Duloxetine improves cancer-associated pain in a mouse model of pancreatic cancer through stimulation of noradrenaline pathway and its antitumor effects

Pancreatic stellate cell: Update on molecular investigations and clinical translation in pancreatic cancer

Pancreatic cancer is a particularly aggressive tumor, distinguished by the presence of a prominent collagenous stroma and desmoplasia that envelops the tumor cells. Pancreatic stellate cell (PSC) contributes to the formation of a dense fibrotic stroma and has been demonstrated to facilitate tumor progression. As the significance of PSCs is increasingly revealed, more explorations are focused on the complex molecular mechanisms and tumor-stromal crosstalk in order to guide potential therapeutic approaches through deactivating or reprogramming PSCs. Nevertheless, significant challenges persist in translating preclinical discoveries into clinical applications. In this review, we expect to offer a comprehensive overview of the latest molecular advancements in PSCs, along with new insights into the clinical therapeutic strategies targeting PSCs.

Duloxetine improves hyperosmia in mice with pancreatic cancer by increasing dopamine levels in the olfactory bulb

The mechanism and therapeutic insights regarding hyperosmia to food odors in patients with cancer are poorly understood. We therefore evaluated the mechanism and effect of duloxetine in KPPC (LSL-KrasG12D/+; Trp53flox/flox; Pdx-1cre/+) mice with pancreatic cancer. Six-week-old KPPC mice were orally administered 4 mg/kg/day duloxetine (n = 7) or vehicle water (n = 6) daily until the humane endpoint. In healthy mice (n = 6), the buried pellet test (BPT) time was stable during the observation period, whereas BPT time was shortened in vehicle-treated KPPC mice, and this effect was inhibited by administration of duloxetine. The number of degenerated glomerular/mitral cells in the ventral olfactory bulb increased in vehicle-treated KPPC mice compared with healthy mice, and this effect was inhibited by duloxetine. Electron microscopic analysis revealed enlarged mitochondria in the degenerated neural cells. High-performance liquid chromatography analysis revealed a decrease in dopamine levels in the olfactory bulb of KPPC mice compared with healthy mice. The shortened BPT time in vehicle-treated KPPC mice was extended by L-dopa injection and wheel activity (n = 6 each). These findings suggest that duloxetine improves hyperosmia to food odors in mice with pancreatic cancer by increasing dopamine levels in the olfactory bulb.

Proapoptotic role of CDK1 in overcoming paclitaxel resistance in ovarian cancer cells in response to combined treatment with paclitaxel and duloxetine

BACKGROUND

Paclitaxel resistance and recurrence are major obstacles in ovarian cancer, which is the leading cause of death among gynecologic cancers. During cancer cell progression, cyclin-dependent kinase 1 (CDK1) drives cells through the G2 phase and into mitosis. In this study, we demonstrated that CDK1 played a crucial role in switching paclitaxel-resistant ovarian cancer cells from mitotic arrest to apoptosis following combined treatment with paclitaxel and duloxetine, an antidepressant known as a serotonin-norepinephrine reuptake inhibitor (SNRI).

METHODS

Cell viability was assessed by MTT assay. Apoptotic cell death and mitochondrial membrane potential (MMP) were detected by flow cytometry. Protein expression levels were explored using western blotting. Mitochondrial and cytosolic fractionation were performed to determine the mitochondrial localization of proteins. Immunofluorescence was used to detect protein expression levels and localization.

RESULTS

Combined treatment with paclitaxel and duloxetine induced apoptotic cell death in paclitaxel-resistant ovarian cancer cells. We suggested that combined treatment of these drugs induced CDK1 activation and increased mitochondrial localization of activated CDK1, which caused phosphorylation of the antiapoptotic Bcl-2 and Bcl-xL proteins. Selective CDK1 inhibitors blocked Bcl-2 and Bcl-xL phosphorylation induced by paclitaxel and duloxetine, and strongly suppressed apoptotic cell death. Furthermore, we demonstrated that S6K is a potential upstream mediator of the proapoptotic activation of CDK1.

