Recent Developments of Novel Pharmacologic Therapeutics for Prevention of Chemotherapy-Induced Peripheral Neuropathy

Efficacy and safety of traditional plant-based medicines for preventing chronic oxaliplatin-induced peripheral neurotoxicity in patients with colorectal cancer: A systematic review and meta-analysis with core herb contribution

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional plant-based medicines (TMs) have been widely used to prevent chronic oxaliplatin-induced peripheral neurotoxicity (OIPN). However, the prevention and safety of TMs for chronic OIPN remain ambiguous. Furthermore, diverse TM prescriptions and complicated components limit in-depth research on the mechanisms of TMs.

AIM OF THIS STUDY

To determine core TMs and potential pharmacological pathways on the basis of a thorough investigation into the preventive benefits and safety of oral TMs for chronic OIPN in colorectal cancer (CRC).

METHODS

A search of the PubMed, Cochrane, Embase, CNKI, VIP, and Wanfang databases for RCTs reporting on TMs for chronic OIPN was conducted through December 1, 2022. Subgroup analysis, sensitivity analysis and meta-regression were applied to assess the impacts of influencing variables. The assessment of Risk of Bias was relied on Cochrane Risk of Bias tool. The funnel plot, Egger's test, and the Trim and Fill method were applied to identify potential publication bias. Trial sequential analyses (TSA) were carried out by the TSA tool to increase the robustness. The assessment of the quality of evidence was according to the GRADE system. System pharmacology analysis was employed to screen core herbal combinations to elucidate possible mechanisms for preventing chronic OIPN in CRC.

RESULTS

The pooled effect estimate with robustness increased by TSA analysis demonstrated that oral TMs appeared to significantly decrease the incidence of chronic OIPN (RR = 0.66, 95% CI (0.56, 0.78); P＜0.00001), leukocytopenia (RR = 0.65, 95% CI (0.54,0.79); P＜0.00001), and nausea and vomiting (RR = 0.72, 95% CI (0.61,0.84); P＜0.0001) as well as improve the Objective Response Rate (ORR) (RR = 1.31, 95% CI (1.09,1.56); P = 0.003). The incidence of severe chronic OIPN was revealed a significant reduction, particularly when chemotherapy was administered for periods of time shorter than six months (RR = 0.33, 95% CI (0.15,0.71); P = 0.005; actuation duration＜3 months; RR = 0.33, 95% CI (0.17,0.62); P = 0.0007; actuation duration≥3 months, ＜6 months). The considerable heterogeneity among studies may be attributable to the severity of dysfunction categorized by grade and accumulated dosage. Using core TMs consisting of Astragalus membranaceus (Fisch.) Bunge, Atractylodes Macrocephala Koidz., Poria cocos (Schw.) Wolf, and Codonopsis pilosula (Franch.) Nannf. To regulate nuclear factor-kappa B against inflammation caused by activation of microglia might be an approach to preventing chronic OIPN.

CONCLUSIONS

TMs appear to be effective and safe in the prevention of chronic OIPN, especially severe chronic OIPN. Additionally, core TMs consisting of Astragalus membranaceus (Fisch.) Bunge, Atractylodes Macrocephala Koidz., Poria cocos (Schw.) Wolf, and Codonopsis pilosula (Franch.) Nannf were presumably responsible for reducing the incidence of chronic OIPN, and the mechanism may be related to relieving inflammation. However, quality-assured trials with long-term follow-up for exploring inflammatory factors and preliminary research on core TMs and pharmacological pathways are needed.

Paeoniflorin ameliorates oxaliplatin-induced peripheral neuropathy via inhibiting neuroinflammation through influence on gut microbiota

Oxaliplatin (OXA)-induced peripheral neuropathy (OIPN) is a severe side effect that greatly limits OXA clinical use and threatens patients' life and health. Paeoniflorin exhibits extensive anti-inflammatory and neuroprotective effects, but whether it can protect against OIPN and the underlying mechanisms remain unclear. This study aimed to investigate the effects of paeoniflorin on OIPN and probe into the underlying mechanisms. The OIPN model was established through oxaliplatin injection in rats. The ameliorative effects of paeoniflorin on OIPN was assessed by nociceptive hypersensitivities through pain behavioral methods. Neuroinflammation were examined by measuring the levels of inflammatory cytokines and immune cells infiltration. The signaling pathway of TLR4/MyD88/NF-κB was evaluated by Western blotting. Gut microbial changes were detected by 16S rDNA sequencing technology. In addition, antibiotics-induced microbiota eradication and fecal microbial transplantation (FMT) were applied for exploring the function of gut microbiota in the protective effects of paeoniflorin. The results revealed that paeoniflorin significantly alleviated mechanical and cold hypersensitivity, mitigated neuroinflammation and influenced gut microbial composition in OIPN rats. Fecal microbiota transplantation further verified that gut microbiota was required for paeoniflorin ameliorating OIPN and that the underlying mechanism involved downregulation of TLR4/MyD88/NF-κB signaling. Specifically, Akkermansia, Dubosiella and Corynebacterium might serve as crucial genera regulated by paeoniflorin in the treatment of OIPN. In summary, our investigations delineate paeoniflorin's ameliorative effects on OIPN by alleviating neuroinflammation through regulations of gut microbiota. This suggests that paeoniflorin may serve as a new potential strategy for treatment of OIPN in clinical practice.

Bortezomib-induced peripheral neuropathy: Clinical features, molecular basis, and therapeutic approach

Bortezomib is the first-line standard and most effective chemotherapeutic for multiple myeloma; however, bortezomib-induced peripheral neuropathy (BIPN) severely affects the chemotherapy regimen and has long-term impact on patients under maintenance therapy. The pathogenesis of BIPN is poorly understood, and basic research and development of BIPN management drugs are in early stages. Besides chemotherapy dose reduction and regimen modification, no recommended prevention and treatment approaches are available for BIPN apart from the International Myeloma Working Group guidelines for peripheral neuropathy in myeloma. An in-depth exploration of the pathogenesis of BIPN, development of additional therapeutic approaches, and identification of risk factors are needed. Optimizing effective and standardized BIPN treatment plans and providing more decision-making evidence for clinical diagnosis and treatment of BIPN are necessary. This article reviews the recent advances in BIPN research; provides an overview of clinical features, underlying molecular mechanisms, and therapeutic approaches; and highlights areas for future studies.

Label-Free Visualization and Morphological Profiling of Neuronal Differentiation and Axonal Degeneration through Quantitative Phase Imaging

Understanding the intricate processes of neuronal growth, degeneration, and neurotoxicity is paramount for unraveling nervous system function and holds significant promise in improving patient outcomes, especially in the context of chemotherapy-induced peripheral neuropathy (CIPN). These processes are influenced by a broad range of entwined events facilitated by chemical, electrical, and mechanical signals. The progress of each process is inherently linked to phenotypic changes in cells. Currently, the primary means of demonstrating morphological changes rely on measurements of neurite outgrowth and axon length. However, conventional techniques for monitoring these processes often require extensive preparation to enable manual or semi-automated measurements. Here, a label-free and non-invasive approach is employed for monitoring neuronal differentiation and degeneration using quantitative phase imaging (QPI). Operating on unlabeled specimens and offering little to no phototoxicity and photobleaching, QPI delivers quantitative maps of optical path length delays that provide an objective measure of cellular morphology and dynamics. This approach enables the visualization and quantification of axon length and other physical properties of dorsal root ganglion (DRG) neuronal cells, allowing greater understanding of neuronal responses to stimuli simulating CIPN conditions. This research paves new avenues for the development of more effective strategies in the clinical management of neurotoxicity.

