Development Of Chemotherapy-induced Peripheral Neuropathy Research Articles

The Relationship of Chemotherapy-Induced Peripheral Neuropathy and Obesity: A Systematic Review

Background:Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting neurotoxic effect of chemotherapy that affects many survivors. Obesity is also known to have a negative effect on neuropathy. This review aimed to determine what relationship, if any, obesity might have with the incidence and severity of CIPN.Methods:Electronic databases PubMed, PEDro (Physiotherapy Evidence Database), CENTRAL (Cochrane Central Register of Controlled Trials), Ovid, and EBSCO were systematically searched from January 2008 to March 2019. All types of studies, data collections, and review articles were included in the adult population.Results:Twelve articles describing relationships between overweight/obesity and presence of CIPN were included in the review. Associations between body mass index (BMI), body surface area (BSA), and sarcopenic obesity and CIPN incidence and severity were described in patients who had received taxane therapy, platinum compound therapy, or bortezomib. Eleven of the 12 studies indicated an increased incidence of CIPN with higher BMI or BSA or sarcopenic obesity, and the 2 studies that analyzed severity of symptoms found an increase in those who were overweight/obese.Limitations:The number of studies specifically analyzing the relationship between overweight/obesity is limited. Also limiting comparison between studies is the categorization of obesity and the methods used to define CIPN.Conclusions:Overall, being overweight or obese would put one at a higher risk for development of CIPN. Clinicians should encourage healthy lifestyles to help decrease or control symptoms and/or limit dose reductions of chemotherapy. Further research regarding changes in severity of CIPN with weight loss or gain is needed.

DF2726A, a new IL-8 signalling inhibitor, is able to counteract chemotherapy-induced neuropathic pain

Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting side effect of several anti-neoplastics and a main cause of sensory disturbances in cancer survivors, negatively impacting patients’ quality of life. Peripheral nerve degeneration or small fibre neuropathy is generally accepted as the underlying mechanism in the development of CIPN. Recent evidence has contributed to clarify the determinant role of cytokines and chemokines in the process leading to neuronal hyperexcitability. Exposure to oxaliplatin triggers alterations in peripheral neuropathic pathways previously linked to IL-8 pathway. We investigated a novel selective inhibitor of IL-8 receptors, DF2726A, and showed its effects in counteracting CINP pathways, extending the relevance of the activation of IL-8 pathway to the class of platinum chemotherapeutics. Based on our results, we suggest that DF2726A might be a promising candidate for clinical treatment of CIPN conditions due to its efficacy and optimized pharmacokinetic/pharmacodynamic profile.

Biological predictors of chemotherapy-induced peripheral neuropathy (CIPN): MASCC neurological complications working group overview.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and debilitating condition associated with a number of chemotherapeutic agents. Drugs commonly implicated in the development of CIPN include platinum agents, taxanes, vinca alkaloids, bortezomib, and thalidomide analogues. As a drug response can vary between individuals, it is hypothesized that an individual's specific genetic variants could impact the regulation of genes involved in drug pharmacokinetics, ion channel functioning, neurotoxicity, and DNA repair, which in turn affect CIPN development and severity. Variations of other molecular markers may also affect the incidence and severity of CIPN. Hence, the objective of this review was to summarize the known biological (molecular and genomic) predictors of CIPN and discuss the means to facilitate progress in this field.

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.

