High-resolution laser ablation-inductively coupled plasma-mass spectrometry imaging of cisplatin-induced nephrotoxic side effects

Evaluation of two-phase sample transport upon ablation of gelatin as a proxy for soft biological matrices using nanosecond laser ablation - inductively coupled plasma - mass spectrometry

BACKGROUND

Recent papers on LA-ICP-MS have reported that certain elements are transported in particulate form, others in gaseous form and still others in a combination of both upon ablation of C-based materials. These two phases display different transport behaviour characteristics, potentially causing smearing in elemental maps, and could be processed differently in the ICP which raises concerns as to accuracy of quantification and emphasizes the need for matrix-matching of external standards. This work aims at a better understanding of two-phase sample transport by evaluating the peak profile changes observed upon varying parameters such as laser energy density and wavelength.

RESULTS

It is demonstrated that upon ablation of gelatin, elements are transported predominantly in particulate phase, but already at low laser energy density, a significant fraction of some elements is transported in the gaseous phase, which is even more expressed at higher energy density. This behaviour is element-specific since the ratio of the signal intensity for the analyte element transported in gas phase to the total signal intensity was 0 % for 23Na, 43 % for 66Zn and as high as 95 % for 13C using a 193 nm laser. The results also suggest an effect of the laser wavelength, as all elements show either the same or higher amount of gas phase formation upon ablating with 213 nm versus 193 nm. It was even established that elements that fully occur in particulate form upon ablation using 193 nm laser radiation are partly converted into gaseous phase when using 213 nm.

SIGNIFICANCE

This work provides a thorough investigation of the underexposed phenomenon of two-phase sample transport upon ablation of biological samples upon via LA-ICP-MS. It is shown that for some elements a fraction of the ablated material is converted and transported in the gas phase, which can lead to significant smearing effects. As such, it is important to evaluate element-specific peak profiles on beforehand and, if necessary, adapt instrument settings and slow down data acquisition.

High-Throughput Single-Cell Analysis of Nanoparticle-Cell Interactions

Understanding nanoparticle-cell interactions at single-nanoparticle and single-cell resolutions is crucial to improving the design of next-generation nanoparticles for safer, more effective, and more efficient applications in nanomedicine. This review focuses on recent advances in the continuous high-throughput analysis of nanoparticle-cell interactions at the single-cell level. We highlight and discuss the current trends in continual flow high-throughput methods for analyzing single cells, such as advanced flow cytometry techniques and inductively coupled plasma mass spectrometry methods, as well as their intersection in the form of mass cytometry. This review further discusses the challenges and opportunities with current single-cell analysis approaches and provides proposed directions for innovation in the high-throughput analysis of nanoparticle-cell interactions.

Advances in mass spectrometry imaging for toxicological analysis and safety evaluation of pharmaceuticals

Safety issues caused by pharmaceuticals have frequently occurred worldwide, posing a tremendous threat to human health. As an essential part of drug development, the toxicological analysis and safety evaluation is of great significance. In addition, the risk of pharmaceuticals accumulation in the environment and the monitoring of the toxicity from natural medicines have also received ongoing concerns. Due to a lack of spatial distribution information provided by common analytical methods, analyses that provide spatial dimensions could serve as complementary safety evaluation methods for better prediction and evaluation of drug toxicity. With advances in technical solutions and software algorithms, mass spectrometry imaging (MSI) has received increasing attention as a popular analytical tool that enables the simultaneous implementation of qualitative, quantitative, and localization without complex sample pretreatment and labeling steps. In recent years, MSI has become more attractive, powerful, and sensitive and has been applied in several scientific fields that can meet the safety assessment requirements. This review aims to cover a detailed summary of the various MSI technologies utilized in the biomedical and pharmaceutical area, including technical principles, advantages, current status, and future trends. Representative applications and developments in the safety-related issues of different pharmaceuticals and natural medicines are also described to provide a reference for pharmaceutical research, improve rational clinical medicine use, and ensure public safety.

