Cholecystokinin Receptor Antagonist Research Articles

CCK Receptor Inhibition Reduces Pancreatic Tumor Fibrosis and Promotes Nanoparticle Delivery.

The poor prognosis for pancreatic ductal adenocarcinoma (PDAC) patients is due in part to the highly fibrotic nature of the tumors that impedes delivery of therapeutics, including nanoparticles (NPs). Our prior studies demonstrated that proglumide, a cholecystokinin receptor (CCKR) antagonist, reduced fibrosis pervading PanIN lesions in mice. Here, we further detail how the reduced fibrosis elicited by proglumide achieves the normalization of the desmoplastic tumor microenvironment (TME) and improves nanoparticle uptake. One week following the orthotopic injection of PDAC cells, mice were randomized to normal or proglumide-treated water for 3-6 weeks. Tumors were analyzed ex vivo for fibrosis, vascularity, stellate cell activation, vascular patency, and nanoparticle distribution. The histological staining and three-dimensional imaging of tumors each indicated a reduction in stromal collagen in proglumide-treated mice. Proglumide treatment increased tumor vascularity and decreased the activation of cancer-associated fibroblasts (CAFs). Additionally, PANC-1 cells with the shRNA-mediated knockdown of the CCK2 receptor showed an even greater reduction in collagen, indicating the CCK2 receptors on tumor cells contribute to the desmoplastic TME. Proglumide-mediated reduction in fibrosis also led to functional changes in the TME as evidenced by the enhanced intra-tumoral distribution of small (<12 nm) Rhodamine-loaded nanoparticles. The documented in vivo, tumor cell-intrinsic anti-fibrotic effects of CCK2R blockade in both an immunocompetent syngeneic murine PDAC model as well as a human PDAC xenograft model demonstrates that CCK2R antagonists, such as proglumide, can improve the delivery of nano-encapsulated therapeutics or imaging agents to pancreatic tumors.

The Role of a Cholecystokinin Receptor Antagonist in the Management of Chronic Pancreatitis: A Phase 1 Trial.

Chronic pancreatitis (CP) is a rare but debilitating condition with an 8-fold increased risk of developing pancreatic cancer. In addition to the symptoms that come from the loss of endocrine and exocrine function in CP, the management of chronic pain is problematic. We previously showed that the CCK-receptor antagonist called proglumide could decrease inflammation, acinar-ductal metaplasia, and fibrosis in murine models of CP. We hypothesized that proglumide would be safe and diminish pain caused by CP. A Phase 1 open-labeled safety study was performed in subjects with clinical and radiographic evidence of CP with moderate to severe pain. After a 4-week observation period, the subjects were treated with proglumide in 400 mg capsules three times daily (1200 mg per day) by mouth for 12 weeks, and then subjects returned for a safety visit 4 weeks after the discontinuation of the study medication. The results of three pain surveys (Numeric Rating Scale, COMPAT-SF, and NIH PROMIS) showed that the patients had significantly less pain after 12 weeks of proglumide compared to the pre-treatment observation phase. Of the eight subjects in this study, two experienced nausea and diarrhea with proglumide. These side effects resolved in one subject with doses reduced to 800 mg per day. No abnormalities were noted in the blood chemistries. A blood microRNA blood biomarker panel that corresponded to pancreatic inflammation and fibrosis showed significant improvement. We conclude that proglumide is safe and well tolerated in most subjects with CP at a dose of 1200 mg per day. Furthermore, proglumide therapy may have a beneficial effect by decreasing pain associated with CP.

Cholecystokinin receptor antagonist induces pancreatic stellate cell plasticity rendering the tumor microenvironment less oncogenic

Cholecystokinin receptor antagonist induces pancreatic stellate cell plasticity rendering the tumor microenvironment less oncogenic

Cholecystokinin receptor antagonist challenge elicits brain-wide functional connectome modulation with micronetwork hippocampal decreased calcium transients.