Membrane transporters in drug development and as determinants of precision medicine

The effect of membrane transporters on drug disposition, efficacy and safety is now well recognized. Since the initial publication from the International Transporter Consortium, significant progress has been made in understanding the roles and functions of transporters, as well as in the development of tools and models to assess and predict transporter-mediated activity, toxicity and drug-drug interactions (DDIs). Notable advances include an increased understanding of the effects of intrinsic and extrinsic factors on transporter activity, the application of physiologically based pharmacokinetic modelling in predicting transporter-mediated drug disposition, the identification of endogenous biomarkers to assess transporter-mediated DDIs and the determination of the cryogenic electron microscopy structures of SLC and ABC transporters. This article provides an overview of these key developments, highlighting unanswered questions, regulatory considerations and future directions.

Protease-Activated Receptor 2 (PAR2) Expressed in Sensory Neurons Contributes to Signs of Pain and Neuropathy in Paclitaxel Treated Mice

Chemotherapy-induced peripheral neuropathy (CIPN) is a common, dose-limiting side effect of cancer therapy. Protease-activated receptor 2 (PAR2) is implicated in a variety of pathologies, including CIPN. In this study, we demonstrate the role of PAR2 expressed in sensory neurons in a paclitaxel (PTX)-induced model of CIPN in mice. PAR2 knockout/wildtype (WT) mice and mice with PAR2 ablated in sensory neurons were treated with PTX administered via intraperitoneal injection. In vivo behavioral studies were done in mice using von Frey filaments and the Mouse Grimace Scale. We then examined immunohistochemical staining of dorsal root ganglion (DRG) and hind paw skin samples from CIPN mice to measure satellite cell gliosis and intra-epidermal nerve fiber (IENF) density. The pharmacological reversal of CIPN pain was tested with the PAR2 antagonist C781. Mechanical allodynia caused by PTX treatment was alleviated in PAR2 knockout mice of both sexes. In the PAR2 sensory neuronal conditional knockout (cKO) mice, both mechanical allodynia and facial grimacing were attenuated in mice of both sexes. In the DRG of the PTX-treated PAR2 cKO mice, satellite glial cell activation was reduced compared to control mice. IENF density analysis of the skin showed that the PTX-treated control mice had a reduction in nerve fiber density while the PAR2 cKO mice had a comparable skin innervation as the vehicle-treated animals. Similar results were seen with satellite cell gliosis in the DRG, where gliosis induced by PTX was absent in PAR cKO mice. Finally, C781 was able to transiently reverse established PTX-evoked mechanical allodynia. PERSPECTIVE: Our work demonstrates that PAR2 expressed in sensory neurons plays a key role in PTX-induced mechanical allodynia, spontaneous pain, and signs of neuropathy, suggesting PAR2 as a possible therapeutic target in multiple aspects of PTX CIPN.

DRG Explant Model: Elucidating Mechanisms of Oxaliplatin-Induced Peripheral Neuropathy and Identifying Potential Therapeutic Targets

Oxaliplatin triggered chemotherapy induced peripheral neuropathy (CIPN) is a common and debilitating side effect of cancer treatment which limits the efficacy of chemotherapy and negatively impacts patients quality of life dramatically. For better understanding the mechanisms of CIPN and screen for potential therapeutic targets, it is critical to have reliable in vitro assays that effectively mirror the neuropathy in vivo . In this study, we established a dorsal root ganglia (DRG) explant model. This model displayed dose-dependent inhibition of neurite outgrowth in response to oxaliplatin, while oxalic acid exhibited no significant impact on the regrowth of DRG. The robustness of this assay was further demonstrated by the inhibition of OCT2 transporter, which facilitates oxaliplatin accumulation in neurons, fully restoring the neurite regrowth capacity. Using this model, we revealed that oxaliplatin triggered a substantial increase of oxidative stress in DRG. Notably, inhibition of TXNIP with verapamil significantly reduced oxidative stress level. Our results demonstrated the use of DRG explants as an efficient model to study the mechanisms of CIPN and screen for potential treatments.

Oxaliplatin-induced peripheral neurotoxicity in colorectal cancer patients: mechanisms, pharmacokinetics and strategies

Oxaliplatin-based chemotherapy is a standard treatment approach for colorectal cancer (CRC). However, oxaliplatin-induced peripheral neurotoxicity (OIPN) is a severe dose-limiting clinical problem that might lead to treatment interruption. This neuropathy may be reversible after treatment discontinuation. Its complicated mechanisms are related to DNA damage, dysfunction of voltage-gated ion channels, neuroinflammation, transporters, oxidative stress, and mitochondrial dysfunction, etc. Several strategies have been proposed to diminish OIPN without compromising the efficacy of adjuvant therapy, namely, combination with chemoprotectants (such as glutathione, Ca/Mg, ibudilast, duloxetine, etc.), chronomodulated infusion, dose reduction, reintroduction of oxaliplatin and topical administration [hepatic arterial infusion chemotherapy (HAIC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), and hyperthermic intraperitoneal chemotherapy (HIPEC)]. This article provides recent updates related to the potential mechanisms, therapeutic strategies in treatment of OIPN, and pharmacokinetics of several methods of oxaliplatin administration in clinical trials.

Mitigating long-term and delayed adverse events associated with cancer treatment: implications for survivorship

Despite the importance of chemotherapy-associated adverse events in oncology practice and the broad range of interventions available to mitigate them, limited systematic efforts have been made to identify, critically appraise and summarize the totality of evidence on the effectiveness of these interventions. Herein, we review the most common long-term (continued beyond treatment) and late or delayed (following treatment) adverse events associated with chemotherapy and other anticancer treatments that pose major threats in terms of survival, quality of life and continuation of optimal therapy. These adverse effects often emerge during and continue beyond the course of therapy or arise among survivors in the months and years following treatment. For each of these adverse effects, we discuss and critically evaluate their underlying biological mechanisms, the most commonly used pharmacological and non-pharmacological treatment strategies, and evidence-based clinical practice guidelines for their appropriate management. Furthermore, we discuss risk factors and validated risk-assessment tools for identifying patients most likely to be harmed by chemotherapy and potentially benefit from effective interventions. Finally, we highlight promising emerging supportive-care opportunities for the ever-increasing number of cancer survivors at continuing risk of adverse treatment effects.

Targeting a xenobiotic transporter to ameliorate vincristine-induced sensory neuropathy

Vincristine is a widely used chemotherapeutic drug for the treatment of multiple malignant diseases that causes a dose-limiting peripheral neurotoxicity. There is no clinically effective preventative treatment for vincristine-induced sensory peripheral neurotoxicity (VIPN), and mechanistic details of this side effect remain poorly understood. We hypothesized that VIPN is dependent on transporter-mediated vincristine accumulation in dorsal root ganglion neurons. Using a xenobiotic transporter screen, we identified OATP1B3 as a neuronal transporter regulating the uptake of vincristine. In addition, genetic or pharmacological inhibition of the murine orthologue transporter OATP1B2 protected mice from various hallmarks of VIPN - including mechanical allodynia, thermal hyperalgesia, and changes in digital maximal action potential amplitudes and neuronal morphology - without negatively affecting plasma levels or antitumor effects of vincristine. Finally, we identified α-tocopherol from an untargeted metabolomics analysis as a circulating endogenous biomarker of neuronal OATP1B2 function, and it could serve as a companion diagnostic to guide dose selection of OATP1B-type transport modulators given in combination with vincristine to prevent VIPN. Collectively, our findings shed light on the fundamental basis of VIPN and provide a rationale for the clinical development of transporter inhibitors to prevent this debilitating side effect.

