Macrophage Inhibitory Cytokine-1 Research Articles

Abstract 2765: Novel WNT-RIP1-GDF15 pathway promotes migration and invasion of colorectal cancer cells

Abstract Growth-differentiation factor 15 (GDF15) is a member of the transforming growth factor β (TGF-β) family protein, also known as NSAID-activated gene 1 (NAG-1) or macrophage inhibitory cytokine 1 (MIC-1), and is a major cause of cancer cachexia, cardiovascular disease, and various inflammatory diseases. Roles of GDF15 as major inflammatory response factor also have been demonstrated in animal models, and it has also showed various malignant functions such as regulating metabolism, promoting metastasis by inducing EMT in cancer. Here, we revealed a novel potential role for RIP1 in colorectal cancer (CRC) in enhancing metastasis by controlling WNT-RIP1-GDF15 signaling. We showed that WNT3A treatment increased the expression of GDF15 and GFRAL. Immunohistochemical analysis of human CRC tissue arrays consisting of primary cancer and metastatic cancer also confirmed that the expression of GDF15 and GFRAL was increased in metastatic cancer. Human XL cytokine assay, western blot, and ELISA results confirmed that GDF15 expression was reduced in cell lines in which RIP1 was knocked down. Reduction of GDF15 expression and secretion by RIP1 knockdown showed suppression of EMT induction resulting to decrease of migration and invasion of CRC cells. Taken together, these results suggest a novel EMT-enhancing role for RIP1 in the WNT pathway and suggest a novel WNT-RIP1-GDF15 pathway contributing to CRC malignancy by promoting EMT. Citation Format: A-Ram Kang, Do Hoon Kim, Jong Kuk Park. Novel WNT-RIP1-GDF15 pathway promotes migration and invasion of colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2765.

Population Pharmacokinetic and Pharmacodynamic Analysis of Navtemadlin in Patients with Relapsed and Refractory (R/R) Myelofibrosis (MF) and Other Myeloid or Solid Tumor Malignancies

Background:Murine double minute 2 (MDM2), a key negative regulator of the tumor suppressor protein p53, is overexpressed in malignancies such as MF and Merkel cell carcinoma (MCC). Navtemadlin is a potent, selective, orally available MDM2 inhibitor that overcomes MDM2 dysregulation by restoring p53 activity and inducing apoptosis of TP53WT tumors. Navtemadlin has been tested in 21- or 28-day treatment cycles, with 5 or 7 consecutive days of dosing per cycle. Navtemadlin elicits plasma concentration-dependent increases in serum macrophage inhibitory cytokine-1 (MIC-1). An increase in MIC-1 relative to baseline MIC-1 serum concentration is a key pharmacodynamic (PD) marker of response to navtemadlin treatment (Zhang et al. Xenobiotica 2022). A population pharmacokinetic (PK) model was developed, based on patients with R/R MF (N=113, NCT03662126); MCC (N=35, NCT03787602); solid tumors and multiple myeloma (ST/MM N=105, Gluck et al. Invest New Drugs 2019); R/R acute myeloid leukemia (AML, N=35, Erba et al. Blood Adv 2019); and healthy volunteers (HV, N=30, Wong et al. Clin Pharmacol Drug Dev 2022).The objectives wereto characterize navtemadlin PK and covariate effects and compare steady-state (SS) PK and PD across cancer types. Methods:A two-compartment PK model with first-order absorption and elimination was estimated using NONMEM ® (first-order conditional estimation with interaction). Four transit compartments captured absorption. Inter-subject variability was modeled as lognormal. A stepwise covariate search used forward addition (p<0.05) followed by backward elimination (p<0.01). Log-transformed SS MIC-1 ratio to baseline (fold ratio) was tested in a fixed-effects linear regression model with respect to SS exposures, with baseline MIC-1 as the covariate. The final population PK and MIC-1 models were evaluated by inspection of parameter tables, by overlaying model predictions with observed data, and by standard residual diagnostics. Results:The PK estimation used 5,282 concentrations from 318 subjects, including 1,415 concentrations in 113 patients with R/R MF. Tumor type affected absorption rate (median, 0.635/hr in MCC; slower vs other types), apparent clearance (median, 8.90 L/hr in MCC; lower vs other types), and apparent central volume (median, 64.4 L in MCC; similar to AML, but lower vs other types) (Table 1). Accordingly, simulated SS area under the curve (AUCss) differed across populations in the order MCC>AML>MF>ST/MM = HV (Figure 1). Covariate analysis indicated median AUC increased with the inflammation marker C-reactive protein, by 21% at 90 th percentile CRP, and with age, by 5% at 90 th percentile age of 75 y, compared to the median, 66 y. Men had 24% lower relative bioavailability than women. Taking navtemadlin with food slowed absorption by 10% but had no impact on AUCss. Other tested covariates, including body weight, creatinine clearance, aspartate transaminase, alanine transaminase, bilirubin, albumin, alpha 1-acid glycoprotein, race, UGT1A1 genotype, recent ruxolitinib treatment in MF, and CYP3A4 inducer/inhibitor concomitant medications, were not significant. Median MIC-1 fold ratio increased with navtemadlin AUCss. Higher baseline MIC-1 resulted in lower SS MIC-1 fold ratio. Median baseline MIC-1 differed by tumor type. In R/R MF, baseline MIC-1 was 2,297 ng/L and SS fold ratio of MIC-1 was 7.79 (N=91). In MCC, baseline MIC-1 was 1,718 ng/L and SS fold ratio of MIC-1 was 16.7 (N=29). In R/R MF, higher baseline spleen volume was also associated with lower SS MIC-1 fold ratio. Exposure-MIC-1 relationships in R/R MF and MCC were generally similar to other tumor types and HV populations (Allard et al. Hemasphere 2019; Zhang et al. Xenobiotica 2022). Conclusions:Tumor type influenced navtemadlin exposure with simulated exposure in R/R MF patients at the selected Phase 3 dose of 240 mg comparable to exposures in MCC patients at 180 mg, the selected Phase 2 dose for that indication. Cancer-associated inflammation and/or treatment history, as well as age and female sex, may increase navtemadlin exposure. The PD marker MIC-1 responds to navtemadlin in a concentration-dependent fashion. The overall SS fold change of MIC-1 PD responses was lower in disease states or subjects with higher baseline MIC-1. These studies demonstrate potent, dose-dependent PK/PD responses following p53 activation with the novel MDM2 inhibitor, navtemadlin, across diverse tumor types.

