Chronic Cancer Pain: Opioids within Tumor Microenvironment Affect Neuroinflammation, Tumor and Pain Evolution

Cutting-edge nanotechnology: unveiling the role of zinc oxide nanoparticles in combating deadly gastrointestinal tumors

Zinc oxide nanoparticles (ZnO-NPs) have gained significant attention in cancer therapy due to their unique physical and chemical properties, particularly in treating gastrointestinal (GI) cancers such as gastric, colorectal, and hepatocellular carcinoma. These nanoparticles generate reactive oxygen species (ROS) upon entering cancer cells, causing oxidative stress that leads to cellular damage, DNA fragmentation, and apoptosis. ZnO-NPs affect the expression of key proteins involved in apoptosis, including p53, Bax, and Bcl-2, which regulate cell cycle arrest and programmed cell death. Additionally, ZnO-NPs can reduce mitochondrial membrane potential, further enhancing apoptosis in cancer cells. Furthermore, ZnO-NPs inhibit cancer cell proliferation by interfering with cell cycle progression. They reduce levels of cyclins and cyclin-dependent kinases (CDKs), leading to cell cycle arrest. ZnO-NPs also exhibit anti-metastatic properties by inhibiting the migration and invasion of cancer cells through modulation of signaling pathways that affect cell adhesion and cytoskeletal dynamics. The efficacy of ZnO-NPs in overcoming chemotherapy resistance has been demonstrated by their ability to reduce the IC50 values of chemotherapeutic agents, making cancer cells more susceptible to drug-induced cell death. In this review, we summarize the mechanisms by which ZnO-NPs exert anticancer effects in GI cancers, focusing on apoptosis, cell cycle regulation, and metastasis inhibition, while also highlighting the current limitations in translating these findings into effective clinical treatments.

ZC3H15 suppression ameliorates bone cancer pain through inhibiting neuronal oxidative stress and microglial inflammation

BACKGROUND

Patients with advanced-stage malignancies often endure unbearable pain, partly due to the incomplete understanding of its molecular mechanisms. Zinc finger CCCH-type containing 15 (ZC3H15) is a highly conserved eukaryotic protein involved in various cellular processes, including tumor growth and inflammation. However, its impact on cancer-induced pain, especially the underlying mechanisms, remains largely unknown.

METHODS

To evaluate the expression of ZC3H15 in cancer-induced pain, we used microcomputed tomography (MicroCT), immunoblotting, co-immunoprecipitation (Co-IP), behavior tests, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence assays in this investigation. Additionally, we used CCK8, cloning, and migration tests to examine the proliferation and migration of cancer cells. We also used transplantation tumor mouse model to investigate the course of the cancer cell growth. Finally, we looked into the biological processes linked to ZC3H15 using in vivo and in vitro ubiquitination detection, which was later verified.

RESULTS

In this study, we established a bone cancer pain (BCP) murine mouse model that impairs patients' quality of life. Initially, we observed a significant increase in the expression of ZC3H15 in dorsal horn spinal cord tissues of BCP mice, along with severe oxidative stress and inflammation. Subsequently, we found that adeno-associated virus (AAV) expressing ZC3H15 short hairpin RNA (shRNA) (AAV-shZC3H15) to silence ZC3H15 in vivo significantly alleviated the progression of BCP in mice, improving nociceptive behaviors, independent of tumor burden and bone destruction. Subsequently, we made a novel discovery that ZC3H15 knockdown mice with BCP displayed improved neuronal oxidative stress and reactive oxygen species (ROS) generation in spinal cord tissues, which was confirmed in H2O2-treated mouse spinal cord neurons primarily through mediating the kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor, erythroid 2-like transcription factor 2 (NRF2) pathway. Mechanistically, immunoblotting analysis revealed that ZC3H15 could maintain KEAP1 stability and thereby promote NRF2 ubiquitination and degradation under oxidative stress. Furthermore, the suppression of oxidative damage in neurons by ZC3H15 knockdown was significantly abolished upon the deletion of NRF2 expression, identifying the necessity of NRF2 for ZC3H15 in the mediation of BCP progression. Additionally, microglial activation and inflammatory response in spinal cord tissues of BCP mice were also attenuated by AAV-shZC3H15, which was verified in LPS-treated microglial cells in vitro by blocking the inhibitory protein κBα (IκBα)/nuclear factor κB (NF-κB) signaling pathway.

