Mechanisms underlying select chemotherapeutic-agent-induced neuroinflammation and subsequent neurodegeneration

Systematic screening of protein-coding gene expression identified VWF as a potential key regulator in anthracycline-based chemotherapy-exacerbated metastasis of breast cancer

BACKGROUND

Breast cancer is the most commonly diagnosed cancer worldwide. Although major treatments represented by chemotherapy have shown effectiveness at the initial period, recurrence and metastasis still occur later after treatments. The alternation of the tumor microenvironment by chemotherapy is confirmed as a trigger of the elevated proliferation and migration of the remaining tumor cells.

METHODS

Using bioinformatic methods, differential gene expression analysis was used to determine DEGs between post-chemotherapy and pre-chemotherapy samples of breast cancer patients, followed by survival analysis and ELISA analysis of the potential key genes. An in vitro model of 2 breast cancer cells lines was used to demonstrate the role of VWF in the evasion and migration of breast cancer cells, using cell migration, evasion and wound healing assays, PCR and molecular docking analysis.

RESULTS

19 hub genes were further identified using GO and KEGG pathway analyses and WGCNA. The 5 secreted protein-coding genes with reported carcinogenesis effects (VWF, SVEP1, DPT, ADIPOQ, and LPL) were further analyzed in breast cancer patients and VWF was identified as a potential key regulator in the anthracycline-based chemotherapy-exacerbated metastasis. It was further confirmed that anthracycline-based chemotherapeutics doxorubicin exacerbated VWF upregulation and the evasion and migration of breast cancer cells. Based on molecular docking analysis and previous study, berberine was used as an inhibitor of VWF, and showed an effective inhibition of the doxorubicin-exacerbated VWF upregulation, migration and evasion in breast cancer.

CONCLUSIONS

Doxorubicin-exacerbated evasion and migration through VWF upregulation. Berberine as an inhibitor of VWF was able to reversed the doxorubicin-exacerbated VWF upregulation and evasion and migration in breast cancer cells.

miRNA-124 loaded extracellular vesicles encapsulated within hydrogel matrices for combating chemotherapy-induced neurodegeneration

Chemotherapy-induced neurodegeneration represents a significant challenge in cancer survivorship, manifesting in cognitive impairments that severely affect patients' quality of life. Emerging neuroregenerative therapies offer promise in mitigating these adverse effects, with miRNA-124 playing a pivotal role due to its critical functions in neural differentiation, neurogenesis, and neuroprotection. This review article delves into the innovative approach of using miRNA-124-loaded extracellular vesicles (EVs) encapsulated within hydrogel matrices as a targeted strategy for combating chemotherapy-induced neurodegeneration. We explore the biological underpinnings of miR-124 in neuroregeneration, detailing its mechanisms of action and therapeutic potential. The article further examines the roles and advantages of EVs as natural delivery systems for miRNAs and the application of hydrogel matrices in creating a sustained release environment conducive to neural tissue regeneration. By integrating these advanced materials and biological agents, we highlight a synergistic therapeutic strategy that leverages the bioactive properties of miR-124, the targeting capabilities of EVs, and the supportive framework of hydrogels. Preclinical studies and potential pathways to clinical translation are discussed, alongside the challenges, ethical considerations, and future directions in the field. This comprehensive review underscores the transformative potential of miR-124-loaded EVs in hydrogel matrices, offering insights into their development as a novel and integrative approach for addressing the complexities of chemotherapy-induced neurodegeneration.

