Pancreatic Cancer-induced Cachexia Research Articles

S100A8, S100A9 and S100A8/A9 heterodimer as novel cachexigenic factors for pancreatic cancer-induced cachexia

BackgroundCancer cachexia, occurring in ~ 80% pancreatic cancer (PC) patients overall, is a paraneoplastic syndrome mediated by cancer-induced systemic inflammation and characterized by weight loss and skeletal muscle wasting. Identifying clinically relevant PC-derived pro-inflammatory factors with cachexigenic potential may provide novel insights and therapeutic strategies.MethodsPro-inflammatory factors with cachexigenic potential in PC were identified by bioinformatic analysis. The abilities of selected candidate factors in inducing skeletal muscle atrophy were investigated. Expression levels of candidate factors in tumors and sera was compared between PC patients with and without cachexia. Associations between serum levels of the candidates and weight loss were assessed in PC patients.ResultsS100A8, S100A9, and S100A8/A9 were identified and shown to induce C2C12 myotube atrophy. Tumors of PC patients with cachexia had markedly elevated expression of S100A8 (P = 0.003) and S100A9 (P < 0.001). PC patients with cachexia had significantly higher serum levels of S100A8, S100A9 and S100A8/A9. Serum levels of these factors positively correlated with percentage of weight loss [correlation coefficient: S100A8: 0.33 (P < 0.001); S100A9: 0.30 (P < 0.001); S100A8/A9: 0.24 (P = 0.004)] and independently predicted the occurrence of cachexia [adjusted odds ratio (95% confidence interval) per 1ng/ml increase: S100A8 1.11 (1.02–1.21), P = 0.014; S100A9 1.10 (1.04–1.16), P = 0.001; per 1 µg/ml increase: S100A8/A9 1.04 (1.01–1.06), P = 0.009].ConclusionsAtrophic effects of S100A8, S100A9, and S100A8/A9 indicated them as potential pathogenic factors of PC-induced cachexia. In addition, the correlation with the degree of weight loss and prediction of cachexia in PC patients implicated their potential utility in the diagnosis of PC-induced cachexia.

Lipopolysaccharide-induced hypothalamic inflammation in cancer cachexia-anorexia is amplified by tumour-derived prostaglandin E2.

Cachexia-anorexia syndrome is a complex metabolic condition characterized by skeletal muscle wasting, reduced food intake and prominent involvement of systemic and central inflammation. Here, the gut barrier function was investigated in pancreatic cancer-induced cachexia mouse models by relating intestinal permeability to the degree of cachexia. We further investigated the involvement of the gut-brain axis and the crosstalk between tumour, gut and hypothalamus in vitro. Two distinct mouse models of pancreatic cancer cachexia (KPC and 4662) were used. Intestinal inflammation and permeability were assessed through fluorescein isothiocyanate dextran (FITC-dextran) and lipopolysaccharide (LPS), and hypothalamic and systemic inflammation through mRNA expression and plasma cytokines, respectively. To simulate the tumour-gut-brain crosstalk, hypothalamic (HypoE-N46) cells were incubated with cachexia-inducing tumour secretomes and LPS. A synthetic mimic of C26 secretome was produced based on its secreted inflammatory mediators. Each component of the mimic was systematically omitted to narrow down the key mediator(s) with an amplifying inflammation. To substantiate its contribution, cyclooxygenase-2 (COX-2) inhibitor was used. In vivo experiments showed FITC-dextran was enhanced in the KPC group (362.3 vs. sham 111.4ng/mL, P<0.001). LPS was increased to 140.9ng/mL in the KPC group, compared with sham and 4662 groups (115.8 and 115.8ng/mL, P<0.05). Hypothalamic inflammatory gene expression of Ccl2 was up-regulated in the KPC group (6.3 vs. sham 1, P<0.0001, 4662 1.3, P<0.001), which significantly correlated with LPS concentration (r=0.4948, P=0.0226). These data suggest that intestinal permeability is positively related to the cachexic degree. Prostaglandin E2 (PGE2) was confirmed to be present in the plasma and PGE2 concentration (log10) in the KPC group was much higher than in 4662 group (1.85 and 0.56ng/mL, P<0.001), indicating a role for PGE2 in pancreatic cancer-induced cachexia. Parallel to in vivo findings, in vitro experiments revealed that the cachexia-inducing tumour secretomes (C26, LLC, KPC and 4662) amplified LPS-induced hypothalamic IL-6 secretion (419%, 321%, 294%, 160%). COX-2 inhibitor to the tumour cells reduced PGE2 content (from 105 to 102 pg/mL) in the secretomes and eliminated the amplified hypothalamic IL-6 production. Moreover, results could be reproduced by addition of PGE2 alone, indicating that the increased hypothalamic inflammation is directly related to the PGE2 from tumour. PGE2 secreted by the tumour may play a role in amplifying the effects of bacteria-derived LPS on the inflammatory hypothalamic response. The cachexia-inducing potential of tumour mice models parallels the loss of intestinal barrier function. Tumour-derived PGE2 might play a key role in cancer-related cachexia-anorexia syndrome via tumour-gut-brain crosstalk.

