School of Basic Medicine, Hainan Medical University, Haikou, 571199, China.
State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, 100850, China.
J Cancer Res Clin Oncol. 2023 Dec;149(19):17495-17509. doi: 10.1007/s00432-023-05473-9. Epub 2023 Oct 30.
Mitogen-activated protein kinases (MAPK), specifically the c-Jun N-terminal kinase (JNK)-MAPK subfamily, play a crucial role in the development of various cancers, including hepatocellular carcinoma (HCC). However, the specific roles of JNK1/2 and their upstream regulators, MKK4/7, in HCC carcinogenesis remain unclear.
In this study, we performed differential expression analysis of JNK-MAPK components at both the transcriptome and protein levels using TCGA and HPA databases. We utilized Kaplan-Meier survival plots and receiver operating characteristic (ROC) curve analysis to evaluate the prognostic performance of a risk scoring model based on these components in the TCGA-HCC cohort. Additionally, we conducted immunoblotting, apoptosis analysis with FACS and soft agar assays to investigate the response of JNK-MAPK pathway components to various death stimuli (TRAIL, TNF-α, anisomycin, and etoposide) in HCC cell lines.
JNK1/2 and MKK7 levels were significantly upregulated in HCC samples compared to paracarcinoma tissues, whereas MKK4 was downregulated. ROC analyses suggested that JNK2 and MKK7 may serve as suitable diagnostic genes for HCC, and high JNK2 expression correlated with significantly poorer overall survival. Knockdown of JNK1 enhanced TRAIL-induced apoptosis in hepatoma cells, while JNK2 knockdown reduced TNF-α/cycloheximide (CHX)-and anisomycin-induced apoptosis. Neither JNK1 nor JNK2 knockdown affected etoposide-induced apoptosis. Furthermore, MKK7 knockdown augmented TNF-α/CHX- and TRAIL-induced apoptosis and inhibited colony formation in hepatoma cells.
Targeting MKK7, rather than JNK1/2 or MKK4, may be a promising therapeutic strategy to inhibit the JNK-MAPK pathway in HCC therapy.
丝裂原活化蛋白激酶（MAPK），特别是 c-Jun N 末端激酶（JNK）-MAPK 亚家族，在多种癌症的发展中发挥着关键作用，包括肝细胞癌（HCC）。然而，JNK1/2 及其上游调节物 MKK4/7 在 HCC 癌变中的具体作用尚不清楚。
本研究利用 TCGA 和 HPA 数据库，在转录组和蛋白质水平上对 JNK-MAPK 成分进行差异表达分析。我们利用 Kaplan-Meier 生存图和受试者工作特征（ROC）曲线分析，评估基于这些成分的风险评分模型在 TCGA-HCC 队列中的预后性能。此外，我们还进行了免疫印迹、FACS 分析和软琼脂实验，以研究 JNK-MAPK 通路成分对 HCC 细胞系中各种死亡刺激（TRAIL、TNF-α、anisomycin 和 etoposide）的反应。
与癌旁组织相比，HCC 样本中 JNK1/2 和 MKK7 水平显著上调，而 MKK4 下调。ROC 分析表明，JNK2 和 MKK7 可能是 HCC 的合适诊断基因，JNK2 高表达与总生存期显著缩短相关。JNK1 敲低增强了 TRAIL 诱导的肝癌细胞凋亡，而 JNK2 敲低减少了 TNF-α/环已酰亚胺（CHX）-和 anisomycin 诱导的凋亡。JNK1 或 JNK2 敲低均不影响 etoposide 诱导的凋亡。此外，MKK7 敲低增强了 TNF-α/CHX-和 TRAIL 诱导的凋亡，并抑制了肝癌细胞的集落形成。
靶向 MKK7，而不是 JNK1/2 或 MKK4，可能是抑制 HCC 治疗中 JNK-MAPK 通路的一种有前途的治疗策略。
