Chen Yun, Hong Chaojin, Zhou Qihao, Qin Zhiquan
Cancer Center, Department of Medical Oncology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, China.
Front Oncol. 2022 Jun 9;12:804287. doi: 10.3389/fonc.2022.804287. eCollection 2022.
The majority of drug-resistant cells in Thyroid cancer (THCA) tend to exhibit an Epithelial mesenchymal transition (EMT) phenotype, and abnormal expression of the cell adhesion molecule Cadherin2 (CDH2) is a hallmark of EMT. However, the roles of CDH2 in THCA and its underlying mechanisms are unknown.
We analyzed the CDH2 expression in The Cancer Genome Atlas (TCGA) database and screened for genes positively associated with CDH2. Small interfering RNA and cell transfection were used for knocking down CDH2 in THCA cells, cell counting kit-8 (CCK-8) assay and immunofluorescence to detect cell proliferation. Binding miRNAs of CDH2 and CDH2-associated genes were predicted using the Encyclopedia of RNA Interactomes (ENCORI) database. The expression of genes in clinical THCA tissues was investigated from the Human Protein Atlas (HPA) database and validated by qRT-PCR. We conducted the cell functions pathways of CDH2 and CDH2-associated gene FRMD3 by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. We also showed the correlation between CDH2 and FRMD3 expression and tumor immune infiltration.
The expression of CDH2 was significantly higher in THCA tumor tissues compared to normal tissues. Moreover, there were strongly associations of CDH2 expression with the stages T and N. Cellular function assays showed that CDH2 exerted its growth-promoting activity of THCA. To better understand how CDH2 was regulated in THCA, we sought genes associated with CDH2. Correlation analysis revealed that there were negative correlations between genes (CDH2, FRMD3) and miRNAs (hsa-miR-410-3p, hsa-miR-411-5p, hsa-miR-299-5p). Moreover, CDH2 and FRMD3 expression were significantly higher in tumor tissues than in normal tissues, while hsa-miR-410-3p, hsa-miR-411-5p and hsa-miR-299-5p were significantly decreased in tumor tissues compared with normal tissues in THCA. GO and KEEG results showed that CDH2 and FRMD3 were strongly associated with immune-related functions. High expression of CDH2 and FRMD3 was linked to the suppression of immune cells. There were strong negativity correlations between CDH2, FRMD3 and T-cell exhaustion factors.
Our data indicated that CDH2 and CDH2-related gene FRMD3 might have the critical effects on altering tumors becoming 'cold tumors' eventually leading to immune checkpoint inhibitor resistance.
甲状腺癌（THCA）中的大多数耐药细胞倾向于表现出上皮-间质转化（EMT）表型，细胞粘附分子钙黏蛋白2（CDH2）的异常表达是EMT的一个标志。然而，CDH2在THCA中的作用及其潜在机制尚不清楚。
我们分析了癌症基因组图谱（TCGA）数据库中CDH2的表达，并筛选出与CDH2呈正相关的基因。使用小干扰RNA和细胞转染技术敲低THCA细胞中的CDH2，采用细胞计数试剂盒-8（CCK-8）法和免疫荧光法检测细胞增殖。利用RNA相互作用组百科全书（ENCORI）数据库预测CDH2的结合微小RNA（miRNA）和与CDH2相关的基因。从人类蛋白质图谱（HPA）数据库研究临床THCA组织中基因的表达，并通过qRT-PCR进行验证。我们通过基因本体论（GO）和京都基因与基因组百科全书（KEGG）分析对CDH2和与CDH2相关的基因FRMD3进行细胞功能通路分析。我们还展示了CDH2和FRMD3表达与肿瘤免疫浸润之间的相关性。
与正常组织相比，THCA肿瘤组织中CDH2的表达显著更高。此外，CDH2表达与T分期和N分期密切相关。细胞功能实验表明，CDH2发挥了其促进THCA生长的活性。为了更好地了解THCA中CDH2是如何被调控的，我们寻找与CDH2相关的基因。相关性分析显示，基因（CDH2、FRMD3）与miRNA（hsa-miR-410-3p、hsa-miR-411-5p、hsa-miR-299-5p）之间存在负相关。此外，肿瘤组织中CDH2和FRMD3的表达明显高于正常组织，而在THCA中，与正常组织相比，肿瘤组织中hsa-miR-410-3p、hsa-miR-411-5p和hsa-miR-299-5p明显降低。GO和KEGG结果表明，CDH2和FRMD3与免疫相关功能密切相关。CDH2和FRMD3的高表达与免疫细胞的抑制有关。CDH2、FRMD3与T细胞耗竭因子之间存在强烈的负相关。
我们的数据表明，CDH2和与CDH2相关的基因FRMD3可能对改变肿瘤最终成为“冷肿瘤”并导致免疫检查点抑制剂耐药具有关键作用。
