Chemotherapy-induced peripheral neuropathy: prevention and treatment strategies

HDAC6 inhibition effectively reverses chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy is one of the most common dose-limiting side effects of cancer treatment. Currently, there is no Food and Drug Administration-approved treatment available. Histone deacetylase 6 (HDAC6) is a microtubule-associated deacetylase whose function includes regulation of α-tubulin-dependent intracellular mitochondrial transport. Here, we examined the effect of HDAC6 inhibition on established cisplatin-induced peripheral neuropathy. We used a novel HDAC6 inhibitor ACY-1083, which shows 260-fold selectivity towards HDAC6 vs other HDACs. Our results show that HDAC6 inhibition prevented cisplatin-induced mechanical allodynia, and also completely reversed already existing cisplatin-induced mechanical allodynia, spontaneous pain, and numbness. These findings were confirmed using the established HDAC6 inhibitor ACY-1215 (Ricolinostat), which is currently in clinical trials for cancer treatment. Mechanistically, treatment with the HDAC6 inhibitor increased α-tubulin acetylation in the peripheral nerve. In addition, HDAC6 inhibition restored the cisplatin-induced reduction in mitochondrial bioenergetics and mitochondrial content in the tibial nerve, indicating increased mitochondrial transport. At a later time point, dorsal root ganglion mitochondrial bioenergetics also improved. HDAC6 inhibition restored the loss of intraepidermal nerve fiber density in cisplatin-treated mice. Our results demonstrate that pharmacological inhibition of HDAC6 completely reverses all the hallmarks of established cisplatin-induced peripheral neuropathy by normalization of mitochondrial function in dorsal root ganglia and nerve, and restoration of intraepidermal innervation. These results are especially promising because one of the HDAC6 inhibitors tested here is currently in clinical trials as an add-on cancer therapy, highlighting the potential for a fast clinical translation of our findings.

Beyond symptomatic relief for chemotherapy-induced peripheral neuropathy: Targeting the source

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious adverse side effect of many chemotherapeutic agents, affecting >60% of patients with cancer. Moreover, CIPN persists long into survivorship in approximately 20% to 30% of these patients. To the authors' knowledge, no drugs have been approved to date by the US Food and Drug Administration to effectively manage chemotherapy-induced neuropathic pain. The majority of the drugs tested for the management of CIPN aim at symptom relief, including pain and paresthesia, yet are not very efficacious. The authors propose that there is a need to acquire a more thorough understanding of the etiology of CIPN so that effective, mechanism-based, disease-modifying interventions can be developed. It is important to note that such interventions should not interfere with the antitumor effects of chemotherapy. Mitochondria are rod-shaped cellular organelles that represent the powerhouses of the cell, in that they convert oxygen and nutrients into the cellular energy "currency" adenosine triphosphate. In addition, mitochondria regulate cell death. Neuronal mitochondrial dysfunction and the associated nitro-oxidative stress represent crucial final common pathways of CIPN. Herein, the authors discuss the potential to prevent or reverse CIPN by protecting mitochondria and/or inhibiting nitro-oxidative stress with novel potential drugs, including the mitochondrial protectant pifithrin-μ, histone deacetylase 6 inhibitors, metformin, antioxidants, peroxynitrite decomposition catalysts, and anti-inflammatory mediators including interleukin 10. This review hopefully will contribute toward bridging the gap between preclinical research and the development of realistic novel therapeutic strategies to prevent or reverse the devastating neurotoxic effects of chemotherapy on the (peripheral) nervous system. Cancer 2018;124:2289-98. © 2018 American Cancer Society.

Changes in upper extremity function, ADL, and HRQoL in colorectal cancer patients after the first chemotherapy cycle with oxaliplatin: a prospective single-center observational study

PURPOSE

Oxaliplatin, an important chemotherapeutic agent in colorectal cancer, causes chemotherapy-induced peripheral neuropathy (CIPN), for which prophylactic or therapeutic interventions are lacking. We aimed to investigate changes in upper extremities, activities of daily living (ADL), and health-related quality of life (HRQoL) parameters after the first chemotherapy cycle.

METHODS

Thirty-eight colorectal cancer patients scheduled to receive the leucovorin, 5'-fluorouracil, oxaliplatin (FOLFOX) therapy or the capecitabine, oxaliplatin (CAPOX) therapy, participated. Patients underwent objective assessment of sensory function, muscular strength, and manual dexterity and answered the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and the Disabilities of the Arm, Shoulder, and Hand-Disability/Symptom (DASH-DS) questionnaires for subjective assessment. The CIPN was assessed at baseline and prior to the second drug cycle.

RESULTS

Light touch sensation in both hands worsened significantly after the first drug cycle, though no significant changes were observed in muscular strength and manual dexterity. The QLQ-C30 analysis showed that Physical Functioning, Role Functioning, Nausea and Vomiting, and Dyspnea were significantly worse, whereas Emotional Functioning was improved. The DASH-DS analysis revealed significant worsening of dysfunction and subjective symptoms.

CONCLUSIONS

Our results suggest that light touch sensation may worsen even in the absence of multiple chemotherapy cycles. Even if arm and hand function (muscular strength and manual dexterity) is apparently intact, patients may experience dysfunction and decreased HRQoL. For preserving or improving patients' ADL and HRQoL, it is imperative to provide support at chemotherapy initiation.

Chemotherapy-Associated Peripheral Neuropathy in Patients With Early-Stage Breast Cancer: A Systematic Review

Breast cancer is the most common cancer among women worldwide, and survival rates are increasing. Chemotherapy-associated peripheral neuropathy (PN) is clinically important because of effects on quality of life (QOL) and potential effects on dose limitations. This adverse drug reaction is associated with certain classes of chemotherapy and commonly presents as peripheral sensory neuropathy whose natural course is largely unknown. The literature was reviewed to determine the frequency and characteristics of PN associated with adjuvant chemotherapy in early-stage breast cancer (ESBC) to explore the potential impact on long-term (one or more years after diagnosis) health outcomes and QOL. MEDLINE, PubMed, Embase, and the Cochrane Library were searched for relevant English-language randomized controlled trials, systematic reviews, meta-analyses, and case-control and cohort studies published between January 1990 and July 1996. Included studies were limited to current adjuvant regimens (eg, anthracyclines, taxanes, cyclophosphamide, platinum compounds). Two investigators independently reviewed abstracts, full-text articles, and extracted data from fair- and good-quality studies. Discrepancies in quality assessment and data extraction were resolved by consensus. We identified 364 articles; 60 were eligible for full-text review. Only five reports of four studies provided data beyond one year post-treatment initiation. Studies used different measures to assess PN. Neuropathic symptoms persisted in 11.0% to more than 80% of participants at one to three years following treatment. There is a paucity of data describing persistent PN in ESBC patients. Consistent use of validated measures and well-conducted randomized clinical trials or observational studies are needed to evaluate the incidence, persistence, and QOL associated with the long-term effects of PN.

Human mesenchymal stem cells lose their functional properties after paclitaxel treatment

Mesenchymal stem cells (MSCs) are an integral part of the bone marrow niche and aid in the protection, regeneration and proliferation of hematopoietic stem cells after exposure to myelotoxic taxane anti-cancer agents, but the influence of taxane compounds on MSCs themselves remains incompletely understood. Here, we show that bone marrow-derived MSCs are highly sensitive even to low concentrations of the prototypical taxane compound paclitaxel. While MSCs remained metabolically viable, they were strongly impaired regarding both their proliferation and their functional capabilities after exposure to paclitaxel. Paclitaxel treatment resulted in reduced cell migration, delays in cellular adhesion and significant dose-dependent inhibition of the stem cells’ characteristic multi-lineage differentiation potential. Cellular morphology and expression of the defining surface markers remained largely unaltered. Paclitaxel only marginally increased apoptosis in MSCs, but strongly induced premature senescence in these stem cells, thereby explaining the preservation of the metabolic activity of functionally inactivated MSCs. The reported sensitivity of MSC function to paclitaxel treatment may help to explain the severe bone marrow toxicities commonly caused by taxane-based anti-cancer treatments.