A pilot study of oncology massage to treat chemotherapy-induced peripheral neuropathy (CIPN).

e23067 Background: Short- and long-term toxicity of platinum compounds and taxanes includes development of CIPN. Although anti-neuropathic medications are available, there is increased interest by health care providers and patients (pts) regarding the role of complementary approaches for symptom control. Therefore, we explored the role of massage therapy for symptomatic relief of chronic CIPN. Methods: This pilot study evaluated the optimum treatment schedule and initial efficacy of two treatment schedules of a standardized Swedish massage technique to treat lower extremity (LE) CIPN. Inclusion criteria: LE neuropathy attributed to oxaliplatin, paclitaxel, or docetaxel, no other history of attributable causes (concurrent upper extremity neuropathy allowed); self-reported neuropathy score ≥3, 0-10 scale; ≥ 6 months since last chemotherapy treatment; age ≥ 18. Pts were randomized to one of four groups: 1) LE massage 3 times (3X) week for 4 weeks; LE massage 2X week for 6 weeks; 3) head/neck/shoulder (control) massage 3X week for 4 weeks; or 4) control massage 2X week for 6 weeks. Massage completion rate was examined and symptoms of CIPN measured with the Pain Quality Assessment Scale [PQAS (Range: 0-10); subscales of PQAS-SP (surface pain), PQAS-DP (deep pain), and PQAS-PP (paroxysmal pain)] at baseline and at 10 weeks. Results: 71 pts fulfilled inclusion criteria: 77.5% women; 57.7% (breast cancer), and 42.3% (GI cancer); mean age 60.3 y/o (range: 40-77). Average length of time since the end of chemotherapy was > 3 yrs. Mean massage completion rates (max = 12) were 8.9 (SD 4.2) for 3X week and 9.8 (4.0) for 2X week with no statistical differences. There were no statistically significant differences in PQAS scores at follow-up between site-specific massage groups (lower extremity vs controls). Pts who had massage 3X week reported statistically and clinically significantly improved PQAS scores versus those who had massage 2X week (change scores: PQAS-SP: -2.3 vs. -0.6, p = 0.001; PQAS-DP: -2.1 vs. -0.9, p = 0.008; PQAS-PP: -2.3 vs. -1.0, p = 0.025), with sustained improvement maintained in the 3X week group, but minimal change in the 2X week group. Conclusions: We observed sustained reduction in pts with long-term CIPN up to 6 weeks after treatment completion for the more intensive 3X week massage group, regardless of massage treatment site. A large-scale efficacy trial is warranted to validate the role of oncology massage therapy for CIPN. Clinical trial information: NCT02221700.

Treatment Effects on Development of Chemotherapy-Induced Peripheral Neuropathy in Patients With Cancer

Treatment Effects on Development of Chemotherapy-Induced Peripheral Neuropathy in Patients With Cancer

Comparing the Neuroprotective Efficacy of P7C3‐A20 to Novel P7C3 Derivatives in a Rodent Model of Paclitaxel‐Induced Peripheral Neuropathy

Chemotherapy‐induced peripheral neuropathy (CIPN) is a prevalent adverse effect of anti‐cancer chemotherapeutics like paclitaxel (PTX), a microtubule targeting agent known to induce severe and persistent neuropathic pain. The development of CIPN not only diminishes the quality of life of cancer patients, but also downgrades their cancer prognosis as dose reduction or cessation of their anti‐cancer regimen are the only clinical interventions currently available for CIPN. Thus, the development of a pharmacological intervention that limits the neuropathic side‐effects of anti‐cancer chemotherapy is urgently needed. Here we tested the neuroprotective effects of the aminopropyl carbazole, P7C3‐A20 (A20), and several A20 derivatives in a rat model of paclitaxel‐induced peripheral neuropathy. All experiments were done by investigators blinded to the drug treatments. Racemic A20 (2.2, 6.6, 20 mg/kg, i.p., q.d.), or vehicle, was administered daily to male Sprague‐Dawley rats over a 14‐day period beginning 2 days before PTX treatment (11.7 mg/kg/day, i.p.; every other day for 3 injections). A20 dose‐dependently attenuated PTX‐induced mechanical allodynia in rats. Evaluation of intraepidermal nerve fiber (IENF) density in rat paw biopsies using immunohistochemical staining revealed that treatment with PTX produced a profound loss in IENF density that was prevented by treatment with A20. Further, statistical analysis indicated strong correlations between IENF density, a diagnostic marker of CIPN in humans, and nociceptive threshold to mechanical stimuli. Enantiomer specific mixtures of A20 (20 mg/kg, i.p., q.d.), racemic A20 (20 mg/kg, i.p., q.d.), or vehicle were then administered utilizing the same behavioral paradigm and PTX dosing schedule as above. Consistent with our previous data, racemic A20 attenuated PTX‐induced mechanical allodynia and the S‐enantiomer was identified as the active component of the racemic mixture. We have also tested the neuroprotective efficacy of four novel A20 derivatives coded as compounds A through D. The A20 derivatives were administered daily at 20 mg/kg by i.p. injection and mechanical allodynia was assayed as described above. One compound, Drug C, provided robust protection against PTX‐induced mechanical allodynia, whereas the compounds A, B, and D demonstrated limited neuroprotective efficacy. Taken together, A20 and perhaps its derivatives are an exciting new class of pharmacological agents that may have clinical utility for alleviating peripheral neuropathies caused by various anti‐cancer chemotherapeutics.Support or Funding InformationSupported in part by Calico Life Sciences and Proneurotech.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

