Differential profiling of breast cancer plasma proteome by isotope-coded affinity tagging method reveals biotinidase as a breast cancer biomarker

<p>Abstract</p> <p>Background</p> <p>Breast cancer is one of the leading causes of women's death worldwide. It is important to discover a reliable biomarker for the detection of breast cancer. Plasma is the most ideal source for cancer biomarker discovery since many cells cross-communicate through the secretion of soluble proteins into blood.</p> <p>Methods</p> <p>Plasma proteomes obtained from 6 breast cancer patients and 6 normal healthy women were analyzed by using the isotope-coded affinity tag (ICAT) labeling approach and tandem mass spectrometry. All the plasma samples used were depleted of highly abundant 6 plasma proteins by immune-affinity column chromatography before ICAT labeling. Several proteins showing differential abundance level were selected based on literature searches and their specificity to the commercially available antibodies, and then verified by immunoblot assays.</p> <p>Results</p> <p>A total of 155 proteins were identified and quantified by ICAT method. Among them, 33 proteins showed abundance changes by more than 1.5-fold between the plasmas of breast cancer patients and healthy women. We chose 5 proteins for the follow-up confirmation in the individual plasma samples using immunoblot assay. Four proteins, α1-acid glycoprotein 2, monocyte differentiation antigen CD14, biotinidase (BTD), and glutathione peroxidase 3, showed similar abundance ratio to ICAT result. Using a blind set of plasmas obtained from 21 breast cancer patients and 21 normal healthy controls, we confirmed that BTD was significantly down-regulated in breast cancer plasma (Wilcoxon rank-sum test, <it>p </it>= 0.002). BTD levels were lowered in all cancer grades (I-IV) except cancer grade zero. The area under the receiver operating characteristic curve of BTD was 0.78. Estrogen receptor status (<it>p </it>= 0.940) and progesterone receptor status (<it>p </it>= 0.440) were not associated with the plasma BTD levels.</p> <p>Conclusions</p> <p>Our study suggests that BTD is a potential serological biomarker for the detection of breast cancer.</p

Can a routine follow-up blood culture be justified in Klebsiella pneumoniae bacteremia? a retrospective case–control study

Background : The need for mandatory confirmation of negative conversion in Klebsiella pneumoniae bacteremia (KpB) has not been adequately addressed. We conducted a retrospective case–control study of adult patients with KpB over a 5-year period in two tertiary-care hospitals to determine the risk factors for persistent bacteremia and to reevaluate the necessity of follow-up blood culture in KpB. Methods : Persistent KpB is defined as the finding of K. pneumoniae in more than two separate blood-culture samples for longer than a two-day period in a single episode. The case- and control-groups were patients with persistent and non-persistent KpB, respectively, and they were matched 1-to-3 according to age and gender. Results : Among 1068 KpB episodes analyzed after excluding polymicrobial infection and repeated KpB, follow-up blood cultures were performed in 862 cases (80.7%), 62 of which (7.2%) were persistent. Independent risk factors for persistence were intra-abdominal infection, higher Charlsons comorbidity weighted index score, prior solid organ transplantation, and unfavorable treatment response, which was defined as positivity for at least two parameters among fever, leukocytosis, and no decrease of C-reactive protein on the second day after initial culture. A proposed scoring system using four variables, namely, intra-abdominal infection, nosocomial KpB, fever and lack of C-reactive protein decrease, the last two being assessed on the second day after the initial blood culture, showed that only 4.9% of the patients with no risk factors or with only intra-abdominal infection had persistent KpB. Conclusions : Though persistent KpB is uncommon, follow-up blood culture was performed in as many as 80% of the cases in this study. A more careful clinical assessment is warranted to reduce the cost and patient inconvenience involved in follow-up blood culture.Peer Reviewe

Nogo-A regulates myogenesis via interacting with Filamin-C

Among the three isoforms encoded by Rtn4, Nogo-A has been intensely investigated as a central nervous system inhibitor. Although Nogo-A expression is increased in muscles of patients with amyotrophic lateral sclerosis, its role in muscle homeostasis and regeneration is not well elucidated. In this study, we discovered a significant increase in Nogo-A expression in various muscle-related pathological conditions. Nogo−/− mice displayed dystrophic muscle structure, dysregulated muscle regeneration following injury, and altered gene expression involving lipid storage and muscle cell differentiation. We hypothesized that increased Nogo-A levels might regulate muscle regeneration. Differentiating myoblasts exhibited Nogo-A upregulation and silencing Nogo-A abrogated myoblast differentiation. Nogo-A interacted with filamin-C, suggesting a role for Nogo-A in cytoskeletal arrangement during myogenesis. In conclusion, Nogo-A maintains muscle homeostasis and integrity, and pathologically altered Nogo-A expression mediates muscle regeneration, suggesting Nogo-A as a novel target for the treatment of myopathies in clinical settings. © 2021, The Author(s).1