The cortical distribution and functional role of cholecystokinin (CCK) are largely unknown. Here, a CCK receptor antagonist challenge paradigm was developed to assess functional connectivity and neuronal responses. Structural-functional magnetic resonance imaging and calcium imaging were undertaken in environmental enrichment (EE) and standard environment (SE) groups (naïve adult male mice, n = 59, C57BL/B6J, P = 60). Functional connectivity network-based statistics and pseudo-demarcation Voronoi tessellations to cluster calcium signals were used to derive region of interest metrics based on calcium transients, firing rate, and location. The CCK challenge elicited robust changes to structural-functional networks, decreased neuronal calcium transients, and max firing rate (5s) of dorsal hippocampus in SE mice. However, the functional changes were not observed in EE mice, while the decreased neuronal calcium transients and max firing rate (5s) were similar to SE mice. Decreased gray matter alterations were observed in multiple brain regions in the SE group due to CCK challenge, while no effect was observed in the EE group. The networks most affected by CCK challenge in SE included within isocortex, isocortex to olfactory, isocortex to striatum, olfactory to midbrain, and olfactory to thalamus. The EE group did not experience network changes in functional connectivity due to CCK challenge. Interestingly, calcium imaging revealed a significant decrease in transients and max firing rate (5s) in the dorsal CA1 hippocampus subregion after CCK challenge in EE. Overall, CCK receptor antagonists affected brain-wide structural-functional connectivity within the isocortex, in addition to eliciting decreased neuronal calcium transients and max firing rate (5s) in CA1 of the hippocampus. Future studies should investigate the CCK functional networks and how these processes affect isocortex modulation. Significance Statement Cholecystokinin is a neuropeptide predominately found in the gastrointestinal system. Albeit abundantly expressed in neurons, the role and distribution of cholecystokinin are largely unknown. Here, we demonstrate cholecystokinin affects brain-wide structural-functional networks within the isocortex. In the hippocampus, the cholecystokinin receptor antagonist challenge decreases neuronal calcium transients and max firing rate (5s) in CA1. We further demonstrate that mice in environmental enrichment do not experience functional network changes to the CCK receptor antagonist challenge. Environmental enrichment may afford protection to the alterations observed in control mice due to CCK. Our results suggest that cholecystokinin is distributed throughout the brain, interacts in the isocortex, and demonstrates an unexpected functional network stability for enriched mice.

Treatment with a Cholecystokinin Receptor Antagonist, Proglumide, Improves Efficacy of Immune Checkpoint Antibodies in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated deaths worldwide. Treatment with immune checkpoint antibodies has shown promise in advanced HCC, but the response is only 15-20%. We discovered a potential target for the treatment of HCC, the cholecystokinin-B receptor (CCK-BR). This receptor is overexpressed in murine and human HCC and not in normal liver tissue. Mice bearing syngeneic RIL-175 HCC tumors were treated with phosphate buffer saline (PBS; control), proglumide (a CCK-receptor antagonist), an antibody to programmed cell death protein 1 (PD-1Ab), or the combination of proglumide and the PD-1Ab. In vitro, RNA was extracted from untreated or proglumide-treated murine Dt81Hepa1-6 HCC cells and analyzed for expression of fibrosis-associated genes. RNA was also extracted from human HepG2 HCC cells or HepG2 cells treated with proglumide and subjected to RNA sequencing. Results showed that proglumide decreased fibrosis in the tumor microenvironment and increased the number of intratumoral CD8+ T cells in RIL-175 tumors. When proglumide was given in combination with the PD-1Ab, there was a further significant increase in intratumoral CD8+ T cells, improved survival, and alterations in genes regulating tumoral fibrosis and epithelial-to-mesenchymal transition. RNAseq results from human HepG2 HCC cells treated with proglumide showed significant changes in differentially expressed genes involved in tumorigenesis, fibrosis, and the tumor microenvironment. The use of the CCK receptor antagonist may improve efficacy of immune checkpoint antibodies and survival in those with advanced HCC.

