Distinct serum metabolomics profiles associated with malignant progression in the KrasG12Dmouse model of pancreatic ductal adenocarcinoma

Abstract

BackgroundPancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer deaths worldwide with less than a 6% 5-year survival rate. PDAC is associated with poor prognosis based on the late stage diagnosis of the disease. Current diagnostic tests lack the sensitivity and specificity to identify markers of early staging. Metabolomics has provided biomarkers for various diseases, stressors, and environmental exposures. In this study we utilized the p48-Cre/LSL-KrasG12D mouse model with age-matched wild type mice. This model shows malignant progression to PDAC analogous to the human disease stages via early and late pancreatic intra-epithelial neoplasia (PanIN) lesions.ResultsSerum was collected from mice with early PanIN lesions (at 3-5 months) and with late PanIN or invasive PDAC lesions (13-16 months), as determined by histopathology. Metabolomics analysis of the serum samples was conducted through UPLC-TOFMS (Ultra Performance Liquid Chromatography coupled to Time-of-flight Mass Spectrometry). Multivariate data analysis revealed distinct metabolic patterns in serum samples collected during malignant progression towards invasive PDAC. Animals with early or late stage lesions were distinguished from their respective controls with 82.1% and 81.5% accuracy, respectively. This also held up for randomly selected subgroups in the late stage lesion group that showed less variability between animals. One of the metabolites, citrate, was validated through tandem mass spectrometry and showed increased levels in serum with disease progression. Furthermore, serum metabolite signatures from animals with early stage lesions identified controls and animals with late stage lesions with 81.5% accuracy (p<0.01) and vice-versa with 73.2% accuracy (p<0.01).ConclusionsWe conclude that metabolomics analysis of serum samples can identify the presence of early and late stage pancreatic cancer.

A Metabolomic and Lipidomic Serum Signature from Nonhuman Primates Administered with a Promising Radiation Countermeasure, Gamma-Tocotrienol

“…Serum was prepared for metabolomic analysis as described previously [ 34 , 35 ]. Briefly, metabolite extraction was performed by adding 75 μL of 40% isopropanol (IPA) + 25% methanol + 35% water containing internal standards to 25 μL of NHP plasma.…”

Early detection of pancreatic cancer: Where are we now and where are we going?

“…Kynurenate and methionine levels were upregulated in PanIN but downregulated in PC, and could be used as biomarkers to distinguish PanIN from PC . LaConti et al . used the p48‐Cre/LSL‐Kras G12D mouse model to evaluate the early diagnostic value of serum metabolomics in PC.…”

Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling

“…Harvesting of the mouse pancreas by dissection allows for multiple types of analysis to be conducted on the same sample. The most popular of these include, but are not limited to, fluorescence microscopy, hematoxylin and eosin histology, immunohistochemistry, mass spectrometry, and nuclear magnetic resonance spectroscopy 6,7,14,15 . Diseases like diabetes, pancreatitis, and pancreatic cancer can be studied using the techniques mentioned above 16 .…”

“…. Harvesting the pancreas at ages ranging from five to fifteen months can also be used to prepare tissue extracts to characterize global changes in pancreas 4 metabolism that occur during the transition from healthy to diseased tissue 6,7 . This article presents a complete visual guide of the steps required to perform a mouse pancreas extraction and provides guidelines for storage of a pancreas for further analysis.…”