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.

Cisplatin educates CD8+ T cells to prevent and resolve chemotherapy-induced peripheral neuropathy in mice.

The mechanisms responsible for the persistence of chemotherapy-induced peripheral neuropathy (CIPN) in a significant proportion of cancer survivors are still unknown. Our previous findings show that CD8 T cells are necessary for the resolution of paclitaxel-induced mechanical allodynia in male mice. In this study, we demonstrate that CD8 T cells are not only essential for resolving cisplatin-induced mechanical allodynia, but also to normalize spontaneous pain, numbness, and the reduction in intraepidermal nerve fiber density in male and female mice. Resolution of CIPN was not observed in Rag2 mice that lack T and B cells. Reconstitution of Rag2 mice with CD8 T cells before cisplatin treatment normalized the resolution of CIPN. In vivo education of CD8 T cells by cisplatin was necessary to induce resolution of CIPN in Rag2 mice because adoptive transfer of CD8 T cells from naive wild-type mice to Rag2 mice after completion of chemotherapy did not promote resolution of established CIPN. The CD8 T-cell-dependent resolution of CIPN does not require epitope recognition by the T-cell receptor. Moreover, adoptive transfer of cisplatin-educated CD8 T cells to Rag2 mice prevented CIPN development induced by either cisplatin or paclitaxel, indicating that the activity of the educated CD8 T is not cisplatin specific. In conclusion, resolution of CIPN requires in vivo education of CD8 T cells by exposure to cisplatin. Future studies should examine whether ex vivo CD8 T cell education could be applied as a therapeutic strategy for treating or preventing CIPN in patients.

HMGB1 as a target for prevention of chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) considerably impairs cancer patients' QOL, and may lead to discontinuation of drug treatment of cancer. Currently, there is no effective strategy against CIPN. Therefore, it is an urgent issue to develop clinically available drugs that prevent or treat CIPN. We have shown that high mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) molecule, plays an essential role in the development of CIPN. Most interestingly, thrombomodulin α, approved as a medicine for treatment of disseminated intravascular coagulation (DIC) in Japan, causes thrombin-dependent degradation of extracellular HMGB1 that is released in response to chemotherapeutics, and prevents CIPN. Thus, we expect that targeting HMGB1 or its receptors would lead to prevention of CIPN in cancer patients in near future.