Proteomic Interrogation in Cancer Biomarker

Biomarkers factor into the diagnosis and treatment of almost every patient with cancer. The innovation in proteomics follows improvement of mass spectrometry techniques and data processing strategy. Recently, proteomics and typical biological studies have been the answer for clinical applications. The clinical proteomics techniques are now actively adapted to protein identification in large patient cohort, biomarker development for more sensitive and specific screening based on quantitative data. And, it is important for clinical, translational researchers to be acutely aware of the issues surrounding appropriate biomarker development, in order to facilitate entry of clinically useful biomarkers into the clinic. Here, we discuss in detail include the case research for clinical proteomics. Furthermore, we give an overview on the current developments and novel findings in proteomics-based cancer biomarker research. © Springer Nature Singapore Pte Ltd. 2021.FALS

A Validation Study of a Multiple Reaction Monitoring-Based Proteomic Assay to Diagnose Breast Cancer

Purpose: Currently, the standard screening tool for breast cancer is screening mammography. There have been many efforts to develop a blood-based diagnostic assay for breast cancer diagnosis; however, none have been approved for clinical use at this time. The purpose of this study was to determine the accuracy of a novel blood-based proteomic test for aiding breast cancer diagnosis in a relatively large cohort of cancer patients. Methods: A blood-based test using multiple reaction monitoring (MRM) measured by mass spectrometry to quantify 3 peptides (apolipoprotein C-1, carbonic anhydrase 1, and neural cell adhesion molecule L1-like protein) present in human plasma was investigated. A total of 1,129 blood samples from 575 breast cancer patients, 454 healthy controls, and 100 patients with other malignancies were used to verify and optimize the assay. Results: The diagnostic sensitivity, specificity, and accuracy of the MRM-based proteomic assay were 71.6%, 85.3%, and 77%, respectively; the area under the receiver operating characteristic curve was 0.8323. The proteomic assay did not demonstrate diagnostic accuracy in patients with other types of malignancies including thyroid, pancreatic, lung, and colon cancers. The diagnostic performance of the proteomic assay was not associated with the timing of blood sampling before or after anesthesia. Conclusion: The data demonstrated that an MRM-based proteomic assay that measures plasma levels of three specific peptides can be a useful tool for breast cancer screening and its accuracy is cancer-type specific. © 2019 Korean Breast Cancer Society.TRU

Profiling of vitreous proteomes from proliferative diabetic retinopathy and nondiabetic patients

Diabetes can lead to serious microvascular complications like proliferative diabetic retinopathy (PDR), which is the leading cause of blindness in adults. The proteomic changes that occur during PDR cannot be measured in the human retina for ethical reasons, but could be reflected by proteomic changes in vitreous humor. Thus, we considered that comparisons between the proteome profiles of the vitreous humors of PDR and nondiabetic controls could lead to the discovery of novel pathogenic proteins and clinical biomarkers. In this study, the authors used several proteomic methods to comprehensively examine vitreous humor proteomes of PDR patients and nondiabetic controls. These methods included immunoaffinity subtraction (IS)/2-DE/MALDI-MS, nano-LC-MALDI-MS/MS, and nano-LC-ESI-MS/MS. The identified proteins were subjected to the Trans-Proteomic Pipeline validation process. Resultantly, 531 proteins were identified, i.e., 415 and 346 proteins were identified in PDR and nondiabetic control vitreous humor samples, respectively, and of these 531 proteins, 240 were identified for the first time in this study. The PDR vitreous proteome was also found to contain many proteins possibly involved in the pathogenesis of PDR. The proteins described provide the most comprehensive proteome listing in the vitreous humor samples of PDR and nondiabetic control patients

Identification of circulating endorepellin LG3 fragment: Potential use as a serological biomarker for breast cancer

Comparative proteome analysis was performed on the cultured media of human nontumor and malignant breast cell lines, Hs578Bst and Hs578T, respectively, in search of a serological biomarker(s) for breast cancer. Proteins in the conditioned media were separated by 2-D PAGE and then visualized by silver-staining. Eight proteins changed differentially by more than twofold were identified by MALDI-TOF/TOF MS. Among the proteins identified, the terminal laminin-like globular (LG3) domain of endorepellin, which was recently reported as an antiangiogenesis factor, was decreased in the cancer cell line. We confirmed the bone morphogenic protein-1 (BMP-1) mediated cleavage site on the N-terminus of endorepellin LG3 fragment. This finding suggests that the LG3 fragment is specifically released by a BMP-1 driven limited proteolytic process. The protein was also detected in plasma by Western blot analysis and selected reaction monitoring (SRM). The plasma level of the endorepellin LG3 fragment was significantly lower in breast cancer patients compared to healthy donors (p = 0.017; n = 12). The LG3 protein concentration in the control plasma was measured at approximately 3.7 pmol/mL compared to 1.8 pmol/mL in plasma from the cancer patients. We suggest that these results support the potential use of the endorepellin LG3 fragment as a new serological biomarker for breast cancer.N