CONCLUSION

Taken together, switching CDK1 to a proapoptotic role through the combination of paclitaxel and duloxetine could overcome paclitaxel resistance in ovarian cancer cells, providing promising therapeutic strategies for treating paclitaxel-resistant ovarian cancer.

The role of DPYD and the effects of DPYD suppressor luteolin combined with 5-FU in pancreatic cancer

BACKGROUND

Despite advances in the treatment of cancer, pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to the lack of effective therapies. Our previous study showed that Luteolin (Lut), a flavonoid, suppressed pancreatocarcinogenesis and reduced the expression of dihydropyrimidine dehydrogenase (DPYD), an enzyme that degrades pyrimidines such as 5-fluorouracil (5-FU), in PDACs. In this study, we investigated the role of DPYD and evaluated the therapeutic potential of combining 5-FU with Lut in PDACs.

METHODS AND RESULTS

PDAC cells overexpressing DPYD showed increased proliferation, and invasiveness, adding to the resistance to 5-FU. The xenograft tumors of DPYD-overexpressing PDAC cells also exhibit enhanced growth and invasion compared to the control xenograft tumors. RNA-seq analysis of the DPYD-overexpressing PDAC xenograft tumors revealed an upregulation of genes associated with metallopeptidase activity-MMP9 and MEP1A. Furthermore, the overexpression of MEP1A in PDAC was associated with invasion. Next, we investigated the combined effects of Lut, a DPYD suppressor, and 5-FU on DPYD-overexpressing xenograft tumors and PDAC of Pdx1-Cre; LSL-KrasG12D/+; Trp53flox/flox(KPPC) mice. Neither single administration of 5-FU nor Lut showed significant inhibitory effects; however, the combined administration of 5-FU and Lut exhibited a significant tumor-suppressive effect in both the xenograft tumors and KPPC models.

CONCLUSION

We have elucidated that DPYD expression contributes to proliferation, invasiveness, and 5-FU resistance, in PDACs. The combination therapy of Lut and 5-FU holds the potential for enhanced efficacy against PDACs.

Effects of tramadol via a µ-opioid receptor on pancreatic ductal adenocarcinoma in vitro and in vivo

INTRODUCTION

Tramadol, a weak opioid anesthetic, is used for pain management in patients with cancer, but the effects of tramadol on cancer via µ-opioid receptor are still unknown. We assessed the effects of tramadol on pancreatic ductal adenocarcinoma using transgenic mice (LSL-KrasG12D/+; Trp53flox/flox; Pdx-1cre/+ ).

METHODS

Six-week-old transgenic mice were orally administered 10 mg/kg/day tramadol (n=12), 10 mg/kg/day tramadol and 1 mg/kg/day naltrexone (n=9), or vehicle water (n=14) until the humane endpoint. Cancer-related pain and plasma cytokine levels were assessed by the mouse grimace scale and cytokine array, respectively. Tumor status was determined histopathologically. Tramadol's effects on proliferation and invasion in pancreatic ductal adenocarcinoma cell lines were studied in vitro.

RESULTS

Tramadol with/without naltrexone improved mouse grimace scale scores while decreasing inflammatory cytokines such as tumor necrosis factor-α and interleukin-6. Proliferative Ki-67 and cyclins decreased by tramadol, while local M1-like tumor-associated macrophages increased by tramadol, which was blocked by naltrexone. Meanwhile, tramadol with/without naltrexone reduced juxta-tumoral cancer-associated fibroblasts and M2-like tumor-associated macrophages. Tumor-associated neutrophils, natural killers, and cytotoxic T cells were not altered. Tramadol decreased the proliferative and invasive potentials of pancreatic ductal adenocarcinoma cell lines via decreasing cyclins/cyclin-dependent kinases, which was partially reversed by naltrexone.

CONCLUSIONS

These findings imply that tramadol might be a useful anesthetic for pancreatic ductal adenocarcinoma: inhibiting the proliferation and invasion along with increasing antitumor M1-like tumor-associated macrophages via the µ-opioid receptor, while improving cancer-associated pain possibly through the antitumor effects with the decrease of inflammatory cytokines.