83P Evaluation of serum macrophage inhibitory cytokine 1 as a diagnostic biomarker for pancreatic cancer: A systematic review and diagnostic accuracy meta-analysis

83P Evaluation of serum macrophage inhibitory cytokine 1 as a diagnostic biomarker for pancreatic cancer: A systematic review and diagnostic accuracy meta-analysis

Cytokines as Prognostic Biomarkers in Osteosarcoma Patients: A Systematic Review and Meta-analysis.

Osteosarcoma is the most prevalent type of primary bone malignancy in children and adolescents. The effect of cytokines on osteosarcoma prognosis has been studied and reported. This meta-analysis aimed to assess the prognostic value of cytokines as osteosarcoma biomarkers. Databases including PubMed, Embase, and Cochrane Library were searched for studies on the prognostic value of cytokines in osteosarcoma. From the eligible studies, data on overall survival (OS), disease-free survival, and metastasis-free survival (MFS) were extracted. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. A total of 11 studies involving 755 patients were included in this analysis. High macrophage migration inhibitory factor (MIF) expression in tumors was significantly associated with shortened OS (HR = 2.01, 95% CI: 1.18-3.42, P = 0.010) and MFS (HR = 2.51, 95% CI: 1.47-4.01, P = 0.001). Elevated T cell immunoglobulin and mucin domain-3 (Tim-3) levels in serum correlated with increased risk of disease progression in patients with osteosarcoma (HR = 3.14, 95% CI: 2.88-3.03, P < 0.001). However, interleukin 6 (IL-6) and tumor necrosis factor were not substantially associated with osteosarcoma prognosis. Owing to a paucity of research, other relevant cytokines [interferon-α/β receptor, tissue factor, macrophage inhibitory cytokine 1 (MIC-1), and IL-23] could not be combined. In conclusion, MIF levels in tumors and Tim-3 levels in serum can be potential biomarkers of poor prognosis in osteosarcoma. To confirm this finding and implement these biomarkers into clinical applications, additional large-scale, high-quality studies are needed.

Astaxanthin inhibits oxidative stress and apoptosis in diabetic retinopathy

BackgroundThe pathophysiology of diabetic retinopathy (DR) is thought to be influenced by oxidative stress. Astaxanthin (ASX) is a natural product with antioxidant effect, but it is not clear whether its mechanism of inhibiting the development of DR is related to anti-oxidation. MethodsRats were intraperitoneally injected with streptozotocin (60 mg/kg) to create DR rat models followed by ASX (20 mg/kg) for 45 days. Retinal tissue was examined by Hematoxylin and Eosin staining. By using Enzyme-linked immunosorbent assay (ELISA), 2,7-Dichlorodrhydrofluorescein diace (DCFH-DA) probes, immunohistochemistry and western blot, it was feasible to evaluate the contents of inflammation-related factors (tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and macrophage inhibitory cytokine-1 (MIC-1)), oxidative stress-related indicators (glutathione (GSH), malonic dialdehyde (MDA), glutathione peroxidase (GPx), reactive oxygen species (ROS) and Total antioxidant capacity (T-AOC)), antioxidant enzymes (hemoxgenase-1(HO-1) and Quinone Oxidoreductase 1 (NQO1)), and apoptosis-related proteins (Bcl-2, Bcl2 Associated X Protein (BAX), and cleaved-caspase-3). Additionally, antioxidant proteins downstream of the nuclear factor E2 related factors (Nrf-2) pathway, expression levels of Nrf2/ Kelch-like ECH-associated protein 1(Keap 1) pathway-associated proteins, and nuclear and cytoplasmic levels of Nrf2 were assessed using immunohistochemistry, western blot, or quantitative real-time polymerase chain reaction (qRT-PCR). ResultsASX alleviated retinal tissue damage by increasing overall retina thickness and ganglion cell layer (GCL) cell numbers and exerted the anti-inflammatory, anti-oxidative stress, and anti-apoptosis effects in DR rats. Additionally, ASX could inhibit the expression of Keap1, promote the transport of Nrf2 from cytoplasm to nucleus and facilitate the expressions of HO-1, NQO1, γ-glutamylcysteine synthetase, (γ-GCS) and GPx. ConclusionASX exerted antioxidant effects through Nrf2/keap1 pathway, thereby alleviating apoptosis, inflammation, and oxidative stress in retinal tissues of DR rats.

