Abstract
Objective:To investigate role of miR-4738-3p in targeting tryptophan 2,3-dioxygenase 2(TDO2)to regulate energy metabolism and inhibit immune escape in thyroid cancer cells.Methods:A total of 68 cases of thyroid cancer tissues and their corresponding adjacent non-cancerous tissues were collected,expressions of miR-4738-3p and TDO2 in tissues and cell lines were de-tected by qRT-PCR,relationship between miR-4738-3p expression and clinicopathological characteristics was analyzed.Effects of miR-4738-3p and TDO2 on proliferation,migration,invasion,energy metabolism and immune escape of TPC-1 and BCPAP cells were examined through CCK-8,clone formation,wound healing,Transwell experiments,biochemical analyses,ELISA and NK cell co-culture experiments,targeting relationship between miR-4738-3p and TDO2 was validated by dual luciferase reporter gene assay.In vivo xenograft experiments and immunohistochemical detections were conducted to observe effects of miR-4738-3p on tumorigenesis and expression of immune escape-related proteins in TPC-1 and BCPAP cells.Results:miR-4738-3p was lowly expressed(P<0.05),while TDO2 was highly expressed in thyroid cancer(P<0.05).Tumor size,lymph node metastasis and TNM staging were correlated with expression of miR-4738-3p(P<0.05).Compared with miR-NC group,miR-4738-3p mimics group exhibited decreased prolifera-tion,clone formation,migration,invasion ability,glucose uptake,lactate production,ATP/ADP ratio,TDO2 mRNA and protein expressions,tumor volume,mass,Ki-67,TDO2 and PD-L1 expressions(P<0.05),NAD+/NADH ratio,IFN-γ,TNF-α levels and NK cell killing rate were increased(P<0.05).miR-4738-3p inhibitor group showed increased proliferation,clone formation,migration,invasion ability,glucose uptake,lactate production,ATP/ADP ratio,TDO2 mRNA and protein expressions(P<0.05),NAD+/NADH ratio,IFN-γ,TNF-α levels and NK cell killing rate were decreased(P<0.05).Binding sites were identified between miR-4738-3p and TDO2,and their expression were negatively correlated(r=-0.485 3,P<0.001).Compared with sh-NC group,proliferation,clone formation,migration,invasion ability,glucose uptake,lactate production and ATP/ADP ratio were decreased in sh-TDO2 group(P<0.05),NAD+/NADH ratio,IFN-γ,TNF-α levels and NK cell killing rate were increased(P<0.05).Compared with Scrambled group,proliferation,clone formation,migration,invasion ability,glucose uptake,lactate production and ATP/ADP ratio were increased in TDO2 group(P<0.05),NAD+/NADH ratio,IFN-γ,TNF-α levels and NK cell killing rate were decreased(P<0.05).Conclusion:miR-4738-3p targets TDO2 to regulate energy metabolism,inhibiting thyroid cancer cell proliferation,metastasis and immune escape.关键词
miR-4738-3p/色氨酸2,3-加双氧酶2/甲状腺癌/能量代谢/免疫逃逸Key words
miR-4738-3p/Tryptophan 2,3-dioxygenase 2/Thyroid cancer/Energy metabolism/Immune escape分类
临床医学
