GLUT 5 is not over-expressed in breast cancer cells and patient breast cancer tissues

F18 2-Fluoro 2-deoxyglucose (FDG) has been the gold standard in positron emission tomography (PET) oncologic imaging since its introduction into the clinics several years ago. Seeking to complement FDG in the diagnosis of breast cancer using radio labeled fructose based analogs, we investigated the expression of the chief fructose transporter-GLUT 5 in breast cancer cells and human tissues. Our results indicate that GLUT 5 is not over-expressed in breast cancer tissues as assessed by an extensive immunohistochemistry study. RT-PCR studies showed that the GLUT 5 mRNA was present at minimal amounts in breast cancer cell lines. Further knocking down the expression of GLUT 5 in breast cancer cells using RNA interference did not affect the fructose uptake in these cell lines. Taken together these results are consistent with GLUT 5 not being essential for fructose uptake in breast cancer cells and tissues.     

乳腺癌早期筛查和诊断生物标志物研究进展

2020年全球乳腺癌(breast cancer,BC)新发病例达226万例,占全部肿瘤新发病例的11.7%,是全世界发病率最高的癌症。早期发现、早期诊断和早期治疗是降低乳腺癌死亡率及改善预后的关键。尽管乳房X光筛查被广泛用作乳腺癌筛查的工具,但其假阳性、辐射性和过度诊断仍是亟待解决的问题。因此,亟需开发易于获取且稳定可靠的生物标志物,用于乳腺癌无创筛查和诊断。近年来多项研究显示来自乳腺癌患者血液中的循环肿瘤细胞DNA(circulating tumor cell DNA,ctDNA)、癌胚抗原(carcinoembryonic antigen,CEA)、糖类抗原15-3(carbohydrate antigen 15-3,CA15-3)、细胞外囊泡(extracellular vesicles,EV)、循环miRNA和BRCA基因突变等生物标志物,以及来自人体尿液、呼出气体(volatile organic compounds,VOCs)和乳头吸出液(nipple aspirate fluid,NAF)中的磷脂、miRNA、苯乙酮和十六烷等多种生物标志物与乳腺癌早期筛查和诊断密切相关。本文综述了上述生物标志物在乳腺癌早期筛查和诊断中的应用。     

Computer-aided diagnosis of breast cancer using cytological images: A systematic review

Cytological evaluation by microscopic image-based characterization [imprint cytology (IC) and fine needle aspiration cytology (FNAC)] plays an integral role in primary screening/detection of breast cancer. The sensitivity of IC and FNAC as a screening tool is dependent on the image quality and the pathologist’s level of expertise. Computer-aided diagnosis (CAD) is used to assists the pathologists by developing various machine learning and image processing algorithms. This study reviews the various manual and computer-aided techniques used so far in breast cytology. Diagnostic applications were studied to estimate the role of CAD in breast cancer diagnosis. This paper presents an overview of image processing and pattern recognition techniques that have been used to address several issues in breast cytology-based CAD including slide preparation, staining, microscopic imaging, pre-processing, segmentation, feature extraction and diagnostic classification. This review provides better insights to readers regarding the state of the art the knowledge on CAD-based breast cancer diagnosis to date.     

Hybrid methods for automated diagnosis of breast tumors

OBJECTIVE: To design and analyze a new family of hybrid methods for the diagnosis of breast tumors using fine needle aspirates. STUDY DESIGN: We present a radically new approach to the design of diagnosis systems. In the new approach, a nonlinear classifier with high sensitivity but low specificity is hybridized with a linear classifier having low sensitivity but high specificity. Data from the Wisconsin Breast Cancer Database are used to evaluate, computationally, the performance of the hybrid classifiers. RESULTS: The diagnosis scheme obtained by hybridizing the nonlinear classifier ellipsoidal multisurface method (EMSM) with the linear classifier proximal support vector machine (PSVM) was found to have a mean sensitivity of 97.36% and a mean specificity of 95.14% and was found to yield a 2.44% improvement in the reliability of positive diagnosis over that of EMSM at the expense of 0.4% degradation in the reliability of negative diagnosis, again compared to EMSM. At the 95% confidence level we can trust the hybrid method to be 96.19-98.53% correct in its malignant diagnosis of new tumors and 93.57-96.71% correct in its benign diagnosis. CONCLUSION: Hybrid diagnosis schemes represent a significant paradigm shift and provide a promising new technique to improve the specificity of nonlinear classifiers without seriously affecting the high sensitivity of nonlinear classifiers.     