Paclitaxel alleviated liver injury of septic mice by alleviating inflammatory response via microRNA-27a/TAB3/NF-κB signaling pathway

Excessive inflammatory response and apoptosis play an important role in the sepsis-induced liver injury. Paclitaxel, a diterpene alkaloid of Taxus brevifolia, is widely used as an anti-tumor drug and shows protective effects on acute lung and kidney injury. However, whether it has a protective effect against sepsis-induced liver injury has not been reported. The objective of this study was to investigate the protective effects of paclitaxel in septic liver injury in mice and associated molecular mechanisms. Our results showed that paclitaxel treatment improved LPS-induced liver injury, as evidenced by the reduced aminotransferase activity, histological scores and apoptosis in the liver tissues. This was accompanied by the alleviating of inflammation and oxidative stress, such as decreased levels of tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-6) interleukin-1β (IL-1β) and malondialdehyde (MDA) and increased levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in serum and liver tissues. Subsequent microarray and qRT-PCR analysis further showed that miR-27a was significantly decreased in mice with sepsis, which was recovered by paclitaxel pretreatment. Antagomir-miR-27a suppressed the therapeutic effects of paclitaxel in mice liver injury model via promoting inflammatory response. Of note, TAB3, which participated in the activation of the NF-κB signaling pathway, was identified as a direct target of miR-27 by luciferase reporter gene assays. Then, we revealed a reverse relationship between miR-27a expression levels and TAB3 mRNA levels in liver tissues from septic mice. Furthermore, paclitaxel treatment significantly decreased the expression of NF-κB p65, but increased inhibitor of nuclear factor-κB-α (IκBα) protein levels in septic mice, suggesting the inactivation of NF-κB signaling pathway. Notably, the inhibitory effects of paclitaxel on NF-κB signaling pathway were reversed by antagomir-miR-27a. Our data indicated that paclitaxel significantly attenuated septic induced liver injury through reducing inflammatory response via miR-27a/TAB3/NF-κB signaling pathway.

Treatment of vincristine-induced ileus with metoclopramide: A case report

INTRODUCTION

Acute lymphoblastic leukemia is an invasive malignancy which ought to be treated with several cytotoxic medications. Vincristine-based regimen is among the most commonly used regimens for the treatment of adult acute lymphoblastic leukemia. Peripheral neuropathy caused by vincristine provides a limitation in dose administration and can influence the treatment outcome and patient's quality of life.

CASE PRESENTATION

Ileus and constipation occurred as a result of autonomic neuropathy in a 58-year-old man who underwent vincristine-based regimen for acute lymphoblastic leukemia treatment. Despite the administration of several laxative agents for constipation, the complication did not improve. So metoclopramide as a prokinetic agent was administered intravenously, and patient bowel movement and defecation started after 24 h.

CONCLUSIONS

There is no approved protocol for vincristine-induced autonomic neuropathy treatment; thus, prokinetic agents such as metoclopramide can be considered as an option for ileus treatment after ruling out the possibility of bowel obstruction. Prophylactic stool softeners should be administrated in all patients undergoing chemotherapy with vincristine to prevent gastrointestinal motility disorders.

Adipose-derived stem cells decrease pain in a rat model of oxaliplatin-induced neuropathy: Role of VEGF-A modulation

Oxaliplatin therapy of colorectal cancer induces a dose-dependent neuropathic syndrome in 50% of patients. Pharmacological treatments may offer limited relief; scientific efforts are needed for new therapeutic approaches. Therefore we evaluated in a preclinical setting the pain relieving properties of mesenchymal stem cells and its secretome. Rat adipose stem cells (rASCs) were administered in a rat model of oxaliplatin-induced neuropathy. A single intravenous injection of rASCs reduced oxaliplatin-dependent mechanical hypersensitivity to noxious and non-noxious stimuli taking effect 1 h after administration, peaking 6 h thereafter and lasting 5 days. Cell-conditioned medium was ineffective. Repeated rASCs injections every 5 days relieved pain each time with a comparable effect. Labeled rASCs were detected in the bloodstream 1 and 3 h after administration and found in the liver 24 h thereafter. In oxaliplatin-treated rats, the plasma concentration of vascular endothelial growth factor (pan VEGF-A) was increased while the isoform VEGF₁₆₅b was upregulated in the spinal cord. Both alterations were reverted by rASCs. The anti-VEGF-A monoclonal antibody bevacizumab (intraperitoneally) reduced oxaliplatin-dependent pain. Studying the peripheral and central role of VEGF₁₆₅b in pain, we determined that the intraplantar and intrathecal injection of the growth factor induced a pro-algesic effect. In the oxaliplatin neuropathy model, the intrathecal infusion of bevacizumab, anti-rat VEGF₁₆₅b antibody and rASCs reduced pain. Adult adipose mesenchymal stem cells could represent a novel approach in the treatment of neuropathic pain. The regulation of VEGF-A is suggested as an effective mechanism in the complex response orchestrated by stem cells against neuropathy.

Duloxetine Protects against Oxaliplatin-Induced Neuropathic Pain and Spinal Neuron Hyperexcitability in Rodents

Oxaliplatin is a widely used chemotherapy agent, but induces serious peripheral neuropathy. Duloxetine is a dual reuptake inhibitor of serotonin and norepinephrine, and is shown to be effective against pain. However, whether and how duloxetine can attenuate oxaliplatin-induced allodynia in rodents is not clearly understood. A single injection of oxaliplatin (6 mg/kg, intraperitoneal; i.p.) induced a cold and mechanical allodynia, which was assessed by acetone and von Frey filament tests, respectively. When significant allodynic signs were observed, three different doses of duloxetine (10, 30, and 60 mg/kg, i.p.) were injected. Administration of 30 and 60 mg/kg of duloxetine significantly reduced the allodynia, whereas 10 mg/kg did not. By using an in vivo extracellular recording method, we further confirmed that 30 mg/kg of duloxetine could significantly inhibit the hyperexcitability of spinal wide dynamic range (WDR) cells. The anti-allodynic effect of duloxetine was completely blocked by an intrathecal injection of phentolamine (non-selective α-adrenergic receptor antagonist, 20 μg), or prazosin (α₁-adrenergic receptor antagonists, 10 μg); however, idazoxan (α₂-adrenergic receptor antagonist, 10 μg) did not block it. In conclusion, we suggest that duloxetine may have an effective protective action against oxaliplatin-induced neuropathic pain and spinal hyperexcitability, which is mediated by spinal α₁-adrenergic receptors.

Secondary Hodgkin Lymphoma and Myelodysplastic Syndrome (MDS) After Paclitaxel-Carboplatin Treatment in a Patient with Small Cell Lung Cancer

Herein synchronous occurrence of Hodgkin lymphoma and secondary myelodysplastic syndrome in a 60 year old male patient with small cell lung cancer treated with combined chemotherapy (carboplatin and paclitaxel) and radiotherapy is presented. The objective of this report is to stress the importance of documenting and monitoring adverse drug reactions that arise from chemotherapy. After four years of treatment with the combined chemotherapy, the patient presented inguinal lymphadenopathy and enlarged lymph nodes and histopathology rapport was suggestive for plasmacytoid variant of Castleman disease. Three years later, biopsy of lymph node was performed and diagnosis of Hodgkin lymphoma - mixed cellularity has been established. Molecular analyses revealed presence of dominant monoclonal population of the immunoglobulin genes in the oligo/monoclonal background. Bone marrow biopsy findings suggested secondary myelodysplasia and revealed signs of hematopoietic cells dismaturation with signs of megaloblastic maturation of the erytropoetic lineage, appearance of ALIP (abnormal localization of immature precursors) in the myeloid lineage and dysplastic megakaryocytes. In addition, an increased level of polyclonal plasmacytes (lambda vs kappa was 60%:40%) was found. Hodgkin lymphoma and MDS occurring after 4 years of carboplatin/paclitaxel therapy might be contributed to the accumulation of alkylator-related DNA damage. This emphasize the need of outlining a monitoring plan regarding development of secondary leukemia and other malignant hematological proliferations should be outlined in the protocols.

The ubiquitin-proteasome pathway in adult and pediatric brain tumors: biological insights and therapeutic opportunities

Nearly 20 years ago, the concept of targeting the proteasome for cancer therapy began gaining momentum. This concept was driven by increased understanding of the biology/structure and function of the 26S proteasome, insight into the role of the proteasome in transformed cells, and the synthesis of pharmacological inhibitors with clinically favorable features. Subsequent in vitro, in vivo, and clinical testing culminated in the FDA approval of three proteasome inhibitors-bortezomib, carfilzomib, and ixazomib -for specific hematological malignancies. However, despite in vitro and in vivo studies pointing towards efficacy in solid tumors, clinical responses broadly have been evasive. For brain tumors, a malignancy in dire need of new approaches both in adult and pediatric patients, this has also been the case. Elucidation of proteasome-dependent processes in specific types of brain tumors, the evolution of newer proteasome targeting strategies, and the use of proteasome inhibitors in combination strategies will clarify how these agents can be leveraged more effectively to treat central nervous system malignancies. Since brain tumors represent a heterogeneous subset of solid tumors, and in particular, pediatric brain tumors possess distinct biology from adult brain tumors, tailoring of proteasome inhibitor-based strategies to specific subtypes of these tumors will be critical for advancing care for affected patients, and will be discussed in this review.