Macrophage inhibitory cytokine-1 aggravates diet-induced gallstone formation via increased ABCG5/ABCG8 expression.

Macrophage inhibitory cytokine 1 (MIC-1), which is overproduced in various human cancers and associated with cachexia, acts on the hypothalamus to suppress appetite and reduce body weight. We investigated the mechanisms through which MIC-1 affects bile acid metabolism and gallstone formation, which are poorly understood. Over 6 weeks, male C57BL/6 mice fed either standard chow or a lithogenic diet were intraperitoneally injected with phosphate-buffered saline (PBS) or MIC-1 (200 μg/kg/week). Among lithogenic diet-fed mice, MIC-1 treatment resulted in increased gallstone formation compared with PBS treatment. Compared with PBS treatment, MIC-1 treatment decreased hepatic cholesterol and bile acid levels and reduced expression of HMG-CoA reductase (HMGCR), the master cholesterol metabolism regulator sterol regulatory element-binding protein 2, cholesterol 7α-hydroxylase (CYP7A1), mitochondrial sterol 27-hydroxylase, and oxysterol 7α-hydroxylase. Compared with PBS treatment, MIC-1 treatment had no effect on small heterodimer partner, farnesoid X receptor, or pregnane X receptor expression, and extracellular signal-related kinase and c-Jun N-terminal kinase phosphorylation decreased, suggesting that these factors do not contribute to the MIC-1-induced reduction in CYP7A1 expression. Compared with PBS treatment, MIC-1 treatment increased AMP-activated protein kinase (AMPK) phosphorylation. Treatment with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) reduced CYP7A1 and HMGCR expression, whereas the AMPK inhibitor Compound C reversed MIC-1-induced reductions in CYP7A1 and HMGCR expression. Furthermore, in MIC-1-treated mice, total biliary cholesterol levels increased together with increased ATP-binding cassette subfamily G (ABCG)5 and ABCG8 expression. Compared with PBS treatment, MIC-1 treatment did not affect expression of liver X receptors α and β, liver receptor homolog 1, hepatocyte nuclear factor 4α, or NR1I3 (also known as constitutive androstane receptor), which are upstream of ABCG5/8; however, MIC-1 treatment increased ABCG5/8 expression and promoter activities. Our study indicates that MIC-1 influences gallstone formation by increasing AMPK phosphorylation, reducing CYP7A1 and HMGCR expression, and increasing ABCG5 and ABCG8 expression.

Metformin and growth differentiation factor 15 (GDF15) in type 2 diabetes mellitus: A hidden treasure.

Type 2 diabetes mellitus (T2DM) is a chronic endocrine disorder due to the reduction of insulin sensitivity and relative deficiency of insulin secretion. Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor beta (TGF-β) superfamily and was initially identified as macrophage inhibitory cytokine-1 (MIC-1). GDF15 is considered a cytokine with an anti-inflammatory effect and increases insulin sensitivity, reduces body weight, and improves clinical outcomes in diabetic patients. GDF15 acts through stimulation of glial-derived neurotrophic factor (GDNF) family receptor α-like (GFRAL), which is highly expressed in the brain stem to induce taste aversion. Metformin belongs to the group of biguanides that are derived from the plant Galega officinalis. It is interesting to note that metformin is an insulin-sensitizing agent used as a first-line therapy for T2DM that has been shown to increase the circulating level of GDF15. Thus, the present review aims to determine the critical association of the GDF15 biomarker in T2DM and how metformin agents affect it. This review illustrates that metformin activates GDF15 expression, which reduces appetite and leads to weight loss in both diabetic and nondiabetic patients. However, the present review cannot give a conclusion in this regard. Therefore, experimental, preclinical, and clinical studies are warranted to confirm the potential role of GDF15 in T2DM patients.

