenium compound as an inhibitor of CRM1-mediated nuclear export.

Chromosomal region maintenance 1 (CRM1 also known as Xpo1 and exportin-1) is the receptor for the nuclear export controlling the intracellular localization and function of many cellular and viral proteins that play a crucial role in viral infections and cancer. The inhibition of CRM1 has emerged as a promising therapeutic approach to interfere with the lifecycle of many viruses, for the treatment of cancer, and to overcome therapy resistance. Recently, selinexor has been approved as the first CRM1 inhibitor for the treatment of multiple myeloma, providing proof of concept for this therapeutic option with a new mode of action. However, selinexor is associated with dose-limiting toxicity and hence, the discovery of alternative small molecule leads that could be developed as less toxic anticancer and antiviral therapeutics will have a significant impact in the clinic. Here, we report a CRM1 inhibitor discovery platform. The development of this platform includes reporter cell lines that monitor CRM1 activity by using red fluorescent protein or green fluorescent protein-labeled HIV-1 Rev protein with a strong heterologous nuclear export signal. Simultaneously, the intracellular localization of other proteins, to be interrogated for their capacity to undergo CRM1-mediated export, can be followed by co-culturing stable cell lines expressing fluorescent fusion proteins. We used this platform to interrogate the mode of nuclear export of several proteins, including PDK1, p110α, STAT5A, FOXO1, 3, 4 and TRIB2, and to screen a compound collection. We show that while p110α partially relies on CRM1-dependent nuclear export, TRIB2 is exported from the nucleus in a CRM1-independent manner. Compound screening revealed the striking activity of an organoselenium compound on the CRM1 nuclear export receptor.

Characteristics of clinical trials of new oncology drugs approved in China.

BACKGROUND: Since reforms were introduced to incentivize drug innovation in 2015, the Chinese pharmaceutical market has experienced unprecedented prosperity, with more new drugs than ever before, especially anticancer treatments. In 2021, Chinese regulatory agencies issued the new guideline for clinical research and development of antitumor drugs, triggering a series of responses on the drug market. Limited research has outlined the nature of the original new drugs in China to understand the dynamic response of the market. METHODS: The objective of this article was to map the clinical development of approved new oncology drugs in China from 2015 to 2021 and differed from previous studies by focusing on original new drugs, using the United States as a benchmark, and elaborating the endogenous features of clinical trials. RESULTS: Clinical trials conducted in China have risen to a level similar to that of the United States in many aspects of trial design, but there is still distance between the implementation and operational details of clinical trials. In the meantime, China has made significant breakthroughs in drug approval. Greater than 60% of novel anticancer drugs in China received accelerated approved for their first listing. Approximately 90% of the pivotal clinical trials supporting initial drug approval used surrogate measures as end points, and one half were nonrandomized or did not have a control group. However, duplicate development without evidence of a clinical advantage compared with current therapies was widely observed. CONCLUSIONS: By presenting a multidimensional landscape of clinical trials and approvals in the real world, this review allows interested researchers, developers, and even regulators to understand what has been done and what should be done next in anticancer drug development in China.

Opioid metabolism and drug-drug interaction in cancer.

Concomitant use of multiple drugs in most patients with cancer may result in drug-drug interactions (DDIs), potentially causing serious adverse effects. These patients often experience unrelieved cancer-related pain (CRP) during and after cancer treatment, which can lead to a reduced quality of life. Opioids can be used as part of a multimodal pain management strategy when non-opioid analgesics are not providing adequate pain relief, not tolerated, or are contraindicated. However, due to their narrow therapeutic window, opioids are more susceptible to adverse events when a DDI occurs. Clinically relevant DDIs with opioids are usually pharmacokinetic, mainly occurring via metabolism by cytochrome P450 (CYP). This article aims to provide an overview of potential DDIs with opioids often used in the treatment of moderate-to-severe CRP and commonly used anticancer drugs such as chemotherapeutics, tyrosine kinase inhibitors (TKIs), or biologics. A DDI-checker tool was used to contextualize the tool-informed DDI assessment outcomes with clinical implications and practice. The findings were compared to observations from a literature search conducted in Embase and PubMed to identify clinical evidence for these potential DDIs. The limited results mainly included case studies and retrospective reviews. Some potential DDIs on the DDI-checker were aligned with literature findings, while others were contradictory. In conclusion, while DDI-checkers are useful tools in identifying potential DDIs, it is necessary to incorporate literature verification and comprehensive clinical assessment of the patient before implementing tool-informed decisions in clinical practice.