Tuning the metabolism of the anticancer drug cisplatin with chemoprotective agents to improve its safety and efficacy

Numerous in vivo studies have shown that the severe toxic side-effects of intravenously administered cisplatin can be significantly reduced by the co-administration of sulfur-containing 'chemoprotective agents'. Using a metallomics approach, a likely biochemical basis for these potentially useful observations was only recently uncovered and appears to involve the reaction of chemoprotective agents with cisplatin-derived Pt-species in human plasma to form novel platinum-sulfur complexes (PSC's). We here reveal aspects of the structure of two PSC's and establish the identification of an optimal chemoprotective agent to ameliorate the toxic side-effects of cisplatin, while leaving its antineoplastic activity largely intact, as a feasible research strategy to transform cisplatin into a safer and more effective anticancer drug.

Cellular mechanisms of cyclophosphamide-induced taste loss in mice

Many commonly prescribed chemotherapy drugs such as cyclophosphamide (CYP) have adverse side effects including disruptions in taste which can result in loss of appetite, malnutrition, poorer recovery and reduced quality of life. Previous studies in mice found evidence that CYP has a two-phase disturbance in taste behavior: a disturbance immediately following drug administration and a second which emerges several days later. In this study, we examined the processes by which CYP disturbs the taste system by examining the effects of the drug on taste buds and cells responsible for taste cell renewal using immunohistochemical assays. Data reported here suggest CYP has direct cytotoxic effects on lingual epithelium immediately following administration, causing an early loss of taste sensory cells. Types II and III cells in fungiform taste buds appear to be more susceptible to this effect than circumvallate cells. In addition, CYP disrupts the population of rapidly dividing cells in the basal layer of taste epithelium responsible for taste cell renewal, manifesting a disturbance days later. The loss of these cells temporarily retards the system’s capacity to replace Type II and Type III taste sensory cells that survived the cytotoxic effects of CYP and died at the end of their natural lifespan. The timing of an immediate, direct loss of taste cells and a delayed, indirect loss without replacement of taste sensory cells are broadly congruent with previously published behavioral data reporting two periods of elevated detection thresholds for umami and sucrose stimuli. These findings suggest that chemotherapeutic disturbances in the peripheral mechanisms of the taste system may cause dietary challenges at a time when the cancer patient has significant need for well balanced, high energy nutritional intake.

Risk-reduction and treatment of chemotherapy-induced peripheral neuropathy

INTRODUCTION

Chemotherapy-induced peripheral neuropathy (CIPN), a common adverse effect of several chemotherapeutic agents, has a significant impact on quality of life and may even compromise treatment efficacy, requiring chemotherapy dose reduction or discontinuation. CIPN is predominantly related with sensory rather than motor symptoms and the most common related cytotoxic agents are platinum compounds, taxanes and vinca alkaloids. CIPN symptoms may resolve after treatment cessation, but they can also be permanent and continue for years. Areas covered: We present an overview of CIPN pathophysiology, clinical assessment, prevention and treatment identified through a Pubmed search. Expert commentary: No substantial progress has been made in the last few years within the field of prevention and/or treatment of CIPN, in spite of remarkable efforts. Continuous research could expand our knowledge about chemotherapeutic-specific neuropathic pathways and eventually lead to the conception of innovative and targeted agents for the prevention and/or treatment of this debilitating chemotherapy adverse effect.

Utilization of iPSC-derived human neurons for high-throughput drug-induced peripheral neuropathy screening

As the number of cancer survivors continues to grow, awareness of long-term toxicities and impact on quality of life after chemotherapy treatment in cancer survivors has intensified. Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common side effects of modern chemotherapy. Animal models are used to study peripheral neuropathy and predict human risk; however, such models are labor-intensive and limited translatability between species has become a major challenge. Moreover, the mechanisms underlying CIPN have not been precisely determined and few human neuronal models to study CIPN exist. Here, we have developed a high-throughput drug-induced neurotoxicity screening model using human iPSC-derived peripheral-like neurons to study the effect of chemotherapy agents on neuronal health and morphology using high content imaging measurements (neurite length and neuronal cell viability). We utilized this model to test various classes of chemotherapeutic agents with known clinical liability to cause peripheral neuropathy such as platinum agents, taxanes, vinca alkaloids, proteasome inhibitors, and anti-angiogenic compounds. The model was sensitive to compounds that cause interference in microtubule dynamics, especially the taxane, epothilone, and vinca alkaloids. Conversely, the model was not sensitive to platinum and anti-angiogenic chemotherapeutics; compounds that are not reported to act directly on neuronal processes. In summary, we believe this model has utility for high-throughput screening and prediction of human risk for CIPN for novel chemotherapeutics.

The chemotherapeutic agent paclitaxel selectively impairs reversal learning while sparing prior learning, new learning and episodic memory

Chemotherapy is widely used to treat patients with systemic cancer. The efficacy of cancer therapies is frequently undermined by adverse side effects that have a negative impact on the quality of life of cancer survivors. Cancer patients who receive chemotherapy often experience chemotherapy-induced cognitive impairment across a variety of domains including memory, learning, and attention. In the current study, the impact of paclitaxel, a taxane derived chemotherapeutic agent, on episodic memory, prior learning, new learning, and reversal learning were evaluated in rats. Neurogenesis was quantified post-treatment in the dentate gyrus of the same rats using immunostaining for 5-Bromo-2'-deoxyuridine (BrdU) and Ki67. Paclitaxel treatment selectively impaired reversal learning while sparing episodic memory, prior learning, and new learning. Furthermore, paclitaxel-treated rats showed decreases in markers of hippocampal cell proliferation, as measured by markers of cell proliferation assessed using immunostaining for Ki67 and BrdU. This work highlights the importance of using multiple measures of learning and memory to identify the pattern of impaired and spared aspects of chemotherapy-induced cognitive impairment.

Oral Application of Magnesium-L-Threonate Attenuates Vincristine-induced Allodynia and Hyperalgesia by Normalization of Tumor Necrosis Factor-α/Nuclear Factor-κB Signaling

BACKGROUND

Antineoplastic agents, including vincristine, often induce neuropathic pain and magnesium deficiency clinically, but the causal link between them has not been determined. No drug is available for treating this form of neuropathic pain.

METHODS

Injection of vincristine (0.1 mg · kg · day, intraperitoneally, for 10 days) was used to induce nociceptive sensitization, which was accessed with von Frey hairs and the plantar tester in adult male Sprague-Dawley rats. Magnesium-L- threonate was administered through drinking water (604 mg · kg · day). Extracellular and intracellular free Mg were measured by Calmagite chromometry and flow cytometry. Molecular biologic and electrophysiologic experiments were performed to expose the underlying mechanisms.

RESULTS

Vincristine injection induced allodynia and hyperalgesia (n = 12), activated tumor necrosis factor-α/nuclear factor-κB signaling, and reduced free Mg in cerebrospinal fluid by 21.7 ± 6.3% (mean ± SD; n = 13) and in dorsal root ganglion neurons by 27 ± 6% (n = 11). Reducing Mg activated tumor necrosis factor-α/nuclear factor-κB signaling in cultured dorsal root ganglion neurons. Oral application of magnesium-L-threonate prevented magnesium deficiency and attenuated both activation of tumor necrosis factor-α/nuclear factor-κB signaling and nociceptive sensitization (n = 12). Mechanistically, vincristine induced long-term potentiation at C-fiber synapses, up-regulated N-methyl-D-aspartate receptor type 2B subunit of N-methyl-D-aspartate receptor, and led to peptidergic C-fiber sprouting in spinal dorsal horn (n = 6 each). The vincristine-induced pathologic plasticity was blocked by intrathecal injection of nuclear factor-κB inhibitor (n = 6), mimicked by tumor necrosis factor-α, and substantially prevented by oral magnesium-L-threonate (n = 5).

