Tryptase(+) mast cells (MCs), abundant in the invasive front of tumours, contribute to tissue remodelling. Indeed, protease-activated receptor-2 (PAR-2) activation by MC-tryptase is considered an oncogenic event in colorectal cancer (CRC). Recently, we have suggested NHERF1 as a potential new marker in CRC. In this study, we aimed to determine the distribution of tryptase(+) MCs and PAR-2 and to examine the relationship between PAR-2 and NHERF1, investigating their reputed usefulness as tumour markers. We studied a cohort of 115 CRC specimens including primary cancer (C) and adjacent normal mucosa (NM) by immunohistochemical double staining, analyzing the protein expression of MC-tryptase, PAR-2 and cytoplasmic NHERF1. MC density was higher in NM than in C. Tumours with high TNM stage and poor grade showed the highest MC density. A higher PAR-2 immunoreactivity characterized tumours most infiltrated by MCs compared with samples with low MC density. Furthermore, PAR-2 overexpression was associated with advanced TNM stage, poor grade and lymphovascular invasion (LVI). A positive correlation existed between tryptase(+) MC density and PAR-2 expression. Cytoplasmic NHERF1 was higher in C than in NM and overexpressing tumours resulted associated with nodal and distant metastases, poor grade and LVI. PAR-2 correlated with cytoplasmic NHERF1 and the PAR-2(+)/cytoplasmic NHERF1(+) expression immunophenotype identified tumours associated with unfavourable prognosis and aggressive clinical parameters. Our data indicate that the high density of tryptase(+) MCs at invasive margins of tumours was associated with advanced stages of CRC and was strongly correlated with PAR-2 expression.

(Bush, 1995; Trewavas et al., 1996; Webb et al., 1996) and animal cells (Petersen et al., 1994; Bootman and Berridge, 1995 Tsien, 1990; Fewtrell, 1993; Petersen et al., 1994). For plant cells only a few reports about [Ca 2ϩ ] cy oscillations exist. Phytohormone-induced [Ca 2ϩ ] cy fluctuations reported earlier were strongly damped and ceased after a few repetitions (Felle, 1988; Schroeder and Hagiwara, 1990). Only recently stable [Ca 2ϩ ] cy oscillations were observed in plant cells (Johnson et al., 1995; McAinsh et al., 1995; Ehrhardt et al., 1996; Bauer et al., 1997). In some cases these [Ca 2ϩ ] cy oscillations display a baseline spiking pattern, which means that repetitive [Ca 2ϩ ] cy spikes are separated by a constant [Ca 2ϩ ] cy baseline (Ehrhardt et al., 1996; Bauer et al., 1997). There are indications for a physiological function of [Ca 2ϩ ] cy oscillations in plant cells (Johnson et al., 1995; McAinsh et al., 1995; Ehrhardt et al., 1996). The mechanisms generating [Ca 2ϩ ] cy oscillations in plant cells are unknown.The unicellular green alga Eremosphaera viridis responds to various stimuli with single or repetitive [Ca 2ϩ ] cy spikes (Bauer et al., 1997

TROP-2 can be used as well as HBME-1 in thyroid cytology to detect PTC. Positivity for either or both markers could help to stratify the risk of malignancy in indeterminate FNAs. Larger studies are need to analyse its role in the behaviour of PTC and its variants.

BackgroundIn clinical practice the gold standard method to assess BRAF status in patients with metastatic melanoma is based on molecular assays. Recently, a mutation-specific monoclonal antibody (VE1), which detects the BRAF V600E mutated protein, has been developed. With this study we aimed to confirm the clinical value of the VE1 Ventana® antibody, as today a univocal validated and accredited immunohistochemical procedure does not exist, to preliminary detect BRAF status in our routine diagnostic procedures. Moreover, we explored the biological meaning of BRAF immunohistochemical labeling both as a predictor marker of response to target therapy and, for the first time, as a player of acquired tumor drug resistance.MethodsWe analyzed a retrospective series of 64 metastatic melanoma samples, previously investigated for molecular BRAF status, using a fully automatized immunohistochemical method. We correlated the data to the clinicopathologic characteristics of patients and their clinical outcome.ResultsThe sensitivity and the specificity of the Ventana® VE1 antibody were 89.2 and 96.2% respectively, while the positive predictive value and negative predictive value were 97.1 and 86.2%, respectively. For six mutated patients the histological sample before treatment and when disease progressed was available. The immunohistochemical BRAF V600E expression in the specimens when disease progressed was less intense and more heterogeneous compared to the basal expression. Multivariate analysis revealed that a less intense grade of positive expression is an independent predictor of a less aggressive stage at diagnosis (p = 0.0413).ConclusionsOur findings encourage the introduction of immunohistochemistry as a rapid screening tool for the assessment of BRAF status in melanoma patients in routine diagnostic procedures and prepare the ground for other studies to highlight the role of immunohistochemical BRAF V600E expression in patients at the time of progression.