Chemical compounds, anti-tumor and anti-neuropathic pain effect of hemp essential oil in vivo

Hemp (Cannabis sativa L.), an annual dioecious plant, has shown extensive application in the fields of fibers, food, oil, medicine, etc. Currently, most attention has been paid to the therapeutic properties of phytocannabinoids. However, the pharmaceutical research on essential oil from hemp is still lacking. In this study, hemp essential oil (HEO) was extracted from hemp flowers and leaves, and the components were analyzed by GC-MS. Quatitative analysis of three main compounds β-caryophyllene, β-caryophyllene oxide, α -humulene were determined by GC-FID. The anti-tumor and anti-neuropathic pain effects of HEO were evaluated. In the paclitaxel induced neuropathic mice model, HEO reduced the serum level of inflammatory cytokines TNF-α to achieve the analgesic effect, which was tested by evaluating mechanical and thermal hyperalgesia. Further investigation with cannabinoid receptor 2 (CB2 R) antagonist AM630 revealed the mechanism of reversing mechanical hyperalgesia may be related to CB2 R. In Lewis lung cancer grafted mice model, the tumor growth was significantly inhibited, the levels of tumor inflammatory cytokines TNF-α and IL-6 were downregulated, immune organ index was modified and immune-related CD4+, CD8+ T lymphocytes level, CD4+/CD8+ ratio were increased when administered with HEO. These results reveal that HEO plays a role not only in tumor chemotherapy induced peripheral neuropathy treatment, but also in anti-tumor treatment which offers key information for new strategies in cancer treatment and provides reference for the medicinal development of hemp.

Inhibition of Oxidative Stress and Related Signaling Pathways in Neuroprotection

Oxidative stress, characterized by increased production of reactive oxygen species (ROS) and disturbed redox homeostasis, is one of the key mechanisms underlying synaptic loss and neuronal death in various neurodegenerative diseases [...].

The Potential Antinociceptive Effect and Mechanism of Cannabis sativa L. Extract on Paclitaxel-Induced Neuropathic Pain in Rats Uncovered by Multi-Omics Analysis

Cannabis sativa L. (hemp) is a herbaceous plant rich in cannabinoids with a long history of use in pain treatment. The most well-characterized cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), garnered much attention in chemotherapy-induced peripheral neuropathy (CIPN) treatment. However, few studies have investigated the biological benefits and mechanism of hemp extract on CIPN. In the present study, hemp extract (JG) rich in cannabinoids was extracted by supercritical fluid carbon dioxide extraction (SFCE). The antinociceptive efficacy was evaluated using a paclitaxel-induced peripheral neuropathy (PIPN) rat model based on behavioral tests. Further omics-based approaches were applied to explore the potential mechanisms. The results showed that JG decreased mechanical allodynia, thermal hyperalgesia, and inflammatory cytokines in PIPN rats significantly. Transcriptome analysis identified seven key genes significantly regulated by JG in PIPN model rats, mainly related to the neuroactive ligand-receptor interaction pathway, PPAR signaling pathway, and cAMP signaling pathway. In metabolomic analysis, a total of 39 significantly altered metabolites were identified, mainly correlated with pentose and glucuronate interconversions and the glycerophospholipid metabolism pathway. Gut microbiota analysis suggested that increased community Lachnoclostridium and Lachnospiraceae_UCG-006 in PIPN rats can be reversed significantly by JG. In conclusion, hemp extract exhibited antinociceptive effects on PIPN. The analgesic mechanism was probably related to the regulation of inflammation, neuroactive ligand-receptor interaction pathway, sphingolipid metabolism, etc. This study provides novel insights into the functional interactions of Cannabis sativa L. extract on PIPN.

Anxiety in oncology outpatients is associated with perturbations in pathways identified in anxiety focused network pharmacology research

PURPOSE

Evaluate for perturbed signaling pathways associated with subgroups of patients with low versus high levels of state anxiety. These pathways were compared to the pathways identified across eight network pharmacology studies of the anxiolytic effect(s) of a variety of compounds.

METHODS

Adult outpatients had a diagnosis of breast, gastrointestinal, gynecological, or lung cancer; had received chemotherapy within the preceding four weeks; and were scheduled to receive at least two additional cycles of chemotherapy. Latent profile analysis was used to identify subgroups of patients with distinct anxiety profiles based on Spielberger State Anxiety Inventory scores that were obtained six times over two cycles of chemotherapy. Blood samples were processed using RNA sequencing (i.e., RNA-seq sample, n = 244) and microarray (i.e., microarray sample; n = 256) technologies. Pathway perturbations were assessed using pathway impact analysis. Fisher's combined probability method was used to combine test results using a false discovery rate of 0.01.