CONCLUSIONS

Our results provide evidence that suppressing ZC3H15 can alleviate BCP by restricting neuronal oxidative stress and microglial activation, contributing to the improvement of nociceptive behaviors. Therefore, we concluded that ZC3H15 may be a potential target for the management of BCP.

Understanding the Physiopathology of Pain Pathways for a Practical Approach of Cancer Pain Management

Pain associated with cancer is often the first symptom reported with major repercussions on patient's quality of life. Mechanical compression, release of algogenic substances by the tumor or the complications of oncologic treatment represent the major causes. Nociceptive and neuropathic pain are both induced by different mediators that give rise to a neuroinflammation creating a peripheral and central sensitization responsible of chronic pain. Understanding the pain pathway may orientate to the most appropriate treatment. Oral medication should be often reevaluated to consider multimodal analgesia including interventional pain procedures with intrathecal therapy and neuromodulation.

Impact of opioids and mu-opioid receptors on oncologic metastasis

Opioids are the most effective and widely used treatments for acute and chronic pain in patients with cancer. This review focuses on the impact of opioids and mu-opioid receptors (MORs) on the stages of oncologic metastasis. Studies have shown that opioids can facilitate tumor progression and are related to a poor prognosis in patients with cancer. As the primary receptor for opioids, MORs play a significant role in regulating malignant tumor transformation and are involved in processes, such as proliferation, angiogenesis, epithelial-mesenchymal transition (EMT), circulating tumor cells (CTCs) and the tumor microenvironment (TME). While clinical trials have investigated the relationship between opioids and patient prognosis, further research is needed to clarify the relationship between opioids, MORs and metastasis.

Pain Management in Animals with Oncological Disease: Opioids as Influencers of Immune and Tumor Cellular Balance

Advancements in understanding pain physiopathology have historically challenged animals' absence of pain senses. Studies have demonstrated that animals have comparable neural pain pathways, suggesting that cats and dogs likely experience pain similarly to humans. Understanding brain circuits for effective pain control has been crucial to adjusting pain management to the patient's individual responses and current condition. The refinement of analgesic strategies is necessary to better cater to the patient's demands. Cancer pain management searches to ascertain analgesic protocols that enhance patient well-being by minimizing or abolishing pain and reducing its impact on the immune system and cancer cells. Due to their ability to reduce nerve sensitivity, opioids are the mainstay for managing moderate and severe acute pain; however, despite their association with tumor progression, specific opioid agents have immune-protective properties and are considered safe alternatives to analgesia for cancer patients.

Opioids and Cancer: Current Understanding and Clinical Considerations

Pain is one of the most common symptoms in patients with cancer. Pain not only negatively affects the quality of life of patients with cancer, but it has also been associated with reduced survival. Pain management is therefore a critical component of cancer care. Prescription opioids remain the first-line approach for the management of moderate-to-severe pain associated with cancer. However, there has been increasing interest in understanding whether these analgesics could impact cancer progression. Furthermore, epidemiological data link a possible association between prescription opioid usage and cancer development. Until more robust evidence is available, patients with cancer with moderate-to-severe pain may receive opioids to decrease suffering. However, future studies should be conducted to evaluate the role of opioids and opioid receptors in specific cancers.

Application of Patient-Reported Outcome Measurements in Adult Tumor Clinical Trials in China: Cross-Sectional Study

BACKGROUND

International health policies and researchers have emphasized the value of evaluating patient-reported outcomes (PROs) in clinical studies. However, the characteristics of PROs in adult tumor clinical trials in China remain insufficiently elucidated.

OBJECTIVE

This study aims to assess the application and characteristics of PRO instruments as primary or secondary outcomes in adult randomized clinical trials related to tumors in China.