Efficacy of Duloxetine on electrodiagnostic findings of Paclitaxel-induced peripheral neuropathy, does it have a prophylactic effect? A randomized clinical trial

This study aimed to evaluate the efficacy of Duloxetine on electrodiagnostic findings of Paclitaxel-induced peripheral neuropathy in patients with breast cancer. This randomized, double-blind clinical trial was conducted on 40 patients with breast cancer who received Paclitaxel as their first chemotherapy session. All the patients were randomly allocated into two groups, intervention (20 subjects) and placebo (20 subjects). The intervention group received 30 mg duloxetine/day in the first week, followed by 60 mg (twice daily) until 8 weeks. The patient neurotoxicity questionnaire (PNQ) was used to evaluate the severity of neuropathy. Nerve conduction study was also performed. The evaluations were performed at the baseline and 8 weeks after the treatment. Out of 20 subjects in the placebo group, 10 (50%) patients had neurotoxicity (two milds, three moderate, four severe, and one incapacitated), according to PNQ. However, in the duloxetine group, two patients had mild neurotoxicity ( P = 0.03). Significant differences between groups related to the mean of Median Sensory Latency ( P <0.001), Median Motor Latency ( P < 0.001), and Median Motor velocity ( P = 0.001) were reported. However, the relative risk of polyneuropathy between the two groups (relative risk: 1) was not significant. Regarding the results, duloxetine could be an effective treatment for preventing paclitaxel-induced peripheral neuropathy in patients with breast cancer, and an electrodiagnostic study confirmed this effect.

The Therapeutic Potential of Antioxidants in Chemotherapy-Induced Peripheral Neuropathy: Evidence from Preclinical and Clinical Studies

As cancer therapies advance and patient survival improves, there has been growing concern about the long-term adverse effects that patients may experience following treatment, and concerns have been raised about such persistent, progressive, and often irreversible adverse effects. Chemotherapy is a potentially life-extending treatment, and chemotherapy-induced peripheral neuropathy (CIPN) is one of its most common long-term toxicities. At present, strategies for the prevention and treatment of CIPN are still an open problem faced by medicine, and there has been a large amount of previous evidence that oxidative damage is involved in the process of CIPN. In this review, we focus on the lines of defense involving antioxidants that exert the effect of inhibiting CIPN. We also provide an update on the targets and clinical prospects of different antioxidants (melatonin, N-acetylcysteine, vitamins, α-lipoic acid, mineral elements, phytochemicals, nutritional antioxidants, cytoprotectants and synthetic compounds) in the treatment of CIPN with the help of preclinical and clinical studies, emphasizing the great potential of antioxidants as adjuvant strategies to mitigate CIPN.

Identification of a SNP cluster associated with taxane-induced peripheral neuropathy risk in patients being treated for breast cancer using GWAS data derived from a large cooperative group trial

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity of taxanes for which there is no effective intervention. Genomic CIPN risk determination has yielded promising, but inconsistent results. The present study assessed the utility of a collective SNP cluster identified using novel analytics to describe taxane-associated CIPN risk.

METHODS

We analyzed GWAS data derived from ECOG-5103, first identifying SNPs that were most strongly associated with CIPN using Fisher's ratio (FR). We then ranked ordered those SNPs which discriminated CIPN-positive (CIPN +) from CIPN-negative phenotypes based on their discriminatory power and developed the cluster of SNPs which provided the highest predictive accuracy using leave-one-out cross-validation (LOOCV).

RESULTS

Using aggregated genotype data obtained from the previously reported ECOG-5103 clinical trial (in which two different arrays were used, HumanOmniExpress (727,227 SNPs) and HumanOmni1-Quad1 (1,131,857 SNPs)), we identified a 267 SNP cluster which was associated with a CIPN + phenotype with an accuracy of 96.1%.

CONCLUSIONS

A cluster of SNPs was identified which prospectively discriminated patients most likely to develop symptomatic CIPN following taxane exposure as part of a breast cancer chemotherapy regimen. Validation using an independent patient cohort should be performed.

A Pilot Randomized Controlled Trial Evaluating Essential Oils for Chemotherapy-Induced Peripheral Neuropathy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a painful, debilitating consequence of cancer treatment affecting up to 60% of patients. Pharmacological approaches to CIPN are often ineffective and cause adverse effects. Essential oils are an underutilized non-pharmacological approach to pain reduction.

AIMS

To ascertain the efficacy of an essential oil intervention to reduce CIPN.

DESIGN

A single-blind, pilot randomized controlled trial.

METHODS

Participants (n = 27) were stratified by baseline pain scores and randomized to intervention (n = 13) and placebo groups (n = 14). Participants topically-applied the essential oil intervention or placebo every eight hours for six weeks. Pain was assessed using the Short-Form-McGill Pain Questionnaire-2 weekly and the Visual Analogue Scale daily. Quality-of-life was assessed using the Quality-of-Life: CIPN-20 and Quality-of-Life Adult Cancer Survivor questionnaires. Data were analyzed in SPSS using generalized estimating equations.

RESULTS

No significant difference was observed between groups in pain or quality-of-life scores over seven weeks, but improvement was observed in both groups. Participants using the intervention with pain medications showed a significant reduction in pain compared to placebo (p = .001). Educational level (p = .041) and annual income (p = .005) were significant covariates mirroring these social determinates of pain. Older participants felt less negatively about their CIPN (p = .002). Positive placebo effect and spatiotemporal interactions were observed.

CONCLUSIONS

This pilot study demonstrated that participants adhered to the intervention for six weeks. Essential oils have potential direct and adjuvant pain-reducing effects and should be studied further.

PROPERTY: study protocol for a randomized, double-blind, multicenter placebo-controlled trial assessing neurotoxicity in patients with metastatic gastrointestinal cancer taking PHYCOCARE® during oxaliplatin-based chemotherapy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common adverse effects of antineoplastic agents, ranging in prevalence from 19% to over 85%. Clinically, CIPN is a predominantly sensory neuropathy that may be accompanied by motor and autonomic changes of varying intensity and duration. The high prevalence of CIPN among cancer patients makes it a major problem for both patients and survivors, as well as for their health care providers, especially because there is currently no single effective method of preventing CIPN; moreover, the options for treating this syndrome are very limited. Phycocyanin, a biliprotein pigment and an important constituent of the blue-green algae Spirulina platensis, has been reported to possess significant antioxidant and radical-scavenging properties, offering protection against oxidative stress, which is one of the hypothetic mechanisms, between others, of CIPN occurrence.

METHODS

Our hypothesis is that phycocyanin may give protection against oxaliplatin-induced neuropathy in the treatment of gastrointestinal cancers. Our trial will be a randomized double-blind placebo-controlled study with 110 randomized patients suffering from metastatic gastrointestinal adenocarcinoma including esogastric, colorectal, and pancreatic cancers. Patients are being followed up in the gastroenterology or oncology departments of seven French hospitals.

DISCUSSION

Due to the neuropathy, patients need to avoid injury by paying careful attention to home safety; patients' physicians often prescribe over-the-counter pain medications. If validated, our hypothesis should help to limit neurotoxicity without the need to discontinue chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05025826. First published on August 27, 2021.

First-in-Class Dual Hybrid Carbonic Anhydrase Inhibitors and Transient Receptor Potential Vanilloid 1 Agonists Revert Oxaliplatin-Induced Neuropathy

Here, we report for the first time a series of compounds potentially useful for the management of oxaliplatin-induced neuropathy (OINP) able to modulate the human Carbonic Anhydrases (hCAs) as well as the Transient Receptor Potential Vanilloid 1 (TRPV1). All compounds showed effective in vitro inhibition activity toward the main hCAs involved in such a pathology, whereas selected items reported moderate agonism of TRPV1. X-ray crystallographic experiments assessed the binding modes of the two enantiomers (R)-37a and (S)-37b within the hCA II cleft. Although the tails assumed diverse orientations, no appreciable effects were observed for their hCA II affinity. Similarly, the activity of (R)-39a and (S)-39b on TRPV1 was not influenced by the stereocenters. In vivo evaluation of the most promising derivatives (R)-12a, (R)-37a, and the two enantiomers (R)-39a, (S)-39b revealed antihypersensitivity effects in a mouse model of OINP with potent and persistent effect up to 75 min after administration.

