張瑩 王希喆 周露 丁粉干
[摘要] 目的 研究α甲?;o酶A消旋酶(p504s)、細胞角蛋白5/6(ck5/6)和p63在前列腺增生和前列腺癌中的診斷價值。 方法 采用免疫組織化學染色法檢測江蘇省無錫市惠山區(qū)人民醫(yī)院及江蘇省無錫市錫山人民醫(yī)院病理科2012年1月~2017年12月收集的120例前列腺穿刺活檢樣本中p504s、ck5/6和p63的表達情況,其中前列腺癌70例(前列腺癌組)、前列腺增生50例(前列腺增生組)。將65例前列腺腺泡細胞癌按照Gleason分級標準分為≤6分組(20例)、7~8分組(26例)和≥9分組(19例)三個亞組。根據(jù)染色強度、陽性細胞百分數(shù)的乘積結果作為結果來進行比較。采用SPSS 15.0統(tǒng)計軟件對結果進行統(tǒng)計學分析。 結果 前列腺癌組中p504s表達率為91.43%,其中64.28%(45/70)為強陽性。前列腺增生組僅5例為p504s弱陽性表達,表達率為10.00%。ck5/6在前列腺癌組中表達陽性率為11.43%(8/70),且均為弱陽性;前列腺增生組90.00%(45/50)為ck5/6陽性表達,且84.00%(42/50)為中等強度以上陽性表達。p63在前列腺癌組中表達陽性率為8.57%(6/70),且均為弱陽性;前列腺增生組中92.00%(46/50)為p63陽性表達,且82.00%(41/50)為中等強度以上陽性表達。兩組p504s、ck5/6和p63表達情況比較,差異有統(tǒng)計學意義(P < 0.05)。Gleason分級≤6分組、7~8分組和≥9分組p504s表達強度差異有統(tǒng)計學意義(P < 0.05),其中7~8分組和≥9分組p504s表達強度顯著高于≤6分組(P < 0.05),但7~8分組和≥9分組的p504s表達強度差異無統(tǒng)計學意義(P > 0.05)。腺體部分性萎縮、腺體完全性萎縮和基底細胞增生三種類型的前列腺增生組織中ck5/6、p63表達強度差異均無統(tǒng)計學意義(P > 0.05)。腺體部分性萎縮和腺體完全性萎縮中各有3例和2例ck5/6表達缺失,均有2例p63表達缺失。 結論 p504s在前列腺癌組織中明顯高表達,而p63、ck5/6表達明顯降低,且p504s表達強度隨著Gleason分級的增高而增強,提示三者聯(lián)合檢測在前列腺癌和良性病變的診斷中有良好的應用價值。
[關鍵詞] 前列腺癌;前列腺增生;p504s;ck5/6;p63
[中圖分類號] R737.25 [文獻標識碼] A [文章編號] 1673-7210(2018)06(b)-0106-04
[Abstract] Objective To study the diagnostic value of alpha methylacyl coenzyme A racemase (p504s), cytokeratin5/6 (ck5/6) and p63 in benign prostatic hyperplasia (BPH) and prostate cancer. Methods Immunohistochemical staining method was used to detect the expression of p504s, ck5/6 and p63 in 120 cases of prostate biopsy specimens that collected in Department of Pathology, Huishan People's Hospital of Wuxi City and Xishan People′s Hospital of Wuxi City from January 2012 to December 2017. In the 120 cases, 70 cases were prostate cancer (prostate cancer group), 50 cases were BPH (BPH group). 