Expression of mitochondrial dysfunction-related genes and pathways in paclitaxel-induced peripheral neuropathy in breast cancer survivors

Mitochondrial A3 Adenosine Receptor as a Mechanism for the Protective Effects of A3AR Agonists on Chemotherapy-Induced Neuropathic Pain

Alterations in mitochondrial function are the linchpin in numerous disease states including in the development of chemotherapy-induced neuropathic pain (CIPN), a major dose-limiting toxicity of widely used chemotherapeutic cytotoxins. In CIPN, mitochondrial dysfunction is characterized by deficits in mitochondrial bioenergetics (e.g., decreased ATP production) that are thought to drive the degeneration of the peripheral nerve sensory axon terminal sensory arbors in the skin (the intraepidermal nerve fibers; IENFs) and induce abnormal spontaneous discharge in peripheral nerve sensory axons. Preserving mitochondrial function is anticipated to prevent CIPN. We have now discovered that the G-protein-coupled receptor, A3 adenosine receptor subtype (A3AR), is expressed on the mitochondrial outer membrane. Ex vivo application of a highly selective A3AR agonist, MRS5980, to saphenous nerve microfilaments harvested from male oxaliplatin-treated rats reversed the loss in ATP production underscoring mitoprotective effects resulting from A3AR activation on mitochondria. Moreover, in vivo administration of A3AR agonists to rats during oxaliplatin treatment was associated with reduced IENF loss and a lower incidence of spontaneous discharge in peripheral afferent axons. These effects are accompanied by improved mitochondrial ATP production in primary afferent sensory axons and overall inhibition of the development of neuropathic pain. These data identify for the first time mitochondrial A3AR and indicate that activation of A3AR protects mitochondrial function in primary afferent sensory axons against chemotherapy-induced neurotoxicity. Repurposing A3AR agonists that are already in clinical trials as anticancer agents as adjunct to chemotherapeutics will address a major unmet medical need for which there are no FDA-approved drugs.

Is there a role for capsaicin in cancer pain management?

PURPOSE OF REVIEW

Advances in oncological therapies have resulted in an increase in the number of patients living with and beyond cancer. The personal and societal impact of chronic pain in the survivor population represents an area of significant unmet need. Capsaicin (a TRPV1 agonist) may provide analgesia with limited systemic side effects. This review looks to summarise the most recent evidence regarding the use of capsaicin in the management of cancer pain.

RECENT FINDINGS

Various international guidelines have recently endorsed the use of high concentration capsaicin patches in the treatment of chronic painful chemotherapy induced peripheral neuropathy. Numerous studies support the use of capsaicin in the treatment of peripheral neuropathic pain. This promising data is predominantly yielded from pain secondary to herpes zoster and diabetic neuropathy, with an expanding but small evidence base for its utility in other neuropathic pains. Emerging data suggests that treatments are better tolerated and provide analgesia more rapidly when compared with systemic treatments.

SUMMARY

Whilst randomised controlled trial data in the treatment of cancer pain are lacking, recent large cohort studies, and international guidelines, support the use of high concentration capsaicin patches in a wide variety of neuropathic pain secondary to cancer treatments.

Neurodegenerative disease pathways are perturbed in patients with cancer who self-report cognitive changes and anxiety: A pathway impact analysis

BACKGROUND

Cancer-related cognitive impairment (CRCI) and anxiety co-occur in patients with cancer. Little is known about mechanisms for the co-occurrence of these two symptoms. The purposes of this secondary analysis were to evaluate for perturbed pathways associated with the co-occurrence of self-reported CRCI and anxiety in patients with low versus high levels of these two symptoms and to identify potential mechanisms for the co-occurrence of CRCI and anxiety using biological processes common across any perturbed neurodegenerative disease pathways.

METHODS

Patients completed the Attentional Function Index and the Spielberger State-Trait Anxiety Inventory six times over two cycles of chemotherapy. Based on findings from a previous latent profile analysis, patients were grouped into none versus both high levels of these symptoms. Gene expression was quantified, and pathway impact analyses were performed. Signaling pathways for evaluation were defined with the Kyoto Encyclopedia of Genes and Genomes database.

RESULTS

A total of 451 patients had data available for analysis. Approximately 85.0% of patients were in the none class and 15.0% were in the both high class. Pathway impact analyses identified five perturbed pathways related to neurodegenerative diseases (i.e., amyotrophic lateral sclerosis, Huntington disease, Parkinson disease, prion disease, and pathways of neurodegeneration-multiple diseases). Apoptosis, mitochondrial dysfunction, oxidative stress, and endoplasmic reticulum stress were common biological processes across these pathways.

CONCLUSIONS

This study is the first to describe perturbations in neurodegenerative disease pathways associated with CRCI and anxiety in patients receiving chemotherapy. These findings provide new insights into potential targets for the development of mechanistically based interventions.

Efficacy of cryotherapy in the prevention of chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis

PURPOSE

The study investigates cryotherapy's efficacy in mitigating Chemotherapy-induced peripheral neuropathy (CIPN), an adverse effect of chemotherapy that often leads to dosage reduction or treatment discontinuation.

METHOD

The study was registered with PROSPERO (CRD42023428936). A literature search was conducted using the PubMed, Embase, and Cochrane Library databases. Randomized and nonrandomized controlled trials that investigated the effects of cryotherapy on CIPN were included for systematic review and meta-analysis. The primary outcome for prevention was the incidence of CIPN.