The anti-apoptotic protein lifeguard is expressed in breast cancer cells and tissues

Lifeguard (LFG) is an anti-apoptotic protein that inhibits Fas-mediated death in tumour cells. However, the molecular function of human LFG in the carcinogenesis of human breast cells is uncertain. We studied the expression and function of endogenous LFG in four breast cancer cell lines (MCF-7, MDA-MB-231, T-47D and HS 578T), a human breast epithelial cell line (HS 578Bst), and in healthy and cancerous breast tissues. Molecular (Western blot and RT-PCR) and immunohistochemical techniques were used to investigate the LFG expression. To investigate the breast cancer cell proliferation in the presence of Fas, we performed fluorescent cell viability assays. The possible association of Fas with LFG was analyzed by immunofluorescence microscopy. In this paper, we provide convincing evidence that LFG is overexpressed in several human breast cancer cell lines. More importantly, we found that the LFG expression correlates with high tumour grades in primary breast tumours. Finally, we demonstrated that Fas sensitivity is reduced in breast cancer cell lines expressing LFG. Our results indicated that LFG is strongly expressed in breast cancer epithelial cells. Moreover, the overexpression of LFG correlated with tumour grade and reduced Fas sensitivity. Our findings support the idea that LFG may have a role in the downregulation of apoptosis in breast cancer cells.     

磷酸化蛋白质组学在三阴性乳腺癌诊治研究中的进展

三阴性乳腺癌是乳腺癌中恶性程度最高的亚型,其治疗仍以化疗为主,但容易出现耐药,且患者预后较差。随着蛋白质组学技术的发展,磷酸化蛋白质组学研究取得了长足的进步,并在肿瘤发生发展机制和诊治研究中得到了广泛的应用。同样,磷酸化蛋白质组学在三阴性乳腺癌的发生发展、靶向治疗和耐药机制研究等方面也发挥着重要作用。本文主要对目前磷酸化蛋白质组学在三阴性乳腺癌中的研究进展进行综述,旨在为基于磷酸化蛋白质组学的三阴性乳腺癌发生发展机制和诊治研究提供指导和帮助。     

Evaluation of chromogranin A expression in serum and tissues of breast cancer patients

Human chromogranin A (CgA) is a member of the granin family and is widely distributed in large dense core granules of endocrine and neuroendocrine cells. A variety of non-neuroendocrine carcinomas arising in various tissues show patterns of neuroendocrine differentiation. Expression of CgA has been documented in epithelial cells of normal mammary gland as well as in breast cancers, and elevation of serum CgA has been detected in patients with breast cancer. Our study was undertaken to evaluate the relationship between serum CgA levels and neuroendocrine features in breast cancer. In addition, we evaluated the expression of serum CgA in patients affected by breast cancer compared to controls and the relationship between serum CgA and tumor histology, extent of disease, lymph node status, tumor stage and serum CA 15.3 levels. We enrolled 266 patients with infiltrating ductal or lobular breast carcinoma and a group of 100 age-matched healthy women serving as controls. Serum CgA and CA 15.3 were assayed by specific immunoradiometric methods. The overall sensitivity of CgA and CA 15.3 was 0.06 and 0.34, respectively (chi2 19.1, p<0.0005). No relationship was found between serum levels of CgA and tumor histology, extent of disease, lymph node status or tumor stage while serum levels of CA 15.3 were strongly correlated with all these variables but tumor histology. No relationship was found between serum levels of CgA and CA 15.3. Immunostaining against CgA, CgB, NSE and synaptophysin was performed on primary tumor tissue of 14 serum CgA-positive and 24 serum CgA-negative patients and was negative in all cases. We also evaluated eight cases of pathologically-proven neuroendocrine breast cancer: only four and two of these showed positive CgA immunostaining and increased serum CgA concentration, respectively. In conclusion, serum CgA assay offers no additional information regarding the presence, the extent and the histology of breast cancer compared to the CA 15.3 assay. Moreover, serum CgA was not an accurate marker to identify or exclude the rare neuroendocrine differentiation of breast cancer. We therefore conclude that CgA is not useful as a serum marker in breast cancer.     

Amplification methods for the immunolocalization of rare molecules in cells and tissues