65 cases of patients with prostate acinic cell carcinoma were divided into three subgroups according to the Gleason classification standard: ≤6 scores group (20 cases), 7-8 scores group (26 cases) and ≥9 scores group (19 cases). The product of staining intensity and percentage of positive cells was compared among these groups. Statistical software SPSS 15.0 was used to analyze the results. Results The expression rate of p504s in the prostate cancer group was 91.43%, 64.28% (45/70) were strongly positive. Only 5 cases of BPH group were p504s weakly positive, and the expression rate was 10.00%. The positive rate of ck5/6 expression in prostate cancer group was 11.43% (8/70), and all of them were weakly positive. 90.00% (45/50) of BPH group were ck5/6 positive expression, and 84.00% (42/50) were positive expression above medium intensity. The positive rate of p63 expression in prostate cancer group was 8.57% (6/70), and all of them were weakly positive. 92.00% (46/50) of BPH group were p63 positive, and 82.00% (41/50) were positive expression above medium intensity. There was a significant difference in the expression of p504s, ck5/6 and p63 in the two groups (P < 0.05). There was a significant difference in the expression intensity of p504s in ≤6 score group, 7-8 score group and ≥9 score group (P < 0.05). The expression intensity of p504s in 7-8 score group and ≥9 score group were significantly higher than that in ≤6 score group (P < 0.05). The expression intensity of p504s in 7-8 score group and ≥9 score group had no significant difference (P > 0.05). There was no significant difference in the expression intensity of ck5/6 and p63 among three types of benign prostatic hyperplasia tissues, which included partial atrophy of glands, complete atrophy of glands, and hyperplasia of basal cells (P > 0.05). There were 3 cases of ck5/6 deletion, and 2 cases of p63 expression deletion in the glandular partial atrophy. There were 2 cases of ck5/6 expression deletion, and 2 cases of p63 expression deletion in the complete atrophy of glands. Conclusion The expression of p504s is highly expressed in the prostate cancer tissue, while the expression of p63 and ck5/6 is decreased significantly. The expression intensity of p504s is enhanced with the degree increase of Gleason classification. It is suggested that the combined detection of p504s, ck5/6 and p63 has good application value in the diagnosis of prostate cancer and BPH.
