【摘要】 遺傳變異是導(dǎo)致癌癥發(fā)生和發(fā)展的重要因素之一??截悢?shù)變異是遺傳多樣性的重要來源,在結(jié)構(gòu)上表現(xiàn)為基因的擴(kuò)增或缺失,與腫瘤的發(fā)生和發(fā)展有關(guān)。采用高通量測序和基因芯片技術(shù)可以檢測拷貝數(shù)的變異情況,提供相關(guān)的腫瘤分子特征、預(yù)后和治療相關(guān)的信息,有利于臨床上對患者進(jìn)行更準(zhǔn)確的診斷和治療決策。卵巢癌在女性生殖系統(tǒng)疾病中的病死率極高,了解其發(fā)病機(jī)制對提高卵巢癌患者的生存率至關(guān)重要。目前拷貝數(shù)變異在卵巢癌中的具體作用和機(jī)制仍然不清楚,文章就現(xiàn)有的研究結(jié)果對與卵巢癌相關(guān)的拷貝數(shù)變異進(jìn)行綜述,以期為卵巢癌的預(yù)防、診斷及治療等方面提供新的思路和方法。
【關(guān)鍵詞】 拷貝數(shù)變異;卵巢腫瘤;高通量測序;基因芯片;遺傳變異
Research progress in copy number variation in ovarian cancer
SUN Mengna, XU Ying, REN Chenlu, YAN Yufan, CHEN Zhihao, YANG Hong
(Department of Gynecology and Obstetrics, the First Affiliated Hospital of Air Force Military Medical University, Xi’ an 710032, China)
Corresponding author: YANG Hong, E-mail: yanghong@fmmu.edu.cn
【Abstract】 Genetic variation is one of the important factors leading to the incidence and development of cancer. Copy number variation is an important source of genetic diversity, which can be expressed as gene amplification or deletion in structure, and is related to the occurrence and development of different tumors. High-throughput sequencing and gene chip technology can be adopted to detect the variation of copy number, and provide relevant information about tumor molecular characteristics, prognosis and treatment, which is conducive to more accurate diagnosis and treatment decisions for patients in clinical practice. Ovarian cancer is one of the female reproductive system diseases with the highest mortality rate. Understanding its pathogenesis is of significance for improving the survival rate of ovarian cancer. At present, the specific role and mechanism of copy number variation in ovarian cancer are still unclear. In this article, relevant copy number variation in ovarian cancer was reviewed based on the existing research results, aiming to provide novel ideas and methods for the prevention, diagnosis and treatment of ovarian cancer.
【Key words】 Copy number variation; Ovarian cancer; High-throughput sequencing; Gene chip; Genetic variation
卵巢癌在婦科惡性腫瘤中極具致命性,其早期病變不易發(fā)現(xiàn),晚期缺乏有效的治療手段,具有耐藥、復(fù)發(fā)率和病死率高的特點(diǎn),嚴(yán)重性不容忽視[1]。深入了解其發(fā)病機(jī)制,可以提高對卵巢癌的早期診斷和治療效果[2]??截悢?shù)變異(copy number variation, CNV)指染色體上DNA片段的重復(fù)擴(kuò)增或缺失,屬于結(jié)構(gòu)變異,可導(dǎo)致包括惡性腫瘤在內(nèi)的復(fù)雜疾病發(fā)生和發(fā)展[3-4]。近年來,關(guān)于腫瘤與CNV關(guān)系的研究不斷,但在腫瘤中的具體作用機(jī)制和特點(diǎn)尚未明確和總結(jié)[5]。本文重點(diǎn)探討CNV與卵巢癌的關(guān)系,旨在為制定個(gè)體化治療策略和提高卵巢癌患者生存率提供參考。
1 CNV在腫瘤中的相關(guān)研究
1.1 CNV增加腫瘤的易患性