Anticancer Peptide Prediction via Multi-Kernel CNN and Attention Model

Background: Modern lifestyles mean that people are more likely to suffer from some form of cancer. As anticancer peptides can effectively kill cancer cells and play an important role in fighting cancer, they have been a subject of increasing research interest. Methods: This study presents a useful tool to identify the anticancer peptides based on a multi-kernel CNN and attention model, called ACP-MCAM. This model can automatically learn adaptive embedding and the context sequence features of ACP. In addition, to obtain better interpretability and integrity, we visualized the model. Results: Benchmarking comparison shows that ACP-MCAM significantly outperforms several state-of-the-art models. Different encoding schemes have different impacts on the performance of the model. We also studied tmethod parameter optimization. Conclusion: The ACP-MCAM can integrate multi-kernel CNN and self-attention mechanism, which outperforms the previous model in identifying anticancer peptides. It is expected that the work will provide new research ideas for anticancer peptide prediction in the future. In addition, this work will promote the development of the interdisciplinary field of artificial intelligence and biomedicine.

Cisplatin Uptake in Macrophage Subtypes at the Single-Cell Level by LA-ICP-TOFMS Imaging

A high-throughput laser ablation–inductively coupled plasma–time-of-flight mass spectrometry (LA-ICP-TOFMS) workflow was implemented for quantitative single-cell analysis following cytospin preparation of cells. For the first time, in vitro studies on cisplatin exposure addressed human monocytes and monocyte-derived macrophages (undifferentiated THP-1 monocytic cells, differentiated M0 macrophages, as well as further polarized M1 and M2 phenotypes) at the single-cell level. The models are of particular interest as macrophages comprise the biggest part of immune cells present in the tumor microenvironment and play an important role in modulating tumor growth and progression. The introduced bioimaging workflow proved to be universally applicable to adherent and suspension cell cultures and fit-for-purpose for the quantitative analysis of several hundreds of cells within minutes. Both, cross-validation of the method with single-cell analysis in suspension for THP-1 cells and with LA-ICP-TOFMS analysis of adherent M0 cells grown on chambered glass coverslips, revealed agreeing platinum concentrations at the single-cell level. A high incorporation of cisplatin was observed in M2 macrophages compared to the M0 and M1 macrophage subtypes and the monocyte model, THP-1. The combination with bright-field images and monitoring of highly abundant endogenous elements such as phosphorus and sodium at a high spatial resolution allowed assessing cell size and important morphological cell parameters and thus straightforward control over several cell conditions. This way, apoptotic cells and cell debris as well as doublets or cell clusters could be easily excluded prior to data evaluation without additional staining.

Manufacturing of Plant-Based Bioactive Peptides Using Enzymatic Methods to Meet Health and Sustainability Targets of the Sustainable Development Goals

Due to the rapid growth in the global population, the consumption of animal-based food products/food compounds has been associated with negative implications for food sustainability/security. As a result, there is an increasing demand for the development of plant-based food and compounds as alternatives. Meanwhile, a growing number of studies report the health benefits of food protein-based peptides prepared via enzymatic hydrolysis and exhibiting biological properties such as antioxidant, antihypertensive, anti-thrombotic, and antidiabetic activities. However, the inherent bitterness of some peptides hinders their application in food products as ingredients. This article aims to provide the latest findings on plant-based bioactive peptides, particularly their health benefits, manufacturing methods, detection and qualification of their bitterness properties, as well as debittering methods to reduce or eliminate this negative sensory characteristic. However, there is still a paucity of research on the biological property of debittered peptides. Therefore, the role of plant protein-derived bioactive peptides to meet the health targets of the Sustainable Development Goals can only be realised if advances are made in the industrial-scale bioprocessing and debittering of these peptides.

