Modern Tumor Marker Discovery in Urology: Surface Enhanced Laser Desorption and Ionization (SELDI)

During the last two decades, biomarker research has benefited from the introduction of new proteomic analytical techniques. In this article, we review the application of surface enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectroscopy in urologic cancer research. After reviewing the literature from MEDLINE on proteomics and urologic oncology, we found that SELDI-TOF is an emerging proteomic technology in biomarker discovery that allows for rapid and sensitive analysis of complex protein mixtures. SELDI-TOF is a novel proteomic technology that has the potential to contribute further to the understanding and clinical exploitation of new, clinically relevant biomarkers.     

Use of serological proteomic methods to find biomarkers associated with breast cancer

New technologies for the detection and therapy of early stage breast cancer are urgently needed. Pathological changes in breast might be reflected in proteomic patterns in serum. A proteomic tool was used to identify proteomic patterns in serum that distinguishes neoplastic from non-neoplastic disease within the breast. Preliminary results derived from the serum analysis from 54 unaffected women and 76 patients with breast cancer were analyzed by two-dimensional (2-D) electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry, HSP27 was found up-regulated while 14-3-3 sigma was down-regulated in the serum of breast cancer patients. The two protein biomarkers were then used to classify an independent set of 104 masked serum samples. The results showed that the protein pattern on 2-D gels can completely segregate the serum of breast cancer from non-cancer. The discriminatory pattern correctly identified all 69 breast cancer cases in the masked set. Of the 35 cases of non-malignant disease, 34 were recognized as non-cancer. These findings justify a prospective population-based assessment of proteomic technology as a screening or diagnostic tool for breast cancer in high-risk and general populations. These two protein biomarkers could also be used as targets for further study in drug design and breast cancer therapy.     

Metabolic syndrome and urologic diseases

Metabolic syndrome (MetS) is a complex entity consisting of multiple interrelated factors including insulin resistance, central adiposity, dyslipidemia, endothelial dysfunction and atherosclerotic disease, low-grade inflammation, and in males, low testosterone levels. MetS has been linked to a number of urologic diseases including nephrolithiasis, benign prostatic hyperplasia and lower urinary tract symptoms, erectile dysfunction, male infertility, female incontinence, and prostate cancer. This article reviews the relationships between MetS and these entities. Urologists need to be cognizant of the impact that MetS has on urologic diseases as well as on overall patient health.     

Smoking: Its Impact on Urologic Health

Tobacco use remains the single largest preventable cause of disease and premature death in the United States, and smoking is a leading cause of cancer and death from cancer. There is also evidence that smoking is associated with several urologic diseases. Urologists have a unique opportunity to help our patients lead healthy lifestyles, which includes ending their dependence on nicotine and tobacco. This article points out the various urologic conditions associated with smoking and tobacco use with the intention of providing physicians and patients with knowledge and education regarding this connection.Key words: Bladder cancer, Prostate cancer, Kidney cancer, Erectile dysfunction, Interstitial cystitisSmoking remains one of the greatest health threats to our nation, and the death rate among current smokers is two to three times that of nonsmokers.¹ There is also evidence that smoking is associated with several urologic diseases. If we are to be effective healthcare providers, urologists must make a concerted effort to make our patients aware of the connections between tobacco and common urologic diseases. Also, urologists are in the unique position to motivate patients to stop smoking and to enter smoking cessation programs. This article points out the various urologic conditions associated with smoking and tobacco use with the intention of providing physicians and patients with knowledge and education regarding this connection.     

SELDI-TOF MS Proteomics in Breast Cancer

Background

Proteomic profiling is a rapidly developing technology that may enable early disease screening and diagnosis. Surface-enhanced laser desorption ionization–time of flight mass spectrometry (SELDI-TOF MS) has demonstrated promising results in screening and early detection of many diseases. In particular, it has emerged as a high-throughput tool for detection and differentiation of several cancer types. This review aims to appraise published data on the impact of SELDI-TOF MS in breast cancer.

Methods

A systematic literature search between 1965 and 2009 was conducted using the PubMed, EMBASE, and Cochrane Library databases. Studies covering different aspects of breast cancer proteomic profiling using SELDI-TOF MS technology were critically reviewed by researchers and specialists in the field.

Results

Fourteen key studies involving breast cancer biomarker discovery using SELDI-TOF MS proteomic profiling were identified. The studies differed in their inclusion and exclusion criteria, biologic samples, preparation protocols, arrays used, and analytical settings. Taken together, the numerous studies suggest that SELDI-TOF MS methodology may be used as a fast and robust approach to study the breast cancer proteome and enable the analysis of the correlations between proteomic expression patterns and breast cancer.

Conclusion

SELDI-TOF MS is a promising high-throughput technology with potential applications in breast cancer screening, detection, and prognostication. Further studies are needed to resolve current limitations and facilitate clinical utility.     