Abstract 10494: Proteomic Assessment of Novel Kidney Function Biomarkers in Heart Failure: A Community Study

Introduction: Heart failure (HF) is a complex syndrome with high mortality often associated with impaired kidney function. Estimated glomerular filtration rate (eGFR) is central to kidney function assessment in HF. However, novel proteins related to kidney function (lipocalin 2 [LCN2], macrophage inhibitory cytokine 1 [MIC1], T cell immunoglobulin and mucin domain 1 [TIM1]) may improve risk stratification of HF patients, beyond eGFR. Their prognostic contribution remain to be fully explored. Hypothesis: Proteomic assessment of kidney function biomarkers improves risk stratification in HF. Methods: Clinical data and biospecimens were collected from a HF community cohort in Southeastern Minnesota from 2003-2012. Serum creatinine was measured in 1,388 patients and eGFR was calculated with the 2021 Chronic Kidney Disease (CKD) Epidemiology Collaboration equation. CKD was defined as an eGFR &lt;60 mL/min/1.73m 2 . Plasma proteins were measured using the SomaLogic aptamer-based technology SomaScan®. In HF patients with and without CKD, Cox proportional hazard models were used to estimate the association between kidney function biomarkers and mortality, after adjustment for Meta-Analysis Global Group in Chronic HF (MAGGIC) risk score. Results: At HF index, patients were on average 75±13 years of age and 48% female. Patients had a median eGFR of 57 mL/min/1.73m 2 and 64% had CKD. Adjusted geometric mean levels of LCN2, MIC1, and TIM1 levels were 20-30% higher in patients with CKD. Patients with CKD were at higher risk of dying (HR 1.6, 95% CI 1.4-1.8). Patients with above median levels of LCN2, TIM1, MIC1 were at higher risk of dying, irrespective of CKD (See Figure). Conclusions: In a HF community cohort, several novel kidney function biomarkers provided further risk stratification in patients with and without CKD.

Antibiotic-disrupted ribosome biogenesis facilitates tumor chemokine superinduction

Upon exposure to internal or external stressors, ribosomes stand sentinel via modulation of ribosome assembly and protein translation. Ribosome-dependent cellular dysfunctions have been associated with pathophysiological processes during inflammation and tumorigenesis. In the present study, ribosome biogenesis was assessed to determine its effects on tumor chemokines, potentially contributing to cancer cell malignant features. In particular, ribosome biogenesis inhibition by antibiotic actinomycin D (ActD) enhanced the expression of chemokines in intestinal cancer cells under endoplasmic reticulum stress that governs multiple pro-tumoral reprogramming. Mechanistically, ribosome biogenesis inhibition superinduced proinflammatory chemokines via transcriptional and post-transcriptional regulation. Moreover, ribosomal stress-responsive p53 and its target macrophage inhibitory cytokine 1 (MIC-1) mediated chemokine superinduction by activating TGF-β–activated kinase 1 (TAK-1) and nuclear factor-kappa B (NF-κB) in intestinal cancer cells. Cancer cell-based regulation of chemokine induction via MIC-1 signaling was verified using clinical transcriptome datasets. Clinical tumor tissue-derived MIC-1 was a positive regulator of chemokines and genes involved in the ribosome biogenesis pathway, supporting the in vitro assessments. Moreover, MIC-1-correlated chemokine expressions predicted poor prognoses in patients with colorectal cancer. Ribosome-based chemokine regulation via MIC-1 signaling would provide novel insights into translational interventions against malignant inflammatory insults.

136 (PB126) - ALRN 6924 induces cell cycle arrest in bone marrow stem cells and hair follicles with dose-dependent degree and duration of effects after a single infusion in healthy volunteers

Background: ALRN-6924 is a cell-permeating, stabilized alpha-helical peptide that binds to endogenous p53 inhibitors MDMX and MDM2, thereby activating p53 and its transcriptional target p21 to cause cell cycle arrest (CCA). This effect is limited to cells with wild-type, functional p53. For cancer patients with tumors bearing mutated p53, ALRN-6924 treatment selectively induces CCA in normal cells, allowing chemotherapy to preferentially target p53-mutant cancer cells that are actively cycling. Materials and methods: A Phase 1 study in heathy volunteers is being conducted to evaluate ALRN-6924 pharmacokinetics (PK) and pharmacodynamics (PD). In Part 1 (37 subjects; Voors-Pette et al, ESMO 2021) it was shown that a 1-hour intravenous (IV) ALRN-6924 infusion was safe, well tolerated, and transiently upregulates p21 in human bone marrow (BM) cells with minimal signal for apoptosis. In Part 2, we aim to directly measure dose-dependent CCA in the BM as well as in hair follicles (HFs) in female subjects across a range of doses by 1-hour IV infusion and 3-minute bolus IV injection. ALRN-6924 was administered as a single IV infusion or bolus injection at 0 (placebo), 0.3, 0.6, or 0.9 mg/kg to cohorts of 3 to 5 subjects. Subjects were evaluated for safety and tolerability. Plasma and serum samples were obtained to determine PK and levels of macrophage inhibitory cytokine-1 (MIC-1), a biomarker of p53 activation. BM was sampled 12 hours post-dose to directly measure CCA by flow cytometry in CD34+, lineage-negative BM stem cells. Occipital scalp skin was sampled by 2 mm punch biopsy for p21 immunohistochemistry in HFs. Results: As of June 20, 2022, 42 subjects (ages 18–59; 100% female) were enrolled and evaluated in Part 2. Subjects experienced only mild, transient adverse events (AEs), with nausea/vomiting as the most frequent related AEs. The degree and duration of serum MIC-1 elevation was dose-dependent. At 12 hours post-dose, the proportion of cycling BM stem cells was significantly reduced at all dose levels, while blinded pathology review suggested ALRN-6924-dependent p21 induction in anagen-phase HFs. Safety profiles, PK and PD were similar for both bolus and infusion. Conclusions: ALRN-6924 shows a favorable safety profile for use as a chemoprotection agent. CCA measured in BM supports prevention of chemotherapy-induced neutropenia, thrombocytopenia, and anemia, while HF results support chemoprotection for alopecia. Administration by IV bolus may simplify dosing vs. the current 1-hr infusion clinical regimen. The dose-dependent degree and duration of effects support development of a universal treatment schedule for broad use across cancer indications and types of chemotherapy. Conflict of interest: Ownership: Manuel Aivado, Vojislav Vukovic, and Allen Annis are employees and shareholders of Aileron Therapeutics Advisory Board: Ulrich Steidl is a member of the Scientific Advisory Board of Aileron Therapeutics Other Substantive Relationships: Britta Will and Kevin Randall are consultants to Aileron Therapeutics

