Platinum-induced neurotoxicity: A review of possible mechanisms

Unraveling the ozone impact and oxidative stress on the nervous system

Ozone (O₃), a potent oxidant, can penetrate the body through breathing, generating reactive oxygen species (ROS) and triggering inflammatory processes. Oxidative stress, an imbalance between the production of ROS and the body's antioxidant capacity, plays a crucial role in the pathophysiology of various neurodegenerative diseases. This phenomenon can negatively impact the Central Nervous System (CNS), inducing structural and functional alterations that contribute to the development of neurological pathologies. This review examines how O₃-induced oxidative stress affects the nervous system by analyzing existing literature on the involved molecular mechanisms and potential antioxidant systems to mitigate its effects. Through a comprehensive review of experimental studies, our objective is to shed light on the interaction between O₃ and the nervous system, as well as its signaling pathways and altered genes, providing a foundation for future research in this field. Several studies have demonstrated that prolonged exposure to O₃ leads to increased expression of reactive oxygen species, causing alterations in the blood-brain barrier and damage to astrocytes and microglia. These effects can lead to an increase in the production of proinflammatory cytokines, neurotoxins, and genes, exacerbating neuronal damage and accelerating the progression of neurodegenerative diseases such as Alzheimer's, Parkinson's, and other neurological disorders. The results of this review suggest that exposure to O₃ may induce oxidative damage to the nervous system, which could have significant implications for public health.

Quantifying Intracellular Platinum Accumulation Using Inductively Coupled Mass Spectrometry

The platinum-based anticancer drug cisplatin and its analog carboplatin are the most used chemotherapeutic agents worldwide. It is estimated that approximately half of all cancer patients are treated with platinum drugs at some point during the therapy regimen. Cisplatin covalently binds to purine nucleobases to form DNA adducts. Cisplatin therapy is faced with two key challenges. First, despite the initial response, many patients develop cisplatin resistance. Reduced cellular accumulation of cisplatin is one common cause of therapy resistance. Second, cisplatin treatment causes general cytotoxicity, leading to severe side effects. Monitoring the subcellular concentration of platinum chemotherapeutics will help yield clinical efficacy with the minimum possible dose. Inductively coupled plasma-mass spectrometry (ICP-MS) is an analytical technique to quantify the elemental composition of various types of liquified bulk samples with high sensitivity. This article describes quantifying cisplatin accumulation in chromatin and total cell lysate using ICP-MS. The method involves treating cells with cisplatin, isolating RNA-free DNA, digesting samples, ICP-MS instrumentation, and data analysis. Although we describe these steps in one cancer cell line, the protocol can be adapted to any cell line or tissue. The protocol should be a valuable resource for investigators interested in accurate measurement of subcellular concentration of platinum and other metallo-drugs. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Cell culture conditions for A2780 cells and cisplatin treatment Basic Protocol 2: Isolating cellular fractions and sample quantitation Basic Protocol 3: Sample digestion, ICP-MS data collection, and analysis.

Earnings and work loss after colon and rectal cancer: a Swedish nationwide matched cohort study

Background

Colorectal cancer is common and prognosis is improving. The conditions of survivors of treatment, including financial consequences, are thus important. The aim of this study was to quantify loss of earnings and work loss in working-age patients with colon and rectal cancer relative to matched comparators.

Methods

The study utilised data from the CRCBaSe database that is generated from the nationwide Swedish ColoRectal Cancer Register and includes data from several Swedish nationwide registers. The study period was 1995-2020 for rectal cancer patients and 2007-2020 for colon cancer patients. A retrospective population-based nationwide cohort study on earnings, disposable income, and work loss, in survivors of stage I-III colorectal cancer treatment was undertaken. Median regression was used to analyse earnings and disposable income, and logistic regression to analyse the probability of work loss.

Findings

A cohort of 8863 colorectal cancer survivors diagnosed before 2017 and 52,514 comparators matched on birth year, legal sex, and county of residence, was analysed. There was a clear reduction in earnings between the calendar year prior to and the calendar year after diagnosis, from € 31,319 to € 23,924 for colon cancer patients and from € 32,636 to € 22,647 for rectal cancer patients, and earnings never fully recovered during the 5-year follow-up. Disposable income was practically unaltered. The probability of work loss increased in the calendar year of diagnosis, from 29.8% to 25.3% the previous year to 83.3% and 84.4% for colon and rectal cancer patients respectively, and never fully recovered. The probability of work loss was similar between colon and rectal cancer survivors, but was higher among patients with rectal cancer who had received neoadjuvant therapy.

Interpretation

This study shows that despite an extensive welfare system providing maintained disposable income, there is a financial burden in the form of increased risk of work loss and a reduction in earnings among survivors of colorectal cancer.

Funding

The study was supported by the Swedish Cancer Society, the Swedish Cancer and Allergy Foundation, and the Stockholm Cancer Society, and supported by grants provided by the Regional Agreement on Medical Training and Clinical Research (ALF) between the Stockholm County Council and Karolinska Institutet.

