N1,N12-Diacetylspermine as a Blood Based Lung Cancer Biomarker

Abstract

It is becoming well recognized that metabolic perturbations are inherent hallmarks of tumorigenesis [1,2]. Metabolites represent the functional products of cellular processes, which are highly responsive to both pathological and environmental stimuli. As such, metabolites are the closest representation of an individual's current physiological state. Therefore, exploration of metabolic alterations in the context of disease pathophysiology, most notably cancer, holds great promise and considerable clinical value. This field of research has benefited from technological advances in mass spectrometry and ultraviolet-visible spectroscopic analyses that have enabled comprehensive metabolomic analyses of diverse arrays of metabolites, polyphenols and lipids in a variety of biological matrices with substantial robustness and sensitivity [3][4][5][6][7][8][9]. As a result, interest in the application of metabolomics to identify key metabolic differences related to pathological conditions has expanded. Indeed, metabolomics has been explored to gain insights into the pathophysiology of cancer, develop methods predictive of disease onset, and reveal new biomarkers relevant to disease diagnosis and prognosis [4-6] [10-12].The application of metabolomics to the discovery of blood-based biomarker in cancer has substantial potential clinical relevance. Recently, we have identified the polyamine end-product N1, N12-diacetylspermine (DAS) as a novel pre-diagnostic serum biomarker for non-small cell lung cancer (NSCLC) [6]. In this study, DAS alone yielded an AUC of 0.610 and AUC 0.710 for sera collected 6 to 12 months and 0 to 6 months before onset of symptoms and diagnosis, respectively, in the discovery set. These findings were subsequently confirmed in an independent and blinded validation set [6]. Single markers are unlikely to exhibit sufficient performance to be fully informative of disease status. Therefore in our study we examined the performance of DAS in combination with another marker Pro-SFTPB, which we previously validated as a blood based marker for NSCLC [13]. The combination of DAS and Pro-SFTPB resulted in improved performance compared to either alone (Overall AUCs of 0.732, 0.650 and 0.699 in the validation set for Pro-SFTPB + DAS, DAS only and Pro-SFTPB only, respectively) [6]. This study highlights the potential contributions of metabolomics to the discovery of biomarkers that inform about disease risk before the onset of symptoms and, importantly, illustrates the value of DAS as a complementary non-invasive biomarker. While the latter findings implicate that DAS is not specific to lung cancer, it does highlight conserved metabolic dysregulation of polyamine biosynthesis, which is strongly associated with tumorigenesis [15,16]. However, one caveat that must always be considered is whether serum or urinary DAS differs between malignant and benign tumors. This is particularly relevant in lung cancer as screening methodologies have been largely hindered by high false positive rates, a consequence of the low preval...

Rapid LC-MS/MS quantification of cancer related acetylated polyamines in human biofluids

“…Specifically, N 1 ,N 12 -diacetylspermine (DAS), N 1 -acetylspermine (ASP), and N 8acetylspermidine (ASD) have been found to be elevated in urine of patients with a wide range of cancer types [2][3][4][5][6][7][8]. In recent years APs have been found to be elevated in matrices other than urine [9]. For instance, DAS was found to be increased in blood serum of patients 6-12 months prior to lung cancer diagnosis [10].…”