CNV是遺傳多樣性的重要來源,可促進(jìn)腫瘤發(fā)生和進(jìn)展[6-7]。Hashemi等[8]利用薈萃分析得出的數(shù)據(jù)表明,載脂蛋白B mRNA編輯催化多肽樣3(apolipoprotein B mRNA-editing catalytic polypeptide-like 3,APOBEC3)基因家族的拷貝數(shù)缺失與乳腺癌易患性增加明顯相關(guān)。Wang等[9]通過對公共數(shù)據(jù)庫的數(shù)據(jù)挖掘和病例對照研究,發(fā)現(xiàn)攜帶HLA-DQB1基因拷貝數(shù)擴(kuò)增的個(gè)體發(fā)生結(jié)腸癌的風(fēng)險(xiǎn)降低。Jin等[10]基于全基因組單核苷酸多態(tài)性(single nucleotide polymorphism,SNP)陣列,在染色體2p24.3處發(fā)現(xiàn)了一種常見的拷貝數(shù)缺失現(xiàn)象,這與前列腺癌的發(fā)生風(fēng)險(xiǎn)相關(guān)。他們還在20p13區(qū)發(fā)現(xiàn)了位于信號(hào)調(diào)節(jié)蛋白β-1(signal-regulatory protein beta-1,SIRPB1)基因內(nèi)部長32.3 kb的拷貝數(shù)多態(tài)性2454序列(copy-number polymorphism,CNP2454)與前列腺癌的侵襲性相關(guān),推測染色體20p13區(qū)位點(diǎn)的遺傳變異可能是導(dǎo)致前列腺癌進(jìn)展的原因。CNV可能與腫瘤的易患性相關(guān),增加患者發(fā)病風(fēng)險(xiǎn)。
1.2 CNV加速腫瘤進(jìn)展
O’Malley等[11]發(fā)現(xiàn)前列腺癌中拷貝數(shù)缺失比擴(kuò)增常見,染色體21q21.2-21q21.3上2.7 Mb區(qū)域的缺失,會(huì)導(dǎo)致跨膜絲氨酸蛋白酶2(transmembrane serine proteinase 2, TMPRSS2)與E-26轉(zhuǎn)化特異性相關(guān)基因(E26 transformation-specific-related gene,
ERG)融合,形成TMPRSS2-ERG基因,此融合基因可增加細(xì)胞增殖和遷移,與前列腺癌的嚴(yán)重性相關(guān)。Tanaka等[12]通過多組學(xué)整合方法發(fā)現(xiàn),結(jié)直腸癌存在染色體7p和7q區(qū)拷貝數(shù)擴(kuò)增,17p和22q區(qū)拷貝數(shù)缺失。上述區(qū)域位點(diǎn)的CNV會(huì)加快轉(zhuǎn)移性腫瘤的進(jìn)展[13]。Behroozi等[14]通過檢測42例胃癌患者的作用于RNA的腺苷脫氨酶(adenosine deaminase acting in RNA,ADAR)基因和CNV情況,發(fā)現(xiàn)ADAR在胃癌中高表達(dá),其基因拷貝數(shù)多擴(kuò)增,ADAR高表達(dá)和拷貝數(shù)擴(kuò)增的胃癌患者腫瘤體積更大、腫瘤分期更高,該結(jié)果提示ADAR的表達(dá)和CNV在胃癌的Ⅲ期至Ⅳ期進(jìn)展中起著重要作用。Carron等[15]通過微陣列分析,發(fā)現(xiàn)含有癌基因FGF18的5q35.1區(qū)的拷貝數(shù)缺失導(dǎo)致口咽癌患者的總生存期更差,含有細(xì)胞周期蛋白依賴性激酶(cyclin dependent kinase, CDK)10的16q24.3區(qū)和參與端粒維持的RAD18基因的3p25.3區(qū)的拷貝數(shù)缺失導(dǎo)致口咽癌患者的總生存期更好。該研究還表明,在頭頸癌中9p13.3區(qū)的PTENP1基因拷貝數(shù)缺失抑制了腫瘤細(xì)胞增殖和遷移。CNV與腫瘤的增殖、遷移、嚴(yán)重性及患者預(yù)后密切相關(guān),其中包括前列腺癌中的TMPRSS2-ERG基因融合、結(jié)直腸癌的染色體7p和7q擴(kuò)增、胃癌中ADAR基因的高表達(dá)和擴(kuò)增,以及口咽癌中FGF18、CDK10和RAD18基因的拷貝數(shù)缺失與患者生存期的關(guān)聯(lián)。CNV與腫瘤細(xì)胞的增殖、遷移相關(guān),對患者的病情進(jìn)展及預(yù)后有一定影響,可考慮作為腫瘤進(jìn)展及患者預(yù)后評(píng)價(jià)的標(biāo)志物。
1.3 CNV影響腫瘤靶向治療的效果
非小細(xì)胞肺癌(non-small cell lung cancer,NSCLC)
在肺癌中病死率位居前位,酪氨酸酶抑制劑(tyro-sine kinase inhibitors,TKI)可用于NSCLC的治療。He等[16]發(fā)現(xiàn),染色體1p13.1-p13.3拷貝數(shù)擴(kuò)增的EGFR突變型NSCLC患者對TKI的反應(yīng)較差,染色體14q13.1-q31.3拷貝數(shù)擴(kuò)增的患者對TKI的反應(yīng)良好。Wang等[17]通過數(shù)字PCR檢測發(fā)現(xiàn),人表皮生長因子受體2(human epidermal growth factor receptor 2,HER2)CNV對指導(dǎo)乳腺癌腫瘤靶向治療具有重要意義。研究結(jié)果表明,染色體CNV可成為腫瘤靶向治療的反應(yīng)和患者預(yù)后的預(yù)測指標(biāo)。
2 CNV檢測方法
CNV檢測技術(shù)在腫瘤遺傳學(xué)和先天性異常產(chǎn)前診斷中應(yīng)用廣泛。目前主要有熒光原位雜交(fluorescence in situ hybridization, FISH)、高通量測序、基因芯片及單分子基因測序技術(shù)。
2.1 熒光原位雜交技術(shù)
