Mechanisms Of Chemotherapy-induced Peripheral Neuropathy Research Articles

Role of HMGB1 in Chemotherapy-Induced Peripheral Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN), one of major dose-limiting side effects of first-line chemotherapeutic agents such as paclitaxel, oxaliplatin, vincristine, and bortezomib is resistant to most of existing medicines. The molecular mechanisms of CIPN have not been fully understood. High mobility group box 1 (HMGB1), a nuclear protein, is a damage-associated molecular pattern protein now considered to function as a pro-nociceptive mediator once released to the extracellular space. Most interestingly, HMGB1 plays a key role in the development of CIPN. Soluble thrombomodulin (TMα), known to degrade HMGB1 in a thrombin-dependent manner, prevents CIPN in rodents treated with paclitaxel, oxaliplatin, or vincristine and in patients with colorectal cancer undergoing oxaliplatin-based chemotherapy. In this review, we describe the role of HMGB1 and its upstream/downstream mechanisms in the development of CIPN and show drug candidates that inhibit the HMGB1 pathway, possibly useful for prevention of CIPN.

Role for Drug Transporters in Chemotherapy-Induced Peripheral Neuropathy.

Chemotherapy‐induced peripheral neuropathy (CIPN) is a common and dose‐limiting toxicity to widely used chemotherapeutics. Although the exact molecular mechanism of chemotherapy‐induced peripheral neuropathy remains elusive, there is consensus that it is caused by damage to the peripheral nervous system leading to sensory symptoms. Recently developed methodologies have provided evidence of expression of drug transporters in the peripheral nervous system. In this literature review, we explore the role for drug transporters in CIPN. First, we assessed the transport of chemotherapeutics that cause CIPN (taxanes, platins, vincristine, bortezomib, epothilones, and thalidomide). Second, we cross‐referenced the transporters implicated in genetic or functional studies with CIPN with their expression in the peripheral nervous system. Several drug transporters are involved in the transport of chemotherapeutics that cause peripheral neuropathy and particularly efflux transporters, such as ABCB1 and ABCC1, are expressed in the peripheral nervous system. Previous literature has linked genetic variants in efflux transporters to higher risk of peripheral neuropathy with the taxanes paclitaxel and docetaxel and the vinca alkaloid vincristine. We propose that this might be due to accumulation of the chemotherapeutics in the peripheral nervous system due to reduced neuronal efflux capacity. Thus, concomitant administration of efflux transporter inhibitors may lead to higher risk of adverse events of drugs that cause CIPN. This might prove valuable in drug development where screening new drugs for neurotoxicity might also require drug transporter consideration. There are ongoing efforts targeting drug transporters in the peripheral nervous system to reduce intraneuronal concentrations of chemotherapeutics that cause CIPN, which might ultimately protect against this dose‐limiting adverse event.

High mobility group box-1-toll-like receptor 4-phosphatidylinositol 3-kinase/protein kinase B-mediated generation of matrix metalloproteinase-9 in the dorsal root ganglion promotes chemotherapy-induced peripheral neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a significant side effect of chemotherapeutics. The mechanisms of CIPN remain substantially unidentified, although inflammation-induced peripheral sensitization has been indicated as an important factor. Here, we aimed to illustrate the role of the matrix metalloproteinase (MMP)-9-related signaling pathway in the process of CIPN. Oxaliplatin (L-OHP) was administered to mice to establish the CIPN model. Gelatin zymography was used to measure MMP-9/2 activities. Western blotting and immunohistochemistry were used to measure the expression of high-mobility group box-1 (HMGB-1), calcitonin gene-related peptide and ionized calcium-binding adapter molecule 1. Mechanical withdrawal was measured by von Frey hairs testing. Raw 264.7 cells and SH-SY5Y cells were cultured to investigate cell signaling in vitro. Here, we report that L-OHP-induced mechanical pain in mice with significant MMP-9/2 activation in dorsal root ganglion (DRG) neurons. MMP-9 inhibition or knockout alleviated the occurrence of CIPN directly. MMP-9/2 were released from macrophages and neurons in the DRG via the HMGB-1-toll-like receptor 4 (TLR4)-phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) axis, because MMP-9/2 activities could be reduced by macrophage scavengers or PI3Kγ knockout in CIPN mice. The in vitro data revealed that induced MMP-9 activity by recombinant HMGB-1 could be abolished by TLR4, PI3K or Akt inhibitors. Finally, it was shown that N-acetyl-cysteine (NAC) could reduce MMP-9/2 activities and attenuate CIPN effectively and safely. The HMGB-1-TLR4-PI3K/Akt-MMP-9 axis is involved in the crosstalk between macrophages and neurons in the pathological process of CIPN in mice. Direct inhibition of MMP-9 by NAC may be a potential therapeutic regimen for CIPN treatment.