Neurological adverse events associated with oxaliplatin: A pharmacovigilance analysis based on FDA adverse event reporting system

Objective

This study aimed to explore the neurological adverse events of oxaliplatin through the Food and Drug Administration Adverse Event Reporting System (FAERS) database and to provide reference for safe clinical drug use.

Methods

The adverse events report data of oxaliplatin from the first quarter of 2019 (1 January 2019) to the third quarter of 2023 (30 September 2023) were extracted from FAERS database, and the adverse events signal intensity was determined using the reporting odds ratio, proportional reporting ratio, information component, and empirical Bayes geometric mean methods. Time-to-onset and univariate logistic regression analysis were performed to describe the characteristics and risk factors of oxaliplatin-associated neurological adverse events.

Results

A total of 4,471 cases of oxaliplatin-associated neurological adverse events were identified, with 318 neurological adverse events being documented, among which 87 adverse events satisfied the thresholds of four methodologies. The median time-to-onset of oxaliplatin-associated neurological adverse events was 2 days (interquartile range 0-36 days). Among the factors significantly influencing oxaliplatin-related neurological adverse events, male sex and combination medication decreased the risk of neurological adverse events, while higher cumulative dose increased the risk.

Conclusion

The real-world neurotoxicity spectrum of oxaliplatin and its characteristics and influencing factors were obtained through data mining of FAERS, providing valuable insights for healthcare professionals to effectively manage the risk of neurological adverse events associated with oxaliplatin in clinical practice.

Effect of tangeretin on cisplatin-induced oxido-inflammatory brain damage in rats

Cisplatin (CIS) is a platinum-derived chemotherapeutic agent commonly utilized in the treatment of various malignant tumours. However, anticancer doses of the drug cause serious damage to the brain. This study aimed to determine the potential protective effects of tangeretin, which has antioxidant and anti-inflammatory properties, in cisplatin-induced neurotoxicity on BALB/c mice brains. Male BALB/c mice were randomized and separated into four groups. Tangeretin was given for 10 days by gavage. CIS was injected as a single dose of 10 mg/kg intraperitoneally (ip) on the 10th day. Brain tissues, malondialdehyde (MDA), total glutathione (tGSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and nitric oxide (NO) levels were measured to determine oxidative damage and myeloperoxidase, tumour necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), IL-6 and IL-10 were measured to determine inflammatory activity. In addition, 8-OHdG and caspase-3 were analysed by immunofluorescence methods. While CIS administration remarkably elevated reactive oxygen species, MDA, and NO levels in brain tissue compared to the control, tGSH, GPx, SOD and CAT levels were significantly decreased. Also, it has been detected that TNF-α, IL-1β and IL-6 obtained in CIS-treated groups increased as well as IL-10 decreased, thereby elevating the inflammatory response. In addition, 8-OHdG and caspase-3 immunoreactivity in neurons increased with CIS administration. Treatment with tangeretin ameliorated the deterioration in oxidant/antioxidant status, overpowered neuroinflammation and ameliorated neurotoxicity-induced apoptosis. This study shows that tangeretin has beneficial effects on CIS-induced neurodegeneration. Possible mechanisms underlying these beneficial effects include the antioxidant and anti-inflammatory properties of tangeretin.

Cisplatin in the era of PARP inhibitors and immunotherapy

Platinum compounds such as cisplatin, carboplatin and oxaliplatin are widely used in chemotherapy. Cisplatin induces cytotoxic DNA damage that blocks DNA replication and gene transcription, leading to arrest of cell proliferation. Although platinum therapy alone is effective against many tumors, cancer cells can adapt to the treatment and gain resistance. The mechanisms for cisplatin resistance are complex, including low DNA damage formation, high DNA repair capacity, changes in apoptosis signaling pathways, rewired cell metabolisms, and others. Drug resistance compromises the clinical efficacy and calls for new strategies by combining cisplatin with other therapies. Exciting progress in cancer treatment, particularly development of poly (ADP-ribose) polymerase (PARP) inhibitors and immune checkpoint inhibitors, opened a new chapter to combine cisplatin with these new cancer therapies. In this Review, we discuss how platinum synergizes with PARP inhibitors and immunotherapy to bring new hope to cancer patients.

2D and 3D anticancer properties of C2-functionalised glucosamine-Pt (IV) prodrugs based on cisplatin scaffold

A series of C2-functionalied Pt (IV) glycoconjugates based on glucosamine have been synthesised, characterised and tested as anticancer agents on a series of different 2D and 3D cancer cell lines. The carbohydrate will act as a targeted delivery system to improve the selectivity, exploiting the Warburg Effect and the GLUTs receptors that are overexpressed in most of the cancer cells. The hydroxyl at C2 of the carbohydrates does not participate in hydrogen bonding with the GLUTs receptors, making C2 an attractive position for drug conjugation as seen in literature. In this study, we use the amino functionality at the C2 position in glucosamine and Copper-catalysed Azide-Alkyne Cycloaddition "click" (CuAAC) reaction to connect the prodrug Pt (IV) scaffold to the carbohydrate. We have investigated complexes with different linker lengths, as well as acetyl protected and free derivatives. To the best of our knowledge, this study represents the first series of Pt (IV) glucosamine-conjugates functionalised at C2.

