Liu X Y, Yang Y, Yang C D, Ma Z X, Wu C H, Xu C, Zhu R, Liu P, Ying L S, Yin W J, Su D
The Second Clinical Medical College, Zhejiang Chinese Medicine University, Hangzhou310053, China.
Department of Pathology, Zhejiang Cancer Hospital, Institute of Basic Medicine and Cancer, Chinese Academy of Sciences, Hangzhou310022, China.
Zhonghua Zhong Liu Za Zhi. 2024 Nov 23;46(11):1029-1037. doi: 10.3760/cma.j.cn112152-20231024-00214.
To analyze the expression of FAT1 gene in pancreatic adenocarcinoma and its relationship with clinicopathological features, prognosis, and immunotherapy for pancreatic adenocarcinoma. (1) Bioinformatics analysis: based on FAT1 mRNA expression and clinical data of 179 cases of pancreatic adenocarcinoma in the TCGA database, and FAT1 mRNA expression data of 328 cases of normal pancreatic tissues in the GTEx database. We analyzed the differences in FAT1 mRNA expression in pancreatic adenocarcinoma and normal pancreatic tissues and the relationship between FAT1 mRNA expression and the degree of differentiation, clinical stage, prognosis, immune cell infiltration, and immune checkpoint-associated genes in pancreatic adenocarcinoma. FAT1-related differentially expressed genes were analyzed by applying Limma 3.40.2 software package, and GO and KEGG enrichment analysis was performed on the differentially expressed genes. Immunohistochemical (IHC) of FAT1 in pancreatic adenocarcinoma and normal pancreatic tissues was analyzed by HPA database. (2) Validation of own tissue samples: tissue samples and clinical and prognostic data of 192 patients with pancreatic ductal adenocarcinoma admitted to Zhejiang Cancer Hospital from March 8, 2010 to September 30, 2020 were collected. IHC was performed on the tissue samples to verify the protein expression of FAT1 in pancreatic adenocarcinoma and its relationship with immune-related proteins, the degree of differentiation of pancreatic adenocarcinoma, clinical staging, and prognosis. (1) Bioinformatics analysis: the FAT1 mRNA expression of 179 pancreatic adenocarcinoma tissues from the TCGA database was 5.55±1.04, which was higher than that of 328 normal pancreatic tissues with FAT1 mRNA from the GTEx database (2.95±0.53, ＜0.001). FAT1-specific IHC images showed that FAT1 expression was generally high in pancreatic adenocarcinoma tissues, and FAT1 expression shifted from the cell membrane to the cytoplasm. The FAT1 mRNA expression in the highly differentiated group (31 cases), the moderately differentiated group (96 cases), and the lowly differentiated group (52 cases) were 4.99±1.46, 5.51±0.80, and 5.68±1.08, the expression of pancreatic adenocarcinoma tissues were all higher than that of normal pancreatic tissues (all ＜0.001), and the FAT1 mRNA expression of the moderately differentiated group and the poorly differentiated group were all higher than that of the highly differentiated group (all ＜0.001). The median progression-free survival time (PFS) and median overall survival time (OS) of the 90 patients in the FAT1 mRNA low-expression group were 16.5 and 24 months, respectively, which were longer than those of the 89 patients in the FAT1 mRNA high-expression group (median PFS and OS were 13 and 18 months, respectively; -values were 0.011 and 0.005, respectively). Multifactorial Cox regression analysis showed that FAT1 mRNA expression level was an independent influencing factor for OS in pancreatic adenocarcinoma patients (=1.47, 95% : 1.09-1.99). Correlation analysis showed that FAT1 mRNA expression in pancreatic adenocarcinoma was positively correlated with B-cell infiltration, CD8+ T-cell infiltration, neutrophil infiltration, macrophage infiltration, and myeloid dendritic cell infiltration (=0.27, ＜0.001; =0.28, ＜0.001; =0.32, ＜0.001; =0.21, =0.004; =0.32, ＜0.001), and also positively correlated with mRNA expression of CD274, HAVCR2, and PDCD1LG2 (=0.327, ＜0.001; =0.231, =0.002; =0.258, ＜0.001). GO and KEGG enrichment analyses showed that FAT1 mRNA expression levels were associated with activation of the Wnt signaling pathway (=0.029), the PI3K/Akt pathway (<0.001), and other tumor microenvironment-related pathways. (2) Validation of own tissue samples: among 192 pancreatic adenocarcinoma tissues, FAT1 was highly expressed in 58 cases (30.21%), and the proportion of FAT1-expressing positive tumor cells was positively correlated with the combined positive score of PD-L1 and the number of CD3+ T-cells infiltration (=0.154, =0.032; =0.287, ＜0.001), and the protein expression of FAT1 had no correlation with the differentiation degree of pancreatic adenocarcinoma (=0.082, =0.254). The median OS of 58 patients in the FAT1 high-expression group and 134 patients in the FAT1 low-expression group were 18.89 and 25.84 months, respectively, and the difference was not statistically significant (χ²=1.93, =0.165). FAT1 gene is highly expressed in pancreatic adenocarcinoma tissues, may play an oncogenic role in pancreatic adenocarcinoma, may be an adverse influence on overall survival and progression-free survival of patients; FAT1 gene may be involved in multiple immune-related pathways and promote tumor immune escape.