CONCLUSIONS

Vincristine may activate tumor necrosis factor-α/nuclear factor-κB pathway by reduction of intracellular magnesium, leading to spinal pathologic plasticity and nociceptive sensitization. Oral magnesium-L-threonate that prevents the magnesium deficiency is a novel approach to prevent neuropathic pain induced by chemotherapy.

Prophylactic Administration of Aucubin Inhibits Paclitaxel-Induced Mechanical Allodynia via the Inhibition of Endoplasmic Reticulum Stress in Peripheral Schwann Cells

Paclitaxel is a chemotherapeutic agent that causes peripheral neuropathy as its major dose-limiting side effect. However, the peripheral neuropathy is difficult to manage. A study we recently conducted showed that repetitive administration of aucubin as a prophylactic inhibits paclitaxel-induced mechanical allodynia. However, the mechanisms underlying the anti-allodynic activity of aucubin, which is a major component of Plantaginis Semen, was unclear. In addition to mechanical allodynia, aucubin inhibited spontaneous and mechanical stimuli-induced firing in spinal dorsal horn neurons; however, catalpol, a metabolite of aucubin, did not show these effects. Furthermore, paclitaxel induced the expression of CCAAT/enhancer-binding protein homologous protein, a marker of endoplasmic reticulum (ER) stress, in the sciatic nerve and a Schwann cell line (LY-PPB6 cells); however, this effect was inhibited by aucubin. These results suggest that aucubin inhibits paclitaxel-induced mechanical allodynia through the inhibition of ER stress in peripheral Schwann cells.

Antiallodynic effect of β-caryophyllene on paclitaxel-induced peripheral neuropathy in mice

Painful peripheral neuropathy is a common side effect of paclitaxel (PTX). The use of analgesics is an important component for management of PTX-induced peripheral neuropathy (PINP). However, currently employed analgesics have several side effects and are poorly effective. β-caryophyllene (BCP), a dietary selective CB₂ agonist, has shown analgesic effect in neuropathic pain models, but its role in chemotherapy-induced neuropathic pain has not yet been investigated. Herein, we used the mouse model of PINP to show the therapeutic effects of BCP in this neuropathy. Male Swiss mice receiving PTX (2 mg kg^-1, ip, four alternate days) were treated with BCP (25 mg kg^-1, po, twice a day) either during or after PTX administration. Some groups were also pretreated with AM630 (CB₂ antagonist, 3 mg kg^-1, ip) or AM251 (CB₁ antagonist, 1 mg kg^-1, ip). Spinal cord samples were collected in different time points to perform immunohistochemical analysis. BCP attenuated the established mechanical allodynia induced by PTX (p < 0.0001) in a CB₂-dependent manner. Of note, when given concomitantly with PTX, BCP was able to attenuate the development of PINP (p < 0.0001). Spinal cord immunohistochemistry revealed that preventive treatment with BCP reduced p38 MAPK and NF-κB activation, as well as the increased Iba-1 and IL-1β immunoreactivity promoted by PTX. Our findings show that BCP effectively attenuated PINP, possibly through CB₂-activation in the CNS and posterior inhibition of p38 MAPK/NF-κB activation and cytokine release. Taken together, our results suggest that BCP could be used to attenuate the establishment and/or treat PINP.

Symptom clustering and quality of life in patients with ovarian cancer undergoing chemotherapy

PURPOSE

The symptom clusters in patients with ovarian cancer undergoing chemotherapy have not been well evaluated. We investigated the symptom clusters and effects of symptom clusters on the quality of life of patients with ovarian cancer.

METHOD

We recruited 210 ovarian cancer patients being treated with chemotherapy and used a descriptive cross-sectional study design to collect information on their symptoms. To determine inter-relationships among symptoms, a principal component analysis with varimax rotation was performed based on the patient's symptoms (fatigue, pain, sleep disturbance, chemotherapy-induced peripheral neuropathy, anxiety, depression, and sexual dysfunction).

RESULTS

All patients had experienced at least two domains of concurrent symptoms, and there were two types of symptom clusters. The first symptom cluster consisted of anxiety, depression, fatigue, and sleep disturbance symptoms, while the second symptom cluster consisted of pain and chemotherapy-induced peripheral neuropathy symptoms. Our subgroup cluster analysis showed that ovarian cancer patients with higher-scoring symptoms had significantly poorer quality of life in both symptom cluster 1 and 2 subgroups, with subgroup-specific patterns. The symptom clusters were different depending on age, age at disease onset, disease duration, recurrence, and performance status of patients with ovarian cancer. In addition, ovarian cancer patients experienced different symptom clusters according to cancer stage.

CONCLUSIONS

The current study demonstrated that there is a specific pattern of symptom clusters, and symptom clusters negatively influence the quality of life in patients with ovarian cancer. Identifying symptom clusters of ovarian cancer patients may have clinical implications in improving symptom management.

Herbal Medicine AC591 Prevents Oxaliplatin-Induced Peripheral Neuropathy in Animal Model and Cancer Patients

Oxaliplatin is clinically compelling because of severe peripheral neuropathy. The side effect can result in dosage reductions or even cessation of chemotherapy, and no effective treatments are available. AC591 is a standardized extract of Huangqi Guizhi Wuwu decoction, an herbal formula recorded in “Synopsis of the Golden Chamber” for improving limb numbness and pain. In this study, we investigated whether AC591 could protect against oxaliplatin-induced peripheral neuropathy. To clarify it, a rat model of oxaliplatin-induced peripheral neuropathy was established, and neuroprotective effect of AC591 was studied. Our results showed that pretreatment with AC591 reduced oxaliplatin-induced cold hyperalgesia, mechanical allodynia as well as morphological damage of dorsal root ganglion. Microarray analysis indicated the neuroprotective action of AC591 depended on the modulation of multiple molecular targets and pathways involved in the downregulation of inflammation and immune response. Moreover, AC591 enhanced the antitumor activity of oxaliplatin to some extent in Balb/c mice bearing CT-26 carcinoma cells. The efficacy of AC591 is also investigated in 72 colorectal cancer patients. After four cycles of treatment, the percentage of grades 1–2 neurotoxicity in AC591-treated group (n = 36) was 25%, whereas in the control group the incidence was 55.55% (P < 0.01) (n = 36). No significant differences in the tumor response rate between the two groups were found. These evidences suggested that AC591 can prevent oxaliplatin-induced neuropathy without reducing its antitumor activity, and may be a promising adjuvant to alleviate sensory symptoms in clinical practice.

Optimal clinical assessment strategies for chemotherapy-induced peripheral neuropathy (CIPN): a systematic review and Delphi survey

BACKGROUND/PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a prominent side effect of the treatment of cancer. Despite this frequent complication, there has been no comprehensive review and quality appraisal of CIPN assessments. The purpose of this study is to provide a definitive quality appraisal of CIPN assessment strategies for clinical use.

METHODS

Relevant studies were identified through database searches of Medline, Embase, CINAHL, and Cochrane. CIPN assessment strategies from included articles were extracted and initially rated by an oncologist and neurophysiologist according to criteria related to assessment depth, comprehensiveness, appropriateness, and reliability. The six highest scoring assessment strategies were the focus of a two-round Delphi survey of a working party of 32 physicians, nurses, and consumers to achieve consensus on the highest rated assessments for each criterion.

RESULTS

The database search yielded 117 distinct CIPN assessments that were extracted from 2373 articles. Three patient-reported outcome surveys and three clinician-based assessments were included in the Delphi survey. No consensus was generated regarding the best overall CIPN assessment, although good (≥70%) consensus was achieved regarding the best assessment within each criterion. The Participant Neurotoxicity Questionnaire (PNQ) was rated the highest overall and patient-reported outcome (PRO) assessment, while the Total Neuropathy Score clinical version (TNSc) was the highest rated clinician-based assessment.

CONCLUSIONS

A diverse range of CIPN assessments currently exists. While several assessments assess CIPN symptoms with adequate comprehensiveness, depth, language, and feasibility, the consensus 'gold standard' clinical assessment remains to be established.