Chemotherapeutic drug elemene induces pain and anxiety-like behaviors by activating GABAergic neurons in the lateral septum of mice

Most chemotherapeutic drugs are potent and have a very narrow range of dose safety and efficacy, most of which can cause many side effects. Chemotherapy-induced peripheral neuropathy (CIPN) is the most common and serious side effect of chemotherapy for cancer treatment. However, its mechanism of action is yet to be fully elucidated. In the present study, we found that the treatment of the chemotherapy drug elemene induced hyperalgesia accompanied by anxiety-like emotions in mice based on several pain behavioral assays, such as mechanical allodynia and thermal hyperalgesia tests. Second, immunostaining for c-fos (a marker of activated neurons) further showed that elemene treatment activated several brain regions, including the lateral septum (LS), cingulate cortex (ACC), paraventricular nucleus of the thalamus (PVT), and dorsomedial hypothalamic nucleus (DMH), most notably in the GABAergic neurons of the lateral septum (LS). Finally, we found that both chemogenetic inhibition and apoptosis of LS neurons significantly reduced pain- and anxiety-like behaviors in mice treated with elemene. Taken together, these findings suggest that LS is involved in the regulation of elemene-induced chemotherapy pain and anxiety-like behaviors, providing a new target for the treatment of chemotherapy pain induced by elemene.

Biomarkers of fatigue in oncology: A systematic review

Cancer-related fatigue (CRF) is a distressing side effect of cancer and treatment, affecting both patients during active treatment and survivors, negatively impacting quality of life. While its exact cause remains uncertain, various mechanisms such as immune dysfunction, HPA-axis dysfunction, and treatment toxicity are proposed. Inflammatory biomarkers of CRF have been explored in previous research, but non-inflammatory markers have not been comprehensively studied. This systematic review analysed 33 studies to identify non-inflammatory peripheral blood biomarkers associated with CRF. Promising markers included Hb, blood coagulation factors, BDNF, tryptophan, GAA, mtDNA, platinum, CA125, and cystatin-C. Inconsistent findings were observed for other markers like VEGF, leptin, and stress hormones. Most studies focused on adults. Research in pediatrics is limited. This review showed partial evidence for the inflammaging hypothesis (neurotoxicity due to neuro-inflammation) laying at the basis of CRF. Further research, especially in pediatrics, is needed to confirm this hypothesis and guide future biomarker studies.

The Effects of an App-Based Physical Activity Program on Colorectal Cancer Patients Undergoing Chemotherapy: A Randomized Controlled Trial

BACKGROUND

Colorectal cancer is one of the most common malignancies worldwide. Oxaliplatin, which is used as adjuvant chemotherapy, affects quality of life by causing oxaliplatin-induced peripheral neuropathy in colorectal cancer patients.

OBJECTIVES

This study examined the effects of an application (app)-based physical activity program for alleviating peripheral neuropathy symptoms in colorectal cancer patients undergoing chemotherapy.

METHODS

This was a randomized controlled study that included 34 patients undergoing chemotherapy after being diagnosed with colorectal cancer. Outcomes were compared between patients who participated in a 6-week app-based physical activity program (experimental group; n = 17) and who received standard booklet education (control group; n = 17). Data were collected using questionnaires, and exercise time was recorded to evaluate intervention adherence.

RESULTS

Significant differences were observed between the groups in peripheral neuropathy symptoms (F = 8.93, P = .002), interference with activities (Z = -2.55, P = .011), and quality of life (F = 7.65, P = .003). The experimental group showed significantly higher average exercise times at 1 to 4 weeks (Z = -2.10, P = .026), 5 to 6 weeks (Z = -4.02, P < .001), and 1 to 6 weeks (Z = -3.40, P = .001) than the control group.

CONCLUSIONS

The app-based physical activity program had a positive effect on participants' exercise adherence and reduced peripheral neuropathy symptoms. Thus, we propose the adoption of a mobile health app that can be used at any time or place as an intervention for preventing or alleviating adverse effects during the treatment of cancer patients.

IMPLICATIONS FOR PRACTICE

An app-based physical activity program using the mobile health app can be used as a nursing intervention to manage symptoms and increase the health behavior adherence in cancer patients.