FISH技術(shù)主要是利用熒光標(biāo)記的特異單鏈DNA分子探針,根據(jù)堿基互補(bǔ)配對原則來檢測細(xì)胞和組織內(nèi)的RNA或DNA[18],在分子生物和細(xì)胞遺傳學(xué)中應(yīng)用廣泛。FISH技術(shù)安全性和靈敏度高、檢測速度較快。然而,F(xiàn)ISH圖像往往存在對比度低、細(xì)胞邊界不清、潛在細(xì)胞缺陷等問題,阻礙了細(xì)胞的完整識(shí)別和有效分割[19],在檢測低拷貝核酸時(shí)的有效性有限[20],常用于對已知基因序列的定位、定性和CNV的驗(yàn)證。
2.2 高通量測序技術(shù)
高通量測序又稱下一代測序(next-generation sequencing,NGS),可一次性對大量核酸分子進(jìn)行平行序列測定,產(chǎn)出的測序數(shù)據(jù)通常超過100 Mb,可以精確了解每個(gè)堿基的變異情況,分辨率高。但該測序過程中使用了PCR技術(shù),不可避免地會(huì)導(dǎo)致一定程度的精確度缺失。臨床應(yīng)用中,采用高通量測序技術(shù)的有全基因組測序(whole genome sequencing,WGS)、拷貝數(shù)測序以及光學(xué)基因組圖譜(optical genome mapping,OGM)。WGS是針對人類個(gè)體中完整基因組所有堿基進(jìn)行的測序,不需要細(xì)胞培養(yǎng)步驟,檢測時(shí)間短,測序信息量大,結(jié)果全面,可應(yīng)用于基因變異、結(jié)構(gòu)變異檢測[21]??截悢?shù)測序采用低深度WGS的方法來檢測DNA序列中是否存在結(jié)構(gòu)變異,可從基因組的隨機(jī)片段中平行測序大量短DNA鏈[22],由于其檢測周期短、通量高、成本低、診斷準(zhǔn)確,臨床上多用于檢測染色體疾病。OGM通過標(biāo)記DNA分子上特異性的識(shí)別序列,再結(jié)合圖像分析技術(shù)來實(shí)現(xiàn)完整DNA分子上信號(hào)模式的可視化分析。這種檢測方法分辨率高,能夠精確細(xì)化變異位置,但對在靠近著絲粒等無標(biāo)記和缺乏參考序列的區(qū)域無法檢測[23],臨床上可用于腫瘤、遺傳病、產(chǎn)前診斷的檢測。
2.3 基因芯片技術(shù)
基因芯片技術(shù)又稱DNA微陣列。其原理是將固定在相應(yīng)處理過的載體上有特定序列的DNA探針與被標(biāo)記的待測樣品進(jìn)行雜交,通過雜交信號(hào)的強(qiáng)弱分布,來分析有無目的分子及其數(shù)量和序列,從而獲得受檢樣品的遺傳信息。其中染色體微陣列分析是臨床上常使用的相關(guān)技術(shù),簡單高效、結(jié)果準(zhǔn)確,但受芯片設(shè)計(jì)限制,該技術(shù)無法有效地檢測出染色體的平衡易位和倒位以及特定位點(diǎn)和新發(fā)的異常[24],臨床上常被用于腫瘤、遺傳病和產(chǎn)前診斷篩查。
2.4 單分子基因測序技術(shù)
單分子基因測序可直接對目標(biāo)序列進(jìn)行檢測,無需進(jìn)行PCR過程,該測序技術(shù)不僅可以有效避免因PCR偏向性而導(dǎo)致的系統(tǒng)錯(cuò)誤,同時(shí)保持了NGS技術(shù)高通量、低成本、測序時(shí)間短的優(yōu)點(diǎn)。但該技術(shù)不成熟、檢測堿基錯(cuò)誤率高,對CNV檢測適用性不強(qiáng),不適合大規(guī)模應(yīng)用[25],目前可應(yīng)用于基因組學(xué)測序、甲基化研究、蛋白質(zhì)測序檢測。
因此,F(xiàn)ISH技術(shù)及基因芯片技術(shù)測序覆蓋程度有限,單分子基因測序技術(shù)不成熟,不適合大規(guī)模分析,在臨床應(yīng)用中受到限制。相比之下,高通量測序技術(shù)速度快、通量高、成本低,可以實(shí)現(xiàn)合成和測序同時(shí)進(jìn)行,可適用性廣,臨床檢測應(yīng)用效果良好。
3 與卵巢癌相關(guān)的CNV
3.1 CNV與卵巢癌患病風(fēng)險(xiǎn)
根據(jù)組織類型可將卵巢腫瘤分為上皮性腫瘤、生殖細(xì)胞腫瘤、性索間質(zhì)瘤及轉(zhuǎn)移性腫瘤,上皮性卵巢癌(epithelial ovarian cancer,EOC)是最常見的組織學(xué)類型,其中高級(jí)別漿液性卵巢癌(high-grade serous ovarian cancer,HGSOC)約占卵巢癌的70%[26]。
Reid Brett等[27]用Illumina610k和HumanOmni2.5M
陣列對約3 500例EOC病例和對照組DNA中的CNV進(jìn)行全基因組分析,在610k陣列組內(nèi)鑒定出染色體1p36.33、8p21.2的拷貝數(shù)缺失與EOC發(fā)生風(fēng)險(xiǎn)降低相關(guān),染色體1p13.3區(qū)域拷貝數(shù)缺失、12p11.21區(qū)域拷貝數(shù)擴(kuò)增、19q13.2區(qū)域拷貝數(shù)缺失以及19q13.42區(qū)域拷貝數(shù)擴(kuò)增與EOC發(fā)生風(fēng)險(xiǎn)增加相關(guān)。在2.5M組中鑒定出染色體2q34的拷貝數(shù)缺失與EOC發(fā)生低風(fēng)險(xiǎn)相關(guān),5p15.2拷貝數(shù)缺失與高風(fēng)險(xiǎn)相關(guān)。1p36.33的大缺失是唯一與腫瘤轉(zhuǎn)錄獨(dú)立相關(guān)的CNV,攜帶該片段缺失者患EOC的風(fēng)險(xiǎn)降低約70%,腫瘤組織分析顯示,攜帶者CDK11的表達(dá)較低。CDK11參與細(xì)胞周期控制、轉(zhuǎn)錄調(diào)節(jié)和凋亡過程[28],推測1p36.33缺失攜帶者中觀察到的EOC風(fēng)險(xiǎn)降低可能是通過CDK11相關(guān)致癌信號(hào)傳導(dǎo)減少而實(shí)現(xiàn)的。另外,在610k組中包含細(xì)胞色素P450家族2亞家族A成員(cytochrome P450 family 2 subfamily A member 7,CYP2A7)基因的染色體19q13.2的拷貝數(shù)缺失使卵巢癌風(fēng)險(xiǎn)增加,但在Hakkaart等[29]的研究中發(fā)現(xiàn),乳腺癌易感基因1 (breast cancer susceptibility gene 1,BRCA1)突變攜帶者中相同的缺失區(qū)域與卵巢癌風(fēng)險(xiǎn)降低相關(guān),因此CYP2A7位點(diǎn)缺失的一致檢測及其與EOC患病風(fēng)險(xiǎn)的相關(guān)性值得進(jìn)一步研究。