RESULTS

We identified 17 trials involving 2,851 patients. In total, 11 trials compared the incidence of CIPN between cryotherapy and control groups. Significant differences in the incidence of CIPN at the midpoint and end of chemotherapy were observed, with risk ratios (RRs) of 0.23 (95% confidence interval [CI] = 0.13 to 0.43) and 0.54 (95% CI = 0.33 to 0.88), respectively. Cryotherapy also significantly reduced the incidence of sensory CIPN, with an RR of 0.67 (95% CI = 0.49 to 0.92). Additionally, cryotherapy demonstrated a significant reduction in the incidence of CIPN in patients with gynecological cancers (RR = 0.24, 95% CI = 0.14 to 0.41). Significantly favorable global quality of life scores following chemotherapy (standardized mean difference = 1.43; 95% CI = 0.50 to 2.36) and relieved neuropathic symptoms were found with cryotherapy.

CONCLUSIONS

Cryotherapy demonstrates a pronounced preventive effect against the development of CIPN, providing substantial symptomatic relief and quality of life improvements for patients undergoing chemotherapy. The administration of cryotherapy through the use of frozen gloves and socks, or continuous-flow cooling systems, optimally initiated 15 min prior to and concluded 15 min following chemotherapy, is recommended for achieving maximum therapeutic efficacy.

Trajectories and influencing factors of social anxiety in postoperative breast cancer patients

BACKGROUND

Social anxiety among postoperative breast cancer patients is a prevalent concern, with its intensity fluctuating throughout the course of treatment. The study aims to describe the trajectory of social anxiety in postoperative breast cancer patients, explore the influencing factors, and provide theoretical support for the construction of future intervention programs.

METHODS

This study was conducted from June 2022 to January 2023, encompassing 213 breast cancer patients from three first-class hospitals in China. Data collection occurred at four distinct time points. A growth mixture model was employed to identify latent categories representing the trajectories of social anxiety changes among patients. A multiple regression analysis was utilized to explore predictive factors associated with different latent trajectory categories.

RESULTS

The trajectory of social anxiety changes in postoperative breast cancer patients includes five potential categories: maintaining mild social anxiety group, changing from mild to moderate social anxiety group, maintaining moderate social anxiety group, changing from moderate to severe social anxiety group, and maintaining severe social anxiety group. Cluster analysis results indicated three types: positive, negative, and low. Logistic regression analysis revealed that younger age, spouses concerned about postoperative appearance, chemotherapy with taxol-based drugs, opting for modified radical surgery or radical mastectomy surgical approaches, and breast cancer patients with negative rumination were factors that influenced patients' social anxiety (P < 0.05).

CONCLUSION

The trajectory of social anxiety in postoperative breast cancer patients comprises five potential categories. In clinical practice, it is essential to strengthen the management of high-risk populations susceptible to experiencing social anxiety emotions, including younger age, spouses concerned about postoperative appearance, chemotherapy with taxol-based drugs, opting for modified radical surgery or radical mastectomy surgical approaches, and breast cancer patients with negative rumination.

Protein Arginine Methyltransferase 5 Contributes to Paclitaxel-Induced Neuropathic Pain by Activating Transient Receptor Potential Vanilloid 1 Epigenetic Modification in Dorsal Root Ganglion

BACKGROUND

Paclitaxel (PTX), which is a first-line chemotherapy drug used to treat various types of cancers, exhibits peripheral neuropathy as a common side effect that is difficult to treat. Protein arginine methyltransferase 5 (PRMT 5) is a key regulator of the chemotherapy response, as chemotherapy drugs induce PRMT5 expression. However, little is known about the PRMT5-mediated epigenetic mechanisms involved in PTX-induced neuropathic allodynia.

METHODS

Sprague-Dawley rats were intraperitoneally given PTX to induce neuropathic pain. Biochemical analyses were conducted to measure the protein expression levels in the dorsal root ganglion (DRG) of the animals. The von Frey test and hot plate test were used to evaluate nociceptive behaviors.

RESULTS

PTX increased the PRMT5 (mean difference [MD]: 0.68, 95% confidence interval [CI], 0.88-0.48; P < .001 for vehicle)-mediated deposition of histone H3R2 dimethyl symmetric (H3R2me2s) at the transient receptor potential vanilloid 1 ( Trpv1 ) promoter in the DRG. PRMT5-induced H3R2me2s recruited WD repeat domain 5 (WDR5) to increase trimethylation of lysine 4 on histone H3 (H3K4me3) at Trpv1 promoters, thus resulting in TRPV1 transcriptional activation (MD: 0.65, 95% CI, 0.82-0.49; P < .001 for vehicle) in DRG in PTX-induced neuropathic pain. Moreover, PTX increased the activity of NADPH oxidase 4 (NOX4) (MD: 0.66, 95% CI, 0.81-0.51; P < .001 for vehicle), PRMT5-induced H3R2me2s, and WDR5-mediated H3K4me3 in the DRG in PTX-induced neuropathic pain. Pharmacological antagonism and the selective knockdown of PRMT5 in DRG neurons completely blocked PRMT5-mediated H3R2me2s, WDR5-mediated H3K4me3, or TRPV1 expression and neuropathic pain development after PTX injection. Remarkably, NOX4 inhibition not only attenuated allodynia behavior and reversed the above-mentioned signaling but also reversed NOX4 upregulation via PTX.

