S. Ashraf Imam

Strategies for improving the immunohistochemical staining of various intranuclear prognostic markers in formalin-paraffin sections: Androgen receptor, estrogen receptor, progesterone receptor, p53 protein, proliferating cell nuclear antigen, and Ki-67 antigen revealed by antigen retrieval techniques

Different variations of the antigen retrieval technique using different retrieval solutions have been evaluated for their effectiveness in restoring the antigenicity of six intranuclear antigens, each of which is a potentially valuable prognostic indicator in formalin-fixed, paraffin-embedded tissue sections. The results of immunohistochemical staining for estrogen receptor, progesterone receptor, androgen receptor, p53 protein, proliferating cell nuclear antigen, and Ki-67 antigen were compared following the different antigen retrieval approaches. The strongest immunostaining signal with the clearest background was obtained by microwave heating of dewaxed paraffin sections for 10 minutes in 0.05 mol/L glycine HCl (pH 3.5) or in citrate buffer solution (pH 6). Urea solution, distilled water, and lead thiocyanate solution yielded improvements with some antigens, but less consistently and less impressively than glycine HCl buffer or citrate buffer. Following antigen retrieval nuclear staining was sharply defined and could be achieved consistently in a variety of tissues after formalin fixation for as long as 7 days. The duration of fixation, however, was an important variable; generally, the longer the fixation time the more vigorous the retrieval procedure required. This study demonstrates the ability to stain a variety of intranuclear antigens, which are not readily demonstrable otherwise, in formalin-paraffin sections with a high degree of consistency and reproducibility. The availability of methods that are effective in paraffin sections may facilitate studies of the possible value of these markers as prognostic indicators for predicting the response of major tumors to different forms of therapy. This study also provided insight into the basic principles of the antigen retrieval method, which may be helpful in attempts to develop a more uniformly standardized technique applicable to many different antigen systems.

Human Breast Cancer Histoid An In Vitro 3-Dimensional Co-culture Model That Mimics Breast Cancer Tissue

Progress in our understanding of heterotypic cellular interaction in the tumor microenvironment, which is recognized to play major roles in cancer progression, has been hampered due to unavailability of an appropriate in vitro co-culture model. The aim of this study was to generate an in vitro 3-dimensional human breast cancer model, which consists of cancer cells and fibroblasts. Breast cancer cells (UACC-893) and fibroblasts at various densities were co-cultured in a rotating suspension culture system to establish co-culture parameters. Subsequently, UACC-893, BT.20, or MDA.MB.453 were co-cultured with fibroblasts for 9 days. Co-cultures resulted in the generation of breast cancer histoid (BCH) with cancer cells showing the invasion of fibroblast spheroids, which were visualized by immunohistochemical (IHC) staining of sections (4 µm thick) of BCH. A reproducible quantitative expression of C-erbB.2 was detected in UACC-893 cancer cells in BCH sections by IHC staining and the Automated Cellular Imaging System. BCH sections also consistently exhibited qualitative expression of pancytokeratins, p53, Ki-67, or E-cadherin in cancer cells and that of vimentin or GSTPi in fibroblasts, fibronectin in the basement membrane and collagen IV in the extracellular matrix. The expression of the protein analytes and cellular architecture of BCH were markedly similar to those of breast cancer tissue.

Unmethylated E‐Cadherin gene expression is significantly associated with metastatic human prostate cancer cells in bone

The concurrent determination of methylation status of E‐cadherin gene and E‐cadherin protein expression remains scant in metastatic prostate cancer cells in bone, the most prevalent site for metastatic growth. Therefore, the study was undertaken to ascertain the methylation status of E‐cadherin gene, a most frequent and known epigenetic mechanism of its regulation, and the protein expression in prostate tissue biopsy specimen.

Telomerase and markers of cellular proliferation are associated with the progression of cervical intraepithelial neoplasia lesions.

Summary: The expression of the catalytic subunit of telomerase protein (human telomerase reverse transcriptase [hTERT]), which is associated with telomerase activity, was evaluated as a potential marker of the high-grade premalignant cervical intraepithelial neoplasia (CIN 2/3) lesions. For comparison, cases of normal cervical squamous mucosa, low-grade CIN1 lesion, and cervical squamous cell carcinoma were included. The hTERT expression was also compared with Ki-67 and topoisomerase II-&agr; (TPII-&agr;) to determine the proliferative activity of the hTERT-positive dysplastic cells by a quantitative immunohistochemical staining method and was classified as follows: negative, 5% or less; moderate, 6% to 50%; or high, greater than 50% of the positive cells. The hTERT-positive cells were detected in a patchy pattern in the lower parabasal layers and in much of the basal layer in normal squamous mucosa. A similar frequency of Ki-67- or TPII-&agr;-positive cells was observed, with the exception of the basal layer cells that were mostly negative. It is worthy to note that the recognizable intact basal layer cells in cases of CIN lesions were also consistently positive for the expression of hTERT, but rarely for Ki-67 or TPII-&agr;. The expression of hTERT was detected in a less patchy pattern at a high or moderate percentage of the dysplastic epithelial cells each in 28.5% of cases of CIN1 lesions. A similar frequency, high and moderate percentage combined, of the TPII-&agr;-positive dysplastic cell was also observed. In contrast, a high percentage of the hTERT-positive dysplastic cells were detected as diffuse basal or full-length thickness in 87.5% or 95% of cases of CIN2 or CIN3, respectively. A similar frequency of Ki-67 or TPII-&agr; expression was observed in the dysplastic cells of CIN3 lesions. The pattern of hTERT-positive malignant cells in squamous cell carcinoma and dysplastic cells in the high-grade CIN lesions, to a greater extent, and dysplastic cells in the low-grade CIN lesion, to a lesser extent, was distinct from that of the normal cervical squamous mucosa. The results suggest that the progressive increase in the hTERT expression, together with the proliferative activity of the dysplastic epithelial cells of the high-grade CIN lesions, represents an early genetic abnormality in cervical pathogenesis.