Comparative Efficacy and Safety of Antidepressants for Patients with Chronic Back Pain: A Network Meta-Analysis

Various antidepressants have introduced in clinical practice for pain management, but it is important to understand how to properly use them. We therefore performed a systematic review and network meta-analysis to compare and rank the efficacy and safety of antidepressants for patients with chronic back pain. We identified eligible randomized controlled trials (RCTs) that investigated the efficacy and safety of antidepressants for chronic back pain from PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov, searching from inception to May 2023. Six categories of antidepressants for the treatment of chronic back pain were included, and the surface under the cumulative ranking probabilities was applied to rank the treatment strategies. Overall, we selected 19 RCTs recruiting 2903 patients for the meta-analysis. Tricyclic antidepressants presented the best relative effects for relief in pain score (surface under the cumulative ranking, 84.4%). The results of pairwise comparison analyses found the use of serotonin-noradrenaline reuptake inhibitors (SNRIs) significantly reduced pain score and low disability score compared with placebo, irrespective of treatment duration. Noradrenaline-dopamine reuptake inhibitors (relative risk [RR], 2.80; 95% confidence interval [CI], 1.30-6.03; P = .008) and SNRIs (RR, 1.17; 95% CI, 1.07-1.27; P < .001) significantly increased the risk of adverse events. SNRIs were associated with an increased risk of withdrawal due to adverse events (RR, 2.37; 95% CI, 1.64-3.43; P < .001). This study found that antidepressants are more efficacious than placebos for treating chronic back pain, and tricyclic antidepressants are the most likely medications that lead to pain relief.

Recent advances in drug delivery and targeting for the treatment of pancreatic cancer

Despite significant treatment efforts, pancreatic ductal adenocarcinoma (PDAC), the deadliest solid tumor, is still incurable in the preclinical stages due to multifacet stroma, dense desmoplasia, and immune regression. Additionally, tumor heterogeneity and metabolic changes are linked to low grade clinical translational outcomes, which has prompted the investigation of the mechanisms underlying chemoresistance and the creation of effective treatment approaches by selectively targeting genetic pathways. Since targeting upstream molecules in first-line oncogenic signaling pathways typically has little clinical impact, downstream signaling pathways have instead been targeted in both preclinical and clinical studies. In this review, we discuss how the complexity of various tumor microenvironment (TME) components and the oncogenic signaling pathways that they are connected to actively contribute to the development and spread of PDAC, as well as the ways that recent therapeutic approaches have been targeted to restore it. We also illustrate how many endogenous stimuli-responsive linker-based nanocarriers have recently been developed for the specific targeting of distinct oncogenes and their downstream signaling cascades as well as their ongoing clinical trials. We also discuss the present challenges, prospects, and difficulties in the development of first-line oncogene-targeting medicines for the treatment of pancreatic cancer patients.

Automated phenotyping of postoperative delirium-like behaviour in mice reveals the therapeutic efficacy of dexmedetomidine

Postoperative delirium (POD) is a complicated and harmful clinical syndrome. Traditional behaviour analysis mostly focuses on static parameters. However, animal behaviour is a bottom-up and hierarchical organizational structure composed of time-varying posture dynamics. Spontaneous and task-driven behaviours are used to conduct comprehensive profiling of behavioural data of various aspects of model animals. A machine-learning based method is used to assess the effect of dexmedetomidine. Fourteen statistically different spontaneous behaviours are used to distinguish the non-POD group from the POD group. In the task-driven behaviour, the non-POD group has greater deep versus shallow investigation preference, with no significant preference in the POD group. Hyperactive and hypoactive subtypes can be distinguished through pose evaluation. Dexmedetomidine at a dose of 25 μg kg-1 reduces the severity and incidence of POD. Here we propose a multi-scaled clustering analysis framework that includes pose, behaviour and action sequence evaluation. This may represent the hierarchical dynamics of delirium-like behaviours.

