[摘要] 目的
基于相關數(shù)據(jù)庫分析篩選肝細胞癌(HCC)脂質(zhì)代謝相關轉(zhuǎn)移風險基因,并聯(lián)合其他臨床危險因素構建患者的預后預測模型。
方法 應用R軟件從GEO數(shù)據(jù)庫中獲得原發(fā)性和轉(zhuǎn)移性HCC患者的差異表達基因(DEGs),并篩選與患者預后相關的DEGs。將TCGA數(shù)據(jù)庫中的HCC患者通過層次聚類分為兩組,評估兩組患者EMT評分、脂質(zhì)代謝水平和預后。應用ICGC數(shù)據(jù)庫中的數(shù)據(jù)再次對上述分析進行驗證。應用LASSO回歸模型篩選脂質(zhì)代謝相關轉(zhuǎn)移風險基因并進行風險評分,通過風險評分中位數(shù)分別將TCGA和ICGC數(shù)據(jù)庫中HCC患者分為高、低危組,并分析患者的預后。應用單因素和多因素Cox回歸分析獲得影響HCC患者預后的獨立危險因素,并構建列線圖預后模型。采用Western blot和油紅O染色檢測應用脂質(zhì)代謝抑制劑Fatostatin后Huh7細胞脂質(zhì)代謝的情況;采用qPCR技術檢測Huh7細胞中脂質(zhì)代謝相關轉(zhuǎn)移風險基因表達水平。
結(jié)果 從GEO數(shù)據(jù)庫中獲得原發(fā)性和轉(zhuǎn)移性HCC患者的DEGs共159個,其中65個DEGs與HCC患者的OS顯著相關。通過EMT評分將TCGA數(shù)據(jù)庫中聚類所得的兩組HCC患者分別定義為高、低轉(zhuǎn)移風險組。高轉(zhuǎn)移風險組患者脂質(zhì)代謝評分更高,OS更短。在ICGC數(shù)據(jù)庫中驗證的結(jié)果與TCGA數(shù)據(jù)庫一致。應用LASSO回歸模型篩選出脂質(zhì)代謝相關轉(zhuǎn)移風險基因,高危組OS更短。將脂質(zhì)代謝相關轉(zhuǎn)移風險基因與影響HCC患者預后的獨立危險因素相結(jié)合,構建預后預測列線圖模型。細胞實驗證實,應用Fatostatin后,Huh7細胞的脂肪酸合酶表達降低,細胞內(nèi)脂滴含量減少,多種脂質(zhì)代謝相關轉(zhuǎn)移風險基因表達發(fā)生變化。
結(jié)論 基于數(shù)據(jù)庫分析獲得了13個脂質(zhì)代謝相關轉(zhuǎn)移風險基因,將這些基因和臨床危險因素聯(lián)合構建了HCC患者的預后預測模型,并通過細胞實驗初步驗證了脂質(zhì)代謝相關轉(zhuǎn)移風險基因與脂質(zhì)代謝密切相關。
[關鍵詞] 癌,肝細胞;腫瘤轉(zhuǎn)移;脂類代謝;基因表達;數(shù)據(jù)庫,遺傳學;預后
[中圖分類號] R735.7;R394
[文獻標志碼] A
Construction of a predictive model for the prognosis of patients with hepatocellular carcinoma based on lipid metabolism-related metastasis risk genes
HE Mingyang, ZHANG Xuhui, WANG Yunhan, ZHAO Zi-yin, GUAN Ge, HAN Bing, ZHANG Bin
(Organ Transplantation Center, The Affiliated Hospital of Qingdao University, Qingdao 266100, China)
; [ABSTRACT]\ Objective To identify the lipid metabolism-related metastasis risk genes for hepatocellular carcinoma (HCC) based on related databases, and to construct a predictive model for the prognosis of HCC patients in combination with other clinical risk factors.
