張晉弘,劉俊英,劉健,劉月平△
口腔鱗狀細(xì)胞癌中FEZ1和HIF-1α蛋白表達(dá)及預(yù)后研究
張晉弘1,劉俊英2,劉健3,劉月平2△
目的探討抑癌基因FEZ1和缺氧誘導(dǎo)因子(HIF)-1α在口腔鱗狀細(xì)胞癌(OSCC)中的表達(dá)及其與臨床病理特征及預(yù)后的關(guān)系。方法選取OSCC組織標(biāo)本146例,正常黏膜組織標(biāo)本80例,同時選取新鮮OSCC組織、癌旁組織和正常黏膜組織各30例。免疫組化法檢測146例組織標(biāo)本和80例正常黏膜組織中FEZ1和HIF-1α表達(dá),分析二者表達(dá)與患者臨床病理特征及預(yù)后的關(guān)系。Western blot檢測30例新鮮OSCC組織及其對應(yīng)癌旁組織、正常黏膜組織中FEZ1和HIF-1α表達(dá)情況。結(jié)果146例OSCC組織FEZ1蛋白陽性表達(dá)率(30.14%)低于正??谇火つそM織(81.25%),HIF-1α蛋白陽性表達(dá)率(71.23%)高于正常黏膜組織(12.50%,χ2分別為54.076和71.317,均P<0.01)。146例OSCC中FEZ1的表達(dá)水平與臨床分期、腫瘤直徑、分化程度有關(guān),HIF-1α的表達(dá)水平與性別、淋巴結(jié)轉(zhuǎn)移、腫瘤直徑、分化程度有關(guān)。FEZ1α蛋白陽性表達(dá)與陰性表達(dá)患者5年生存率差異無統(tǒng)計學(xué)意義,而HIF-1α蛋白陽性表達(dá)者5年生存率低于陰性表達(dá)患者(P<0.05)。30例正??谇火つそM織、癌旁組織及OSCC組織中,F(xiàn)EZ1表達(dá)水平依次降低(P<0.01),HIF-1α表達(dá)水平依次升高(P<0.01)。結(jié)論FEZ1和HIF-1α可能參與了OSCC的發(fā)生、發(fā)展,檢測FEZ1和HIF-1α表達(dá)可作為OSCC生物學(xué)行為的參考指標(biāo)之一。
口腔鱗狀細(xì)胞癌;FEZ1;缺氧誘導(dǎo)因子-1α;免疫組織化學(xué);蛋白免疫印跡;臨床特征;生存分析
口腔鱗狀細(xì)胞癌(oral squamous cell carcinoma,OSCC)是口腔黏膜較常見的惡性腫瘤之一,嚴(yán)重影響人類健康及生活質(zhì)量。抑癌基因FEZ1(Fascicula?tion and Elongation protein Zeta-1)是食管癌的潛在抑癌基因,位于人類染色體8p22的D8S261位點附近的雜合性缺失區(qū)域[1]。研究發(fā)現(xiàn)該基因的低表達(dá)可促進(jìn)惡性腫瘤的增殖和進(jìn)展[2]。缺氧誘導(dǎo)因子-1α(Hypoxia-inducible Factor-1α,HIF-1α)是在缺氧條件下廣泛存在于人體細(xì)胞內(nèi)的核轉(zhuǎn)錄因子,在細(xì)胞缺氧信號轉(zhuǎn)導(dǎo)與調(diào)控途徑中處于核心地位。目前關(guān)于FEZ1和HIF-1α在OSCC中表達(dá)研究較少,本文擬通過檢測FEZ1和HIF-1α在OSCC中的表達(dá)水平,探討其在OSCC進(jìn)展中所起作用,為臨床診治提供依據(jù)。
1.1 標(biāo)本來源選取河北醫(yī)科大學(xué)第四醫(yī)院病理科2009年12月—2011年12月手術(shù)切除的OSCC石蠟標(biāo)本切片146例。其中男80例,女66例;年齡<50歲42例、≥50歲104例;鱗狀細(xì)胞癌分級高、中、低分化分別為51例、63例、32例。所有患者均經(jīng)手術(shù)治療,術(shù)前未經(jīng)任何治療且均有完整的病理資料和隨訪資料,隨訪時間為手術(shù)日至末次隨訪日2014年12月31日或死亡日。選取同期80例正??谇火つそM織石蠟標(biāo)本切片作為對照。所有切片均在我院病理專家指導(dǎo)下進(jìn)行鱗狀細(xì)胞癌分級復(fù)診。另收集2014年1月—2015年1月手術(shù)切除的30例OSCC新鮮組織,同時留取其癌旁組織,并選取30例非癌患者的正??谇火つそM織作為對照。