MS imaging of multicellular tumor spheroids and organoids as an emerging tool for personalized medicine and drug discovery

MS imaging (MSI) is a powerful tool in drug discovery because of its ability to interrogate a wide range of endogenous and exogenous molecules in a broad variety of samples. The impressive versatility of the approach, where almost any ionizable biomolecule can be analyzed, including peptides, proteins, lipids, carbohydrates, and nucleic acids, has been applied to numerous types of complex biological samples. While originally demonstrated with harvested organs from animal models and biopsies from humans, these models are time consuming and expensive, which makes it necessary to extend the approach to 3D cell culture systems. These systems, which include spheroid models, prepared from immortalized cell lines, and organoid cultures, grown from patient biopsies, can provide insight on the intersection of molecular information on a spatial scale. In particular, the investigation of drug compounds, their metabolism, and the subsequent distribution of their metabolites in 3D cell culture systems by MSI has been a promising area of study. This review summarizes the different ionization methods, sample preparation steps, and data analysis methods of MSI and focuses on several of the latest applications of MALDI-MSI for drug studies in spheroids and organoids. Finally, the application of this approach in patient-derived organoids to evaluate personalized medicine options is discussed.

LincRNA-p21 Inhibits Cisplatin-Induced Apoptosis of Human Renal Proximal Tubular Epithelial Cells by Sponging miR-449a

INTRODUCTION

LincRNA-p21 is predicted to interact with miR-449a, which plays a protective role in cisplatin-induced acute kidney injury (CIA).

OBJECTIVE

This study aimed to analyze the involvement of lincRNA-p21 in breast cancer patients with CIA.

METHODS

Levels of lincRNA-p21 in plasma from CIA, triple negative breast cancer, and control groups were measured by performing RT-qPCR. The potential interaction between lincRNA-p21 and miR-449a was first predicted by RT-qPCR. The relationship between lincRNA-p21 and miR-449a was analyzed by overexpression experiment.

RESULTS

We found that lincRNA-p21 is downregulated in CIA. Dual luciferase activity assay showed that lincRNA-p21 and miR-449a can interact with each other, while overexpression of lincRNA-p21 and miR-449a failed to affect the expression of each other. In human renal proximal tubular epithelial cells (HRPTEpCs), cisplatin led to the upregulated miR-449a but downregulated lincRNA-p21. Interestingly, lincRNA-p21 overexpression led to reduced enhancing effects of miR-449a on the cisplatin-induced apoptosis of HRPTEpCs.

CONCLUSION

Therefore, lincRNA-p21 is downregulated in CIA and may sponge miR-449a to inhibit cisplatin-induced apoptosis of HRPTEpCs.

Micro-droplet-based calibration for quantitative elemental bioimaging by LA-ICPMS

In this work, a novel standardization strategy for quantitative elemental bioimaging is evaluated. More specifically, multi-element quantification by laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS) is performed by multi-point calibration using gelatin-based micro-droplet standards and validated using in-house produced reference materials. Fully automated deposition of micro-droplets by micro-spotting ensured precise standard volumes of 400 ± 5 pL resulting in droplet sizes of around 200 μm in diameter. The small dimensions of the micro-droplet standards and the use of a low-dispersion laser ablation setup reduced the analysis time required for calibration by LA-ICPMS significantly. Therefore, as a key advance, high-throughput analysis (pixel acquisition rates of more than 200 Hz) enabled to establish imaging measurement sequences with quality control- and standardization samples comparable to solution-based quantification exercises by ICP-MS. Analytical figures of merit such as limit of detection, precision, and accuracy of the calibration approach were assessed for platinum and for elements with biological key functions from the lower mass range (phosphorus, copper, and zinc). As a proof-of-concept application, the tool-set was employed to investigate the accumulation of metal-based anticancer drugs in multicellular tumor spheroid models at clinically relevant concentrations.

Comparisons of segment-specific toxicity of platinum-based agents and cadmium using S1, S2, and S3 cells derived from mouse kidney proximal tubules

Renal toxicants such as cisplatin and cadmium cause segment-specific damages in kidney proximal tubules. Recently, we established an in vitro experimental system for evaluating segment-specific toxicity and transport of chemicals using immortalized S1, S2, and S3 cells derived from the S1, S2, and S3 regions of mouse kidney proximal tubules. In the present study, we examined the toxicity and accumulation of cisplatin, carboplatin, oxaliplatin, and cadmium in S1, S2, and S3 cells. We found that not only cisplatin but also carboplatin and oxaliplatin exhibited higher lethal toxicity in S3 cells than in S1 and S2 cells. At sublethal doses, cisplatin showed delayed induction of Kim-1 and clusterin on days 3 and 6, which may reflect the latent renal toxicity of cisplatin in vivo. The high sensitivities of S3 cells to the platinum-based agents were not due to the high accumulation of Pt in S3 cells. Exposure to cadmium resulted in similar toxicity among these cells, suggesting that S3 cells were not sensitive to any renal toxicants. Thus, the utilization of S1, S2, and S3 cells may provide a useful tool for the in vitro evaluation of the proximal tubule segment-specific toxicity of chemicals.