Data mining analysis reveals key acupoints and meridians for the treatment of chemotherapy-induced peripheral neuropathy

OBJECTIVE

To explore effective acupoints and combinations for the treatment of chemotherapy-induced peripheral neuropathy (CIPN) METHODS: Clinical controlled trials and randomized controlled trials of acupuncture for CIPN were sourced from PubMed, Embase, Web of Science, and Chinese databases, including the Wanfang database, VIP Journals database, and China National Knowledge Infrastructure database. The quality of eligible research was evaluated based on CONSORT and STRICTA statements. The common acupoints, meridians, and acupoint combinations were determined from acupuncture prescriptions reporting positive effects and were analyzed using SPSS 23.0 and SPSS Modeler 14.1. Finally, a complex network was constructed using Cytoscape 3.8.2 to explore the core acupoints.

RESULTS

The quality of 24 clinical trials was evaluated, and 20 acupuncture prescriptions that reported positive outcomes were included in subsequent data mining analysis. The most frequently used acupoints are ST36, LI11, LI4, LR3, and SP6. Meanwhile, they are also the core acupoints in acupuncture prescriptions according to the complex network with 28 nodes and 177 edges. The most commonly used meridians were the large intestine, stomach, and spleen. Acupoint combinations of LI11 and ST36, SP6 and ST36 were frequently used.

CONCLUSION

Our study provides a reference for the selection of effective acupoints for CIPN treatment and a basis for the effective use of this form of traditional Chinese medicine. Furthermore, we found limitations in the design and implementation of the available clinical research, which should be minimized in future studies.

Targeting OCT2 with Duloxetine to Prevent Oxaliplatin-Induced Peripheral Neurotoxicity

Oxaliplatin-induced peripheral neurotoxicity (OIPN) is a debilitating side effect that afflicts ~90% of patients that is initiated by OCT2-dependent uptake of oxaliplatin in DRG neurons. The antidepressant drug duloxetine has been used to treat OIPN, although its usefulness in preventing this side effect remains unclear. We hypothesized that duloxetine has OCT2-inhibitory properties and can be used as an adjunct to oxaliplatin-based regimens to prevent OIPN. Transport studies were performed in cells stably transfected with mouse or human OCT2 and in isolated mouse DRG neurons ex vivo. Wild-type and OCT2-deficient mice were used to assess effects of duloxetine on hallmarks of OIPN, endogenous OCT2 biomarkers, and the pharmacokinetics of oxaliplatin, and the translational feasibility of a duloxetine-oxaliplatin combination was evaluated in various models of colorectal cancer. We found that duloxetine potently inhibited the OCT2-mediated transport of several xenobiotic substrates, including oxaliplatin, in a reversible, concentration-dependent manner, and independent of species and cell context. Furthermore, duloxetine restricted access of these substrates to DRG neurons ex vivo and prevented OIPN in wild-type mice to a degree similar to the complete protection observed in OCT2-deficient mice, without affecting the plasma levels of oxaliplatin. Importantly, the uptake and cytotoxicity of oxaliplatin in tumor cell lines in vitro and in vivo were not negatively influenced by duloxetine. The observed OCT2-targeting properties of duloxetine, combined with the potential for clinical translation, provide support for its further exploration as a therapeutic candidate for studies aimed at preventing OIPN in cancer patients requiring treatment with oxaliplatin.

Significance

We found that duloxetine has potent OCT2-inhibitory properties and can diminish excessive accumulation of oxaliplatin into DRG neurons. In addition, pre-treatment of mice with duloxetine prevented OIPN without significantly altering the plasma pharmacokinetics and antitumor properties of oxaliplatin. These results suggest that intentional inhibition of OCT2-mediated transport by duloxetine can be employed as a prevention strategy to ameliorate OIPN without compromising the effectiveness of oxaliplatin-based treatment.

NGF monoclonal antibody DS002 alleviates chemotherapy-induced peripheral neuropathy in rats

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the pervasive side effects of chemotherapy, leading to poor quality of life in cancer patients. Discovery of powerful analgesics for CIPN is an urgent and substantial clinical need. Nerve growth factor (NGF), a classic neurotrophic factor, has been identified as a potential therapeutic target for pain. In this study, we generated a humanized NGF monoclonal antibody (DS002) that most effectively blocked the interaction between NGF and tropomyosin receptor kinase A (TrkA). We showed that DS002 blocked NGF binding to TrkA in a dose-dependent manner with an IC50 value of 6.6 nM; DS002 dose-dependently inhibited the proliferation of TF-1 cells by blocking the TrkA-mediated downstream signaling pathway. Furthermore, DS002 did not display noticeable species differences in its binding and blocking abilities. In three chemotherapy-induced rat models of CIPN, subcutaneous injection of DS002 produced a significant prophylactic effect against paclitaxel-, cisplatin- and vincristine-induced peripheral neuropathy. In conclusion, we demonstrate for the first time that an NGF inhibitor effectively alleviates pain in animal models of CIPN. DS002 has the potential to treat CIPN pain in the clinic.

The Combination of Zinc and Melatonin Enhanced Neuroprotection and Attenuated Neuropathy in Oxaliplatin-Induced Neurotoxicity

Objective

The present study was designed to investigate the possible synergistic effects of melatonin with zinc in the prevention and treatment of oxaliplatin-induced neurotoxicity in rats.

Methodology

Forty-eight male Wistar albino rats were used and randomly allocated into six groups: The negative control group, oxaliplatin group, zinc + oxaliplatin group, melatonin + oxaliplatin group, zinc + melatonin + oxaliplatin prevention-approach group, and zinc + melatonin + oxaliplatin treatment-approach group. The thermal nociceptive/hyperalgesia tests were performed. Brain tissue homogenate was used for measuring GFAP, NCAM, TNF α, MAPK 14, NF-kB, GPX, and SOD. Brain tissue was sent for histopathological and immunohistochemistry studies.

Results

The combination therapies showed improvement in the behavioral tests. A significant increase in GPX and SOD with a significant decrease in GFAP levels resulted in the prevention approach. TNF α decreased significantly in the treatment approach. No significant changes were seen in NCAM, NFkB, and MAPK-14. The histopathological findings support the biochemical results. Additionally, immunohistochemistry revealed a significant attenuation of p53 and a non-significant decrease in Bcl2 levels in the combination groups.

Conclusion

The combination of zinc with melatonin for the prevention approach was effective in attenuating neurotoxicity induced by oxaliplatin. The proposed mechanisms are boosting the antioxidant system and attenuating the expression of p53, GFAP, and TNF-α.

The effectiveness and safety of acupuncture for chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis

Objectives

This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of acupuncture on chemotherapy-induced peripheral neuropathy (CIPN).

Methods

We searched for relevant randomized controlled trials (RCTs) in PubMed, Cochrane Library, and Embase databases from their inception to 1 April 2022. The Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx), Brief Pain Inventory-Short Form (BPI-SF), the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core30 (EORTC QLQ-C30), Numerical Rating Scale (NRS), and adverse events were the outcome measures. All studies had at least one of these outcome measures. Mean differences (MDs) with 95% confidence intervals (CIs) were assessed in the meta-analysis using the RevMan 5.3 software.

Results

Five studies were included in the analysis. The results showed that acupuncture and placebo acupuncture were not significantly different in reducing chemotherapy-induced neurotoxicity and functional disability (random-effects estimates; MD: 4.30; 95% CI: −0.85~9.45; P = 0.10; I² = 74%). Acupuncture was better than placebo acupuncture in reducing pain severity and pain interference with patients' daily function (fixed-effect estimates; MD: −1.14; 95% CI: 1.87 to −0.42; P = 0.002; I² = 13%). Acupuncture was not significantly different from placebo acupuncture in relieving CIPN symptoms (MD: −0.81; 95% CI: −2.02 to 0.40, P = 0.19). Acupuncture improved quality of life better than placebo acupuncture (MD: 10.10; 95% CI: 12.34 to 17.86, P = 0.01). No severe adverse events were recorded in all five studies.

