Chen Gang, Li Zhexuan, Chen Changhan, Liu Jiajia, Zhu Weiming, She Li, Huang Huimei, Qin Yuexiang, Liu Guancheng, Wang Juncheng, Liu Yong, Huang Donghai, Tang Qinglai, Zhang Xin, Zhu Gangcai
Department of Otolaryngology-Head and Neck Surgery, The Xiangya Hospital, Central South University, Changsha, China.
Department of Otolaryngology-Head and Neck Surgery, The Second Xiangya Hospital, Central South University, Changsha, China.
Front Oncol. 2021 Jan 8;10:565669. doi: 10.3389/fonc.2020.565669. eCollection 2020.
PRAS40 (Prolin-rich Akt substrate of 40 kDa) is a critical protein, which directly connects PI3K/Akt and mTORC1 pathway. It plays an indispensable role in the development of various diseases. However, the relationship between PRAS40 and head and neck squamous cell carcinoma (HNSCC) remains unclear. Here, our study indicated that high expression of PRAS40 mRNA is a favorable prognostic factor in HNSCC patients by analyzing 498 clinical and mRNA data. Moreover, we confirmed that CRISPR/Cas9 induced PRAS40-knockout would promote colony formation, cell migration, and invasion in several HNSCC cell lines. RNA-seq was employed to investigate the further possible mechanisms involving the above regulations by PRAS40 in HNSCC cells. The molecular landscape contributed by 253 differentially expressed mRNA after PRAS40-knockout was enriched in TGF-beta, PI3K-Akt, P53, mTOR, NF-B signaling pathway. Partial molecular alternations within these pathways were validated by qPCR or Western blotting. Besides, we found that high expression of PRAS40 in HNSC patients would present more CD8 T and T follicular helper cells, but less Th17 cells than the patients with low expression of PRAS40. The altered molecular pathways and tumor-infiltrating immune cells might associate with the mechanism of PRAS40 being a suppressor in HNSCC cells, which would provide a potential prognostic predictor and therapeutic target in HNSCC patients.
富含脯氨酸的40kDa Akt底物（PRAS40）是一种关键蛋白，它直接连接PI3K/Akt和mTORC1信号通路。它在多种疾病的发展中起着不可或缺的作用。然而，PRAS40与头颈部鳞状细胞癌（HNSCC）之间的关系仍不清楚。在此，我们的研究通过分析498例临床和mRNA数据表明，PRAS40 mRNA的高表达是HNSCC患者的一个有利预后因素。此外，我们证实CRISPR/Cas9诱导的PRAS40基因敲除会促进几种HNSCC细胞系的集落形成、细胞迁移和侵袭。采用RNA测序来研究PRAS40在HNSCC细胞中上述调控作用的进一步可能机制。PRAS40基因敲除后253个差异表达mRNA所呈现的分子图谱在TGF-β、PI3K-Akt、P53、mTOR、NF-κB信号通路中富集。这些信号通路中的部分分子变化通过qPCR或蛋白质印迹法得到验证。此外，我们发现HNSC患者中PRAS40的高表达相较于PRAS40低表达的患者会呈现更多的CD8 T细胞和滤泡辅助性T细胞，但Th17细胞较少。分子通路的改变和肿瘤浸润免疫细胞可能与PRAS40作为HNSCC细胞抑制因子的机制相关，这将为HNSCC患者提供一个潜在的预后预测指标和治疗靶点。