CONCLUSIONS

Thus, the NOX4/PRMT5-associated epigenetic mechanism in DRG has a dominant function in the transcriptional activation of TRPV1 in PTX-induced neuropathic pain.

Neurotoxicity induced by taxane-derived drugs: analysis of the FAERS database 2017-2021

OBJECTIVES

Taxane-related neurotoxicity is a frequent clinical problem but lacks postmarketing data regarding neurological disorders. This study aimed to evaluate the potential association between neurological adverse events and several taxanederived drugs via the Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

Disproportionality analysis was applied to data mining of the suspected cases of neurological disorders after using different taxanes based on the FAERS data from January 2017 and December 2021. We also investigated the times to onset, fatality, and hospitalization proportions of taxanerelated neurotoxicity.

RESULTS

In total, 3,940 cases were screened out, which were more prevalent in elderly patients and females. Peripheral neuropathy was a common adverse event among all taxanes with relatively strong association. Generally, the median time to neurological adverse effect onset was 27 days (interquartile range, 11.0 ~ 78.0 days) following taxane regimens, and the majority of cases were detected within the first 30 days. Among cases of neurological adverse events treated with taxane, the fatality and hospitalization proportions were 6.13% and 28.63%, respectively.

CONCLUSION

By analyzing the FAERS data, we provided a detailed profile of neurotoxicity and different taxanes in detail in terms of clinical characteristics, time to onset, and patient outcomes.

Big Data in Oncology Nursing Research: State of the Science

OBJECTIVE

To review the state of oncology nursing science as it pertains to big data. The authors aim to define and characterize big data, describe key considerations for accessing and analyzing big data, provide examples of analyses of big data in oncology nursing science, and highlight ethical considerations related to the collection and analysis of big data.

DATA SOURCES

Peer-reviewed articles published by investigators specializing in oncology, nursing, and related disciplines.

CONCLUSION

Big data is defined as data that are high in volume, velocity, and variety. To date, oncology nurse scientists have used big data to predict patient outcomes from clinician notes, identify distinct symptom phenotypes, and identify predictors of chemotherapy toxicity, among other applications. Although the emergence of big data and advances in computational methods provide new and exciting opportunities to advance oncology nursing science, several challenges are associated with accessing and using big data. Data security, research participant privacy, and the underrepresentation of minoritized individuals in big data are important concerns.

IMPLICATIONS FOR NURSING PRACTICE

With their unique focus on the interplay between the whole person, the environment, and health, nurses bring an indispensable perspective to the interpretation and application of big data research findings. Given the increasing ubiquity of passive data collection, all nurses should be taught the definition, characteristics, applications, and limitations of big data. Nurses who are trained in big data and advanced computational methods will be poised to contribute to guidelines and policies that preserve the rights of human research participants.

Emerging roles of toll-like receptor 4 in chemotherapy-induced neurotoxicity

Chemotherapy-induced neurotoxicity is one of the most prevalent side effects in cancer patients and survivors. Cognitive decline and peripheral neuropathy are the most common chemotherapy-induced neurotoxic symptoms. These symptoms lead not only to the limiting of the dose of chemotherapy given to cancer patients, but also have an impact on the quality of life of cancer survivors. Although the exact mechanisms involved in chemotherapy-induced neurotoxicity are still unclear, neuroinflammation is widely regarded as being one of the major causes involved in chemotherapy-induced neurotoxicity. It is known that Toll-like receptor 4 (TLR4) plays a critical role in the inflammatory process, and it has been recently reported that it is associated with chemotherapy-induced neurotoxicity. In this review, we summarize and discuss all available evidence regarding the activation of the TLR4 signaling pathway in various models of chemotherapy-induced neurotoxicity. This review also emphasizes the evidence pertinent to TLR4 inhibition on chemotherapy-induced neurotoxicity in rodent studies. Understanding the role of the TLR4 signaling pathway behind chemotherapy-induced neurotoxicity is crucial for improving treatments and ensuring the long-term survival of cancer patients.

Cellular Pathogenesis of Chemotherapy-Induced Peripheral Neuropathy: Insights From Drosophila and Human-Engineered Skin Models

Chemotherapy-induced peripheral neuropathy (CIPN) is a highly prevalent and complex condition arising from chemotherapy cancer treatments. Currently, there are no treatment or prevention options in the clinic. CIPN accompanies pain-related sensory functions starting from the hands and feet. Studies focusing on neurons in vitro and in vivo models significantly advanced our understanding of CIPN pathological mechanisms. However, given the direct toxicity shown in both neurons and non-neuronal cells, effective in vivo or in vitro models that allow the investigation of neurons in their local environment are required. No single model can provide a complete solution for the required investigation, therefore, utilizing a multi-model approach would allow complementary advantages of different models and robustly validate findings before further translation. This review aims first to summarize approaches and insights from CIPN in vivo models utilizing small model organisms. We will focus on Drosophila melanogaster CIPN models that are genetically amenable and accessible to study neuronal interactions with the local environment in vivo. Second, we will discuss how these findings could be tested in physiologically relevant vertebrate models. We will focus on in vitro approaches using human cells and summarize the current understanding of engineering approaches that may allow the investigation of pathological changes in neurons and the skin environment.

