Identification of Predictive Biomarkers for Response to Trastuzumab Using Plasma FUCA Activity and N-Glycan Identified by MALDI-TOF-MS

Abstract

The aim of this study was to identify glycobiological biomarkers that indicate sensitivity to trastuzumab, a humanized monoclonal antibody against HER2 in plasma samples from breast cancer patients. Plasma samples were obtained from 24 breast cancer patients treated with trastuzumab monotherapy. The catalytic activities of plasma alpha1-6, fucosyltransferase (FUT8) and alpha-L fucosidase (FUCA) were analyzed using high-performance liquid chromatography (HPLC) and spectrophotometer, respectively. The plasma N-glycan profiles were investigated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Plasma FUT8 activity was not significantly correlated with either the clinical response or progression-free survival (PFS). On the other hand, plasma FUCA activity was significantly correlated with PFS (p < 0.05). The MALDI-TOF-MS analysis of the plasma N-glycan profile revealed that the expression of 2534 m/z N-glycan was lower in patients with progressive disease (PD) and was correlated with PFS. Low expression of 2534 m/z N-glycan discriminated between PD and non-PD with 75% sensitivity and 82% specificity. We demonstrated that the plasma FUCA activity and 2534 m/z N-glycan may be predictive biomarkers of sensitivity to trastuzumab. Our results suggest that glycosylation analysis may provide useful information for determining clinical cancer therapy and provide novel insight into biomarker studies using glycobiological tools in the field of breast cancer.

Mass spectrometry of peptides and proteins from human blood

“…Mass spectrometry is now being applied to the discovery of polypeptides of blood associated with disease Karamessinis et al, 2008;Lee et al, 2008). Direct mass spectrometric measurements, or proteins discovered via mass spectrometry, will also yield biomarkers (Luisetti et al, 2008;Matsumoto et al, 2009). Given the challenges associated with the direct examination of blood fluids there have been attempts to model cancer and other cells in culture byexamining the secreted proteins, where the media represents the circulating blood.…”

“…Serum can be generated from blood drawn into glass or plastic tubes and permitted to coagulate prior to centrifugal collection. Plasma may be collected on ice with the use of citrate, heparin, or EDTA that may inhibit the FeS proteases, followed by centrifugation at 48C (Tammen et al, 2005a,b;Albrethsen et al, 2006a;Kim et al, 2007;Tammen, 2008;Matsumoto et al, 2009). Hence serum is whole blood where the cells were removed by the formation of a clot that consumes and insolublizes participants in the coagulation cascade.…”

“…Somatropin was measured using the bovine protein as an internal standard followed by solid phase extraction and a triple-quadruple mass spectrometer . The increased activity of plasma alpha-L fucosidase and concomitant reduction in a 2534 m/z N-glycan may be predictive biomarkers of sensitivity to the humanized monoclonal antibody trastuzumab (Matsumoto et al, 2009). Hepcidin is a polypeptide that regulates iron metabolism, binds alpha2-macroglobulin (Peslova et al, 2009) and may have therapeutic or diagnostic potential for conditions such as renal cell carcinoma (Kamai et al, 2009).…”

“…In addition, proteins may be released from cells within exosomes (Looze et al, 2009). Specific proteins, enzyme activities, or modifications of the structure of blood proteins may serve as biomarkers of disease, environmental factors, therapeutic efficacy or host response (Teodoro et al, 2006;Taguchi et al, 2007;de Roos et al, 2008;Matsumoto et al, 2009). Presently, the majority of proteins in the blood are measured by ELISA assays (Heidema et al, 2009) or by enzyme activity but mass spectrometry has the potential to replace these assays in some cases.…”

Recent Advances in MALDI-MS Based Quantitative Targeted Glycan Analysis

“…재조합 당단백질 의약품의 당쇄 구조가 오리지널 바이오 의약품이 갖는 당쇄와 정성 및 정량적으로 다를 경우, 투약 후 인체 내에서의 생리 활성이 크게 달라질 수 있으며 길항 작용을 하는 등 여러 생리학적인 문제를 야기 할 수 있다 [3]. (Table 1) [13,23,24]. 본 총설에서는 MALDI-MS 기반의 효과적인 당쇄 정량 분석 방법과 재조합 단백질 의약품의 당 쇄 분석 활용 예시, 그리고 질병 진단을 위한 임상시료의 초 고속 대용량 (high-throughput) 당쇄 분석 시스템에 대해 기술 하고자 한다 (Table 2).…”