Gyftopoulos K, Perimenis P, Sotiropoulou-Bonikou G, Sakellaropoulos G, Varakis I, Barbalias G A
Department of Urology, School of Medicine, University of Patras, Greece.
Int Urol Nephrol. 2000;32(2):263-9. doi: 10.1023/a:1007126332651.
The use of retinoids as differentiation therapy is a novel approach to prostate cancer. Retinoids act via their own nuclear receptors, RARs and RXRs, modulating gene activity, cell growth and differentiation. This study provides new data on the content and cellular distribution of RARalpha protein in prostate cancer specimens, in correlation to tumor grade and proliferative activity.
A total of 84 cases of primary prostate carcinoma, divided into 3 subgroups according to tumor grade, were immunohistochemically evaluated for retinoic acid receptor-alpha (RARalpha) and Ki67 using the streptavidin/peroxidase method on formalin fixed, paraffin embedded tissues.
RARalpha positivity was detected in all cases of prostatic carcinoma, with a more profound expression in well differentiated cancers. A statistically significant correlation between RARalpha staining and tumor grade was found (ANOVA, p < 0.031). Ki67 immunoreactivity was present in 35.7% of cases, but no correlation with tumor grade was found. When RARalpha staining was correlated with Ki67 positivity, a statistically significant correlation was present (unpaired t-test, p < 0.003).
These findings indicate that RARalpha expression is correlated to some extent with tumor grade and its presence is more profound in highly proliferative tumors. Further studies are needed to establish the possible clinical value of the immunohistochemical evaluation of RARalpha content in tumor specimens.
使用维甲酸进行分化治疗是前列腺癌治疗的一种新方法。维甲酸通过其自身的核受体RARs和RXRs发挥作用，调节基因活性、细胞生长和分化。本研究提供了前列腺癌标本中RARα蛋白含量和细胞分布的新数据，并与肿瘤分级和增殖活性相关联。
总共84例原发性前列腺癌，根据肿瘤分级分为3个亚组，采用链霉亲和素/过氧化物酶法，对福尔马林固定、石蜡包埋组织中的维甲酸受体α（RARα）和Ki67进行免疫组织化学评估。
在所有前列腺癌病例中均检测到RARα阳性，在高分化癌中表达更为明显。发现RARα染色与肿瘤分级之间存在统计学显著相关性（方差分析，p < 0.031）。35.7%的病例存在Ki67免疫反应性，但未发现与肿瘤分级相关。当RARα染色与Ki67阳性相关时，存在统计学显著相关性（非配对t检验，p < 0.003）。
这些发现表明，RARα表达在一定程度上与肿瘤分级相关，且在高增殖性肿瘤中其表达更为明显。需要进一步研究以确定肿瘤标本中RARα含量免疫组织化学评估的可能临床价值。
