PO.MCB08.01 · 分子与细胞生物学
干扰素富集的基因表达特征与口腔鳞状细胞癌中的 ADAR1 依赖性相关
Interferon enriched gene expression signatures are associated with ADAR1 dependency in oral squamous cell carcinoma
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
口腔鳞状细胞癌（OSCC）在东南亚地区高发，由于有效治疗手段有限，其 5 年生存率仍然较低，凸显了对新型治疗策略的需求。我们近期的工作表明，作用于 RNA 的腺苷脱氨酶 1（ADAR1），尤其是 p150 异构体，对 OSCC 细胞存活至关重要，使其成为一个有前景的治疗靶点。然而，由于这种依赖性的基础尚未被完全理解，判断哪些患者可能对 ADAR1 抑制产生应答仍具挑战性。本研究旨在（1）预测 OSCC 肿瘤中的 ADAR1 依赖性，以及（2）界定与 ADAR1 缺失相关的基因表达变化。针对目标 1，我们使用 RNA 测序数据对具有已验证 ADAR1 依赖性状态的 OSCC 细胞系进行了差异基因表达（DEG）分析。根据这些 DEG 的平均 z 分数生成 ADAR1 依赖性特征评分，并应用于癌症基因组图谱（TCGA）中的 313 例 OSCC 肿瘤。针对目标 2，我们在多个 OSCC 细胞系中使用 siRNA 选择性地敲低 p150 异构体，随后进行 RNA 测序。采用基因集富集分析（GSEA）鉴定在依赖性和低依赖性细胞系中因 ADAR1-p150 敲低而改变的通路。我们发现约 93% 的 OSCC 肿瘤被预测为 ADAR1 依赖性，这与我们此前的 CRISPR 筛选结果一致。GSEA 揭示在 ADAR1 依赖性肿瘤中富集了干扰素（IFN）-α/β 信号和角化通路。ADAR1-p150 依赖性细胞系表现出众多干扰素刺激基因（ISG）的更高基础表达水平。在 ADAR1-p150 敲低后，这些细胞系表现出显著的细胞致死性，并伴随 IFN 相关通路的富集，而低依赖性细胞系则既未表现出生长抑制，也未出现 IFN 信号的显著上调。定量 PCR 和蛋白分析证实，在 ADAR1-p150 敲低后，依赖性 OSCC 细胞系中 IFN-β 及包括 CXCL10 和 ISG15 在内的若干 ISG 出现上调。总之，这些发现表明 ADAR1 依赖性特征可对 OSCC 肿瘤进行分层，并识别出可能从 ADAR1 靶向疗法中获益的患者。ISG 表达富集的 OSCC 对 ADAR1-p150 缺失更为敏感，由此产生的 IFN 相关基因特征上调可能作为治疗应答的生物标志物。
查看英文原文 English abstract
Oral squamous cell carcinoma (OSCC) is prevalent in Southeast Asia, and the 5-year survival rate remains poor due to limited effective treatments, underscoring the need for new therapeutic strategies. Our recent work shows that adenosine deaminase acting on RNA 1 ( ADAR1 ), particularly the p150 isoform, is essential for OSCC cell survival, making it a promising therapeutic target. However, determining which patients may respond from ADAR1 inhibition remains challenging because the basis of this dependency is not fully understood. This study aimed (1) to predict ADAR1 dependency in OSCC tumors and (2) to define the gene expression changes associated with ADAR1 loss. For Aim 1, differential gene expression (DEG) analysis was performed on OSCC cell lines with validated ADAR1 dependency status using RNA-sequencing data. ADAR1-dependency signature scores were generated from the average z-scores of these DEGs and applied to 313 OSCC tumors in The Cancer Genome Atlas (TCGA). For Aim 2, we selectively knocked down the p150 isoform using siRNA in multiple OSCC cell lines followed by RNA-sequencing. Gene Set Enrichment Analysis (GSEA) was used to identify pathways altered by ADAR1-p150 knockdown in both dependent and less-dependent lines. We found that ~93% of OSCC tumors were predicted to be ADAR1-dependent, consistent with our previous CRISPR screen findings. GSEA revealed enrichment of interferon (IFN)-alpha/beta signaling and keratinization pathways in ADAR1-dependent tumors. ADAR1-p150-dependent cell lines exhibited higher basal expression of numerous interferon-stimulated genes (ISGs). Upon ADAR1-p150 knockdown, these lines showed significant cell lethality accompanied by enrichment of IFN-related pathways, whereas less-dependent lines showed neither growth inhibition nor substantial upregulation in IFN signaling. Quantitative PCR and protein analyses confirmed upregulation of IFN-beta and several ISGs including CXCL10 and ISG15 in dependent OSCC line upon ADAR1-p150 knockdown. Together, these findings show that ADAR1 dependency signatures can stratify OSCC tumors and identify patients likely to benefit from ADAR1-targeted therapies. OSCCs with enriched ISG expression are more susceptible to ADAR1-p150 loss, and the resulting upregulation of IFN-related gene signatures may serve as a biomarker of therapeutic response.
利益披露 Disclosure
P. Yee, None..
J. Teo, None..
S. Yee, None..
S. Ooi, None..
Y. Tan, None..
M. Garnett, None..
S. Ng, None..
A. Chai, None..
S. Cheong, None.