Schostak M, Krause H, Miller K, Schrader M, Weikert S, Christoph F, Kempkensteffen C, Kollermann J
Department of Urology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Germany.
BMC Urol. 2006 Mar 15;6:7. doi: 10.1186/1471-2490-6-7.
Gene expression profiling has recently shown that the mRNA for CD24 is overexpressed in prostate carcinomas (Pca) compared to benign or normal prostate epithelial tissues. Immunohistochemical studies have reported the usefulness of anti-CD24 for detecting prostate cancer over the full range of prostate specimens encountered in surgical pathology, e.g. needle biopsies, transurethral resection of prostate chips, or prostatectomies. It is a small mucin-like cell surface protein and thus promises to become at least a standard adjunctive stain for atypical prostate biopsies. We tested the usefulness of real-time RT-PCR for specific and sensitive detection of CD24 transcripts as a supplementary measure for discriminating between malignant and benign lesions in prostatic tissues.
Total RNA was isolated from snap-frozen chips in 55 cases of benign prostatic hyperplasia (BPH) and from frozen sections in 59 prostatectomy cases. The latter contain at least 50% malignant epithelia. Relative quantification of CD24 transcripts was performed on the LightCycler instrument using hybridization probes for detection and porphobilinogen deaminase transcripts (PBGD) for normalization.
Normalized CD24 transcript levels showed an average 2.69-fold increase in 59 Pca-cases (mean 0.21) when compared to 55 cases of BPH (mean 0.08). This difference was highly significant (p < 0.0001). The method has a moderate specificity (47.3%) but a high sensitivity (86.4%) if the cutoff is set at 0.0498. CD24 expression levels among Pca cases were not statistically associated with the tumor and lymph-node stage, the grading (WHO), the surgical margins, or the Gleason score.
The present study demonstrates the feasibility of quantitative CD24 RNA transcript detection in prostatic tissues even without previous laser microdissection.
基因表达谱分析最近显示，与良性或正常前列腺上皮组织相比，CD24的mRNA在前列腺癌（Pca）中过表达。免疫组织化学研究报告称，抗CD24在手术病理学中遇到的全范围前列腺标本（如针吸活检、经尿道前列腺组织切除或前列腺切除术）中检测前列腺癌很有用。它是一种小的粘蛋白样细胞表面蛋白，因此有望至少成为非典型前列腺活检的标准辅助染色剂。我们测试了实时逆转录聚合酶链反应（RT-PCR）用于特异性和灵敏地检测CD24转录本作为区分前列腺组织中恶性和良性病变的补充措施的实用性。
从55例良性前列腺增生（BPH）的速冻组织芯片以及59例前列腺切除病例的冰冻切片中分离总RNA。后者至少含有50%的恶性上皮细胞。使用杂交探针进行检测，并以胆色素原脱氨酶转录本（PBGD）进行标准化，在LightCycler仪器上对CD24转录本进行相对定量。
与55例BPH（平均0.08）相比，59例Pca病例（平均0.21）中标准化的CD24转录本水平平均增加了2.69倍。这种差异具有高度统计学意义（p < 0.0001）。如果将临界值设定为0.0498，该方法具有中等特异性（47.3%）但高灵敏度（86.4%）。Pca病例中的CD24表达水平与肿瘤和淋巴结分期、分级（世界卫生组织）手术切缘或Gleason评分无统计学关联。
本研究证明了即使不进行先前的激光显微切割，在前列腺组织中定量检测CD24 RNA转录本的可行性。