Methods R software was used to obtain the differentially expressed genes (DEGs) between the patients with primary HCC and those with metastatic HCC from the GEO database, and the DEGs associated with the prognosis of patients were identified. The HCC patients in TCGA database were divided into two groups based on hierarchical clustering, and the two groups were assessed in terms of epithelial-mesenchymal transition (EMT), lipid metabolism, and prognosis. The data in the ICGC database were used for validation of the above analysis. The LASSO regression model was used to obtain the lipid metabolism-related metastasis risk genes and determine their risk scores, and according to the median of risk scores, HCC patients in both TCGA and ICGC databases were divided into high and low risk groups to analyze the prognosis of patients. Univariate and multivariate Cox regression analyses were used to obtain independent risk factors for the prognosis of HCC patients, and a nomogram prognostic model was constructed. Western blot and oil red O staining were used to detect the lipid metabolism of Huh7 cells after treatment with the lipid metabolism inhibitor Fatostatin, and qPCR was used to measure the expression levels of lipid metabolism-related metastasis risk genes in Huh7 cells.
Results A total of 159 DEGs were obtained from the patients with primary HCC and those with metastatic HCC in the GEO database, among which 65 DEGs were significantly associated with the overall survival (OS) of HCC patients. Based on the EMT score, the two groups of HCC patients obtained by clustering from the TCGA database were defined as high and low metastasis risk groups, respectively, and the patients in the high metastasis risk group tended to have a higher lipid metabolism score and a shorter OS. The validation results in the ICGC database were consistent with