[Key words] Prostate cancer; Benign prostatic hyperplasia; p504s; ck5/6; p63
前列腺癌是男性高發(fā)的惡性腫瘤之一,近幾年來我國男性前列腺癌發(fā)病率逐年升高,目前是僅次于膀胱癌、腎癌的第三大男性泌尿生殖系統(tǒng)惡性腫瘤[1]。早期診斷和治療是降低前列腺癌發(fā)生率和死亡率的重要手段,目前主要通過血清前列腺特異性抗原(PSA)、前列腺特異性膜抗原(PSMA)、前列腺干細胞抗原(PSCA)等血清學指標進行前列腺癌早期篩查,但均存在較高的假陽性和假陰性,造成誤診和漏診[2-3]。細針多點穿刺活檢是目前前列腺疾病最常采用的活檢技術,具有創(chuàng)傷小的優(yōu)點,但由于其取材較小,對于良性病變和腫瘤之間的病理診斷有一定的困難[4]。免疫組織化學染色法是病理科常用的病理診斷技術,已經(jīng)在前列腺癌診斷和鑒別診斷中廣泛應用。本研究通過免疫組織化學法檢測前列腺穿刺活檢樣本中的α甲酰基輔酶A消旋酶(p504s)、細胞角蛋白5/6(ck5/6)和p63,分析這三種抗體在前列腺良惡性病變診斷和鑒別診斷與分級中的臨床價值。
1 資料與方法
1.1 一般資料
以江蘇省無錫市惠山區(qū)人民醫(yī)院及江蘇省無錫市錫山人民醫(yī)院病理科于2012年1月~2017年12月收集的120例前列腺穿刺活檢樣本作為研究對象,其中前列腺癌70例(前列腺癌組)、前列腺增生50例(前列腺增生組)。前列腺癌組中,年齡42~72歲,平均(57.43±7.82)歲;其中腺泡細胞癌65例,泡沫細胞癌3例,導管癌1例,小細胞癌1例;將前列腺腺泡細胞癌按照Gleason評分標準分為≤6分組(20例)、7~8分組(26例)、≥9分組(19例)。前列腺增生組中,年齡40~70歲,平均(56.82±7.18)歲;伴腺體部分性萎縮15例,腺體完全性萎縮32例,基底細胞增生3例。兩組患者一般資料比較差異無統(tǒng)計學意義(P > 0.05),具有可比性。
1.2 研究方法
采用免疫組織化學法[5]檢測各樣本p504s、ck5/6和p63蛋白表達情況,實驗操作步驟嚴格按照試劑盒說明書進行。采用PBS緩沖液代替一抗作為陰性對照,已知抗體陽性標本作為陽性對照。染色結果判定標準:由病理醫(yī)師隨機抽取10個高倍鏡視野進行觀察,各抗體應表達于特定部位,p504s和ck5/6表達在細胞質中,p63表達定位于細胞核中,以特定部位出現(xiàn)明顯高于背景的棕黃色顆粒狀著色為陽性。計分標準:①染色強度:無著色計0分,淺黃色計1分,棕黃色計2分,棕褐色計3分;②陽性細胞百分數(shù):在400×顯微鏡下隨機選取10個視野計數(shù),各計數(shù)100個細胞,取10個視野的積分平均值作為最終分;無陽性細胞計0分,<11%計1分,11%~<51%計2分,51%~<75%計3分,≥75%計4分。以上述兩者乘積作為最后結果:0分為陰性(-),1~4分為弱陽性(+),5~8分為中等強度陽性(++),9~12分為強陽性(+++)。本研究所用小鼠抗人p504s單克隆抗體、小鼠抗人ck5/6單克隆抗體、小鼠抗人p63單克隆抗體、S-P免疫組化檢測試劑盒均購自福州邁新生物技術開發(fā)有限公司。所有免疫組化切片和HE染色切片均由2位病理醫(yī)師分別做出評定,評定結果不一致則由二人商議后做出最終判斷。
1.3 統(tǒng)計學方法
采用SPSS 15.0軟件進行統(tǒng)計學分析,計數(shù)資料比較采用χ2檢驗。等級資料用頻數(shù)表示,多組間比較采用Kruskal-Wallis檢驗,兩組間比較采用Mann-Whitney檢驗。以P < 0.05為差異有統(tǒng)計學意義。
2 結果
2.1 兩組p504s、ck5/6和p63的表達比較
p504s在前列腺癌活檢樣本中與癌性腺體特異性結合,呈現(xiàn)為高表達,表達率為91.43%,且45例(64.28%)為強陽性,前列腺增生組僅5例為p504s弱陽性,表達率為10.00%。ck5/6在前列腺癌活檢樣本中表達陽性率為11.43%;前列腺增生組45例(90.00%)為ck5/6陽性表達。p63在前列腺癌活檢樣本中表達陽性率為8.57%;前列腺增生組樣本中有46例(92.00%)為p63陽性表達。兩組p504s、ck5/6和p63表達情況比較,差異有統(tǒng)計學意義(P < 0.05)。見表1。
