許振,劉志強(qiáng),孟瑋,郭慶枝,孫莉
(濱州醫(yī)學(xué)院附屬醫(yī)院,山東濱州256600)
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宮頸癌組織中maspin、AKT、p-AKT表達(dá)變化及其與腫瘤微淋巴管密度的相關(guān)性
許振,劉志強(qiáng),孟瑋,郭慶枝,孫莉
(濱州醫(yī)學(xué)院附屬醫(yī)院,山東濱州256600)
目的 觀察宮頸癌組織中maspin、蛋白激酶B(AKT)、磷酸化蛋白激酶B(p-AKT)的表達(dá)變化,并分析其與腫瘤微淋巴管密度(LMVD)的相關(guān)性。方法 收集127例份宮頸石蠟組織標(biāo)本,其中慢性宮頸炎組織20例份(炎癥組)、CINⅠ級(jí)組織20例份(CIN1組)、CINⅡ級(jí)組織20例份(CIN2組)、CINⅢ級(jí)組織20例份(CIN3組)、宮頸癌組織47例份(宮頸癌組,其中無淋巴結(jié)轉(zhuǎn)移32例為宮頸癌1組、有淋巴結(jié)轉(zhuǎn)移15例為宮頸癌2組)。采用免疫組化SP法檢測各組maspin、AKT、P-AKT,測算腫瘤微淋巴管密度(LMVD)。結(jié)果 宮頸癌1組、宮頸癌2組maspin蛋白陽性表達(dá)比例低于其余各組(P均<0.05)。宮頸癌1組、宮頸癌2組AKT、p-AKT陽性表達(dá)比例高于其余三組(P均<0.05)。宮頸癌2組p-AKT陽性表達(dá)比例高于宮頸癌1組(P<0.05)。宮頸癌組織中maspin與AKT表達(dá)呈負(fù)相關(guān)關(guān)系(rs=-0.472,P=0.001),maspin與p-AKT表達(dá)也呈負(fù)相關(guān)關(guān)系(rs=-0.598,P=0.000)。宮頸癌1組、宮頸癌2組LMVD分別為(19.44±2.95)、(23.24±2.46)支/mm2,淋巴結(jié)轉(zhuǎn)移與LMVD呈正相關(guān)關(guān)系(rs=0.44,P=0.000)。宮頸癌組織中LMVD與maspin表達(dá)呈負(fù)相關(guān)關(guān)系(rs=-0.554,P=0.000),LMVD與p-AKT表達(dá)呈正相關(guān)關(guān)系(rs=0.39,P=0.007)。結(jié)論 宮頸癌組織中maspin表達(dá)下調(diào),AKT、p-AKT表達(dá)上調(diào),且maspin表達(dá)與AKT、p-AKT表達(dá)均呈負(fù)相關(guān)關(guān)系;宮頸癌組織中LMVD與maspin表達(dá)呈負(fù)相關(guān)關(guān)系,LMVD與p-AKT表達(dá)呈正相關(guān)關(guān)系。maspin表達(dá)下調(diào)可能參與了宮頸癌的發(fā)生發(fā)展,機(jī)制可能與AKT通路異常激活、促進(jìn)腫瘤微淋巴管生成有關(guān)。
宮頸癌;maspin基因;蛋白激酶B;微淋巴管密度
宮頸癌是最常見的女性生殖道惡性腫瘤之一,我國每年新發(fā)病例占世界宮頸癌新發(fā)病例總數(shù)的1/3,每年死于宮頸癌的患者約5萬人[1]。雖然手術(shù)、放療及化療的綜合治療已經(jīng)明顯改善了宮頸癌患者的預(yù)后,但對(duì)已經(jīng)發(fā)生淋巴結(jié)轉(zhuǎn)移的宮頸癌治療效果仍不太理想。淋巴結(jié)轉(zhuǎn)移是宮頸癌最常見、最重要的轉(zhuǎn)移途徑之一,也是影響患者預(yù)后的重要因素。maspin基因是絲氨酸蛋白酶抑制劑的一員,研究發(fā)現(xiàn)maspin對(duì)乳腺、前列腺等腫瘤的生長、侵襲、轉(zhuǎn)移有明顯抑制作用。maspin基因在宮頸鱗癌淋巴管生成及腫瘤轉(zhuǎn)移中的作用機(jī)制尚不清楚。近年來學(xué)者們通過對(duì)淋巴管標(biāo)志物及淋巴管生成因子進(jìn)行研究發(fā)現(xiàn),血管密度及微淋巴管密度(LMVD)是多種實(shí)體瘤預(yù)后的參考指標(biāo)之一[2,3]。磷脂酰肌醇-3激酶(PI3K)/絲蘇氨酸蛋白激酶(AKT)信號(hào)轉(zhuǎn)導(dǎo)通路是調(diào)控細(xì)胞增殖、維持細(xì)胞惡性生物學(xué)特性的重要轉(zhuǎn)導(dǎo)通路之一[4]。有研究[5]表明AKT通路在腫瘤淋巴管生成及淋巴結(jié)轉(zhuǎn)移中起著重要作用。本研究觀察了宮頸癌(鱗癌)組織中maspin、AKT、磷酸化AKT(p-AKT)的表達(dá)變化,并分析其與腫瘤LMVD的相關(guān)性。