Reid Brett等[27]的研究集中于常見的CNV與EOC風(fēng)險(xiǎn)的全基因組分析。之后,DeVries等[30]通過使用全基因組分析研究了與卵巢癌風(fēng)險(xiǎn)相關(guān)的罕見CNV,在與EOC和HGSOC風(fēng)險(xiǎn)相關(guān)的非蛋白質(zhì)編碼DNA區(qū)域內(nèi)分別發(fā)現(xiàn)了1 707個(gè)和1 948個(gè)CNV,在BRCA1基因位點(diǎn)上發(fā)現(xiàn)了具有高度統(tǒng)計(jì)學(xué)意義的拷貝數(shù)缺失和重復(fù),以及RAD51C和BRCA2基因CNV與卵巢癌風(fēng)險(xiǎn)相關(guān)的證據(jù)。同時(shí)還發(fā)現(xiàn)了既往報(bào)道中與EOC風(fēng)險(xiǎn)無關(guān)的關(guān)聯(lián)基因作用,如位于染色體9q21.11位點(diǎn)上的cAMP依賴性蛋白激酶催化亞基γ(protein kinase catalytic subunit gamma,PRKACG),其基因拷貝數(shù)擴(kuò)增與所有EOC病例的風(fēng)險(xiǎn)降低相關(guān);位于1p36.21位點(diǎn)上的細(xì)絲蛋白結(jié)合LIM蛋白1(filamin-binding LIM protein 1,F(xiàn)BLIM1),其拷貝數(shù)缺失與EOC病例的風(fēng)險(xiǎn)增加相關(guān);以及4q21.23位點(diǎn)上的GTPase激活蛋白24(Rho GTPase activating protein,ARHGAP24),其基因拷貝數(shù)缺失和重復(fù)均與HGSOC風(fēng)險(xiǎn)增加相關(guān)。此外,Agiannitopoulos等[31]在癌癥患者中發(fā)現(xiàn)CNV可以提高診斷率,卵巢癌患者中CNV占致病變異的6.8%,基因BRCA1第19外顯子缺失是最常見的CNV,可增加患癌風(fēng)險(xiǎn)。焦孔素(gasdermins,GSDM)是孔隙形成效應(yīng)蛋白家族的成員,Berkel等[32]發(fā)現(xiàn)編碼GSDMC和GSDMD蛋白的基因在卵巢癌中拷貝數(shù)頻繁擴(kuò)增,這與它們在漿液性卵巢癌中的上調(diào)表達(dá)一致,推測其差異表達(dá)和拷貝數(shù)變化可能與漿液性卵巢癌的發(fā)展有關(guān)。綜合來看,CNV與卵巢癌的患病風(fēng)險(xiǎn)密切相關(guān),可能通過影響基因的表達(dá)和功能,從而增加患病風(fēng)險(xiǎn)。
3.2 CNV與卵巢癌的進(jìn)展
卵巢癌的發(fā)生是復(fù)雜、多方面的,遺傳變異是卵巢癌發(fā)生、發(fā)展的重要因素[33]。CNV在卵巢癌進(jìn)展過程中表達(dá)水平不同。Ban等[34]通過GISTIC 2.0算法獲得單個(gè)卵巢癌樣本的基因水平CNV估計(jì),發(fā)現(xiàn)卵巢癌患者腫瘤中存在大量的染色體改變,早期卵巢癌組表現(xiàn)出較高的CNV水平,并且與拷貝數(shù)缺失相比,拷貝數(shù)擴(kuò)增表現(xiàn)出更高水平差異。CNV對長鏈非編碼RNA(long non-coding RNA, lncRNA)表達(dá)的影響可能是卵巢癌等疾病的發(fā)病機(jī)制之一,Zheng等[35]從腫瘤基因組圖譜(The Cancer Genome Atlas,TCGA)數(shù)據(jù)庫中下載了564例卵巢癌患者數(shù)據(jù),通過GISTIC 2.0對卵巢癌基因組中頻繁變化的區(qū)域進(jìn)行鑒定,發(fā)現(xiàn)拷貝數(shù)總體上與lncRNA的表達(dá)呈正相關(guān),lncRNA的拷貝數(shù)缺失明顯多于拷貝擴(kuò)增,提示lncRNA拷貝缺失可能與卵巢癌的發(fā)生和發(fā)展有關(guān)。循環(huán)游離DNA(circulating-free DNA, cfDNA)是通過壞死、凋亡或活性細(xì)胞分泌并釋放到血漿中的細(xì)胞外核酸片段,當(dāng)機(jī)體發(fā)生疾病如惡性腫瘤時(shí),異常壞死的細(xì)胞會(huì)釋放大量DNA進(jìn)入血液循環(huán)[36]。Chen等[37]分析了卵巢腫瘤中血漿cfDNA拷貝數(shù)差異,發(fā)現(xiàn)與非惡性卵巢腫瘤相比,卵巢癌顯示出更深程度的染色體不穩(wěn)定性和廣泛的全身性疾病,cfDNA拷貝數(shù)缺失或擴(kuò)增的基因主要與惡性腫瘤尤其是卵巢癌相關(guān)。惡性腫瘤患者中最常擴(kuò)增的CNV區(qū)域位于染色體1q、3q、6p、7q和8q,最常缺失的CNV區(qū)域位于染色體4p、5q、8p、12q、13q、15q和22q?;蚪M拷貝數(shù)分布改變,表明早期和晚期惡性腫瘤之間存在差異,與早期患者相比,晚期卵巢癌患者最常擴(kuò)增的染色體臂為1q、3q、7q、8q和11q,缺失的染色體臂為4q、5q、6q、8p、12q、13q、15q、16q和22q,并且晚期卵巢癌患者中富集了更多具有CNV改變的基因,因此利用cfDNA CNV或可有助于監(jiān)測卵巢癌的進(jìn)展。