RESULTS

In the RNA-seq sample, 62.3% and 37.7% of the patients were in the low- and high-anxiety classes, respectively. In the microarray sample, 61.3% and 38.7% were in the low and high-anxiety classes, respectively. Forty-one perturbed signaling pathways were identified. Eight of these pathways were common to those identified in the network pharmacology studies.

CONCLUSIONS

Findings increase our knowledge of the molecular mechanisms that underlie anxiety in patients receiving chemotherapy. This study provides initial insights into how anxiety in patients with cancer may share common mechanisms with anxiety in patients with other clinical conditions.

Promoting AMPK/SR-A1-mediated clearance of HMGB1 attenuates chemotherapy-induced peripheral neuropathy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious side effect of chemotherapy with poorly understood mechanisms and few treatments. High-mobility group box 1 (HMGB1)-induced neuroinflammation is the main cause of CIPN. Here, we aimed to illustrate the role of the macrophage scavenger receptor A1 (SR-A1) in HMGB1 clearance and CIPN resolution.

METHODS

Oxaliplatin (L-OHP) was used to establish a CIPN model. Recombinant HMGB1 (rHMGB1) (his tag) was used to evaluate the phagocytosis of HMGB1 by macrophages.

RESULTS

In the clinic, HMGB1 expression and MMP-9 activity were increased in the plasma of patients with CIPN. Plasma HMGB1 expression was positively correlated with the cumulative dose of L-OHP and the visual analog scale. In vitro, engulfment and degradation of rHMGB1 increased and inflammatory factor expression decreased after AMP-activated protein kinase (AMPK) activation. Neutralizing antibodies, inhibitors, or knockout of SR-A1 abolished the effects of AMPK activation on rHMGB1 engulfment. In vivo, AMPK activation increased SR-A1 expression in the dorsal root ganglion, decreased plasma HMGB1 expression and MMP-9 activity, and attenuated CIPN, which was abolished by AMPK inhibition or SR-A1 knockout in the CIPN mice model.

CONCLUSION

Activation of the AMPK/SR-A1 axis alleviated CIPN by increasing macrophage-mediated HMGB1 engulfment and degradation. Therefore, promoting HMGB1 clearance may be a potential treatment strategy for CIPN. Video abstract.

The effect of doxorubicin or cyclophosphamide treatment on auditory brainstem response in mice

Clinical studies suggest that chemotherapy is associated with long-term cognitive impairment in some patients. Several underlying mechanisms have been proposed; however, the etiology of chemotherapy-related cognitive dysfunction remains relatively unknown. There is evidence that oligodendrocytes and white matter tracts within the CNS may be particularly vulnerable to chemotherapy-related damage and dysfunction. Auditory brainstem responses (ABRs) have been used to detect and measure functional integrity of myelin in a variety of animal models of autoimmune disorders and demyelinating diseases. Limited evidence suggests that increases in interpeak latencies, associated with disrupted impulse conduction, can be detected in ABRs following 5-fluorouracil administration in mice. It is unknown if similar functional disruptions can be detected following treatment with other chemotherapeutic compounds and the extent to which alterations in ABR signals represent robust and long-lasting impairments associated with chemotherapy-related cognitive impairment. Thus, C57BL/6 J mice were treated every 3rd day for a total of 3 injections with low or high dose cyclophosphamide, or doxorubicin. ABRs of mice were assessed on days 1, 7, 14, 56 and 6 months following completion of chemotherapy administration. There were timing and amplitude differences in the ABRs of the doxorubicin and the high dose cyclophosphamide groups relative to the control animals. However, despite significant toxic effects as assessed by weight loss, the changes in the ABR were transient.