A Comparative Review of Chemotherapy-Induced Peripheral Neuropathy in In Vivo and In Vitro Models.

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse effect caused by several classes of widely used anticancer therapeutics. Chemotherapy-induced peripheral neuropathy frequently leads to dose reduction or discontinuation of chemotherapy regimens, and CIPN symptoms can persist long after completion of chemotherapy and severely diminish the quality of life of patients. Differences in the clinical presentation of CIPN by widely diverse classifications of anticancer agents have spawned multiple mechanistic hypotheses that seek to explain the pathogenesis of CIPN. Despite its clinical relevance, common occurrence, and extensive investigation, the pathophysiology of CIPN remains unclear. Furthermore, there is no unequivocal gold standard for the prevention and treatment of CIPN. Herein, we review in vivo and in vitro models of CIPN with a focus on histopathological changes and morphological features aimed at understanding the pathophysiology of CIPN and identify gaps requiring deeper exploration. An elucidation of the underlying mechanisms of CIPN is imperative to identify potential targets and approaches for prevention and treatment.

Macrophage Toll-like Receptor 9 Contributes to Chemotherapy-Induced Neuropathic Pain in Male Mice

Chemotherapy-induced peripheral neuropathy (CIPN) remains a pressing clinical problem; however, our understanding of sexual dimorphism in CIPN remains unclear. Emerging studies indicate a sex-dimorphic role of Toll-like receptor 4 (TLR4) in driving neuropathic pain. In this study, we examined the role of TLR9 in CIPN induced by paclitaxel in WT and Tlr9 mutant mice of both sexes. Baseline pain sensitivity was not affected in either Tlr9 mutant male or female mice. Intraplantar and intrathecal injection of the TLR9 agonist ODN 1826 induced mechanical allodynia in both sexes of WT and Tlr4 KO mice but failed to do so in Tlr9 mutant mice. Moreover, Trpv1 KO or C-fiber blockade by resiniferatoxin failed to affect intraplantar ODN 1826-induced mechanical allodynia. Interestingly, the development of paclitaxel-evoked mechanical allodynia was attenuated by TLR9 antagonism or Tlr9 mutation only in male mice. Paclitaxel-induced CIPN caused macrophage infiltration to DRGs in both sexes, and this infiltration was not affected by Tlr9 mutation. Paclitaxel treatment also upregulated TNF and CXCL1 in macrophage cultures and DRG tissues in both sexes, but these changes were compromised by Tlr9 mutation in male animals. Intraplantar adoptive transfer of paclitaxel-activated macrophages evoked mechanical allodynia in both sexes, which was compromised by Tlr9 mutation or by treatment with TLR9 inhibitor only in male animals. Finally, TLR9 antagonism reduced paclitaxel-induced mechanical allodynia in female nude mice (T-cell and B-cell deficient). Together, these findings reveal sex-dimorphic macrophage TLR9 signaling in chemotherapy-induced neuropathic pain.SIGNIFICANCE STATEMENT Chemotherapy-induced peripheral neuropathy (CIPN) is a major side effect in cancer patients undergoing clinical chemotherapy treatment regimens. The role of sex dimorphism with regards to the mechanisms of CIPN and analgesia against CIPN remains unclear. Previous studies have found that the infiltration of immune cells, such as macrophages into DRGs and their subsequent activation promote CIPN. Interestingly, the contribution of microglia to CIPN appears to be limited. Here, we show that macrophage TLR9 signaling promotes CIPN in male mice only. This study suggests that pathways in macrophages may be sex-dimorphic in CIPN. Our findings provide new insights into the role of macrophage signaling mechanisms underlying sex dimorphism in CIPN, which may inspire the development of more precise and effective therapies.