3.3 CNV與卵巢癌的治療及預(yù)后
尋找相關(guān)的生物標(biāo)志物對提高卵巢癌患者的臨床療效具有重要意義[38-39]。目前卵巢癌的臨床治療手段為手術(shù)聯(lián)合鉑和紫杉類藥物化學(xué)治療(化療),然而化療耐藥是其治療的主要臨床挑戰(zhàn),克服卵巢癌化療耐藥將大大提高患者的生存率。HGSOC的特點(diǎn)是初始化療靈敏度高,但許多卵巢癌患者容易復(fù)發(fā),5年后生存率僅為20%~30%[40]。
Esplen等[41]在HGSOC患者染色體中觀察,發(fā)現(xiàn)常有細(xì)胞周期素E1(cyclin E1, CCNE1)和MYC基因拷貝數(shù)擴(kuò)增,以及RB1、NF1和磷酸酶緊張素同源物(phosphatase and tensin homolog,PTEN)基因拷貝數(shù)缺失。Chan等[42]發(fā)現(xiàn),CCNE1高水平拷貝數(shù)擴(kuò)增與HGSOC的不良預(yù)后以及化療耐藥有關(guān),且CCNE1基因拷貝數(shù)擴(kuò)增和不良預(yù)后并不僅限于HGSOC,在卵巢透明細(xì)胞癌中,CCNE1 過表達(dá)也與不良預(yù)后有關(guān)。Pesenti等[43]通過低深度WGS研究了EOC患者體細(xì)胞CNV的基因組分布,發(fā)現(xiàn)HGSOC患者FIGO I期和Ⅱ期常有8q24.21上MYC基因拷貝數(shù)擴(kuò)增,與較差的預(yù)后相關(guān),位于13q14.11上的腫瘤抑制基因RB1拷貝數(shù)缺失發(fā)生在腫瘤進(jìn)展的早期階段,與HGSOC不同的臨床結(jié)局和治療反應(yīng)相關(guān)。Adamson等[44]檢測到HGSOC患者中位于19p13.12上的NOTCH3基因拷貝數(shù)擴(kuò)增和表達(dá)上調(diào),研究發(fā)現(xiàn)NOTCH3的擴(kuò)增與較短的無復(fù)發(fā)生存期相關(guān),NOTCH3通路的上調(diào)與腫瘤進(jìn)展、耐藥和HGSOC復(fù)發(fā)有關(guān),這表明NOTCH3抑制劑可能是一種有效的治療方法,可增加對鉑類藥物治療的敏感性。Wu等[45]在31例卵巢癌患者中發(fā)現(xiàn)50%出現(xiàn)NBN基因拷貝數(shù)擴(kuò)增,其通過促進(jìn)ATM-S1981的磷酸化和同源依賴性重組效率導(dǎo)致BRCA1依賴性奧拉帕尼耐藥,DNA損傷修復(fù)基因拷貝數(shù)擴(kuò)增可導(dǎo)致化療耐藥和總生存率降低,可以作為監(jiān)測卵巢癌病情進(jìn)展的生物標(biāo)志物。Jamalzadeh等[46]發(fā)現(xiàn)野生型KRAS基因拷貝數(shù)擴(kuò)增是HGSOC化療耐藥的驅(qū)動(dòng)因素,可能是卵巢癌潛在的治療靶點(diǎn)。Graf等[47]通過遺傳關(guān)聯(lián)研究,發(fā)現(xiàn)CNV對卵巢癌患者總生存期的風(fēng)險(xiǎn)評(píng)分獨(dú)立于當(dāng)前卵巢癌基因組生物標(biāo)志物,甚至預(yù)測性更強(qiáng)。Berkel等[48]也發(fā)現(xiàn)與正常卵巢組織相比,中心體蛋白89(centrosomal protein 89,CEP89)基因在卵巢癌中過表達(dá)且基因拷貝數(shù)擴(kuò)增,與低表達(dá)患者相比,高表達(dá)患者的總生存期縮短了1年多。研究表明,CEP89是卵巢癌患者總體生存的一個(gè)有價(jià)值的預(yù)測因子,可成為卵巢癌的一個(gè)新的治療靶點(diǎn)。綜上,基因CNV可影響卵巢癌的藥物靈敏度、耐藥性,了解不同基因CNV的情況有助于指導(dǎo)患者治療選擇和制定個(gè)體化治療策略。
4 結(jié)語與展望
隨著高通量測序技術(shù)的突破和發(fā)展,CNV的檢測更加全面和準(zhǔn)確,人們對腫瘤的發(fā)生及進(jìn)展機(jī)制也有了更深入的了解。多項(xiàng)研究通過對卵巢癌標(biāo)本進(jìn)行WGS,評(píng)估CNV頻率,加深了研究者對卵巢癌遺傳學(xué)的理解,而CNV與乳腺癌、結(jié)直腸癌、胃癌、膽管癌、前列腺癌等其他腫瘤也存在相關(guān)性,值得研究總結(jié)。CNV可能增加患癌風(fēng)險(xiǎn),在臨床實(shí)踐中或許可以用作卵巢癌疾病診斷和預(yù)后的生物標(biāo)志物以及卵巢癌藥物研發(fā)的靶點(diǎn)。
然而,目前針對CNV在卵巢癌發(fā)生和發(fā)展機(jī)制中的研究仍然不充分,許多關(guān)鍵問題尚待解答例如CNV在不同卵巢癌亞型中的具體作用、CNV與腫瘤微環(huán)境之間的相互作用以及CNV對卵巢癌治療反應(yīng)的影響等。為了更全面地理解CNV在卵巢癌中的角色,期望未來有更多的學(xué)者加入這一研究領(lǐng)域,通過擴(kuò)大研究樣本量、采用多組學(xué)分析方法,結(jié)合臨床數(shù)據(jù),進(jìn)一步深入探究和驗(yàn)證CNV與腫瘤發(fā)生機(jī)制間的關(guān)系。這不僅有助于揭示卵巢癌的分子機(jī)制,也可為卵巢癌的早期診斷、精準(zhǔn)治療和預(yù)后評(píng)估提供新的視角和工具。
參 考 文 獻(xiàn)