METHODS

This cross-sectional study identified tumor-focused randomized clinical trials conducted in China between January 1, 2010, and June 30, 2022. The ClinicalTrials.gov database and the Chinese Clinical Trial Registry were selected as the databases. Trials were classified into four groups based on the use of PRO instruments: (1) trials listing PRO instruments as primary outcomes, (2) trials listing PRO instruments as secondary outcomes, (3) trials listing PRO instruments as coprimary outcomes, and (4) trials without any mention of PRO instruments. Pertinent data, including study phase, settings, geographic regions, centers, participant demographics (age and sex), funding sources, intervention types, target diseases, and the names of PRO instruments, were extracted from these trials. The target diseases involved in the trials were grouped according to the American Joint Committee on Cancer Staging Manual, 8th Edition.

RESULTS

Among the 6445 trials examined, 2390 (37.08%) incorporated PRO instruments as part of their outcomes. Within this subset, 26.82% (641/2390) listed PRO instruments as primary outcomes, 52.72% (1260/2390) as secondary outcomes, and 20.46% (489/2390) as coprimary outcomes. Among the 2,155,306 participants included in these trials, PRO instruments were used to collect data from 613,648 (28.47%) patients as primary or secondary outcomes and from 74,287 (3.45%) patients as coprimary outcomes. The most common conditions explicitly using specified PRO instruments included thorax tumors (217/1280, 16.95%), breast tumors (176/1280, 13.75%), and lower gastrointestinal tract tumors (173/1280, 13.52%). Frequently used PRO instruments included the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire-30, the visual analog scale, the numeric rating scale, the Traditional Chinese Medicine Symptom Scale, and the Pittsburgh Sleep Quality Index.

CONCLUSIONS

Over recent years, the incorporation of PROs has demonstrated an upward trajectory in adult randomized clinical trials on tumors in China. Nonetheless, the infrequent measurement of the patient's voice remains noteworthy. Disease-specific PRO instruments should be more effectively incorporated into various tumor disease categories in clinical trials, and there is room for improvement in the inclusion of PRO instruments as clinical trial end points.

Osteosarcoma-Induced Pain Is Mediated by Glial Cell Activation in the Spinal Dorsal Horn, but Not Capsaicin-Sensitive Nociceptive Neurons: A Complex Functional and Morphological Characterization in Mice

Bone cancer and its related chronic pain are huge clinical problems since the available drugs are often ineffective or cannot be used long term due to a broad range of side effects. The mechanisms, mediators and targets need to be identified to determine potential novel therapies. Here, we characterize a mouse bone cancer model induced by intratibial injection of K7M2 osteosarcoma cells using an integrative approach and investigate the role of capsaicin-sensitive peptidergic sensory nerves. The mechanical pain threshold was assessed by dynamic plantar aesthesiometry, limb loading by dynamic weight bearing, spontaneous pain-related behaviors via observation, knee diameter with a digital caliper, and structural changes by micro-CT and glia cell activation by immunohistochemistry in BALB/c mice of both sexes. Capsaicin-sensitive peptidergic sensory neurons were defunctionalized by systemic pretreatment with a high dose of the transient receptor potential vanilloid 1 (TRPV1) agonist resiniferatoxin (RTX). During the 14- and 28-day experiments, weight bearing on the affected limb and the paw mechanonociceptive thresholds significantly decreased, demonstrating secondary mechanical hyperalgesia. Signs of spontaneous pain and osteoplastic bone remodeling were detected both in male and female mice without any sex differences. Microglia activation was shown by the increased ionized calcium-binding adapter molecule 1 (Iba1) immunopositivity on day 14 and astrocyte activation by the enhanced glial fibrillary acidic protein (GFAP)-positive cell density on day 28 in the ipsilateral spinal dorsal horn. Interestingly, defunctionalization of the capsaicin-sensitive afferents representing approximately 2/3 of the nociceptive fibers did not alter any functional parameters. Here, we provide the first complex functional and morphological characterization of the K7M2 mouse osteosarcoma model. Bone-cancer-related chronic pain and hyperalgesia are likely to be mediated by central sensitization involving neuroinflammation via glial cell activation in the spinal dorsal horn, but not the capsaicin-sensitive sensory neuronal system.