1.1 組織標(biāo)本及主要試劑 2009年2月~2016年2月濱州醫(yī)學(xué)院附屬醫(yī)院婦產(chǎn)科宮頸活檢或手術(shù)中切取的宮頸石蠟組織標(biāo)本127例份,其中慢性宮頸炎組織20例份(炎癥組)、CINⅠ級(jí)組織20例份(CIN1組)、CINⅡ級(jí)組織20例份(CIN2組)、CINⅢ級(jí)組織20例份(CIN3組)、宮頸癌組織47例份(宮頸癌組,其中無淋巴結(jié)轉(zhuǎn)移32例為宮頸癌1組、有淋巴結(jié)轉(zhuǎn)移15例為宮頸癌2組)。炎癥組、CIN1組、CIN2組、CIN3組、宮頸癌組患者的年齡分別為(35.3±6.7)、(36.2±5.7)、(38.9±7.5)、(42.3±6.3)、(48.4±6.8)歲。各組標(biāo)本來源患者均無其他惡性腫瘤病史,獲取標(biāo)本前均未接受過放療及化療,均經(jīng)病理檢查證實(shí)診斷。兔抗人AKT單克隆抗體購自美國Cell Signaling公司。兔抗人p-AKT(Ser473)單克隆抗體購自美國Cell Signaling公司。即用型鼠抗人D2-40單克隆抗體購自北京中杉金橋生物技術(shù)有限公司。兔抗人maspin單克隆抗體購自北京博奧森生物技術(shù)有限公司。
1.2 不同宮頸病變組織中maspin、AKT、p-AKT檢測 將標(biāo)本進(jìn)行4 μm厚石蠟切片,免疫組化SP法染色,用PBS代替一抗作為陰性對(duì)照,用已知陽性片做陽性對(duì)照。maspin、AKT、p-AKT定位于細(xì)胞核與細(xì)胞質(zhì),以細(xì)胞核與細(xì)胞質(zhì)中出現(xiàn)棕黃色顆粒為陽性細(xì)胞。按照著色強(qiáng)度和陽性細(xì)胞百分比判定結(jié)果:著色強(qiáng)度為無色計(jì)0分、淺黃色計(jì)1分、黃色及更深顏色計(jì)2分,陽性細(xì)胞百分比≤50%計(jì)0分、>50%~75%計(jì)1分、>75%計(jì)2分[6];上述兩項(xiàng)得分相乘,≥2判定為目的蛋白表達(dá)陽性。
1.3 宮頸癌組織中LMVD觀察及計(jì)算方法 利用D2-40單克隆抗體標(biāo)記宮頸癌組織中的微淋巴管并計(jì)算LMVD。參考文獻(xiàn)[7]方法:D2-40表達(dá)定位于淋巴管內(nèi)皮細(xì)胞,呈棕黃色或棕褐色顆粒。先在40倍鏡下選擇4個(gè)微淋巴管高密度區(qū)即所謂的“熱點(diǎn)”,然后在400倍鏡視野(0.16 mm2/視野)下記數(shù),取4個(gè)視野的平均數(shù)(單位為支/mm2)。含有平滑肌或大于8個(gè)內(nèi)皮細(xì)胞的管腔及未染色的管腔不記數(shù)。
2.1 各組Maspin、AKT、p-AKT表達(dá)比較 宮頸癌1組、宮頸癌2組maspin蛋白陽性表達(dá)比例低于其余各組(P均<0.05)。宮頸癌1組、宮頸癌2組AKT、p-AKT陽性表達(dá)比例高于其余三組(P均<0.05)。宮頸癌2組p-AKT陽性表達(dá)比例高于宮頸癌1組(P<0.05)。詳見表1、圖1~3。
表1 各組maspin、AKT、p-AKT陽性表達(dá)情況(例)
注:A為炎癥組;B為CIN3組;C為宮頸癌組。
圖1 炎癥組、CIN3組、宮頸癌組中mapsin表達(dá)情況
注:A為炎癥組;B為CIN3組;C為宮頸癌組。
圖2 炎癥組、CIN3組、宮頸癌組中AKT表達(dá)情況
注:A為炎癥組;B為CIN3組;C為宮頸癌組。
圖3 炎癥組、CIN3組、宮頸癌組中p-AKT表達(dá)情況
2.2 宮頸癌組maspin、AKT、p-AKT表達(dá)的相關(guān)性 47例宮頸癌組織中maspin、AKT同時(shí)陽性表達(dá)的有0例、同時(shí)陰性表達(dá)的有3例,maspin與AKT表達(dá)呈負(fù)相關(guān)關(guān)系(rs=-0.472,P=0.001);宮頸癌組織中maspin、p-AKT同時(shí)陽性表達(dá)的有3例、同時(shí)陰性表達(dá)的有4例,maspin與p-AKT表達(dá)呈負(fù)相關(guān)關(guān)系(rs=-0.598,P=0.000)。