Molecular docking, pharmacokinetic studies, and in vivo pharmacological study of indole derivative 2-(5-methoxy-2-methyl-1H-indole-3-yl)-N'-[(E)-(3-nitrophenyl) methylidene] acetohydrazide as a promising chemoprotective agent against cisplatin induced organ damage

Cisplatin is an efficient anticancer drug against various types of cancers however, its usage involves side effects. We investigated the mechanisms of action of indole derivative, 2-(5-methoxy-2-methyl-1H-indol-3-yl)-N'-[(E)-(3-nitrophenyl) methylidene] acetohydrazide (MMINA) against anticancer drug (cisplatin) induced organ damage using a rodent model. MMINA treatment reversed Cisplatin-induced NO and malondialdehyde (MDA) augmentation while boosted the activity of glutathione peroxidase (GPx), and superoxide dismutase (SOD). The animals were divided into five groups (n = 7). Group1: Control (Normal) group, Group 2: DMSO group, Group 3: cisplatin group, Group 4: cisplatin + MMINA group, Group 5: MMINA group. MMINA treatment normalized plasma levels of biochemical enzymes. We observed a significant decrease in CD4+COX-2, STAT3, and TNF-α cell population in whole blood after MMINA dosage. MMINA downregulated the expression of various signal transduction pathways regulating the genes involved in inflammation i.e. NF-κB, STAT-3, IL-1, COX-2, iNOS, and TNF-α. The protein expression of these regulatory factors was also downregulated in the liver, kidney, heart, and brain. In silico docking and dynamic simulations data were in agreement with the experimental findings. The physiochemical properties of MMINA predicted it as a good drug-like molecule and its mechanism of action is predictably through inhibition of ROS and inflammation.

Low expression of FXYD5 reverses the cisplatin resistance of epithelial ovarian cancer cells

OBJECTIVE

To investigate the effect of the downregulation of FXYD domain-containing ion transport regulator 5 (FXYD5) on the cisplatin resistance (CisR) of epithelial ovarian cancer (EOC) cells.

METHODS

A2780-CisR and SKOV3-CisR cells were obtained through repeated administrations of different cisplatin concentrations, and the half-maximal inhibition concentration (IC50) was calculated by MTT assays. After transfection with FXYD5 siRNA-1 and FXYD5 siRNA-2, the IC50 values of the A2780-CisR and SKOV3-CisR cells were also detected by the MTT method. Cell proliferation, migration, invasion and apoptosis were evaluated through 5-ethynyl-2'-deoxyuridine (EdU) DNA synthesis, wound healing, Transwell invasion and Annexin-V-FITC/PI dual-staining assays, respectively. qRT-PCR and Western blotting were conducted to detect mRNA and protein expression.

RESULTS

Compared with the sensitive parental cells, the A2780-CisR and SKOV3-CisR cells had increased IC50 and FXYD5 expression. FXYD5 siRNA reduced the IC50 value of cisplatin in the A2780-CisR and SKOV3-CisR cells and decreased the expression of ABCG2 (BCRP) and ABCB1 (MDR1). In addition, FXYD5 inhibition reduced the invasion and migration of the A2780-CisR and SKOV3-CisR cells, with upregulation of E-cadherin and downregulation of Snail and Vimentin. Both FXYD5 siRNA-1 and FXYD5 siRNA-2 inhibited the proliferation and promoted the apoptosis of the A2780-CisR and SKOV3-CisR cells with reduced Ki-67 and increased caspase-3.