Targeting Axon Integrity to Prevent Chemotherapy-Induced Peripheral Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is an irreversible off-target adverse effect of many chemotherapeutic agents such as paclitaxel, yet its mechanism is poorly understood and no preventative measure is available. CIPN is characterized by peripheral nerve damages resulting in permanent sensory function deficits. Our recent unbiased genome-wide analysis revealed that heat shock protein (Hsp) 27 is part of a transcriptional network induced by axonal injury and highly enriched for genes involved in adaptive neuronal responses, particularly axonal regeneration. To examine if Hsp27 could prevent the occurrence of CIPN, we first demonstrated that paclitaxel-induced allodynia was associated directly with axonal degeneration in sensory neurons in a mouse model of CIPN. We therefore hypothesize that by preventing axonal degeneration could prevent the development of CIPN. We drove expression of human Hsp27 (hHsp27) specifically in neurons. Development of mechanical and thermal allodynia was prevented completely in paclitaxel-treated hHsp27 transgenic mice. Strikingly, hHsp27 protected against paclitaxel-induced neurotoxicity in vivo including degeneration of afferent nerve fibers, demyelination, mitochondrial swelling, apoptosis, and restored sensory nerve action potential. Finally, we delineated signaling cascades that link CIPN development to caspase 3 and RhoA/cofilin activation in sensory neurons and peripheral nerves. hHsp27 exerted anti-apoptotic effect and maintained axon integrity by restoring caspase 3 and RhoA expression to basal levels. Taken together, our data suggest that by preventing axonal degeneration might prove beneficial as anti-CIPN drugs, which represents an emerging research area for therapeutic development.

Trial designs for chemotherapy-induced peripheral neuropathy prevention

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially dose-limiting side effect of neurotoxic chemotherapies. No therapies are available to prevent CIPN. The small number of positive randomized clinical trials (RCTs) evaluating preventive therapies for CIPN provide little guidance to inform the design of future trials. Moreover, the lack of consensus regarding major design features in this area poses challenges to development of new therapies. An Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities and Networks (ACTTION)-Consortium on Clinical Endpoints and Procedures for Peripheral Neuropathy Trials (CONCEPPT) meeting attended by neurologists, oncologists, pharmacists, clinical trialists, statisticians, and regulatory experts was convened to discuss design considerations and provide recommendations for CIPN prevention trials. This article outlines considerations related to design of RCTs that evaluate preventive therapies for CIPN including (1) selection of eligibility criteria (e.g., cancer types, chemotherapy types, inclusion of preexisting neuropathy); (2) selection of outcome measures and endpoints, including those that incorporate alterations in chemotherapy dosing, which may affect the rate of CIPN development and its severity; (3) potential effects of the investigational therapy on the efficacy of chemotherapy; and (4) sample size estimation. Our hope is that attention to the design considerations and recommendations outlined in this article will improve the quality and assay sensitivity of CIPN prevention trials and thereby accelerate the identification of efficacious therapies.

Predictive biomarkers of chemotherapy-induced peripheral neuropathy: a review.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of taxane treatment during chemotherapy. Identifying predictive biomarkers of CIPN would allow physicians to alter treatment given to patients according to a personal risk of developing this condition. The current literature on CIPN biomarkers is reviewed, identifying biomarkers which have been found to be significantly related to CIPN. Three genetic biomarkers are identified (ARHGEF10 rs9657362, CYP2C8 rs11572080/rs10509681 and FGD4 rs10771973) which have been found to act as predictive CIPN biomarkers in multiple studies. Possible mechanisms underlying the relationship between these single nucleotide polymorphisms and CIPN development are explored. The biomarkers identified in this study should be investigated further to generate predictive biomarkers that may be used in a clinical setting.

Subclinical Peripheral Neuropathy in Patients with Head and Neck Cancer: A Quantitative Sensory Testing (QST) Study