Treatment with a cholecystokinin receptor antagonist, proglumide, improves efficacy of immune checkpoint antibodies in hepatocellular carcinoma

Treatment with a cholecystokinin receptor antagonist, proglumide, improves efficacy of immune checkpoint antibodies in hepatocellular carcinoma

Treatment with a cholecystokinin receptor antagonist, proglumide, improves efficacy of immune checkpoint antibodies in hepatocellular carcinoma

Treatment with a cholecystokinin receptor antagonist, proglumide, improves efficacy of immune checkpoint antibodies in hepatocellular carcinoma

Cholecystokinin Receptor Antagonist Suppresses Melanoma Growth by Inducing Apoptosis of Tumor Cells

Melanoma is a malignant skin tumor with high metastatic activity. Although melanoma has been well-studied, its cellular kinetics remain elusive. The cholecystokinin (CCK) receptor is expressed in various types of tumors because CCK promotes the survival and proliferation of tumor cells. Thus, we hypothesized that the growth of melanoma was positively regulated by signals from the CCK receptor and sought to investigate whether CCK receptor antagonists affect the growth of melanoma cells expressing CCK receptor. Immunohistochemically, the CCK receptor A is expressed in the clinical specimens of melanoma. CCK receptor antagonists decreased the viability of melanoma cells by suppressing cell division and promoting apoptosis. CCK receptor antagonists also decreased the mitochondrial membrane potential through enhanced gene expression of the proapoptotic protein, Bcl2-associated X, and tumor suppressor, p53, suggesting that the antagonist induced the apoptosis of melanoma cells in a mitochondria-dependent manner. In addition, a caspase 3 inhibitor, Z-DEVD-FMK, partially blocked the antiviability of the antagonist, indicating that caspase 3 is involved in antagonist-induced apoptosis. Notably, tumor growth was attenuated when a CCK receptor antagonist was locally administered to the melanoma-bearing mice. Therefore, our study suggests the therapeutic potential of CCK receptor antagonists in the treatment of skin cancer.

The Role of Cholecystokinin Expressing Neurons in Socially Enhanced Pain

Mice that interact with social partners expressing pain behaviors, such as paw licking and guarding, exhibit more pain behavior than mice interacting with social partners exhibiting no pain. When mice are pre-treated with proglumide, an antagonist of cholecystokinin receptors, the elevated pain behavior after interaction with a partner in pain is decreased, indicating involvement of cholecystokinin expressing neurons. The purpose of this study was to uncover the functional role of cholecystokinin expressing neurons in elevated pain responses of mice that interact with social partners expressing pain behaviors. We used immunohistochemistry for c-fos, an early immediate gene that indicates neural activity, to compare activation during behavior between groups, and we used chemogenetics in a CCK-Cre mouse line to explore the necessity of cholecystokinin expressing neurons in socially enhanced pain. We found that c-fos is more highly expressed in the prefrontal cortex and dorsal region of the periaqueductal grey in mice that interaction with partners in pain compared to saline, and that proglumide lowers c-fos expression. Additionally, we show that silencing CCK-expressing neurons during social interaction lowers pain behavior. Our data indicate involvement of prefrontal and midbrain regions in the social enhancement of pain and lend evidence toward the need for cholecystokinin neuronal activity in the social enhancement of pain. Our work aims to build a better understanding neural circuitry underlying social aspects of the biopsychosocial model of pain. Grant support from Canadian Foundation for Innovation 36548 NSERC RGPIN-2016-06284 Ontario Ministry of Innovation ER16-12-060.

Safety and Pharmacokinetic Assessment of Oral Proglumide in Those with Hepatic Impairment.