2.3 宮頸癌組LMVD表達(dá)變化及其與maspin、AKT、p-AKT表達(dá)的相關(guān)性 宮頸癌1組、宮頸癌2組LMVD分別為(19.44±2.95)、(23.24±2.46)支/mm2,淋巴結(jié)轉(zhuǎn)移與LMVD呈正相關(guān)關(guān)系(rs=0.44,P=0.000)。宮頸癌組中,maspin陽性組、maspin陰性組的LMVD分別為(17.45±2.88)、21.91±3.70)支/mm2,maspin陽性組LMVD低于maspin陰性組(P<0.05);AKT陽性組、AKT陽性組LMVD分別為(21.14±3.19)、(17.00±3.00)支/mm2,AKT陽性組LMVD高于AKT陰性組(P<0.05);p-AKT陽性組、p-AKT陽性組LMVD分別為(21.41±3.17)、(18.62±2.79)支/mm2,p-AKT陽性組LMVD高于p-AKT陰性組(P<0.05)。Spearman相關(guān)分析顯示,宮頸癌組織中LMVD與maspin表達(dá)呈負(fù)相關(guān)關(guān)系(rs=-0.554,P=0.000),LMVD與p-AKT表達(dá)呈正相關(guān)關(guān)系(rs=0.39,P=0.007)。
maspin基因是一種絲氨酸蛋白酶抑制劑基因,其不但對(duì)乳腺癌、前列腺癌等腫瘤的生長、侵襲、轉(zhuǎn)移有明顯抑制作用,而且能上調(diào)乳腺癌、前列腺癌細(xì)胞中凋亡前蛋白Bax的表達(dá),增強(qiáng)腫瘤細(xì)胞對(duì)凋亡誘導(dǎo)的敏感性[8]。Nam等[9]將含有maspin基因的質(zhì)粒注入植有NCIH157肺癌細(xì)胞株的裸鼠瘤體中,發(fā)現(xiàn)含有maspin基因質(zhì)粒的實(shí)驗(yàn)組成瘤體積遠(yuǎn)小于對(duì)照組,預(yù)示著maspin基因在腫瘤基因治療方面有著廣闊前景。本研究結(jié)果顯示,宮頸癌1組、宮頸癌2組maspin蛋白陽性表達(dá)比例低于CIN3組,提示maspin蛋白在宮頸CINⅢ發(fā)展到宮頸癌的過程中起著重要作用。大量臨床研究及動(dòng)物實(shí)驗(yàn)證實(shí)maspin基因表達(dá)具有抑制侵襲和遷移、抑制腫瘤血管生成的特性[10~12],maspin是一個(gè)多功能的抑癌基因。隨著腫瘤微淋巴管的相關(guān)研究不斷增多,有學(xué)者研究證實(shí)maspin基因可調(diào)節(jié)腫瘤微淋巴管的生成[13,14]。Wang等[13]發(fā)現(xiàn)在非小細(xì)胞肺癌患者中,maspin基因表達(dá)與VEGF-C表達(dá)呈負(fù)相關(guān),maspin基因表達(dá)與淋巴結(jié)轉(zhuǎn)移情況有關(guān)。但本研究中宮頸癌1組和宮頸癌2組的maspin陽性表達(dá)比例差異無統(tǒng)計(jì)學(xué)意義,考慮與樣本量較少有關(guān)。
PI3K/AKT通路在腫瘤細(xì)胞增殖、遷移、侵襲及抗凋亡中都起到舉足輕重的作用[4,15]。PI3K/AKT通路在腫瘤細(xì)胞G1期到S期轉(zhuǎn)變時(shí)變得非?;钴S,可以調(diào)節(jié)細(xì)胞周期調(diào)控關(guān)鍵因子P21CIP1、Cyclin D、p27Kip1的蛋白質(zhì)穩(wěn)定性[16]。PI3K/AKT通路分子高表達(dá)使得腫瘤細(xì)胞處于增殖活躍期并具有明顯的抗凋亡作用。有研究[17]顯示人乳頭瘤病毒16(HPV16)分泌的E7蛋白可激活A(yù)KT通路,調(diào)控腫瘤細(xì)胞的增殖和轉(zhuǎn)移,這與宮頸癌的發(fā)生發(fā)展關(guān)系密切。Chen等[18]利用免疫組化法檢測了55例胃腺癌患者石蠟手術(shù)標(biāo)本中的mTOR、AKT、VEGF-C、VEGF-D,并計(jì)算了淋巴管密度,結(jié)果表明淋巴管密度與mTOR、AKT、VEGF-C、VEGF-D表達(dá)呈正相關(guān)關(guān)系,提示AKT通路的異常激活可能是眾多惡性腫瘤發(fā)生發(fā)展及淋巴結(jié)轉(zhuǎn)移的重要因素。本研究結(jié)果顯示,宮頸癌1組、宮頸癌2組AKT、p-AKT陽性表達(dá)比例高于其余三組,宮頸癌2組p-AKT陽性表達(dá)比例高于宮頸癌1組,提示AKT、p-AKT高表達(dá)與宮頸癌的發(fā)生和進(jìn)展密切相關(guān),與上述研究結(jié)果一致。