Role of Cannabidiol and Tetrahydrocannabivarin on Paclitaxel-induced neuropathic pain in rodents

The purpose of this study was to evaluate if phytocannabinoids, synthetic cannabidiol (CBD), and tetrahydrocannabivarin (THCV), and their combination, could protect mice from Paclitaxel-induced peripheral neuropathy (PIPN). Six groups of C57BL/6J mice (n = 6) were used in this study. The mice were given paclitaxel (PTX) (8 mg/kg/day, i.p.) on days 1, 3, 5, and 7 to induce neuropathy. Mice were evaluated for behavioral parameters, and dorsal root ganglions (DRG) were collected from the animals and subjected to RNA sequencing and westernblot analysis at the end of the study. On cultured DRGs derived from adult male rats, immunocytochemistry and mitochondrial functional assays were also performed. When compared to individual treatments, the combination of CBD and THCV improved thermal and mechanical neurobehavioral symptoms in mice by twofold. Targets for CBD and THCV therapy were identified by KEGG (RNA sequencing). PTX reduced the expression of p-AMPK, SIRT1, NRF2, HO1, SOD2, and catalase while increasing the expression of PI3K, p-AKT, p-P38 MAP kinase, BAX, TGF-β, NLRP3 inflammasome, and caspase 3 in DRG homogenates of mice. Combination therapy outperformed monotherapy in reversing these protein expressions. The addition of CBD and THCV to DRG primary cultures reduced mitochondrial superoxides while increasing mitochondrial membrane potentials. WAY100135 and rimonabant altered the neuroprotective effects of CBD and THCV respectively by blocking 5-HT1A and CB1 receptors in mice and DRG primary cultures. The entourage effect of CBD and THCV against PIPN appears to protect neurons in mice via 5HT1A and CB1 receptors respectively.

Longitudinal RNA Sequencing of Skin and DRG Neurons in Mice with Paclitaxel-Induced Peripheral Neuropathy

Paclitaxel-induced peripheral neuropathy is a condition of nerve degeneration induced by chemotherapy, which afflicts up to 70% of treated patients. Therapeutic interventions are unavailable due to an incomplete understanding of the underlying mechanisms. We previously discovered that major physiological changes in the skin underlie paclitaxel-induced peripheral neuropathy in zebrafish and rodents. The precise molecular mechanisms are only incompletely understood. For instance, paclitaxel induces the upregulation of MMP-13, which, when inhibited, prevents axon degeneration. To better understand other gene regulatory changes induced by paclitaxel, we induced peripheral neuropathy in mice following intraperitoneal injection either with vehicle or paclitaxel every other day four times total. Skin and dorsal root ganglion neurons were collected based on distinct behavioural responses categorised as “pain onset” (d4), “maximal pain” (d7), “beginning of pain resolution” (d11), and “recovery phase” (d23) for comparative longitudinal RNA sequencing. The generated datasets validate previous discoveries and reveal additional gene expression changes that warrant further validation with the goal to aid in the development of drugs that prevent or reverse paclitaxel-induced peripheral neuropathy.

A Multimodal Approach to Discover Biomarkers for Taxane-Induced Peripheral Neuropathy (TIPN): A Study Protocol

Introduction: Taxanes are a class of chemotherapeutics commonly used to treat various solid tumors, including breast and ovarian cancers. Taxane-induced peripheral neuropathy (TIPN) occurs in up to 70% of patients, impacting quality of life both during and after treatment. TIPN typically manifests as tingling and numbness in the hands and feet and can cause irreversible loss of function of peripheral nerves. TIPN can be dose-limiting, potentially impacting clinical outcomes. The mechanisms underlying TIPN are poorly understood. As such, there are limited treatment options and no tools to provide early detection of those who will develop TIPN. Although some patients may have a genetic predisposition, genetic biomarkers have been inconsistent in predicting chemotherapy-induced peripheral neuropathy (CIPN). Moreover, other molecular markers (eg, metabolites, mRNA, miRNA, proteins) may be informative for predicting CIPN, but remain largely unexplored. We anticipate that combinations of multiple biomarkers will be required to consistently predict those who will develop TIPN. Methods: To address this clinical gap of identifying patients at risk of TIPN, we initiated the Genetics and Inflammatory Markers for CIPN (GENIE) study. This longitudinal multicenter observational study uses a novel, multimodal approach to evaluate genomic variation, metabolites, DNA methylation, gene expression, and circulating cytokines/chemokines prior to, during, and after taxane treatment in 400 patients with breast cancer. Molecular and patient reported data will be collected prior to, during, and after taxane therapy. Multi-modal data will be used to develop a set of comprehensive predictive biomarker signatures of TIPN. Conclusion: The goal of this study is to enable early detection of patients at risk of developing TIPN, provide a tool to modify taxane treatment to minimize morbidity from TIPN, and improved patient quality of life. Here we provide a brief review of the current state of research into CIPN and TIPN and introduce the GENIE study design.

Quality Control Mechanisms of Mitochondria: Another Important Target for Treatment of Peripheral Neuropathy

Mitochondria provide energy for various cellular activities and are involved in the regulating of several physiological and pathological processes. Mitochondria constitute a dynamic network regulated by numerous quality control mechanisms; for example, division is necessary for mitochondria to develop, and fusion dilutes toxins produced by the mitochondria. Mitophagy removes damaged mitochondria. The etiologies of peripheral neuropathy include congenital and acquired diseases, and the pathogenesis varies; however, oxidative stress caused by mitochondrial damage is the accepted pathogenesis of peripheral neuropathy. Regulation and control of mitochondrial quality might point the way toward potential treatments for peripheral neuropathy. This article will review mitochondrial quality control mechanisms, their involvement in peripheral nerve diseases, and their potential therapeutic role.