Noradrenergic inhibition of spinal hyperexcitation elicited by cutaneous cold stimuli in rats with oxaliplatin-induced allodynia: electrophysiological and behavioral assessments

We investigated the spinal action of noradrenaline on cold-elicited hyperexcitation detected in dorsal horn neurons of rats with allodynia induced by an oxaliplatin (6 mg/kg, i.p.) injection. In vivo extracellular recordings from the spinal dorsal horn showed that wide dynamic range neurons responded to cutaneous acetone (10 μl) stimulation in normal rats, and cold-elicited firings in oxaliplatin-administered rats were increased with a longer duration, correlated with behavioral responses. These responses were significantly attenuated by spinal administration (50 μM) of noradrenaline or its agonists, clonidine (α2), phenylephrine (α1) and isoprenaline (β), in descending order of efficacy. Thus, the inhibitory effect of noradrenaline on spinal oxaliplatin-induced cold hyperexcitation is mediated mainly by activation of α2- and/or α1-adrenoceptors.

Melatonin prevents mitochondrial dysfunction and promotes neuroprotection by inducing autophagy during oxaliplatin-evoked peripheral neuropathy

Oxaliplatin, an organoplatinum compound, is used in the treatment of colorectal cancer, but its clinical use can be limited due to the development of peripheral neuropathy. Whilst mitochondrial dysfunction has been implicated as a major pathomechanism for oxaliplatin-induced neurotoxicity, the prevention of autophagy may also aggravate neuronal cell death. Melatonin, a well-known mitoprotectant and autophagy inducer, was used to examine its neuroprotective role in oxaliplatin-induced peripheral neuropathy (OIPN). Melatonin prevented the loss of mitochondrial membrane potential (Ψm) and promoted neuritogenesis in oxaliplatin-challenged neuro-2a cells. It did not interfere with the cytotoxic activity of oxaliplatin in human colon cancer cell line, HT-29. Melatonin treatment significantly alleviated oxaliplatin-induced pain behavior and neuropathic deficits in rats. It also ameliorated nitro-oxidative stress mediated by oxaliplatin, thus prevented nitrosylation of proteins and loss of antioxidant enzymes, and therefore, it improved mitochondrial electron transport chain function and maintained cellular bioenergetics by improving the ATP levels. The protective effects of melatonin were attributed to preventing oxaliplatin-induced neuronal apoptosis by increasing the autophagy pathway (via LC3A/3B) in peripheral nerves and dorsal root ganglion (DRG). Hence, it preserved the epidermal nerve fiber density in oxaliplatin-induced neuropathic rats. Taken together, we provide detailed molecular mechanisms for the neuroprotective effect of melatonin and suggest it has translational potential for oxaliplatin-induced neuropathy.

Herbal medicines and chemotherapy induced peripheral neuropathy (CIPN): A critical literature review

BACKGROUND

Chemotherapy induced peripheral neuropathy [CIPN] is a common significant and debilitating side-effect resulting from the administration of neurotoxic chemotherapeutic agents. These pharmaco-chemotherapeutics can include taxanes, vinca alkaloids, platinum analogues, and others. Moderate to severe CIPN significantly decreases the quality of life and physical abilities of cancer patients and current pharmacotherapy for CIPN e.g. Amifostine, and antidepressants have had limited efficacy and may themselves induce adverse side-effects.

METHODS

To determine the potential use of herbal medicines as adjuvants in cancer treatments, a critical literature review was conducted by electronic and manual search on nine databases. These include PubMed, the Cochrane Library, Science Direct, Scopus, EMBASE, MEDLINE, Google Scholar, and two Chinese databases CNKI and CINAHL. Thirty-four studies were selected from 5614 studies assessed and comprising animal studies, case reports, retrospective studies, and minimal randomized clinical trials investigating the anti-CIPN effect of herbal medicines as the adjuvant intervention in patients administered chemotherapy. The thirty-four studies were assessed on methodological quality and limitations identified.

RESULTS

Studies were mixed in their recommendations for herbal medicines as an adjuvant treatment for CIPN.

CONCLUSION

Currently no agent has shown solid beneficial evidence to be recommended for the treatment or prophylaxis of CIPN. Given that the number of cancer survivors is increasing, the long-term side effects of cancer treatment, is of major importance.

Structure-based design and SAR development of 5,6-dihydroimidazolo[1,5-f]pteridine derivatives as novel Polo-like kinase-1 inhibitors

Using structure-based drug design, we identified a novel series of 5,6-dihydroimidazolo[1,5-f]pteridine PLK1 inhibitors. Rational improvements to compounds of this class resulted in single-digit nanomolar enzyme and cellular activity against PLK1, and oral bioavailability. Compound 1 exhibits >7 fold induction of phosphorylated Histone H3 and is efficacious in an in vivo HT-29 tumor xenograft model.

Prophylactic topical paeoniflorin prevents mechanical allodynia caused by paclitaxel in mice through adenosine A1 receptors

BACKGROUND

The chemotherapeutic agent paclitaxel (PTX) causes refractory peripheral neuropathy as a side effect. Prophylactic oral administration of the traditional herbal medicine Shakuyakukanzoto containing Paeoniae Radix and Glycyrrhizae Radix prevents the development of PTX-induced mechanical allodynia in mice via peripheral effects, mostly due to Paeoniae Radix. However, the bioactive component responsible for the prevention of PTX-induced neuropathic pain remains unknown.

PURPOSE

To determine whether a monoterpene glycoside paeoniflorin (PF), which is the principal bioactive constituent of Paeoniae Radix, has inhibitory effects on PTX-induced mechanical allodynia and investigate the underlying mechanisms.

METHODS

C57BL/6NCr mice received a single intraperitoneal injection of PTX and then were topically administered PF to the planar surface twice daily for 13 days. Mechanical allodynia was evaluated by the von Frey filament test, peripheral nerve activity was recorded using bipolar electrodes, and demyelination in peripheral nerves was analysed by electron microscopy. Schwann cell line LY-PPB6 pre-treated with PF and then treated with PTX was used to analyse the expression of the transcription factor CHOP, a marker of endoplasmic reticulum (ER) stress, by western blotting.

RESULTS

PTX caused mechanical allodynia and increased both spontaneous and mechanical stimuli-evoked peripheral nerve activities, whereas repetitive topical application of PF significantly attenuated PTX-induced allodynia, suppressed saphenous nerve firing, and inhibited demyelination in the plantar nerve. Moreover, in cultured Schwann cells, PF downregulated PTX-induced expression of CHOP, indicating the inhibition of ER stress. The attenuation of mechanical allodynia in mice and downregulation of CHOP levels in cell cultures was inhibited by adenosine A₁ receptor (A1R) antagonist 8-cyclopentyl-1,3-diprooylxanrhine, suggesting the involvement of A1R in PF-associated analgesic effects.

CONCLUSION

These results suggest that prophylactic topical application of PF is effective in alleviating PTX-induced mechanical allodynia by protecting sensory nerves from demyelination via activation of the A1R.

Rikkunshito prevents paclitaxel-induced peripheral neuropathy through the suppression of the nuclear factor kappa B (NFκB) phosphorylation in spinal cord of mice

Peripheral neuropathy is the major side effect caused by paclitaxel, a microtubule-binding antineoplastic drug. Paclitaxel-induced peripheral neuropathy causes a long-term negative impact on the patient's quality of life. However, the mechanism underlying paclitaxel-induced peripheral neuropathy is still unknown, and there is no established treatment. Ghrelin is known to attenuate thermal hyperalgesia and mechanical allodynia in chronic constriction injury of the sciatic nerve, and inhibit the activation of nuclear factor kappa B (NFκB) in the spinal dorsal horn. Rikkunshito (RKT), a kampo medicine, increases the secretion of ghrelin in rodents and humans. Thus, RKT may attenuate paclitaxel-induced peripheral neuropathy by inhibiting phosphorylated NFκB (pNFκB) in the spinal cord. We found that paclitaxel dose-dependently induced mechanical hyperalgesia in mice. Paclitaxel increased the protein levels of spinal pNFκB, but not those of spinal NFκB. NFκB inhibitor attenuated paclitaxel-induced mechanical hyperalgesia suggesting that the activation of NFκB mediates paclitaxel-induced hyperalgesia. RKT dose-dependently attenuated paclitaxel-induced mechanical hyperalgesia. Ghrelin receptor antagonist reversed the RKT-induced attenuation of paclitaxel-induced mechanical hyperalgesia. RKT inhibited the paclitaxel-induced increase in the protein levels of spinal pNFκB. Taken together, the present study indicates that RKT exerts an antihyperalgesic effect in paclitaxel-induced neuropathic pain by suppressing the activation of spinal NFκB.