Inflammatory and Neuropathic Gene Expression Signatures of Chemotherapy-Induced Neuropathy Induced by Vincristine, Cisplatin, and Oxaliplatin in C57BL/6J Mice

Vincristine, oxaliplatin, and cisplatin are commonly prescribed chemotherapeutic agents for the treatment of many tumors. However, a main side effect is chemotherapy-induced peripheral neuropathy (CIPN), which may lead to changes in chemotherapeutic treatment. Although symptoms associated with CIPN are recapitulated by mouse models, there is limited knowledge of how these drugs affect the expression of genes in sensory neurons. The present study carried out a transcriptomic analysis of dorsal root ganglia following vincristine, oxaliplatin, and cisplatin treatment with a view to gain insight into the comparative pathophysiological mechanisms of CIPN. RNA-Seq revealed 368, 295, and 256 differential expressed genes induced by treatment with vincristine, oxaliplatin, and cisplatin, respectively, and only 5 shared genes were dysregulated in all 3 groups. Cell type enrichment analysis and gene set enrichment analysis showed predominant effects on genes associated with the immune system after treatment with vincristine, while oxaliplatin treatment affected mainly neuronal genes. Treatment with cisplatin resulted in a mixed gene expression signature. PerspectiveThese results provide insight into the recruitment of immune responses to dorsal root ganglia and indicate enhanced neuroinflammatory processes following administration of vincristine, oxaliplatin, and cisplatin. These gene expression signatures may provide insight into novel drug targets for treatment of CIPN.

Tubulin-VDAC Interaction: Molecular Basis for Mitochondrial Dysfunction in Chemotherapy-Induced Peripheral Neuropathy.

Tubulin is a well-established target of microtubule-targeting agents (MTAs), a widely used class of chemotherapeutic drugs. Yet, aside from their powerful anti-cancer efficiency, MTAs induce a dose-limiting and debilitating peripheral neurotoxicity. Despite intensive efforts in the development of neuroprotective agents, there are currently no approved therapies to effectively manage chemotherapy-induced peripheral neuropathy (CIPN). Over the last decade, attempts to unravel the pathomechanisms underlying the development of CIPN led to the observation that mitochondrial dysfunctions stand as a common feature associated with axonal degeneration. Concomitantly, mitochondria emerged as crucial players in the anti-cancer efficiency of MTAs. The findings that free dimeric tubulin could be associated with mitochondrial membranes and interact directly with the voltage-dependent anion channels (VDACs) located in the mitochondrial outer membrane strongly suggested the existence of an interplay between both subcellular compartments. The biological relevance of the interaction between tubulin and VDAC came from subsequent in vitro studies, which found dimeric tubulin to be a potent modulator of VDAC and ultimately of mitochondrial membrane permeability to respiratory substrates. Therefore, one of the hypothetic mechanisms of CIPN implies that MTAs, by binding directly to the tubulin associated with VDAC, interferes with mitochondrial function in the peripheral nervous system. We review here the foundations of this hypothesis and discuss them in light of the current knowledge. A focus is set on the molecular mechanisms behind MTA interference with dimeric tubulin and VDAC interaction, the potential relevance of tubulin isotypes and availability as a free dimer in the specific context of MTA-induced CIPN. We further highlight the emerging interest for VDAC and its interacting partners as a promising therapeutic target in neurodegeneration.

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.

An updated understanding of the mechanisms involved in chemotherapy-induced neuropathy.

The burdensome condition of chemotherapy-induced peripheral neuropathy occurs with various chemotherapeutics, including bortezomib, oxaliplatin, paclitaxel and vincristine. The symptoms, which include pain, numbness, tingling and loss of motor function, can result in therapy titrations that compromise therapy efficacy. Understanding the mechanisms of chemotherapy-induced peripheral neuropathy is therefore essential, yet incompletely understood. The literature presented here will address a multitude of molecular and cellular mechanisms, beginning with the most well-understood cellular and molecular-level changes. These modifications include alterations in voltage-gated ion channels, neurochemical transmission, organelle function and intracellular pathways. System-level alterations, including changes to glial cells and cytokine activation are also explored. Finally, we present research on the current understanding of genetic contributions to this condition. Suggestions for future research are provided.

Wen-Luo-Tong Decoction Attenuates Paclitaxel-Induced Peripheral Neuropathy by Regulating Linoleic Acid and Glycerophospholipid Metabolism Pathways