Proglumide is an orally administered cholecystokinin receptor antagonist that was found to improve nonalcoholic steatohepatitis, reverse liver fibrosis, and decrease incidence of hepatocellular carcinoma (HCC) in animal models. The current investigation aimed to test the pharmacokinetics and safety of proglumide in subjects with hepatic impairment compared with healthy controls. In this translational study, subjects with confirmed cirrhosis, Child-Pugh stage A or B, or healthy controls were recruited for a single-dosing study. Baseline urine and blood samples were obtained before administration of proglumide and also collected after ingestion up to 24 h. Drug concentrations measured by mass spectroscopy revealed peak plasma concentrations (Cmax) of 7847, 9721, and 10,635 ng/mL at about 1 h (Tmax) for healthy controls, subjects with Child-Pugh A, and B cirrhosis, respectively. The serum elimination half time was 3 h. Maximum urine drug concentration (Cmax = ~411 µg/mL) was observed at 3 h, and urinary drug concentration declined at 5 h. There were no adverse events reported, and follow-up liver panels in cirrhosis subjects were unchanged or improved. This investigation demonstrated that proglumide is safe and has similar pharmacokinetic properties in subjects with cirrhosis as in healthy controls; therefore, it will be safe to test the efficacy of proglumide as a therapeutic agent in those subjects with cirrhosis or HCC.

Cholecystokinin Receptor Antagonist Improves Efficacy of Chemotherapy in Murine Models of Pancreatic Cancer by Altering the Tumor Microenvironment.

Simple SummaryOur research team has identified the cholecystokinin-B receptor (or CCK-BR) as a novel target for treatment of pancreatic cancer. CCK-BRs are over-expressed in pancreatic cancer and activation stimulates growth in cell culture and in animal models. CCK-BRs are also expressed on pancreatic stellate cells—or the fibroblasts that are responsible for the dense fibrosis in the tumor microenvironment that impedes the penetration of chemotherapy. We show strong evidence that treatment with a CCK receptor antagonist, proglumide, decreases fibrosis in the pancreatic tumor microenvironment and increases the influx of T-cells rendering chemotherapy-resistant cancer, sensitive to gemcitabine. Mice treated with the combination therapy had fewer metastases and greater survival. Tumors from these mice had higher gemcitabine levels and novel differentially expressed genes by RNA-Seq. Proglumide is an older drug that was developed many years ago for peptic ulcer disease but is no longer in use. Repurposing this older drug may improve survival from this recalcitrant malignancy.Pancreatic cancer is resistant to chemotherapy in part due to the dense desmoplastic fibrosis surrounding the tumor, the immunosuppressive cells in the tumor microenvironment (TME), and the early rate of metastases. In this study, we examined the effects of a CCK receptor antagonist, proglumide, alone and in combination with gemcitabine in murine models of pancreatic cancer. Tumor growth rate, metastases, and survival were assessed in mice bearing syngeneic murine or human pancreatic tumors treated with PBS (control), gemcitabine, proglumide, or the combination of gemcitabine and proglumide. Excised tumors were evaluated histologically for fibrosis, immune cells, molecular markers, and uptake of chemotherapy by mass spectroscopy. Peripheral blood was analyzed with a microRNAs biomarker panel associated with fibrosis and oncogenesis. Differentially expressed genes between tumors of mice treated with gemcitabine monotherapy and combination therapy were compared by RNAseq. When given in combination the two compounds exhibited inhibitory effects by decreasing tumor growth rate by 70%, metastases, and prolonging survival. Proglumide monotherapy altered the TME by decreasing fibrosis, increasing intratumoral CD8+ T-cells, and decreasing arginase-positive cells, thus rendering the tumor sensitive to chemotherapy. Proglumide altered the expression of genes involved in fibrosis, epithelial–mesenchymal transition, and invasion. CCK-receptor antagonism with proglumide renders pancreatic cancer susceptible to chemotherapy.

Pain, Pathophysiological Mechanisms, and New Therapeutic Options for Alternative Analgesic Agents in Sheep: A Review and Investigation.