Blinding Optic Neuropathy Associated With Carboplatin Therapy: A Case Report and Literature Review

Various forms of cancer and chemotherapeutics are associated with optic neuropathy. Cisplatin is a platinum analogue chemotherapeutic commonly associated with ocular toxicity among many other serious adverse effects. Carboplatin is a more chemically stable platinum analogue that is generally better tolerated with a comparatively favorable side effect profile. There are very few reports of carboplatin precipitating optic neuropathy. This case report describes a rare occurrence of carboplatin-induced blinding optic neuropathy. We treated a patient receiving carboplatin for neuroendocrine bladder cancer who developed rapidly progressive bilateral optic neuropathy over the course of three days. Upon evaluation at our clinic, his visual acuity had declined to light perception only and 20/60 in his left and right eye, respectively. Carboplatin therapy was immediately held and steroids were initiated. Despite the intervention, the patient's visual deficits have not improved at the one-year follow-up. Although the mechanism by which carboplatin causes ocular toxicity remains speculative, arterial ischemia appears to be the likely mechanism given the irreversible nature of visual decline. As demonstrated by our patient's course, irreversible vision loss despite high-dose steroid intervention necessitates expeditious recognition and management of this rare adverse effect. ​​​​​.

An In Vitro Assessment Method for Chemotherapy-Induced Peripheral Neurotoxicity Caused by Anti-Cancer Drugs Based on Electrical Measurement of Impedance Value and Spontaneous Activity

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major adverse event of anti-cancer drugs, which still lack standardized measurement and treatment methods. In the present study, we attempted to evaluate neuronal dysfunctions in cultured rodent primary peripheral neurons using a microelectrode array system. After exposure to typical anti-cancer drugs (i.e., paclitaxel, vincristine, oxaliplatin, and bortezomib), we successfully detected neurotoxicity in dorsal root ganglia neurons by measuring electrical activities, including impedance value and spontaneous activity. The impedance value decreased significantly for all compounds, even at low concentrations, which indicated cell loss and/or neurite degeneration. The spontaneous activity was also suppressed after exposure, which suggested neurotoxicity again. However, an acute response was observed for paclitaxel and bortezomib before toxicity, which showed different mechanisms based on compounds. Therefore, MEA measurement of impedance value could provide a simple assessment method for CIPN, combined with neuronal morphological changes.

The association of clinical and patient factors with chemotherapy-induced peripheral neuropathy (CIPN) in colorectal cancer: secondary analysis of the SCOT trial

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of oxaliplatin. CIPN can impair long-term quality of life and limit the dose of chemotherapy. We investigated the association of CIPN over time with age, sex, body mass index, baseline neuropathy, and chemotherapy regimen in people treated with adjuvant oxaliplatin-containing chemotherapy for colorectal cancer.

PATIENTS AND METHODS

We carried out secondary analysis of data from the SCOT randomised controlled trial. SCOT compared 3 months to 6 months of oxaliplatin-containing adjuvant chemotherapy in 6088 people with colorectal cancer recruited between March 2008 and November 2013. Two different chemotherapy regimens were used: capecitabine with oxaliplatin (CAPOX) or fluorouracil with oxaliplatin (FOLFOX). CIPN was recorded with the Functional Assessment of Cancer Therapy/Gynaecologic Oncology Group-Neurotoxicity 4 tool in 2871 participants from baseline (randomisation) for up to 8 years. Longitudinal trends in CIPN [averages with 95% confidence intervals (CIs)] were plotted stratified by the investigated factors. Analysis of covariance (ANCOVA) was used to analyse the association of factors with CIPN adjusting for the SCOT randomisation arm and oxaliplatin dose. P < 0.01 was adopted as cut-off for statistical significance to account for multiple testing.

RESULTS

Patients receiving CAPOX had lower CIPN scores than those receiving FOLFOX. Chemotherapy regimen was associated with CIPN from 6 months (P < 0.001) to 2 years (P = 0.001). The adjusted ANCOVA coefficient for CAPOX at 6 months was -1.6 (95% CIs -2.2 to -0.9) and at 2 years it was -1.6 (95% CIs -2.5 to -0.7). People with baseline neuropathy scores ≥1 experienced higher CIPN than people with baseline neuropathy scores of 0 (P < 0.01 for all timepoints apart from 18 months). Age, sex, and body mass index did not link with CIPN.

CONCLUSIONS

A neuropathy assessment before treatment with oxaliplatin can help identify people with an increased risk of CIPN. More research is needed to understand the CIPN-inducing effect of different chemotherapy regimens.

Abnormal brain glucose metabolism patterns in patients with advanced non-small-cell lung cancer after chemotherapy：A retrospective PET study

PURPOSE

This study was designed to investigate the acute or chronic post-chemotherapy effect and different chemotherapy cycles effect on brain glucose metabolism.

METHODS

A total of seventy-three patients who received chemotherapy after being diagnosed with advanced non-small-cell lung cancer (NSCLC) and underwent 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan at Nuclear Medicine Department of the Fifth Hospital of Sun Yat-sen University between September 2017 and August 2022 were included. Seventy-two healthy control patients who underwent whole-body 18F-FDG PET/CT scans at our department, without any evidence of malignancy and confirmed by follow-up visits, were included. Advanced NSCLC patients were classified into six arms: short-to-long course (chemotherapy cycles under 4, between 5 and 8 and more than 8) in acute chemotherapy effect (AC) group (scanned 18F-FDG PET/CT within 6 months post-chemotherapy) or chronic chemotherapy effect (CC) group (the interval between scanning and the last chemotherapy session more than six months). Statistical Parametric Mapping (SPM) analysis between patients' groups and healthy controls' brain 18F-FDG PET was performed (uncorrected p ˂ 0.001 with cluster size above 20 contiguous voxels).