淋巴轉(zhuǎn)移是宮頸癌最常見、最重要的轉(zhuǎn)移途徑之一。Birner等[19]報(bào)道在宮頸癌早期,淋巴管未受侵組5年無病生存率達(dá)84.1%,而淋巴管受侵組僅48.2%。腫瘤細(xì)胞侵入淋巴管與微淋巴管的超微結(jié)構(gòu)有著密切關(guān)系[20]。微淋巴管具有以下特征:管壁很薄,僅由一層連續(xù)的內(nèi)皮細(xì)胞和少量結(jié)締組織構(gòu)成;無基膜或基膜不連續(xù);內(nèi)皮細(xì)胞常相互重疊、連接處常存在間隙,內(nèi)皮外有錨絲等。這些超微結(jié)構(gòu)特點(diǎn)為腫瘤細(xì)胞的侵入提供了結(jié)構(gòu)形態(tài)基礎(chǔ)。本研究發(fā)現(xiàn),宮頸癌淋巴結(jié)轉(zhuǎn)移與LMVD呈正相關(guān)關(guān)系,證實(shí)了上述結(jié)論。我們發(fā)現(xiàn),在宮頸癌組織中,maspin與AKT、p-AKT表達(dá)均呈負(fù)相關(guān)關(guān)系,LMVD與maspin表達(dá)呈負(fù)相關(guān)關(guān)系,LMVD與p-AKT表達(dá)呈正相關(guān)關(guān)系,推測maspin蛋白可能有抑制AKT通路激活的作用,maspin基因失表達(dá)可能與AKT通路異常激活有著密切聯(lián)系,而AKT通路與腫瘤微淋巴管生成有關(guān)。已有研究[5]表明,AKT通路可進(jìn)一步促進(jìn)VEGF-C、VEGF-D、VEGF-3、FGF-2、HGF、IGF、ANG-1等因子表達(dá),促進(jìn)淋巴管生成,最終導(dǎo)致腫瘤細(xì)胞發(fā)生淋巴結(jié)轉(zhuǎn)移。
結(jié)合上述研究結(jié)果,我們推測,maspin表達(dá)下調(diào)可能參與了宮頸癌的發(fā)生發(fā)展,機(jī)制可能與AKT通路異常激活、促進(jìn)腫瘤微淋巴管生成有關(guān)。但本研究實(shí)驗(yàn)方法較為單一,maspin基因?qū)I3K/AKT通路的具體作用機(jī)制以及maspin蛋白的功能靶點(diǎn)仍有待進(jìn)一步研究。
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Expression of maspin, AKT, and p-AKT in cervical carcinoma and its correlation with tumor lymphatic microvessel density
XUZhen,LIUZhiqiang,MENGWei,GUOQizhi,SUNLi
(BinzhouMedicalUniversityHospital,Binzhou256600,China)
Objective To observe the expression changes of maspin, protein kinase B (AKT), and phosphorylated protein kinase B (p-AKT) in the cervical cancer tissues and to analyze its correlation with tumor lymphatic microvessel density (LMVD). Methods Twenty-seven cases of cervical paraffin tissues were collected, including 20 cases of chronic cervicitis (inflammation group), 20 cases of cervical intraepithelial neoplasia (CIN) Ⅰ (CIN1 group), 20 cases of CIN Ⅱ (CIN2 group), 20 cases of CIN Ⅲ (CIN3 group), and 47 cases of cervical cancer tissues (cervical cancer group, including 32 cases without lymph node metastasis of cervical cancer group 1 and 15 cases with lymph node metastasis of cervical cancer group 2). The levels of maspin, AKT, and P-AKT were measured by immunohistochemical SP method, and the LMVD was