Telomeric DNA : Marker for human prostate cancer development?

Telomeres that protect chromosomes at both ends are shortened with each somatic cell division through replication‐dependent sequence loss at DNA termini. The chromosomes with shortened telomeres tend to become unstable, leading to cell death. Due largely to reactivation/upregulation of telomerase, a ribonucleoprotein that adds nucleotide sequences onto chromosome ends, cancer cells become immortal and neoplastically transformed.

Telomerase activity: comparison between fine-needle aspiration and biopsy specimens for the detection of tumor cells.

The purpose of the current study was to determine telomerase activity as a sensitive biomarker for the detection of malignant cells in fine‐needle aspiration (FNA) specimens.

LEA.135 expression: an independent and favorable prognostic biomarker for patients with primary invasive breast cancer.

The prognostic significance of LEA.135 expression, detected by immunohistochemistry in formalin‐fixed and paraffin‐embedded tissue sections, was evaluated and compared with the widely utilized clinicopathological parameters for patients with primary invasive breast carcinomas. Pathological parameters such as tumor size, histological tumor type, histological grade, nuclear grade, lymph node (LN) status, bone marrow (BM) status, as well as age of patient at initial diagnosis together with follow‐up in years were available for this group of patients (n = 178). Among these parameters, tumor size, histological tumor type, histological grade, LN status, and BM status were individually and significantly associated with increased probability of recurrence by univariate analysis. By multivariate analysis, however, only tumor size, LN status, and BM status remained statistically significant. LEA.135‐positive patients showed a statistically significant probability of not recurring (77 ± 5% at 5 years after surgery) compared with patients who were LEA.135‐negative (49 ± 6% at 5 years after surgery) (log‐rank p < 0.001). Furthermore, the association remained statistically significant by multivariate analysis (log‐rank p = 0.019), demonstrating that LEA.135 expression independently and significantly identified breast cancer patients with favorable clinical outcome. In addition, there was a statistically significant association between loss of LEA.135 expression and poor prognosis when patients were stratified by pathological parameters. Furthermore, a subgroup of patients who were LEA.135‐positive/LN‐negative experienced a decreased rate of recurrence compared with those who were LEA.135‐negative/LN‐negative (16% vs. 27%, respectively). A similar result was also obtained when BM‐negative patients were stratified on the basis of LEA.135‐positive or LEA.135‐negative subgroups for recurrence (18% vs. 43%, respectively). Most interestingly, the patients whose cancer cells were LEA.135‐positive/LN‐positive experienced a much lower rate of recurrence than those whose cells were LEA.135‐negative/LN‐positive (29% vs. 57%, respectively). The results clearly demonstrate that LEA.135 expression was a significantly independent and favorable prognostic marker for patients with primary invasive breast carcinoma by both univariate and multivariate analyses. Int. J. Cancer 89:224–229, 2000.

J1‐31 protein expression in astrocytes and astrocytomas

J1‐31 is one of the astrocytic proteins, the expression of which has not been evaluated in astrocytomas. In the present study, we studied the expression of J1‐31 protein in astrocytes and astrocytomas in comparison with GFAP, p53 and Ki‐67. Materials consisted of formalin‐fixed paraffin‐embedded tissue specimens that included five cases of normal brain, 17 of gliosis, 15 of pilocytic astrocytoma (WHO grade I), 26 of low‐grade diffuse astrocytoma (WHO grade II), four of anaplastic astrocytoma (WHO grade III), and eight of glioblastoma (WHO grade IV). GFAP was highly expressed in all specimens examined. The anti‐J1‐31 antibody exhibited strong cytoplasmic staining of reactive gliosis in 17/17 (100%) cases with a higher intensity of staining than that observed in the adjacent normal astrocytes. The antibody showed reactivity with tumor cells in 12/15 (80%) cases of pilocytic astrocytoma, although intensity of staining was generally weaker and more focal than observed in reactive gliosis. J1‐31‐positive tumor cells were detected in only 9/26 (35%) cases of the low‐grade diffuse astrocytoma and none of the cases of anaplastic astrocytoma and glioblastoma. Increasing Ki‐67 indices paralleled advancing tumor grades. p53 protein was expressed more commonly in infiltrating astrocytomas compared to pilocytic astrocytoma. In conclusion, down‐regulation of J1‐31 expression correlates with advancing grade of astrocytomas. The result suggests this protein plays some role in astrocytes that is progressively lost in malignant progression. The anti‐J1‐31 antibody may help further our understanding of astrocytes in disease and may be useful as an aid in the pathologic diagnosis of astrocytic lesions.

Down-Regulation of a Cell-Surface Glycoprotein Correlated with Rearrangement of Chromosome 1 in Human Breast Cancer Cells

The loss of heterozygosity of genes on chromosome 1q, 11p, 13q and 17p in human breast cancer cells has been reported [1–5]. However, reduction to homo- or hemizygosity has not been identified at a molecular level. In the current study, an attempt was made to identify any normal genes that may become inactivated in malignant cells, with associated loss of the gene products.