trast to SLAMF1 and SLAMF6, SLAMF3 has a negative effect on the signalling pathways required for innate-like lymphocyte development in the thymus. The observed effect may be attributed to both decrease in the proliferation of cells over-expressing SLAMF3 and the induction of apoptosis. In the present work, we also observed an association 946387-07-1 between restoration of SLAMF3 expression in HCC cells and the significant inhibition of ERK and JNK phosphorylation, which are constitutively activated in HCC and associated with the malignant HCC phenotype. Other studies using in vivo HCC animal models and human HCC tissue specimens have evidenced greater MAPK ERK expression and activity in tumours relative to the surrounding tissue. TA-02 Indeed, ERK activity has clinical relevance since it positively correlated with tumour size and aggressive tumour behaviour and is considered to be an independent prognostic marker for poor overall survival . In human T cells, SLAMF3 engagement attenuates T-cell receptor signalling and reduces ERK activation. Murine T cells lacking SLAMF3 exhibit low Th2 responses. The JNK pathway is known to be a negative regulator of the p53 tumour suppressor and its role in cell survival is well established. Based on the correlation between elevated JNK kinase activity and tumour cell proliferation, it has been suggested that JNK has an oncogenic role. In contrast, reports of low p38 activity in HCC suggest that elevated p38 MAPK activity induces apoptosis in hepatoma cell lines. The members of the BCL2 family can function both as positive or negative regulators of apoptosis. It is interesting that this compound presented greater affinity for the b5 site than the covalent inhibitor bortezomib. Further optimization, guided by X-ray crystallography of compounds in complex with the purified yeast 20S, yielded a series of non-covalent di-peptide inhibitors of the proteasome with unprecedented in vitro and cellular potencies. The most active inhibitor reduced exclusively the ChT-L activity with IC50 = 7.4 nM. Moreover, Furet et al. analyzed pseudopeptides such as the 2-aminobenzylstatine derivatives that specifically inhibit the ChT-L site of the human proteasome with an IC50 value in the micromolar range. Gallastegui et al. presented non-peptidic hydroxyureas, whereas Formicola et al. described novel inhibitors o