Synergistic Antinociceptive Effects of Indomethacin-Pregabalin and Meloxicam-Pregabalin in Paclitaxel-Induced Neuropathic Pain

Neuropathic pain is often closely associated with nerve injury or inflammation, and the role of traditional nonsteroidal anti-inflammatory drugs as adjuvants for treating chemotherapy-induced peripheral neuropathic pain remains unclear. In this study, the potential synergistic antinociceptive effects of indomethacin–pregabalin and meloxicam–pregabalin were evaluated in paclitaxel-induced neuropathic pain and carrageenan-induced inflammatory pain in rodents. Although indomethacin and meloxicam alone only slightly relieved mechanical allodynia in the above two models, isobolographic analysis showed that the combination of indomethacin or meloxicam with pregabalin produced significant synergistic antinociceptive effects for paclitaxel-induced neuropathic pain (IN-PGB, experimental ED₂₅ = [4.41 (3.13–5.82)] mg/kg, theoretical ED₂₅ = [8.50 (6.62–10.32)] mg/kg; MEL-PGB, experimental ED₂₅ = [3.96 (2.62–5.46)] mg/kg, theoretical ED₂₅ = [7.52 (5.73–9.39)] mg/kg). In addition, MEL-PGB dosed via intraplantar injection into the left paw, intragastric injection, or intraperitoneal injection reversed paclitaxel-induced allodynia, indicating that they may act at multiple sites in the neuroaxis and periphery. However, indomethacin–pregabalin and meloxicam–pregabalin exerted antagonistic antiallodynic interactions in carrageenan-induced inflammatory pain in rats. Taken together, coadministration of indomethacin or meloxicam with pregabalin may possess potential therapeutic advantages for treating chemotherapy-induced neuropathic pain.

Cyclophosphamide and epirubicin induce high apoptosis in microglia cells while epirubicin provokes DNA damage and microglial activation at sub-lethal concentrations

Chemotherapy Related Cognitive Impairment (CRCI), also called chemobrain, diminishes cancer patient's life quality. Breast cancer (BC) patients have been described to be importantly affected, however, the mechanism leading to CRCI has not been fully elucidated. Recent research proposes microglia as the main architect of CRCI, thus dysregulations in these cells could trigger CRCI. The aim of this research was to evaluate the effects of two drugs commonly used against breast cancer, cyclophosphamide (CTX) and epirubicin (EPI), on the microglia cell line SIM-A9, using the BC cell line, 4T1, as a control. Our results show that CTX and EPI decrease microglia-cell viability and increase cell death on a concentration-dependent manner, being 5 and 2 times more cytotoxic to microglia cell line than to breast cancer 4T1cells, respectively. Both chemotherapies induce cell cycle arrest and a significant increase in p53, p16 and γ-H2AX in breast cancer and microglia cells. Furthermore, mitochondrial membrane potential (ΔΨm) diminishes as cell death increases, and both chemotherapies induce reactive oxygen species (ROS) production on SIM-A9 and 4T1. Moreover, caspase activation increases with treatments and its pharmacological blockade inhibits CTX and EPI induced-cell death. Finally, low concentrations of CTX and EPI induce γ-H2AX, and EPI induces cytokine release, NO production and Iba-1 overexpression. These findings indicate that microglia cells are more sensitive to CTX and EPI than BC cells and undergo DNA damage and cell cycle arrest at very low concentrations, moreover EPI induces microglia activation and a pro-inflammatory profile.

Exercise protocols: The gap between preclinical and clinical exercise oncology studies

Introduction

Preclinical studies provide foundational knowledge to develop new effective treatments for use in clinical practice. Similar to clinical exercise oncology studies, it is also important to monitor, identify and/or avoid cancer-induced complications in preclinical (e.g., murine) exercise oncology studies. This may help close the gap between preclinical and clinical exercise oncology studies. The aim of the present mini review is to provide insight into exercise protocol design in preclinical exercise oncology studies in order to close the preclinical-clinical gap. A secondary aim was to examine exercise-responsive outcomes in the preclinical versus clinical setting.