Identification of circulating plasma ceramides as a potential sexually dimorphic biomarker of pancreatic cancer-induced cachexia.

Cancer patients who exhibit cachexia lose weight and have low treatment tolerance and poor outcomes compared to cancer patients without weight loss. Despite the clear increased risk for patients, diagnosing cachexia still often relies on self-reported weight loss. A reliable biomarker to identify patients with cancer cachexia would be a valuable tool to improve clinical decision making and identification of patients at risk of adverse outcomes. Targeted metabolomics, that included panels of amino acids, tricarboxylic acids, fatty acids, acylcarnitines, and sphingolipids, were conducted on plasma samples from patients with confirmed pancreatic ductal adenocarcinoma (PDAC) with and without cachexia and control patients without cancer (n=10/group, equally divided by sex). Additional patient samples were analyzed (total n=95) and Receiver Operating Characteristic (ROC) analyses were performed to establish if any metabolite could effectively serve as a biomarker of cachexia. Targeted profiling revealed that cachectic patients had decreased circulating levels of three sphingolipids compared to either non-cachectic PDAC patients or patients without cancer. The ratio of C18-ceramide to C24-ceramide (C18:C24) outperformed a number of other previously proposed biomarkers of cachexia (area under ROC = 0.810). It was notable that some biomarkers, including C18:C24, were only altered in cachectic males. Our findings identify C18:C24 as a potentially new biomarker of PDAC-induced cachexia that also highlight a previously unappreciated sexual dimorphism in cancer cachexia.

Caveolin‐1 increases glycolysis in pancreatic cancer cells and triggers cachectic states

In pancreatic cancer, autocrine insulin-like growth factor-1 (IGF-1) and paracrine insulin stimulate both IGF-1 receptor (IGF1R) and insulin receptor (IR) to increase tumor growth and glycolysis. In pancreatic cancer patients, cancer-induced glycolysis increases hepatic gluconeogenesis, skeletal muscle proteolysis, and fat lipolysis and, thereby, causes cancer cachexia. As a protein coexisting with IGF1R and IR, caveolin-1 (cav-1) may be involved in pancreatic cancer-induced cachexia. We undertook the present study to test this hypothesis. Out of wild-type MiaPaCa2 and AsPC1 human pancreatic cancer cell lines, we created their stable sub-lines whose cav-1 expression was diminished with RNA interference or increased with transgene expression. When these cells were studied in vitro, we found that cav-1 regulated IGF1R/IR expression and activation and also regulated cellular glycolysis. We transplanted the different types of MiaPaCa2 cells in growing athymic mice for 8 weeks, using intact athymic mice as tumor-free controls. We found that cav-1 levels in tumor grafts were correlated with expression levels of the enzymes that regulated hepatic gluconeogenesis, skeletal muscle proteolysis, and fat lipolysis in the respective tissues. When the tumors had original or increased cav-1, their carriers’ body weight gain was less than the tumor-free reference. When cav-1 was diminished in tumors, the tumor carriers’ body weight gain was not changed significantly, compared to the tumor-free reference. In conclusion, cav-1 in pancreatic cancer cells stimulated IGF1R/IR and glycolysis in the cancer cells and triggered cachectic states in the tumor carrier.