A novel investigation into the negative impact of opioid use on the efficacy of immune checkpoint inhibitors in advanced non-small cell lung cancer patients

OBJECTIVE

Immune checkpoint inhibitors (ICIs) have effectively improved the clinical outcome of advanced non-small cell lung cancer (NSCLC). Opioids are commonly used for pain relief in cancer patients. This study aims to clarify the prognostic impact of opioid use in advanced NSCLC patients receiving ICI therapy.

METHODS

A systematic literature review was carried out using online databases before July 2023. The meta-analysis was used to clarify the correlation of opioid use with the overall survival (OS) or progression-free survival (PFS) of ICI-treated NSCLC patients, both of which were determined using hazard ratios (HRs) coupled with 95 % confidence intervals (CIs). Then, an independent cohort enrolling 181 NSCLC patients was utilized for validation. Finally, a comprehensive bioinformatics analysis based on TCGA cohort was performed to investigate the prognostic significance of opioid target genes (OTGs) and their correlation with immune infiltration in NSCLC patients.

RESULTS

A total of 8 studies enrolling 1174 patients were included in the meta-analysis. Opioid use was negatively associated with worse PFS (HR = 2.16, 95 %CI: 1.26-3.71) and OS (HR = 2.02, 95 %CI: 1.54-2.63) in ICI-treated NSCLC patients. The retrospective validation confirmed the above result and identified opioid use as an independent unfavorable predictor for PFS and OS in both the entire cohort and ICI subgroup. The bioinformatic analysis identified 14 prognostic OTGs (CYP17A1, PDYN, PYCARD, FGA, NTSR1, FABP1, HPCA, PENK, PDGFB, LIN7A, FKBP5, TYMS, CACNA1H and LDHA), most of which were correlated with immune infiltration in NSCLC. A risk model was constructed based on 14 OTGs and found to effectively stratify the clinical outcome in both the training and validation set, independent of age, gender and TNM staging system. The model was also significantly correlated with infiltration of activated dendritic cells, neutrophils and tumor infiltrating lymphocytes. Finally, a nomogram was constructed based on the model, age, gender and TNM stage, which could predict well the 1-, 3- and 5-year survival of NSCLC patients.

CONCLUSION

Opioid use is correlated with the poor clinical outcome in ICI-treated NSCLC patients. Precise pain management is highly advocated and opioids are recommended to be cautiously used in these patients. OTGs have the potential to be prognostic biomarkers for NSCLC patients and their role in tumor immunity needs to be further investigated.

Problems with opioids - beyond misuse

The U.S. is grappling with an opioid epidemic, with millions of adults on long-term opioid therapy (LTOT). Although patients often report pain relief and improved daily function with opioids, research shows no significant differences in short-term outcomes between opioid and non-opioid users, as well as no long-term opioid benefits. This scoping review aims to identify lesser-known side effects of long-term opioid use and increase awareness of them, allowing healthcare providers and patients to better assess the risks and benefits of opioid use. Our data search from PubMed and Google Scholar used keywords related to opioids, chronic pain, hypogonadism, endocrinopathies, cancer progression, cardiovascular events, renovascular events, sleep disturbances, mood disorders and others, narrowing down to English-language full articles published from January 2018 to April 2023. This review emphasizes the probable serious adverse consequences of long-term opioid use on various body systems in patients with chronic pain. Given the lack of long-term benefits and significant adverse effects, our review underscores the critical need for healthcare providers to include these risks in discussions with patients when considering the long-term use of opioid therapy.

Anemoside B4 alleviates arthritis pain via suppressing ferroptosis-mediated inflammation