the results based on the TCGA database. The LASSO regression model was used to identify the lipid metabolism-related metastasis risk genes, and the high-risk group had a shorter OS. The lipid metabolism-related metastasis risk genes were combined with the independent risk factors for the prognosis of patients with HCC to construct a nomogram prognostic model. Cell experiments confirmed that after the treatment with Fatostatin, there were reductions in the expression of fatty acid synthase and the content of lipid droplets in Huh7 cells, as well as changes in the expression of a variety of lipid metabolism-related metastasis risk genes.
Conclusion A total of 13 lipid metabolism-related metastasis risk genes are obtained based on related databases, which are combined with the clinical risk factors to construct a prognostic predictive model for HCC patients, and cell experiments are conducted to confirm that the lipid metabolism-related metastasis risk genes are closely associated with lipid metabolism.
[KEY WORDS] Carcinoma, hepatocellular; Neoplasm metastasis; Lipid metabolism; Gene expression; Databases, genetic; Prognosis
肝細胞癌(hepatocellular carcinoma,HCC)是最常見的肝癌類型,約占肝癌患者的90%。手術切除后腫瘤的高復發(fā)率和高轉(zhuǎn)移率是影響HCC預后的主要因素[1]。肝癌肝外轉(zhuǎn)移(EHM)在初診時相對少見,發(fā)生EHM的患者一般預后較差[2-4]。目前研究認為,脂質(zhì)代謝紊亂是HCC的重要驅(qū)動因素之一[5],而且脂質(zhì)代謝紊亂與上皮-間充質(zhì)轉(zhuǎn)化(EMT)密切相關[6-7],脂肪酸合成酶(FASN)升高預示著HCC患者的預后不良[8]。近些年與HCC的轉(zhuǎn)移相關的基因已得到廣泛研究[9-10],關于HCC的脂質(zhì)代謝相關基因的研究也已見報道[11]。然而,HCC中同時與轉(zhuǎn)移和脂質(zhì)代謝密切相關的基因卻鮮有研究報道。
本研究基于基因表達數(shù)據(jù)庫(GEO)、癌癥基因組圖譜(TCGA)和國際癌癥基因組聯(lián)盟(ICGC)數(shù)據(jù)庫分析獲得HCC中同時與轉(zhuǎn)移和脂質(zhì)代謝密切相關的基因(本研究稱之為脂質(zhì)代謝相關轉(zhuǎn)移風險基因),并將這些基因和臨床危險因素聯(lián)合構建了HCC患者的預后預測模型;同時通過細胞實驗,以檢測脂質(zhì)代謝相關轉(zhuǎn)移風險基因在Huh7細胞中的表達情況,驗證生物信息學的分析結(jié)果。旨在為尋找HCC新的預測指標提供研究思路和數(shù)據(jù)參考。
1 材料與方法
1.1 TCGA數(shù)據(jù)庫中HCC患者的EMT及脂質(zhì)代謝評分及預后分析