Pancreatic cancer induces muscle wasting by promoting the release of pancreatic adenocarcinoma upregulated factor

Cancer cachexia is a highly debilitating condition characterized by weight loss and muscle wasting that contributes significantly to the morbidity and mortality of pancreatic cancer. The factors that induce cachexia in pancreatic cancer are largely unknown. We previously showed that pancreatic adenocarcinoma upregulated factor (PAUF) secreted by pancreatic cancer cells is responsible for tumor growth and metastasis. Here, we analyzed the relation between pancreatic cancer-derived PAUF and cancer cachexia in mice and its clinical significance. Body weight loss and muscle weight loss were significantly higher in mice with Panc-1/PAUF tumors than in those with Panc-1/Mock tumors. Direct administration of rPAUF to muscle recapitulated tumor-induced atrophy, and a PAUF-neutralizing antibody abrogated tumor-induced muscle wasting in Panc-1/PAUF tumor-bearing mice. C2C12 myotubes treated with rPAUF exhibited rapid inactivation of Akt-Foxo3a signaling, resulting in Atrogin1/MAFbx upregulation, myosin heavy chain loss, and muscle atrophy. The neutrophil-to-lymphocyte ratio and body weight loss were significantly higher in pancreatic cancer patients with high PAUF expression than in those with low PAUF expression. Analysis of different pancreatic cancer datasets showed that PAUF expression was significantly higher in the pancreatic cancer group than in the nontumor group. Analysis of The Cancer Genome Atlas data found associations between high PAUF expression or a high DNA copy number and poor overall survival. Our data identified tumor-secreted circulating PAUF as a key factor of cachexia, causing muscle wasting in mice. Neutralizing PAUF may be a useful therapeutic strategy for the treatment of pancreatic cancer-induced cachexia.

Abstract IA-17: Mechanisms of pancreatic cancer-induced cachexia

Abstract Cachexia is a debilitating syndrome that results in severe, involuntary weight loss due to the depletion of skeletal muscle mass. Currently, no effective therapy exists to combat this malignant disorder. For pancreatic cancer, 85% of patients lose on average 14% of their pre-illness weight, and cachexia dramatically limits their ability to tolerate surgery, chemo- or radiotherapy. New therapies will likely evolve from an enhanced understanding of the mechanisms leading to muscle wasting and tumor development. Our laboratory has been examining the role of the NF-κB signaling pathway in tumorigenesis for several decades and that interest led us to discover the connection between NF-κB and muscle wasting in cancer cachexia and more recently in pancreatic cancer. We view the pathway as playing two separate functions in pancreatic cancer-induced cachexia. The first occurs at the level of skeletal muscle, or more preciously in skeletal muscle stem cells. We have found that during cancer progression, skeletal muscle undergoes a type of injury response leading to the activation of resident stem cells to engage in a regeneration program. NF-κB is activated in these stem cells and functions to inhibit regeneration, which contributes to the overall wasting process in cachexia. New data reveal that NF-κB activity in progenitor cells also regulates a local muscle inflammatory environment that might also contribute to skeletal muscle catabolism. The mechanism of this regulation will be discussed in more details. The second function of NF-κB signaling that we are pursuing focuses in the tumor microenvironment of pancreatic cancer. Using orthotopic mouse models of pancreatic cancer, we showed that NF-κB plays a critical role in protecting tumor cells from the surveillance property of anti-tumor macrophages. This occurs through the direct transcriptional regulation of the immunosuppressive cytokine, GDF15. Interestingly, circulating levels of GDF15 are elevated in cachectic patients and recent studies indicate that this cytokine might be an attractive therapeutic target in cancer cachexia. Together, we speculate that NF-κB functions in cancer cachexia by acting in muscle stem cells to block muscle repair, as well as promoting pancreatic cancer through the production of immunosuppressive genes such as GDF15. Citation Format: Benjamin Pryce, Nivedita Ratnam, Erin E. Talbert, Mary Dilhoff, Carl R. Schmidt, David J. Wang, Denis C. Guttridge. Mechanisms of pancreatic cancer-induced cachexia [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2020 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2020;80(22 Suppl):Abstract nr IA-17.