RESULTS

There were no significant differences between patients' groups and healthy controls in age, gender and body mass index (BMI). SPM PET analyses revealed anomalous brain metabolic activity in different groups (p ˂ 0.001). Short-course + AC group exhibited hypermetabolism in the cerebellum and widespread hypometabolism in bilateral frontal lobe predominantly. Only hypometabolic brain regions were observed in middle-course + AC patients. Long-course + AC group displayed a greater number of abnormalities. Notably, these metabolic abnormalities tended to decrease in CC groups versus AC groups across all courses.

CONCLUSION

Our study revealed that patients with advanced NSCLC who underwent chemotherapy exhibited persistent abnormal brain metabolism patterns during continuous chemotherapy and these abnormalities tended to recover after completion of chemotherapy over time, but without correlation to an increasing number of chemotherapy cycles. 18F-FDG PET/CT may serve as a possible modality for evaluating brain function and guiding appropriate treatment timing.

Randomized controlled trial on the effect of 1-hour infusion of vincristine versus push injection on neuropathy in children with cancer (final analysis)

INTRODUCTION

Vincristine is an integral component of treatment for children with cancer. Its main dose-limiting side effect is vincristine-induced peripheral neuropathy (VIPN). The VINCA trial was a randomized controlled trial that explored the effect of 1-hour infusion compared with push injection of vincristine on the development of VIPN in children with cancer. The short-term outcomes (median follow-up 9 months) showed that there was no difference in VIPN between the randomization groups. However, 1-hour infusion was less toxic in children who also received azoles. We now report the results of the final analyses (median follow-up 20 months), which includes treatment outcome as a secondary objective (follow-up 3 years).

METHODS

VIPN was measured 1-7 times per participant using the Common Terminology Criteria for Adverse Events (CTCAE) and the pediatric-modified total neuropathy score. Poisson mixed model and logistic generalized estimating equation analysis for repeated measures were performed.

RESULTS

Forty-five participants per randomization group were included. There was no significant effect of 1-hour infusion compared with push injection on VIPN. In participants receiving concurrent azoles, the total CTCAE score was significantly lower in the one-hour group (rate ratio 0.52, 95% confidence interval 0.33-0.80, p = 0.003). Four patients in the one-hour group and one patient in the push group relapsed. Two patients in the one-hour group died.

CONCLUSION

1-hour infusion of vincristine is not protective against VIPN. However, in patients receiving concurrent azoles, 1-hour infusion may be less toxic. The difference in treatment outcome is most likely the result of differences in risk profile.

Neuroprotective effect of lansoprazole against cisplatin-induced brain toxicity: Role of Nrf2/ARE and Akt/P53 signaling pathways

Cisplatin is a chemotherapeutic agent usually used in treating different patterns of malignancies. One of the significant apparent complications of cisplatin chemotherapy is brain toxicity. The present study was conducted to evaluate the protective effects of lansoprazole on cisplatin-induced cortical intoxication. Thirty-two rats were allocated into four groups (8 rats/group); group I: received only a vehicle for 10 days, group II: lansoprazole was administered (50 mg/kg) via oral gavage for 10 days, group III: On 5th day of the experiment, rats were given cisplatin (10 mg/kg) i.p. once to induce cortical injury. Group IV: rats were given lansoprazole for 5 days before cisplatin and 5 days afterward. Lansoprazole administration significantly improved cisplatin-induced behavioral changes, as evidenced by decreasing the immobility time in forced swimming and open field tests. Besides, lansoprazole improved cortical histological changes, restored cortical redox balance, enhanced Nrf2/ARE expression, cisplatin-induced neuronal apoptosis, and dampened cisplatin inflammation. In addition, lansoprazole modulated cortical Akt/p53 signal. The present work was the first to show that lansoprazole co-administration reduced cortical toxicity in cisplatin-treated rats via multiple signaling pathways. The current findings provided crucial information for developing novel protective strategies to reduce cisplatin cortical toxicity.

