microRNA-329 reduces bone cancer pain through the LPAR1-dependent LPAR1/ERK signal transduction pathway in mice

Unveiling the therapeutic promise: exploring Lysophosphatidic Acid (LPA) signaling in malignant bone tumors for novel cancer treatments

Malignant bone tumors, including primary bone cancer and metastatic bone tumors, are a significant clinical challenge due to their high frequency of presentation, poor prognosis and lack of effective treatments and therapies. Bone tumors are often accompanied by skeletal complications such as bone destruction and cancer-induced bone pain. However, the mechanisms involved in bone cancer progression, bone metastasis and skeletal complications remain unclear. Lysophosphatidic acid (LPA), an intercellular lipid signaling molecule that exerts a wide range of biological effects mainly through specifically binding to LPA receptors (LPARs), has been found to be present at high levels in the ascites of bone tumor patients. Numerous studies have suggested that LPA plays a role in primary malignant bone tumors, bone metastasis, and skeletal complications. In this review, we summarize the role of LPA signaling in primary bone cancer, bone metastasis and skeletal complications. Modulating LPA signaling may represent a novel avenue for future therapeutic treatments for bone cancer, potentially improving patient prognosis and quality of life.

METTL14-mediated m6A epitranscriptomic modification contributes to chemotherapy-induced neuropathic pain by stabilizing GluN2A expression via IGF2BP2

Epigenetics is a biological process that modifies and regulates gene expression, affects neuronal function, and contributes to pain. However, the mechanism by which epigenetics facilitates and maintains chronic pain is poorly understood. We aimed to determine whether N6-methyladenosine (m6A) specifically modified by methyltransferase-like 14 (METTL14) alters neuronal activity and governs pain by sensitizing the GluN2A subunit of the N-methyl-d-aspartate receptor (NMDAR) in the dorsal root ganglion (DRG) neurons in a model of chemotherapy-induced neuropathic pain (CINP). Using dot blotting, immunofluorescence, gain/loss-of-function, and behavioral assays, we found that m6A levels were upregulated in L4-L6 DRG neurons in CINP in a DBP/METTL14-dependent manner, which was also confirmed in human DRGs. Blocking METTL14 reduced m6A methylation and attenuated pain hypersensitivity. Mechanistically, METTL14-mediated m6A modification facilitated the synaptic plasticity of DRG neurons by enhancing the GluN2A subunit of NMDAR, and inhibiting METTL14 blocked this effect. In contrast, overexpression of METTL14 upregulated m6A modifications, enhanced presynaptic NMDAR activity in DRG neurons, and facilitated pain sensation. Our findings reveal a previously unrecognized mechanism of METTL14-mediated m6A modification in DRG neurons to maintain neuropathic pain. Targeting these molecules may provide a new strategy for pain treatment.

LncRNA NCK1-AS1-mediated regulatory functions in human diseases

Disease development requires the activation of complex multi-factor processes involving numerous long noncoding RNAs (lncRNAs), which describe non-protein-coding RNAs longer than 200 nucleotides. Emerging evidence indicates that lncRNAs act as essential regulators that perform pivotal roles in the pathogenesis and progression of human diseases. The mechanisms underlying lncRNA involvement in diverse diseases have been extensively explored, and lncRNAs are considered powerful biomarkers for clinical practice. The lncRNA noncatalytic region of tyrosine kinase adaptor protein 1 (NCK1) antisense 1 (NCK1-AS1), also known as NCK1 divergent transcript (NCK1-DT), is encoded on human chromosome 3q22.3 and produces a 27,274-base-long transcript. NCK1-AS1 has increasingly been characterized as a causative agent for multiple diseases. The abnormal expression and involvement of NCK1-AS1 in various biological processes have been associated with several diseases. Further exploration of the mechanisms through which NCK1-AS1 contributes to disease development and progression will provide a foundation for potential clinical applications of NCK1-AS1 in the diagnosis and treatment of various diseases. This review summarizes the current understanding of the various functions and mechanisms through which NCK1-AS1 contributes to various diseases and the clinical application prospects for NCK1-AS1.