Resistance Training Impact on Mobility, Muscle Strength and Lean Mass in Pancreatic Cancer Cachexia: A Randomized Controlled Trial

Objective: To determine the efficacy of a three-month resistance training programme on the mobility, muscle strength and lean body mass of patients with pancreatic cancer-induced cachexia. Design: Randomized controlled trial. Setting: Elsahel Teaching Hospital, outpatient clinic of the Faculty of Physical Therapy, Cairo, Egypt. Participants: Patients with pancreatic cancer-induced cachexia. Interventions: Participants were randomized to the resistance training group (n = 20) and control group (n = 20). Main measures: Outcomes including mobility, muscle strength and lean body mass were measured at baseline, three months after surgical resection and 12 weeks after intervention. Results: The mean (SD) age was 51.9 (5.03) years and body mass index was 21.1 (1.13) kg/m²; 65% of patients were male. Compared to the control group, the resistance training group showed significant improvement in mobility: 400-m walk performance (270.3–256.9 seconds vs 266.4–264.2 seconds, respectively) and chair rise (13.82–12.53 seconds vs 13.77–13.46 seconds, respectively). Similarly, muscle strength was also significantly improved in the resistance training group than in the control group; we observed increase in peak torque of knee extensors (P = 0.004), elbow flexors (P = 0.001) and elbow extensors, improvement in lean mass of the upper limb (6.28–6.46 kg vs 6.31–6.23 kg, respectively) and lower limb (16.31–16.58 kg vs 16.4–16.31 kg, respectively). Conclusion: A three-month resistance training improved the mobility of patients with pancreatic cancer-induced cachexia. Muscle strength and lean body mass also improved.

SIRT1-NOX4 signaling axis regulates cancer cachexia.

Approximately one third of cancer patients die due to complexities related to cachexia. However, the mechanisms of cachexia and the potential therapeutic interventions remain poorly studied. We observed a significant positive correlation between SIRT1 expression and muscle fiber cross-sectional area in pancreatic cancer patients. Rescuing Sirt1 expression by exogenous expression or pharmacological agents reverted cancer cell-induced myotube wasting in culture conditions and mouse models. RNA-seq and follow-up analyses showed cancer cell-mediated SIRT1 loss induced NF-κB signaling in cachectic muscles that enhanced the expression of FOXO transcription factors and NADPH oxidase 4 (Nox4), a key regulator of reactive oxygen species production. Additionally, we observed a negative correlation between NOX4 expression and skeletal muscle fiber cross-sectional area in pancreatic cancer patients. Knocking out Nox4 in skeletal muscles or pharmacological blockade of Nox4 activity abrogated tumor-induced cachexia in mice. Thus, we conclude that targeting the Sirt1-Nox4 axis in muscles is an effective therapeutic intervention for mitigating pancreatic cancer-induced cachexia.

Nicotine Induces IL-8 Secretion from Pancreatic Cancer Stroma and Worsens Cancer-Induced Cachexia.

Smoking is highly associated with pancreatic cancer. Nicotine, the addictive component of tobacco, is involved in pancreatic cancer tumorigenesis, metastasis, and chemoresistance. This work aimed to describe the role of nicotine within the pancreatic cancer tumor microenvironment. Nicotine treatment was used in vitro to assess its effect on tumor-associated stromal cells and pancreatic cancer cells. Nicotine treatment was then used in a pancreatic cancer patient-derived xenograft model to study the effects in vivo. Nicotine induced secretion of interleukin 8 (IL-8) by tumor-associated stroma cells in an extracellular signal-regulated kinase (ERK)-dependent fashion. The secreted IL-8 and nicotine acted on the pancreatic cancer cell, resulting in upregulation of IL-8 receptor. Nicotine treatment of mice bearing pancreatic cancer patient-derived xenografts had significantly increased tumor mass, increased tumor-free weight loss, and decreased muscle mass. These represent important pathways through which nicotine acts within the tumor microenvironment and worsens pancreatic cancer-induced cachexia, potentially representing future therapeutic targets.