Clinical proteomics: towards early detection of cancers

A key challenge in clinical proteomic of cancer is the identification of biomarkers that would allow early detection, diagnosis and monitor progression of the disease to improve long-term survival of patients. Recent advances in proteomic instrumentation and computational methodologies offer unique chance to rapidly identify these new candidate markers or pattern of markers. The combination of retentate affinity chromatography and surfaced-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry is one of the most interesting new approaches for cancer diagnostic using proteomic profiling. This review aims to summarize the results of studies that have used this new technology method for the early diagnosis of human cancer. Despite promising results, the use of the proteomic profiling as a diagnostic tool brought some controversies and technical problems and still requires some efforts to be standardised and validated.     

Proteomics approaches to urologic diseases

Biomarkers are greatly needed for several urologic diseases, such as interstitial cystitis, the symptomatic and clinical progression of benign prostate hyperplasia, as well as the specific detection of urologic cancers, including prostate and bladder cancer. This review aims to: briefly describe the need for biomarkers in the field and biomarkers that are currently available for clinicians; address the limitations and roadblocks to effective biomarker discovery; and provide examples and strategies for implementing biomarkers in clinical practice and/or drug discovery.     

Clinical proteomics: present and future prospects

Advances in proteomics technology offer great promise in the understanding and treatment of the molecular basis of disease. The past decade of proteomics research, the study of dynamic protein expression, post-translational modifications, cellular and sub-cellular protein distribution, and protein-protein interactions, has culminated in the identification of many disease-related biomarkers and potential new drug targets. While proteomics remains the tool of choice for discovery research, new innovations in proteomic technology now offer the potential for proteomic profiling to become standard practice in the clinical laboratory. Indeed, protein profiles can serve as powerful diagnostic markers, and can predict treatment outcome in many diseases, in particular cancer. A number of technical obstacles remain before routine proteomic analysis can be achieved in the clinic; however the standardisation of methodologies and dissemination of proteomic data into publicly available databases is starting to overcome these hurdles. At present the most promising application for proteomics is in the screening of specific subsets of protein biomarkers for certain diseases, rather than large scale full protein profiling. Armed with these technologies the impending era of individualised patient-tailored therapy is imminent. This review summarises the advances in proteomics that has propelled us to this exciting age of clinical proteomics, and highlights the future work that is required for this to become a reality.     

Algorithms of x-ray and ultrasonic diagnoses in urology]

Roentgenourologic methods and ultrasonic scanning (USS) should be combined in the radiologic diagnosis of urologic diseases. USS should be the first stage of examinations of urologic patients, and its results should be taken into account when planning and carrying out excretory urography. USS can be repeated before more sophisticated roentgenourologic examinations in order to single out the "zones of interest"; special programmes are possible for the purpose-pharmacoechography, dopplerography, etc. Development of tentative algorithms of x-ray and ultrasonic diagnosis of the major urologic diseases will help optimize the diagnostic process.     

Role of JAK/STAT signaling in neuroepithelial stem cell maintenance and proliferation in the Drosophila optic lobe

Human urine contains a large number of proteins and peptides (the urinary proteome). Global analysis of the human urinary proteome is important for understanding urinary tract diseases. Bladder cancer is the most common urological cancer with higher incidence rates in endemic areas of Blackfoot disease (BFD) in southern Taiwan. The aim of this study was to use the proteomic approach to establish urinary protein biomarkers of bladder cancer. ADAM28, identified by proteomic approaches and confirmed by Western blotting, showed significant differences compared with normal individuals, so it may be a biomarker of bladder cancer.     

Toward multimodality oral cancer diagnosis in the XXI century: Blending cutting edge imaging and genomic/proteomic definition of suspicious lesions

If emergent genomic and proteomic approaches to early oral cancer detection are to be successful, a means of reliably and comprehensively identifying high-risk tissue sampling sites constitutes an essential step in the oral cancer screening process. Recent studies have determined that in vivo Optical Coherence Tomography (OCT) is a quick and user-friendly tool for detecting and mapping oral lesions, and that it can enhance diagnostic accuracy when using high resolution diagnostic techniques such as in vivo microscopy. Therefore OCT can potentially provide a means of improving the clinical usefulness of novel diagnostic approaches such as proteomics by identifying sites that need to be sampled.     

Toward multimodality oral cancer diagnosis in the XXI century: Blending cutting edge imaging and genomic/proteomic definition of suspicious lesions

If emergent genomic and proteomic approaches to early oral cancer detection are to be successful, a means of reliably and comprehensively identifying high-risk tissue sampling sites constitutes an essential step in the oral cancer screening process. Recent studies have determined that in vivo Optical Coherence Tomography (OCT) is a quick and user-friendly tool for detecting and mapping oral lesions, and that it can enhance diagnostic accuracy when using high resolution diagnostic techniques such as in vivo microscopy. Therefore OCT can potentially provide a means of improving the clinical usefulness of novel diagnostic approaches such as proteomics by identifying sites that need to be sampled.     