Chronic pain is the key manifestations of rheumatoid arthritis. Neuroinflammation in the spinal cord drives central sensitization and chronic pain. Ferroptosis has potentially important roles in the occurrence of neuroinflammation and chronic pain. In the current study, mouse model of collagen-induced arthritis was established by intradermal injection of type II collagen in complete Freund's adjuvant (CFA) solution. CFA inducement resulted in swollen paw and ankle, mechanical and spontaneous pain, and impaired motor coordination. The spinal inflammation was triggered, astrocytes were activated, and increased NLRP3-mediated inflammatory signal was found in CFA spinal cord. Oxidative stress and ferroptosis in the spinal cord were manifested. Meanwhile, enhancive spinal GSK-3β activity and abnormal phosphorylated Drp1 were observed. To investigate the potential therapeutic options for arthritic pain, mice were intraperitoneally injected with AB4 for three consecutive days. AB4 treatment reduced pain sensitivity and increased the motor coordination. In the spinal cord, AB4 treatment inhibited NLRP3 inflammasome-mediated inflammatory response, increased antioxidation, decreased mitochondrial reactive oxygen species and ferroptosis. Furthermore, AB4 decreased GSK-3β activity by binding with GSK-3β through five electrovalent bonds. Our findings indicated that AB treatment relieves arthritis pain by inhibiting GSK-3β activation, increasing antioxidant capability, reducing Drp1-mediated mitochondrial dysfunction and suppressing neuroinflammation.

Impact of Opioid Use on Duration of Therapy and Overall Survival for Patients with Advanced Non-Small Cell Lung Cancer Treated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICI) have significantly improved outcomes in advanced non-small cell lung cancer (NSCLC). We evaluated the effect of opioid use on outcomes in patients receiving ICI either alone or with chemotherapy. We conducted a retrospective review of 209 patients with advanced NSCLC who received an ICI at the University of Virginia between 1 February 2015 and 1 January 2020. We performed univariate and multivariate analyses to evaluate the impact of opioid use on duration of therapy (DOT) and overall survival (OS). Patients with no or low opioid use (n = 172) had a median DOT of 12.2 months (95% CI: 6.9-17.4) compared to 1.9 months (95% CI: 1.8-2.0) for those with high opioid use (n = 37, HR 0.26 95% CI: 0.17-0.40, p < 0.001). Patients with no or low opioid use had a median OS of 22.6 months (95% CI: 14.8-30.4) compared to 3.8 months (95% CI: 2.7-4.9) for those with high opioid use (HR 0.26 95% CI: 0.17-0.40 p < 0.001). High opioid use was associated with a shorter DOT and worse OS. This difference remained significant when accounting for possible confounding variables. These data warrant investigation of possible mechanistic interactions between opioids, tumor progression, and ICIs, as well as prospective evaluation of opioid-sparing pain management strategies, where possible.

Emodin inhibits HDAC6 mediated NLRP3 signaling and relieves chronic inflammatory pain in mice

Chronic pain reduces the quality of life and ability to function of individuals suffering from it, making it a common public health problem. Neuroinflammation which is mediated by the Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation in the spinal cord participates and modulates chronic pain. A chronic inflammatory pain mouse model was created in the current study by intraplantar injection of complete Freund's adjuvant (CFA) into C57BL/6J left foot of mice. Following CFA injection, the mice had enhanced pain sensitivities, decreased motor function, increased spinal inflammation and activated spinal astrocytes. Emodin (10 mg/kg) was administered intraperitoneally into the mice for 3 days. As a result, there were fewer spontaneous flinches, higher mechanical threshold values and greater latency to fall. Additionally, in the spinal cord, emodin administration reduced leukocyte infiltration level, downregulated protein level of IL-1β, lowered histone deacetylase (HDAC)6 and NLRP3 inflammasome activity and suppressed astrocytic activation. Emodin also binds to HDAC6 via four electrovalent bonds. In summary, emodin treatment blocked the HDAC6/NLRP3 inflammasome signaling, suppresses spinal inflammation and alleviates chronic inflammatory pain.

Potential 'anti-cancer' effects of esketamine on proliferation, apoptosis, migration and invasion in esophageal squamous carcinoma cells

BACKGROUND

Esketamine, an N-methyl-D-aspartate receptor antagonist, is commonly used for anesthesia and analgesia clinically. It was reported to negatively regulate cell proliferation, metastasis and apoptosis in cancer cells, including lung cancer and pancreatic cancer. However, its impact on esophageal squamous cell carcinoma (ESCC) malignance and underlying mechanism remain elusive. This study was aimed to investigate the antitumor effects of esketamine on ESCC in vitro.