Conclusion

This meta-analysis suggests that acupuncture may be more effective and safer in reducing pain severity and pain interference with patients' daily function than placebo acupuncture. Additionally, acupuncture may improve the quality of life of patients with CIPN. However, large sample size studies are needed to confirm this conclusion.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=324930, identifier: CRD42022324930.

Case report: Significant relief of linezolid-induced peripheral neuropathy in a pre-XDR-TB case after acupuncture treatment

The revised WHO guidelines on multidrug- or rifampicin-resistant tuberculosis (MDR/RR-TB) include linezolid in the core drug group. Common adverse events of prolonged linezolid use are bone marrow suppression and peripheral neuropathy (PN). Available measures against linezolid-induced PN (LIPN) often have insignificant effects, leading to linezolid discontinuation and a decline in the success rate of MDR/RR-TB treatment. Acupuncture treatment is a symptomatic treatment measure from traditional Chinese medicine (TCM) to relieve pain with overall very low evidence and has never been reported in LIPN. The pilot use of acupuncture in a pre-extensively drug-resistant (XDR)-TB (a more severe form of MDR/RR-TB) patient exhibited significant improvements in LIPN and thus maintained linezolid in the regimen for a longer period.

Transporters and Toxicity: Insights from the International Transporter Consortium Workshop 4

Over the last decade, significant progress been made in elucidating the role of membrane transporters in altering drug disposition, with important toxicological consequences due to changes in localized concentrations of compounds. The topic of "Transporters and Toxicity" was recently highlighted as a scientific session at the International Transporter Consortium (ITC) Workshop 4 in 2021. The current white paper is not intended to be an extensive review on the topic of transporters and toxicity but an opportunity to highlight aspects of the role of transporters in various toxicities with clinically relevant implications as covered during the session. This includes a review of the role of solute carrier transporters in anticancer drug-induced organ injury, transporters as key players in organ barrier function, and the role of transporters in metal/metalloid toxicity.

Cisplatin Neurotoxicity Targets Specific Subpopulations and K+ Channels in Tyrosine-Hydroxylase Positive Dorsal Root Ganglia Neurons

Among the features of cisplatin chemotherapy-induced peripheral neuropathy are chronic pain and innocuous mechanical hypersensitivity. The complete etiology of the latter remains unknown. Here, we show that cisplatin targets a heterogeneous population of tyrosine hydroxylase-positive (TH⁺) primary afferent dorsal root ganglion neurons (DRGNs) in mice, determined using single-cell transcriptome and electrophysiological analyses. TH⁺ DRGNs regulate innocuous mechanical sensation through C-low threshold mechanoreceptors. A differential assessment of wild-type and vitamin E deficient TH⁺ DRGNs revealed heterogeneity and specific functional phenotypes. The TH⁺ DRGNs comprise; fast-adapting eliciting one action potential (AP; 1-AP), moderately-adapting (≥2-APs), in responses to square-pulse current injection, and spontaneously active (SA). Cisplatin increased the input resistance and AP frequency but reduced the temporal coding feature of 1-AP and ≥2-APs neurons. By contrast, cisplatin has no measurable effect on the SA neurons. Vitamin E reduced the cisplatin-mediated increased excitability but did not improve the TH⁺ neuron temporal coding properties. Cisplatin mediates its effect by targeting outward K⁺ current, likely carried through K2P18.1 (Kcnk18), discovered through the differential transcriptome studies and heterologous expression. Studies show a potential new cellular target for chemotherapy-induced peripheral neuropathy and implicate the possible neuroprotective effects of vitamin E in cisplatin chemotherapy.

Discovery of Potential Neuroprotective Agents against Paclitaxel-Induced Peripheral Neuropathy

Chemotherapy-induced neurotoxicity is a common adverse effect of cancer treatment. No medication has been shown to be effective in the prevention or treatment of chemotherapy-induced neurotoxicity. Using minoxidil as an initial template for structural modifications in conjunction with an in vitro neurite outgrowth assay, an image-based high-content screening platform, and mouse behavior models, an effective neuroprotective agent CN016 was discovered. Our results showed that CN016 could inhibit paclitaxel-induced inflammatory responses and infiltration of immune cells into sensory neurons significantly. Thus, the suppression of proinflammatory factors elucidates, in part, the mechanism of action of CN016 on alleviating paclitaxel-induced peripheral neuropathy. Based on excellent efficacy in improving behavioral functions, high safety profiles (MTD > 500 mg/kg), and a large therapeutic window (MTD/MED > 50) in mice, CN016 might have great potential to become a peripherally neuroprotective agent to prevent neurotoxicity caused by chemotherapeutics as typified by paclitaxel.

Endoplasmic Reticulum Stress in Chemotherapy-Induced Peripheral Neuropathy: Emerging Role of Phytochemicals

Chemotherapy-induced peripheral neuropathy (CIPN) is a significant dose-limiting long-term sequela in cancer patients undergoing treatment, often leading to discontinuation of treatment. No established therapy exists to prevent and/or ameliorate CIPN. Reactive oxygen species (ROS) and mitochondrial dysregulation have been proposed to underlie the pathobiology of CIPN. However, interventions to prevent and treat CIPN are largely ineffective. Additional factors and mechanism-based targets need to be identified to develop novel strategies to target CIPN. The role of oxidative stress appears to be central, but the contribution of endoplasmic reticulum (ER) stress remains under-examined in the pathobiology of CIPN. This review describes the significance of ER stress and its contribution to CIPN, the protective role of herbal agents in countering ER stress in nervous system-associated disorders, and their possible repurposing for preventing CIPN.

Updates in the Treatment of Chemotherapy-Induced Peripheral Neuropathy

OPINION STATEMENT

Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity associated with treatment with platinum-based agents, taxanes, vinca alkaloids, and other specific agents. The long-term consequences of this condition can result in decreased patient quality of life and can lead to reduced dose intensity, which can negatively impact disease outcomes. There are currently no evidence-based preventative strategies for CIPN and only limited options for treatment. However, there are several strategies that can be utilized to improve patient experience and outcomes as more data are gathered in the prevention and treatment setting. Before treatment, patient education on the potential side effects of chemotherapy is key, and although trials have been limited, recommending exercise and a healthy lifestyle before and while undergoing chemotherapy may provide some overall benefit. In patients who develop painful CIPN, our approach is to offer duloxetine and titrate up to 60 mg daily. Chemotherapy doses may also need to be reduced if intolerable symptoms develop during treatment. Some patients may also try acupuncture and physical therapy to help address their symptoms, although this can be limited by cost, time commitment, and patient motivation. Additionally, data on these modalities are currently limited, as studies are ongoing. Overall, approaching each patient on an individual level and tailoring treatment options for them based on overall physical condition, their disease burden, goals of care and co-morbid health conditions, and willingness to trial different approaches is necessary when addressing CIPN.

Pharmacogenomics in Cytotoxic Chemotherapy of Cancer

Pharmacogenetic testing in patients with cancer requiring cytotoxic chemotherapy offers the potential to predict, prevent, and mitigate chemotherapy-related toxicities. While multiple drug-gene pairs have been identified and studied, few drug-gene pairs are currently used routinely in the clinical status. Here we review what is known, theorized, and unknown regarding the use of pharmacogenetic testing in cancer.

Considerations for a Reliable In Vitro Model of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is widely recognized as a potentially severe toxicity that often leads to dose reduction or discontinuation of cancer treatment. Symptoms may persist despite discontinuation of chemotherapy and quality of life can be severely compromised. The clinical symptoms of CIPN, and the cellular and molecular targets involved in CIPN, are just as diverse as the wide variety of anticancer agents that cause peripheral neurotoxicity. There is an urgent need for extensive molecular and functional investigations aimed at understanding the mechanisms of CIPN. Furthermore, a reliable human cell culture system that recapitulates the diversity of neuronal modalities found in vivo and the pathophysiological changes that underlie CIPN would serve to advance the understanding of the pathogenesis of CIPN. The demonstration of experimental reproducibility in a human peripheral neuronal cell system will increase confidence that such an in vitro model is clinically useful, ultimately resulting in deeper exploration for the prevention and treatment of CIPN. Herein, we review current in vitro models with a focus on key characteristics and attributes desirable for an ideal human cell culture model relevant for CIPN investigations.

