Proteomic Serum Biomarkers and Their Potential Application in Cancer Screening Programs

Early diagnosis of cancer is of pivotal importance to reduce disease-related mortality. There is great need for non-invasive screening methods, yet current screening protocols have limited sensitivity and specificity. The use of serum biomarkers to discriminate cancer patients from healthy persons might be a tool to improve screening programs. Mass spectrometry based proteomics is widely applied as a technology for mapping and identifying peptides and proteins in body fluids. One commonly used approach in proteomics is peptide and protein profiling. Here, we present an overview of profiling methods that have the potential for implementation in a clinical setting and in national screening programs

Characteristics of Upper Limb Impairment Related to Degenerative Cervical Myelopathy: Development of a Sensitive Hand Assessment (Graded Redefined Assessment of Strength, Sensibility, and Prehension Version Myelopathy)

BACKGROUND Degenerative cervical myelopathy (DCM) involves spinal cord compression, which causes neurological decline. Neurological impairment in DCM is variable and can involve complex upper limb dysfunction including loss of manual dexterity, hyperreflexia, focal weakness, and sensory impairment. The modified Japanese Orthopaedic Association (mJOA) score relies on the patients' subjective perceptions, whereas existing objective measures such as strength and sensory testing do not capture subtle changes in dexterity and function. OBJECTIVE 1) To characterize arm and hand function in DCM; and 2) To develop and validate Graded Redefined Assessment of Strength, Sensibility, and Prehension Version-Myelopathy (GRASSP-M), a clinical assessment that quantifies upper limb impairment. METHODS A total of 148 DCM patients (categorized into mild, moderate, and severe based on mJOA grade) and 21 healthy subjects were enrolled. A complete neurological exam, the mJOA, the QuickDASH, grip dynamometry, and the GRASSP-M were administered. RESULTS Strength, sensation, and manual dexterity significantly declined with increasing DCM severity (P ≤ .05). Impairment in hand dexterity showed better discrimination between mild, moderate, and severe DCM categories than strength or sensation. The GRASSP-M was found to be both a reliable (intraclass correlation coefficient >0.75 for intra- and inter-rater reliability) and valid (with both concurrent and construct validity) tool. CONCLUSION These results demonstrate that patients' subjective reporting of functional status, especially in the mild DCM category, may underrepresent the extent of functional impairment. The GRASSP-M is an objective tool designed to characterize patients' functional impairment related to the upper limb, which proves useful to diagnose and quantify mild dysfunction, monitor patients for deterioration, and help determine when patients should be treated surgically

Ultrahigh resolution profiles lead to more detailed serum peptidome signatures of pancreatic cancer

Mass spectrometry-based (clinical) proteomics has been widely applied as a technology to find and validate disease-specific protein signatures. MALDI-based peptidome profiles provide a suitable platform for classification of body fluids or tissues, albeit at the cost of being unable to observe low abundant species. Here we show that a fully automated one-step solid-phase extraction serum sample cleanup in combination with fast MALDI acquisition and ultrahigh precision 15 T FTICR readout provides a powerful, fast and robust approach for obtaining biomarker signatures. This is exemplified for a cohort of pancreatic cancer patients. Specific “early cancer” symptoms such as pain, jaundice or weight loss are often not experienced, thus delaying diagnosis of the disease. Novel markers for early diagnosis of pancreatic cancer are therefore urgently needed. A total of 273 serum samples, distributed over a calibration and validation set, were processed and mass analyzed within a time frame of 24 h. In both sets sensitivity and selectivity values were well above 85%. In these “next-generation” MALDI peptidome profiles all species up to 9 kDa were isotopically resolved. Finally, it is noted that the low ppm mass accuracy of peptides and proteins observed between 1 and 9 kDa in the FTICR profiles facilitates sequence identifications

Serum peptide signatures for pancreatic cancer based on mass spectrometry : a comparison to CA19-9 levels and routine imaging techniques

Purpose The detection of pancreatic tumors lacks a sensitive and specific diagnostic tool. Mass spectrometry (MS)based profiling of serum proteins is a promising approach for discovery of new clinical biomarkers or biomarker signatures. Methods Serum samples from pancreatic cancer (PC) patients and control individuals were collected and processed using a standardized protocol. Samples were divided in a calibration set (n = 49 PC and 110 controls) and a validation set (n = 39 PC and 75 controls). Peptide profiles were obtained using a combination of automated solid-phase extraction with reversed-phase C18 paramagnetic beads and matrix-assisted laser desorption ionization time-of-flight MS. Results Linear discriminant analysis with double cross-validation resulted in a discriminating peptide signature for PC in the calibration set with a sensitivity of 78 % and a specificity of 91 % [ area under the curve (AUC) of 92 %]. Classification was validated with a sensitivity of 93 % and a specificity of 100 % (AUC of 98 %), and the results were compared with carbohydrate antigen 19-9 levels and currently available clinical imaging techniques. The ten most discriminating peptide peaks were identified as fragments of proteins involved in the clotting cascade, acute phase response and immunologic response. Conclusions In this study, it is shown that MS-based serum peptide profiles can discriminate between PC and control samples. The approach has great potential for highthroughput analysis in surveillance programs and appears to be most promising for patients with an inherited risk for PC, who benefit from more frequent screening

Serum peptide signatures for pancreatic cancer based on mass spectrometry : a comparison to CA19-9 levels and routine imaging techniques

Purpose The detection of pancreatic tumors lacks a sensitive and specific diagnostic tool. Mass spectrometry (MS)based profiling of serum proteins is a promising approach for discovery of new clinical biomarkers or biomarker signatures. Methods Serum samples from pancreatic cancer (PC) patients and control individuals were collected and processed using a standardized protocol. Samples were divided in a calibration set (n = 49 PC and 110 controls) and a validation set (n = 39 PC and 75 controls). Peptide profiles were obtained using a combination of automated solid-phase extraction with reversed-phase C18 paramagnetic beads and matrix-assisted laser desorption ionization time-of-flight MS. Results Linear discriminant analysis with double cross-validation resulted in a discriminating peptide signature for PC in the calibration set with a sensitivity of 78 % and a specificity of 91 % [ area under the curve (AUC) of 92 %]. Classification was validated with a sensitivity of 93 % and a specificity of 100 % (AUC of 98 %), and the results were compared with carbohydrate antigen 19-9 levels and currently available clinical imaging techniques. The ten most discriminating peptide peaks were identified as fragments of proteins involved in the clotting cascade, acute phase response and immunologic response. Conclusions In this study, it is shown that MS-based serum peptide profiles can discriminate between PC and control samples. The approach has great potential for highthroughput analysis in surveillance programs and appears to be most promising for patients with an inherited risk for PC, who benefit from more frequent screening