METHODS

ESCC cell lines (KYSE-30 and KYSE-150) were cultured and treated with different concentrations (0.1, 0.2, 0.4, 0.8, 1, 2 mM) of esketamine. Their proliferation, apoptosis, migration and invasion were assessed with various assays. Furthermore, mass spectrometry-based proteomic analysis and GO/KEGG enrichment analysis were applied to characterize the differentially expressed proteins (DEPs) with or without esketamine treatment. Some key proteins identified from proteomic analysis were further validated with Western blotting and bioinformatics analysis.

RESULTS

Esketamine significantly inhibited the proliferation, migration, invasion and promoted apoptosis of the both types of cell lines in a dose- and time-dependent manner. A total of 321 common DEPs, including 97 upregulated and 224 downregulated proteins, were found with HPLC-MS analyses. GO/KEGG enrichment analysis suggested that esketamine affected cell population proliferation, GTPase activity and Apelin signaling pathway. The ERCC6L, AHR and KIF2C protein expression was significantly downregulated in these ESCC cells treated with esketamine compared to the controls and their changes were associated with the suppressive effects of esketamine on ESCC through bioinformatics analysis.

CONCLUSIONS

Our work demonstrated that esketamine has potential anti-ESCC properties in vitro but subjected to further in vivo and clinical study.

Effects of Laughter Therapy on Improving Negative Emotions Associated with Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

With aging and growth of the population, the risk of cancer incidence and mortality is rapidly increasing. However, psychosocial treatment has been seriously neglected in many healthcare settings. Laughter therapy is a therapeutic program to improve emotional wellbeing and health which has been applied as a complementary treatment. We aim to explore effects of laughter therapy for patients with cancer on their negative emotions such as depression, anxiety, stress, pain, and fatigue.

METHODS

We searched the Cochrane Library, Embase, PubMed, Scopus, Web of Science, WANFANG data, Weipu (VIP), Chinese National Knowledge Infrastructure (CNKI) and independently rated the risk of bias in every article using the Cochrane Collaboration's Risk of Bias Assessment Tool. Review Manager and STATA software were used to pool the individually included studies.

RESULTS

Seven studies were found eligible to be included in the present review. Overall, study quality was relatively high. Our findings suggest that laughter therapy might have a positive effect on improving emotional response in cancer patients. Arguably, laughter therapy, whether humor or laughter, has a positive effect on anxiety, stress, pain feeling, fatigue, and depression in cancer patients.

CONCLUSIONS

Laughter therapy is a convenient, multi-modality, flexible-duration therapy to improve negative emotions in cancer patients, regardless of their gender, age, and type of cancer.

Morphine decreases cytotoxicity and mutagenicity of doxorubicin in vitro: Implications for cancer chemotherapy

Morphine is the most common opioid analgesic administered to treat pain in patients undergoing cancer chemotherapy. This study aimed to evaluate the cytotoxic and mutagenic effects of morphine alone and in combination with doxorubicin (Dox), an antineoplastic agent largely used in patients with solid cancers. Cytotoxicity was evaluated in neuroblastoma (SH-SY5Y) and fibroblast (V79) cells using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay while mutagenicity was assessed using the Salmonella/microsome assay in the absence and in the presence of S9 mix. Morphine showed a cytotoxic effect mainly on SH-SY5Y cells and reduced the cytotoxic effects of Dox when evaluated in a co-treatment procedure. In the Salmonella/microsome assay, it was observed that morphine did not induce mutations and, in fact, decreased the mutagenic effects induced by Dox in TA98 and TA102 strains in the absence of metabolic activation. Furthermore, in the presence of metabolic activation, no induction of mutations was observed with morphine. In conclusion, morphine decreased Dox cytotoxicity in both neuronal and non-neuronal cells and showed antimutagenic effects in the TA102 strain which detects mutagens inducing DNA oxidative damages. However, morphine decreased frameshift mutations induced by Dox in non-cytotoxic concentrations, an effect suggesting interference of Dox intercalation activity that could decrease its chemotherapeutic efficacy. These compelling findings highlight the importance of conducting further studies to explore the potential implications of co-administering morphine and Dox during cancer chemotherapy.