Emerging platinum(IV) prodrug nanotherapeutics: A new epoch for platinum-based cancer therapy

Owing to the unique DNA damaging cytotoxicity, platinum (Pt)-based chemotherapy has long been the first-line choice for clinical oncology. Unfortunately, Pt drugs are restricted by the severe dose-dependent toxicity and drug resistance. Correspondingly, Pt(IV) prodrugs are developed with the aim to improve the antitumor performance of Pt drugs. However, as "free" molecules, Pt(IV) prodrugs are still subject to unsatisfactory in vivo destiny and antitumor efficacy. Recently, Pt(IV) prodrug nanotherapeutics, inheriting both the merits of Pt(IV) prodrugs and nanotherapeutics, have emerged and demonstrated the promise to address the underexploited dilemma of Pt-based cancer therapy. Herein, we summarize the latest fronts of emerging Pt(IV) prodrug nanotherapeutics. First, the basic outlines of Pt(IV) prodrug nanotherapeutics are overviewed. Afterwards, how versatile Pt(IV) prodrug nanotherapeutics overcome the multiple biological barriers of antitumor drug delivery is introduced in detail. Moreover, advanced combination therapies based on multimodal Pt(IV) prodrug nanotherapeutics are discussed with special emphasis on the synergistic mechanisms. Finally, prospects and challenges of Pt(IV) prodrug nanotherapeutics for future clinical translation are spotlighted.

Satellite glial cell-secreted exosomes after in-vitro oxaliplatin treatment presents a pro-nociceptive effect for dorsal root ganglion neurons and induce mechanical hypersensitivity in naïve mice

BACKGROUND

The pathophysiological mechanism underlying chemotherapy-induced neuropathic pain (CINP) remains unclear. Sensory neuronal hypersensitivity in the dorsal root ganglion (DRG) is essential for the onset and maintenance of chronic pain. Satellite glial cells (SGCs) in the DRG potentially affect the function of sensory neurons, possibly by mediating extracellular or paracrine signaling. Exosomes play an essential role in cell-cell communication. However, the role of SGC-secreted exosomes in glia-neuron communication and CINP remains unclear.

METHODS

SGCs and sensory neurons were cultured from the DRG of mice. The SGCs were treated with 4 μM oxaliplatin for 24 h. Glial fibrillary acid protein (GFAP) and connexin-43 (Cx-43) expressions in the SGCs were examined with immunocytochemistry (ICC). Enzyme-linked immunosorbent assay (ELISA) detected cytokine release in the SGCs after oxaliplatin treatment. Subsequently, SGC-secreted exosomes were collected using ultracentrifugation and identified by nanoparticle tracking analysis, transmission electron microscopy, and western blotting. Subsequently, DRG neurons were incubated with SGC-secreted exosomes for 24 h. The percentage of reactive oxygen species (ROS)-positive neurons was detected using flow cytometry, and acid-sensing ion channel 3 (ASIC3) and transient receptor potential vanilloid 1 (TRPV1) expression were examined by western blotting. SGC-secreted exosomes were intrathecally injected into naïve mice. The mechanical withdrawal threshold was assessed 24, 48, and 72 h following the injection. TRPV1 expression in the DRG was examined 72 h after intrathecal injection. Furthermore, differentially expressed (DE) miRNAs within the SGC-secreted exosomes were detected using RNA sequencing and bioinformatics analysis. Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway analyses were performed to predict the function of the target genes of DE miRNAs. Finally, the DE miRNAs with pain regulation potential were identified in silico.

RESULTS

After in-vitro oxaliplatin treatment, ICC showed an increase in the immunoreactivity of GFAP and Cx-43 in the SGCs. ELISA results suggested an increased release of tumor necrosis factor-α and interleukin (IL)-1β, but a decreased release of IL-10. Oxaliplatin treatment increased the secretion of exosomes in the SGCs from 4.34 to 5.99 × 1011 (particles/ml). The exosome-specific markers CD9 and TSG101 were positive, whereas calnexin was negative for the obtained exosomes. Additionally, the SGC-secreted exosomes were endocytosed by DRG neurons after co-incubation. Moreover, after incubation with conditioned SGC-secreted exosomes (after 4 μM oxaliplatin treatment), the percentage of ROS-positive DRG neurons increased and ASIC3 and TRPV1 expressions were upregulated. After the intrathecal injection of the conditioned SGC-secreted exosomes, the mice presented with mechanical hypersensitivity and TRPV1 expression upregulation in the DRG. Notably, 25 and 120 significantly upregulated and downregulated miRNAs, respectively, were identified in the conditioned SGC-secreted exosomes. When predicting the function of target genes of DE miRNAs, certain GO terms, such as synapse organization, neurogenesis regulation, histone modification, and pain-related KEGG or Reactome pathways, including vascular endothelial growth factor A-vascular endothelial growth factor receptor 2, mammalian target of rapamycin, and mitogen-activated protein kinase signaling pathways, related to nervous system function were predicted. Finally, 27 pain regulation-related miRNAs, including miR-324-3p, miR-181a-5p, and miR-122-5p, were identified in silico.

CONCLUSION

Our study demonstrates that SGC-secreted exosomes after in-vitro oxaliplatin treatment present a pro-nociceptive effect for DRG neurons and induce mechanical hypersensitivity in naïve mice, possibly via the contained miRNA cargo. Identifying the candidate miRNAs and verifying their functions in vivo are required to elucidate the exosomes mediating 'glia-neuron' communication under CINP condition.