[1] 王靜, 王鳳蝶, 黎丹, 等. 婦科惡性腫瘤患者鉑類抗腫瘤藥物新的不良反應(yīng)[J]. 西南醫(yī)科大學(xué)學(xué)報(bào), 2023, 46(3): 233-236. DOI: 10.3969/j.issn.2096-3351.2023.03.010.
WANG J, WANG F D, LI D, et al. New adverse reactions to platinum-based anti-tumor drugs in gynecological cancer patients[J].
J Southwest Med Univ, 2023, 46(3): 233-236. DOI: 10.3969/
j.issn.2096-3351.2023.03.010.
[2] KONSTANTINOPOULOS P A, MATULONIS U A. Clinical and translational advances in ovarian cancer therapy[J]. Nat Cancer, 2023, 4(9): 1239-1257. DOI: 10.1038/s43018-023-00617-9.
[3] P?S O, RADVANSZKY J, BUGLYó G, et al. DNA copy number variation: Main characteristics, evolutionary significance, and pathological aspects[J]. Biomed J, 2021, 44(5): 548-559. DOI: 10.1016/j.bj.2021.02.003.
[4] 張彥, 孫櫻桐, 許藝明, 等. 醫(yī)學(xué)外顯子組測序檢測遺傳病拷貝數(shù)變異的初步探索[J]. 中山大學(xué)學(xué)報(bào)(醫(yī)學(xué)版), 2019,
40(1): 144-149. DOI: 10.13471/j.cnki.j.sun.yat-sen.univ(med sci). 2019.0020.
ZHANG Y, SUN Y T, XU Y M, et al. Primary investigation for copy number variation detection in genetic diseases with medical exome sequencing [J]. J Sun Yat-sen Univ(Med Sci), 2019,
40(1): 144-149. DOI: 10.13471/j.cnki.j.sun.yat-sen.univ(med sci). 2019.0020.
[5] CHEN S, WU Y, WANG S, et al. A risk model of gene signatures for predicting platinum response and survival in ovarian cancer [J]. J Ovarian Res, 2022, 15(1): 39. DOI: 10.1186/s13048-022-00969-3.
[6] AUWERX C, J?ELOO M, SADLER M C, et al. Rare copy-number variants as modulators of common disease susceptibility [J].
Genome Med, 2024, 16(1): 5. DOI: 10.1186/s13073-023-01265-5.
[7] LAUER S, GRESHAM D. An evolving view of copy number variants[J]. Curr Genet, 2019, 65(6): 1287-1295. DOI: 10.1007/s00294-019-00980-0.
[8] HASHEMI M, MOAZENI-ROODI A, TAHERI M. Association of APOBEC3 deletion with cancer risk: a meta-analysis of 26225 cases and 37201 controls[J]. Asia Pac J Clin Oncol, 2019,
15(6): 275-287. DOI: 10.1111/ajco.13107.
[9] WANG K, YU X, JIANG H, et al. Genome-wide expression profiling-based copy number variations and colorectal cancer risk in Chinese[J]. Mol Carcinog, 2019, 58(7): 1324-1333. DOI: 10.1002/mc.23015.
[10] JIN G, SUN J, LIU W, et al. Genome-wide copy-number variation analysis identifies common genetic variants at 20p13 associated with aggressiveness of prostate cancer[J]. Carcinogenesis, 2011, 32(7): 1057-1062. DOI: 10.1093/carcin/bgr082.
[11] O’MALLEY D E, RASPIN K, MELTON P E, et al. Acquired copy number variation in prostate tumours: a review of common somatic copy number alterations, how they are formed and their clinical utility[J]. Br J Cancer, 2024, 130(3): 347-357. DOI: 10.1038/s41416-023-02485-7.