P2Y12 receptor involved in the development of chronic nociceptive pain as a sensory information mediator

Direct or indirect damage to the nervous system (such as inflammation or tumor invasion) can lead to dysfunction and pain. The generation of pain is mainly reflected in the activation of glial cells and the abnormal discharge of sensory neurons, which transmit stronger sensory information to the center. P2Y12 receptor plays important roles in physiological and pathophysiological processes including inflammation and pain. P2Y12 receptor involved in the occurrence of pain as a sensory information mediator, which enhances the activation of microglia and the synaptic plasticity of primary sensory neurons, and reaches the higher center through the ascending conduction pathway (mainly spinothalamic tract) to produce pain. While the application of P2Y12 receptor antagonists (PBS-0739, AR-C69931MX and MRS2359) have better antagonistic activity and produce analgesic pharmacological properties. Therefore, in this article, we discussed the role of the P2Y12 receptor in different chronic pains and its use as a pharmacological target for pain relief.

Extended Opioid Exposure Modulates the Molecular Metabolism of Clear Cell Renal Cell Carcinoma

Opioids are commonly prescribed for extended periods of time to patients with advanced clear cell renal cell carcinoma to assist with pain management. Because extended opioid exposure has been shown to affect the vasculature and to be immunosuppressive, we investigated how it may affect the metabolism and physiology of clear cell renal cell carcinoma. RNA sequencing of a limited number of archived patients' specimens with extended opioid exposure or non-opioid exposure was performed. Immune infiltration and changes in the microenvironment were evaluated using CIBERSORT. A significant decrease in M1 macrophages and T cells CD4 memory resting immune subsets was observed in opioid-exposed tumors, whereas the changes observed in other immune cells were not statistically significant. Further RNA sequencing data analysis showed that differential expression of KEGG signaling pathways was significant between non-opioid-exposed specimens and opioid-exposed specimens, with a shift from a gene signature consistent with aerobic glycolysis to a gene signature consistent with the TCA cycle, nicotinate metabolism, and the cAMP signaling pathway. Together, these data suggest that extended opioid exposure changes the cellular metabolism and immune homeostasis of ccRCC, which might impact the response to therapy of these patients, especially if the therapy is targeting the microenvironment or metabolism of ccRCC tumors.

Photodynamic therapy in oral cancer: a review of clinical studies

A significant mortality rate is associated with oral cancer, particularly in cases of late-stage diagnosis. Since the last decades, oral cancer survival rates have only gradually improved despite advances in treatment. This poor success rate is mainly due to the development of secondary tumors, local recurrence, and regional failure. Invasive treatments frequently have a negative impact on the aesthetic and functional outcomes of survivors. Novel approaches are thus needed to manage this deadly disease in light of these statistics. In photodynamic therapy (PDT), a light-sensitive medication called a photosensitizer is given first, followed by exposure to light of the proper wavelength that matches the absorbance band of the photosensitizer. The tissue oxygen-induced cytotoxic free radicals kill tumor cells directly, harm the microvascular structure, and cause inflammatory reactions at the targeted sites. In the case of early lesions, PDT can be used as a stand-alone therapy, and in the case of advanced lesions, it can be used as adjuvant therapy. The current review article discussed the uses of PDT in oral cancer therapy based on recent advances in this field.

Immune Checkpoint Inhibitors and Opioids in Patients with Solid Tumours: Is Their Association Safe? A Systematic Literature Review

BACKGROUND

Immune checkpoint inhibitors (ICIs) represent one of the most effective treatments for patients with cancer. As their activity relies on host immune system reactivity, the role of concomitant medications such as corticosteroids and antibiotics has been extensively evaluated. Preclinical data suggest that opioids may influence the immune system.

METHODS

a systematic literature revision was performed using specific keywords on the major search engines. Two authors analysed all the studies and provided a selection of the following inclusion and exclusion criteria, respectively: 1. data collection of patients older than 18 years old affected by solid tumours; 2. description of ICIs efficacy in terms of PFS, OS, TTF, and ORR; 3. concomitant ICIs-opioids treatment and 1. language different from English; 2. not pertinent analyses.

RESULTS

523 studies were analysed, and 13 were selected and included in our series. A possible negative interaction between oral opioids and ICIs efficacy was observed. Most evidence was retrospective, and studies were heterogeneous.