Targeting strategies for oxaliplatin-induced peripheral neuropathy: clinical syndrome, molecular basis, and drug development

Oxaliplatin (OHP)-induced peripheral neurotoxicity (OIPN) is a severe clinical problem and potentially permanent side effect of cancer treatment. For the management of OIPN, accurate diagnosis and understanding of significant risk factors including genetic vulnerability are essential to improve knowledge regarding the prevalence and incidence of OIPN as well as enhance strategies for the prevention and treatment of OIPN. The molecular mechanisms underlying OIPN are complex, with multi-targets and various cells causing neuropathy. Furthermore, mechanisms of OIPN can reinforce each other, and combination therapies may be required for effective management. However, despite intense investigation in preclinical and clinical studies, no preventive therapies have shown significant clinical efficacy, and the established treatment for painful OIPN is limited. Duloxetine is the only agent currently recommended by the American Society of Clinical Oncology. The present article summarizes the most recent advances in the field of studies on OIPN, the overview of the clinical syndrome, molecular basis, therapy development, and outlook of future drug candidates. Importantly, closer links between clinical pain management teams and oncology will advance the effectiveness of OIPN treatment, and the continued close collaboration between preclinical and clinical research will facilitate the development of novel prevention and treatments for OIPN.

Inhibition of dual leucine zipper kinase prevents chemotherapy-induced peripheral neuropathy and cognitive impairments

ABSTRACT

Chemotherapy-induced peripheral neuropathy (CIPN) and chemotherapy-induced cognitive impairments (CICI) are common, often severe neurotoxic side effects of cancer treatment that greatly reduce quality of life of cancer patients and survivors. Currently, there are no Food and Drug Administration-approved agents for the prevention or curative treatment of CIPN or CICI. The dual leucine zipper kinase (DLK) is a key mediator of axonal degeneration that is localized to axons and coordinates the neuronal response to injury. We developed a novel brain-penetrant DLK inhibitor, IACS'8287, which demonstrates potent and highly selective inhibition of DLK in vitro and in vivo. Coadministration of IACS'8287 with the platinum derivative cisplatin prevents mechanical allodynia, loss of intraepidermal nerve fibers in the hind paws, cognitive deficits, and impairments in brain connectivity in mice, all without interfering with the antitumor activity of cisplatin. The protective effects of IACS'8287 are associated with preservation of mitochondrial function in dorsal root ganglion neurons and in brain synaptosomes. In addition, RNA sequencing analysis of dorsal root ganglia reveals modulation of genes involved in neuronal activity and markers for immune cell infiltration by DLK inhibition. These data indicate that CIPN and CICI require DLK signaling in mice, and DLK inhibitors could become an attractive treatment in the clinic when coadministered with cisplatin, and potentially other chemotherapeutic agents, to prevent neurotoxicities as a result of cancer treatment.

Evolving Techniques in Peripheral Nerve Regeneration

Reliable and robust peripheral nerve regeneration after a nerve injury and repair remains an elusive goal. A variety of strategies have been proposed to mitigate the effects of Wallerian degeneration (through molecular therapies), enhance axonal regeneration across the repair site (through electrical stimulation and gene therapy), and explore alternatives to suture coaptation (through the fusion of transected ends). Although most of these techniques are in their infancy, animal data and some clinical trials have demonstrated promise for improving the restoration of function after these devastating injuries.

Drug-Induced Peripheral Neuropathy: Diagnosis and Management

Peripheral neuropathy comes in all shapes and forms and is a disorder which is found in the peripheral nervous system. It can have an acute or chronic onset depending on the multitude of pathophysiologic mechanisms involving different parts of nerve fibers. A systematic approach is highly beneficial when it comes to cost-effective diagnosis. More than 30 causes of peripheral neuropathy exist ranging from systemic and auto-immune diseases, vitamin deficiencies, viral infections, diabetes, etc. One of the major causes of peripheral neuropathy is drug induced disease, which can be split into peripheral neuropathy caused by chemotherapy or by other medications. This review deals with the latest causes of drug induced peripheral neuropathy, the population involved, the findings on physical examination and various workups needed and how to manage each case.

Review of the Role of the Brain in Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common, debilitating, and dose-limiting side effect of many chemotherapy regimens yet has limited treatments due to incomplete knowledge of its pathophysiology. Research on the pathophysiology of CIPN has focused on peripheral nerves because CIPN symptoms are felt in the hands and feet. However, better understanding the role of the brain in CIPN may accelerate understanding, diagnosing, and treating CIPN. The goals of this review are to (1) investigate the role of the brain in CIPN, and (2) use this knowledge to inform future research and treatment of CIPN. We identified 16 papers using brain interventions in animal models of CIPN and five papers using brain imaging in humans or monkeys with CIPN. These studies suggest that CIPN is partly caused by (1) brain hyperactivity, (2) reduced GABAergic inhibition, (3) neuroinflammation, and (4) overactivation of GPCR/MAPK pathways. These four features were observed in several brain regions including the thalamus, periaqueductal gray, anterior cingulate cortex, somatosensory cortex, and insula. We discuss how to leverage this knowledge for future preclinical research, clinical research, and brain-based treatments for CIPN.

Diabetes mellitus as a risk factor for chemotherapy-induced peripheral neuropathy: a meta-analysis

BACKGROUND

To identify the association between diabetes mellitus (DM) and the risk of chemotherapy-induced peripheral neuropathy (CIPN) through a systematic review and meta-analysis.

METHODS

An electronic literature search was conducted in PubMed, Embase, Web of Science, the Wanfang database, the VIP Journals database (CQVIP), the China National Knowledge Infrastructure (CNKI) database, and the China Biology Medicine database (Sinomed) between January 2010 and January 2021. Articles were included if they investigated CIPN and DM. Stata 15.1 was used to analyze the data.

RESULTS

We examined 8923 cancer patients from 25 studies comprising 9 cohort studies and 16 case-control studies. Meta-analysis showed that there was a statistically significant positive correlation between DM and CIPN (odds ratio [OR] = 1.60, 95% confidence interval [CI] = 1.38-1.85, P < 0.001). Egger's test (P = 0.824) showed no evidence of publication bias. The positive associations did not significant differ by study type, study quality, evaluation instrument, and type of antineoplastic drug. Omission of any single study had little effect on the combined risk estimate. Little evidence of heterogeneity was observed.

CONCLUSION

This meta-analysis provides evidence of a significant positive association between DM and risk of CIPN. Furthermore, a more detailed evaluation is warranted for cancer patients with diabetes when they are treated with antineoplastic drugs that have the potential to cause peripheral neuropathy.

Acupuncture for Paclitaxel-Induced Peripheral Neuropathy: A Review of Clinical and Basic Studies

Paclitaxel-induced peripheral neuropathy (PIPN) is a common and intractable side effect of the conventional chemotherapeutic agent paclitaxel. Acupuncture has been reported as an effective alternative therapy in treatment of PIPN in both basic studies and clinical trials. However, there is a lack of comprehensive surveys to summarize the action of acupuncture in management of PIPN. In this review, we briefly demonstrate the basic pathology of PIPN, which includes the activation of ion channels, mitochondrial dysfunction, disruption of axonal transport and also neuro-inflammatory involvement. Meanwhile, we review both the clinical and basic studies as an emphasis to give a general overview of the therapeutic effect of acupuncture against PIPN. Finally, we summarize the current known mechanisms underlying the action of acupuncture against PIPN mainly at peripheral and spinal levels, which include various neurotransmitters, multiple receptors, different types of enzymes and molecules. In conclusion, acupuncture could be considered as a potential alternative therapy in treatment of PIPN, and further clinical and experimental studies are called for in the future.