An AIEgen and Iodine Double-Ornamented Platinum(II) Complex for Bimodal Imaging-Guided Chemo-Photodynamic Combination Therapy.

Real-time biodistribution monitoring and enhancing the therapeutic efficacy of platinum(II)-based anticancer drugs are urgently required to elevate their clinical performance. Herein, a tetraphenylethene derivative (TP) with aggregation-induced emission (AIE) properties and an iodine atom are selected as ligands to endow platinum (II) complex TP-Pt-I with real-time in vivo self-tracking ability by fluorescence (FL) and computerized tomography (CT) imaging, and improved anticancer efficacy by the combination of chemotherapy and photodynamic therapy. Especially, benefiting from the formation of a donor-acceptor-donor structure between the AIE photosensitizer TP and Pt-I moiety, the heavy atom effects of Pt and I, and the presence of I, TP-Pt-I displayed red-shifted absorption and emission wavelengths, enhanced ROS generation efficiency, and improved CT imaging capacity compared with the pristine TP and the control agent TP-Pt-Cl. As a result, the enhanced intratumoral accumulation of TP-Pt-I loaded nanoparticles is readily revealed by dual-modal FL and CT imaging with high contrast. Meanwhile, the TP-Pt-I nanoparticles show significantly improved tumor growth-inhibiting effects on an MCF-7 xenograft murine model by combining the chemotherapeutic effects of platinum(II) and the photodynamic effects of TP. This self-tracking therapeutic complex thus provides a new strategy for improving the therapeutic outcomes of platinum(II)-based anticancer drugs.

The leaf idioblastome of the medicinal plant Catharanthus roseus is associated with stress resistance and alkaloid metabolism.

Catharanthus roseus leaves produce a range of monoterpenoid indole alkaloids (MIAs) that include low levels of the anticancer drugs vinblastine and vincristine. The MIA pathway displays a complex architecture spanning different subcellular and cell type localizations, and is under complex regulation. As a result, the development of strategies to increase the levels of the anticancer MIAs has remained elusive. The pathway involves mesophyll specialized idioblasts where the late unsolved biosynthetic steps are thought to occur. Here, protoplasts of C. roseus leaf idioblasts were isolated by fluorescence-activated cell sorting, and their differential alkaloid and transcriptomic profiles were characterized. This involved the assembly of an improved C. roseus transcriptome from short- and long-read data, IDIO+. It was observed that C. roseus mesophyll idioblasts possess a distinctive transcriptomic profile associated with protection against biotic and abiotic stresses, and indicative that this cell type is a carbon sink, in contrast to surrounding mesophyll cells. Moreover, it is shown that idioblasts are a hotspot of alkaloid accumulation, suggesting that their transcriptome may hold the key to the in-depth understanding of the MIA pathway and the success of strategies leading to higher levels of the anticancer drugs.

Phototoxicity of cyclometallated Ir(III) complexes bearing a thio-bis-benzimidazole ligand, and its monodentate analogue, as potential PDT photosensitisers in cancer cell killing.

Two novel cyclometallated iridium(III) complexes have been prepared with one bidentate or two monodentate imidazole-based ligands, 1 and 2, respectively. The complexes showed intense emission with long lifetimes of the excited state. Femtosecond transient absorption experiments established the nature of the lowest excited state as 3IL state. Singlet oxygen generation with good yields (40% for 1 and 82% for 2) was established by detecting 1O2 directly, through its emission at 1270 nm. Photostability studies were also performed to assess the viability of the complexes as photosensitizers (PS) for photodynamic therapy (PDT). Complex 1 was selected as a good candidate to investigate light-activated killing of cells, whilst complex 2 was found to be toxic in the dark and unstable under light. Complex 1 demonstrated high phototoxicity indexes (PI) in the visible region, PI > 250 after irradiation at 405 nm and PI > 150 at 455 nm, in EJ bladder cancer cells.

Design, synthesis, and biological evaluation of novel halogenated chlorido[N,N'-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes as anticancer agents.