Navigating Treatment of Metastatic Castration- Resistant Prostate Cancer: Nursing Perspectives

BACKGROUND

Treatment of metastatic castration-resistant prostate cancer (mCRPC) has evolved rapidly. In particular, five new treatments that extend survival in mCRPC have been approved since 2010, including the chemotherapy cabazitaxel (Jevtana®), hormonal agents abiraterone (Zytiga®) and enzalutamide (Xtandi®), vaccine sipuleucel-T (Provenge®), and radiopharmaceutical radium-223 (Xofigo®); all have different indications and toxicity profiles.

OBJECTIVES

This review discusses treatment advances in mCRPC, including considerations for side-effect management and treatment sequencing. Studies relating to quality of care in prostate cancer are also discussed.

METHODS

Nonsystematic searches were performed on published manuscripts and abstracts from major oncology or urology congresses, focusing on practical characteristics of the previously mentioned new treatments that extend survival in mCRPC, as well as studies relating to quality of care and the role of nurses in prostate cancer management.

FINDINGS

To ensure that patients derive optimal clinical benefit, assessing overall health and proactively managing expected side effects are essential. Treatment sequencing in mCRPC is an important consideration, but clinical data in this area are limited. Despite medical advances in mCRPC, studies have identified other aspects of care in which improvement is needed. Nurses can make major contributions to addressing supportive care needs, which has been shown to improve patient care and outcomes in prostate cancer. Although patient navigation programs have improved coordination of care, inconsistent implementation among centers has been identified for prostate cancer. Greater use of outcome measures can help to identify unmet patient needs.

Characterisation of Immune and Neuroinflammatory Changes Associated with Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) and associated neuropathic pain is a debilitating adverse effect of cancer treatment. Current understanding of the mechanisms underpinning CIPN is limited and there are no effective treatment strategies. In this study, we treated male C57BL/6J mice with 4 cycles of either Paclitaxel (PTX) or Oxaliplatin (OXA) over a week and tested pain hypersensitivity and changes in peripheral immune responses and neuroinflammation on days 7 and 13 post 1^st injection. We found that both PTX and OXA caused significant mechanical allodynia. In the periphery, PTX and OXA significantly increased circulating CD4+ and CD8+ T-cell populations. OXA caused a significant increase in the percentage of interleukin-4+ lymphocytes in the spleen and significant down-regulation of regulatory T (T-reg) cells in the inguinal lymph nodes. However, conditional depletion of T-reg cells in OXA-treated transgenic DEREG mice had no additional effect on pain sensitivity. Furthermore, there was no leukocyte infiltration into the nervous system of OXA- or PTX-treated mice. In the peripheral nervous system, PTX induced expression of the neuronal injury marker activating transcription factor-3 in IB4+ and NF200+ sensory neurons as well as an increase in the chemokines CCL2 and CCL3 in the lumbar dorsal root ganglion. In the central nervous system, PTX induced significant astrocyte activation in the spinal cord dorsal horn, and both PTX and OXA caused reduction of P2ry12+ homeostatic microglia, with no measurable changes in IBA-1+ microglia/macrophages in the dorsal and ventral horns. We also found that PTX induced up-regulation of several inflammatory cytokines and chemokines (TNF-α, IFN-γ, CCL11, CCL4, CCL3, IL-12p70 and GM-CSF) in the spinal cord. Overall, these findings suggest that PTX and OXA cause distinct pathological changes in the periphery and nervous system, which may contribute to chemotherapy-induced neuropathic pain.

Tempol Ameliorates and Prevents Mechanical Hyperalgesia in a Rat Model of Chemotherapy-Induced Neuropathic Pain

Chemotherapy-induced neuropathic pain is difficult to treat and prevent. Tempol decreases cellular superoxide radical levels and oxidative stress. The aims of our study were to investigate the analgesic and preventive effects of tempol on paclitaxel-induced neuropathic pain in rats and to identify the associated mechanisms of action. Neuropathic pain was induced with intraperitoneally injected paclitaxel on four alternate days in male Sprague-Dawley rats. Tempol was administered systemically as a single injection and a continuous infusion before or after the injection of paclitaxel. The mechanical threshold for allodynia, protein levels, and free radical levels were measured using von Frey filaments, Western blotting, and live cell imaging, respectively. After the rats developed neuropathic pain behavior, a single intraperitoneal injection and continuous infusion of tempol ameliorated paclitaxel-induced mechanical allodynia. Systemic infusion of tempol in the early phase of the development of pain behavior prevented the development of paclitaxel-induced pain behavior. Paclitaxel increased the levels of phosphorylated protein kinase C, phosphorylated nuclear factor κB, phosphodiesterase 4D (PDE4D), IL-1β, and monocyte chemoattractant protein-1 in the lumbar dorsal root ganglia; however, tempol decreased these levels. Paclitaxel also increased superoxide levels in a culture of primary dorsal root ganglion cells and tempol decreased these levels. In conclusion, tempol alleviates and prevents chemotherapy-induced neuropathic pain in rats by reducing the levels of inflammatory cytokines and free radicals in dorsal root ganglia.

Paclitaxel-induced increase in mitochondrial volume mediates dysregulation of intracellular Ca2+ in putative nociceptive glabrous skin neurons from the rat

We have recently demonstrated that in a rat model of chemotherapy-induced peripheral neuropathy (CIPN), there is a significant decrease in the duration of the depolarization-evoked Ca²⁺ transient in small diameter, IB4+, and capsaicin-responsive neurons innervating the glabrous skin of the hindpaw. This change was specific to the transient duration and significantly smaller if not undetectable in neurons innervating the dorsal skin of the hindpaw or the skin of the inner thigh. Given the importance of mitochondria in intracellular Ca²⁺ regulation and the findings of chemotherapy-associated increase in mitotoxicity along the sensory neuron axons, we hypothesized that CIPN is due to both increases and decreases in mitochondria function, with changes manifest in distinct subpopulations of afferents. To begin to test this hypothesis, we used confocal microscopy and Ca²⁺ imaging in combination with pharmacological manipulations to study paclitaxel-induced changes in retrograde tracer-labeled neurons from naïve, vehicle-treated, and paclitaxel-treated rats. Paclitaxel treatment was not associated with decreased mitochondrial membrane potential or increased superoxide levels in the somata of putative nociceptive glabrous skin neurons. However, it was associated with significant increases in the relative contribution of mitochondria to the control of the evoked Ca²⁺ transient duration in putative nociceptive glabrous skin neurons, as well as increases in mitotracker and Tom20 staining which reflected an increase in mitochondrial volume. Furthermore, the relative contribution of the sarco-endoplasmic reticulum Ca²⁺ ATPase to the regulation of the duration of the depolarization evoked Ca²⁺ transient was also increased in this subpopulation of neurons from paclitaxel treated rats. Our results indicate that the paclitaxel-induced decrease in the duration of the evoked Ca²⁺ transient is due to both direct and indirect influences of mitochondria. It remains to be determined if and how these changes contribute to the manifestation of CIPN.

Anti-allodynic effect of Buja in a rat model of oxaliplatin-induced peripheral neuropathy via spinal astrocytes and pro-inflammatory cytokines suppression

BACKGROUND

Oxaliplatin, a widely used anticancer drug against metastatic colorectal cancer, can induce acute peripheral neuropathy, which is characterized by cold and mechanical allodynia. Activation of glial cells (e.g. astrocytes and microglia) and increase of pro-inflammatory cytokines (e.g. IL-1β and TNF-α) in the spinal cord play a crucial role in the pathogenesis of neuropathic pain. Our previous study demonstrated that Gyejigachulbu-Tang (GBT), a herbal complex formula, alleviates oxaliplatin-induced neuropathic pain in rats by suppressing spinal glial activation. However, it remains to be elucidated whether and how Buja (Aconiti Tuber), a major ingredient of GBT, is involved in the efficacy of GBT.

METHODS

Cold and mechanical allodynia induced by an oxaliplatin injection (6 mg/kg, i.p.) in Sprauge-Dawley rats were evaluated by a tail immersion test in cold water (4 °C) and a von Frey hair test, respectively. Buja (300 mg/kg) was orally administrated for five consecutive days after the oxaliplatin injection. Glial activation in the spinal cord was quantified by immunohistochemical staining using GFAP (for astrocytes) and Iba-1 (for microglia) antibodies. The amount of spinal pro-inflammatory cytokines, IL-1β and TNF-α, were measured by ELISA.

