研究對象：
分析檢測平臺：GC-TOF／MS和UHPLC-QqQ-MS（BIOTREE）
期刊：Tumor Biology
影響因子：2.926
發(fā)表時間：2016
 
摘要：
Abstract Papillary thyroid carcinoma (PTC) is the most common pathological type of thyroid cancer. Our study was to construct a tissue-targeted metabolomics analysis method based on untargeted and targeted metabolic multi-platforms to identify a comprehensive PTC metabolic network in clinical samples. We applied untargeted gas chromatography-time of-flight mass spectrometry (GC-TOF-MS) for preliminary screening of potential biomarkers. With diagnostic models constructed using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA), 45 differentially abundant metabolites with a variable importance in the projection (VIP) value greater than 1 and a P value less than 0.05 were identified, and we show that our approach was able to discriminate PTC tissues from healthy tissues. We then performed validation experiments based on targeted GCTOF-MS combined with ultra-high-performance liquid chromatography-triple-quadrupole mass spectrometry (UHPLC-q-MS) through constructing linear standard curves of analytes. Ultimately, galactinol, melibiose, and melatonin were validated as significantly altered metabolites (p <0.05). These three metabolites were defined as a combinatorial biomarker to assist needle biopsy for PTC diagnosis as demonstrated by receiver operating characteristic (ROC) curve analysis, which revealed an area under the ROC curve
(AUC) value of 0.96. Based on the metabolite enrichment analysis results, the galactose metabolism pathway was regarded as an important factor influencing PTC development by affecting energy metabolism. Alpha-galactosidase (GLA) was considered to be a potential target for PTC therapy.
 
一、研究背景：
甲狀腺腫瘤的發(fā)病率逐年升高，通過早期的診斷和治療可有效降低其復(fù)發(fā)率和致死率。目前甲狀腺腫瘤主要通過超聲和超聲介導(dǎo)的穿刺活體切片（FNAB）進(jìn)行診斷，但其特異性等仍有待提高。腫瘤生物標(biāo)志物可與FNAB方法結(jié)合使用，以更準(zhǔn)確地進(jìn)行惡性腫瘤診斷。乳突狀甲狀腺腫瘤（PTC）是常見的惡性甲狀腺腫瘤的亞型之一。如整合目前代謝組學(xué)研究中的非靶向（GC-TOF-MS）和靶向（UHPLC--MS）兩種研究平臺可更加高效和可靠地進(jìn)行潛在生物標(biāo)志物的篩選。

二、方法流程：
 

三、研究結(jié)果與討論：
1 不同組織代謝指紋圖譜：
1）檢測到686個內(nèi)源性代謝物峰
2）腫瘤組織和正常組織代謝物出現(xiàn)明顯區(qū)別
3）通過OPLS-DA模型篩選得到45個標(biāo)志性差異物
4）半乳糖代謝途徑在腫瘤組織中發(fā)生顯著改變
 
 
圖1非靶標(biāo)實驗結(jié)果
 
2 通過靶標(biāo)代謝組學(xué)對潛在生物標(biāo)志物的驗證
1）通過UHPLC-Q-MS對前期篩到的潛在標(biāo)志物通過標(biāo)準(zhǔn)曲線進(jìn)行精確定量，其中11個可測定；
2）精確定量物質(zhì)中，3個在前列腺腫瘤（PTC）中濃度高，8個在PTC中濃度低；
3）半乳糖代謝途徑上的代謝物經(jīng)過T檢驗表現(xiàn)出統(tǒng)計學(xué)顯著性差異
4）結(jié)合靶標(biāo)、非靶標(biāo)實驗確定的生物標(biāo)志物：肌醇半乳糖苷、蜜二糖、褪黑激素
 圖2 靶標(biāo)實驗獲得標(biāo)志性物質(zhì)獲得的ROC曲線3 PTC中代謝途徑的特征1） 乳糖代謝途徑減弱與PTC癌變過程可能有關(guān)2） PTC中褪黑激素含量降低，該物質(zhì)可能具有抑制腫瘤作用3） 不飽和脂肪酸合成途徑減弱可能與PTC發(fā)病相關(guān)

圖3結(jié)合非靶標(biāo)和靶標(biāo)代謝組學(xué)信息獲得的PTC可能相關(guān)途徑四、亮點和展望l 非靶標(biāo)代謝組學(xué)實驗之后用靶標(biāo)實驗對標(biāo)志性差異物進(jìn)行精確定量，為建立生物標(biāo)志物提供了更加堅實的基礎(chǔ)；

 通過靶標(biāo)實驗更精確地定位癌細(xì)胞中發(fā)生變化的代謝通路，為后續(xù)研究提供更可靠的線索
l 展望：針對精確定量得到的生物標(biāo)志物可通過大樣本進(jìn)行驗證和推進(jìn)
l 展望：針對乳糖代謝途徑進(jìn)行多角度研究，研究其細(xì)致的調(diào)節(jié)機制