Simple SummaryThe purpose of this review is to provide current data on the definition and types of pain, describe its neuropharmacological and pathological mechanisms, and present a comparative analysis of the results obtained after intracerebroventricular (ICV) infusion of voltage-gated calcium channel inhibitors (VGCCIs) such as diltiazem, nifedipine, and verapamil, cholecystokinin receptor antagonists (PD, proglumide), and glutamatergic receptor antagonists (L-AP3, DL-AP3) during experimental distension of the duodenal and/or descending colonic wall. This method was used as a model for suppressing pain in sheep based on viscero-visceral inhibitory reflex, measured by the inhibition of behavioral symptoms of stress, degree of reticulo-ruminal motility, and changes in plasma cortisol and catecholamine concentration. After ICV infusion, all tested substances suppressed, to varying degrees, the viscero-visceral inhibitory reflex, tachycardia, hyperventilation, bleating, and gnashing of the teeth, whereas they increased the levels of cortisol and plasma catecholamines in sheep. These substances could be potential non-narcotic agents for the treatment of visceral intestinal pain (intestinal colic) in sheep, but clinical confirmation of the substances’ efficacy for treating intestinal colic is needed.Relief from suffering is the guiding principle of medical and veterinary ethics. Medical care for animals should be carried out to meet all welfare conditions. The need for pain management is demonstrated by recent monographs devoting attention to this urgent ethical need. Little data, however, are available on the prevention and attenuation of pain in sheep. After administration of narcotic analgesics used for severe visceral pain, sheep react with a state of excitement. Therefore, it was decided to experimentally investigate the usefulness of potential non-narcotic drugs to relieve pain in sheep with intestinal colic caused by 10 min of mechanical distension of their duodenal and/or descending colonic wall. The results indicate the potential usefulness of VGCCIs (diltiazem, nifedipine, verapamil), cholecystokinin receptor antagonists (PD, proglumide), and metabotropic glutaminergic receptor antagonists (mGluRAs), such as L-AP3, DL-AP3. As a premedication, these substances prevented the occurrence of symptoms of acute intestinal pain including atony of reticulo-rumen, tachycardia, hyperventilation, moaning, gnashing of teeth, hypercortisolemia, and catecholaminemia; hence, these substances are considered potential agents in the treatment of sheep visceral pain.

Beta-1 blocker reduces inflammation and preserves intestinal barrier function after open abdominal surgery

BackgroundOpen abdominal surgery is frequently related to excessive inflammation and a compromised intestinal barrier, leading to poor clinical outcomes. The administration of beta-1 blocker has been shown to effectively reduce inflammation and preserve intestinal barrier function in patients with sepsis, shock, or other critical illnesses. The underlying mechanism of these effects may be associated with the autonomic nervous system’s activation via cholecystokinin receptors. This study aimed to investigate the effect of beta-1 blocker on systemic and local inflammatory responses and the intestinal barrier function in the context of open abdominal surgery. MethodsA rat model of open abdominal surgery was induced through peritoneal air exposure for 3 hours and treated via gavage with the beta-1 blocker, metoprolol, or saline. Cholecystokinin-receptor antagonists were administered before the metoprolol treatment. Peritoneal lavage fluid, serum, and tissues were collected 24 hours after surgery to determine systemic and local inflammation and intestinal integrity. ResultsThe intervention with metoprolol significantly reduced serum tumor necrosis factor-alpha and interleukin-6 (P < .05) and peritoneal interleukin-6 (P < .01) compared with those of animals treated with saline. The intestinal myeloperoxidase indicating the influx of neutrophils was also significantly prevented by the administration of metoprolol (P < .05). Above all, this intervention resulted in a significant decrease in serum D-lactate and intestinal fatty acid-binding protein, intestinal permeability, bacterial translocation, and Chiu’s score for intestinal mucosa injury (P < .05). However, the anti-inflammatory and intestinal integrity protective effects of metoprolol were prevented by the blockage of cholecystokinin receptors (P < .05). ConclusionOur data indicate that beta-1 blocker reduces systemic and local inflammatory responses and preserves intestinal barrier function after open abdominal surgery through a mechanism that depends on cholecystokinin receptors. Clinically, these findings imply that perioperative intervention with a beta-1 blocker may be an effective new therapy to enhance recovery after open abdominal surgery.