Method

We reviewed animal studies in exercise oncology. A literature search was performed in PubMed/Medline and studies in English were screened.

Results

We found that the majority of preclinical exercise protocols have not been at least tested clinically. We found some evidence that certain outcomes of preclinical studies (e.g., markers of cellular and molecular adaptation) that translate to clinical studies. However, this translation was dependent on the use, by investigators in their study design, of suitable and applicable preclinical exercise protocols.

Conclusions

Cancer and its treatment-induced complications (e.g., fatigue, cardiac atrophy, cachexia, etc.) have largely been ignored in the exercise protocols of preclinical oncology studies. Preclinical exercise oncology studies should consider the limitations of human exercise oncology studies when conducting gap analysis for their study design to increase the probability that findings related to mechanistic adaptations in exercise oncology will be translatable to the clinical setting. By virtue of paying heed to patient compliance and adverse effects, clinical exercise oncology research teams must design relevant, feasible exercise protocols; researchers in preclinical exercise oncology should also take such factors into consideration in order to help bridge the gap between preclinical and clinical studies in exercise oncology.

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Preclinical research provides foundational knowledge for the development of human experimental and clinical studies; however, direct translation of preclinical findings has a low success rate.

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Exercise can provide potent wide-ranging beneficial effects for people with chronic diseases, including cancer.

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A minority of preclinical exercise oncology studies account for cancer-related factors in their experimental design.

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To lessen the preclinical–clinical gap in exercise oncology research, preclinical exercise oncology studies should consider using experimental designs that are based on locomotor activity and/or VO2peak in animals bearing cancer.

Astaxanthin ameliorates damage to the cerebral cortex, hippocampus and cerebellar cortex caused by methotrexate

We investigated the ameliorating effects of astaxanthin (AXA) on methotrexate (MTX) induced damage to the cerebral cortex, hippocampus, cerebellar cortex and blood. We used 24 female Wistar albino rats divided into three groups of eight as follows: sham/control group, single dose of saline intraperitoneally (i.p.) and 7 days orally; MTX group, single dose of 20 mg/kg MTX (i.p.); MTX + AXA group, single dose of 20 mg/kg MTX i.p.+ 100 mg/kg AXA orally for 7 days. For all groups we measured total oxidant status (TOS) and total antioxidant status (TAS) in the cerebral cortex, hippocampus and blood. Histological sections of cerebral cortex, hippocampus and cerebellar cortex were inspected microscopically. Caspase-3 (cas-3), granulocyte colony-stimulating factor (GCSF), growth related oncogene (GRO), inducible nitric oxide synthase (iNOS) and myelin basic protein (MBP) were estimated immunohistochemically in the cerebral cortex, hippocampus and cerebellar cortex. In the MTX group, TAS was decreased significantly in the cerebral cortex, hippocampus and blood, while TOS was significantly increased. AXA significantly ameliorated oxidative stress parameters in the cerebral cortex and hippocampus. Histopathological examination revealed degeneration, edema and hyperemia in the cerebral cortex, hippocampus and cerebellar cortex in the MTX group. AXA treatment ameliorated histopathological changes. MTX decreased MBP expression in cerebral cortex. Although MBP expression was decreased in the cerebral cortex, hippocampus and cerebellar cortex stimulated with MTX, the expressions of cas-3, GCSF, GRO and iNOS were significantly increased. AXA ameliorated the expression of cas-3, GCSF, GRO, iNOS and MBP. AXA exhibits anti-inflammatory, antioxidant and anti-apoptotic effects on MTX induced toxicity in the cerebral cortex, hippocampus and cerebellar cortex by increasing MBP expression, regulating inflammatory cytokine release and reducing oxidative stress.

