Targeting the IDO-BCL2A1-Cytochrome c Pathway Promotes Apoptosis in Oral Squamous Cell Carcinoma.
Targeting the IDO-BCL2A1-Cytochrome c Pathway Promotes Apoptosis in Oral Squamous Cell Carcinoma.
复制标题
靶向 IDO-BCL2A1-细胞色素 c 通路促进口腔鳞状细胞癌细胞凋亡
DOI：
10.2147/ott.s288692
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发表时间：
2021
影响因子：
4
通讯作者：
Chen F
中科院分区：
文献类型：
--
作者：
Zheng Q;Gan G;Gao X;Luo Q;Chen F
目的吲哚胺2，3-双加氧酶（Indolamine 2，3-dioxygenase，IDO）是色氨酸降解的限速酶，是口腔鳞状细胞癌（oral squamous cell carcinoma，OSCC）患者预后不良的因素，但其分子机制尚不清楚。本研究旨在探讨IDO在口腔鳞癌中的表达及其生物学功能。材料与方法采用qPCR、Western印迹和免疫组化（IHC）分析IDO在口腔鳞癌细胞系和组织标本中的表达。采用超高效液相色谱-串联质谱法测定口腔鳞癌患者和健康对照者血清中色氨酸和犬尿氨酸的含量。使用Oncomine数据库和Kaplan-Meier生存分析来确定IDO表达及其与OSCC预后的相关性。采用细胞计数、CCK 8测定、流式细胞术、细胞周期和EdU掺入测定来评估通过shRNA或IDO特异性抑制剂（epacadostat）体外抑制IDO对OSCC生长的影响。建立OSCC异种移植小鼠模型以验证IDO抑制的预测体内功能。在机制上，84基因凋亡PCR阵列和拯救实验被用来表征IDO调节OSCC细胞凋亡的潜在机制。结果IDO在OSCC细胞系和组织中表达上调，并与OSCC的进展呈负相关。慢病毒介导的IDO敲低和epacadostat在体外和体内显著降低了OSCC细胞的活力并促进了细胞凋亡。凋亡基因芯片检测结果显示BCL 2相关蛋白A1（BCL 2A 1）在转录水平上变化最明显。IDO抑制剂下调BCL 2A 1表达，增加细胞色素c的表达和转位，从而促进细胞凋亡。BCL 2A 1的过表达逆转了IDO抑制的促凋亡作用。结论IDO通过调节BCL 2A 1的表达直接影响OSCC细胞的生长。IDO和IDO-BCL 2A 1-细胞色素c轴可能是OSCC潜在的治疗靶点。
Purpose Indolamine 2,3-dioxygenase (IDO) is the rate limiting enzyme of tryptophan degradation and is a negative prognostic factor in oral squamous cell carcinoma (OSCC) patients, while the underlying molecular mechanism remains unclear. This research aimed to explore the IDO expression and its biological functions in OSCC. Materials and Methods IDO expression was analyzed by qPCR, Western blots, and immunohistochemistry (IHC) in OSCC cell lines and tissue specimens. Tryptophan and kynurenine content were determined by UPLC-MS/MS in serum samples of OSCC patients and healthy controls. Oncomine databases and Kaplan-Meier survival analyses were used to identify the IDO expression and its correlation with OSCC prognosis. Cell counting, CCK8 assay, flow cytometry, cell cycle, and EdU incorporation assays were used to assess the effect of IDO inhibition on OSCC growth either by shRNA or the IDO-specific inhibitor (epacadostat) in vitro. An OSCC xenograft mouse model was established to verify the predicted function of IDO inhibition in vivo. Mechanistically, an 84-gene apoptosis PCR array and rescue experiment were used to characterize the underlying mechanism involved in IDO-regulated apoptosis in OSCC. Results IDO expression was upregulated in OSCC cell lines and tissues and was negatively correlated with OSCC progression. Lentivirus-mediated IDO knockdown and epacadostat significantly reduced viability and promoted apoptosis of OSCC cells in vitro and in vivo. The apoptosis PCR array identified BCL2 related protein A1 (BCL2A1) as the most obviously changed gene at the transcriptional level. IDO inhibition downregulated BCL2A1 expression, increased the expression and translocation of cytochrome c, thus promoted apoptosis in OSCC. Overexpression of BCL2A1 reversed the pro-apoptotic effect of IDO inhibition. Conclusion The present results revealed that IDO directly affect the growth of OSCC cells by regulating BCL2A1 expression. IDO and the IDO-BCL2A1-cytochrome c axis may be potential therapeutic targets for OSCC.