Molecular and Physiological Evaluation of Pancreatic Cancer-Induced Cachexia.

Cachexia, a complex metabolic syndrome, is characterized by involuntary weight loss along with muscle wasting and fat depletion leading to poor quality of life of patients. About 80% ofpancreatic cancer patients exhibit cachectic phenotype at the time of diagnosis. Here, we present the several molecular and physiological parameters, which we utilize to study the pancreatic cancer-induced cachexia in in vitro models and preclinical mice models of pancreatic cancer. We have described myotube and adipocyte-based in vitro models of muscle and fat wasting, including methods of cell culture, differentiation, and treatment with cancer cell-conditioned medium. Furthermore, we have explained the methods of evaluation of key cachectic markers for muscles. Next, we have detailed the orthotopic implantation mouse models of pancreatic cancer and evaluation of different physiological parameters, including body weight, food intake, body composition analysis, glucose tolerance test, insulin resistance test, grip strength measurement, and rotarod performance test. We have also explained morphological parameters and molecular markers to evaluate the muscle wasting in pancreatic cancer-induced cachexia.

Abstract 4090: Generation of a new mouse to model pancreatic cancer-induced cachexia

Abstract Of all cancers, pancreatic cancer causes the third most fatalities, and incidence rates of this devastating disease continue to rise. Further, pancreatic cancer presents with the highest incidence of cachexia, a syndrome of weight loss due to depletion of skeletal muscle and adipose tissue. Clinically, cachexia is associated with increased mortality, poor quality of life, poor treatment responses, and increased treatment complications. Although clearly the best way to prevent cachexia is to address the cancer, pancreatic cancer has proven challenging to treat, with a dismal 9% 5-year survival rate. We believe effective anti-cachexia therapy will improve the care of pancreatic cancer patients, but the development of these therapies will require animal models that accurately recapitulate the etiology of pancreatic cancer-induced cachexia. To improve on the current, non-pancreas tumor xenograft models of cachexia, we generated a genetically engineered mouse model (GEMM) of pancreatic cancer, where induction of Kras and loss of the tumor suppressor Pten occurs in the pancreas of postnatal mice, which we refer to as the KPP model. KPP mice progressively lose skeletal muscle and adipose mass as a result of their cancer. We find that KPP mice exhibit histologic features of pancreatic ductal adenocarcinoma and reach endpoint criteria at an average of 107 days of age. Beginning at approximately 75 days of age, KPP mice undergo progressive loss of existing skeletal muscle mass, resulting in decreased muscle function. We also find that muscle loss from KPP mice exhibits a gene expression signature that closely aligns with the gene expression signature in muscle from cachectic pancreatic cancer patients. In summary, we expect KPP mice to serve as a useful model to elucidate the underlying mechanisms of muscle loss in pancreatic cancer-induced cachexia and to evaluate potential anti-cachexia therapies. Citation Format: Erin E. Talbert, Katherine J. Ladner, Maria Cecilia Cuitino, Gustavo W. Leone, Denis C. Guttridge. Generation of a new mouse to model pancreatic cancer-induced cachexia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4090.

The Warburg effect in human pancreatic cancer cells triggers cachexia in athymic mice carrying the cancer cells