Transforming Growth Factor-Beta Signaling in Cancer-Induced Cachexia: From Molecular Pathways to the Clinics.

Cachexia is a metabolic syndrome consisting of massive loss of muscle mass and function that has a severe impact on the quality of life and survival of cancer patients. Up to 20% of lung cancer patients and up to 80% of pancreatic cancer patients are diagnosed with cachexia, leading to death in 20% of them. The main drivers of cachexia are cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), macrophage inhibitory cytokine 1 (MIC-1/GDF15) and transforming growth factor-beta (TGF-β). Besides its double-edged role as a tumor suppressor and activator, TGF-β causes muscle loss through myostatin-based signaling, involved in the reduction in protein synthesis and enhanced protein degradation. Additionally, TGF-β induces inhibin and activin, causing weight loss and muscle depletion, while MIC-1/GDF15, a member of the TGF-β superfamily, leads to anorexia and so, indirectly, to muscle wasting, acting on the hypothalamus center. Against this background, the blockade of TGF-β is tested as a potential mechanism to revert cachexia, and antibodies against TGF-β reduced weight and muscle loss in murine models of pancreatic cancer. This article reviews the role of the TGF-β pathway and to a minor extent of other molecules including microRNA in cancer onset and progression with a special focus on their involvement in cachexia, to enlighten whether TGF-β and such other players could be potential targets for therapy.

Clinical usefulness and acceleratory effect of macrophage inhibitory cytokine-1 on biliary tract cancer: an experimental biomarker analysis

BackgroundBiliary tract cancer (BTC) has a poor prognosis; therefore, useful biomarkers and treatments are needed. Serum levels of macrophage inhibitory cytokine-1 (MIC-1), a member of the TGF-β superfamily, are elevated in patients with pancreaticobiliary cancers. However, the effect of MIC-1 on BTC is unknown. Therefore, we investigated the effect of MIC-1 on BTC and assessed whether MIC-1 is a biomarker of or therapeutic target for BTC.MethodsMIC-1 expression in BTC cells was determined by performing histological immunostaining, tissue microarray (TMA), western blotting, and reverse transcription PCR (RT–PCR). Cell culture experiments were performed to investigate the effect of MIC-1 on BTC cell lines (HuCCT-1 and TFK-1). The relationships between serum MIC-1 levels and either the disease state or the serum level of the apoptosis marker M30 were retrospectively verified in 118 patients with pancreaticobiliary disease (individuals with benign disease served as a control group, n = 62; BTC, n = 56). The most efficient diagnostic marker for BTC was also investigated.ResultsMIC-1 expression was confirmed in BTC tissue specimens and was higher in BTC cells than in normal bile duct epithelial cells, as determined using TMA, western blotting and RT–PCR. In cell culture experiments, MIC-1 increased BTC cell proliferation and invasion by preventing apoptosis and inhibited the effect of gemcitabine. In serum analyses, serum MIC-1 levels showed a positive correlation with BTC progression and serum M30 levels. The ability to diagnose BTC at an early stage or at all stages was improved using the combination of MIC-1 and M30. The overall survival was significantly longer in BTC patients with serum MIC-1 < the median than in BTC patients with serum MIC-1 ≥ the median.ConclusionsMIC-1 is a useful diagnostic and prognostic biomarker and might be a potential therapeutic target for BTC.

Abstract 2418: Markers for metastasis evaluation of the ErbB family and GDF15 inratosteosarcoma