表面增强激光解吸电离飞行时间质谱技术筛查肺癌血清特异性蛋白质及其临床意义

目的:探讨用表面增强激光解吸电离飞行时间质谱(SELDI-TOF-MS)技术筛查肺癌血清特异性蛋白质的临床意义。方法:应用SELDI-TOF-MS对35例正常对照组、43例治疗前肺癌病人的血清样品进行蛋白质指纹图谱测定,用BioMarker Wizard 3．01及BioMarker Parrern System 5．01分析软件对测得的数据进行处理及建立诊断模型。结果:共检测到251个蛋白质峰,筛选出差异蛋白质峰11个,以质荷比(m/z)分别为M2799_26,M3227_41,M5739_70和M8164_30的4个蛋白质峰为依据组合构建分类决策树模型,分出5个终节点。决策树模型的原始判别总准确率为91．0%(71/78),敏感性为88．4%(38/43),特异性为94．3%(33/35);交叉验证总准确率为85．9%(67/78),敏感性为88．4%(38/43),特异性为82．9%(29/35)。结论:SELDI-TOF-MS在肺癌血清特异性蛋白质的筛选及诊断模型的建立有一定的临床意义。     

蛋白质芯片SELDI-TOFMS技术的研究进展及其在临床中的应用

蛋白质芯片为新一代的蛋白质组研究技术,由美国Ciphergen生物系统公司引进,表面增强激光解吸电离-飞行时间质谱(SELDI-TOFMS)提供一个高通量和高灵敏度的检测平台。投放至今虽短短10来年,但卓越的成果已广为医学科学界重视,尤其在恶性肿瘤的早期诊断、监控和预后研究上。蛋白质是细胞内执行生物功能的最终分子,蛋白质组学研究让人类更深入了解疾病和生命的本源,不断发现的特异性肿瘤标志物更为攻克癌症带来新希望。这里除对表面增强激光解吸电离_飞行时间质谱作较详尽的介绍外,更重点阐述其近年来蛋白质芯片近期的研究进展和在临床中的应用,并就其优劣和发展前景作出评估。     

Production of active recombinant mitogen-activated protein kinases through transient transfection of 293T cells

Mitogen-activated protein (MAP) kinases are a family of serine/threonine protein kinases that play an important role in a myriad of cellular processes, including cell proliferation, differentiation, and apoptosis. Abnormal activation of MAP kinases has been shown to participate in a variety of human diseases which include cancer, septic shock, rheumatoid arthritis, diabetes, and cardiovascular diseases. Active MAP kinase enzymes are not only valuable for basic biomedical research but are also critical for the development of pharmacological inhibitors as therapeutic drugs in the treatment of relevant human diseases. MAP kinases produced in a bacterial system are poorly active due to a lack of proper phosphorylation at their characteristic threonine and tyrosine residues. To overcome these limitations, we have developed a mammalian expression system for high level expression and one-step purification of enzymatically MAP kinases. We cloned JNK1, p38, and p38-regulated MAP kinase-activated protein kinase-2 into the mammalian expression vector pEBG, and expressed these protein kinases as glutathione S-transferase fusion proteins in human embryonic kidney 293T cells through transient transfection. The protein kinases were activated in vivo through treating the transfected cells with sodium arsenite and affinity-purified using glutathione-Sepharose beads. The enzymatic activities of these protein kinases were demonstrated by Western blot analysis and in vitro kinase assays. Our results indicate that this system is an extremely powerful tool for generating valuable reagents, and could be very valuable for proteomic studies.     

The human urine mannose 6-phosphate glycoproteome

Glycoproteins containing the mannose 6-phosphate (Man-6-P) modification represent a class of proteins of considerable biomedical importance. They include over sixty different soluble lysosomal hydrolases and accessory proteins, deficiencies of which result in over forty different known human genetic diseases. In addition, there are patients with lysosomal storage diseases of unknown etiology and lysosomal proteins have been implicated in pathophysiological processes associated with Alzheimer disease, arthritis, and cancer. The aim of this study was to explore urine as a source for the proteomic investigation of lysosomal storage disorders as well as for biomarker studies on the role of Man-6-P containing proteins in other human diseases. To this end, urinary proteins were affinity purified on immobilized Man-6-P receptors, digested with trypsin, and analyzed using nanospray LC/MS/MS. This resulted in identification of 67 proteins, including 48 known lysosomal proteins and 9 proteins that may be lysosomal. The identification of a large proportion of the known set of soluble lysosomal proteins with relatively few contaminants suggests that urine represents a promising substrate for the development of comparative proteomic methods for the investigation of lysosomal disorders and other diseases involving Man-6-P glycoproteins.     

Proteomics in thyroid cancer and other thyroid-related diseases: A review of the literature

Misdiagnosis, over-diagnosis, or inappropriate treatment strategies are frequently seen in thyroid disease management. Currently, there is an urgent interest to identify biomarkers for specific disease states in the thyroid gland. Proteomics-based approaches have been widely used for the discovery of potential biomarkers in thyroid research. Specifically, proteomic techniques have been used to better understand thyroid tumors of different origin and classification. Besides, there is remarkable thyroid proteomics research in thyroid-related diseases, including thyroid orbitopathy. In this review, we aim to describe proteomic studies and how the results obtained from thyroid cancer, up to now, as well as those from, other thyroid-related diseases pose challenges, which might be solved via high-resolution protein analysis.