Molecular Influence of Resiniferatoxin on the Urinary Bladder Wall Based on Differential Gene Expression Profiling

Resiniferatoxin (RTX) is a potent capsaicin analog used as a drug for experimental therapy to treat neurogenic disorders associated with enhanced nociceptive transmission, including lower urinary tract symptoms. The present study, for the first time, investigated the transcriptomic profile of control and RTX-treated porcine urinary bladder walls. We applied multistep bioinformatics and discovered 129 differentially expressed genes (DEGs): 54 upregulated and 75 downregulated. Metabolic pathways analysis revealed five significant Kyoto Encyclopedia of Genes and Genomes (KEGG) items ('folate biosynthesis', 'metabolic pathways', 'sulfur relay system', 'sulfur metabolism' and 'serotonergic synapse') that were altered after RTX intravesical administration. A thorough analysis of the detected DEGs indicated that RTX treatment influenced the signaling pathways regulating nerve growth, myelination, axon specification, and elongation. Many of the revealed DEGs are involved in the nerve degeneration process; however, some of them were implicated in the initiation of neuroprotective mechanisms. Interestingly, RTX intravesical installation was followed by changes in the expression of genes involved in synaptic plasticity and neuromodulation, including 5-HT, H2S, glutamate, and GABA transmission. The obtained results suggest that the toxin may exert a therapeutic, antinociceptive effect not only by acting on TRPV1 receptors.

Upregulation of Spinal miR-155-5p Contributes to Mechanical Hyperalgesia by Promoting Inflammatory Activation of Microglia in Bone Cancer Pain Rats

Bone cancer pain (BCP) seriously deteriorates the life quality of patients, but its underlying mechanism is still unclear. Spinal microRNAs might contribute to the development of BCP and the role of microglial activation is controversial. In this study, we established a BCP model by injecting Walker 256 breast carcinoma cells into the tibial intramedullary cavity of rats and significant hyperalgesia was observed in the BCP rats. The lumbar spinal cords were harvested to perform RNA sequencing (RNA-seq), and 31 differentially expressed miRNAs (26 upregulated and 5 downregulated) were identified in the BCP rats. Among them, miR-155-5p was significantly upregulated in the BCP rats. Spinal microglial activation was observed during BCP development. miR-155-5p could be expressed in spinal microglia and was significantly upregulated in microglia treated with lipopolysaccharide (LPS) in vitro. Serum/glucocorticoid regulated kinase family member 3 (Sgk3) was predicted to be the possible downstream target of miR-155-5p and this was confirmed using a dual-luciferase reporter assay in vitro. The inhibition of miR-155-5p restored Sgk3-expression-attenuated microglial activation and alleviated hyperalgesia in the BCP rats. In conclusion, spinal miR-155-5p/Sgk3/microglial activation might play an important role in BCP pathogenesis.

Chemopreventive and hepatoprotective effects of genistein via inhibition of oxidative stress and the versican/PDGF/PKC signaling pathway in experimentally induced hepatocellular carcinoma in rats by thioacetamide

Objective

Genistein is a recognized isoflavone present in soybeans with antioxidant, anti-inflammatory, antiangiogenic and antitumor activities. This study aimed to test ability of genistein in modulating versican/platelet derived growth factor (PDGF) axis in HCC.

Methods

HCC was experimentally induced in male Sprague-Dawley rats then treated with 25 or 75 mg/kg genistein. Antioxidant activities of genistein was assessed by measuring the gene expression of Nrf2 and the hepatic levels of malondialdehyde (MDA), superoxide dismutase (SOD) and reduced glutathione. Expression of versican, PDGF, protein kinase C (PKC) and ERK-1 protein was assessed by Western blotting and immunostaining.

Results

HCC induced an elevation in oxidative stress, PDGF, versican, PKC and ERK protein expression levels. Genistein significantly reduced an HCC-induced increase in oxidative stress. Moreover, genistein dose-dependently reduced HCC-induced elevation of PDGF, versican, PKC and ERK protein expression levels. Moreover, genistein helped retain a normal hepatocyte structure and reduced fibrous tissue deposition, especially in high dose.