A Bibliometric Analysis of Cyclophosphamide, Methotrexate, and Fluorouracil Breast Cancer Treatments: Implication for the Role of Inflammation in Cognitive Dysfunction

Inflammation is considered one of the possible mechanisms behind long-term cognitive dysfunction persistent after chemotherapy treatment. The chemotherapy combination of cyclophosphamide, methotrexate, and fluorouracil (CMF) was one of the older methods of treating breast cancer patients. Decades later, these patients still report experiencing cognitive side effects. In this present bibliometric review, we applied the VOSviewer tool to describe the existing landscape on literature concerning inflammation as it relates to CMF and cognitive dysfunctions. As time progressed, we saw an increase in interest in the topic. By the mid-2010s there were approximately 1,000 publications per year. Terms related to the brain and CNS did not appear until the later years, and terms related to inflammation and breast cancer were very prevalent throughout the three decades. Also, in more recent years, inflammatory markers and plant-derived compounds used to alleviate side effects of the inflammatory response appeared in the search results. The USA remained the most prolific producer of CMF-, inflammation-, and cognitive dysfunction-related papers throughout the three decades followed by Asia and Europe. As research of cognitive dysfunction caused by inflammation due to chemotherapy treatment progresses, more opportunities emerge for therapeutic methods to improve the quality of life for long-term survivors.

Longitudinal study of inflammatory, behavioral, clinical, and psychosocial risk factors for chemotherapy-induced peripheral neuropathy

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting side effect of taxane and platinum chemotherapy for breast cancer. Clinicians cannot accurately predict CIPN severity partly because its pathophysiology is poorly understood. Although inflammation may play a role in CIPN, there are limited human studies. Here, we identified the strongest predictors of CIPN using variables measured before taxane- or platinum-based chemotherapy, including serum inflammatory markers.

METHODS

116 sedentary women with breast cancer (mean age 55 years) rated (1) numbness and tingling and (2) hot/coldness in hands/feet on 0-10 scales before and after 6 weeks of taxane- or platinum-based chemotherapy. A sub-study was added to collect cytokine data in the final 55 patients. We examined all linear models to predict CIPN severity at 6 weeks using pre-chemotherapy assessments of inflammatory, behavioral, clinical, and psychosocial factors. The final model was selected via goodness of fit.

RESULTS

The strongest pre-chemotherapy predictors of numbness and tingling were worse fatigue/anxiety/depression (explaining 27% of variance), older age (9%), and baseline neuropathy (5%). The strongest predictors of hot/coldness in hands/feet were worse baseline neuropathy (11%) and fatigue/anxiety/depression (6%). Inflammation was a risk for CIPN, per more pro-inflammatory IFN-γ (12%) and IL-1β (6%) and less anti-inflammatory IL-10 (6%) predicting numbness/tingling and more IFN-γ (17%) and less IL-10 (9%) predicting hot/coldness in hands/feet.

CONCLUSIONS

The strongest pre-chemotherapy predictors of CIPN included worse fatigue/anxiety/depression and baseline neuropathy. A pro-inflammatory state also predicted CIPN. Because this is an exploratory study, these results suggest specific outcomes (e.g., IL-1β) and effect size estimates for designing replication and extension studies.

CLINICAL TRIAL REGISTRATION

NCT00924651.

Life after Cell Death-Survival and Survivorship Following Chemotherapy

Simple Summary

Treatment of aggressive cancers often relies on chemotherapy. This treatment has improved survival rates, but while effective at killing cancer cells, inevitably it also kills or alters the function of others. While many of the known effects are transient and resolve after treatment, as survival rates increase, so does our understanding of the long-term health costs that accompany cancer survivors. Here we provide an overview of common long-term morbidities known to be caused by conventional chemotherapy, including the risk of relapse, but more importantly, the cost of quality of life experienced, especially by those who have cancer in early life. We aim to highlight the importance of the development of targeted therapies to replace the use of conventional chemotherapy, but also that of treating the patients along with the disease to enable not only longer but also healthier life after cancer.