Cilostazol is an effective causal therapy for preventing paclitaxel-induced peripheral neuropathy by suppression of Schwann cell dedifferentiation

Chemotherapy-induced peripheral neuropathy (CIPN) can lead to discontinuation of chemotherapy and is consequently a serious impediment to effective cancer treatment. Due to our limited understanding of mechanisms underlying the pathogenesis of CIPN, no causal therapy has been approved for relief of this condition. We previously demonstrated that taxanes (paclitaxel and docetaxel) induce Schwann cell dedifferentiation, characterized by increased expression of p75 and galectin-3, ultimately leading to demyelination. These changes appear to be responsible for CIPN pathogenesis. This study was designed to identify a novel candidate therapeutic for CIPN with the ability to suppress paclitaxel-induced Schwann cell dedifferentiation. Given that elevation of cyclic adenosine monophosphate (cAMP) signaling participates in Schwann cell differentiation, we performed immunocytochemical screening of phosphodiesterase (PDE) inhibitors. We found that the PDE3 inhibitor cilostazol strongly promoted differentiation of primary cultures of rat Schwann cells via a mechanism involving cAMP/exchange protein directly activated by cAMP (Epac) signaling. Co-treatment with cilostazol prevented paclitaxel-induced dedifferentiation of Schwann cell cultures and demyelination in a mixed culture of Schwann cells and dorsal root ganglia neurons. Notably, continuous oral administration of cilostazol suppressed Schwann cell dedifferentiation within the sciatic nerve and the development of mechanical hypersensitivity in a mouse model of paclitaxel-related CIPN. Importantly, cilostazol potentiated, rather than inhibited, the anti-cancer effect of paclitaxel on the human breast cancer cell line MDA-MB-231. These findings highlight the potential utility of cilostazol as a causal therapeutic that avoids the development of paclitaxel-related CIPN without compromising anti-cancer properties.

Decursin Alleviates Mechanical Allodynia in a Paclitaxel-Induced Neuropathic Pain Mouse Model

Chemotherapy-induced neuropathic pain (CINP) is a severe adverse effect of platinum- and taxane-derived anticancer drugs. The pathophysiology of CINP includes damage to neuronal networks and dysregulation of signal transduction due to abnormal Ca²⁺ levels. Therefore, methods that aid the recovery of neuronal networks could represent a potential treatment for CINP. We developed a mouse model of paclitaxel-induced peripheral neuropathy, representing CINP, to examine whether intrathecal injection of decursin could be effective in treating CINP. We found that decursin reduced capsaicin-induced intracellular Ca²⁺ levels in F11 cells and stimulated neurite outgrowth in a concentration-dependent manner. Decursin directly reduced mechanical allodynia, and this improvement was even greater with a higher frequency of injections. Subsequently, we investigated whether decursin interacts with the transient receptor potential vanilloid 1 (TRPV1). The web server SwissTargetPrediction predicted that TRPV1 is one of the target proteins that may enable the effective treatment of CINP. Furthermore, we discovered that decursin acts as a TRPV1 antagonist. Therefore, we demonstrated that decursin may be an important compound for the treatment of paclitaxel-induced neuropathic pain that functions via TRPV1 inhibition and recovery of damaged neuronal networks.

Topical Costus sp. Preparation as Palliative Care for Chemotherapy-Induced Peripheral Neuropathy of Patients: A Randomized Placebo-Controlled Pilot Trial

Objectives: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of various anticancer regimens with different sensory-motor abnormalities in patients. The aim of this study was to examine the feasibility of using Costus sp. oil as a palliative treatment in such patients. Design: This was a pilot randomized placebo-controlled double-blind clinical study. Settings/Location: Imam Hossein Hospital, Tehran, Iran. Subjects: Patients 18-80 years of age undergoing chemotherapy treatment recently or during the last 6 months were enrolled after meeting the inclusion criteria. Interventions: The intervention group used Costus sp. as a topical ointment and the placebo group used topical paraffin for 4 weeks. Outcome measures: Feasibility of recruitment, including treatment acceptability (evaluated as number of patients leaving the study early), and compliance (defined as consumption of a minimum 80% of the ointment) with the intervention were assessed. Neuropathic pain change was defined as the secondary outcome, too. Results: Totally, 50 out of 73 participants were identified eligible and were randomly divided into intervention or placebo groups. There was no significant difference between groups in terms of sociodemographic data. At the end of the study, 24% (confidence interval [95% CI]: 9-45) (intervention group) and 12% (95% CI: 2-31) (placebo group) of patients revealed treatment unacceptability. Meanwhile, 12% (95% CI: 2-31) in the intervention group and 28% (95% CI: 12-49) in the placebo group did not show the compliance. Moreover, according to patients' records, pain reduction was higher in the intervention group compared to the placebo group (p = 0.001). Conclusions: This preliminary study showed that topical use of Costus sp. was feasible and acceptable in patients suffering from CIPN.

Supportive Care: Low Cost, High Value

Supportive care aims to prevent and manage adverse effects of cancer and its treatment across the entire disease continuum. Research and clinical experience in dedicated centers have demonstrated that early appropriate supportive care interventions improve symptoms, quality of life, and overall survival in a cost-effective manner. The challenge is to assess symptoms and needs with validated tools regularly and, ideally, between clinic appointments; electronic patient-reported outcome measures and dedicated easily accessible supportive care units can help. As management of certain problems improves, others come to the fore. Cancer-related fatigue and malnutrition are very frequent and need regular screening, assessment of treatable causes, and early intervention to improve. Pharmacologic agents and phytopharmaceuticals are of little use, but other interventions are valuable: physical exercise, counseling on fatigue, and cognitive behavioral therapy/mind-body interventions (e.g., for fatigue). Nutrition should be oral, rich in proteins, and accompanied by muscle training adapted to the patient's condition. Psychological and societal counseling is often useful; nausea or other problems such as gastrointestinal dysmotility or metabolic derangements must be tackled. Chemotherapy-induced peripheral neuropathy frequently worsens quality of life and has no established prevention strategy (notwithstanding current interest in cryotherapy and compression therapy) and thus requires careful assessment of patient predisposition to develop it with the consideration of feasible dose and treatment alternatives. When painful, duloxetine helps. Nonpharmacologic strategies, including acupuncture, physical exercise, cryotherapy/compression, and scrambler therapy, are promising but require large phase III trials to become the accepted standard. Personalization of chemotherapy, dependent on realistic goals, is key.

Emerging Pharmacological and Non-Pharmacological Therapeutics for Prevention and Treatment of Chemotherapy-Induced Peripheral Neuropathy

Simple Summary

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and persistent complication of commonly used chemotherapy drugs. This article provides an overview of emerging therapeutics for the prevention and treatment of CIPN and focuses on pharmacological strategies that are derived from novel mechanistic insights and have the potential to be translated into clinically beneficial approaches. It is our contention to call for fostering collaboration between basic and clinical researchers to improve the development of effective strategies.

Abstract

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event of several first-line chemotherapeutic agents, including platinum compounds, taxanes, vinca alkaloids, thalidomide, and bortezomib, which negatively affects the quality of life and clinical outcome. Given the dearth of effective established agents for preventing or treating CIPN, and the increasing number of cancer survivors, there is an urgent need for the identification and development of new, effective intervention strategies that can prevent or mitigate this debilitating side effect. Prior failures in the development of effective interventions have been due, at least in part, to a lack of mechanistic understanding of CIPN and problems in translating this mechanistic understanding into testable hypotheses in rationally-designed clinical trials. Recent progress has been made, however, in the pathogenesis of CIPN and has provided new targets and pathways for the development of emerging therapeutics that can be explored clinically to improve the management of this debilitating toxicity. This review focuses on the emerging therapeutics for the prevention and treatment of CIPN, including pharmacological and non-pharmacological strategies, and calls for fostering collaboration between basic and clinical researchers to improve the development of effective strategies.