Abstract The most recent advance in the treatment of osteosarcoma (OS) occurred in the 1980s when multi-agent chemotherapy was shown to improve overall survival compared to surgery alone. Animal model investigations can accelerate the understanding of human diseases and since few models are available for OS, we refined a rat model to ask questions regarding pathways of metastasis and metastasis biomarker predictiveness. The outbred Sprague-Dawley (SD) rat model is an immunocompetent, syngeneic model, as we implant UMR106 OS cells (ATCC), which were originally isolated from a SD OS. We developed a reproducible method to orthotopically implant cells into the tibia microenvironment and to amputate the limb for longitudinal studies. Using young rats, we also modeled pediatric OS. We found that rats develop reproducible primary and metastatic pulmonary tumors which histologically resemble human primary and metastatic osteosarcoma. Using immunohistochemistry methods, we found that primary OS is infiltrated with numerous macrophages with relatively fewer CD3+ T cells. A protein expression survey of these OS cells revealed significant expression of ErbB family receptor tyrosine kinases (ErbB2, ErbB4), which have recently been shown to be anti-inflammatory against macrophages. We also discovered that rats with osteosarcoma have markedly high serum levels of Growth Differentiation Factor 15 (GDF15), also called Macrophage Inhibitory Cytokine 1, a member of the TGF beta family of proteins, which is also frequently expressed with ErbB2 in cancers. GDF15 was measured by ELISA. Western blot analysis showed that GDF15 precursor (pro-peptide) was expressed in primary and metastases. This model will enable studies with anti-ErbB2 or GDF15 pathway inhibition to assess the role of macrophage activation in the setting of pathway inhibition and chemotherapy, as well as how pathway inhibition modulates metastasis incidence. In vivo and invitro, systems will enable the assessment of the role of GDF15 as a potential biomarker of metastasis, compared to tibial radiographic patterns, serum alkaline phosphatase, and lung histopathology. In conclusion, we have an immunocompetent, syngeneic orthotopic osteosarcoma rat model which affectively resembles human osteosarcoma, and can be used for better understanding metastasis mechanisms and metastasis biomarkers. Citation Format: Shun Ishiyama, Bailey West, Hyo-Jeong Han, Xin Guo, Tomoaki Ito, Harumi Saeki, Malcolm V. Brock, Kathleen Gabrielson. Markers for metastasis evaluation of the ErbB family and GDF15 inratosteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2418.

A population pharmacokinetic-pharmacodynamic model of navtemadlin, its glucuronide metabolite (M1) and serum macrophage inhibitory cykokine-1 (MIC-1)

Navtemadlin is a potent, selective, orally available inhibitor of murine double minute 2 that restores p53 activity to induce apoptosis in TP53 wild-type malignancies. Using richly sampled pharmacokinetic (PK) and pharmacodynamic (PD) data from healthy volunteers, a population PK/PD model was developed. A population PK (PPK) model described the PK characteristics of navtemadlin and its major metabolite acyl glucuronide (M1) and quantified enterohepatic recirculation (EHR). Post hoc individual PK parameters from this model were coupled with PD data for serum macrophage inhibitory cytokine-1 (MIC-1, GDF15), a cytokine biomarker of p53 activation, to construct a population PK/PD model that described plasma concentration-driven MIC-1 excursions and enabled simulation of the extent and duration of navtemadlin PD effects. The median apparent clearance (CL/F) and apparent central volume (V2/F) of navtemadlin were 36.4 L/hr and 159 L. The typical maximum stimulatory effect (Smax) was close to the median maximum MIC-1 ratio to baseline of 7.29 in observed data. Simulation revealed a dose-dependent increase of MIC-1 with steady state attained in approximately 7 days, in a 7-day-on/21-day-off dose regimen. Elevated MIC-1 concentrations persist through 17–19 days, leaving about 9-11 PD-free days in a 28-day cycle.

Prognostic value of circulating macrophage inhibitory cytokine 1-growth differentiation factor 15 (MIC-1/GDF15) in obesity: Relation with vascular endothelial growth factor (VEGF) and markers of oxidative stress.

Background: Macrophage inhibitory cytokine 1-Growth differentiation Factor 15 (MIC-1/GDF15) and vascular endothelial growth factor (VEGF) are novel regulators of obesity and energy homeostasis and food intake. Aims: In the current cross-sectional study, we aimed to evaluate MIC-1 and VEGF concentrations and their association with serum lipids and biomarkers of oxidative stress in obese individuals. Methods: Fifty six obese subjects, aged between 20-50 years old, participated in the current study. Anthropometric and nutritional parameters were assessed and serum and blood concentrations of MIC-1/GDF15, VEGF, markers of oxidative stress and serum lipids were evaluated. Results: Serum VEGF was strongly associated with serum lipids and MIC-1/GDF15 concentrations while serum MIC-1/GDF15 was associated with total cholesterol (TC) and VEGF levels. In multivariate regression analysis, serum VEGF, appetite and GPX were potent determinants of MIC-1/GDF15 concentrations while VEGF was only associated with serum MIC-1/GDF15. Conclusion: The findings of the current study demonstrated the association between MIC-1/GDF15 and VEGF. Moreover, a positive association between these cytokines and serum lipids, was also observed. The results suggest that MIC-1/GDF15 and VEGF might be considered as prognostic markers in obesity-related metabolic disorders. Although further mechanistic studies are needed to better clarify the underlying mechanism.

Pharmacokinetics and Macrophage Inhibitory Cytokine-1 Pharmacodynamics of the Murine Double Minute 2 Inhibitor, Navtemadlin (KRT-232) in Fed and Fasted Healthy Subjects.