PEA-OXA Mitigates Oxaliplatin-Induced Painful Neuropathy through NF-κB/Nrf-2 Axis

Chemotherapy-induced neuropathy is a common, dose-dependent adverse effect of several antineoplastics, such as oxaliplatin (L-OHP). The aim of the present work was to evaluate the potential beneficial effects of 2-pentadecyl-2-oxazoline (PEA-OXA) in a murine model of oxaliplatin-induced peripheral neuropathy (OIPN). OIPN was induced by an intraperitoneally injection of L-OHP in rats on five consecutive days (D0-4) for a final cumulative dose of 10 mg/kg. PEA-OXA and ultramicronized palmitoylethanolamide (PEAum), both 10 mg/kg, were given orally 15-20 min prior (L-OHP) and sacrifice was made on day 25. Our results demonstrated that PEA-OXA, more than PEAum, reduced the development of hypersensitivity in rats; this was associated with the reduction in hyperactivation of glia cells and the increased production of proinflammatory cytokines in the dorsal horn of the spinal cord, accompanied by an upregulation of neurotrophic factors in the dorsal root ganglia (DRG). Moreover, we showed that PEA-OXA reduced L-OHP damage via a reduction in NF-κB pathway activation and a modulation of Nrf-2 pathways. Our findings identify PEA-OXA as a therapeutic target in chemotherapy-induced painful neuropathy, through the biomolecular signaling NF-κB/Nrf-2 axis, thanks to its abilities to counteract L-OHP damage. Therefore, we can consider PEA-OXA as a promising adjunct to chemotherapy to reduce chronic pain in patients.

Occurrence of tinnitus and peripheral sensory neuropathy in women during chemotherapy treatment of breast cancer

Objective: To analyze the occurrence of tinnitus and peripheral sensory neuropathy in women during breast cancer chemotherapy. Methods: This is a retrospective analytical study with a quantitative approach, performed in medical records of an oncology outpatient service between February 2014 and February 2015, using the toxicities scores of Common Terminology Criteria for Adverse Events (CTCAE). Results: Considering 181 patients with breast cancer who met the inclusion criteria, 49.2% reported tinnitus at some point of the treatment, while 65.1% peripheral sensory neuropathy. In both conditions, the predominant severity score was grade 1, with frequencies of 23.8% and 33.1%, respectively. A significant, positive and weak correlation was observed between the severity of tinnitus and peripheral sensory neuropathy (ρ = 0.325 and p = 0.001), as well as very weak between the number of complete cycles of chemotherapy and tinnitus (ρ = 0.195 and p = 0.009) and neuropathy peripheral sensory (ρ = 0.237 and p = 0.002). Conclusions: Tinnitus and peripheral sensory neuropathy were frequent toxicities during chemotherapy treatment of breast cancer, and both manifested with low severity/functional impact in most participants.

Heart rate variability and vibration perception threshold to assess chemotherapy-induced neuropathy in women with breast cancer - a systematic review

BACKGROUND

It is well known that breast cancer (BC) patients often suffer from chemotherapy-induced peripheral neuropathy (CIPN). However, it is not always recognized that they have higher risk of falling, dizziness and other signs of dysfunctional autonomous nervous system. We performed a systematic review of the literature on vibration perception threshold (VPT) and heart rate variability (HRV) as methods to objectively assess (CIPN) in BC-patients. Could VPT and HRV describe coexisting sensory and autonomic nerve damage?

MATERIALS AND METHODS

PubMed was searched in September 2019. The included studies had to address HRV and/or VPT in BC-patients who received chemotherapy.

RESULTS

Seven studies assessed VPT and six studies assessed HRV in BC-patients. Studies showed lowered perception of vibrations after chemotherapy reflected in higher VPT and no changes in HRV after taxane-based chemotherapy. No studies evaluated VPT and HRV at the same time.

CONCLUSION

The results were limited by short follow-up, small sample sizes, and different chemotherapy regimens which makes generalizability problematic. A standard assessment method of CIPN is still missing and further research is needed to evaluate if VPT and HRV could contribute to an objective assessment of CIPN. With higher survival rates for BC-patients autonomous and sensory nerve damage will be an increasing task. However, our literature review showed that no one have focused on the combination of autonomous and sensory affection measured by the simple methods VPT and HRV. Therefore, we encourage the development of international guidelines for the objective measure of nerve damage in BC-patients.

Emerging pharmacological strategies for the management of chemotherapy-induced peripheral neurotoxicity (CIPN), based on novel CIPN mechanisms

INTRODUCTION

Based on results of available clinical trials, the treatment and prevention of chemotherapy-induced peripheral neurotoxicity (CIPN) largely remains an unmet clinical need. However, new approaches have emerged in the last few years, attempting to modify the natural history of acute and late CIPN effects through a better knowledge of the pathogenic process on the molecular level.

AREAS COVERED

Clinical results of recently published (last 5 years) or ongoing emerging therapeutic/preventive pharmacological approaches based on novel CIPN mechanisms have been identified from Pubmed and ClinicalTrials.gov. Results are reviewed and discussed, in order to assess the trend of new clinical studies but also to infer the role novel approaches may have in the future.

EXPERT OPINION

The large heterogeneity of disease-causing mechanisms prevents researchers from identifying a reliable approach to effectively and safely treat or prevent CIPN. Understanding of novel pathophysiologic processes is leading the way to novel therapies, which, through targeting the sphingosine 1-phosphate receptor or pharmacologically inhibiting axonal degeneration might achieve in the future both treatment and prevention of CIPN. Toward this end, a multi-targeting approach, combining drugs to target different CIPN pathomechanisms seems to be a rational approach that warrants testing.