Conclusions

Genistein exerted antitumor and antioxidant effects and therefore suppress HCC development via inhibition of the PDGF/versican bidirectional axis, suppressing both ERK1 and PKC as downstream regulators. Therefore, genistein is a potential novel therapeutic candidate for improving the outcome of patients with HCC.

microRNA-Based Network and Pathway Analysis for Neuropathic Pain in Rodent Models

Neuropathic pain (NP) is poorly managed, and in-depth mechanisms of gene transcriptome alterations in NP pathogenesis are not yet fully understood. To determine microRNA-related molecular mechanisms of NP and their transcriptional regulation in NP, PubMed, Embase, Web of Science and CINAHL Complete (EBSCO) were searched from inception to April 2021. Commonly dysregulated miRNAs in NP were assessed. The putative targets of these miRNAs were determined using TargetScan, Funrich, Cytoscape and String database. A total of 133 literatures containing miRNA profiles studies and experimentally verify studies were included. Venn analysis, target gene prediction analysis and functional enrichment analysis indicated several miRNAs (miR-200b-3p, miR-96, miR-182, miR-183, miR-30b, miR-155 and miR-145) and their target genes involved in known relevant pathways for NP. Targets on transient receptor potential channels, voltage-gated sodium channels and voltage-gated calcium channels may be harnessed for pain relief. A further delineation of signal processing and modulation in neuronal ensembles is key to achieving therapeutic success in future studies.

LncRNA PCAT19 Regulates Neuropathic Pain via Regulation of miR-182-5p/JMJD1A in a Rat Model of Chronic Constriction Injury

INTRODUCTION

Neuropathic pain (NP) is one of the most severe chronic pain types. In recent years, more and more studies have shown that long noncoding RNA (LncRNA) plays a key role in a variety of human diseases, including NP. However, the role of LncRNA prostate cancer-associated transcript 19 (PCAT19) in NP and its specific mechanism remain unclear.

METHODS

A chronic constrictive injury (CCI) rat model was established. Rat paw withdrawal threshold and paw withdrawal latency were used to evaluate the neuronal pain behavior of rats in this model. mRNA expression of PCAT19, neuroinflammatory factor, microRNA (miR)-182-5p, and Jumonji domain containing 1A (JMJD1A) were detected by quantitative real-time PCR. ELISA analysis was used to detect inflammatory factor protein expression. Dual-luciferase reporter assay was used to evaluate the targeting relationship between genes.

RESULTS

PCAT19 was continuously upregulated in CCI rats. miR-182-5p was the target of PCAT19, and miR-182-5p was increased after PCAT19 knockdown. NP behaviors such as mechanical ectopic pain and thermal hyperalgesia as well as neuroinflammation can be reduced by knocking down PCAT19. However, the injection of miR-182-5p antagomir significantly reversed the level of the NP behaviors and neuroinflammation caused by PCAT19 knockdown. Besides, dual-luciferase reporter assay showed that JMJD1A was the target gene of miR-182-5p. The level of JMJD1A in CCI rats increased with time. After PCAT19 knockdown, JMJD1A was significantly decreased, but inhibition of miR-182-5p can reverse its levels.

CONCLUSION

This study shows that PCAT19 plays a role in NP by targeting the miR-182-5p/JMJD1A axis, and PCAT19 can be used as a new therapeutic target for NP.

Analysis of primary nursing intervention for elderly patients with cancer pain on the improvement of potential risk and pain degree

OBJECTIVE

To analyze the effect of primary nursing on the improvement of potential risk and pain degree in elderly patients with cancer pain.

METHODS

Altogether 187 patients with cancer pain from June 2018 to November 2019 were selected as the research participants and grouped into two groups according to different nursing intervention methods, including 102 cases in the research group (RG) and 85 cases in the control group (CG). The pain relief and medication compliance were evaluated. General Self-efficacy Scale (GSES) and Exercise of Self-Care Agency (ESCA) were used to evaluate the self-efficacy and self-care ability. Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) were used to evaluate the anxiety and depression. Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. SF-36 Quality of Life Scale was used to evaluate the quality of life. Self-made nursing satisfaction questionnaire was used to evaluate the nursing satisfaction.

