Search

Abstract: Objectives: The purpose of this study was to evaluate the efficacy of a protein-based pattern in serum previously determined by MALDI-TOF-MS (Matrix Assisted Laser Desorption Ionization-Time of Flight) and considered potentially useful for prediction of clinical outcome of EGFR (epidermal growth factor receptor) TKIs (tyrosine kinase inhibitors) treated patients. Design and methods: We generated SELDI-TOF (Surface Enhanced Laser Desorption Ionization-Time of Flight) spectra in sera of 11 advanced NSCLC treated with Gefitinib. We detected the clusters with m/z 5843, 11445, 11529, 11685, 11759 and 11903 which were previously reported to be potential predictors of response to Gefitinib treatment. Results: Four cluster peaks with m/z 5843, 11445, 11529, 11685 corresponded to SAA (serum amyloid A) protein on the basis on their calculated molecular weight, peptide fingerprinting and antibodies recognition. Conclusions: We confirm that several proteins already reported were isoforms of SAA but further studies are in development in order to evaluate the predictive value of such algorithm. [Copyright &y& Elsevier]

This is an observational retrospective study showing that hepcidin-25 and ferritin light chain are increased in malignant breast cancer and benign breast lesions compared with control individuals. A significant association between HER2 status and increased hepcidin-25 was also observed. Thus, assessment of plasma hepcidin-25 and iron-related parameters may improve breast cancer detection.Background Currently used CA15–3 and CEA have found their clinical application particularly in the follow-up of patients with advanced disease. Novel biomarkers are urgent, especially for improving early diagnosis as well as for discriminating between benign and malignant disease. Patients and methods In the present study, we used a proteomic approach based on surface-enhanced laser desorption/ionization–time of flight–mass spectrometry screening with the aim of identifying differentially expressed 2–30 kDa proteins in plasma of patients with malignant (65 cases) and benign (88 cases) breast lesions with respect to 121 healthy controls. Results We found that the most promising SELDI peaks were those corresponding to hepcidin-25 and ferritin light chain. We evaluated the capability of these peaks in predicting malignant and benign breast lesions using the area under the receiver operating characteristic curve (AUC). The results showed a good capacity to predict malignant breast lesions for hepcidin-25 [AUC: 0.82; 95% confidence interval (CI) 0.75–0.90] and ferritin light chain (AUC: 0.86; 95% CI 0.79–0.92). Conversely, a weak and satisfactory capability to predict benign breast lesion was observed for hepcidin-25 (AUC: 0.63; 95% CI 0.41–0.85) and ferritin light chain (AUC: 0.73; 95% CI 0.49–0.97). A significant association between HER2 status and hepcidin-25 was observed and the distribution of transferrin and ferritin were found significantly different in patients with breast cancer when compared with that of controls. Conclusions This study provides evidence that hepcidin and ferritin light chain level in plasma may be of clinical usefulness to predict malignant and benign disease with respect to healthy controls. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Breast cancer is the most common form of cancer affecting women, and the strongest risk factor remains family history. Although screening in asymptomatic women seems able to reduce breast-cancer related mortality, it is of limited usefulness in young women and patients with familial breast cancer syndrome. New diagnostic tools useful for breast cancer management are urgently needed. The aim of the present paper is to look for new candidate tumor markers useful for diagnosis in these patients. Design and methods: In this prospective study 292 serum samples (100 from healthy people, 100 from sporadic breast cancer patients and 92 from familial breast cancer patients) were analyzed by SELDI-TOF–MS. All samples both from cancer patients and healthy subjects were run in duplicate and randomly spotted on CM10 and IMAC30 protein chip array. Data were analyzed using the expression differential mapping (EDM) tool, decisional tree and multivariate analysis. A further in silico investigation was performed in order to hypothesize the identity of evidenced peptides. Results: EDM highlighted thirteen and sixteen significant differentially expressed peaks by CM10 and IMAC30 protein chip respectively. Subsequent analysis showed that two peaks at m/z 11730 and 5066 were differentially expressed in sporadic and familial breast cancer patients respectively, while a peak at m/z 8127 was overexpressed only in familial breast cancer patients. The diagnostic power of protein peaks was tested by decisional tree; sensitivity and specificity ranged from 17% to 91.67%. Conclusions: We show that the serum profile of familial breast cancer patients was different when compared with that of sporadic breast cancer patients. We hypothesized the identity of the most significant peaks, and further studies are now planned in order to definitively establish the identity. [Copyright &y& Elsevier]

The RET gene encodes two main isoforms of a receptor tyrosine kinase (RTK) implicated in various human diseases. Activating germ-line point mutations are responsible for multiple endocrine neoplasia type 2-associated medullary thyroid carcinomas, inactivating germ-line mutations for Hirschsprung's disease, while somatic rearrangements (RET/PTCs) are specific to papillary thyroid carcinomas. SH2B1β, a member of the SH2B adaptors family, and binding partner for several RTKs, has been recently described to interact with proto-RET. Here, we show that both RET isoforms and its oncogenic derivatives bind to SH2B1β through the SRC homology 2 (SH2) domain and a kinase activity-dependent mechanism. As a result, RET phosphorylates SH2B1β, which in turn enhances its autophosphorylation, kinase activity, and downstream signaling. RET tyrosine residues 905 and 981 are important determinants for functional binding of the adaptor, as removal of both autophosphorylation sites displaces its recruitment. Binding of SH2B1β appears to protect RET from dephosphorylation by protein tyrosine phosphatases, and might represent a likely mechanism contributing to its upregulation. Thus, overexpression of SH2B1β, by enhancing phosphorylation/activation of RET transducers, potentiates the cellular differentiation and the neoplastic transformation thereby induced, and counteracts the action of RET inhibitors. Overall, our results identify SH2B1β as a key enhancer of RET physiologic and pathologic activities.Oncogene (2007) 26, 6546–6559; doi:10.1038/sj.onc.1210480; published online 30 April 2007 [ABSTRACT FROM AUTHOR]

Abstract: We report the identification of proteins induced in response to RET/PTC2, an oncogene implicated in thyroid cancers. Anti-phosphotyrosine antibody affinity resin was used to purify Tyr(P)-containing and interacting proteins from 293T and NIH3T3 cells which were transfected with kinase active or inactive RET/PTC and RETMEN2 oncogenes. Proteins were separated by one-dimensional SDS-PAGE, extracted by in-gel digestion, and identified by MALDI-TOF peptide mass fingerprinting. The expression and tyrosine phosphorylation of Sam68, a protein implicated in mRNA nucleocytoplasmic translocation and splicing, were further examined in RET-transfected cells and thyroid tumors. Of relevance, cells transfected with RETMEN2B examined for anti-phosphotyrosine bound proteins, showed other proteins implicated in splicing: DEAD-box p68 RNA helicase, SYNCRIP, and hnRNP K. Western blotting analysis suggested that these proteins are singularly tyrosine phosphorylated in RETMEN2B-transfected cells, and that they constitutively bind with Sam68. The study concludes that regulation of splicing factors is likely to be important in RET-mediated thyroid carcinogenesis. [Copyright &y& Elsevier]