Iron(III) complexes based on N,N´-bis(salicylidene)ethylenediamine (salene) scaffolds have demonstrated promising anticancer features like induction of ferroptosis, an iron dependent cell death. Since poor cellular uptake limits their therapeutical potential, this study aimed to enhance the lipophilic character of chlorido[N,N'-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes by introducing lipophilicity improving ligands such as fluorine (X1), chlorine (X2) and bromine (X3) in 5-position in the salicylidene moieties. After detailed characterization the binding to nucleophiles, logP values and cellular uptake were determined. The complexes were further evaluated regarding their biological activity on MDA-MB 231 mammary carcinoma, the non-tumorous SV-80 fibroblast, HS-5 stroma and MCF-10A mammary gland cell lines. Stability of the complexes in aqueous and biological environments was proven by the lack of interactions with amino acids and glutathione. Cellular uptake was positively correlated with the logP values, indicating that higher lipophilicity enhanced cellular uptake. The complexes induced strong antiproliferative and antimetabolic effects on MDA-MB 231 cells, but were inactive on all non-malignant cells tested. Generation of mitochondrial reactive oxygen species, increase of lipid peroxidation and induction of both ferroptosis and necroptosis were identified as mechanisms of action. In conclusion, halogenation of chlorido[N,N'-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes raises their lipophilic character resulting in improved cellular uptake.

Optical and supramolecular properties of cyclometalated palladium nanostructures with tumor targeting properties in living mice: a quantum mechanics interpretation.

The recent discovery that metallophilic interactions between cyclometalated palladium supramolecular nanostructures - with efficient tumour accumulation rate in a skin melanoma model - maintain excellent photodynamic properties even in a hypoxic microenvironment has inspired the present study focused on the theoretical predictions of optical properties of the bis-cyclometalated palladium compound in different contexts. More specifically, structural and UV/Vis absorption properties of both monomeric and dimeric forms of this anticancer drug are well reproduced with a Time-Dependent Density Functional Theoretical (TD-DFT) approach based on Exchange-Correlation (XC) hybrid functionals in conjunction with conductor-like and polarization solvation effects. A further novelty is represented by a fine investigation of the supramolecular interactions between the different subunits of the drug via dispersion force correction and Quantum Theory of Atoms in Molecules (QTAIM). This contribution while supporting the photoexcitation properties derived in laboratory following the self-assembly of monomeric units when passing from dimethyl sulfoxide (DMSO) to a H2O/DMSO mixture at 298K, shed some light on the nature of the chemical interactions modulating the formation of nano-size aggregates.

Docetaxel Inhibits Epithelial-Mesenchymal Transition in Human Mammary Cells.

Epithelial-mesenchymal transition (EMT) is a reversible and dynamic biological process in which epithelial cells acquire mesenchymal characteristics including enhanced stemness and migratory ability. EMT can facilitate cancer metastasis and is a known driver of cellular resistance to common chemotherapeutic drugs, such as docetaxel. Current chemotherapeutic practices such as docetaxel treatment can promote EMT and increase the chance of tumor recurrence and resistance, calling for new approaches in cancer treatment. Here we show that prolonged docetaxel treatment at a sub-IC50 concentration inhibits EMT in immortalized human mammary epithelial (HMLE) cells. Using immunofluorescence, flow cytometry, and bulk transcriptomic sequencing to assess EMT progression, we analyzed a range of cellular markers of EMT in docetaxel-treated cells and observed an upregulation of epithelial markers and downregulation of mesenchymal markers in the presence of docetaxel. This finding suggests that docetaxel may have clinical applications not only as a cytotoxic drug but also as an inhibitor of EMT-driven metastasis and multidrug resistance depending on the concentration of its use.

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect.

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

Pharmacokinetics, pharmacodynamics and safety of oral formulation (CG-750) of ivaltinostat, a histone deacetylase inhibitor, compared to IV formulation (CG-745).