RESULTS

The improvement of pain relief in the RG was evidently higher than that in the CG. The scores of SAS and SDS in the RG after intervention were evidently lower than those in the CG. GSES and ESCA scores of patients in the RG after intervention were evidently higher than those in the CG. The compliance of patients in the RG after intervention was evidently higher than that in the CG. The PSQI scores of patients in the RG after intervention were evidently better than those in the CG. The scores of SF-36 and nursing satisfaction in the RG were evidently higher than those in the CG.

CONCLUSION

The implementation of primary nursing intervention for elderly patients with cancer pain can effectively relieve their pain and improve their bad psychological state and medication compliance, thus improving patients' quality of life.

MiR-135-5p Alleviates Bone Cancer Pain by Regulating Astrocyte-Mediated Neuroinflammation in Spinal Cord through JAK2/STAT3 Signaling Pathway

Bone cancer pain (BCP) was associated with microRNA dysregulation. In this study, we intended to clarify the potential role of miR-135-5p in a BCP mouse model, which was established by tumor cell implantation (TCI) in the medullary cavity of the mouse femur. The BCP-related behaviors were tested, including the paw withdrawal mechanical threshold (PWMT) and number of spontaneous flinches (NSF). The miRNA expression profiles in astrocytes of the sham and tumor groups were compared, and miRNA microarray and quantitative real-time PCR (qRT-PCR) assays confirmed that the amount of expression of miR-135-5p was significantly decreased in astrocytes of the tumor group. Gain- and loss-of-function studies showed that miR-135-5p could inhibit astrocyte activation and inflammation cytokine (TNF-α and IL-1β) expression. The relation between miR-135-5p and JAK2 was detected by bioinformatic analysis and dual luciferase reporter gene assay. By conducting in vitro experiments, it was shown that the miR-135-5P mimics lowered the level of JAK2/STAT3 proteins and inflammatory factors in astrocytes. Moreover, in vivo analysis on BCP mice model indicated that the miR-135-5p agonist could sufficiently increase PWMT and decrease NSF. Meanwhile, reduced activation of astrocytes in the spinal cord, as well as decreased expression of JAK2/STAT3 and inflammatory mediators, were found after miR-135-5p agonist treatment. Collectively, the results showed that miR-135-5p could potentially reduce BCP in mice through inhibiting astrocyte-mediated neuroinflammation and blocking of the JAK2/STAT3 signaling pathway, indicating that the upregulation of miR-135-5P could be a therapeutic focus in BCP treatment.

An Investigation of the Molecular Mechanisms Underlying the Analgesic Effect of Jakyak-Gamcho Decoction: A Network Pharmacology Study

Herbal drugs have drawn substantial interest as effective analgesic agents; however, their therapeutic mechanisms remain to be fully understood. To address this question, we performed a network pharmacology study to explore the system-level mechanisms that underlie the analgesic activity of Jakyak-Gamcho decoction (JGd; Shaoyao-Gancao-Tang in Chinese and Shakuyaku-Kanzo-To in Japanese), an herbal prescription consisting of Paeonia lactiflora Pallas and Glycyrrhiza uralensis Fischer. Based on comprehensive information regarding the pharmacological and chemical properties of the herbal constituents of JGd, we identified 57 active chemical compounds and their 70 pain-associated targets. The JGd targets were determined to be involved in the regulation of diverse biological activities as follows: calcium- and cytokine-mediated signalings, calcium ion concentration and homeostasis, cellular behaviors of muscle and neuronal cells, inflammatory response, and response to chemical, cytokine, drug, and oxidative stress. The targets were further enriched in various pain-associated signalings, including the PI3K-Akt, estrogen, ErbB, neurotrophin, neuroactive ligand-receptor interaction, HIF-1, serotonergic synapse, JAK-STAT, and cAMP pathways. Thus, these data provide a systematic basis to understand the molecular mechanisms underlying the analgesic activity of herbal drugs.