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and chronic complication associated with cancer treatment. Prior investigations have demonstrated the presence of subclinical peripheral neuropathy in patients with colorectal cancer even before the patients had received chemotherapy. Objective: To investigate subclinical peripheral neuropathy of the upper limbs in patients with squamous cell carcinoma (SCC) of the head and neck which developed before their exposure to neurotoxic anticancer agents. Study Design: Retrospective analysis. Methods: With the use of our quantitative sensory testing (QST) data bank, we retrospectively assessed the afferent fiber function of 25 patients with SCC of the head and neck before they had received chemotherapy (the patient group) and compared our findings with those from 23 healthy control patients. Skin temperature, sensorimotor function, sharpness detection, thermal detection, and touch detection (using both von Frey monofilaments and the Bumps detection test) were measured. Results: Touch thresholds were statistically higher in the patient group than in the healthy volunteer group at the palm (mean [± SD], 0.54 g [± 0.07 g] and 0.27 g [± 0.05 g], respectively [P < 0.01]) and at the forearm (0.74 g [± 0.12 g] and 0.41 g [± 0.08 g] [P < 0.05]). There was also a clear deficit in touch sensation as indicated by a Bumps detection threshold in patients of 6.5 µm ± 0.8 µm and in controls of 3.7 µm ± 0.5 µm. This yields an elevation in threshold to 165% in the patients relative to that of the control volunteers. The grooved pegboard test showed delayed completion times for patients compared with controls, with differences of 18.65 seconds in the dominant hand and of 23.36 seconds in the nondominant hand. The sharpness detection thresholds did not differ between patients and volunteers. Limitations: Inadequacies in the original data acquisition and documentation of the QST and the medical records could not be addressed due to the retrospective nature of the study. In addition, based on available information, we did not find an objective parameter able to correlate the QST findings with pre-pain levels. Conclusion: Patients with SCC were found to have deficits in sensory function before undergoing treatment, suggesting that cancer itself alters peripheral nerve function and may contribute to the development of CIPN. These results confirm the sensitivity of the Bumps detection test and highlight its potential role in early detection of peripheral neuropathy, especially in cancer patients for whom chemotherapies associated with CIPN have been prescribed. Key words: Peripheral neuropathy, head and neck cancer, quantitative sensory testing

Abstract 602: The α7 nicotinic acetylcholine receptor silent agonist R-47 prevents and reverses paclitaxel-induced peripheral neuropathy without enhancing the proliferation of lung cancer cells or interfering with paclitaxel-induced antitumor activity

Abstract While cancer chemotherapy continues to significantly contribute to the number of cancer survivors, exposure to these drugs can often result in chemotherapy-induced peripheral neuropathy (CIPN), a consequence of peripheral nerve fiber dysfunction or degeneration. CIPN is characterized by sensory symptoms such as numbness, burning, and allodynia, resulting in an overall decrease in quality of life. Paclitaxel (Taxol), a microtubule poison that is commonly used to treat breast, lung, and ovarian cancers, has been found to cause CIPN in 59-78% of cancer patients. There is currently no effective preventative or therapeutic treatment for this side effect, which can be a dose-limiting factor for chemotherapy or delay treatment. Our laboratories have previously shown that nicotine, the prototypical nicotinic acetylcholine receptor (nAChR) agonist, can prevent and reverse paclitaxel-induced peripheral neuropathy without increasing lung tumor growth in mice. Our current studies have demonstrated that the α7 nAChR silent agonist R-47 may be a promising preventative and therapeutic treatment for CIPN as well. R-47 (10 mg/kg, p.o.) was administered to male C57BL/6J mice treated with paclitaxel (8 mg/kg, i.p., every other day for a total of four injections). Von Frey filament testing revealed that R-47 can both prevent and reverse paclitaxel-induced mechanical allodynia; the latter effect can be inhibited by the α7 nAChR antagonist methyllycaconitine. In support of these findings, R-47 also prevents the reduction of intra-epidermal nerve fibers in the hind paws of paclitaxel-treated mice. In addition, α7 nAChR knockout mice exhibit a greater and sustained increase in mechanical allodynia after paclitaxel administration when compared to wild-type mice, suggesting the involvement of this receptor subtype in hindering CIPN development and/or maintenance. With regard to cancer, R-47 fails to increase A549 and H460 non-small cell lung cancer cell viability, colony formation, or proliferation alone, and does not interfere with paclitaxel-induced growth arrest, apoptosis, or DNA fragmentation. Most importantly, R-47 does not increase the growth of A549 tumors or interfere with the antitumor activity of paclitaxel in tumor-bearing mice. These data suggest that the use of an α7 nAChR silent agonist may be a safe and efficacious approach for the prevention and treatment of CIPN. Citation Format: S Lauren Kyte, Wisam Toma, Ganeshsingh Thakur, M Imad Damaj, David A. Gewirtz. The α7 nicotinic acetylcholine receptor silent agonist R-47 prevents and reverses paclitaxel-induced peripheral neuropathy without enhancing the proliferation of lung cancer cells or interfering with paclitaxel-induced antitumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 602.