2.2 前列腺腺泡細胞癌分級與p504s表達強度的關系
將前列腺腺泡細胞癌根據(jù)Gleason分級分為≤6分、7~8分和≥9分三個亞組,三組p504s表達強度比較,差異有統(tǒng)計學意義(P < 0.05);其中Gleason分級7~8分組和≥9分組p504s表達強度顯著高于≤6分組(P < 0.05),但Gleason分級7~8分和≥9分兩組的p504s表達強度比較,差異無統(tǒng)計學意義(P > 0.05)。見表2。
2.3 前列腺增生與ck5/6和p63表達強度的關系
腺體部分性萎縮、腺體完全性萎縮和基底細胞增生三種類型的前列腺增生組織中的ck5/6、p63表達強度比較,差異無統(tǒng)計學意義(P > 0.05)。腺體部分性萎縮和腺體完全性萎縮中分別有3例和2例ck5/6表達缺失,均有2例p63表達缺失。見表3。
表3 前列腺增生與ck5/6和p63表達強度的關系(例)
3 討論
p504s屬于胞漿蛋白,主要存在于線粒體和過氧化物酶體中,參與脂肪酸和脂肪酸衍生物的β氧化過程[6]。2000年Xu等[7]通過基因芯片篩選確認p504s在前列腺癌組織中呈現(xiàn)高度表達,在正常前列腺組織中僅有少量表達或者無法檢出。除了前列腺癌外,p504s也在神經(jīng)系統(tǒng)、結腸、胃、胰腺等正常組織中表達,其過度表達往往預示癌前病變的發(fā)生[8-9]。p504s與其催化的支鏈脂肪酸氧化在前列腺癌的發(fā)生過程中發(fā)揮重要的作用[10]。植烷酸是一種存在于紅色肉類和奶制品中的常見支鏈脂肪酸,降植烷酸是植烷酸經(jīng)α-氧化途徑分解的主要產(chǎn)物,也是p504s的主要作用底物[11]。研究表明前列腺癌發(fā)病與患者細胞質中支鏈脂肪酸水平長期處于較高水平有關,植烷酸代謝產(chǎn)生降植烷酸,降植烷酸能夠激活過氧化物酶體增殖激活受體(peroxisome proliferator activated receptor,PPAR),而PPAR能夠控制細胞增殖和分化[12]。大量研究證實p504s在前列腺腫瘤組織中均過度表達,其基因序列的多態(tài)性與前列腺癌的發(fā)病風險密切相關[13-14]。本研究結果顯示,p504s在前列腺癌活檢樣本中與前列腺癌性腺體特異性結合,呈現(xiàn)出高表達,表達率為91.43%,前列腺增生組僅5例為p504s弱陽性,表達率為10.00%。Jiang等[15]針對4385例前列腺癌患者的Meta分析顯示,免疫組化p504s表達與前列腺癌的診斷顯著相關,但若將p504s作為前列腺癌早期診斷的標志物,則特異性較差,因此還需要聯(lián)合應用其他的指標進行前列腺癌診斷。另一方面,不同級別前列腺腺泡細胞癌組織中p504s表達情況稍有不同,Gleason分級7~8分和≥9分兩組p504s表達強度顯著高于Gleason分級≤6分組,提示p504s在前列腺癌進展中也發(fā)揮重要作用。
細胞角蛋白ck5/6是目前免疫組織化學染色法檢測中常用的一種基底細胞標志物,在正常組織中多為陽性表達,在腫瘤組織中則多為陰性[16-19]。本研究中,ck5/6在前列腺癌活檢樣本中表達陽性率為11.43%(8/70),且均為弱陽性;前列腺增生組90.00%(45/50)為ck5/6陽性表達,且84.00%(42/50)為中等強度以上陽性表達。p63是p53抑癌基因家族中的一員,表達于前列腺基底細胞的細胞核上,特異性較強,且著色較為穩(wěn)定,是用于鑒別前列腺正常組織、良性病變和前列腺癌的重要指標[20-21]。本研究中p63在前列腺癌活檢樣本中表達陽性率為8.57%(6/70),且均為弱陽性;前列腺增生組樣本中有92.00%(46/50)為p63陽性表達,且82.00%(41/50)為中等強度以上陽性表達。提示ck5/6和p63在少部分前列腺良性病變中仍有可能發(fā)生缺失,因此不能將ck5/6或者p63單獨作為區(qū)別前列腺良性病變和前列腺癌的依據(jù)。
目前,多數(shù)學者聯(lián)合采用多種指標用于前列腺癌的鑒別和診斷,p504s表達上調、ck5/6和p63表達下調能夠從正、反兩個方面對是否發(fā)生前列腺癌進行判斷,具有較高的臨床應用價值。
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