[12] TANAKA A, OGAWA M, ZHOU Y, et al. Proteogenomic characterization of primary colorectal cancer and metastatic progression identifies proteome-based subtypes and signatures [J].Cell Rep, 2024, 43(2): 113810. DOI: 10.1016/j.celrep.2024.113810.
[13] ZHONG J, WU X, GAO Y, et al. Circular RNA encoded MET variant promotes glioblastoma tumorigenesis[J]. Nat Commun, 2023, 14(1): 4467. DOI: 10.1038/s41467-023-40212-1.
[14] BEHROOZI J, SHAHBAZI S, BAKHTIARIZADEH M R, et al. ADAR expression and copy number variation in patients with advanced gastric cancer[J]. BMC Gastroenterol, 2020, 20(1): 152. DOI: 10.1186/s12876-020-01299-8.
[15] CARRON J, TORRICELLI C, SILVA J K, et al. Association of inherited copy number variation in ADAM3A and ADAM5 pseudogenes with oropharynx cancer risk and outcome[J]. Genes, 2022, 13(12): 2408. DOI: 10.3390/genes13122408.
[16] HE H, MA H, CHEN Z, et al. Chromosomal copy number variation predicts EGFR-TKI response and prognosis for patients with non-small cell lung cancer[J]. Pharmgenomics Pers Med, 2023, 16: 835-846. DOI: 10.2147/PGPM.S418320.
[17] WANG X, XING D, LIU Z, et al. Establishment and evaluation of digital PCR methods for HER2 copy number variation in breast cancer[J]. Anal Bioanal Chem, 2023, 415(4): 725-733. DOI: 10.1007/s00216-022-04466-w.
[18] ZHOU W, HUANG J, YANG X, et al. Detection of dsRNA with fluorescence in situ hybridization (FISH)[J]. Methods Mol Biol, 2024, 2771: 35-38. DOI: 10.1007/978-1-0716-3702-9_6.
[19] SHI L, FENG X, YUE M, et al. Fluorescence in situ hybridi-zation cell image segmentation method[J]. Stud Health Technol Inform, 2023, 308: 216-224. DOI: 10.3233/SHTI230842.
[20] ZHAO F, GUAN Y, SU F, et al. Lanthanide-complex-enhanced bioorthogonal branched DNA amplification[J]. Anal Chem, 2024, 96(4): 1556-1564. DOI: 10.1021/acs.analchem.3c04274.
[21] VAN DE VEN M, SIMONS M J H G, KOFFIJBERG H, et al. Whole genome sequencing in oncology: using scenario drafting to explore future developments[J]. BMC Cancer, 2021, 21(1): 488. DOI: 10.1186/s12885-021-08214-8.
[22] 呂康琪, 陳大洋, 闞麗娟, 等. 基于高通量測序的拷貝數(shù)變異檢測技術(shù)在產(chǎn)前診斷中的臨床應(yīng)用[J]. 檢驗(yàn)醫(yī)學(xué)與臨床, 2022, 19(15): 2142-2145. DOI: 10.3969/j.issn.1672-
9455.2022.15.034.
Lü K Q, CHEN D Y, KAN L J, et al. Clinical application of copy number variation detection technology based on high-throughput sequencing in prenatal diagnosis[J]. Lab Med Clin, 2022, 19(15): 2142-2145. DOI: 10.3969/j.issn.1672-9455.2022.15.034.
[23] SAHAJPAL N S, BARSEGHYAN H, KOLHE R, et al. Optical genome mapping as a next-generation cytogenomic tool for detection of structural and copy number variations for prenatal genomic analyses[J]. Genes, 2021, 12(3): 398. DOI: 10.3390/genes12030398.
[24] SAHAJPAL N S, MONDAL A K, FEE T, et al. Clinical validation and diagnostic utility of optical genome mapping in prenatal diagnostic testing[J]. J Mol Diagn, 2023, 25(4): 234-246. DOI: 10.1016/j.jmoldx.2023.01.006.
[25] 廖子珩. 面向新一代測序數(shù)據(jù)的拷貝數(shù)變異及其邊界的綜合檢測方法[D]. 西安: 西安電子科技大學(xué), 2022.
LIAO Z H. A comprehensive detection method for copy number variations and their boundaries for next-generation sequencing data[D]. Xi’an: Xi’an University of Electronic Science and Technology, 2022.
[26] MOGOS R A, POPOVICI R, TANASE A E, et al. New approaches in ovarian cancer based on genetics and carcinogenesis hypotheses (Review)[J]. Exp Ther Med, 2022, 23(6): 423. DOI: 10.3892/etm.2022.11351.
[27] REID BRETT M, PERMUTH JENNIFER B, ANN C Y, et al. Genome-wide analysis of common copy number variation and epithelial ovarian cancer risk[J]. Cancer Epidemiol Biomark Prev, 2019, 28(7): 1117-1126. DOI: 10.1158/1055-9965.EPI-18-0833.
[28] LOYER P, TREMBLEY J H. Roles of CDK/Cyclin complexes in transcription and pre-mRNA splicing: Cyclins L and CDK11 at the cross-roads of cell cycle and regulation of gene expression[J].
Semin Cell Dev Biol, 2020, 107: 36-45. DOI: 10.1016/j.semcdb.2020.04.016.