Abstract 5326: Cholecystokinin receptor antagonist decreases fibrosis in pancreatic cancer microenvironment to improve uptake and efficacy of chemotherapy

Abstract Background: Although pancreatic cancer cells respond to chemotherapeutic agents in cell culture, many of these drugs are less effective in vivo. This decreased response to chemotherapy in animal models and human subjects is in part attributed to the dense stroma of the pancreatic tumor microenvironment (TME) that impedes penetration of drugs. Pancreatic stellate cells and tissue fibroblasts have cholecystokinin (CCK) receptors and when these receptors are activated, they promote collagen deposition and increase fibrosis in the TME. We have previously shown that CCK receptor antagonists can decrease fibrosis and change the T-cell infiltrates of the TME in pancreatic tumors. We hypothesized that an oral CCK receptor antagonist, proglumide, would improve the efficacy of gemcitabine by decreasing fibrosis in the TME and improving uptake of chemotherapy. Methods: 500,000 mT3 murine pancreatic cancer cells were injected subcutaneously into the right flank of 40 C57/BL6 female mice. One week after the mice had measurable tumors (baseline), mice were divided into 4 groups (N=10 mice each) with equal mean tumor volumes. Treatment groups included: PBS control (100µl IP twice weekly); proglumide in drinking water (0.1 mg/ml); gemcitabine (100mg/kg, 100µl IP twice weekly); and combination of gemcitabine and proglumide. Tumors were measured weekly and the volumes were calculated. Mice were euthanized per protocol when the tumor diameter reached 20mm; tumors were removed, then flash frozen for gemcitabine measurement via mass spectrometry. Results: Tumor volumes demonstrated a rapid growth rate in the PBS control mice with a slope of 184.2±2 (mm3/week), whereas growth rates for proglumide (75±2) and gemcitabine monotherapy (72±14) were 2.6-fold slower, and also 3.4-fold slower for mice treated with both gemcitabine and proglumide (55.6±12; p&amp;lt;0001). By day 62, when all of the control PBS mice had died, survival in the other groups was: 70% for proglumide, 90% for gemcitabine only, and 100% for the combination-treated mice. On day 87, survival was as follows: control 0%; proglumide 40%, gemcitabine 50%, and the combination group 70%. Mean gemcitabine drug uptake, as measured by mass spectrometry, was 4-times higher in the tumors of mice treated with combination therapy (729 pg/ml) compared to the gemcitabine concentration in tumors of mice treated with monotherapy (173pg/ml). Kaplan Meier survival curve revealed significant improved survival in mice treated with the combination of gemcitabine and proglumide (p=0.001) compared to PBS. Conclusion: CCK receptor blockade with proglumide decreases fibrosis in pancreatic cancer TME allowing greater tumor uptake of gemcitabine and improving efficacy by slowing tumor growth and improving survival. Strategies to improve first-line therapies for patients with pancreatic cancer may improve overall survival of this disease. Citation Format: Zoe X. Malchiodi, Hong Cao, Martha Gay, Sunil Bansal, Benjamin A. Weinberg, Amrita Cheema, Narayan Shivapurkar, Jill P. Smith. Cholecystokinin receptor antagonist decreases fibrosis in pancreatic cancer microenvironment to improve uptake and efficacy of chemotherapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5326.

Abstract 2728: Cholecystokinin receptor antagonist proglumide reverses nonalcoholic steatohepatitis and prevents hepatocellular carcinoma