1.2 試劑兔抗人FEZ1、HIF-1α多克隆抗體,通用辣根酶標(biāo)記抗生物素IgG抗體,β-actin單克隆抗體,PVDF膜均購自美國Santa Cruz公司??捡R斯亮藍(lán)蛋白測定試劑盒購自福州邁新生物技術(shù)開發(fā)公司。SP免疫組化試劑盒、PBS緩沖液、ECL顯色試劑盒購自北京中杉生物技術(shù)有限公司。
1.3 免疫組化染色146例OSCC組織和80例正??谇火つそM織石蠟標(biāo)本制成4 μm切片后常規(guī)脫蠟至水,抗原修復(fù)后按照說明書步驟進(jìn)行免疫組化染色,顯微鏡下觀察切片。結(jié)果判定標(biāo)準(zhǔn):FEZ1主要定位于胞漿,呈淡黃色至棕褐色顆粒。HIF-1α主要定位于細(xì)胞核,呈黃色或棕黃色顆粒[2-3]。結(jié)合陽性細(xì)胞著色強度與陽性細(xì)胞百分比進(jìn)行半定量,著色強度:無色計0分,黃色計1分,棕黃色計2分,棕褐色計3分。陽性細(xì)胞百分比≤10%計1分,10%~50%計2分,51%~75%計3分,>75%計4分。兩者得分乘積:0分為(-),1~4分為(+),5~8分為(++),9~12分為(+++)。(+)、(++)、(+++)判為陽性,若陽性細(xì)胞百分比≤10%即判為陰性。
1.4 Western blot取-80℃保存的30例OSCC、癌旁及正??谇火つそM織各100 mg放入含PMSF裂解液的研磨器中充分研磨,靜置40 min后4℃離心,取上清,Bradford法測定蛋白濃度。每個樣品取100 μg總蛋白行SDS-PAGE,電泳后轉(zhuǎn)膜,5%脫脂奶粉于37℃封閉2 h。分別加入兔抗人FEZ1(1∶1 000)和兔抗人HIF-1α(1∶1 000),4℃過夜,以β-actin為內(nèi)參,次日加入辣根過氧化酶標(biāo)記二抗(1∶10 000),室溫?fù)u床孵育2 h。TBST洗膜后,ECL化學(xué)發(fā)光顯色。凝膠成像系統(tǒng)進(jìn)行灰度值測定及半定量分析。
1.5 統(tǒng)計學(xué)方法采用SPSS 13.0進(jìn)行數(shù)據(jù)分析。計量資料以均數(shù)±標(biāo)準(zhǔn)差表示,多組間比較采用單因素方差分析;計數(shù)資料以例(%)表示,組間比較采用卡方檢驗;采用Kaplan-Meier法計算生存率及繪制生存曲線,Log-Rank時序檢驗比較生存率差異,生存時間按年計算,P<0.05為差異有統(tǒng)計學(xué)意義。
2.1 免疫組化結(jié)果FEZ1在OSCC細(xì)胞質(zhì)中呈中等強度表達(dá),其陽性表達(dá)率較正常口腔黏膜組織降低(P<0.01);HIF-1α蛋白在OSCC細(xì)胞核中高表達(dá),其陽性表達(dá)率高于正常黏膜組織(P<0.01),見圖1,表1。
Tab.1The positive rates of FEZ1 and HIF-1α in OSCC and normal oral mucosa表1 不同組織中FEZ1和HIF-1α陽性表達(dá)率比較例(%)
2.2 FEZ1和HIF-1α表達(dá)與OSCC臨床病理參數(shù)間的關(guān)系146例OSCC患者中,不同臨床分期、腫瘤直徑、分化程度間FEZ1表達(dá)陽性率差異有統(tǒng)計學(xué)意義(P<0.05)。臨床分期越低,腫瘤直徑越小,分化程度越高,F(xiàn)EZ1表達(dá)陽性率較高。不同性別、臨床分期、有無淋巴結(jié)轉(zhuǎn)移、腫瘤直徑、分化程度間HIF-1α表達(dá)陽性率差異有統(tǒng)計學(xué)意義(P<0.05)。其中男性高于女性,臨床分期越高,存在淋巴結(jié)轉(zhuǎn)移,腫瘤直徑越大,分化程度越低,HIF-1α陽性表達(dá)率較高,見表2。
2.3 FEZ1和HIF-1α蛋白表達(dá)與OSCC5年生存率間的關(guān)系FEZ1表達(dá)陽性組5年生存率81.8%(36/ 44)與陰性組69.6%(71/102)差異無統(tǒng)計學(xué)意義(χ2= 2.989,P>0.05);HIF-1α表達(dá)陽性組5年生存率68.3%(71/104)低于陰性組90.5%(38/42),差異有統(tǒng)計學(xué)意義(χ2=5.077,P<0.05)見圖2。