RESULTS

Significant behavioral signs of cold and mechanical allodynia were observed 3 days after an oxaliplatin injection. Oral administration of Buja significantly alleviated oxaliplatin-induced cold and mechanical allodynia by increasing the tail withdrawal latency to cold stimuli and mechanical threshold. Immunohistochemical analysis showed the activation of astrocytes and microglia and the increase of the IL-1β and TNF-α levels in the spinal cord after an oxaliplatin injection. Administration of Buja suppressed the activation of spinal astrocytes without affecting microglial activation and down-regulated both IL-1β and TNF-α levels in the spinal cord.

CONCLUSIONS

Our results indicate that Buja has a potent anti-allodynic effect in a rat model of oxaliplatin-induced neuropathic pain, which is associated with the inhibition of activation of astrocytes and release of pro-inflammatory cytokines in the spinal cord. Thus, our findings suggest that administration of Buja could be an alternative therapeutic option for the management of peripheral neuropathy, a common side-effect of oxaliplatin.

Proteasome inhibitors in glioblastoma

Glioblastomas (GBM) are the tumors originating from the star shaped supportive cells in brain known as astrocytes. These tumors are highly cancerous as they have the ability to proliferate very quickly. New therapeutic strategies are being developed worldwide to fight against deadly GBM, which has median survival time of just 14 months. Proteasome inhibition is an upcoming strategy for GBM. Proteasome inhibition has shown promising results in cancers such as myeloma. However, in the recent past this form of therapy has also shown positive results in brain tumors in the form of elevated apoptosis. We searched the electronic database PubMed for pre-clinical as well as clinical controlled trials reporting importance of proteasome inhibitors during GBM. It was observed clearly that this approach is evolving and has been observed to be promising therapeutic avenue against GBM. Thus, the present review aims to enlighten the present views on use of proteasome inhibition strategy in the case of GBM.

Efficacy and safety of duloxetine in Chinese breast cancer patients with paclitaxel-induced peripheral neuropathy

Objective

Chemotherapy with paclitaxel is associated with significant neurotoxicity that may offset patients' quality of life and therapeutic benefits. This prospective, non-randomized control study evaluated the efficacy and safety of an antidepressant drug, duloxetine, at 30 or 60 mg/d, in the treatment of paclitaxel-induced peripheral neuropathy (PIPN) in Chinese breast cancer patients.

Methods

A total of 102 patients with a median age of 50 (range, 25-60) years, treated in the Department of Medical Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, between November 2014 and January 2017 were finally enrolled. Stratified by baseline characteristics, the patients were classified into two groups, receiving either duloxetine or alternative anti-neurotoxicity drugs. During the course of the paclitaxel regimen, the eligibility criteria included sensory neuropathy, as evaluated by the National Cancer Institute-Common Toxicity Criteria for Adverse Events. The treatment consisted of receiving 30 mg duloxetine (for the first 4 weeks) and 60 mg duloxetine for an additional 8 weeks, or any other anti-neurotoxicity drug daily during the same crossover period. The improvement associated with PIPN from the patient's perspective were assessed by the Functional Assessment of Cancer Therapy-Taxane (FACT-Tax) Scales, which contained questions scored from 0 to 4 (0, not at all; 4, very much; total score range, 0-44).

Results

Duloxetine was more effective in decreasing PIPN (odds ratio=5.426; 95% confidence interval, 1.898-15.514; P=0.002). Between duloxetine group and control group, the median (25th-75th percentiles) decreasing difference in the FACT-Tax pain score was 4 (2-6) vs. 1 (0-4) (P=0.005).

Conclusions

Duloxetine is a promising and safe option with tolerable toxicity at a dose of 60 mg/d for Chinese breast cancer patients with PIPN. Non-neuropathy adverse events were mild and similar in both groups. The major toxicities of duloxetine included nausea, constipation, somnolence, dizziness and distention of the eyes. Further examination of the benefits of duloxetine in the prevention of PIPN is required.

Oxaliplatin-induced Peripheral Neuropathy in South Indian Cancer Patients: A Prospective Study in Digestive Tract Cancer Patients

Purpose:

The aim of the current study is to report our prospective experience on the prevalence of oxaliplatin-induced peripheral neuropathy (OXAIPN) in patients with digestive tract cancers treated with oxaliplatin-based combination therapy.

Materials and Methods:

A total of 219 patients scheduled to be treated with oxaliplatin-based combination therapy were prospectively examined at baseline and follow-up during the therapy between November 2014 and December 2016. The incidence of acute OXAIPN was measured using a descriptive questionnaire (yes/no question) based on sum of number of symptoms present and NCI-CTCAE version 4.03 was applied to clinically grade the severity of chronic OXAIPN.

Results:

Acute and chronic OXAIPN was found in 108 of 219 (49.3%) and 127 of 219 (58%) patients, respectively. Out of 11 acute OXAIPN symptoms, the vast majority of patients manifested cold-induced pharyngolaryngeal (63.8%) dysesthesias or perioral (61.1%) paresthesias. Development of acute OXAIPN was predictive of subsequent development of chronic OXAIPN (P = 0.0001). All the patients received a median cumulative dose of 780 mg/m² (range: 130–1040 mg/m²). There was a significant correlation between the patients who received the median cumulative dose and the development of chronic OXAIPN. The incidences of OXAIPN in patients with median cumulative dose of ≤780 mg/m² was 51/120 (42.5%) and >780 mg/m² was OXAIPN 76/99 (76.7%) (P = 0.0001).

Conclusion:

The current study results demonstrate that the vast majority of patients who receive oxaliplatin-based combination chemotherapy will manifest acute OXAIPN that may contribute to the development of chronic peripheral neuropathy on repeated courses of drug administration.

Gene expression profile of sodium channel subunits in the anterior cingulate cortex during experimental paclitaxel-induced neuropathic pain in mice

Paclitaxel, a chemotherapeutic agent, causes neuropathic pain whose supraspinal pathophysiology is not fully understood. Dysregulation of sodium channel expression, studied mainly in the periphery and spinal cord level, contributes to the pathogenesis of neuropathic pain. We examined gene expression of sodium channel (Na_v) subunits by real time polymerase chain reaction (PCR) in the anterior cingulate cortex (ACC) at day 7 post first administration of paclitaxel, when mice had developed paclitaxel-induced thermal hyperalgesia. The ACC was chosen because increased activity in the ACC has been observed during neuropathic pain. In the ACC of vehicle-treated animals the threshold cycle (Ct) values for Na_v1.4, Na_v1.5, Na_v1.7, Na_v1.8 and Na_v1.9 were above 30 and/or not detectable in some samples. Thus, comparison in mRNA expression between untreated control, vehicle-treated and paclitaxel treated animals was done for Na_v1.1, Na_v1.2, Na_v1.3, Na_v1.6, Na_x as well as Na_vβ1–Na_vβ4. There were no differences in the transcript levels of Na_v1.1–Na_v1.3, Na_v1.6, Na_x, Na_vβ1–Na_vβ3 between untreated and vehicle-treated mice, however, vehicle treatment increased Na_vβ4 expression. Paclitaxel treatment significantly increased the mRNA expression of Na_v1.1, Na_v1.2, Na_v1.6 and Na_x, but not Na_v1.3, sodium channel alpha subunits compared to vehicle-treated animals. Treatment with paclitaxel significantly increased the expression of Na_vβ1 and Na_vβ3, but not Na_vβ2 and Na_vβ4, sodium channel beta subunits compared to vehicle-treated animals. These findings suggest that during paclitaxel-induced neuropathic pain (PINP) there is differential upregulation of sodium channels in the ACC, which might contribute to the increased neuronal activity observed in the area during neuropathic pain.

BMI, Lifestyle Factors and Taxane-Induced Neuropathy in Breast Cancer Patients: The Pathways Study

Background

Lifestyle factors may be associated with chemotherapy-induced peripheral neuropathy (CIPN). We examined associations between body mass index (BMI) and lifestyle factors with CIPN in the Pathways Study, a prospective cohort of women with invasive breast cancer.

Methods

Analyses included 1237 women who received taxane treatment and provided data on neurotoxicity symptoms. Baseline interviews assessed BMI (normal: <25 kg/m²; overweight: 25-29.9 kg/m²; obese: ≥30 kg/m²), moderate-to-vigorous physical activity (MVPA) (low: <2.5; medium: 2.5-5; high: >5 hours/week) and fruit/vegetable intake (low: <35 servings/week; high: ≥35 servings/week). Baseline and six-month interviews assessed antioxidant supplement use (nonuser, discontinued, continued user, initiator). CIPN was assessed at baseline, six months, and 24 months using the Functional Assessment of Cancer Therapy-Taxane Neurotoxicity (FACT-NTX); a 10% decrease was considered clinically meaningful.