Abstract Background: The fastest growing cause of cancer related death is hepatocellular carcinoma (HCC), in part due to the rising prevalence of nonalcoholic steatohepatitis (NASH). HCC cases are expected to increase during 2015-2030. Cholecystokinin (CCK), blood levels are increased in those consuming high fat diets and CCK receptors have been identified in normal liver, fibroblasts, and immune cells. Hypothesis: We hypothesize that CCK receptor blockade could decrease NASH and prevent HCC in a mouse model.Methods: We examined whether CCK receptor blockade with proglumide could decrease NASH in the choline deficient ethionine supplemented (CDE)-diet mouse model. Two cohorts of Female C57BL/6 mice (N=65) mice were examined: (1) a preventive study in which mice were treated for 12 and 18 weeks to determine if proglumide could prevent NASH and HCC and (2) a ‘reversal study’ in which histologic and biochemical NASH was induced on a 75% CDE high fat diet for 12 weeks followed by treatment with proglumide for 6 weeks (until week 18) while remaining on the CDE diet to determine if CCK-receptor blockade could reverse NASH once established. Control mice received the same high fat diet with choline and half received proglumide therapy. Results: Alanine aminotransferase, aspartate aminotransferases, and bilirubin were increased in mice on the CDE/Regular (untreated water) diet and these values returned to near normal with proglumide therapy in the prevention study and also reversed after NASH was established. Histologic scoring showed significant decreased inflammation, fibrosis and steatosis in mice on the high fat CDE diet when treated with proglumide. 35% of the mice (N=23) at week 18 developed HCC or dysplastic nodules on the CDE diet while none of the mice in the CDE/proglumide prevention (N=15) or reversal therapy groups (N=15) had HCC. Mice on the lard-control diet had fatty livers at week 18 but no evidence of NASH histologically or biochemically and no HCC. Fibrosis was decreased in mice treated with proglumide as evidence by Masson’s trichrome stain and Western blot for FAP. Gene expression of the liver’s collagen-4, TGFβR11, PDGH-Rβ, and collagen-1α1 as determined by qRT-PCR decreased with proglumide treatment. Control diet fed mice had normal serum tests and fibrosis biomarkers. Conclusion: This data supports our novel hypothesis that CCK receptors play a role in NASH-associated HCC. CCK receptor blockade decreased histologic and biochemical evidence of NASH and prevented HCC. Since proglumide has already been tested in human subjects for peptic ulcer disease decades ago and is known to be orally bioavailable, results of our study could easily be translated into a clinical trial in human subjects to improve NASH to prevent HCC. Supported by AGA Research Foundation, Ruesch Foundation, and a grant from NIH, TL1TR001431 Citation Format: Martha D. Gay, Victor Ciofoaia, Sandeep Nadella, Hong Cao, Matthew Huber, Robin D. Tucker, Narayan Shivapurkar, Bhaskar Kallakury, Alexander H. Kroemer, Jill P. Smith. Cholecystokinin receptor antagonist proglumide reverses nonalcoholic steatohepatitis and prevents hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2728.

RYGB increases the satiating effect of intrajejunal lipid infusions in female rats

We used a novel rat model to investigate the physiological bases of early satiation after Roux-en-Y gastric bypass surgery (RYGB). Female rats were subjected to RYGB or sham surgery. Chronic infusion catheters were placed in the Roux limb of RYGB rats and the corresponding anatomical locus of the jejuna of sham-RYGB rats. Rats were also ovariectomized and chronically treated with either estradiol (E2; 2 μg each 4th day SC) or the oil vehicle. Testing was begun 10–12 wk after surgery. Intrajejunal lipid infusions (10 min, 4.4 mL, 8.8 kcal) were performed just before test meals of a low-energy artificially sweetened gel diet (0.1 kcal/g) that RYGB rats ingest avidly. Intrajejunal lipid infusions reduced test-meal size more in RYGB rats than sham-operated rats, indicating that, at least after prolonged adaptation to surgery, the satiating actions of lipids acting intra- or post-jejunally are increased by RYGB and that accelerated meal appearance in the intestines after RYGB is not necessary for this effect. The satiating effects of intrajejunal lipid infusions were similar in E2-and oil-treated rats, suggesting that the effect was not dependent on an activational effect of estrogens. In a second experiment, pretreatment with the cholecystokinin A-receptor antagonist devazepide reduced the satiating effect of intrajejunal lipid infusions in E2-treated RYGB rats. Although these data are preliminary due to the smaller numbers of rats than in the first experiment, they suggest that cholecystokinin-mediated jejunal satiation contributes to early satiation after RYGB in ovariectomized rats with peri-ovulatory levels of estradiol. The results of these experiments may be relevant to understanding RYGB outcome in pre- and postmenopausal women.