采用R軟件從GEO數(shù)據(jù)庫(https://www.ncbi.nlm.nih.gov/geo/)中篩選原發(fā)性與轉(zhuǎn)移性HCC患者腫瘤組織的差異表達基因(DEGs)。從TCGA數(shù)據(jù)庫(https://portal.gdc.cancer.gov/)當中下載HCC患者的RNA測序數(shù)據(jù)以及患者的臨床相關信息,采用單因素Cox回歸分析DEGs與患者總生存期(OS)的相關性。
使用無監(jiān)督層次聚類方法依據(jù)上面分析獲得的DEGs表達水平,將TCGA數(shù)據(jù)庫中HCC患者分為兩組,采用如下3種方法針對兩組HCC患者的EMT進行評分:①基于17個EMT標志基因計算EMT評分[12];②基于最小絕對收縮和選擇算子(LASSO) Cox回歸模型中基因表達水平及其系數(shù)進行EMT評分[13];③采用單樣本基因集富集分析(ssGSEA)方法,使用基因本體(GO)數(shù)據(jù)庫中EMT相關基因集對樣本進行EMT評分[14],每組患者均獲得3個EMT評分,比較兩組患者同一種方法獲得的EMT評分是否有差異。EMT評分較高的組定義為高轉(zhuǎn)移風險組,評分較低的組定義為低轉(zhuǎn)移風險組,采用R軟件篩選兩組患者HCC組織的DEGs,采用Kaplan-Meier(K-M)生存曲線分析比較兩組患者的預后。
對篩選出來的高、低轉(zhuǎn)移風險組DEGs,使用R軟件進行KEGG和GO分析。依據(jù)當前的相關研究文獻,獲得3組脂質(zhì)代謝相關基因[15-17],通過GSVA軟件包對每一個脂質(zhì)代謝相關基因進行ssGSEA分析后,將3組基因合并為一組,再應用R軟件進行LASSO Cox回歸分析,獲得TCGA數(shù)據(jù)庫中每例HCC患者的脂質(zhì)代謝評分,比較高、低轉(zhuǎn)移風險組患者脂質(zhì)代謝評分的差異。根據(jù)脂質(zhì)代謝評分的中位數(shù),將患者分為高、低脂質(zhì)代謝組,采用Kaplan-Meier(K-M)生存曲線分析并比較兩組患者的預后。
1.2 ICGC數(shù)據(jù)庫驗證
對ICGC數(shù)據(jù)庫(https://dcc.icgc.org)中的HCC患者數(shù)據(jù),采用無監(jiān)督層次聚類方法,依據(jù)原發(fā)性和轉(zhuǎn)移性HCC患者的DEGs表達水平,分為兩組,采用上述的脂質(zhì)代謝評分方法對兩組患者進行脂質(zhì)代謝評分,評分較高的組為高脂質(zhì)代謝組,評分較低的組為低脂質(zhì)代謝組。然后,采用上述EMT評分方法③,分別計算高脂質(zhì)代謝組和低脂質(zhì)代謝組EMT評分,比較兩組患者的EMT評分是否有差異。采用K-M生存曲線分析比較兩組患者預后。
1.3 脂質(zhì)代謝相關轉(zhuǎn)移風險基因標簽和預后預測列線圖模型的構建
在TCGA數(shù)據(jù)庫中,對高、低轉(zhuǎn)移風險組患者的DEGs進行LASSO回歸分析,同時代入患者的EMT評分、脂質(zhì)代謝評分以及K-M生存曲線分析結(jié)果,篩選與預后密切相關DEGs,即為脂質(zhì)代謝相關轉(zhuǎn)移風險基因。根據(jù)LASSO回歸分析中對脂質(zhì)代謝相關轉(zhuǎn)移風險基因的賦值,構建脂質(zhì)代謝相關轉(zhuǎn)移風險基因的風險評分模型,計算TCGA、ICGC數(shù)據(jù)庫中每例HCC患者的風險評分。
根據(jù)風險評分中位數(shù)將TCGA數(shù)據(jù)庫(訓練集)中的HCC患者分為高危組和低危組,將ICGC數(shù)據(jù)庫(驗證集)中的HCC患者也分為高危組和低危組。采用K-M生存曲線分析比較上述兩個數(shù)據(jù)庫兩組患者的預后。
采用單因素和多因素Cox回歸分析TCGA數(shù)據(jù)庫中影響HCC患者預后的獨立危險因素,將脂質(zhì)代謝相關轉(zhuǎn)移風險基因與多因素Cox回歸分析結(jié)果相結(jié)合,構建HCC患者的預后列線圖模型。繪制TCGA數(shù)據(jù)庫當中1、3、5年患者生存率的受試者工作特征(ROC)曲線,同時計算曲線下面積(AUC),繪制ICGC數(shù)據(jù)庫中1、3年患者生存率的ROC曲線,并計算其AUC,評估預后列線圖模型的預測能力。
