S100A9 expression in invasive ductal carcinoma of the breast: S100A9 expression in adenocarcinoma is closely associated with poor tumour differentiation.

S100A9 is associated with myelomonocytic cell differentiation and is also expressed in some epithelia. However, there have been few studies on S100A9 in adenocarcinoma (AC) because the expression in normal epithelia is limited to squamous epithelia. Our previous studies on pulmonary AC and liver carcinomas suggested that S100A9 expression in carcinomas of glandular cell origin is related to poor tumour differentiation. In this study, we examined S100A9 expression in invasive breast carcinoma and evaluated the relation of the expression to the tumour differentiation in 70 cases of invasive ductal carcinoma (IDC) of the breast. S100A9 gene and protein expression was detected in MCF-7 breast carcinoma cells. The rate of S100A9 immunopositivity in IDC showed a higher correlation with poor tumour differentiation, especially in nuclear pleomorphism (P=0.0002) and mitotic activity (P=0.0001). Furthermore, transcriptional expression of S100A9 in sections of IDC could be detected in cases with a high S100A9 immunopositivity. No significant differences in the number of myelomonocytic cells expressing S100A9 were found among cases. There was no correlation between S100A9 immunopositivity and lymph node metastasis (P=0.32). S100A9 immunopositivity in non-invasive ductal carcinoma was also associated with poor tumour differentiation. No immunopositive reaction was observed in invasive lobular carcinomas with a classic cytological appearance and non-neoplastic duct cells. We conclude that S100A9 in glandular epithelial cells is newly expressed under cancerous conditions and is over-expressed in poorly differentiated AC.

Effects of tea catechins on the ERE-regulated estrogenic activity.

Tea catechins exert many biological effects, including anticancer and antibacterial activities. Also, it is reported that some plant flavonoids exhibit estrogenic activity. In this study, we investigated estrogenic or antiestrogenic activities of catechins in HeLa cells transiently transfected with an estrogen response element (ERE)-regulated luciferase reporter and an estrogen receptor (ER) alpha or ERbeta expression vector. Catechins alone did not induce luciferase (luc) activity in either of the ERs. Addition of 17beta-estradiol (E2) plus epicatechin gallate (ECG) or epigallocatechin gallate (EGCG) at 5 x 10(-6) M resulted in significant decreases in the ERalpha-mediated luc activity compared with that of E2 alone. On the contrary, lower concentrations significantly increased the E2-induced luc activity. Similar effects were observed with tamoxifen. The ERbeta-mediated estrogenic activities were stimulated by catechins. In conclusion, some catechins, particularly EGCG, were antiestrogenic for ERalpha at higher doses, and co-estrogenic for ERalpha at lower doses and for ERbeta. The lower doses were found in human plasma after tea-drinking. In addition, some catechins may be antiendocrine disruptors because they suppressed bisphenol A-induced luc activities.

Transcriptional regulation by C/EBP alpha and -beta in the expression of the gene for the MRP14 myeloid calcium binding protein.

Transcriptional regulation of the gene for the myeloid calcium binding protein, MRP14, was investigated in human monocytic leukemia cell lines. The MRP14 gene was not expressed in monoblastic ML-1 cells, promonocytic U-937 cells, or promyelocytic HL-60 cells. On the other hand, the gene was expressed in monocytic THP-1 cells and in the HL-60 cells treated with 1,25-dihydroxyvitamin D3 (VD3). The level of MRP14 in VD3-treated HL-60 cells was two-fold higher than that in THP-1 cells. Among several known transcription factor binding motifs, nuclear protein(s) of VD3-treated HL-60 cells and THP-1 cells bound to the CCAAT/enhancer binding protein (C/EBP)-binding motif that was located in the upstream region of the MRP14 gene (-81), as evidenced by the competitive gel mobility-shift assay. An antibody for C/EBP alpha super-shifted the nucleoprotein complex in THP-1 cells but not in the VD3-treated HL-60 cells, whereas an antibody for C/EBP beta blocked the formation of the complex with the nuclear factor of the HL-60 cells but not with that of THP-1 cells. An anti-C/EBP delta antibody had no effect on the complex in either cell. Thus, it was concluded that C/EBP alpha and -beta were able to bind to the C/EBP motif, and that C/EBP alpha bound to the motif in THP-1 cells and C/EBP beta bound to that in the VD3-treated HL-60 cells. Furthermore, to examine the transcriptional activity of the C/EBP motif, we transfected several constructed luciferase reporter DNAs into HL-60 cells and THP-1 cells. The luciferase activity of the C/EBP motif in HL-60 cells was increased by VD3 treatment. The C/EBP motif in the MRP14 gene was confirmed to function as a regulatory region in VD3-treated HL-60 cells and THP-1 cells by the assay. Since C/EBP beta was also detected in VD3-untreated HL-60 cells by immunoblotting, VD3 activated C/EBP beta to bind to the motif, probably through post-translational modification.