Study assessing the quality of quantification of estrogen receptor protein expression by immunohistochemistry and gene expression in breast cancer

In Vivo Quantitation of Estrogen Receptor β Subtype Expression in Ovarian Surface Epithelium Using Immunofluorescence Profiling and Confocal Microscopy

Immunohistochemistry using formalin-fixed, paraffin-embedded tissue, chromogen label, and light microscopy has traditionally been used to semiquantify estrogen receptor (ER) to guide diagnosis and management of breast cancer. Quantitation of ER for this purpose currently only assesses levels of the ER-alpha subtype. Considerable variability in results reported has been due to protocol and fixation variability, intraobserver and interobserver variability, and different scoring systems and thresholds for scoring ER positivity. Results can also vary with low expression levels of ER. ER-beta expression is reduced in breast and ovarian cancers and requires quantitation.Herein we describe a novel approach to quantifying ERβ using older mouse ovarian surface epithelium, where ERβ is expressed at lower levels than ERα and is therefore harder to detect. We use an antibody highly specific to the ERβ1 isoform, together with immunofluorescence, confocal microscopy, and imaging and statistical software to achieve clear, reproducible, and unbiased quantitation of ERβ.

From fix to fit into the autoptic human brains

Formalin-fixed, paraffinembedded (FFPE) human brain tissues are very often stored in formalin for long time. Formalin fixation reduces immunostaining, and the DNA/RNA extraction from FFPE brain tissue becomes suboptimal. At present, there are different protocols of fixation and several procedures and kits to extract DNA/RNA from paraffin embedding tissue, but a gold standard protocol remains distant. In this study, we analyzed four types of fixation systems and compared histo and immuno-staining. Based on our results, we propose a modified method of combined fixation in formalin and formic acid for the autoptic adult brain to obtain easy, fast, safe and efficient immunolabelling of long-stored FFPE tissue. In particular, we have achieved an improved preservation of cellular morphology and obtained success in postmortem immunostaining for NeuN. This nuclear antigen is an important marker for mapping neurons, for example, to evaluate the histopathology of temporal lobe epilepsy or to draw the topography of cardiorespiratory brainstem nuclei in sudden infant death syndrome (SIDS). However, NeuN staining is frequently faint or lost in postmortem human brain tissues. In addition, we attained Fluoro Jade C staining, a marker of neurodegeneration, and immunofluorescent staining for stem cell antigens in the postnatal human brain, utilizing custom fit fixation procedures.

High expression of heat shock protein 10 correlates negatively with estrogen/progesterone receptor status and predicts poor prognosis in invasive ductal breast carcinoma

Heat shock proteins (HSPs) usually are associated with stress response and tolerance. HSP10 is a co-chaperone for HSP60, which is involved in the mitochondrial protein-folding machinery. To the best of our knowledge, the expression of HSP10 in invasive ductal breast carcinoma (IDBC) has never been reported. In the present study, HSP10 expression in 242 cases of IDBC and 46 cases of noncancerous breast tissues was detected by immunohistochemistry staining. High expression was significantly more common in IDBC than in noncancerous breast tissues (P<.001). Also, high expression was significantly more common in poorly differentiated than in well- and moderately differentiated IDBC (P=.023). Furthermore, high expression correlated negatively with estrogen receptor and progesterone receptor expression (P=.031 and P=.042, respectively). The most interesting result of the study was that high expression of HSP10 was significantly associated with shorter overall survival by both univariate and multivariate analyses (P=.013 and P=.036, respectively). In conclusion, we report for the first time that high expression of HSP10 is negatively associated with estrogen receptor/progesterone receptor status and might be a novel independent biomarker for poor prognosis in IDBC.

Association between the ornithine decarboxylase G316A polymorphism and breast cancer survival

Ornithine decarboxylase (ODC) is a significant rate-limiting enzyme in polyamine synthesis, required for normal cell growth, and is highly expressed in various malignancies, including colorectal and breast cancer. In the present study, the associations between the ODC G316A single nucleotide polymorphism (SNP) and breast cancer-specific survival were investigated. In addition, the functional effects of this SNP were examined in the MCF-7 human breast cancer cell line. The present study recruited 300 stage I-III breast cancer cases, which were diagnosed at the Affiliated Cancer Hospital of Zhengzhou University (Zhengzhou, China) between 2002 and 2003, with follow-up visits conducted until May 2013. ODC G316A was genotyped (ODC GG vs. ODC AG/AA) in the 300 cases and the association of the genotypes with cancer-specific survival was analyzed. In the MCF-7 cell line, the ODC allele-specific binding of E-box transcription factors was determined using western blot and chromatin immunoprecipitation assays. Survival differences were observed between the two genotypes: Compared with the ODC GG genotype, patients with ODC GA/AA exhibited significantly higher survival rates (P<0.05). In cultured cells, the ODC SNP, which is flanked by two E-boxes, appeared to predict ODC promoter activity. Furthermore, the E-box activator c-MYC and repressor MAX interactor 1 were found to preferentially bind to ODC minor A-alleles compared with major G-alleles, in cultured MCF-7 cells. In conclusion, the results of the current study suggest that the regulation of ODC may affect survival in breast cancer patients and indicate a model in which the ODC SNP may be protective for breast adenoma recurrence and detrimental for survival following a diagnosis of breast cancer.