Mirogabalin improves cancer-associated pain but increases the risk of malignancy in mice with pancreatic cancer

ABSTRACT

Mirogabalin, a selective voltage-gated calcium channel α2δ ligand, improves peripheral neuropathic pain; however, its effects on patients with cancers including pancreatic ductal adenocarcinoma (PDAC) remain unknown. We analyzed the effects of mirogabalin on a KPPC ( LSL-KrasG12D/+; Trp53flox/flox; Pdx-1cre/+ ) mouse model of PDAC. Six-week-old KPPC mice received oral mirogabalin (10 mg/kg/day) (n = 10) or vehicle water (n = 14) until the humane end point. Cancer-associated pain was evaluated using the scores of hunching and mouse grimace scale (MGS). Tumor status and plasma cytokine levels were determined using histopathological analysis and cytokine array, respectively. The effects of mirogabalin on the proliferative ability of PDAC cell lines were determined. The scores of the hunching and MGS improved after mirogabalin administration with a decrease in the plasma levels of inflammatory cytokines, such as tumor necrosis factor-α, interleukin-6, and interferon-γ. Although no significant difference in the survival rate was observed, mirogabalin significantly increased pancreatic tumor size and proliferative index of Ki-67 and cyclins. Local arginase-1 + M2-like tumor-associated macrophages and CD31 + tumor blood vessels increased after mirogabalin administration. By contrast, the number of α-smooth muscle actin + cancer-associated fibroblasts, desmoplastic stroma, and CD8 + T cells decreased. Local myeloperoxidase + tumor-associated neutrophils and CD45R + B cells were unaltered. Mirogabalin enhanced the proliferative ability of PDAC cell lines with the upregulation of cyclins and cyclin-dependent kinases; however, it inhibited the potential of pancreatic stellate cells in vitro. Therefore, our results suggest that mirogabalin improves cancer-associated pain but enhances the proliferative potential of PDAC in vitro and in vivo.

Calcitonin Related Polypeptide Alpha Mediates Oral Cancer Pain

Oral cancer patients suffer pain at the site of the cancer. Calcitonin gene related polypeptide (CGRP), a neuropeptide expressed by a subset of primary afferent neurons, promotes oral cancer growth. CGRP also mediates trigeminal pain (migraine) and neurogenic inflammation. The contribution of CGRP to oral cancer pain is investigated in the present study. The findings demonstrate that CGRP-immunoreactive (-ir) neurons and neurites innervate orthotopic oral cancer xenograft tumors in mice. Cancer increases anterograde transport of CGRP in axons innervating the tumor, supporting neurogenic secretion as the source of CGRP in the oral cancer microenvironment. CGRP antagonism reverses oral cancer nociception in preclinical oral cancer pain models. Single-cell RNA-sequencing is used to identify cell types in the cancer microenvironment expressing the CGRP receptor components, receptor activity modifying protein 1 Ramp1 and calcitonin receptor like receptor (CLR, encoded by Calcrl). Ramp1 and Calcrl transcripts are detected in cells expressing marker genes for Schwann cells, endothelial cells, fibroblasts and immune cells. Ramp1 and Calcrl transcripts are more frequently detected in cells expressing fibroblast and immune cell markers. This work identifies CGRP as mediator of oral cancer pain and suggests the antagonism of CGRP to alleviate oral cancer pain.

The application of antidepressant drugs in cancer treatment

Antidepressants refer to psychotropic drugs which are used to treat mental illness with prominent emotional depression symptoms. It was reported that antidepressants had associated with anti-carcinogenic function which was associated with various signaling pathways and changing of microenvironment. Its mechanism includes cell apoptosis, antiproliferative effects, mitochondria-mediated oxidative stress, DNA damaging, changing of immune response and inflammatory conditions, and acting by inhibiting multidrug resistance of cancer cells. Accumulated studies showed that antidepressants influenced the metabolic pathway of tumor cells. This review summarized recent developments with the impacts and mechanisms of 10 kinds of antidepressants in carcinostasis. Antidepressants are also used in combination therapy with typical anti-tumor drugs which shows a synergic effect in anti-tumor. By contrast, the promotion roles of antidepressants in increasing cancer recurrence risk, mortality, and morbidity are also included. Further clinical experiments and mechanism analyses needed to be achieved. A full understanding of the underlying mechanisms of antidepressants-mediated anticarcinogenic effects may provide new clues for cancer prevention and clinical treatment.