AIMS: CG-750 is an oral formulation of ivaltinostat, a newly developing histone deacetylase (HDAC) inhibitor. This study aimed to evaluate the pharmacokinetics (PK), pharmacodynamics (PD) and safety of an oral formulation (CG-750) of ivaltinostat compared to an intravenous (IV) formulation (CG-745). METHODS: A randomized, double-blind, placebo-controlled study was conducted in three cohorts. Subjects received either CG-745 (Cohorts 1 and 3: 125 mg; Cohort 2: 250 mg) or placebo followed by CG-750 (Cohort 1: 125 mg; Cohort 2: 375 mg; Cohort 3: 750 mg) or placebo. Blood samples for PK and PD assessment were collected up to 72 h post-dose. Histone H3 acetylation at sites K9, K9/K14 and K27 was assessed for area under the % acetylation induction versus time curve (AUEC). RESULTS: A total of 25 subjects were randomized, and 23 subjects completed the study (Cohort 1, n = 6; Cohort 2, n = 6; Cohort 3, n = 6; placebo, n = 5). The mean bioavailability of CG-750 was 10.6% (range: 4.18%-21.33%) and displayed linear PK in the dose range of 125-750 mg. The comparison of AUEC between formulations and the evaluation of the dose-AUEC relationship were inconclusive, due to the small sample sizes and significant variability observed in PD markers. All adverse events (AEs) were transient and of mild or moderate intensity. CONCLUSIONS: The oral formulation of ivaltinostat (CG-750) was generally well tolerated after a single dose. CG-750 displayed a mean bioavailability of 10.6%.

Advanced prescription of injectable anticancer drugs: Safety assessment in a European Comprehensive Cancer Centre using the risk matrix approach.

AIMS: The purpose of this work was to assess failures in the advanced prescription of parenteral anticancer agents in an adult day oncology care unit with more than 100 patients per day. METHODS: An a priori descriptive analysis was carried out by using the risk matrix approach. After defining the scope in a multidisciplinary meeting, we determined at each step the failure modes (FMs), their effects (E) and their associated causes (C). A severity score (S) was assigned to all effects and a probability of occurrence (O) to all causes. These S and O indicators, were used to obtain a criticality index (CI) matrix. We assessed the risk control (RC) of each failure in order to define a residual criticality index (rCI) matrix. RESULTS: During risk analysis, 14 FMs were detected, and 61 scenarios were identified considering all possible effects and causes. Nine situations (15%) were highlighted with the maximum CI, 18 (30%) with a medium CI, and 34 (55%) with a negligible CI. Nevertheless, among all these critical situations, only three (5%) had an rCI to process (i.e., missed dose adjustment, multiple prescriptions and abnormal biology data); the others required monitoring only. Clinicians' and pharmacists' knowledge of these critical situations enables them to manage the associated risks. CONCLUSIONS: Advanced prescription of injectable anticancer drugs appears to be a safe practice for patients when combined with risk management. The major risks identified concerned missed dose adjustment, prescription duplication and lack of consideration for abnormal biology data.

Exposure-response modelling of osimertinib in patients with non-small cell lung cancer.

AIMS: Osimertinib is a third-generation, irreversible, central nervous system-active, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with efficacy in EGFR-mutated non-small cell lung cancer (NSCLC). We assessed the relationship between plasma osimertinib levels and its efficacy and safety events. METHODS: Comprehensive pharmacokinetics exposure-response (E-R) modelling was performed utilizing steady state area under the curve (AUCss) data from first-line, ≥second-line and adjuvant studies from the osimertinib clinical development programme (20-240 mg once-daily dosing; N = 1689 patients). Analyses were conducted for survival using a proportional hazard model; for interstitial lung disease (ILD) and left ventricular ejection fraction (LVEF) events using a penalized logistic regression model and graphical analysis of potential confounding factors; and for rash and diarrhoea events using descriptive analysis. RESULTS: E-R modelling analyses indicated no clear trend of increasing efficacy with increasing osimertinib AUCss; efficacy in all exposure quartiles was significantly better than the control arm (comparator EGFR-TKI, chemotherapy or placebo) irrespective of treatment line. Model-based analysis suggested a potential relationship between increased osimertinib exposure and increased probability of ILD events, predominantly in Japanese patients. Additionally, there were increased probabilities of rash or diarrhoea with increasing osimertinib exposure. The probability of LVEF events showed overlapping confidence intervals for osimertinib ≤80 mg and control. CONCLUSIONS: E-R modelling in patients with EGFR-mutated NSCLC demonstrated that increased osimertinib exposure was unlikely to increase efficacy but may increase occurrence of certain adverse events. Hence, long-term treatment with doses ≥80 mg was not expected to provide additional benefit.

Evaluation of anticancer therapy-related dermatologic adverse events: Insights from Food and Drug Administration's Adverse Event Reporting System dataset.