Results

At baseline, 65.6% of patients in the sample were overweight or obese, 29.9% had low MVPA, 57.5% had low fruit/vegetable intake, and 9.5% reported antioxidant supplement use during treatment. In multivariable analyses, increased CIPN was more likely to occur in overweight (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.19 to 4.88) and obese patients (OR = 3.21, 95% CI = 1.52 to 7.02) compared with normal weight patients at 24 months and less likely to occur in patients with high MVPA compared with those with low MVPA at six (OR = 0.56, 95% CI = 0.34 to 0.94) and 24 months (OR = 0.43, 95% CI = 0.21 to 0.87). Compared with nonusers, patients who initiated antioxidant use during treatment were more likely to report increased CIPN at six months (OR = 3.81, 95% CI = 1.82 to 8.04).

Conclusions

Obesity and low MVPA were associated with CIPN in breast cancer patients who received taxane treatment.

Aqueous extract of Lithospermi radix attenuates oxaliplatin-induced neurotoxicity in both in vitro and in vivo models

BACKGROUND

Oxaliplatin can induce peripheral neuropathy (OXIPN) as an adverse side effect in cancer patients. Until now, no effective preventive or therapeutic drug has been developed; therefore, the dose-limiting factor of OXIPN is still an obstacle in the use of oxaliplatin to treat cancer patients. In the present study, we report for the first time that the aqueous extract of Lithospermi radix (WLR) can attenuate the OXIPN in both in vitro and in vivo neuropathic models.

METHODS

The protective effect of WLR on OXIPN was evaluated in vitro by quantifying nerve growth factor (NGF)-stimulated neurite outgrowth in PC12 cells treated with a combination of oxaliplatin and WLR. The neuroprotective potential of WLR was further confirmed by measuring the changes in nociceptive sensitivities to external mechanical stimuli in neuropathic animals induced by oxaliplatin. Histological and immunohistochemical studies were further done to examine the effect of WLR in mouse spinal cords and footpads.

RESULTS

Oxaliplatin-induced neurotoxicity in NGF-stimulated PC12 cells. It could reduce the lengths and branching numbers of neuritis in NGF-stimulated PC12 cells. Co-treatment of WLR rescued the differentiated PC12 cells from the neurotoxicity of oxaliplatin. In a chronic OXIPN animal model, administration of oxaliplatin i.p. induced enhanced nociceptive sensitivity to mechanical stimuli (25.0 to 72.5 % of response rate) along with spinal activation of microglias and astrocytes and loss of intraepidermal nerve fibers in footpads, which is remarkably suppressed by oral administration of WLR (67.5 to 35 % of response rate at the end of experiment). Cytotoxicity of oxaliplatin determined in human cancer cells was not affected irrespective of the presence of WLR.

CONCLUSIONS

In conclusion, we demonstrated that WLR can attenuate OXIPN in both in vitro and in vivo experimental models, which may be in part attributed to its anti-inflammatory activity in the spinal cord and its neuroprotective potential in the peripheral nerve system without affecting the anti-tumor potential of oxaliplatin. Therefore, WLR could be considered as a good starting material to develop a novel therapeutic agent targeting OXIPN. However, further studies should be done to elucidate the underlying mechanism such as molecular targets and active constituent(s) in WLR with neuroprotective potential.

Anti-nociceptive roles of the glia-specific metabolic inhibitor fluorocitrate in paclitaxel-evoked neuropathic pain

Paclitaxel (Taxol) is a powerful chemotherapy drug used in breast cancers, but it often causes neuropathic pain, leading to the early cessation of therapy and poor treatment outcomes. Approaches for the management of paclitaxel-induced neuropathic pain are urgently needed. The involvement of spinal astrocytes in the pathogenesis of paclitaxel-induced neuropathy has been reported, but little is known about the role of fluorocitrate (FC), a selective inhibitor of astrocyte activation, during neuropathic pain related to paclitaxel treatment. In this study, we investigated the effects of FC on paclitaxel-induced neuropathic pain. Glial fibrillary acidic protein (GFAP) expression was determined to assess astrocyte activation. To explore the mechanisms involved, the expression of glial glutamate transporter 1 (GLT-1) and the activation of mitogen-activated protein kinases in the spinal dorsal horn were analyzed. The results showed that paclitaxel decreased the mechanical nociceptive thresholds and increased GFAP expression, leading to spinal astrocyte activation. After paclitaxel treatment, GLT-1 was significantly down-regulated, and the phosphorylation of ERK1/2 and JNK were obviously up-regulated. However, paclitaxel treatment did not increase p38 phosphorylation. Additional studies showed that paclitaxel-evoked mechanical hypersensitivity was reduced by FC treatment. Moreover, FC treatment inhibited the activation of astrocytes and reversed the changes in GLT-1 expression and MAPK phosphorylation. Further study indicated that FC did not influence the antitumor effect of paclitaxel, suggesting that FC blocked paclitaxel-induced neuropathic pain without antagonizing its antitumor effect. Together, these results suggested that paclitaxel induced astrocyte-specific activation, which may contribute to mechanical allodynia and hyperalgesia, and that FC could be a potential therapeutic agent for paclitaxel-induced neuropathic pain.

Magnetic field therapy in patients with cytostatics-induced polyneuropathy: A prospective randomized placebo-controlled phase-III study

No causal treatment for chemotherapy‐induced peripheral neuropathy (CIPN) is known. Therefore, there is an urgent need to develop a therapy for CIPN. Only scarce clinical data are available concerning magnetic field therapy (MFT) in this context. We conducted a unicentric, randomized, double‐blind, placebo‐controlled phase‐III trial of an MFT device versus placebo. In this study, we randomized 44 patients with CIPN to two treatment groups, where 21 patients were treated with MFT (Group 1) and 23 patients received placebo (Group 2). We evaluated the efficacy of MFT at baseline (T₁), after 3 weeks of study treatment (T₂), and after 3 months of study treatment (T₃). The primary endpoint was nerve conduction velocity (NCV), while secondary endpoints were the Common Toxicity Criteria (CTCAE) score and the Pain Detect End Score at T₃. Seventeen of the patients in Group 1 and 14 patients in Group 2 completed the respective study treatment. The primary endpoint, significant improvement of NCV at T₃, was achieved by MFT (P = 0.015), particularly for sensory neurotoxicity of the peroneal nerve. Also, in respect to the secondary endpoints, significant improvement (P = 0.04) was achieved in terms of the patients’ subjectively perceived neurotoxicity (CTCAE score), but not of neuropathic pain (P = 0.11). From data in the randomized study presented here, a positive effect on the reduction of neurotoxicity can be assumed for the MFT device. Patients with sensory neurotoxicity in the lower limbs, especially, should therefore be offered this therapy. Bioelectromagnetics. 38:85–94, 2017. © 2016 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.

The Suppressive Effects of Cinnamomi Cortex and Its Phytocompound Coumarin on Oxaliplatin-Induced Neuropathic Cold Allodynia in Rats

Oxaliplatin, a chemotherapy drug, induces acute peripheral neuropathy characterized by cold allodynia, spinal glial activation and increased levels of pro-inflammatory cytokines. Herein, we determined whether Cinnamomi Cortex (C. Cortex), a widely used medicinal herb in East Asia for cold-related diseases, could attenuate oxaliplatin-induced cold allodynia in rats and the mechanisms involved. A single oxaliplatin injection (6 mg/kg, i.p.) induced significant cold allodynia signs based on tail immersion tests using cold water (4 °C). Daily oral administration of water extract of C. Cortex (WECC) (100, 200, and 400 mg/kg) for five consecutive days following an oxaliplatin injection dose-dependently alleviated cold allodynia with only a slight difference in efficacies between the middle dose at 200 mg/kg and the highest dose at 400 mg/kg. WECC at 200 mg/kg significantly suppressed the activation of astrocytes and microglia and decreased the expression levels of IL-1β and TNF in the spinal cord after injection with oxaliplatin. Furthermore, oral administration of coumarin (10 mg/kg), a major phytocompound of C. Cortex, markedly reduced cold allodynia. These results indicate that C. Cortex has a potent anti-allodynic effect in oxaliplatin-injected rats through inhibiting spinal glial cells and pro-inflammatory cytokines. We also suggest that coumarin might play a role in the anti-allodynic effect of C. Cortex.