1.4 Huh7細胞中脂質(zhì)代謝相關轉(zhuǎn)移風險基因的表達情況
人肝癌Huh7細胞系購自中科院上海細胞庫。將Huh7細胞置于含有10% FBS和1%青/鏈霉素的DMEM培養(yǎng)基中,于37 ℃、含體積分數(shù)0.05 CO2的條件下進行培養(yǎng),待細胞密度達70%~80%時將細胞分為4組,培養(yǎng)基中分別加入0、10、20、30 μmol/L濃度的Fatostatin,繼續(xù)培養(yǎng)24 h。使用Western blot方法[18]檢測各組細胞中FASN的相對表達量,確定后續(xù)最佳給藥濃度。在細胞密度達70%~80%時將Huh7細胞分為對照組和給藥組,分別加入0、20 μmol/L濃度的Fatostatin,繼續(xù)培養(yǎng)24 h。使用油紅O染色試劑盒(北京索萊寶科技有限公司)檢測兩組Huh7細胞中的脂滴含量。使用qPCR方法檢測兩組Huh7細胞中脂質(zhì)代謝相關轉(zhuǎn)移風險基因的相對表達量。上述步驟均嚴格按照各試劑盒的說明書進行操作。
1.5 統(tǒng)計學分析
使用R軟件(R版本4.1.2)和GraphPad Prism 8軟件進行統(tǒng)計學分析。使用K-M曲線進行患者生存分析。計量資料多組間比較采用方差分析,進一步兩兩比較采用t檢驗;兩組間比較采用t檢驗或秩合檢驗。以Plt;0.05為差異有統(tǒng)計學意義。
2 結(jié)" 果
2.1 轉(zhuǎn)移相關亞型的聚類和脂質(zhì)代謝水平評估
GEO數(shù)據(jù)庫分析結(jié)果顯示,原發(fā)性與轉(zhuǎn)移性HCC的DEGs共有159個;TCGA數(shù)據(jù)庫分析結(jié)果顯示,其中有65個DEGs與HCC患者的OS顯著相關(Plt;0.05)。在TCGA數(shù)據(jù)庫中經(jīng)無監(jiān)督層次聚類方法獲得的兩組HCC患者進行3種方法的EMT評分,結(jié)果顯示,兩組患者經(jīng)方法①~③獲得的EMT評分比較差異均有顯著性(t=5.75~8.24,Plt;0.05)。見表1。K-M生存曲線分析顯示,高轉(zhuǎn)移風險組比低轉(zhuǎn)移風險組患者的OS更短(Plt;0.05);高、低轉(zhuǎn)移風險組患者HCC組織的DEGs共有107個。
對高、低轉(zhuǎn)移風險組的DEGs進行GO分析,結(jié)果顯示,兩組患者的DEGs在類固醇代謝過程、脂肪酸代謝過程以及蛋白質(zhì)-脂質(zhì)復合物當中顯著富集;KEGG分析結(jié)果顯示,這些DEGs在藥物代謝-細胞色素P450、膽固醇代謝和脂肪酸降解中顯著富集。高、低轉(zhuǎn)移風險組患者的脂質(zhì)代謝評分則分別為(12.90±1.17)、(12.56±1.04)分。高轉(zhuǎn)移風險組患者的脂質(zhì)代謝評分顯著性高于低轉(zhuǎn)移風險組(t=2.87,Plt;0.05);K-M生存曲線分析顯示,高轉(zhuǎn)移風險組患者的OS顯著短于低轉(zhuǎn)移風險組(Plt;0.05)。
2.2 基于ICGC數(shù)據(jù)庫中HCC數(shù)據(jù)集的驗證
高、低脂質(zhì)代謝組患者的EMT評分分別為1.81(-0.95,8.42)、0.78(-5.68,5.52)分,兩組比較差異有顯著統(tǒng)計學意義(Z=2.73,Plt;0.05)。K-M生存曲線分析顯示,高脂質(zhì)代謝組患者的OS顯著短于低脂質(zhì)代謝組(Plt;0.05)。
2.3 脂質(zhì)代謝相關轉(zhuǎn)移風險基因的篩選和預后列線圖模型的構建
LASSO回歸分析結(jié)果顯示,在TCGA數(shù)據(jù)庫中篩選出13個脂質(zhì)代謝相關轉(zhuǎn)移風險基因,分別為
ACOT12、BSG、ERP29、LAGE3、MRPL54、PIGU、POLE4、PPM1G、PRAF2、SNX7、TDRD6、UBE2S和UGP2,
以此為基礎構建的脂質(zhì)代謝相關轉(zhuǎn)移風險基因風險評分模型為:風險評分=ACOT12×
(-0.015 419 894)+BSG×0.030 955 454+ERP29×