Abstract

To prevent cancer cells replacing and outnumbering their functional somatic counterparts, the most effective solution is their removal. Classical treatments rely on surgical excision, chemical or physical damage to the cancer cells by conventional interventions such as chemo- and radiotherapy, to eliminate or reduce tumour burden. Cancer treatment has in the last two decades seen the advent of increasingly sophisticated therapeutic regimens aimed at selectively targeting cancer cells whilst sparing the remaining cells from severe loss of viability or function. These include small molecule inhibitors, monoclonal antibodies and a myriad of compounds that affect metabolism, angiogenesis or immunotherapy. Our increased knowledge of specific cancer types, stratified diagnoses, genetic and molecular profiling, and more refined treatment practices have improved overall survival in a significant number of patients. Increased survival, however, has also increased the incidence of associated challenges of chemotherapy-induced morbidity, with some pathologies developing several years after termination of treatment. Long-term care of cancer survivors must therefore become a focus in itself, such that along with prolonging life expectancy, treatments allow for improved quality of life.

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

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

Neuroimmune reactivity marker expression in rodent models of chemotherapy-induced cognitive impairment: A systematic scoping review

BACKGROUND

Chemotherapy-induced cognitive impairment (CICI) is a debilitating side effect arising from chemotherapy treatments. The condition is characterised by a range of cognitive deficits including impairment to memory, attention, and concentration. Whilst the underlying mechanisms that contribute to CICI remain unclear, neuroinflammation has been suggested as one key contributor.

METHOD

A comprehensive systematic search of EMBASE and Medline via PubMed was conducted to identify studies on neuroimmune reactivity marker expression changes and resulting cognitive changes in preclinical rodent models of CICI.

RESULTS

A total of twenty studies met the eligibility criteria and were included in the scoping review. There was significant heterogeneity in the methodology employed in the included studies. Our findings demonstrate that widespread changes in cytokines, chemokines, microglia reactivity, and astrocyte reactivity are observed in CICI in the brain regions expected to be affected, given the nature of the cognitive impairment observed in CICI.

CONCLUSIONS

Although there was considerable heterogeneity in study design that made comparisons between studies difficult, our findings suggest that neuroinflammation commonly occurs in CICI preclinical rodent models and shows an association with cognitive impairment.

Berberine inhibits chemotherapy-exacerbated ovarian cancer stem cell-like characteristics and metastasis through GLI1

Despite the remarkable clinical response in ovarian cancer therapy, the distinctively high metastasis rate is still a barrier to achieve satisfying prognosis. Our study aimed to decipher the role of berberine in inhibiting chemotherapy-exacerbated ovarian cancer metastasis. We found that chemotherapy exacerbated the migration and cancer stem cell (CSC)-like characteristics through transcriptional factor GLI1, which regulated the pluripotency-associated gene BMI1 and the epithelial-mesenchymal transition (EMT) markers Vimentin and Snail. Berberine could not only down-regulate CSC-like characteristics but also reverse EMT and migration through inhibiting chemotherapy-activated GLI1/BMI1 signaling pathway. Together, our study revealed the pivotal role of berberine in overcoming chemotherapy-exacerbated ovarian cancer metastasis, thereby provided a potential adjuvant therapeutic agent in combination with chemotherapeutics to prevent metastasis during ovarian cancer chemotherapy.

Chemotherapy exacerbates ovarian cancer cell migration and cancer stem cell-like characteristics through GLI1

BACKGROUND

Despite the great clinical response to the first-line chemotherapeutics, metastasis still happens among most of the ovarian cancer patients within 2 years.

METHODS

Using multiple human ovarian cancer cell lines, a transwell co-culture system of the carboplatin or VP-16-challenged feeder and receptor cells was established to demonstrate the chemotherapy-exacerbated migration. The migration and cancer stem cell (CSC)-like characteristics were determined by wound healing, transwell migration, flow cytometry and sphere formation. mRNA and protein expression were identified by qPCR and western blot. Bioinformatics analysis was used to investigate the differentially expressed genes. GLI1 expression in tissue samples was analysed by immunohistochemistry.

