Metallothionein isoform II expression in hyperplastic, dysplastic and neoplastic prostatic lesions

Abstract

Background: Metallothionein is a low-molecular-weight cysteine-rich protein that has the ability to bind and sequestrate heavy metal ions. It is associated with metalloregulatory functions such as cell proliferation, growth and differentiation. Aims: To investigate the expression of metallothionein in hyperplastic, dysplastic and neoplastic prostatic lesions and to correlate its expression with histological grade of prostatic carcinoma. Method: The study was carried out on formalin-fixed and paraffin-wax-embedded tissue blocks from 8 patients with benign prostatic hyperplasia, 6 patients with prostatic intraepithelial neoplasia (PIN) and 30 patients with prostatic carcinoma, using the streptavidin-biotin technique. The histological grade was defined and the carcinomas were divided into low-grade (Gleason Score 2-4), 12 moderate grade (Gleason Score 5-6) and 10 high-grade (Gleason Score 7-10) carcinomas. Results: Patchy metallothionein staining of epithelial cells was observed in normal and benign prostatic tissues. All cases of PIN and 20 of 30 patients with prostatic carcinoma showed positive staining for metallothionein. Metallothionein expression considerably increased from low-grade to high-grade tumours. The proportion of cells staining positively for metallothionein was directly correlated with histological grade of prostatic carcinoma. The epithelial cells lack uniformity in staining intensity, but the percentage of strongly positive cells increased with the histological grade of prostatic carcinoma. Conclusions: The high incidence of metallothionein expression in PIN in our study suggests that it is associated with early prostate tumorigenesis. Also, metallothionein expression was directly correlated with the histological grade of prostatic carcinoma, suggesting that metallothionein may be a useful marker for predicting the prognosis of prostate cancer.

Metallothionein – Immunohistochemical Cancer Biomarker: A Meta-Analysis

“…Four studies were included in total [67], [121]–[123]. Athanassiadou and Moussa used Gleason scale as a measure of tumor grading.…”

Differential expression of metallothioneins (MTs) 1, 2, and 3 in response to zinc treatment in human prostate normal and malignant cells and tissues

“…At the present time, only few studies provided limited information of MT1/2 expression in human prostate tissues. Among these data, the correlation of the positive IHC staining of MT1/2 and the adenocarcinoma status was variable ranging from 33% (15/45) [ 30 ], 67% (20/30) [ 31 ] to 100% (5/5) [ 32 ]; while some reports indicated that the Gleason grades of the tumor tissue scoring from low to high reversely corresponded to the intensity of MT1/2 IHC staining [ 32 , 33 ].…”

Metallothioneins and zinc in cancer diagnosis and therapy

“…MT can also serve as a serum tumor marker in prostate cancer Masarik et al, 2011), head and neck tumors , childhood solid tumors , and melanoma . Expression of MT may help to distinguish between benign and malignant tumor, as shown in thyroid tumors (Krolicka et al, 2010), prostatic lesions (El Sharkawy et al, 2006), GI stromal tumors, and gastric carcinomas (Soo et al, 2011). At isoform levels, MT expression in breast and prostate cancers, renal tumors, and papillary thyroid cancer was reviewed by Thirumoorthy et al, who found that expression of MT Drug Metabolism Reviews Downloaded from informahealthcare.com by University of Sussex Library on 10/17/12…”