Neuronal uptake transporters contribute to oxaliplatin neurotoxicity in mice

Peripheral neurotoxicity is a debilitating condition that afflicts up to 90% of patients with colorectal cancer receiving oxaliplatin-containing therapy. Although emerging evidence has highlighted the importance of various solute carriers to the toxicity of anticancer drugs, the contribution of these proteins to oxaliplatin-induced peripheral neurotoxicity remains controversial. Among candidate transporters investigated in genetically engineered mouse models, we provide evidence for a critical role of the organic cation transporter 2 (OCT2) in satellite glial cells in oxaliplatin-induced neurotoxicity, and demonstrate that targeting OCT2 using genetic and pharmacological approaches ameliorates acute and chronic forms of neurotoxicity. The relevance of this transport system was verified in transporter-deficient rats as a secondary model organism, and translational significance of preventive strategies was demonstrated in preclinical models of colorectal cancer. These studies suggest that pharmacological targeting of OCT2 could be exploited to afford neuroprotection in cancer patients requiring treatment with oxaliplatin.

Network Pharmacology and Experimental Evidence Identify the Mechanism of Astragaloside IV in Oxaliplatin Neurotoxicity

Background and Objective

Neurotoxicity is a common side effect of oxaliplatin; the effect of current drugs such as methylcobalamin and gabapentine is not obvious. Astragaloside IV (AS-IV) is an important active ingredient of Astragali Radix, which can protect the nervous system and inhibit tumor growth to a certain extent. However, whether AS-IV can reduce oxaliplatin neurotoxicity and its molecular mechanism remain unclear.

Methods

The network pharmacology method was used to determine the collective targets of AS-IV and oxaliplatin neurotoxicity. The model of neurotoxicity was established by intraperitoneal injection of oxaliplatin in rats. Bodyweight, mechanical withdrawal threshold (MWT), cold allodynia, and nerve conduction velocity (NCV) were examined, pathological changes were observed by hematoxylin-eosin staining, number of Nissl bodies were assessed by Nissl staining, the key collective targets were measured by spectrophotometry and immunohistochemistry.

Results

Through network pharmacological analysis, 25 collective targets of AS-IV and oxaliplatin neurotoxicity were identified, mainly related to inflammation and oxidative stress. AS-IV could increase body weight, elevate MWT, and reduce cold allodynia of model rats, it also raised NCV. Neuropathology was improved and the number of Nissl bodies was increased by AS-IV administration. It reduced TNF-α, IL-6, and IL-1β in the spinal cord of model rats to inhibit inflammation; it also decreased MDA, raised SOD, CAT, and GSH-Px in the spinal cord of model rats to block oxidative stress.

Conclusion

AS-IV improves oxaliplatin neurotoxicity by regulating neuroinflammation and oxidative stress; the results can provide a new perspective for the potential treatment strategy of oxaliplatin neurotoxicity.

APE1/Ref-1 - One Target with Multiple Indications: Emerging Aspects and New Directions

In the realm of DNA repair, base excision repair (BER) protein, APE1/Ref-1 (Apurinic/Apyrimidinic Endonuclease 1/Redox Effector - 1, also called APE1) has been studied for decades. However, over the past decade, APE1 has been established as a key player in reduction-oxidation (redox) signaling. In the review by Caston et al. (The multifunctional APE1 DNA repair-redox signaling protein as a drug target in human disease), multiple roles of APE1 in cancer and other diseases are summarized. In this Review, we aim to expand on the contributions of APE1 to various diseases and its effect on disease progression. In the scope of cancer, more recent roles for APE1 have been identified in cancer cell metabolism, as well as chemotherapy-induced peripheral neuropathy (CIPN) and inflammation. Outside of cancer, APE1 signaling may be a critical factor in inflammatory bowel disease (IBD) and is also an emergent area of investigation in retinal ocular diseases. The ability of APE1 to regulate multiple transcription factors (TFs) and therefore multiple pathways that have implications outside of cancer, makes it a particularly unique and enticing target. We discuss APE1 redox inhibitors as a means of studying and potentially combating these diseases. Lastly, we examine the role of APE1 in RNA metabolism. Overall, this article builds on our previous review to elaborate on the roles and conceivable regulation of important pathways by APE1 in multiple diseases.

An overview of ongoing clinical trials assessing pharmacological therapeutic strategies to manage chemotherapy-induced peripheral neuropathy, based on preclinical studies in rodent models

Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting side effect induced by a variety of chemotherapeutic agents. Symptoms are mainly sensory: pain, tingling, numbness, and temperature sensitivity. They may require the tapering of chemotherapy regimens or even their cessation; thus, the prevention/treatment of CIPN is critical to increase effectiveness of cancer treatment. However, CIPN management is mainly based on conventional neuropathic pain treatments, with poor clinical efficacy. Therefore, significant effort is made to identify new pharmacological targets to prevent/treat CIPN. Animal modeling is a key component in predicting human response to drugs and in understanding the pathophysiological mechanisms underlying CIPN. In fact, studies performed in rodents highlighted several pharmacological targets to treat/prevent CIPN. This review provides updated information about ongoing clinical trials testing drugs for the management of CIPN and presents some of their proof-of-concept studies conducted in rodent models. The presented drugs target oxidative stress, renin-angiotensin system, glutamatergic neurotransmission, sphingolipid metabolism, neuronal uptake transporters, nicotinamide adenine dinucleotide metabolism, endocannabinoid system, transient receptor potential channels, and serotoninergic receptors. As some clinical trials focus on the effect of the drugs on pain, others evaluate their efficacy by assessing general neuropathy. Moreover, based on studies conducted in rodent models, it remains unclear if some of the tested drugs act in an antinociceptive fashion or have neuroprotective properties. Thus, further investigations are needed to understand their mechanism of action, as well as a global standardization of the methods used to assess efficacy of new therapeutic strategies in the treatment of CIPN.

Targeting drug transporters to prevent chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy is a debilitating toxicity that adversely affects patient quality and course of treatment. Recent findings have demonstrated that the etiology of peripheral neuropathy is dependent on transporter-mediated accumulation in dorsal root ganglia, and targeting this mechanism can afford neurological protection without compromising therapeutic efficacy.

Diffuse tensor imaging of lower extremities: a novel MR imaging technique for chemotherapy-induced peripheral neuropathy

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is caused by drug-induced damage to the axons which is not detected easily due to lack of reliable, clinically applicable modalities. Diffuse tensor imaging (DTI) allows for quantitative measurements of fractional anisotropy (FA) and apparent diffusion coefficient (ADC), which have been shown to detect nerve injury by Magnetic Resonance Imaging (MRI).

METHODS

We sought to evaluate if DTI could be used for detection of CIPN in patients with breast cancer treated with a taxane. Patients with h/o exposure to neurotoxic chemotherapy, diabetes, or peripheral neuropathy were excluded. Patients completed pre- and post-chemotherapy MRI of bilateral legs and FACT&GOG-Ntx. Genotyping of single-nucleotide variations (SNVs) was performed to detect known associations with CIPN.

RESULTS

We had 14 evaluable patients in this prospective trial. Mean FA values post-chemotherapy were significantly lower than baseline at mid-calf (p < 0.0001) and ankle (p = 0.03). We did not find any significant change in mean ADC values. In patients without symptomatic neuropathy, mean FA values decreased more than symptomatic patients at mid-calf (p < 0.001). Of the 41 genotyped SNVs, only rs8110536 was found to be significantly associated with development of CIPN.

CONCLUSIONS

Our results show that FA values are indicative of CIPN and differential changes in FA values in symptomatic versus asymptomatic patients highlights its potential to be further studied as a predictive biomarker for CIPN. This is the first study to highlight a non-invasive, imaging based, objective biomarker which, if validated, can be translated into clinic easily.