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious dose-limiting toxicity of many anti-neoplastic agents, especially paclitaxel, and oxaliplatin. Up to 62% of patients receiving paclitaxel regimens turn out to develop CIPN. Unfortunately, there are so few agents proved effective for prevention or management of CIPN. The reason for the current situation is that the mechanisms of CIPN are still not explicit. Traditional Chinese Medicine (TCM) has unique advantages for dealing with complex diseases. Wen-Luo-Tong (WLT) is a TCM ointment for topical application. It has been applied for prevention and management of CIPN clinically for more than 10 years. Previous animal experiments and clinical studies had manifested the availability of WLT. However, due to the unclear mechanisms of WLT, further transformation has been restricted. To investigate the therapeutic mechanisms of WLT, a metabolomic method on the basis of UPLC- MS was developed in this study. Multivariate analysis techniques, such as principal component analysis (PCA) and partial least squares discriminate analysis (PLS-DA), were applied to observe the disturbance in the metabolic state of the paclitaxel-induced peripheral neuropathy (PIPN) rat model, as well as the recovering tendency of WLT treatment. A total of 19 significant variations associated with PIPN were identified as biomarkers. Results of pathway analysis indicated that the metabolic disturbance of pathways of linoleic acid (LA) metabolism and glycerophospholipid metabolism. WLT attenuated mechanical allodynia and rebalanced the metabolic disturbances of PIPN by primarily regulating LA and glycerophospholipid metabolism pathway. Further molecular docking analysis showed some ingredients of WLT, such as hydroxysafflor yellow A (HSYA), icariin, epimedin B and 4-dihydroxybenzoic acid (DHBA), had high affinity to plenty of proteins within these two pathways.

Chemotherapy-induced peripheral neuropathy: evidence from genome-wide association studies and replication within multiple myeloma patients

BackgroundBased on the possible shared mechanisms of chemotherapy-induced peripheral neuropathy (CIPN) for different drugs, we aimed to aggregate results of all previously published genome-wide association studies (GWAS) on CIPN, and to replicate them within a cohort of multiple myeloma (MM) patients.MethodsFollowing a systematic literature search, data for CIPN associated single nucleotide polymorphisms (SNPs) with P-values< 10− 5 were extracted; these associations were investigated within a cohort of 983 German MM patients treated with bortezomib, thalidomide or vincristine. Cases were subjects that developed CIPN grade 2–4 while controls developed no or sub-clinical CIPN. Logistic regression with additive model was used.ResultsIn total, 9 GWASs were identified from the literature on CIPN caused by different drugs (4 paclitaxel, 2 bortezomib, 1 vincristine, 1 docetaxel, and 1 oxaliplatin). Data were extracted for 526 SNPs in 109 loci. One hundred fourty-eight patients in our study population were CIPN cases (102/646 bortezomib, 17/63 thalidomide and 29/274 vincristine). In total, 13 SNPs in 9 loci were replicated in our population (p-value< 0.05). The four smallest P-values relevant to the nerve function were 0.0006 for rs8014839 (close to the FBXO33 gene), 0.004 for rs4618330 (close to the INTU gene), 0.006 for rs1903216 (close to the BCL6 gene) and 0.03 for rs4687753 (close to the IL17RB gene).ConclusionsReplicated SNPs provide clues of the molecular mechanism of CIPN and can be strong candidates for further research aiming to predict the risk of CIPN in clinical practice, particularly rs8014839, rs4618330, rs1903216, and rs4687753, which showed relevance to the function of nervous system.

Protective Effect of a Mitochondria-Targeted Peptide against the Development of Chemotherapy-Induced Peripheral Neuropathy in Mice.

Several chemotherapeutic agents used for cancer treatment induce dose-limiting peripheral neuropathy that compromises patients' quality of life and limits cancer treatment. Recently, mitochondrial dysfunction has been shown to be involved in the mechanism of chemotherapy-induced peripheral neuropathy. SS-20 is a mitochondria-targeted peptide that promotes mitochondrial respiration and restores mitochondrial bioenergetics. In the present study, we examined the protective effect of SS-20 against the development of chemotherapy-induced peripheral neuropathy utilizing a murine model of peripheral neuropathy induced by oxaliplatin, a first-line chemotherapy agent for colon cancer. Weekly administrations of oxaliplatin induced peripheral neuropathy as demonstrated by the development of neuropathic pain and loss of intraepidermal nerve fibers in the hind paw. Continuous administration of SS-20 protected against the development of oxaliplatin-induced neuropathic pain and mitigated the loss of intraepidermal nerve fibers to normal levels. Our findings suggest that SS-20 may be a drug candidate for the prevention of chemotherapy-induced peripheral neuropathy.