CONCLUSION

FXYD5 downregulation may reduce the invasion, migration and EMT formation of EOC cells to increase their sensitivity to cisplatin chemotherapy by inhibiting cell proliferation and promoting cell apoptosis.

Mass spectrometry techniques for imaging and detection of metallodrugs

Undoubtedly, metallomic approaches based on mass spectrometry have evolved into essential tools supporting the drug development of novel metal-based anticancer drugs. This article will comment on the state-of-the-art instrumentation and highlight some of the recent analytical advances beyond routine, especially focusing on the latest developments in inductively coupled plasma-mass spectrometry (ICP-MS). Mass spectrometry-based bioimaging and single-cell methods will be presented, paving the way to exciting investigations of metal-based anticancer drugs in heterogeneous and structurally, as well as functionally complex solid tumor tissues.

Toward a comprehensive study for multielemental quantitative LA-ICP MS bioimaging in soft tissues

Quantitative localization of metals in biological tissue sections is critical to obtain insight into metal toxicity mechanisms or their beneficial characteristics. This study presents the development of a quantitative LA-ICP MS bioimaging methodology based on the polymer film strategy and internal standardization. To maximize the number of elements mapped, an aqueous soluble polymer (dextran) was selected. Among the elements studied, the great majority (eight out eleven), i.e., Co, Ni, Cu, Zn, Se, Mo, Cd and Pt, exhibited linear regression after LA-ICP MS analysis of metal-spiked polymer standards. Methodology performances were carefully assessed as a function of the three internal standards (In, Rh and Ir) considered, the analytical operational conditions (ICP power, addition of O₂ to ICP, and laser fluency) and the thickness of the biological tissue section. The results indicated that three groups (Co, Mo; Ni, Cu, Pt; and Zn, Se, Cd) of elements could be distinguished from their analytical response as a function of analytical conditions and the internal standard. These different element behaviors appeared to be mainly First Ionization Potential dependent (FIP). For elements with lower FIP (Co, Ni, Cu, Mo and Pt), differential responses due to carbon load in the ICP MS plasma could be efficiently corrected as a function of analytical conditions. Matrix effects were more pronounced for higher FIP elements (i.e., Zn, Cd and Se), and analysis of <10-μm thin sections without the addition of O₂ to ICP MS plasma is recommended. LODs are in the range of 0.1-0.5 μg g^-1 for Co, Mo, Cu, Ni, Pt and Cd as well as 0.9 and 1 μg g^-1 for Zn and Se, respectively. The methodology was validated by means of a homemade metal-spiked kidney homogenate analyzed by LA-ICP MS imaging, and Co, Ni, Cu, Mo, and Pt provided the closest concentrations (5-29% bias) to the target values determined by ICP MS after mineralization. The methodology was applied to two types of clinical human samples undergoing different sample preparation protocols that did not affect internal standard homogeneity in the polymer film. This methodology is the first reported for the quantitative bioimaging of eight elements simultaneously.

Quantitative Visualization of Lanthanum Accumulation in Lanthanum Carbonate-Administered Human Stomach Tissues Using Mass Spectrometry Imaging

Platinum, a transition metal that is widely used in anti-cancer agents, also results in the development of nephropathy due to severe adverse reactions caused by platinum-induced nephrotoxicity. Reports on imaging with metals other than platinum remain are limited, even in preclinical studies. Furthermore, most of these are case reports, and the relationship between the distribution of the metal and clinical observations in human samples is not well understood. Here we report on visualizing lanthanum (¹³⁹La), a component of Fosrenol, which is usually used for the treatment of hyperphosphatemia. Gastric inflammation, also known as hemorrhagic gastritis, is the main adverse event caused by Fosrenol. To conduct this study, ¹³⁹La was visualized in gastric biopsy samples obtained from a patient using quantitative laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). We also compared the distribution of ¹³⁹La in tissue and histochemical results. The areas where ¹³⁹La accumulated corresponded to the macrophage-positive areas observed in immunohistochemistry studies using an anti-CD68 antibody. In contrast, we observed a debris-like crystal morphology in hematoxylin and eosin staining tissues. The debris was also associated with ¹³⁹La accumulation. The abnormal accumulation of ¹³⁹La crystals caused the observed inflammation. This phenomenon was previously characterized, but this is the first report in which ¹³⁹La distribution and histochemical results are compared using LA-ICP-MS.