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.

(253) - Chemotherapy-induced pain is promoted by enhanced spinal adenosine kinase levels via astrocyte-dependent mechanisms

Development of chronic pain associated with chemotherapy-induced peripheral neuropathy (CIPN) compromises the effectiveness of chemotherapies to treat cancers and greatly impacts thousands of lives. The causative mechanisms remain poorly understood. However, emerging evidence implicates unchecked neuroinflammation as a determinant factor in its development. We now demonstrate that the dysregulation of adenosine metabolism and loss of its signaling govern the extent of neuroinflammation in oxaliplatin-treated rodents. Adenosine kinase (ADK), a prominent regulator of extracellular and intracellular levels of the potent neuroprotective purine, adenosine, increased in the cytoplasm of astrocytes in the spinal cord of oxaliplatin-treated rats. Inhibiting its activity with intrathecal (i.th.) ADK inhibitor, ABT702, prevented the development of pain and restored anti-inflammatory and neuroprotective A3AR signaling. Increased ADK was associated with increased expression of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome protein and pro-inflammatory/neuroexcitatory cytokine, interleukin-1β (IL-1β). Inhibiting NLRP3 activity with i.th. administration of its inhibitor, MCC950, prevented the development of pain. Moreover, supplementing A3AR signaling with the highly selective A3AR agonist, MRS5698, attenuated the oxaliplatin activation of NLRP3/IL-1β pathways and the development of pain. Our previous findings suggest that the beneficial effects of A3AR agonists in neuropathic pain are associated with increased IL-10. Indeed, i.th. MRS5698 increased IL-10 expression in oxaliplatin-treated rats, which in turn was found to suppress NLPR3 and IL-1β expression in the spinal cord and attenuate pain. These findings provide new molecular insights linking the development of CIPN with astrocyte-based adenosine/ADK axis and NLRP3 inflammasome to govern neuroinflammation. Our data also implicate IL-10 in the mechanism of action of selective A3AR agonists and strengthen the pharmacological rationale for clinical evaluation as an adjunct to chemotherapy. This study was funded by the NIH/National Cancer Institute (NIH RO1 CA169519; D.S.) and the NIDDK Intramural Research Program (Z01 DK031117-26; K.J.).

The prevention of chemotherapy induced peripheral neuropathy by concurrent treatment with drugs used for bipolar disease: a retrospective chart analysis in human cancer patients.

Peripheral neuropathy is a major adverse effect in the use of chemotherapeutic drugs. In nearly 50% of patients, chemotherapy induced peripheral neuropathy (CIPN) has been reported as irreversible. With increasing numbers of patients surviving treatment as well as increasing duration of survival after treatment, reducing the side effects of chemotherapy and improving the quality of life has become a major focus of cancer survivorship. Multiple classes of chemotherapeutic drugs including taxanes, platinum agents and vinka alkaloids list peripheral neuropathy as the main dose-limiting side effect of treatment. We previously found that drugs that interfere with the microtubule function, including taxanes and vinca alkaloids, bind to neuronal calcium sensor 1 (NCS1), leading to aberrant calcium signaling. The altered calcium signaling can be mitigated by application of drugs used to treat bipolar disease (e.g., lithium and valproic acid) prior to initiation of chemotherapy. Because pre-treatment with these drugs prevented CIPN in mice treated with taxanes, we sought clinical evidence by performing a retrospective chart review study of the VA electronic health record to see whether or not there would be evidence to support our scientific belief that patients treated with lithium or valproic acid while receiving chemotherapy have a lower risk for development of CIPN than patients who received chemotherapy alone. Our data did provide evidence supporting the belief that treatment with lithium or valproic acid concurrently with chemotherapy was associated with a decreased incidence of developing CIPN.