Paclitaxel Reduces Axonal Bclw to Initiate IP3R1-Dependent Axon Degeneration

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of many cancer treatments. The hallmark of CIPN is degeneration of long axons required for transmission of sensory information; axonal degeneration causes impaired tactile sensation and persistent pain. Currently the molecular mechanisms of CIPN are not understood, and there are no available treatments. Here we show that the chemotherapeutic agent paclitaxel triggers CIPN by altering IP3 receptor phosphorylation and intracellular calcium flux, and activating calcium-dependent calpain proteases. Concomitantly paclitaxel impairs axonal trafficking of RNA-granules and reduces synthesis of Bclw (bcl2l2), a Bcl2 family member that binds IP3R1 and restrains axon degeneration. Surprisingly, Bclw or a stapled peptide corresponding to theBclw BH4 domain interact with axonal IP3R1 and prevent paclitaxel-induced degeneration, while Bcl2 andBclxL cannot do so. Together these data identify a Bclw-IP3R1-dependent cascade that causes axon degeneration and suggest that Bclw-mimetics could provide effective therapy to prevent CIPN.

Neurophysiological and clinical outcomes in chemotherapy-induced neuropathy in cancer.

Chemotherapy induced peripheral neuropathy (CIPN) is a significant toxicity of cancer treatment, with the potential to affect long-term function and quality of life in cancer survivors. There remains a lack of consensus around optimal assessment techniques. While current approaches to CIPN assessment are focused on clinical grading scales, it is becoming increasingly evident that a more comprehensive multimodal assessment package is necessary to accurately characterise the impact of CIPN as well as gauge the utility of neuroprotective mechanisms. Neurophysiological techniques provide objective biomarkers and may enable early detection of toxicity while patient reported outcomes are necessary to determine the significance of symptoms to individual patients. In addition to providing an objective assessment, clinical neurophysiological techniques provide important insights into the contributory pathophysiological mechanisms of CIPN with different chemotherapy agents. There is a paucity of implementation of these techniques in the clinical trial setting. The present Review aims to facilitate the use of neurophysiological studies as part of comprehensive assessment packages for the monitoring of CIPN by summarising current understanding of neurophysiological changes that underlie the development of neuropathy, clinical presentations and patient reported outcomes as well as advantages and limitations of current techniques for the neurophysiological assessment of CIPN.

Patients' Induced Pluripotent Stem Cells to Model Drug Induced Adverse Events: A Role in Predicting Thiopurine Induced Pancreatitis?

Induced pluripotent stem cells (iPSC) can be produced from adult cells by transfecting them with a definite set of pluripotency-associated genes. Under adequate growth conditions and stimulation iPSC can differentiate to almost every somatic lineage in the body. Patients' derived iPSC are an innovative model to study mechanisms of adverse drug reactions in individual patients and in cell types that cannot be easily obtained from human subjects. Proof-of concept studies with known toxicants have been performed for liver, cardiovascular and central nervous system cells: neurons obtained from iPSC have been used to elucidate the mechanism of chemotherapy-induced peripheral neuropathy by evaluating the effects of neurotoxic drugs such as vincristine. However, no study has been performed yet on pancreatic tissue and drug induced pancreatitis. Thiopurines (azathioprine and mercaptopurine) are immunosuppressive antimetabolite drugs, commonly used to treat Crohn's disease. About 5% of Crohn's disease patients treated with thiopurines develop pancreatitis, a severe idiosyncratic adverse event; these patients have to stop thiopurine administration and may require medical treatment, with significant personal and social costs. Molecular mechanism of thiopurine induced pancreatitis (TIP) is currently unknown and no fully validated biomarker is available to assist clinicians in preventing this adverse event. Hence, in this review we have reflected upon the probable research applications of exocrine pancreatic cells generated from patient specific iPS cells. Such pancreatic cells can provide excellent insights into the molecular mechanism of TIP. In particular three hypotheses on the mechanism of TIP could be explored: drug biotransformation, innate immunity and adaptative immunity.

Significant response to lacosamide in a patient with severe chemotherapy-induced peripheral neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting toxicity of potentially curative cancer therapy regimens. Cisplatin is the class of chemotherapy agent that has a broad spectrum of activity against several solid tumors, but it induces sensory neuropathy of upper and lower extremities. Cisplatin-induced peripheral neuropathy is usually in a "gloves and socks" distribution that can persist for months or years after completion of chemotherapy treatment. If the pain is severe, it affects the patient's long-term quality of life and can potentially result in chemotherapy dose reduction or treatment discontinuation. The mechanism of CIPN is not well understood, and a number of pathophysiological mechanisms have been proposed to explain the phenomenon. Although many therapies have been investigated for the prevention or treatment of CIPN, there is currently no accepted proven therapy. Here we report a case in which lacosamide alleviated painful CIPN symptoms. Lacosamide is an anticonvulsant drug that blocks the voltage-gated sodium channels in the neurons and may also be a promising novel candidate for the prevention and treatment of chemotherapy-induced peripheral neuropathy. Preclinical data support the role of lacosamide protective effect in a rat model of chemotherapy-induced neuropathy, randomized clinical trial is needed.