Evaluation of 10 Urinary Biomarkers for Renal Safety With 5 Nephrotoxicants in Nonhuman Primates

To date, there has been very little published data evaluating the performance of novel urinary kidney biomarkers in nonhuman primates (NHPs). To assess the biomarker performance and characterize the corresponding histomorphologic patterns of tubular renal injury in the NHP, several studies were conducted using mechanistically diverse nephrotoxicants including cefpirome, cisplatin, naproxen, cyclosporine, and a combination of gentamicin with everninomicin. An evaluation of 10 urinary biomarkers (albumin, clusterin, cystatin C, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, N-acetyl-β-D-glucosaminidase, osteopontin, retinol binding protein 4 and total protein) was performed on urine collected from these studies. Each of these 5 treatments resulted in kidney proximal tubule injury of various severities. Histomorphologic features observed following treatment were generally consistent with analogous drug-induced changes in humans described in the literature. Most of the analyzed biomarkers were able to detect the injury earlier and with greater sensitivity than blood urea nitrogen and serum creatinine. Across all studies, KIM-1 and clusterin showed the highest overall performance. Differences in the patterns of biomarker responsiveness were noted among certain studies that may be informing tubular injury severity and recovery potential, underlying histopathologic processes, and prognosis. These findings demonstrate the utility of urinary kidney translational safety biomarkers in NHPs and provide additional supporting evidence for translating these biomarkers for use in clinical trial settings to further ensure patient safety.

Interactions of Cisplatin and Daunorubicin at the Chromatin Level

Unexpectedly, the widely used anticancer agents Cisplatin (Cis-Pt) and Daunorubicin (Dauno) exhibited cell type- and concentration-dependent synergy or antagonism in vitro. We attempted to interpret these effects in terms of the changes elicited by the drugs in the chromatin, the target held primarily responsible for the cytotoxicity of both agents. We measured the effect of Cis-Pt on the levels of Dauno in different cell compartments, the effect of Cis-Pt on Dauno-induced nucleosome eviction, and assessed the influence of Dauno on DNA platination in flow- and laser scanning cytometry as well as in laser ablation-inductively coupled plasma-mass spectrometry assays. We show that the two drugs antagonize each other through a decrease of interstrand crosslinks upon co-treatment with Dauno, and also via the diminished Dauno uptake in the presence of Cis-Pt, and both effects are observed already at low Dauno concentrations. At high Dauno concentrations synergy becomes dominant because histone eviction by Dauno intercalation into the DNA is enhanced in the presence of co-treatment with Cis-Pt. These interactions may have an impact on the efficacy of combination treatment protocols, considering the long retention time of DNA adducts formed by both agents.

Laser ablation-ICP-TOFMS imaging of germ cell tumors of patients undergoing platinum-based chemotherapy

A low dispersion laser ablation setup in combination with inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS) was applied to clinical samples of patients undergoing platinum-based chemotherapy.

The Opportunities and Use of Imaging to Measure Target Engagement

Lack of efficacy and poor safety outcomes are deemed to be the greatest causes of clinical failure of novel therapeutics. The use of biomarkers that give accurate information on target engagement, providing confidence that pharmacological activity in the target organ is being achieved, is key in optimizing clinical success. Without a measurement of target engagement, it can be very difficult to discern the basis for any lack of efficacy of a drug molecule within the pharmaceutical industry. Target engagement can be measured in both an in vitro and in vivo setting, and in recent years imaging measurements have been used frequently in drug discovery and development to assess target engagement and receptor occupancy in both human and animal models. From this perspective, we assess and look at the advancements in both in vivo and ex vivo imaging to demonstrate the enormous potential that imaging has as an application to provide a greater understanding of target engagement with a correlative therapeutic impact.