Modulating Hyperpolarization-Activated Cation Currents through Small Molecule Perturbations: Magnitude and Gating Control

The hyperpolarization-activated cation current (Ih) exhibits a slowly activating time course of the current (Ih) when the cell membrane is hyperpolarized for an extended duration. It is involved in generating electrical activity in various excitable cells. Numerous structurally distinct compounds or herbal drugs have the potential to impact both the magnitude and gating kinetics of this current. Brivaracetam, a chemical analog of levetiracetam known to be a ligand for synaptic vesicle protein 2A, could directly suppress the Ih magnitude. Carisbamate, an anticonvulsant agent, not only inhibited the Ih amplitude but also reduced the strength of voltage-dependent hysteresis (Hys(V)) associated with Ih. Cilobradine, similar to ivabradine, inhibited the amplitude of Ih; however, it also suppressed the amplitude of delayed-rectifier K+ currents. Dexmedetomidine, an agonist of α2-adrenergic receptor, exerted a depressant action on Ih in a concentration-dependent fashion. Suppression of Ih amplitude was observed when GAL-021, a breathing control modulator, was present at a concentration exceeding 30 μM. Lutein, one of the few xanthophyll carotenoids, was able to suppress the Ih amplitude as well as to depress Hys(V)'s strength of Ih. Pirfenidone, a pyridine derivative known to be an anti-fibrotic agent, depressed the Ih magnitude in a concentration- and voltage-dependent fashion. Tramadol, a synthetic centrally active analgesic, was shown to reduce the Ih magnitude, independent of its interaction with opioid receptors. Various herbal drugs, including ent-kaurane-type diterpenoids from Croton tonkinensis, Ganoderma triterpenoids, honokiol, and pterostilbene, demonstrated efficacy in reducing the magnitude of Ih. Conversely, oxaliplatin, a platinum-based chemotherapeutic compound, was observed to effectively increase the Ih amplitude. Collectively, the regulatory effects of these compounds or herbal drugs on cellular function can be partly attributed to their perturbations on Ih.

Scientific and Regulatory Policy Committee Technical Review: Biology and Pathology of Ganglia in Animal Species Used for Nonclinical Safety Testing

Dorsal root ganglia (DRG), trigeminal ganglia (TG), other sensory ganglia, and autonomic ganglia may be injured by some test article classes, including anti-neoplastic chemotherapeutics, adeno-associated virus-based gene therapies, antisense oligonucleotides, nerve growth factor inhibitors, and aminoglycoside antibiotics. This article reviews ganglion anatomy, cytology, and pathology (emphasizing sensory ganglia) among common nonclinical species used in assessing product safety for such test articles (TAs). Principal histopathologic findings associated with sensory ganglion injury include neuron degeneration, necrosis, and/or loss; increased satellite glial cell and/or Schwann cell numbers; and leukocyte infiltration and/or inflammation. Secondary nerve fiber degeneration and/or glial reactions may occur in nerves, dorsal spinal nerve roots, spinal cord (dorsal and occasionally lateral funiculi), and sometimes the brainstem. Ganglion findings related to TA administration may result from TA exposure and/or trauma related to direct TA delivery into the central nervous system or ganglia. In some cases, TA-related effects may need to be differentiated from a spectrum of artifactual and/or spontaneous background changes.

Transcriptomics and systems network-based molecular mechanism of herbal formula Huosu-Yangwei inhibited gastric cancer in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

The efficacy of the herbal formula Huosu-Yangwei (HSYW) in the treatment of advanced gastric cancer and chronic atrophic gastritis with precancerous lesions has been reported in clinical trials. However, the molecular mechanisms underlying its inhibition of gastric tumor are not well-understood.

AIM OF THE STUDY

Combined with transcriptomics and systems network-based molecular mechanism to explore the potential circRNA-miRNA-mRNA network of HSYW in the treatment of gastric cancer.

MATERIALS AND METHODS

Animal experiments were conducted to investigate the effect of HSYW on tumor growth in vivo. RNA sequencing (RNA-seq) was implemented to identify the differentially expressed (DE) genes. Predictive miRNA targets and mRNA were used to construct circRNA-miRNA-mRNA networks and protein-protein interaction (PPI) networks. Quantitative real-time PCR (qRT-PCR) was utilized to verify the accuracy of the proposed circRNA-miRNA-mRNA networks. Additionally, the differentially expressed target proteins between gastric cancer (GC) and normal patients were assessed using data from the TCGA (The Cancer Genome Atlas) and HPA (The Human Protein Atlas) databases.

RESULTS

We demonstrate HSYW significantly inhibits tumor growth of N87 cell-bearing Balb/c mice. Transcriptomic analysis revealed the existence of 119 differentially expressed (DE) circRNAs and 200 DE mRNAs between HSYW-treated and model mice. By associating predicted circRNA-miRNA pairs and miRNA-mRNA pairs, we constructed a circRNA-miRNA-mRNA (CMM) network. Furthermore, a protein-protein interaction (PPI) network was developed using the differential expressed mRNAs. Consequently, the reconstructed core CMM network and qRT-PCR validation indicated that 4 circRNAs, 5 miRNAs and 6 mRNAs could potentially serve as biomarkers to assess the therapeutic effects of HSYW-treated N87-bearing Balb/c mice. The TCGA and HPA databases also demonstrated that mRNA KLF15 and PREX1 had substantial differences between gastric cancer (GC) and healthy controls.