The needs to precisely assign macromolecules to specific locations and domains within tissues and cells and to reveal antigens which are present in low or even in trace amounts, led to the elaboration of a wide spectrum of immunocytochemical amplification procedures. These arise from the successive improvements of tissue preparation techniques, of antigen retrieval procedures and of immunological or non-immunological detection systems. Improvement of detection systems may be the most active in the development of amplification techniques. Since the early work of Coons, in which by the introduction of the indirect technique has started amplifying the signal, different systems have succeeded in increasing the sensitivity of antigens detection. Indeed, amplification techniques such as the multiple antibody layers, the multiple bridges, the enzyme complexes, the avidin-biotin, the silver intensification, and the numerous variations and combinations among these have increased the sensitivity for the detection of scarce tissue antigens. However, as shown by the recent progress carried out with new approaches such as the catalyzed reporter deposition (CARD) and the enhanced polymer one-step staining (EPOS), more efficient methods are still needed. In electron microscopy, few techniques have reached the resolution afforded by the post-embedding immunogold approach. In spite of this and in order to further increase its sensitivity, new probes and novel approaches are allowing combination of the gold marker with the amplification capacity of enzymes afforded by the CARD technique. Immunogold amplification strategies, such as the multiple incubations with the primary antibody and the use of an anti-protein A antibody have also led to enhanced signals displaying the advantages in terms of resolution and possibilities of quantification inherent to the colloidal gold marker.     

A comprehensive evaluation of multicategory classification methods for microarray gene expression cancer diagnosis

MOTIVATION: Cancer diagnosis is one of the most important emerging clinical applications of gene expression microarray technology. We are seeking to develop a computer system for powerful and reliable cancer diagnostic model creation based on microarray data. To keep a realistic perspective on clinical applications we focus on multicategory diagnosis. To equip the system with the optimum combination of classifier, gene selection and cross-validation methods, we performed a systematic and comprehensive evaluation of several major algorithms for multicategory classification, several gene selection methods, multiple ensemble classifier methods and two cross-validation designs using 11 datasets spanning 74 diagnostic categories and 41 cancer types and 12 normal tissue types. RESULTS: Multicategory support vector machines (MC-SVMs) are the most effective classifiers in performing accurate cancer diagnosis from gene expression data. The MC-SVM techniques by Crammer and Singer, Weston and Watkins and one-versus-rest were found to be the best methods in this domain. MC-SVMs outperform other popular machine learning algorithms, such as k-nearest neighbors, backpropagation and probabilistic neural networks, often to a remarkable degree. Gene selection techniques can significantly improve the classification performance of both MC-SVMs and other non-SVM learning algorithms. Ensemble classifiers do not generally improve performance of the best non-ensemble models. These results guided the construction of a software system GEMS (Gene Expression Model Selector) that automates high-quality model construction and enforces sound optimization and performance estimation procedures. This is the first such system to be informed by a rigorous comparative analysis of the available algorithms and datasets. AVAILABILITY: The software system GEMS is available for download from http://www.gems-system.org for non-commercial use. CONTACT: alexander.statnikov@vanderbilt.edu.     

A review of fluorescence methods for assessing labile iron in cells and biological fluids

A variety of biochemical, pharmacological, and toxicological properties have been attributed to labile forms of iron that are associated with cells or with biological fluids. Unlike the major fraction of bioiron which is protein bound, the labile bioiron is chelatable and therefore amenable for detection by metal-sensing devices that are coupled to chelation moieties. The present review deals with the detection of various labile forms of iron present in living cells and in fluids of biological interest, in health and disease. The main focus of the review is on the design and application of fluorescent probes as analytical tools for assessing labile iron and iron transport mechanisms and the efficiency of iron chelators in solution and in cellular systems.     

Comparative proteome analysis of breast cancer and adjacent normal breast tissues in human

Two-dimensional polyacrylamide gel assisted laser desorption/ionization electrophoresis （2D-PAGE） and matrixtandem time-of-flight mass spectrometry （MALDI-TOF/TOF-MS）, incorporated with online database searching, were performed to investigate differential proteins of breast cancer and adjacent normal breast tissues. Considering that serum albumin is abundantly presented in normal control samples, 15 differential spots detected in 11 out of 12 （91.7%） breast cancer samples were identified by online SIENA-2DPAGE database searching and MALDI-TOF/TOF-MS analysis. The results indicate that pathological changes of breast cancer are concerned with augmentation of substance metabolism, promotion of proteolytic activity, decline of activity of some inhibitors of enzymes, and so on. Some important proteins involved in the pathological process of breast cancer with changed expression may be useful biomarkers, such as alpha-l-antitrypsin, EF- 1-beta, cathepsin D, TCTP, SMT3A, RPS12, and PSMA1, among which SMT3A, RPSl2, and PSMA1 were first reported for breast cancer in this study.     

Abnormal expression, localization and interaction of canonical transient receptor potential ion channels in human breast cancer cell lines and tissues: a potential target for breast cancer diagnosis and therapy

Background  

Ca²⁺ is known to be involved in a number of metastatic processes including motility and proliferation which can result in store-depletion of Ca²⁺. Up regulation of genes which contribute to store operated channel (SOC) activity may plausibly be necessary for these processes to take place efficiently. TRPC proteins constitute a family of conserved Ca²⁺-permeable channels that have been shown to contribute to SOC activity.