BACKGROUND: New anticancer therapies have improved patient outcomes but associated dermatologic adverse events (AEs) may cause morbidity and treatment discontinuation. A comprehensive estimation of associations between cancer drugs and skin AEs is lacking. METHODS: This study utilized the Food and Drug Administartion (FDA)'s Adverse Event Reporting System database (January 2013-September 2022), with 3,399,830 reports involving 3084 drugs and 16,348 AEs. A nearest neighbor matching model was employed to select 10 controls for each case report, utilizing the cosine similarity of demographic and AE severity factors to minimize false positives/negatives. RESULTS: There were 10,698 unique anticancer drugs (n = 212) to skin AE (n = 873) pairs, of which 676 had significant reporting odds ratios (ROR) > 1, comprising 113 drugs and 144 AEs. The minimum ROR was 1.25, and 50% of associations displayed a ROR >10. The most common were rash (51 agents) and dry skin (28 drugs). Methotrexate induced the most distinct AEs (34), then mechlorethamine (33), and vemurafenib (24). Targeted therapies accounted for 49% of pairs, cytotoxic chemotherapies for 35.9%, and immunotherapies for 11%. CONCLUSIONS: A total of 113 anticancer drugs were identified as significantly associated with skin AEs, most frequently rash and dry skin. Data are likely under-reported but enable quick postmarketing identification of skin toxicity signals.

Utilizing Copper Nanoclusters as a Fluorescent Probe for Quantitative Monitoring of Doxorubicin Anticancer Drug.

Monitoring the amount of chemotherapeutic drugs in biological fluids is extremely important for dose adjustment or control of side effects during the treatment process. In this study, copper nanoclusters (Cu NCs) were synthesized via a one-pot method using ammonium citrate as the reducing agent. Cu NCs exhibited bright blue fluorescence, good optical properties and outstanding photostability. The produced Cu NCs were characterized in detail by UV‒vis absorption, fluorescence spectroscopy and transmission electron microscopy (TEM). The produced Cu NCs showed a high quantum yield of 0.97. A fluorescence system was used for doxorubicin (DOX) determination using Cu NCs as a nanoprobe. The presence of DOX decreased the fluorescence intensity of the CuNCs at 445 nm but increased the fluorescence intensity of the CuNCs at 619 nm. As a result, quantitative detection of DOX can be achieved by measuring the ratio of fluorescence intensities at 445 and 619 nm (F619/F445). The fluorescence quenching activity of the Cu NCs was determined to have a linear relationship with the amount of DOX anticancer drug in the range of 1-15 ppb, and the usability of the Cu NCs as a sensor for detection in biological fluids was demonstrated. It was determined that this method can be used to measure the amount of DOX in biological samples effectively.

Cytotoxic and molecular differences of anticancer agents on 2D and 3D cell culture.

BACKGROUND: Cancer and multidrug resistance are regarded as concerns related to poor health outcomes. It was found that the monolayer of 2D cancer cell cultures lacks many important features compared to Multicellular Tumor Spheroids (MCTS) or 3D cell cultures which instead have the ability to mimic more closely the in vivo tumor microenvironment. This study aimed to produce 3D cell cultures from different cancer cell lines and to examine the cytotoxic activity of anticancer medications on both 2D and 3D systems, as well as to detect alterations in the expression of certain genes levels. METHOD: 3D cell culture was produced using 3D microtissue molds. The cytotoxic activities of colchicine, cisplatin, doxorubicin, and paclitaxel were tested on 2D and 3D cell culture systems obtained from different cell lines (A549, H1299, MCF-7, and DU-145). IC50 values were determined by MTT assay. In addition, gene expression levels of PIK3CA, AKT1, and PTEN were evaluated by qPCR. RESULTS: Similar cytotoxic activities were observed on both 3D and 2D cell cultures, however, higher concentrations of anticancer medications were needed for the 3D system. For instance, paclitaxel showed an IC50 of 6.234 µM and of 13.87 µM on 2D and 3D H1299 cell cultures, respectively. Gene expression of PIK3CA in H1299 cells also showed a higher fold change in 3D cell culture compared to 2D system upon treatment with doxorubicin. CONCLUSION: When compared to 2D cell cultures, the behavior of cells in the 3D system showed to be more resistant to anticancer treatments. Due to their shape, growth pattern, hypoxic core features, interaction between cells, biomarkers synthesis, and resistance to treatment penetration, the MCTS have the advantage of better simulating the in vivo tumor conditions. As a result, it is reasonable to conclude that 3D cell cultures may be a more promising model than the traditional 2D system, offering a better understanding of the in vivo molecular changes in response to different potential treatments and multidrug resistance development.