Expression of estrogen receptor-beta isoforms in Barrett's metaplasia, dysplasia and esophageal adenocarcinoma.

We have previously shown that the majority of esophageal adenocarcinomas (EA), and its precursor Barrett's metaplasia (BM), express estrogen receptor beta (ER-B). Several isoforms of ER-B have been described and are presumed to have different functions, but their distribution in BM and EA is not known. The aim of this work was to determine which ER-B isoforms are expressed in EA and BM. Sections of formalin-fixed and paraffin-embedded esophageal tissue from 33 esophageactomy specimens, of which 27 had invasive EA, were stained for the ER-B isoforms ER-B1, ER-B2, ER-B3 and ER-B5 utilizing the immunoperoxidase method ER-B1 was detected in 23 out of 27 (85%) EA compared to 3 out of 14 (21%) Barrett's metaplasia negative for dysplasia (BMND) (p =0. 0001); ER-B2 was expressed in 22 out of 27 (81%) EA in contrast to 3 out of 14 (21%) BMND (p=0.0004); ER-B3 was positive in 27 out of 27 (100%) EA in contrast to only 1 out of 14 (7%) BMND (p<0001); ER-B5 was detected in 27 out of 27 (100%) EA compared to 9 out of 14 (62%) of BMND (p=0.0027). High- and low-grade dysplasia showed a similar ER-beta isoform expression profile to that of EA Cancers invasive through the esophageal wall had a higher percent of cells with cytoplasmic expression of ER-B1 than tumors limited to the wall (T3 vs. T1 and T2, p=0.051). We conclude that ER-B1, ER-B2, ER-B3 and ER-B5 are overexpressed in EA compared to its precursor lesion BMND, suggesting a significant biological role for steroid hormones in EA.

The utility of p16INK4a and Ki-67 staining on cell blocks prepared from residual thin-layer cervicovaginal material.

BACKGROUND: Cell blocks can be prepared from residual thin-layer cervicovaginal (ThinPrep) material and can be used in immunohistochemical staining assays for p16INK4a and Ki-67, which are surrogate markers related to human papillomavirus infection and cell proliferation, respectively. The objectives of the current study were 1) to investigate the feasibility and the role of cell block preparations in identifying significant neoplastic and preneoplastic lesions of the uterine cervix and 2) to assess the feasibility of using p16INK4a and Ki-67 immunohistochemical staining patterns on cell blocks to identify significant preneoplastic cervical lesions. METHODS: Cervicovaginal cytology specimens from 85 patients were analyzed. Cytologic diagnoses based on ThinPrep Papanicolaou test results were as follows: squamous cell carcinoma was diagnosed in 3 specimens, high-grade squamous intraepithelial lesions (HSIL) were diagnosed in 27 specimens, low-grade squamous intraepithelial lesions (LSIL) were diagnosed in 20 specimens, and atypical squamous cells of uncertain significance (ASCUS) were diagnosed in 11 specimens. Diagnoses of negativity for intraepithelial lesions or malignancy (NILM) were made in 24 specimens. Cell block sections were stained with hematoxylin and eosin and were immunostained with antibodies against p16INK4a protein and Ki-67 antigen. RESULTS: The cytomorphologic diagnoses made using cell block preparations were as follows: SCC in 2 specimens, HSIL in 20 specimens, LSIL in 30 specimens, NILM in 32 specimens, and no diagnosis in 1 specimen. In 62 cases (73%), the diagnoses made using cell block preparations were in agreement with the ThinPrep diagnoses. Immunostaining of cell blocks for p16INK4a and Ki-67 exhibited a statistically significant association (P < 0.05) with the presence of significant lesions on either cell block or ThinPrep analysis. CONCLUSIONS: To the authors' knowledge, p16INK4a has not been analyzed previously in ThinPrep cell blocks, and the correlation between Ki-67 expression and cell block diagnoses also has not been reported previously. The current results indicate that cell blocks prepared from residual ThinPrep material represent an additional reliable diagnostic tool in the evaluation of cervical samples. Furthermore, immunohistochemical studies may be helpful in differentiating significant preneoplastic changes from other cervical lesions, such as atrophy.

Expression of the high mobility group proteins HMGI(Y) correlates with malignant progression in Barrett's metaplasia.

Expression of the high mobility group proteins HMGI(Y) has been shown to be a marker of malignancy in thyroid and pancreatic lesions and to correlate significantly with malignant progression in the colon. The aim of this study was to determine whether HMGI(Y) expression is associated with malignant progression in Barrett's metaplasia (BM). Immunoperoxidase staining for HMGI(Y) was performed on sections of formalin-fixed paraffin-embedded endoscopic esophageal biopsies from 42 patients with BM. These consisted of 19 biopsies negative for dysplasia (ND), 16 with low-grade dysplasia (LGD)/indeterminate for dysplasia (IND), and 7 with high-grade dysplasia (HGD)/adenocarcinoma (CA). The percentage of positive cells was recorded, and nuclear HMGI(Y) immunoreactivity in >10% of the cells was considered positive. Statistical analysis was performed using Fisher's exact test. Positive HMGI(Y) staining was detected in 2 of 19 (11%) cases ND, 5 of 16 (30%) LGD/IND cases, and 7 of 7 (100%) HGD/CA cases. Biopsies with HGD/CA were significantly more likely to be positive for HMGI(Y) than biopsies ND (P < 0.0001) or with LGD/IND (P = 0.0046). We conclude that HMGI(Y) expression is significantly associated with malignant progression in BM. Additional studies are needed to determine whether BM biopsies that are ND or LGD/IND and positive for HMGI(Y) are more likely to progress to adenocarcinoma.

Differential expression of estrogen receptor beta isoforms in human breast cancer tissue.

Five isoforms of estrogen receptor beta (ER-B) have been cloned, and were shown to have different amino acid sequences at their ligand binding domains. The aim of this study was to determine the protein expression of ER-B isoforms in human breast cancer tissues. Sections of formalin-fixed and paraffin-embedded tissue from 17 invasive breast carcinomas were immunostained for ER-B1, 2, 3 and 5 using affinity purified antibodies and the immunoperoxidase technique. ER-B1, 2, 3 and 5 expression in cancer cells was variable, with both nuclear and cytoplasmic staining seen. ER-B1 and ER-B2 were the most commonly expressed, whereas ER-B3 was uncommon. ER-B3 and ER-B5 expression was associated with larger tumor size and higher proliferative activity, but only ER-B3 expression was associated with lymph node metastasis. ER-B1, 2 and 5 were detected in normal epithelial cells; ER-B1 and 2 in endothelial, stromal, and myoepithelial cells; and ER-B2 in nerves. Our findings show that ER-B isoforms are differentially expressed in breast cancer cells and in benign epithelial and non-epithelial components of breast tissue, and suggest that ER-B isoform specific agonists and antagonists are likely to have different biological effects on normal and cancerous cells and tissues.