分析FAT1基因在胰腺腺癌中的表达及其与胰腺腺癌临床病理特征、预后和免疫治疗的关系。(1)生物信息学分析：基于TCGA数据库中179例胰腺腺癌的FAT1 mRNA表达和临床数据，以及GTEx数据库中328例正常胰腺组织的FAT1 mRNA表达数据。我们分析了胰腺腺癌与正常胰腺组织中FAT1 mRNA表达的差异，以及FAT1 mRNA表达与胰腺腺癌分化程度、临床分期、预后、免疫细胞浸润和免疫检查点相关基因的关系。应用Limma 3.40.2软件包分析FAT1相关差异表达基因，并对差异表达基因进行GO和KEGG富集分析。通过HPA数据库分析胰腺腺癌和正常胰腺组织中FAT1的免疫组织化学(IHC)。(2)自身组织样本验证：收集2010年3月8日至2020年9月30日在浙江省肿瘤医院收治的192例胰腺导管腺癌患者的组织样本及临床和预后数据。对组织样本进行IHC，以验证FAT1在胰腺腺癌中的蛋白表达及其与免疫相关蛋白、胰腺腺癌分化程度、临床分期和预后的关系。(1)生物信息学分析：来自TCGA数据库的179例胰腺腺癌组织的FAT1 mRNA表达为5.55±1.04，高于来自GTEx数据库的328例具有FAT1 mRNA的正常胰腺组织(2.95±0.53，＜0.001)。FAT1特异性IHC图像显示，FAT1在胰腺腺癌组织中表达普遍较高，且FAT1表达从细胞膜转移至细胞质。高分化组(31例)、中分化组(96例)和低分化组(52例)胰腺腺癌组织的FAT1 mRNA表达分别为4.99±1.46、5.51±0.80和5.68±1.08，均高于正常胰腺组织(均＜0.001)，且中分化组和低分化组的FAT1 mRNA表达均高于高分化组(均＜0.001)。FAT1 mRNA低表达组的90例患者的中位无进展生存期(PFS)和中位总生存期(OS)分别为16.5个月和24个月，长于FAT1 mRNA高表达组的89例患者(中位PFS和OS分别为13个月和18个月；P值分别为0.011和0.005)。多因素Cox回归分析显示，FAT1 mRNA表达水平是胰腺腺癌患者OS的独立影响因素(HR = 1.47，95%CI：1.09 - 1.99)。相关性分析显示，胰腺腺癌中FAT1 mRNA表达与B细胞浸润、CD8 + T细胞浸润、中性粒细胞浸润、巨噬细胞浸润和髓样树突状细胞浸润呈正相关(r = 0.27，＜0.001；r = 0.28，＜0.001；r = 0.32，＜0.001；r = 0.21，P = 0.004；r = 0.32，＜0.001)，也与CD274、HAVCR2和PDCD1LG2的mRNA表达呈正相关(r = 0.327，＜0.001；r = 0.231，P = 0.002；r = 0.258，＜0.001)。GO和KEGG富集分析显示，FAT1 mRNA表达水平与Wnt信号通路激活(校正P = 0.029)、PI3K/Akt通路(校正P＜0.001)及其他肿瘤微环境相关通路有关。(2)自身组织样本验证：192例胰腺腺癌组织中，58例(30.21%)FAT1高表达，FAT1表达阳性肿瘤细胞比例与PD - L1联合阳性评分及CD3 + T细胞浸润数量呈正相关(r = 0.154，P = 0.032；r = 0.287，＜0.001)，FAT1蛋白表达与胰腺腺癌分化程度无相关性(r = 0.082，P = 0.254)。FAT1高表达组的58例患者和FAT1低表达组的134例患者的中位OS分别为18.89个月和25.84个月，差异无统计学意义(χ² = 1.93，P = 0.165)。FAT1基因在胰腺腺癌组织中高表达，可能在胰腺腺癌中发挥致癌作用，可能对患者的总生存期和无进展生存期产生不利影响；FAT1基因可能参与多个免疫相关通路并促进肿瘤免疫逃逸。
