31 Our goal was to extend these observations using multiplex quantum dot labeling to search for an association between ERα expression and IL-6 expression and evidence of gp130 downstream signaling in a clinically relevant situation in human BECs in vivo. Results showed nuclear ERα expression was associated with cytoplasmic IL-6 protein expression and evidence of downstream gp130 signaling, manifest as nuclear pSTAT3 (Fig. 6A). Cystic BEC pSTAT3 expression was entirely blocked with recombinant pSTAT3 peptide (Fig. 6B). BEC from the normal liver (Fig. 6A), in contrast, were negative for IL-6 expression and showed only rare pSTAT3-positive
BECs; occasional portal-based periductal Selleck AZD6738 inflammatory cells expressed cytoplasmic IL-6 protein and pSTAT3 (Fig. 6). To determine the significance of estrogen signaling in PCL, we compared cyst BECs from three males and six premenopausal (<45 years)
and six postmenopausal (>55 years) women for immunohistochemical expression of ERα, IL-6, pSTAT3, and a variety of other growth factor and receptor proteins (vascular endothelial growth factor [VEGF], Flk-1, insulin-like growth factor 1 [IGF-1], phosphorylated IGF-1 receptor [pIGF-1R], epidermal growth factor receptor [EGFR], erythroblastic leukemia viral oncogene homolog 2 [Her2/ErbB-2]) which are known to be expressed on PCL BECs or in the cyst fluid. ERα and pSTAT3 showed a significant correlation to menopausal state. Male pSTAT3 was comparable to that of premenopausal women and likely influenced by other environmental factors Selumetinib datasheet (androgens and testosterone) or IGF-1/pIGF-1R, whose expression was slightly higher in male PCL (data not shown) (Fig. 6C). Although it is not surprising that ERα was higher in the premenopausal group, the correlation between pSTAT3 and menopausal status implicates ERα signaling in disease progression. Because many of the factors tested might influence IL-6 or manifest downstream signaling as pSTAT3, we analyzed PCL on the basis of pSTAT3 high and low expression. MCE公司 The only significant
relationship with pSTAT3 expression was IL-6 (Fig. 6D). Our results on differential regulation of BEC IL-6 mRNA and protein expression by ERα according to sex are consistent with previous studies showing that: (1) ERα expression is complex and regulated at the level of transcription, translation, and protein degradation by the ubiquitin-proteasome pathway32; (2) ERβ generally blocks or significantly reduces gene activation mediated by ERα16, 26; and (3) ERα is most closely correlated with a positive modulatory effect on BEC physiology.17 The following observations support these conclusions. Non-neoplastic female BECs and the male BEC cell line SG231 express significantly more ERα than non-neoplastic male BECs and the HuCCT-1 cell line.