0.017 152 934+LAGE3×0.021 491 424+MRPL54×
(-0.245 091 708)+PIGU×0.232 450 448+POLE4×
0.049 859 444+PPM1G×0.171 847 45+
PRAF2×0.074 382 102+SNX7×0.070 771 486+TDRD6×
0.082 766 628+UBE2S×0.050 119 927+
UGP2×(-0.014 147 443)。在TCGA數(shù)據(jù)庫中高、低危組患者EMT評分分別為(2.40±0.34)、(1.66±0.30)分,兩組比較差異具有顯著意義(t=20.47,Plt;0.05);ICGC數(shù)據(jù)庫中,高、低危組患者的EMT評分分別為(2.25±0.24)、(1.58±0.24)分,兩組比較差異有顯著性(t=21.09,Plt;0.05)。K-M生存曲線分析顯示,在TCGA、ICGC數(shù)據(jù)庫中,高危組患者的OS均顯著短于低危組(Plt;0.05)。
單因素和多因素Cox分析顯示,脂質(zhì)代謝相關轉(zhuǎn)移風險基因以及患者的年齡、腫瘤分期和血管侵犯是影響HCC患者OS的獨立危險因素。將上面分析獲得的獨立危險因素構建HCC患者預后列線圖模型,見圖1。在TCGA數(shù)據(jù)庫中,根據(jù)患者1、3、5年生存率的ROC曲線計算得到的AUC分別為0.75、0.69和0.67;在ICGC數(shù)據(jù)庫當中,根據(jù)患者1、3年生存率的ROC曲線計算得到的AUC分別為0.82以及0.78。
2.4 Huh7細胞中脂質(zhì)代謝相關轉(zhuǎn)移風險基因的表達情況
Western blot實驗的檢測結(jié)果顯示,0、10、20、30 μmol/L濃度的Fatostatin處理Huh7細胞24 h時,細胞中FASN相對表達量分別為1.09±0.00、0.94±0.01、0.61±0.01、0.66±0.01,各組間比較差異有顯著性(F=1 104.00,Plt;0.05),其他濃度組與0 μmol/L濃度組比較,均有顯著差異(t=16.52~60.12,Plt;0.05),其中20 μmol/L濃度時,Huh7細胞中FASN相對表達量最低,后續(xù)實驗采用的Fatostatin濃度為20 μmol/L。見圖2。油紅O染色結(jié)果顯示,對照組以及給藥組細胞脂滴含量分別為4 641.42±226.40、1 797.45±145.85,兩組比較差異有顯著性(t=14.93,Plt;0.05)。見圖3。
qPCR檢測的結(jié)果顯示,給藥組細胞中PIGU、PPM1G、PRAF2、TDRD6基因的相對表達量顯著低于對照組(t=4.39~8.46,Plt;0.05),ACOT12、UBE2S基因的相對表達量均顯著高于對照組(t=3.16、3.46,Plt;0.05),兩組細胞中BSG、MRPL54基因相對表達量比較,差異無顯著統(tǒng)計學意義(P>0.05)。見表2。
3 討" 論
HCC是最常見的肝癌類型,轉(zhuǎn)移率較高,其轉(zhuǎn)移可分為肝內(nèi)轉(zhuǎn)移和EHM[19]。肝內(nèi)轉(zhuǎn)移通常是指癌細胞直接侵襲、遷移或癌栓脫落形成轉(zhuǎn)移病灶;EHM則包括血行轉(zhuǎn)移、淋巴轉(zhuǎn)移及種植轉(zhuǎn)移,轉(zhuǎn)移灶可出現(xiàn)在全身多處組織和臟器[20]。HCC患者一旦發(fā)生EHM,通常預后較差。早期識別EHM高?;颊卟@EHM進行治療可顯著提高患者生存率[21]。脂質(zhì)是維持細胞骨架結(jié)構、儲存和產(chǎn)生能量
的必需物質(zhì),并參與許多重要信號通路的轉(zhuǎn)導[22-23]。
脂質(zhì)代謝重編程是癌癥進展的標志之一[24]。EMT可增強癌細胞遷移和侵襲能力,因此通常為腫瘤轉(zhuǎn)移的主要驅(qū)動因素之一[25]。越來越多的證據(jù)表明,脂質(zhì)代謝是EMT的重要調(diào)控因素,與腫瘤的轉(zhuǎn)移密切相關[26]。