CONCLUSIONS

Even if oral opioids seem to impact negatively on ICIs efficacy in cancer patients, to date there is not sufficient evidence to avoid their prescription in this population.

Effect of Opioids on Survival in Patients with Cancer

Opioids are commonly used for pain management in patients with cancer. They have a range of unwanted effects, including some that potentially influence cancer growth. This article reviews the data assessing the effects of opioids on survival in patients with cancer. Many studies assessing this show an association between opioids and decreased survival. This effect is present even at very low doses of opioids. These studies do not assess causality, so it is not known if it is a direct effect of opioids on survival. As the control groups are not matched to the opioid group it might be that opioids are being used to control pain and patients receiving opioids have more aggressive cancers and it is the underlying cancer which is causing the decreased survival. Furthermore, although some studies allude to different opioids having different effects on survival, often all opioids are pooled in analysis. Future work needs to try to ascertain causality and differentiate between different opioids, pain, and cancer-mediated effects on survival in specific cancer types. Until then, opioids should continue to be used in patients with cancer as part of measures to optimise comfort and quality of life.

Catalpol ameliorates CFA-induced inflammatory pain by targeting spinal cord and peripheral inflammation

Chronic, inflammatory pain is an international health concern that severely diminishes individuals' quality of life. Catalpol is an iridoid glycoside derived from the roots of Rehmannia glutinosa that possesses anti-inflammatory, antioxidant, and neuroprotective properties for the treating multiple kinds of disorders. Nevertheless, catalpol's impacts on inflammatory pain and its potential methods of action are still unclear. The purpose of this investigation is to determine the mechanism of catalpol to reduce the inflammatory pain behaviors in a rat model with complete Freund's adjuvant (CFA). Catwalk, Von-Frey, and open field testing were performed for behavioral assessment. Western blot analysis and real-time quantitative PCR (RT-PCR) were employed to identify variations in molecular expression, while immunofluorescence was utilized to identify cellular localization. Catalpol effectively reduced CFA-induced mechanical allodynia and thermal hyperalgesia when injected intrathecally. Moreover, catalpol can regulate the HDAC4/PPAR-γ-signaling pathway in CFA rat spinal cord neurons. Meanwhile catalpol significantly decreased the expression of the NF-κB/NLRP3 inflammatory axis in the spinal cord of CFA rats. In addition, both in vivo and in vitro research revealed that catalpol treatment inhibited astrocyte activation and increase inflammatory factor expression. Interestingly, we also found that catalpol could alleviate peripheral pain by inhibiting tissue inflammation. Taken together, the findings declared that catalpol may inhibit inflammatory pain in CFA rats by targeting spinal cord and peripheral inflammation.

Applications of nanomaterials for gastrointestinal tumors: A review

Nanotechnology is the emerging and advance field of research for the diagnosis and treatment of various diseases. With the development of nanotechnology, different nanoparticles are used in the treatment of cancer due to their unique optical properties, excellent biocompatibility, surface effects, and small size effects. Nanoparticles are the particles which have the particular size from 1 to 100 nm. These nanoparticles are zero dimension, one dimension, two dimension and three dimension etc. In present scenario a variety of research is focused on the tailored synthesis of nanoparticles for medicinal applications that can be used for cancer treatment based on the morphology, composition, interaction with target cell. The gastrointestinal (GI) tumors are found one of the deadest cancer types with highest reoccurrence rates. The diagnosis and treatment of gastrointestinal cancer is very challenging due to its deep location and complicated surgery. Nanotechnology provides fast diagnosis and immediate treatment for the gastrointestinal disease. A variety of nanomaterials are used for the diagnosis and treatment of GI disease. Nanoparticles target directly to the tumor cell as diagnostic and therapeutic tools facilitating the identification and removal of tumor cells. A number of nanoparticles are developed for the uses are quantum dots (QDs), carbon nanotubes (CNTs), metallic nanoparticles (MNPs), Dendrimers etc. This review article gives an overview of the most promising nanomaterials used for the diagnosis and treatment of GI diseases. This review attempts to incorporate numerous uses for the most current nanomaterials, which have great potential for treating gastrointestinal diseases.