2.4 Western Blot結(jié)果正常口腔黏膜組織、癌旁組織和OSCC組織中,F(xiàn)EZ1蛋白表達(dá)水平依次降低,HIF-1α蛋白表達(dá)水平依次升高,差異有統(tǒng)計學(xué)意義(P<0.05)見圖3、表3。
Tab.2The relationship between expressions of FEZ1 and HIF-1α and clinical pathological features表2 FEZ1和HIF-1α蛋白陽性表達(dá)率與臨床病理特征的關(guān)系例(%)
Fig.2Kaplan-Meier survival curves of HIF-1α and FEZ1圖2 HIF-1α和FEZ1不同表達(dá)情況患者Kaplan-Meier生存曲線分析
Fig.3The expressions of FEZ1 and HIF-1α protein in different tissues圖3 FEZ1和HIF-1α蛋白在不同組織中的表達(dá)
Tab.3Comparison of expressions of FEZ1 and HIF-1 protein between different tissues表3 不同組織中FEZ1和HIF-1α蛋白的表達(dá)水平比較(n=30)
Tab.3Comparison of expressions of FEZ1 and HIF-1 protein between different tissues表3 不同組織中FEZ1和HIF-1α蛋白的表達(dá)水平比較(n=30)
**P<0.01;a與正常黏膜組織比較,b與癌旁組織比較,P<0.05
組別正常黏膜組織癌旁組織O S C C組織F F E Z 1 4 . 6 8 ± 0 . 1 4 3 . 6 3 ± 0 . 1 3 a 1 . 2 6 ± 0 . 2 3 a b 3 0 8 5 . 4 0 3 * * H I F -1 α 0 . 1 2 ± 0 . 0 4 0 . 2 2 ± 0 . 0 3 a 0 . 3 0 ± 0 . 0 4 a b 2 1 1 . 2 4 3 * *
目前認(rèn)為OSCC的危險因素包括強致癌物的持續(xù)刺激、口腔黏膜長期病損、口腔常見疾病反復(fù)存在及遺傳因素等[4]。了解OSCC的分子水平特征有助于揭示OSCC治療和預(yù)后的分子基礎(chǔ),為探索腫瘤的及早防治提供新的思路。FEZ1為抑癌基因,其主要功能包括抑制腫瘤細(xì)胞生長,調(diào)節(jié)細(xì)胞有絲分裂及神經(jīng)細(xì)胞生長,調(diào)節(jié)參與細(xì)胞運輸?shù)尿?qū)動蛋白與微管蛋白[5]。研究發(fā)現(xiàn)FEZ1在膀胱移行細(xì)胞癌、頭頸部鱗狀細(xì)胞癌、肝細(xì)胞癌及卵巢腺癌組織中表達(dá)缺失或下調(diào)[6-9]。Zhou等[10]對160例結(jié)腸癌患者分析發(fā)現(xiàn),F(xiàn)EZ1表達(dá)下調(diào)與腫瘤增殖活性升高和患者生存率降低密切相關(guān)。本研究發(fā)現(xiàn)FEZ1主要表達(dá)于OSCC細(xì)胞質(zhì),其在OSCC中的陽性表達(dá)率低于正??谇火つそM織,提示FEZ1的表達(dá)下調(diào)與OSCC發(fā)生有一定關(guān)系。其蛋白表達(dá)水平在正??谇火つぁ┡越M織、OSCC中依次降低,說明FEZ1蛋白在正常黏膜到OSCC的癌變過程中存在表達(dá)活性降低。
HIF-1α是介導(dǎo)細(xì)胞對缺氧微環(huán)境進(jìn)行適應(yīng)性反應(yīng)的最關(guān)鍵的核轉(zhuǎn)錄調(diào)控因子,在胰腺癌[3]、肺癌和皮膚癌[11]等多種惡性腫瘤中均存在過度表達(dá)。HIF-1α的主要生物學(xué)效應(yīng)包括促進(jìn)血管形成,促進(jìn)無氧糖酵解、細(xì)胞增殖,調(diào)節(jié)血管張力及機體對放、化療耐受等[12]。羅霞等[13]認(rèn)為HIF-1α可作為口腔黏膜白斑癌變的重要標(biāo)志物之一。本研究發(fā)現(xiàn)OSCC組織中HIF-1α的陽性表達(dá)率高于正常黏膜組織,其表達(dá)水平在正??谇火つぁ┡越M織、OSCC組織中依次升高,表明HIF-1α在口腔黏膜上皮癌變過程中有一定作用。