BackgroundCancer cachexia is a cancer-induced metabolic disorder and a major cause of cancer-induced death. The constituents of cancer cachexia include an increase in energy expenditure, hepatic gluconeogenesis, fat lipolysis, and skeletal-muscle proteolysis and a decrease in body weight. The aetiology of cancer cachexia is unclear and may involve cancer-cell metabolism and secretion. In this study, we investigated whether the high glycolysis in cancer cells (the Warburg effect) triggers cachexia in athymic mice carrying pancreatic cancer cells.MethodsFirst, we examined five human pancreatic cancer cell lines for glycolysis and cachectic-cytokine secretion. Consequently, MiaPaCa2 and AsPC1 cells were selected for the present study, because the glycolysis in MiaPaCa2 cells was typically high and that in AsPC1 cells was exceptionally low. In addition, both MiaPaCa2 and AsPC1 cells were competent in the secretion of examined cytokines. Next, we transplanted MiaPaCa2 and AsPC1 cells subcutaneously in different athymic mice for 8 weeks, using intact athymic mice for control. In another experiment, we treated normal mice with the supernatants of MiaPaCa2 or AsPC1 cells for 7 days, using vehicle-treated mice for control. In both models, we measured food intake and body weight, assayed plasma glucose, triglycerides, and TNF-α and used Western blot to determine the proteins that regulated hepatic gluconeogenesis, fat lipolysis, and skeletal-muscle proteolysis in the corresponding tissues. We also studied the effect of MiaPaCa2-cell supernatants on the proteolysis of C2C12 skeletal-muscle cells in vitro.ResultsThe athymic mice carrying high-glycolytic MiaPaCa2 cells had anorexia and also showed evidence for cachexia, including increased hepatic gluconeogenesis, fat lipolysis and skeletal-muscle proteolysis and decreased body weight. The athymic mice carrying low-glycolytic AsPC1 cells had anorexia but did not show the above-mentioned evidence for cachexia. When normal mice were treated with the supernatants of MiaPaCa2 or AsPC1 cells, their energy homeostasis was largely normal. Thus, the cachexia in the athymic mice carrying MiaPaCa2 cells may not result from humeral factors released by the cancer cells. In vitro, MiaPaCa2-cell supernatants did not induce proteolysis in C2C12 cells.ConclusionThe Warburg effect in pancreatic cancer cells is an independent aetiological factor for pancreatic cancer-induced cachexia.

Abstract LB-267: Metabolic alterations in tumors cause cachexia in pancreatic cancer

Abstract Cancer-associated cachexia is a complex metabolic syndrome which leads to excessive loss of skeletal muscle and adipose deposits. Up to 80% of pancreatic cancer patients suffer from cachexia and nearly one third die due to complexities related to the syndrome. Treatment of cachexia will not only improve the standard of living of pancreatic cancer patients but would also improve the patient survival. In the clinic, the majority of cancer patients are diagnosed at the refractory phase of cachexia, which cannot be reversed by dietary interventions. Till late, cachexia has mainly been attributed to systemic inflammation caused by cytokines released from the host and the tumor. But anti-inflammatory therapies have not shown promising results in clinical trials. Hence, there is an urgent need to identify new targets to combat cancer cachexia. It has been previously shown that there are constant metabolic interactions between the host body and the tumor. Increase in tumor burden and its demand for nutrition forces the host body to reprogram its metabolism leading to the breakdown of host body proteins into amino acids, which gets taken up and converted into carbohydrates by the tumor. To study the role of metabolic pathways in tumor cells on cachectic factor secretion, we pre-treated pancreatic cancer cells with metabolic inhibitors 3-Bromopyruvic acid and bis-2-(5-phenylacetomido-1, 2, 4-thiadiazol-2-yl) ethyl sulfide (BPTES). The conditioned media from control and treated cells were then evaluated for myotube degeneration potential in C2C12-dfferentitaed myotubes by measuring myotube thickness, protein content and expression of muscle specific ubiquitin ligases. We observed that that pre-treated conditioned-media had reduced myotubes degenerating potential as compared to controls. Furthermore, we inhibition of glycolytic flux in tumor cells by treatment with ketone bodies also diminished myotubes degenerating potential. Tumor-bearing mice had decreased tumor growth and cachexia when fed on a ketogenic diet. In conclusion, metabolic reprograming of tumor cells plays an important role in inducing pancreatic cancer-induced cachexia and delineating the metabolic pathways is crucial to elucidate important therapeutic targets for cancer cachexia. Citation Format: Aneesha Dasgupta, Surendra K. Shukla, Venugopal Gunda, Nina V. Chaika, Pankaj K. Singh. Metabolic alterations in tumors cause cachexia in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-267. doi:10.1158/1538-7445.AM2017-LB-267

Detection of Pancreatic Cancer-Induced Cachexia Using a Fluorescent Myoblast Reporter System and Analysis of Metabolite Abundance.