An investigation into socio-demographic-, health-, and cancer-related factors associated with cortisol and C-reactive protein levels in breast cancer survivors: a longitudinal study

BACKGROUND

Breast cancer survivors (BCS) may exhibit dysregulated patterns of cortisol and C-reactive protein (CRP). The aims of this study were to describe BCS' cortisol and CRP levels over a 1-year period after treatment, and assess how levels relate to socio-demographic- (age, education level, marital status), health- (body mass index [BMI] category, menopausal status), and cancer-related factors (cancer stage, chemotherapy exposure, time since diagnosis).

METHODS

Participants (N = 201) provided data at 3 months post-treatment (T1) and again 3, 6, 9, and 12 months later (T2-T5). At T1, participants completed self-report questionnaires and had their weight and height measured by a trained technician. At T1-T5, they provided five saliva samples at awakening, 30 min after awakening, 2:00 pm, 4:00 pm, and before bedtime on two nonconsecutive days to measure diurnal cortisol, and provided capillary whole blood to measure CRP. Data were analyzed using repeated-measure analyses of variance (ANOVAs) and mixed-design ANOVAs.

RESULTS

Diurnal cortisol and CRP levels fluctuated over time. In univariate models, older age and post-menopausal status were associated with higher cortisol and CRP levels, higher cancer stage and chemotherapy were associated with lower cortisol levels, and higher BMI category was associated with higher CRP levels. In adjusted models, age was no longer associated with CRP levels and shorter time since diagnosis was significantly associated with higher CRP levels.

CONCLUSIONS

Socio-demographic-, health-, and cancer-related factors may help identify BCS at risk of physiological dysregulation who need intervention. Identifying modifiable factors associated with cortisol and CRP will inform cancer care interventions.

Alterations in Patterns of Gene Expression and Perturbed Pathways in the Gut-Brain Axis Are Associated With Chemotherapy-Induced Nausea

CONTEXT

Despite current advances in antiemetic treatments, approximately 50% of oncology patients experience chemotherapy-induced nausea (CIN).

OBJECTIVES

The purpose of this study was to evaluate for differentially expressed genes and perturbed pathways associated with the gut-brain axis (GBA) across two independent samples of oncology patients who did and did not experience CIN.

METHODS

Oncology patients (n = 735) completed study questionnaires in the week before their second or third cycle of chemotherapy. CIN occurrence was assessed using the Memorial Symptom Assessment Scale. Gene expression analyses were performed in two independent samples using ribonucleic acid sequencing (Sample 1, n = 357) and microarray (Sample 2, n = 352) methodologies. Fisher's combined probability method was used to determine genes that were differentially expressed and pathways that were perturbed between the two nausea groups across both samples.

RESULTS

CIN was reported by 63.6% of the patients in Sample 1 and 48.9% of the patients in Sample 2. Across the two samples, 703 genes were differentially expressed, and 37 pathways were found to be perturbed between the two CIN groups. We identified nine perturbed pathways that are involved in mechanisms associated with alterations in the GBA (i.e., mucosal inflammation, disruption of gut microbiome).

CONCLUSION

Persistent CIN remains a significant clinical problem. Our study is the first to identify novel GBA-related pathways associated with the occurrence of CIN. Our findings warrant confirmation and suggest directions for future clinical studies to decrease CIN occurrence.

Signaling pathways and gene co-expression modules associated with cytoskeleton and axon morphology in breast cancer survivors with chronic paclitaxel-induced peripheral neuropathy

Background

The major dose-limiting toxicity of paclitaxel, one of the most commonly used drugs to treat breast cancer, is peripheral neuropathy (paclitaxel-induced peripheral neuropathy). Paclitaxel-induced peripheral neuropathy, which persists into survivorship, has a negative impact on patient’s mood, functional status, and quality of life. Currently, no interventions are available to treat paclitaxel-induced peripheral neuropathy. A critical barrier to the development of efficacious interventions is the lack of understanding of the mechanisms that underlie paclitaxel-induced peripheral neuropathy. While data from preclinical studies suggest that disrupting cytoskeleton- and axon morphology-related processes are a potential mechanism for paclitaxel-induced peripheral neuropathy, clinical evidence is limited. The purpose of this study in breast cancer survivors was to evaluate whether differential gene expression and co-expression patterns in these pathways are associated with paclitaxel-induced peripheral neuropathy.

Methods

Signaling pathways and gene co-expression modules associated with cytoskeleton and axon morphology were identified between survivors who received paclitaxel and did (n = 25) or did not (n = 25) develop paclitaxel-induced peripheral neuropathy.

Results

Pathway impact analysis identified four significantly perturbed cytoskeleton- and axon morphology-related signaling pathways. Weighted gene co-expression network analysis identified three co-expression modules. One module was associated with paclitaxel-induced peripheral neuropathy group membership. Functional analysis found that this module was associated with four signaling pathways and two ontology annotations related to cytoskeleton and axon morphology.

Conclusions

This study, which is the first to apply systems biology approaches using circulating whole blood RNA-seq data in a sample of breast cancer survivors with and without chronic paclitaxel-induced peripheral neuropathy, provides molecular evidence that cytoskeleton- and axon morphology-related mechanisms identified in preclinical models of various types of neuropathic pain including chemotherapy-induced peripheral neuropathy are found in breast cancer survivors and suggests pathways and a module of genes for validation and as potential therapeutic targets.