[29] HAKKAART C, PEARSON J F, MARQUART L, et al. Copy number variants as modifiers of breast cancer risk for BRCA1/BRCA2 pathogenic variant carriers[J]. Commun Biol, 2022,
5(1): 1061. DOI: 10.1038/s42003-022-03978-6.
[30] DEVRIES A A, DENNIS J, TYRER J P, et al. Copy number variants are ovarian cancer risk alleles at known and novel risk loci[J]. J Natl Cancer Inst, 2022, 114(11): 1533-1544. DOI: 10.1093/jnci/djac160.
[31] AGIANNITOPOULOS K, PEPE G, TSAOUSIS G N, et al. Copy number variations (CNVs) account for 10.8% of pathogenic variants in patients referred for hereditary cancer testing[J]. Cancer Genomics Proteomics, 2023, 20(5): 448-455. DOI: 10.21873/cgp.20396.
[32] BERKEL C, CACAN E. Differential expression and copy number variation of gasdermin (GSDM) family members, pore-forming proteins in pyroptosis, in normal and malignant serous ovarian tissue[J]. Inflammation, 2021, 44(6): 2203-2216. DOI: 10.1007/s10753-021-01493-0.
[33] KOTNIK E N, MULLEN M M, SPIES N C, et al. Genetic characterization of primary and metastatic high-grade serous ovarian cancer tumors reveals distinct features associated with survival[J]. Commun Biol, 2023, 6(1): 688. DOI: 10.1038/s42003-023-05026-3.
[34] BAN D, HOUSLEY S N, MCDONALD J F. The clinical significance of genetic variation in ovarian cancer[J]. Int J Mol Sci, 2023, 24(13): 10823. DOI: 10.3390/ijms241310823.
[35] ZHENG M, HU Y, GOU R, et al. Identification three LncRNA prognostic signature of ovarian cancer based on genome-wide copy number variation[J]. Biomedecine Pharmacother, 2020, 124: 109810. DOI: 10.1016/j.biopha.2019.109810.
[36] GARCíA-PARDO M, MAKAREM M, LI J J N, et al. Integrating circulating-free DNA (cfDNA) analysis into clinical practice: opportunities and challenges[J]. Br J Cancer, 2022, 127(4): 592-602. DOI: 10.1038/s41416-022-01776-9.
[37] CHEN L, MA R, LUO C, et al. Noninvasive early differential diagnosis and progression monitoring of ovarian cancer using the copy number alterations of plasma cell-free DNA[J]. Transl Res, 2023, 262: 12-24. DOI: 10.1016/j.trsl.2023.07.005.
[38] ZHANG M, CHENG S, JIN Y, et al. Roles of CA125 in diagnosis, prediction, and oncogenesis of ovarian cancer[J]. Biochim Biophys Acta Rev Cancer, 2021, 1875(2): 188503. DOI: 10.1016/j.bbcan.2021.188503.
[39] XIAO Y, BI M, GUO H, et al. Multi-omics approaches for biomarker discovery in early ovarian cancer diagnosis[J]. EBioMedicine, 2022, 79: 104001. DOI: 10.1016/j.ebiom.
2022.104001.
[40] MATULONIS U A, SOOD A K, FALLOWFIELD L, et al. Ovarian cancer[J]. Nat Rev Dis Primers, 2016, 2: 16061. DOI: 10.1038/nrdp.2016.61.
[41] ESPLEN H P, YANG R K, KALIA A, et al. Recurrent somatic copy number alterations and their association with oncogene expression levels in high-grade ovarian serous carcinoma[J]. Life, 2023, 13(11): 2192. DOI: 10.3390/life13112192.
[42] CHAN A M, ENWERE E, MCINTYRE J B, et al. Combined CCNE1 high-level amplification and overexpression is associated with unfavourable outcome in tubo-ovarian high-grade serous carcinoma[J]. J Pathol Clin Res, 2020, 6(4): 252-262. DOI: 10.1002/cjp2.168.
[43] PESENTI C, BELTRAME L, VELLE A, et al. Copy number alterations in stage I epithelial ovarian cancer highlight three genomic patterns associated with prognosis[J]. Eur J Cancer, 2022, 171: 85-95. DOI: 10.1016/j.ejca.2022.05.005.
[44] ADAMSON A W, DING Y C, STEELE L, et al. Genomic analyses of germline and somatic variation in high-grade serous ovarian cancer[J]. J Ovarian Res, 2023, 16(1): 141. DOI: 10.1186/s13048-023-01234-x.
[45] WU Z, LI S, TANG X, et al. Copy number amplification of DNA damage repair pathways potentiates therapeutic resistance in cancer[J]. Theranostics, 2020, 10(9): 3939-3951. DOI: 10.7150/thno.39341.
[46] JAMALZADEH S, DAI J, LAVIKKA K, et al. Genome-wide quantification of copy-number aberration impact on gene expression in ovarian high-grade serous carcinoma[J]. BMC Cancer, 2024, 24(1): 173. DOI: 10.1186/s12885-024-11895-6.
[47] GRAF R P, ESKANDER R, BRUEGGEMAN L, et al. Association of copy number variation signature and survival in patients with serous ovarian cancer[J]. JAMA Netw Open, 2021, 4(6): e2114162. DOI: 10.1001/jamanetworkopen.2021.14162.
[48] BERKEL C, CACAN E. Copy number and expression of CEP89, a protein required for ciliogenesis, are increased and predict poor prognosis in patients with ovarian cancer[J]. Cell Biochem Funct, 2022, 40(3): 298-309. DOI: 10.1002/cbf.3694.
(責(zé)任編輯:林燕薇)