Hydrogel Loaded with VEGF/TFEB-Engineered Extracellular Vesicles for Rescuing Critical Limb Ischemia by a Dual-Pathway Activation Strategy

Critical limb ischemia (CLI) is the most severe clinical manifestation of peripheral arterial disease, which causes many amputations and deaths. Conventional treatment strategies for CLI (e.g., stent implantation and vascular surgery) bring surgical risk, which are not suitable for each patient. Extracellular vesicles (EVs) can be a potential solution for CLI. Herein, vascular endothelial growth factor (VEGF; i.e., a crucial molecule related to angiogenesis) and transcription factor EB (TFEB; i.e., a pivotal regulator of autophagy) are chosen as the target gene to improve the bioactivity of EVs derived from endothelial cells. The VEGF/TFEB-engineered EVs (Engineered-EVs) are fabricated by genetically engineering the parent cells, and their versatile functions are confirmed using three cell models (human umbilical vein endothelial cells, myoblast, and monocytes). Injectable thermal-responsive hydrogel are then combined with Engineered-EVs to combat CLI. These results reveal that the hydrogel can enhance the stability of Engineered-EVs in vivo and release EVs at different temperatures. Moreover, the results of animal studies indicate that Engineered-EV/Hydrogel can significantly improve neovascularization, attenuate muscle injury, and recover limb function after CLI. Finally, mechanistic studies shed light on the therapeutic effect of Engineered-EV/Hydrogel due to the activated VEGF/VEGFR pathway and autophagy-lysosomal pathway.

Midazolam exhibits antitumour and anti-inflammatory effects in a mouse model of pancreatic ductal adenocarcinoma

BACKGROUND

Anaesthesia and perioperative management contribute to long-term outcomes of patients with cancer, including pancreatic ductal adenocarcinoma. We assessed the antitumour, anti-inflammatory, and analgesic effects of midazolam on LSL-Kras^G12D/+;Trp53^flox/flox;Pdx-1^cre/+ transgenic mice with pancreatic ductal adenocarcinoma.

METHODS

Six-week-old transgenic mice were administered midazolam 30 mg kg^-1 day^-1 p.o. (n=13); midazolam 30 mg kg^-1 day^-1 with 1-(2-chlorophenyl)-N-methyl-N(1-methylpropyl)-3-isoquinoline carboxamide (PK11195) 3 mg kg^-1 day^-1 i.p., a peripheral benzodiazepine receptor antagonist (n=10); or vehicle (water; n=14) until the humane endpoint. Cancer-associated pain was evaluated using hunching score and mouse grimace scale. Tumour stage and immuno-inflammatory status were determined histopathologically. Anti-proliferative and apoptotic potentials of midazolam were investigated using mouse pancreatic ductal adenocarcinoma cell lines.

RESULTS

Midazolam significantly inhibited tumour size and proliferative index of Ki-67 and cyclins in pancreatic ductal adenocarcinoma, which was blocked by administration of PK11195. Local myeloperoxidase⁺ tumour-associated neutrophils, arginase-1⁺ M2-like tumour-associated macrophages, and CD11b⁺Ly-6G⁺ polymorphonuclear myeloid-derived suppressor cells were reduced by midazolam, which was antagonised by administration of PK11195. Hunching and mouse grimace scale were improved by midazolam, whereas the scores increased with midazolam+PK11195 treatment. Plasma pro-inflammatory cytokines, such as interleukin-6 and CC chemokine ligand (CCL)2, CCL3, and CCL5, were reduced by midazolam, whereas these cytokines increased with PK11195. Midazolam inhibited pancreatic ductal adenocarcinoma proliferation through downregulation of cyclins and cyclin-dependent kinases and induced apoptosis in vitro.

CONCLUSIONS

These results suggest that midazolam inhibits pancreatic ductal adenocarcinoma proliferation and local infiltration of tumour-associated neutrophils, tumour-associated macrophages, and polymorphonuclear myeloid-derived suppressor cells, thereby inhibiting pancreatic ductal adenocarcinoma progression.