This single 60‐mg dose, 4‐period crossover study assessed the effect of food and formulation change on navtemadlin (KRT‐232) pharmacokinetics (PK) and macrophage inhibitory cytokine‐1 (MIC‐1) pharmacodynamics. Healthy subjects (N = 30) were randomized to 3 treatment sequences, A: new tablet, fasted (reference, dosed twice); B: new tablet, 30 minutes after a high‐fat meal (test 1); C: old tablet, fasted (test 2). PK/pharmacodynamic parameters were measured over 0 to 96 hours. Adverse events were mild without any discontinuations. No serious adverse events or deaths occurred. In treatment A, navtemadlin mean (coefficient of variation) maximum concentration (Cmax) was 525 (66) ng/mL, at median time to maximum concentration (tmax) of 2 hours. Mean (coefficient of variation) area under the plasma concentration–time curve from time 0 to time t (AUC0‐t) was 3392 (63.3) ng • h/mL, and arithmetic mean terminal half‐life was 18.6 hours. Acyl glucuronide metabolite (M1)/navtemadlin AUC0‐t ratio was 0.2, and urine excretion of navtemadlin was negligible. After a meal (B vs A), navtemadlin tmax was delayed by 1 hour. Geometric least squares means ratios (90%CI) for navtemadlin Cmax and AUC0‐t were 102.7% (87.4‐120.6) and 81.4% (76.2‐86.9), respectively. Old vs new tablet fasted formulations (C vs A) had geometric least squares means ratios (90%CI) of 78.4% (72.0‐85.3) for Cmax and 85.9% (80.5‐91.7) for AUC0‐t. MIC‐1 Cmax and AUC were comparable across groups; tmax was delayed relative to navtemadlin tmax by ≈8 hours. Navtemadlin AUC0‐t and MIC‐1 AUC0‐t correlated significantly. In conclusion, navtemadlin can be administered safely with or without food; the new formulation does not affect navtemadlin PK. The 60‐mg navtemadlin dose elicited a reproducible and robust MIC‐1 response that correlated well with navtemadlin exposure, indicating that murine double minute 2 target engagement leads to p53 activation.

The effect of bariatric surgery on the expression of Growth Differentiation Factor-15/Macrophage-Inhibitory Cytokine-1 (GDF-15/MIC-1) in rat.

Reduced appetite and loss of preference to nutrition dense high-fat diet are present after bariatric surgery. But the mechanism responsible for these changes in biological activities remains unclear. Similar changes in biological activities have been observed with growth/differentiation factor-15/macrophage-inhibitory cytokine-1 (GDF-15/MIC-1) treatment alone. To assess the effect of bariatric surgery on GDF-15/MIC-1expression and circulating level in rodent model. The Affiliated Hospital of Xuzhou Medical University, Xuzhou Jiangsu 221,006, P. R. China. Among 40 fatty Sprague-dawley (SD) rats, 30 randomly receive low-dose STZ to induced diabetes and were randomly assigned to Roux en Y gastric bypass (RYGB, n = 10), Sleeve gastrectomy (SG, n = 10), and SHAM (n = 10). The remaining fatty SD rats were assigned to Normal control (NC, n = 10). Rats were followed for 8weeks postoperatively. Circulating levels of GDF15 and tissue (gastrointestinal and liver) expression were assessed after surgery. Preoperative oral glucose tolerance test (OGTT), and Insulin tolerance test (ITT) were reassessed postoperatively. Changes in bodyweight and food intake were also recorded. Bariatric surgery significantly increased circulating plasma level of GDF15 (p < 0.05). Postoperatively, tissue expression of GDF15 was significantly higher in the stomach pouch, jejunum, and ileum of rats in the RYGB group as well as ileum of rats in the SG group compared to Sham and NC (p < 0.05). Higher Expression of GDF15 in the stomach pouch of the SG group was not statistically significant compared to the stomach of Sham and NC group. GDF15 expression in the liver was significantly less in the RYGB group (p < 0.05). Bariatric surgery significantly increases circulating levels and gastrointestinal tissue expression of GDF15. Given that GDF15 is an important regulator of energy homeostasis, further studies are needed to ascertain the relevance in bariatric surgery.

Growth differentiation factor 15 is an early predictor for persistent organ failure and mortality in acute pancreatitis

ObjectivesEarly prediction of persistent organ failure (POF) is crucial for patients with acute pancreatitis (AP). Growth differentiation factor 15 (GDF15), also known as macrophage inhibitory cytokine 1 (MIC-1), is associated with inflammatory responses. We investigated changes in plasma GDF15 and assessed its predictive value in AP. MethodsThe study included 290 consecutive patients with AP admitted within 36 h after symptoms onset. Clinical data obtained during hospitalization were collected. Plasma GDF15 levels were determined using enzyme-linked immunosorbent assays. The predictive value of GDF15 for POF was analyzed. ResultsThere were 105 mild, 111 moderately severe, and 74 severe AP patients. Plasma GDF15 peak level were measured on admission, and significantly declined on the 3rd and 7th day. Admission GDF15 predicted POF and mortality with areas under the curve (AUC) of 0.847 (95% confidence interval [CI] 0.798–0.895) and 0.934 (95% CI 0.887–0.980), respectively. Admission GDF15, Bedside Index of Severity in Acute Pancreatitis, and hematocrit were independent factors for POF by univariate and multivariate logistic regression, and the nomogram built on these variables showed good performance (optimism-corrected c-statistic = 0.921). The combined predictive model increased the POF accuracy with an AUC 0.925 (95% CI 0.894–0.956), a net reclassification improvement of 0.3024 (95% CI: 0.1482–0.4565, P < 0.001), and an integrated discrimination index of 0.11 (95% CI 0.0497–0.1703; P < 0.001). ConclusionsPlasma GDF15 measured within 48 h of symptom onset could help predict POF and mortality in AP patients.

