[Proteomic analysis of lacrimal gland adenoid cystic carcinoma with high-grade transformation].

Objective: To analyze the protein expression differences of lacrimal gland adenoid cystic carcinoma (LACC) with high-grade transformation (HGT). Methods: Experimental study. A total of 8 paraffin tissue samples were collected in Tianjin Medical University Eye Hospital from December 2012 to January 2019. According to pathological examination, the samples were divided into the LACC group and the LACC-HGT group, with 4 cases in each group. The LACC group included 2 male samples and 2 female samples, with an average age of 53 years. The LACC-HGT group included 2 male samples and 2 female samples, with an average age of 44 years. Primary cells were cultured from fresh tumor tissue. Isobaric tags for relative and absolute quantification techniques were used to screen the differentially expressed proteins between the two groups, and bioinformatics analysis was conducted for the differentially expressed proteins. Microarray was used to screen differentially expressed mRNAs between LACC and LACC-HGT primary cells. The mass spectrum data were intersected with mRNA microarray data, and quantitative real-time (qRT) PCR was performed to verify the results. Proteomics and microarray data were compared using the independent sample t test. The qRT-PCR data were compared pairwise by one-way analysis of variance. Results: A total of 105 HGT-related differential proteins were detected in this study, including 50 up-regulated proteins and 55 down-regulated proteins. The significantly up-regulated proteins included hemoglobin subunit beta, hemoglobin subunit alpha 1, and collagen type Ⅵ alpha 2 chain; the significantly down-regulated proteins included Cereblon, adenosylhomocysteinase like 2, and ribosomal protein L39 pseudogene 5. Gene ontology analysis results showed that the LACC-HGT differential proteins were mainly located in the cytoplasm, vesicle cavity, and extracellular matrix, had organic acid binding and molecular carrier activity, and participated in the regulation of extracellular matrix composition, immunity, inflammation, apoptosis, and other biological processes. Pathway analysis showed that the LACC-HGT differential proteins were mainly involved in signal pathways such as mitogen-activated protein kinase signal pathway and extracellular matrix proteoglycans and glycan metabolism signal pathway. Protein complex prediction analysis screened out 4 up-regulated protein complexes and 1 down-regulated protein complex. There were 15 LACC-HGT differential proteins that overlapped with mRNA chip differential genes, of which 6 were tumor-related proteins including collagen type XIV alpha 1 chain (COL14A1), EMAP like 4 (EML4), inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), NDRG family member 2 (NDRG2), osteoglycin (OGN) an Ras homolog family member C (RhoC). The main function was the movement and migration of tumor cells. The qRT-PCR results showed that the relative expression levels of COL14A1, EML4, ITIH4, NDRG2, OGN, and RhoC in primary LACC-1, LACC-2, LACC-HGT-1, and LACC-HGT-2 cells were significantly different (F=1 675.98, 38.53, 27.37, 16.47, 13.38, 25.22, all P<0.01). For example, the relative expression of COL14A1 in primary LACC-HGT-1 (16.09±0.51) and LACC-HGT-2 (9.96±0.34) cells was significantly higher than that in primary LACC-1 (1.00±0.13) and LACC-2 (0.67±0.08) cells (all P<0.05). Conclusion: There are differentially expressed proteins between LACC-HGT and LACC, among which COL14A1, EML4, ITIH4, NDRG2, OGN, and RhoC may play an important role in LACC-HGT and can be used as potential targets of LACC-HGT in further study. (Chin J Ophthalmol, 2021, 57: 531-539).目的： 分析泪腺腺样囊腺癌（LACC）高级别转化（HGT）的蛋白表达差异。 方法： 实验研究。收集2012年12月至2019年1月在天津医科大学眼科医院就诊的8例LACC患者的石蜡组织样本。根据组织病理学检查结果，分为LACC组和LACC-HGT组，每组4例，男性和女性各2例；平均年龄分别为53、44岁。采用同位素相对标记与绝对定量技术筛选两组石蜡组织样本的差异蛋白，对差异蛋白进行生物信息学分析。运用新鲜组织块培养法进行原代细胞培养，运用基因芯片筛选LACC与LACC-HGT原代细胞之间差异表达的mRNA。将质谱数据与mRNA芯片数据取交集，并进行实时荧光定量PCR验证。蛋白组学和基因芯片数据的比较采用独立样本t检验；PCR数据比较采用单因素方差分析。 结果： 共检测到HGT相关差异蛋白105个，包括50个上调蛋白和55个下调蛋白。显著上调的蛋白有血红蛋白、糖化血红蛋白和Ⅵ型胶原蛋白2等；显著下调的蛋白有Cereblon蛋白、S-腺苷同型半胱氨酸水解酶样蛋白2和核糖体蛋白L39等。基因本体分析结果表明，LACC-HGT差异蛋白主要定位于细胞质、囊泡腔、细胞外基质，具有有机酸结合、分子载体活性等，参与调控细胞外基质组成、免疫、炎性反应及凋亡等生物学过程。通路富集分析显示，LACC-HGT差异蛋白主要参与丝裂原活化蛋白激酶、细胞外基质-蛋白聚糖及聚糖代谢等信号通路。蛋白复合体预测分析筛选出4个上调的蛋白复合体和1个下调的蛋白复合体。LACC-HGT差异蛋白与mRNA芯片差异基因重合的共15个，其中肿瘤相关蛋白6个包括XIV型胶原蛋白1 （COL14A1）、棘皮微管相关蛋白4（EML4）、α-胰蛋白酶抑制因子（ITIH4）、N-myc下游调控基因2 （NDRG2）、骨诱导因子（OGN）、RAS同源基因家族C（RhoC）。主要功能涉及肿瘤细胞的运动和迁移等。PCR结果表明，COL14A1、EML4、ITIH4、NDRG2、OGN、RhoC在LACC-1、LACC-2、LACC-HGT-1和LACC-HGT-2原代细胞中的相对表达量差异有统计学意义（F=1 675.98，38.53，27.37，16.47，13.38，25.22；均P<0.01），如COL14A1在LACC-HGT-1和LACC-HGT-2原代细胞中的相对表达量（16.09±0.51、9.96±0.34）均显著高于LACC-1原代细胞（1.00±0.13）和LACC-2（0.67±0.08）（均P<0.05）。 结论： LACC-HGT与LACC之间存在差异表达蛋白，其中COL14A1、EML4、ITIH4、NDRG2、OGN、RhoC可能在LACC的高级别转化过程中具有重要意义，可作为LACC-HGT的潜在靶点进行深入研究。（中华眼科杂志，2021，57：531-539）.