The dire effects of cancer-induced cachexia undermine treatment and contribute to decreased survival rates. Therapeutic options for this syndrome are limited, and therefore efforts to identify signs of precachexia in cancer patients are necessary for early intervention. The applications of molecular and functional imaging that would enable a whole-body "holistic" approach to this problem may lead to new insights and advances for diagnosis and treatment of this syndrome. Here we have developed a myoblast optical reporter system with the purpose of identifying early cachectic events. We generated a myoblast cell line expressing a dual tdTomato:GFP construct that was grafted onto the muscle of mice-bearing human pancreatic cancer xenografts to provide noninvasive live imaging of events associated with cancer-induced cachexia (i.e., weight loss). Real-time optical imaging detected a strong tdTomato fluorescent signal from skeletal muscle grafts in mice with weight losses of only 1.2% to 2.7% and tumor burdens of only approximately 79 to 170 mm(3). Weight loss in cachectic animals was also associated with a depletion of lipid, cholesterol, valine, and alanine levels, which may provide informative biomarkers of cachexia. Taken together, our findings demonstrate the utility of a reporter system that is capable of tracking tumor-induced weight loss, an early marker of cachexia. Future studies incorporating resected tissue from human pancreatic ductal adenocarcinoma into a reporter-carrying mouse may be able to provide a risk assessment of cachexia, with possible implications for therapeutic development.

Silibinin-mediated metabolic reprogramming attenuates pancreatic cancer-induced cachexia and tumor growth

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the US. Cancer-associated cachexia is present in up to 80% of PDAC patients and is associated with aggressive disease and poor prognosis. In the present studies we evaluated an anti-cancer natural product silibinin for its effectiveness in targeting pancreatic cancer aggressiveness and the cachectic properties of pancreatic cancer cells and tumors. Our results demonstrate that silibinin inhibits pancreatic cancer cell growth in a dose-dependent manner and reduces glycolytic activity of cancer cells. Our LC-MS/MS based metabolomics data demonstrates that silibinin treatment induces global metabolic reprogramming in pancreatic cancer cells. Silibinin treatment diminishes c-MYC expression, a key regulator of cancer metabolism. Furthermore, we observed reduced STAT3 signaling in silibinin-treated cancer cells. Overexpression of constitutively active STAT3 was sufficient to substantially revert the silibinin-induced downregulation of c-MYC and the metabolic phenotype. Our in vivo investigations demonstrate that silibinin reduces tumor growth and proliferation in an orthotopic mouse model of pancreatic cancer and prevents the loss of body weight and muscle. It also improves physical activity including grip strength and latency to fall in tumor-bearing mice. In conclusion, silibinin-induced metabolic reprogramming diminishes cell growth and cachectic properties of pancreatic cancer cells and animal models.

Abstract 1886: Metabolic alterations associated with pancreatic cancer-induced cachexia.

Abstract Cachexia, a metabolic syndrome, leads to loss of muscle weight and fat tissues. Cancer-induced cachexia accounts for nearly 20% of all cancer-related deaths and is most prevalent in patients with gastric, pancreatic, colon and lung cancer. Although association of cachexia with various types of cancers has been known for a long time, the molecular mechanism of cancer-induced cachexia is still not well understood. Better understanding of the cancer-related cachexia syndrome may provide novel therapeutic targets and improved health care for cancer patients. By culturing differentiated C2C12 and 3T3-L1 cells in the presence of pancreatic adenocarcinoma cell or immortalized epithelial cell supernatants, we established cell culture-based cachexia model systems to investigate the depletion of muscle mass and fatty acid storage. Progressive physiological and biochemical alterations during muscle fibre breakdown and adipocyte fat depletion were assayed by utilizing western blotting, real-time PCR and cell imaging. We then investigated metabolomic alterations in C2C12 and 3T3-L1 cell lines in response to the cachectic factors secreted by the tumor cells. We performed differential metabolomic analyses on tumor cell supernatant-treated or control treated differentiated C2C12 muscle fibers and 3T3-L1-derived adipocytes by utilizing 2D 1H-13C HSQC NMR technique. Alterations in metabolic pathways were also investigated by evaluating the expression of metabolic genes in the corresponding pathways by performing quantitative real-time PCR. To obtain further insights into the metabolic alterations that trigger cachexia, we extended our studies to in vivo mouse orthotopic xenograft models and investigated alterations in metabolic gene expression and metabolite flux in muscle and fat tissues of tumor-bearing mice. Our results identify crucial nodes in metabolite flux that can be targeted to regulate cell growth, proliferation, and turnover in muscle and fat tissues during cancer-induced cachexia. Citation Format: Surendra K. Shukla, Pankaj K. Singh. Metabolic alterations associated with pancreatic cancer-induced cachexia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1886. doi:10.1158/1538-7445.AM2013-1886