Macrophage inhibitory cytokine-1 produced by melanoma cells contributes to melanoma tumor growth and metastasis in vivo by enhancing tumor vascularization.

Macrophage inhibitory cytokine-1 (MIC-1) has been reported to be elevated in various human cancers including melanoma; however, the function of MIC-1 in cancer remains unclear. In this study, we attempt to clarify the role of MIC-1 in tumor pathogenesis by employing the orthotopic B16F1 melanoma mouse model in which serum MIC-1 levels are positively correlated with tumor size. By stably transfecting a MIC-1 expression construct into B16F1 melanoma cells, we increased the expression and secretion levels of MIC-1. This increase in MIC-1 expression significantly enhanced the growth of tumors derived from B16F1 cells in vivo, despite not affecting in vitro cell growth. The elevated MIC-1 expression in B16F1 cells also resulted in lymph node metastasis in B16F1 tumor-bearing mice, significantly increasing mortality. Interestingly, among small melanoma tumors of similar size, tumors derived from the MIC-1-transfected B16F1 cells exhibited enhanced blood vessel formation compared with those of mock transfectant cells. Also, more MIC-1 was found in well-vascularized tumor regions than in poorly vascularized tumor regions. Moreover, conditioned medium (CM) of the MIC-1-transfected melanoma cells enhanced the angiogenic properties of endothelial cells more than CM of mock transfectant cells. Notably, hypoxic culture conditions forced parental B16F1 cells to secrete more endothelial cell-stimulating factors, among which the function of MIC-1 was confirmed by blocking the effects with an anti-MIC-1 antibody. Taken together, these results suggest that the MIC-1 produced by melanoma cells in response to oxygen deprivation promotes tumor vascularization during melanoma development in vivo, leading to enhanced tumor growth and metastasis.

Abstract P211: The investigational chemoprotection drug ALRN-6924, a dual inhibitor of MDMX and MDM2, shows potential for radioprotection

Abstract Aim: We investigated whether p53 activation with ALRN-6924 can prevent toxicity in mouse models of acute radiation injury. Materials and methods: ALRN-6924 is a clinical-stage, first-in-class, stabilized cell-permeating alpha-helical peptide that disrupts the interaction of the p53 tumor suppressor protein with its endogenous inhibitors, MDMX and MDM2. In previous experiments it was shown that ALRN-6924 can induce transient, dose-dependent cell cycle arrest in the bone marrow to protect those cells from chemotherapy while not protecting p53-mutant cancer cells. Because radiation (like chemotherapy) preferentially affects proliferating cells, we hypothesized that ALRN-6924 may also protect proliferating cells in normal tissues from radiation-induced cellular toxicity. Cell cycle arrest was measured in the bone marrow of ALRN-6924-treated C57BL/6 mice by flow cytometry using EdU incorporation. Serum levels of macrophage inhibitory cytokine-1 (MIC-1), a biomarker of p53 activation, were measured by ELISA. Cell proliferation and apoptosis were measured in formalin-fixed mouse bone marrow by immunohistochemistry analysis of Ki67 and cleaved PARP, respectively. C57BL/6 mice (n=7/group) were treated with one or more intravenous 2.4 mg/kg doses of ALRN-6924 at 24, 16, 8, or 1 hour (or combinations thereof) or placebo prior to an abdominally targeted (shielded body) 15 Gy radiation dose and then monitored for body weight (BW). Results: MIC-1 was elevated in the serum of ALRN-6924-treated mice in a dose-dependent fashion. Repeated doses of ALRN-6924 every 8 hrs yielded sustained MIC-1 elevation, which correlated with reduced Ki67 positivity in the bone marrow. Treatment-dependent changes in cPARP expression were evident, but minimal in magnitude. In a nonlethal radiation exposure model, ALRN-6924 yielded significant protection from radiation-induced BW loss in a schedule-dependent manner. Placebo-treated mice showed 10% to 15% BW loss five days after irradiation, while mice receiving one or more ALRN-6924 doses 8 hrs prior to irradiation had an average of 4% BW loss (p=0.008, two-sided t test). Conclusions: ALRN-6924 mitigates toxicity in a mouse model of acute radiation injury. The observed radioprotection effect correlates with pharmacodynamic markers of cell proliferation and cell cycle arrest after one or more doses of ALRN-6924, and further supports previous demonstrations of chemoprotection with ALRN-6924. These results provide a rationale to investigate ALRN-6924 as a radioprotective agent. Citation Format: Allen Annis, David Sutton, Manuel Aivado, Vojislav Vukovic. The investigational chemoprotection drug ALRN-6924, a dual inhibitor of MDMX and MDM2, shows potential for radioprotection [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P211.