RESULTS

Chemotherapy was found to not only kill tumour cells, but also trigger the induction of CSC-like traits and the migration of ovarian cancer cells. EMT markers Vimentin and Snail in receptor cells were upregulated in the microenvironment of chemotherapy-challenged feeder cells. The transcription factor GLI1 was upregulated by chemotherapy in both clinical samples and cell lines. Follow-up functional experiments illustrated that inhibiting GLI1 reversed the chemotherapy-exacerbated CSC-like traits, including CD44 and CD133, as well as prevented the migration of ovarian cancer cells.

CONCLUSIONS

Targeting GLI1 may improve clinical benefits in the chemotherapy-exacerbated metastasis in ovarian cancer treatment.

Visual Pathway Degeneration in Chemotherapy-Related Neurotoxicity: A Review and Directions for Future Research

Chemotherapy-related neurotoxicity (CRNT) is an emerging public health concern. Visual pathway degeneration may be a symptom of CRNT. We surveyed the current literature for evidence of visual pathway degeneration in cancer patients receiving chemotherapy. A systematic review was conducted in PubMed. Six published articles met our inclusion criteria. The studies showed reduced retinal thickness, primarily in the retinal nerve fibre layer, and impaired inner retinal function in patients receiving chemotherapy. In summary, the current literature suggests chemotherapy may induce visual pathway degeneration. Future research may benefit from improving study design, exploring mechanisms of chemotherapy-related visual pathway degeneration, and incorporating these findings into biomarker development.

Systemic loss of Sarm1 protects Schwann cells from chemotoxicity by delaying axon degeneration

Protecting the nervous system from chronic effects of physical and chemical stress is a pressing clinical challenge. The obligate pro-degenerative protein Sarm1 is essential for Wallerian axon degeneration. Thus, blocking Sarm1 function is emerging as a promising neuroprotective strategy with therapeutic relevance. Yet, the conditions that will most benefit from inhibiting Sarm1 remain undefined. Here we combine genome engineering, pharmacology and high-resolution intravital videmicroscopy in zebrafish to show that genetic elimination of Sarm1 increases Schwann-cell resistance to toxicity by diverse chemotherapeutic agents after axonal injury. Synthetic degradation of Sarm1-deficient axons reversed this effect, suggesting that glioprotection is a non-autonomous effect of delayed axon degeneration. Moreover, loss of Sarm1 does not affect macrophage recruitment to nerve-wound microenvironment, injury resolution, or neural-circuit repair. These findings anticipate that interventions aimed at inhibiting Sarm1 can counter heightened glial vulnerability to chemical stressors and may be an effective strategy to reduce chronic consequences of neurotrauma.

An infection of Enterobacter ludwigii affects development and causes age-dependent neurodegeneration in Drosophila melanogaster

The effects of teeth-blackening bacteria Enterobacter ludwigii on the physiological system were investigated using the model organism Drosophila melanogaster. The bacteria were mixed with the fly food, and its effect was checked on the growth, development and behaviour of Drosophila. Microbes generate reactive oxygen species (ROS) within the haemolymph of the larvae once it enters into the body. The increased amount of ROS was evidenced by the NBT assay and using 2',7'-dichlorofluorescin diacetate dye, which indicates the mitochondrial ROS. The increased amount of ROS resulted in a number of abnormal nuclei within the gut. Besides that larvae walking became sluggish in comparison with wild type although the larvae crawling path did not change much. Flies hatched from the infectious larvae have the posterior scutellar bristle absent from the thorax and abnormal mechanosensory hairs in the eye, and they undergo time-dependent neurodegeneration as evidenced by the geotrophic and phototrophic assays. To decipher the mechanism of neurodegeneration, flies were checked for the presence of four important bioamines: tyramine, cadaverine, putrescine and histamine. Out of these four, histamine was found to be absent in infected flies. Histamine is a key molecule required for the functioning of the photoreceptor as well as mechanoreceptors. The mechanism via which mouth infectious bacteria E. ludwigii can affect the development and cause age-dependent neurodegeneration is explained in this paper.