Chemotherapy-induced peripheral neuropathy: where are we now?

Chemotherapy-induced peripheral neuropathy (CIPN) is a major challenge, with increasing impact as oncological treatments, using potentially neurotoxic chemotherapy, improve cancer cure and survival. Acute CIPN occurs during chemotherapy, sometimes requiring dose reduction or cessation, impacting on survival. Around 30% of patients will still have CIPN a year, or more, after finishing chemotherapy. Accurate assessment is essential to improve knowledge around prevalence and incidence of CIPN. Consensus is needed to standardize assessment and diagnosis, with use of well-validated tools, such as the EORTC-CIPN 20. Detailed phenotyping of the clinical syndrome moves toward a precision medicine approach, to individualize treatment. Understanding significant risk factors and pre-existing vulnerability may be used to improve strategies for CIPN prevention, or to use targeted treatment for established CIPN. No preventive therapies have shown significant clinical efficacy, although there are promising novel agents such as histone deacetylase 6 (HDAC6) inhibitors, currently in early phase clinical trials for cancer treatment. Drug repurposing, eg, metformin, may offer an alternative therapeutic avenue. Established treatment for painful CIPN is limited. Following recommendations for general neuropathic pain is logical, but evidence for agents such as gabapentinoids and amitriptyline is weak. The only agent currently recommended by the American Society of Clinical Oncology is duloxetine. Mechanisms are complex with changes in ion channels (sodium, potassium, and calcium), transient receptor potential channels, mitochondrial dysfunction, and immune cell interactions. Improved understanding is essential to advance CIPN management. On a positive note, there are many potential sites for modulation, with novel analgesic approaches.

Recent advances in understanding chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common cause of pain and poor quality of life for those undergoing treatment for cancer and those surviving cancer. Many advances have been made in the pre-clinical science; despite this, these findings have not been translated into novel preventative measures and treatments for CIPN. This review aims to give an update on the pre-clinical science, preventative measures, assessment and treatment of CIPN.

The Role of Oxidative Stress in Peripheral Neuropathy

Peripheral neuropathy (PN) is a common disease affecting about 5% of the general population after the age of 50. Causes of PN are numerous and include genetic, diabetes, alcohol, vitamin deficiencies, and gluten sensitivity among others. This systematic review aimed to study the association between oxidative stress and PN in an attempt to better understand PN pathogenesis. A computer-based, systematic search was conducted on the PubMed database, and ensuing data from included articles was analyzed and discussed in this review. Sixty-nine papers were eligible and were used for this review. Peripheral neuropathy is associated with an increase of reactive oxygen species and a decrease in endogenous antioxidants. Genetic predisposition to oxidative damage may be a factor. Antioxidant treatment is promising regarding treatment. Though further research is necessary to better understand the underlying mechanism, it is evident that oxidative stress is implicated in the pathogenesis of - or is at least systematically present in - PN.

Effects of hub genes on the clinicopathological and prognostic features of lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a common malignancy; however, the majority of its underlying molecular mechanisms remain unknown. In the present study, weighted gene co-expression network analysis was applied to construct gene co-expression networks for the GSE19804 dataset, in order to screen hub genes associated with the pathogenesis of LUAD. In addition, with the aid of the Database for Annotation, Visualization and Integrated Discovery, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes, pathway enrichment analyses were performed on the genes in the selected module. Using the GSE40791 dataset and The Cancer Genome Atlas database, the hub genes were identified. It was discovered that the turquoise module was the most significant module associated with the tumor stage of LUAD. After performing functional enrichment analyses, it was indicated that the turquoise module was mainly enriched in signal transduction. Additionally, at the transcriptional and translational level, nine hub genes were identified and validated: Carbonic anhydrase 4 (CA4), platelet and endothelial cell adhesion molecule 1 (PECAM1), DnaJ member B4 (DNAJB4), advanced glycosylation end-product specific receptor (AGER), GTPase, IMAP family member 6 (GIMAP6), chromosome 10 open reading frame 54 (C10orf54), dedicator of cytokinesis 4 (DOCK4), Golgi membrane protein 1 (GOLM1) and platelet activating factor acetylhydrolase 1b catalytic subunit 3 (PAFAH1B3). CA4, PECAM1, DNAJB4, AGER, GIMAP6, C10orf54 and DOCK4 were expressed at lower levels in the tumor samples, whereas GOLM1 and PAFAH1B3 were highly expressed in tumor samples. In addition, all hub genes were associated with prognosis. In conclusion, one module and nine genes were recognized to be associated with the tumor stage of LUAD. These findings may enhance the understanding of the progression and prognosis of LUAD.

Differential methylation and expression of genes in the hypoxia-inducible factor 1 signaling pathway are associated with paclitaxel-induced peripheral neuropathy in breast cancer survivors and with preclinical models of chemotherapy-induced neuropathic pain

BACKGROUND

Paclitaxel is an important chemotherapeutic agent for the treatment of breast cancer. Paclitaxel-induced peripheral neuropathy (PIPN) is a major dose-limiting toxicity that can persist into survivorship. While not all survivors develop PIPN, for those who do, it has a substantial negative impact on their functional status and quality of life. No interventions are available to treat PIPN. In our previous studies, we identified that the HIF-1 signaling pathway (H1SP) was perturbed between breast cancer survivors with and without PIPN. Preclinical studies suggest that the H1SP is involved in the development of bortezomib-induced and diabetic peripheral neuropathy, and sciatic nerve injury. The purpose of this study was to identify H1SP genes that have both differential methylation and differential gene expression between breast cancer survivors with and without PIPN.