Protective effect of avenanthramides against cisplatin induced nephrotoxicity in rats

OBJECTIVE

The aim of this study is to inspect the ameliorative effect of avenanthramides (AVA) on CP nephrotoxicity in Sprague-Dawley rats.

MATERIALS AND METHODS

Blood samples were collected for the determination of hematological parameters. Creatinine, blood urea nitrogen (BUN), and tumor necrosis factor-α (TNF-α) were measured in serum. Specimens from both kidneys were taken for histopathological examinations.

RESULTS

Administration of AVA resulted in significant decrease in the level of creatinine and TNF-α when compared with CP group. Histopathologically, CP-induced vacuolar degeneration and necrosis of the kidney tubules. Administration of AVA ameliorates the histopathological alterations induced by CP.

CONCLUSION

AVA can be considered as a protective agent for kidneys during administration of CP. The protective effect of AVA may be related to the reduction of TNF-α which implicated in the pathogenesis of CP nephrotoxicity.

High-resolution imaging and single-cell analysis via laser ablation-inductively coupled plasma-mass spectrometry for the determination of membranous receptor expression levels in breast cancer cell lines using receptor-specific hybrid tracers

This work evaluates the possibility of placement of high-resolution imaging and single-cell analysis via laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) within precision medicine by assessing the suitability of LA-ICP-MS as a micro-analytical technique for the localization and quantification of membranous receptors in heterogeneous cell samples that express both the membrane-bound receptors C-X-C chemokine receptor type 4 (CXCR4) and epidermal growth factor receptor (EGFR). Staining of the breast cancer cell lines MDA-MB-231 X4 and MDA-MB-468 was achieved using receptor-specific hybrid tracers, containing both a fluorophore and a DTPA single-lanthanide chelate. Prior to LA-ICP-MS imaging, fluorescence confocal microscopy (FCM) imaging was performed to localize the receptors, hereby enabling direct comparison. Based on the different expression levels of CXCR4 and EGFR, a distinction could be made between the cell lines using both imaging modalities. Furthermore, FCM and LA-ICP-MS demonstrated complementary characteristics, as a more distinct discrimination could be made between both cell lines based on the EGFR-targeting hybrid tracer via LA-ICP-MS, due to the intrinsic CXCR4-related green fluorescent protein (GFP) signal present in the MDA-MB-231 X4 cells. Employing state-of-the-art LA-ICP-MS instrumentation in bidirectional area scanning mode for sub-cellular imaging of MDA-MB-231 X4 cells enabled the specific binding of the CXCR4-targeting hybrid tracer to the cell membrane to be clearly demonstrated. The stretching of cells over the glass substrate led to a considerably higher signal response for pixels at the cell edges, relative to the more central pixels. The determination of the expression levels of CXCR4 and EGFR for the MDA-MB-468 cell line was performed using LA-ICP-MS single-cell analysis (sc-LA-ICP-MS) and external calibration, based on the quantitative ablation of Ho-spiked dried gelatin droplet standards. Additionally, a second calibration approach was applied based on spot ablation of highly homogeneous dried gelatin gels in combination with the determination of the ablated volume using atomic force microscopy (AFM) and yielded results which were in good agreement with the expression levels determined via flow cytometry (FC) and mass cytometry (MC). Hybrid tracers enable a direct comparison between (i) FCM and LA-ICP-MS imaging for the evaluation of the microscopic binding pattern and between (ii) FC, MC and sc-LA-ICP-MS for the quantification of receptor expression levels in single cells.

A novel helper qPCR system for platinum detection via Pt-DNA coordination

A novel real-time polymerase chain reaction (qPCR) platform for the simple and robust detection of platinum is described for the first time. Compared with conventional qPCR, a helper template, which is related to the active template for performing qPCR, was introduced in our helper qPCR system. Several guanine (G) bases were introduced in the helper template to obtain a platinum-responsive on/off switch based on G-Pt-G coordination. Because of the helper template, a slight change in platinum concentration would significantly change the signal in the qPCR. This novel helper qPCR technique easily detects platinum with high sensitivity (1 ng/mL) and selectivity over other metal ions. Therefore, it will be a promising technique for the detection of platinum in biomedical and environmental samples.