measured. Results The positive rate of maspin protein in the cervical cancer group 1 and cervical cancer group 2 was lower than that in the CIN3 group (allP<0.05). The positive expression rates of AKT and p-AKT in the cervical cancer group 1 and cervical cancer group 2 were higher than those in the other three groups (allP<0.05). The positive expression rate of p-AKT in the cervical cancer group 1 was higher than that in the cervical cancer group 2 (P<0.05). There was a negative correlation between the expression of maspin and AKT in the cervical cancer tissues (rs=-0.472,P=0.001). There was also a negative correlation between maspin and p-AKT expression (rs=-0.598,P=0.000). LMVD in the cervical cancer groups 1 and 2 were (19.44±2.95) and (23.24±2.46) vessels/mm2, respectively. There was a positive correlation between lymph node metastasis and LMVD (rs=0.44,P=0.000). There was a negative correlation between LMVD and the expression of maspin in the cervical cancer tissues (rs=-0.554,P=0.000). There was a positive correlation between LMVD and p-AKT expression (rs=0.39,P=0.007). Conclusions The expression of AKP and p-AKT is up-regulated in the cervical cancer tissues, and the expression of maspin is down-regulated, which is negatively correlated with both AKT and p-AKT expression. In the cervical cancer tissues, LMVD is negatively correlated with maspin expression, but is positively correlated with AKT expression. The down-regulation of maspin expression may be involved in the development of cervical cancer, and the mechanism may be related to the abnormal activation of AKT pathway and the promotion of tumor micro-lymphangion genesis.
cervical cancer; maspin gene; protein kinase B; lymphatic microvessel density
山東省自然科學(xué)基金資助項(xiàng)目(ZR2012HL01)。
許振(1989-),男,碩士,主要研究方向?yàn)閶D科腫瘤。E-mail:2005891282qq.com
劉志強(qiáng)(1971-),男,博士,教授,主任醫(yī)師,主要研究方向?yàn)閶D科腫瘤。E-mail:2005891282qq.com
10.3969/j.issn.1002-266X.2017.27.006
R737.33
A
1002-266X(2017)27-0023-04
2017-02-27)