Cytokines are important for breast cell function, both as trophic hormones and as mediators of host defense mechanisms against @entity0 . Recently, inducible feedback suppressors of cytokine signalling ( @entity19933 / @entity4635 /SSI) have been identified, which decrease cell sensitivity to cytokines. We examined the expression of @entity19933 genes in 17 @entity0 and 10 @entity0 lines, in comparison with normal tissue and breast lines. We report elevated expression of @entity19933 -1-3 and CIS immunoreactive proteins within in situ @entity513 and infiltrating @entity513 relative to normal breast tissue. Significantly increased expression of @entity19933 -1-3 and CIS transcripts was also shown by quantitative in situ hybridisation within both @entity5 tissue and reactive stroma. CIS transcript expression was elevated in all 10 @entity5 lines, but not in control lines. However, there was no consistent elevation of other @entity19933 transcripts. CIS protein was shown by immunoblot to be present in all @entity5 lines at increased levels, mainly as the 47 kDa ubiquitinylated form. A potential proliferative role for CIS overexpression is supported by reports that CIS activates @entity3963 kinases, and by strong induction in transient reporter assays with an @entity3963 -responsive promoter. The in vivo elevation of @entity19933 gene expression may be part of the host/ @entity5 response or a response to autocrine/paracrine GH and prolactin. However, increased CIS expression in @entity0 lines appears to be a specific lesion, and could simultaneously shut down @entity11715 signalling by trophic hormones, confer resistance to host cytokines and increase proliferation through @entity3963 kinases.

Suppressor of cytokine signalling gene expression is elevated in XXXX .

@entity4635 :: ('8651', 'Gene') :: ['JAB'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer', 'breast carcinomas'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumour', 'cancer'] @entity3963 :: ('5594', 'Gene') :: ['ERK'] @entity513 :: ('MESH:D044584', 'Disease') :: ['ductal carcinomas'] @entity19933 :: ('1154', 'Gene') :: ['SOCS'] @entity11715 :: ('6776', 'Gene') :: ['STAT 5']
@entity0 :: (MESH:D001943,Disease) :: ['breast carcinoma']
