生育酚结合蛋白在前列腺癌组织的表达及意义

The expression and significance of alpha-tocopherol associated protein in human prostate cancer

目的探讨生育酚结合蛋白(α-TAP)在良恶性前列腺组织的表达差异及意义。方法构建TAP-N端的质粒并转化到大肠杆菌BL21-Condon Plus,以1 mmol/L IPTG诱导3 h表达蛋白,用Ni-NTA琼脂糖柱纯化TAP蛋白并免疫兔生产抗体。将pGEM-T-easy质粒酶切线性化,37℃体外转录120 min合成地高辛标记的TAP-RNA探针。免疫组织化学和原位杂交法测定TAP在分别40例良性前列腺增生(BPH)与前列腺癌(PCa)的表达。结果制备到毫克量的TAP-N端蛋白、特异性TAP抗体和RNA探针。TAP主要表达于前列腺上皮,很少位于基质成分。BPH组TAP表达阳性率(37例,92．5%)比PCa组高(7例,17．5%),两组差异有统计学意义(P＜0．05)。无TAP表达的33例PCa患者术前PSA水平(12．5±3．3)μg/L、Gleason评分(7．3±1．4)分均高于其余7例TAP阳性患者(P＜0．05),后者PSA为(6．7±2．6)μg/L、Gleason评分为(4．6±2．1)分。TAP阴性的PCa患者术后出现复发时间(32．5±6．2)个月小于TAP阳性患者(78．5±12．6)个月(P＜0．05)。结论TAP在前列腺癌的表达比在良性前列腺增生组织明显下调,无TAP表达的前列腺癌患者术前PSA和Gleason评分高于TAP阳性患者。

Objective To investigate the expression and significance of alpha-tocopherol associated protein （TAP） in benign and malignant prostate tissues. Methods The plasmid pET-28a-TAP-N was constructed to express the N-terminal domains of TAP, and was transformed into E coil BL21-Condon Plus,induced by 1 mmol/L IPTG for 3 h. The recombinants were purified on Ni-NTA resin column and immunued in the rabbit to produce the antibody. The Digoxin-labeled RNA probe of TAP was in vitro transcripted using pGEM-T-easy. Immunohistochemistry staining and in situ hybridization were performed on 40 cases of benign prostatic hyperplasia （BPH） and 40 cases of prostate cancer （PCa）. Results The protein of TAP-N fragment was purified and the TAP antibody was produced successfully. TAP mainly expressed in the epithelium,not in the stroma. The positive rate of TAP in the BPH group （37 cases,92.5 % ） was higher than in the PCa group （ 7 cases, 17.5 % ） （P 〈 0.05 ）. Average preoperative PSA levels （12.5 ± 3.3） μg/L and Gleason scores （7.3 ± 1.4） in the 33 TAP negative PCa patients were higher than other TAP-positive patients as （6.7 ± 2.6） μg/L and 4.6± 2.1 scores, respectively （P 〈 0.05 ）. The survival time in the TAP-negative PCa patients （32.5 ± 6.2） months were shorter than the TAP-positive patients （78.5 ± 12.6） months. Conclusion The expression of TAP in prostate cancer was lower than in BPH tissues. Preoperative PSA levels and Gleason scores in the TAP-negative PCa patients were higher than in the TAP-positive patients.