Depletion of nerve growth factor in chemotherapy-induced peripheral neuropathy associated with hematologic malignancies.

ObjectiveTo investigate whether the depletion of nerve growth factor (NGF) is associated with the development of chemotherapy-induced peripheral neuropathy (CIPN) in patients with hematologic malignancy.MethodsWe prospectively enrolled hematologic cancer patients who had a plan to receive bortezomib, thalidomide, or vincristine. Baseline NGF levels were measured within one week before the start date of chemotherapy. Follow-up NGF levels were measured after four months from the start date of chemotherapy or the date when CIPN was initially diagnosed.ResultsBaseline and follow-up NGF pairs were measured in 45 patients (male/female = 27/18, median age = 63 years old). CIPN has developed in 28 patients. In the CIPN group, the level of NGF was significantly decreased after chemotherapy compared to the baseline (△NGF = −3.52 ±5.72; p-value = 0.003), while the NGF level of the no-CIPN group was not changed after chemotherapy. The differences in △NGF levels between the CIPN and no-CIPN group were more profound when analyzed in the subgroup of newly diagnosed multiple myeloma patients (△NGF = −4.14 ± 4.87 pg/ml for the CIPN group and +2.52 ± 8.39 pg/ml for the no-CIPN group; p-value = 0.043).ConclusionsThis study shows that the depletion of NGF occurs during the development of CIPN, suggesting pathogenesis based on the role of NGF and therapeutic implications.

Single and combined effects of Δ9 -tetrahydrocannabinol and cannabidiol in a mouse model of chemotherapy-induced neuropathic pain.

The non-psychoactive phytocannabinoid cannabidiol (CBD) can affect the pharmacological effects of Δ9 -tetrahydrocannabinol (THC). We tested the possible synergy between CBD and THC in decreasing mechanical sensitivity in a mouse model of paclitaxel-induced neuropathic pain. We also tested the effects of CBD on oxaliplatin- and vincristine-induced mechanical sensitivity. Paclitaxel-treated mice (8.0mg·kg-1 i.p., days 1, 3, 5 and 7) were pretreated with CBD (0.625-20.0mg·kg-1 i.p.), THC (0.625-20.0mg·kg-1 i.p.) or CBD+THC (0.04+0.04-20.0+20.0mg·kg-1 i.p.), and mechanical sensitivity was assessed on days 9, 14 and 21. Oxaliplatin-treated (6.0mg·kg-1 i.p., day 1) or vincristine-treated mice (0.1mg·kg-1 i.p. days 1-7) were pretreated with CBD (1.25-10.0mg·kg-1 i.p.), THC (10.0mg·kg-1 i.p.) or THC+CBD (0.16mg·kg-1 THC+0.16mg·kg-1 CBD i.p.). Both CBD and THC alone attenuated mechanical allodynia in mice treated with paclitaxel. Very low ineffective doses of CBD and THC were synergistic when given in combination. CBD also attenuated oxaliplatin- but not vincristine-induced mechanical sensitivity, while THC significantly attenuated vincristine- but not oxaliplatin-induced mechanical sensitivity. The low dose combination significantly attenuated oxaliplatin- but not vincristine-induced mechanical sensitivity. CBD may be potent and effective at preventing the development of chemotherapy-induced peripheral neuropathy, and its clinical use may be enhanced by co-administration of low doses of THC. These treatment strategies would increase the therapeutic window of cannabis-based pharmacotherapies.