研究發(fā)現(xiàn)OSCC患者預(yù)后與腫瘤分化程度、增殖活性以及術(shù)前并發(fā)癥有關(guān)[14-15]。Wielscher等[16]發(fā)現(xiàn),F(xiàn)EZ1基因上的5-羥甲基胞嘧啶(5hmc)片段參與了早期乳腺上皮組織的癌變,其表達(dá)水平降低可增加乳腺表觀遺傳學(xué)癌變的風(fēng)險。楊大江等[17]認(rèn)為HIF-1α可能通過上調(diào)血管內(nèi)皮生長因子C(VEGF-
C)表達(dá)來誘導(dǎo)機體淋巴管形成,并最終引起OSCC細(xì)胞發(fā)生區(qū)域淋巴結(jié)轉(zhuǎn)移。本實驗發(fā)現(xiàn),F(xiàn)EZ1陽性表達(dá)率在Ⅰ-Ⅱ期高于Ⅲ-Ⅳ期患者,腫瘤直徑<4 cm組高于腫瘤直徑≥4 cm組,高分化組高于中、低分化組;而HIF-1α陽性表達(dá)率與FEZ1相反,且無淋巴結(jié)轉(zhuǎn)移組低于轉(zhuǎn)移組,提示FEZ1在OSCC的浸潤和轉(zhuǎn)移中有抑制作用,而HIF-1α則起促進(jìn)作用,說明FEZ1蛋白是一種保護(hù)性蛋白,可抑制OSCC的惡性轉(zhuǎn)化;而HIF-1α可促進(jìn)OSCC的惡性進(jìn)展。通過比較FEZ1和HIF-1α表達(dá)陽性組和陰性組的5年生存率發(fā)現(xiàn),F(xiàn)EZ1表達(dá)陽性組與陰性組差異無統(tǒng)計學(xué)意義,而HIF-1α表達(dá)陽性組5年生存率明顯低于陰性組,提示HIF-1α可作為判斷OSCC患者生存率的指標(biāo)之一,而FEZ1尚待擴(kuò)大樣本進(jìn)一步深入研究。
綜上,F(xiàn)EZ1和HIF-1α在OSCC發(fā)生、發(fā)展過程中具有重要作用,檢測FEZ1和HIF-1α表達(dá)情況可作為判斷OSCC生物學(xué)行為的參考指標(biāo)之一。
(圖1見插頁)
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(2015-04-06收稿 2015-06-22修回)
(本文編輯 胡小寧)
Expressions of FEZ1 and HIF-1α protein in oral squamous cell carcinoma and its prognosis
ZHANG Jinhong1,LIU Junying2,LIU Jian3,LIU Yueping2△
1 Department of Stomatology,the First Affiliated Hospital,Hebei Medical University,Shijiazhuang 050031,China;2 Department of Pathology,the Fourth Affiliated Hospital,Hebei Medical University;3 Department of Stomatology,the Fourth Affiliated Hospital,Hebei Medical University△
ObjectiveTo investigate the expressions of tumor suppressor gene FEZ1 and hypoxia inducible factor(HIF)-1α in oral squamous cell carcinoma(OSCC),and their correlation with clinicopathological features and prognosis. MethodsA total of 146 specimens of OSCC and 80 normal oral mucosa were used to detect the expressions of FEZ1 and HIF-1α by immunohistochemistry.Thirty specimens of fresh OSCC tissues,30 samples of