Repositioning of duloxetine to target pancreatic stellate cells

Pancreatic cancer cells (PCCs) are surrounded by an abundant stroma, which is produced by pancreatic stellate cells (PSCs). PSCs promote tumor cell proliferation and invasion. The objective of the current study was to identify compounds that suppress PSC activation. Gene expression profiles of cancer-derived fibroblasts and normal fibroblasts were used, and the pathway analysis suggested altered pathways that were chosen for validation. It was found that the ‘neuroactive ligand-receptor interaction’ pathway from the Kyoto Encyclopedia of Genes and Genomes pathway analysis was one of the altered pathways. Several compounds related with this pathway were chosen, and changes in PSC activity were investigated using fluorescence staining of lipid droplets, reverse transcription-quantitative PCR, western blotting, and invasion and migration assays. Among these candidates, duloxetine, a serotonin-noradrenaline reuptake inhibitor, was found to suppress PSC activation and disrupt tumor-stromal interaction. Thus, duloxetine may be a potential drug for suppressing PSC activation and pancreatic cancer growth.

Neuropathic Pain in Pancreatic Cancer: An Update of the Last Five Years

Pain is the main symptom of pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC). Pain in pancreatic cancer may be visceral, somatic or neuropathic in origin. Pain is produced by tissue damage, inflammation, ductal obstruction and infiltration. Visceral nociceptive signals caused by damage to the upper abdominal viscera are carried along sympathetic fibers, which travel to the celiac plexus nerves and ganglia, which are found at the T12-L2 vertebral levels, anterolateral to the aorta near the celiac trunk. From here, the signals are transmitted through the splanchnic nerves to the T5-T12 dorsal root ganglia and then on to the higher centers of the central nervous system. Somatic and neuropathic pain may arise from tumor extension into the surrounding peritoneum, retroperitoneum and bones and, in the latter case, into the nerves, such as the lumbosacral plexus. It should also be noted that other types of pain might arise because of therapeutic interventions, such as post-chemoradiation syndromes, which cause mucositis and enteritis. Management with non-steroidal anti-inflammatory agents and narcotics was the mainstay of therapy. In recent years, celiac plexus blocks and neurolysis, as well as intrathecal therapies have been used to control severe pain, at times resulting in a decreased need for drugs, avoiding their unwanted side effects. Pain may impair the patient’s quality of life, negatively affecting patient outcome and resulting in increased psychological stress. Even after recognizing the negative effect of cancer pain on patient overall health, studies have shown that cancer pain is still undertreated. This review focuses on neuropathic pain, which is difficult to handle; thus, the most recent literature was reviewed in order to diagnose neuropathic pain and its management.

Animal Models of Cancer-Related Pain: Current Perspectives in Translation

The incidence of pain in cancer patients during diagnosis and treatment is exceedingly high. Although advances in cancer detection and therapy have improved patient prognosis, cancer and its treatment-associated pain have gained clinical prominence. The biological mechanisms involved in cancer-related pain are multifactorial; different processes for pain may be responsible depending on the type and anatomic location of cancer. Animal models of cancer-related pain have provided mechanistic insights into the development and process of pain under a dynamic molecular environment. However, while cancer-evoked nociceptive responses in animals reflect some of the patients’ symptoms, the current models have failed to address the complexity of interactions within the natural disease state. Although there has been a recent convergence of the investigation of carcinogenesis and pain neurobiology, identification of new targets for novel therapies to treat cancer-related pain requires standardization of methodologies within the cancer pain field as well as across disciplines. Limited success of translation from preclinical studies to the clinic may be due to our poor understanding of the crosstalk between cancer cells and their microenvironment (e.g., sensory neurons, infiltrating immune cells, stromal cells etc.). This relatively new line of inquiry also highlights the broader limitations in translatability and interpretation of basic cancer pain research. The goal of this review is to summarize recent findings in cancer pain based on preclinical animal models, discuss the translational benefit of these discoveries, and propose considerations for future translational models of cancer pain.