CONCLUSIONS

By combining the experimental and bioinformatics analysis, this study confirms that the circRNA_00240/hsa-miR-642a-5p/KLF15 and circRNA_07980/hsa-miR-766-3p/PREX1 pathways play critical roles in HSYW-treated gastric cancer.

Scientific and Regulatory Policy Committee Points to Consider: Sampling, Processing, Evaluation, Interpretation, and Reporting of Test Article-Related Ganglion Pathology for Nonclinical Toxicity Studies

Certain biopharmaceutical products consistently affect dorsal root ganglia, trigeminal ganglia, and/or autonomic ganglia. Product classes targeting ganglia include antineoplastic chemotherapeutics, adeno-associated virus-based gene therapies, antisense oligonucleotides, and anti-nerve growth factor agents. This article outlines "points to consider" for sample collection, processing, evaluation, interpretation, and reporting of ganglion findings; these points are consistent with published best practices for peripheral nervous system evaluation in nonclinical toxicity studies. Ganglion findings often occur as a combination of neuronal injury (e.g., degeneration, necrosis, and/or loss) and/or glial effects (e.g., increased satellite glial cell cellularity) with leukocyte accumulation (e.g., mononuclear cell infiltration or inflammation). Nerve fiber degeneration and/or glial reactions may be seen in nerves, dorsal spinal nerve roots, spinal cord, and occasionally brainstem. Interpretation of test article (TA)-associated effects may be confounded by incidental background changes or experimental procedure-related changes and limited historical control data. Reports should describe findings at these sites, any TA relationship, and the criteria used for assigning severity grades. Contextualizing adversity of ganglia findings can require a weight-of-evidence approach because morphologic changes of variable severity occur in ganglia but often are not accompanied by observable overt in-life functional alterations detectable by conventional behavioral and neurological testing techniques.

Prevention and Treatment of Chemotherapy-Induced Alopecia: What Is Available and What Is Coming?

Millions of new cancer patients receive chemotherapy each year. In addition to killing cancer cells, chemotherapy is likely to damage rapidly proliferating healthy cells, including the hair follicle keratinocytes. Chemotherapy causes substantial thinning or loss of hair, termed chemotherapy-induced alopecia (CIA), in approximately 65% of patients. CIA is often ranked as one of the most distressing adverse effects of chemotherapy, but interventional options have been limited. To date, only scalp cooling has been cleared by the US Food and Drug Administration (FDA) to prevent CIA. However, several factors, including the high costs not always covered by insurance, preclude its broader use. Here we review the current options for CIA prevention and treatment and discuss new approaches being tested. CIA interventions include scalp cooling systems (both non-portable and portable) and topical agents to prevent hair loss, versus topical and oral minoxidil, photobiomodulation therapy (PBMT), and platelet-rich plasma (PRP) injections, among others, to stimulate hair regrowth after hair loss. Evidence-based studies are needed to develop and validate methods to prevent hair loss and/or accelerate hair regrowth in cancer patients receiving chemotherapy, which could significantly improve cancer patients’ quality of life and may help improve compliance and consequently the outcome of cancer treatment.

Ozone in Chemotherapy-Induced Peripheral Neuropathy—Current State of Art, Possibilities, and Perspectives

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most detrimental toxicity to a patient’s quality of life. Pathophysiological mechanisms involved in CIPN pathogenesis are complex, multifactorial, and only partially examined. They are suspected to be associated with oxidative stress (OS), mitochondrial dysfunction, ROS-induced apoptosis, myelin sheath and DNA damage, and immunological and inflammatory processes. Unfortunately, medications commonly used for the management of other neuropathic pain syndromes, including gabapentinoids, opioids, and tricyclic antidepressants (such as desipramine and nortriptyline), do not bring satisfactory results in CIPN. The aim of this review is to evaluate the existing literature on the potential use of medical ozone as a treatment for CIPN. This paper would explore the potential therapeutic benefits of medical ozone. The review would evaluate the existing literature on the use of medical ozone in other contexts, as well as its potential application in treating CIPN. The review would also suggest possible research methods, such as randomized controlled trials, to evaluate the efficacy of medical ozone as a treatment for CIPN. Medical ozone has been used to disinfect and treat diseases for over 150 years. The effectiveness of ozone in treating infections, wounds, and a variety of diseases has been well documented. Ozone therapy is also documented to inhibit the growth of human cancer cells and has antioxidative and anti-inflammatory effects. Due to its ability to modulate oxidative stress, inflammation, and ischemia/hypoxia, ozone may have a potentially valuable effect on CIPN.