BACKGROUND: Neurotrophins are growth factors that regulate cell growth, differentiation and apoptosis in the nervous system. Their diverse actions are mediated through two different transmembrane - receptor signaling systems: @entity2250 receptor @entity669 kinases ( @entity2250 , @entity12715 , @entity13820 ) and @entity7169 @entity2252 receptor. @entity2250 receptors promote cell survival and differentiation while @entity7169 induces, in most cases, the activity of @entity4675 -p53- @entity589 apoptosis pathway or suppresses intracellular survival signaling cascades. Robust @entity2250 activation blocks @entity7169 -induced apoptosis by suppressing the @entity4675 -p53- @entity589 pathway. The aim of this exploratory study was to investigate the expression levels of @entity2252 receptors, Trks and @entity7169 , and the activation of @entity4675 pathway in @entity1 @entity816 and in adjacent non-neoplastic brain tissue. METHODS: Formalin-fixed paraffin-embedded serial sections from 33 supratentorial @entity816 (5 diffuse @entity816 , WHO grade II; 6 @entity816 , WHO grade III; 22 @entity463 multiforme, WHO grade IV) were immunostained following microwave pretreatment. Polyclonal antibodies against @entity2250 , @entity12715 , @entity13820 and monoclonal antibodies against @entity7169 and phosphorylated forms of @entity4675 (pJNK) and @entity1178 (pc- @entity1178 ) were used. The @entity894 ( @entity894 ), defined as the percentage of positive (labeled) cells out of the total number of @entity5 cells counted, was determined. RESULTS: Moderate to strong, granular cytoplasmic immunoreactivity for @entity2250 , @entity12715 and @entity13820 receptors was detected in greater than or equal to 10% of @entity5 cells in the majority of @entity5 independently of grade; on the contrary, @entity7169 receptor expression was found in a small percentage of @entity5 cells (approximately 1%) in some @entity5 . The endothelium of @entity5 capillaries showed conspicuous immunoreactivity for @entity12715 receptor. @entity2250 immunoreactivity seemed to be localized in some neurons and astrocytes in non-neoplastic tissue. Phosphorylated forms of @entity4675 (pJNK) and @entity1178 (pc- @entity1178 ) were significantly co-expressed in a @entity5 grade-dependent manner (p < 0.05). Interestingly, a statistically significant (p < 0.05) reverse relationship between @entity2250 receptors LIs and pc- @entity1178 /pJNK LIs was noted in some @entity463 multiforme. CONCLUSION: In the context of @entity816 , @entity2250 receptors ( @entity2250 , @entity12715 , @entity13820 ) expression may promote @entity5 growth independently of grade. Furthermore, activation of @entity4675 pathway may contribute to progression towards @entity5 . Considering the fact that regional @entity5 heterogeneity may be a limiting factor for immunohistochemical studies, the significance of the reverse relationship between @entity2250 receptors and pc- @entity1178 /pJNK LIs with respect to biological behavior of @entity1 @entity816 requires further evaluation.

@entity2252 receptors expression and @entity4675 pathway activation in @entity1 XXXX .

@entity1 :: ('9606', 'Species') :: ['human'] @entity7169 :: ('4804', 'Gene') :: ['p75NTR'] @entity589 :: ('581', 'Gene') :: ['Bax'] @entity894 :: ('MESH:C566784', 'Disease') :: ['LI', 'labeling index'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors', 'malignancy'] @entity13820 :: ('4916', 'Gene') :: ['TrkC'] @entity1178 :: ('3725', 'Gene') :: ['Jun', 'c-Jun'] @entity2252 :: ('627', 'Gene') :: ['neurotrophin'] @entity4675 :: ('5599', 'Gene') :: ['JNK'] @entity816 :: ('MESH:D001254', 'Disease') :: ['astrocytomas', 'fibrillary astrocytomas', 'anaplastic astrocytomas'] @entity2250 :: ('4914', 'Gene') :: ['Trk', 'TrkA'] @entity669 :: ('CHEBI:18186', 'Chemical') :: ['tyrosine'] @entity463 :: ('MESH:D005909', 'Disease') :: ['glioblastomas'] @entity12715 :: ('4915', 'Gene') :: ['TrkB']
@entity816 :: (MESH:D001254,Disease) :: ['astrocytomas']