Enhanced Excitability of Primary Sensory Neurons and Altered Gene Expression of Neuronal Ion Channels in Dorsal Root Ganglion in Paclitaxel-induced Peripheral Neuropathy

The mechanism of chemotherapy-induced peripheral neuropathy after paclitaxel treatment is not well understood. Given the poor penetration of paclitaxel into central nervous system, peripheral nervous system is most at risk. Intrinsic membrane properties of dorsal root ganglion neurons were studied by intracellular recordings. Multiple-gene real-time polymerase chain reaction array was used to investigate gene expression of dorsal root ganglion neuronal ion channels. Paclitaxel increased the incidence of spontaneous activity from 4.8 to 27.1% in large-sized and from 0 to 33.3% in medium-sized neurons. Paclitaxel decreased the rheobase (nA) from 1.6 ± 0.1 to 0.8 ± 0.1 in large-sized, from 1.5 ± 0.2 to 0.6 ± 0.1 in medium-sized, and from 1.6 ± 0.2 to 1.0 ± 0.1 in small-sized neurons. After paclitaxel treatment, other characteristics of membrane properties in each group remained the same except that Aδ neurons showed shorter action potential fall time (ms) (1.0 ± 0.2, n = 10 vs. 1.8 ± 0.3, n = 9, paclitaxel vs. vehicle). Meanwhile, real-time polymerase chain reaction array revealed an alteration in expression of some neuronal ion channel genes including up-regulation of hyperpolarization-activated cyclic nucleotide-gated channel 1 (fold change 1.76 ± 0.06) and Nav1.7 (1.26 ± 0.02) and down-regulation of Kir channels (Kir1.1, 0.73 ± 0.05, Kir3.4, 0.66 ± 0.06) in paclitaxel-treated animals. The increased neuronal excitability and the changes in gene expression of some neuronal ion channels in dorsal root ganglion may provide insight into the molecular and cellular basis of paclitaxel-induced neuropathy, which may lead to novel therapeutic strategies.

Iatrogenic neuropathies

This review discusses the literature on peripheral neuropathy caused by medication-induced toxicity or immunological mechanism with special attention to recent advancements. The number of reports of immune-mediated neuropathies associated with antitumor necrosis factor alpha (anti-TNFalpha) therapy is increasing. But long-term follow-up suggests that the cessation of anti-TNFalpha therapy is not always necessary. The cases of acute inflammatory demyelinating polyneuropathy induced by polyethylene glycol-interferon alpha-2a and of polyradiculoneuropathy induced by polyethylene glycol-interferon alpha-2b were reported for the first time, and the latter was associated with antiganglioside antibodies. The mechanism of chemotherapy-induced peripheral neuropathy is still in the process of being elucidated with the use of animal models or axonal excitability techniques. In the phase III Assessment of Proteasome Inhibitor for Extending Remissions trial, it proved that dose modification using a specific guideline improved bortezomib-induced peripheral neuropathy management. Peripheral neuropathy can be associated with anti-TNFalpha therapy or interferon alpha therapy, and to the contrary, anti-TNFalpha therapy or interferon alpha therapy may have potential as a treatment option for a spectrum of immune-mediated neuropathy, similar to a double-edged sword. To take advantage of the effect of chemotherapy and to reduce neurotoxicity, a guideline of dose modification is useful.

Chemotherapy-Induced Peripheral Neuropathy: A Review and Implications for Oncology Nursing Practice

Advances in supportive care have increased the likelihood that previously less common adverse effects of chemotherapy will be more evident. The incidence of chemotherapy-induced peripheral neuropathy (CIPN) is increasing because more neurotoxic drugs have been developed and because patients are living longer and receiving multiple chemotherapy regimens. This article reviews the anatomy of the peripheral nervous system, the proposed mechanisms of CIPN, and manifestations of CIPN from vinca alkaloids, taxanes, and platinum analogs. Major topics of this article are evidence-based data regarding symptom management, a review of medical management, and a synthesis of nursing care for patients at risk for or experiencing CIPN.