Abstract 2670: Metabolomic and molecular insights into pancreatic cancer-induced cachexia.

Abstract Pancreatic cancer is an aggressive and lethal neoplasm that induces cachexia and is typically detected at an advanced stage. Better understanding of the disease, early detection, and new therapeutic targets are urgently needed. Here we have investigated the metabolism of multiple pancreatic tumors, and their effect on mouse body weight. To understand the interactions between the tumor and normal tissue, we are developing a cell-based optical biosensor using genetically engineered myoblasts to detect the early onset of cachexia-inducing signals in muscle tissue. We have also characterized the expression of choline kinase (Chk), which is known to be overexpressed in aggressive cancer, and cyclooxygenase 2 (COX-2), a critically important inflammation mediator that significantly influences cancer angiogenesis, invasion, and metastasis. Human pancreatic adenocarcinoma cell lines Pa02C and Pa04C (Jones et al, Science 2008), as well as Panc1, and BxPC3 (obtained from ATCC), were inoculated subcutaneously in male SCID mice. Mouse bodyweight was followed for approximately 6 weeks. Tumors (500 mm3) were excised and freeze-clamped for immunoblot and high-resolution 1H MRS analyses. A loss of body weight was observed after inoculation of Pa04C and Panc1 cells but not BxPc3 and Pa02C cells. Panc1 tumors exhibited high expression levels of COX-2 and the highest levels of Chk. However, Pa04C tumors showed low levels of those two proteins. 1H MRS analysis revealed that Panc1 tumors contained the highest level of total choline, mainly due to a high level of phosphocholine, correlating with the high level of Chk. Panc1 tumors were also characterized by a high level of lactate. Pa04C tumors presented with the second highest levels of total choline and lactate. To determine the effect of pancreatic cancer cells on muscle, we transiently co-transfected primary human myoblasts with constitutive EF-1α driven eGFP expression and with either a control vector, triple-tandem repeat of a NFκB cis-element lacking a minimal promoter (mp) sequence, or with the same tandem repeat fused to a minimal promoter sequence (3xNFκB-mp) driving tdTomato expression. The transfected myoblasts were differentiated into myotubes and then treated for 24 h with conditioned medium from pancreatic tumor cells. We observed that the 3xNFκB-mp promoter was inducible in the presence of conditioned medium obtained from both Panc1 and Pa04C cells. No red fluorescence was induced in undifferentiated myoblasts or in confluent myoblasts. The acquisition of in vivo 1H MRSI is ongoing, and should further improve the characterization of those pancreatic cell lines, and the correlation between the metabolites measured in vivo and weight loss. Our data identify increased total choline and lactate as potential imaging biomarkers to detect pancreatic cancer, and Chk and COX-2 as potential therapeutic targets of this devastating disease. This work was supported by NIH P50CA103175. Citation Format: Marie-France Penet, Paul T. Winnard, Flonné Wildes, Yelena Mironchik, Tariq Shah, Anirban Maitra, Zaver M. Bhujwalla. Metabolomic and molecular insights into pancreatic cancer-induced cachexia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2670. doi:10.1158/1538-7445.AM2013-2670