A cholecystokinin receptor antagonist inhibits the osteoarthritis features induced by GPR22 in vitro and in vivo

A cholecystokinin receptor antagonist inhibits the osteoarthritis features induced by GPR22 in vitro and in vivo

Cholecystokinin receptor antagonist alters pancreatic cancer microenvironment and increases efficacy of immune checkpoint antibody therapy in mice.

Advanced pancreatic ductal adenocarcinoma (PDAC) has typically been resistant to chemotherapy and immunotherapy; therefore, novel strategies are needed to enhance therapeutic response. Cholecystokinin (CCK) has been shown to stimulate growth of pancreatic cancer. CCK receptors (CCKRs) are present on pancreatic cancer cells, fibroblasts, and lymphocytes. We hypothesized that CCKR blockade would improve response to immune checkpoint antibodies by promoting influx of tumor-infiltrating lymphocytes (TILs) and reducing fibrosis. We examined the effects of CCKR antagonists or immune checkpoint blockade antibodies alone or in combination in murine models of PDAC. Monotherapy with CCKR blockade significantly decreased tumor size and metastases in SCID mice with orthotopic PDAC, and in C57BL/6 mice, it reduced fibrosis and induced the influx of TILs. Immune-competent mice bearing syngeneic pancreatic cancer (Panc02 and mT3-2D) that were treated with the combination of CCK receptor antagonists and immune checkpoint blockade antibodies survived significantly longer with smaller tumors. Tumor immunohistochemical staining and flow cytometry demonstrated that the tumors of mice treated with the combination regimen had a significant reduction in Foxp3+T-regulatory cells and an increase in CD4+and CD8+lymphocytes. Masson's trichrome stain analysis revealed 50% less fibrosis in the tumors of mice treated with CCKR antagonist compared to controls and compared to checkpoint antibody therapy. CCKR antagonists given with immune checkpoint antibody therapy represent a novel approach for improving survival of PDAC. The mechanism by which this combination therapy improves the survival of PDAC may be related to the decreased fibrosis and immune cells of the tumor microenvironment.

Lack of Analgesic Synergy of the Cholecystokinin Receptor Antagonist Proglumide and Spinal Cord Stimulation for the Treatment of Neuropathic Pain in Rats

Neuropathic pain is difficult to manage and treat. Spinal cord stimulation (SCS) has become an established procedure for treating chronic neuropathic pain that is refractory to pharmacological therapy. In order to achieve better analgesia, a number of studies have evaluated the effectiveness of combining drug therapy with SCS. Cholecystokinin antagonists, such as proglumide, enhance the analgesic efficacy of endogenous opioids in animal models of pain. We previously reported that both systemic and spinal administration of proglumide enhances analgesia produced by both low- and high-frequency transcutaneous electrical nerve stimulation (TENS). Since SCS produces analgesia through endogenous opioids, we hypothesized that the analgesic effect of SCS would be enhanced through co-administration with proglumide in animals with neuropathic pain. Male Sprague-Dawley rats (n = 40) with spared nerve injury were given proglumide (20 mg/kg, i.p.) or saline prior to treatment with SCS (sham, 4 Hz, and 60 Hz). Mechanical withdrawal thresholds of the paw were measured before and after induction of nerve injury, and after SCS. Physical activity levels were measured after SCS. Both proglumide and SCS when given independently significantly increased withdrawal thresholds two weeks after nerve injury. However, there was no additional effect of combining proglumide and SCS on mechanical withdrawal thresholds or activity levels in animals with nerve injury. Proglumide may be a candidate for achieving analgesia for patients with refractory neuropathic pain conditions, but does not enhance analgesia produced by SCS.

A cholecystokinin receptor antagonist inhibits chondrocyte hypertrophy and protein kinase a activity decrease induced by activation of GPR22

A cholecystokinin receptor antagonist inhibits chondrocyte hypertrophy and protein kinase a activity decrease induced by activation of GPR22