本研究首先從GEO數(shù)據(jù)庫中分析獲得原發(fā)性和轉(zhuǎn)移性HCC的DEGs,根據(jù)這些DEGs,將TCGA數(shù)據(jù)庫中的HCC患者進行聚類并分為兩組,使用3種方法對兩組患者進行EMT評分,結(jié)果兩組患者的EMT評分均有顯著差異;相較于高轉(zhuǎn)移風險組,低轉(zhuǎn)移風險組患者OS更長;且高轉(zhuǎn)移風險組的脂質(zhì)代謝評分顯著高于低轉(zhuǎn)移風險組。進一步GO、KEGG分析顯示,這些DEGs均與脂質(zhì)代謝途徑密切相關。綜合上面的分析結(jié)果,提示脂質(zhì)代謝與HCC患者轉(zhuǎn)移和不良預后密切相關。然后,本研究在ICGC數(shù)據(jù)庫中,按照TCGA數(shù)據(jù)庫的分析方法反向驗證,結(jié)果與TCGA數(shù)據(jù)庫的分析結(jié)果一致,說明該分析方法和獲得的結(jié)果是可靠的。
進一步應用LASSO回歸分析,在TCGA數(shù)據(jù)庫中篩選出13個脂質(zhì)代謝相關轉(zhuǎn)移風險基因,并構建了脂質(zhì)代謝相關轉(zhuǎn)移風險基因的風險評分模型。通過該模型首先對TCGA數(shù)據(jù)庫中HCC患者進行風險評分,并分為高、低危組,兩組患者的脂質(zhì)代謝評分差異有顯著性,高危組患者的OS均顯著短于低危組。同樣在ICGC數(shù)據(jù)庫中進行驗證,結(jié)果仍然是高危組患者的OS均顯著短于低危組。說明本研究的脂質(zhì)代謝相關轉(zhuǎn)移風險基因的風險評分模型構建成功。基于單因素和多因素Cox回歸分析的結(jié)果,將脂質(zhì)代謝相關轉(zhuǎn)移風險基因與患者的年齡、腫瘤分期、血管侵犯等預后臨床特征相結(jié)合,構建了HCC患者的列線圖預后預測模型。ROC曲線顯示模型的預測性能良好。
本研究又通過細胞實驗,對上面分析獲得的結(jié)果進行了驗證。本研究首先篩選了脂質(zhì)代謝抑制劑Fatostatin處理人肝癌Huh7細胞的最適宜濃度,Western blot實驗結(jié)果顯示,使用20 μmol/L濃度Fatostatin處理Huh7細胞時,F(xiàn)ASN的相對表達量最低,所以選擇該濃度組進行后續(xù)實驗。FASN是脂質(zhì)代謝途徑中的關鍵酶,能夠調(diào)節(jié)細胞內(nèi)脂肪酸的合成,因此可以作為反映細胞內(nèi)脂質(zhì)代謝活躍程度的指標。油紅O染色結(jié)果顯示,與對照組相比,給藥組細胞的脂滴含量顯著降低,說明Fatostatin抑制了Huh7細胞的脂質(zhì)代謝。qPCR檢測的結(jié)果顯示,抑制脂質(zhì)代謝以后,Huh7細胞當中PIGU、PPM1G、PRAF2以及TDRD6的表達顯著降低,ACOT12和UBE2S的表達顯著升高,BSG和MRPL54的表達無顯著變化。提示這些基因可能位于FASN的下游并參與調(diào)節(jié)細胞脂質(zhì)代謝。表達下調(diào)的4個基因(PIGU、PPM1G、PRAF2和TDRD6)可能具有促進脂肪酸合成的功能,并可能參與了肝癌EHM的發(fā)生。PIGU與代謝相關,其可通過激活NF-κB通路,增強免疫逃逸,促進HCC進展,并可作為HCC預后分層的標志物[27]。PPM1G可通過調(diào)控選擇性剪接蛋白SRSF3的磷酸化促進HCC的進展,并且PPM1G在HCC中高表達與患者不良預后相關[28]。PRAF2高表達提示肝癌患者預后不良[29]。TDRD6在HCC中的作用尚未見有相關報道。
綜上所述,本研究通過對多個數(shù)據(jù)庫進行一系列生物信息學分析,獲得了13個脂質(zhì)代謝相關轉(zhuǎn)移風險基因,可能是早期識別EHM高?;颊叩挠行飿酥疚?;并將這些基因和臨床危險因素聯(lián)合構建了HCC患者的預后模型。通過細胞實驗初步驗證了脂質(zhì)代謝相關轉(zhuǎn)移風險基因與脂質(zhì)代謝密切相關。但本研究僅僅是基于公共數(shù)據(jù)庫中的數(shù)據(jù)進行的分析,結(jié)果還需要更多的實驗研究進行驗證。
作者聲明:何明陽、趙梓吟、張斌參與了研究設計;何明陽、張旭輝、王蘊涵、關鴿、韓冰、張斌參與了論文的寫作和修改。所有作者均閱讀并同意發(fā)表該論文,且均聲明不存在利益沖突。
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(本文編輯 耿波)