the paracancerous tissues and 30 normal mucosa tissues were also included in the study.The relationship between the expressions of FEZ1 and HIF-1α,the clinicopathological features and the prognosis of the patients were analyzed.Western blot assay was used to detect the expres?sions of FEZ1 and HIF-1α in 30 fresh OSCC tissues,30 samples of the paracancerous tissues and 30 normal mucosa tissues. ResultsIn OSCC tissues,the positive rate of FEZ1 protein(30.14%)was significantly lower than that in normal oral muco?sa(81.25%),and the positive rate of HIF-1α protein(71.23%)was significantly higher than that in normal mucosa(12.50%,χ2=54.076 and 71.317,P<0.01).There was a correlation between the expression of FEZ1 and clinical stage,tumor size and differentiation.The expression of HIF-1α was correlated with gender,lymph node metastasis,tumor size and differentiation. There was no significant difference in 5-year survival rate between positive and negative FEZ1 expression groups.The 5-year survival rate was significantly lower in HIF-1α positive expression group than that of HIF-1α negative expression group(P<0.05).The expression level of FEZ1 was decreased by the sequences in normal oral mucosa,paracancerous tissue and OSCC(P<0.01),but the expression level of HIF-1α was increased in turn(P<0.01).ConclusionFEZ1 and HIF-1α may be involved in the occurrence and progress of OSCC.The expressions of FEZ1 and HIF-1α can be used as a reference for the biological behavior of OSCC.
oral squamous cell carcinoma;FEZ1;hypoxia inducible factor-1α;immunohistochemistry;Western blot;clinical features;survival analysis
R782
A
10.11958/j.issn.0253-9896.2015.11.024
河北省衛(wèi)生廳科研基金項目(項目編號20100281)
1河北醫(yī)科大學(xué)第一醫(yī)院口腔科(郵編050031);2河北醫(yī)科大學(xué)第四醫(yī)院病理科;3河北醫(yī)科大學(xué)第四醫(yī)院口腔科
張晉弘(1975),男,碩士,主治醫(yī)師,主要從事口腔頜面外科研究
△通訊作者E-mail:annama@163.com