METHODS

A multi-staged integrated analysis was performed. In peripheral blood, methylation was assayed using microarray and gene expression was assayed using RNA-seq. Candidate genes in the H1SP having both differentially methylation and differential expression were identified between survivors who received paclitaxel and did (n = 25) and did not (n = 25) develop PIPN. Then, candidate genes were evaluated for differential methylation and differential expression in public data sets of preclinical models of PIPN and sciatic nerve injury.

RESULTS

Eight candidate genes were identified as both differential methylation and differential expression in survivors. Of the eight homologs identified, one was found to be differential expression in both PIPN and "normal" mice dorsal root ganglia; three were differential methylation in sciatic nerve injury versus sham rats in both pre-frontal cortex and T-cells; and two were differential methylation in sciatic nerve injury versus sham rats in the pre-frontal cortex.

CONCLUSIONS

This study is the first to evaluate for methylation in cancer survivors with chronic PIPN. The findings provide evidence that the expression of H1SP genes associated with chronic PIPN in cancer survivors may be regulated by epigenetic mechanisms and suggests genes for validation as potential therapeutic targets.

A Biopsychosocial Model of Chronic Pain for Older Adults

Population

Comprehensive evaluation of chronic pain in older adults is multifaceted.

Objective and Methods

Research on chronic pain in older adults needs to be guided by sound conceptual models. The purpose of this paper is to describe an adaptation of the Biopsychosocial Model (BPS) of Chronic Pain for older adults. The extant literature was reviewed, and selected research findings that provide the empiric foundation for this adaptation of the BPS model of chronic pain are summarized. The paper concludes with a discussion of specific recommendations for how this adapted model can be used to guide future research.

Conclusions

This adaptation of the BPS model of chronic pain for older adults provides a comprehensive framework to guide future research in this vulnerable population.

Perturbations in neuroinflammatory pathways are associated with paclitaxel-induced peripheral neuropathy in breast cancer survivors

Paclitaxel is a common chemotherapy drug associated with the development of chronic paclitaxel-induced peripheral neuropathy (PIPN). PIPN is associated with neuroinflammatory mechanisms in pre-clinical studies. Here, we evaluated for differential gene expression (DGE) in peripheral blood between breast cancer survivors with and without PIPN and for neuroinflammatory (NI) related signaling pathways and whole-transcriptome profiles from other experiments. Pathway impact analysis identified 8 perturbed NI related pathways. Expression profile analysis found 15 experiments having similar whole-transcriptome profiles of DGE related to neuroinflammation and PIPN. These findings suggest that perturbations in pathways associated with neuroinflammation are found in cancer survivors with PIPN.

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Paclitaxel-induced peripheral neuropathy (PIPN) is associated with Paclitaxel treatment

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Differential gene expression was associated with PIPN in breast cancer survivors.

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Perturbations of neuroinflammatory-related pathways were identified between survivors.

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Transcriptome profile was similar to other pre-clinical and clinical studies.

Mitochondrial dysfunction in the pathogenesis of chemotherapy-induced peripheral neuropathy

Several first-line chemotherapeutic agents, including taxanes, platinum agents and proteasome inhibitors, are associated with the dose-limiting side effect of chemotherapy-induced peripheral neuropathy (CIPN). CIPN predominantly manifests as sensory symptoms, which are likely due to drug accumulation within peripheral nervous tissues rather than the central nervous system. No treatment is currently available to prevent or reverse CIPN. The causal mechanisms underlying CIPN are not yet fully understood. Mitochondrial dysfunction has emerged as a major factor contributing to the development and maintenance of CIPN. This chapter will provide an overview of both clinical and preclinical data supporting this hypothesis. We will review the studies reporting the nature of mitochondrial dysfunction evoked by chemotherapy in terms of changes in mitochondrial morphology, bioenergetics and reactive oxygen species (ROS) generation. Furthermore, we will discuss the in vivo effects of pharmacological interventions that counteract chemotherapy-evoked mitochondrial dysfunction and ameliorate pain-like behavior.

Mechanisms of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most frequent side effects caused by antineoplastic agents, with a prevalence from 19% to over 85%. Clinically, CIPN is a mostly sensory neuropathy that may be accompanied by motor and autonomic changes of varying intensity and duration. Due to its high prevalence among cancer patients, CIPN constitutes a major problem for both cancer patients and survivors as well as for their health care providers, especially because, at the moment, there is no single effective method of preventing CIPN; moreover, the possibilities of treating this syndrome are very limited. There are six main substance groups that cause damage to peripheral sensory, motor and autonomic neurons, which result in the development of CIPN: platinum-based antineoplastic agents, vinca alkaloids, epothilones (ixabepilone), taxanes, proteasome inhibitors (bortezomib) and immunomodulatory drugs (thalidomide). Among them, the most neurotoxic are platinum-based agents, taxanes, ixabepilone and thalidomide; other less neurotoxic but also commonly used drugs are bortezomib and vinca alkaloids. This paper reviews the clinical picture of CIPN and the neurotoxicity mechanisms of the most common antineoplastic agents. A better understanding of the risk factors and underlying mechanisms of CIPN is needed to develop effective preventive and therapeutic strategies.