Brief Overview: Assessment of Compound-induced Acute Kidney Injury Using Animal Models, Biomarkers, and In Vitro Platforms

The inability to unequivocally predict translatable drug-induced kidney injury in nonclinical studies during pharmacological development is evidenced by drug attrition in human clinical trials. Eight urinary proteins have been qualified as renal safety biomarkers for limited context of use in nonclinical drug development studies in rats. Formal qualification of human renal safety biomarkers is pending the submission of data from prospective clinical trials and analyses of biomarker performance to the Food and Drug Administration and European Medicines Agency by the Foundation for the National Institutes of Health and Predictive Safety Testing Consortium's Nephrotoxicity Working Group. In vitro kidney platforms may be leveraged to investigate the potential risk of compound-induced acute kidney injury and/or dysfunction. The early assessment of drug-related kidney safety profiles using biomarker-level changes in animal models and in vitro platforms could significantly reduce renal safety-related drug attrition; yet, there are no well-validated in vitro systems to enable comprehensive investigations of compound-induced nephrotoxicity. Thus, histopathology remains the gold standard for diagnosing nephron-specific damage. Traditional and emerging biomarker panels should be combined with histopathology and/or cytopathology to enable early identification of compound-induced kidney injury.

Nephrotoxicity Evaluation on Cisplatin Combined with 5-HT3 Receptor Antagonists: A Retrospective Study

Objective

5-HT₃ receptor antagonist (ondansetron) has been reported to have nephrotoxic effect when combined with cisplatin in mice; however, little evidence exists in explaining its nephrotoxic effects on patients. The aim of this present study was to investigate whether 5-HT₃ receptor antagonist could enhance or aggravate the incidence of cisplatin-induced nephrotoxicity in patients.

Methods

We retrospectively reviewed 600 tumor patients which were treated with cisplatin (⩾60 mg/m²) as a first-time chemotherapy and combined with 5-HT₃ receptor antagonist (i.e., ondansetron, tropisetron, or ramosetron, each kind of 5-HT₃ receptor antagonist contains 200 cases) between January 2010 and December 2015. Cisplatin dosing, the baseline creatinine clearance, and other independent risk factors such as patient's age, sex, PS score, and weight associated with nephrotoxicity were evaluated in a multivariable model.

Results

The incidence of Grade ⩾ 2 serum creatinine elevation in cisplatin + ondansetron group was significantly higher than cisplatin + tropisetron group (P = 0.04), but no significant difference was found between cisplatin + ondansetron group and cisplatin + ramosetron group (P = 0.3). It was also found that cisplatin dosage and tumor type were independent risk factors in the development of nephrotoxicity.

Conclusion

Higher cisplatin dosage and regular use of ondansetron combined with cisplatin are more likely to increase the incidence of nephrotoxicity; tropisetron showed the relatively mild effect on kidney function, suggesting that tropisetron is a preferable alternative in the process of cisplatin chemotherapy.

Bioimaging of isosteric osmium and ruthenium anticancer agents by LA-ICP-MS

Two isosteric organometallic drug candidates revealed distinct in vivo antitumour activities and spatial distributions in mouse tissues.

Anticancer activity of complexes of the third row transition metals, rhenium, osmium, and iridium

A summary of recent developments on the anticancer activity of complexes of rhenium, osmium, and iridium is described.

Bioactive Peptides

The increased consumer awareness of the health promoting effects of functional foods and nutraceuticals is the driving force of the functional food and nutraceutical market. Bioactive peptides are known for their high tissue affinity, specificity and efficiency in promoting health. For this reason, the search for food-derived bioactive peptides has increased exponentially. Over the years, many potential bioactive peptides from food have been documented; yet, obstacles such as the need to establish optimal conditions for industrial scale production and the absence of well-designed clinical trials to provide robust evidence for proving health claims continue to exist. Other important factors such as the possibility of allergenicity, cytotoxicity and the stability of the peptides during gastrointestinal digestion would need to be addressed. This review discusses our current knowledge on the health effects of food-derived bioactive peptides, their processing methods and challenges in their development.