Bai Lanxiang, Peng Xiaonu, Sun Ruimei
Disinfection Supply Center, Yantai Yuhuangding Hospital, Yantai 264000, Shandong, People's Republic of China.
Department of Thoracic Surgery, Yantai Yuhuangding Hospital, Yantai 264000, Shandong, People's Republic of China.
Cancer Manag Res. 2020 Sep 25;12:9125-9137. doi: 10.2147/CMAR.S258370. eCollection 2020.
Protein kinase Cα (PRKCA) is an oncogene in multiple cancers including non-small-cell lung cancer (NSCLC) and can be transcribed into a number of circular PRKCAs (circPRKCAs). Here, we aimed to elaborate the role and mechanism of circPRKCA_024 (circPRKCA) in malignant progression of NSCLC.
Expression of circPRKCA, miRNA (miR)-330-5p and 3-phosphoinositide-dependent protein kinase-1 (PDK1) was measured by real-time quantitative PCR and Western blotting, and their relationship was testified by dual-luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay. Cell behaviors were evaluated by cell counting kit (CCK)-8, flow cytometry, and transwell assays. AKT activity was confirmed by Western blotting. Xenograft experiment assessed tumor growth.
Expression of circPRKCA and PDK1 was upregulated, and miR-330-5p was downregulated in NSCLC tissues and cell lines. High circPRKCA was correlated with TNM stage and lymph node metastasis of NSCLC patients. Silencing circPRKCA could suppress cell viability, migration, and invasion in A549 and H1299 cells, accompanied with apoptosis rate promotion. Moreover, circPRKCA knockdown retarded tumor growth of A549 cells in vivo. Molecularly, miR-330-5p was sponged by circPRKCA, and PDK1 was a target of miR-330-5p. Inhibiting miR-330-5p could attenuate the suppression of circPRKCA knockdown on cell growth, migration, and invasion; contrarily, promoting miR-330-5p caused inhibition on those cell behaviors by downregulating PDK1. Analogously, AKT activity was suppressed by circPRKCA downregulation and miR-330-5p upregulation in NSCLC cells both in vitro and in vivo.
Depleting circPRKCA inhibited PDK1 to suppress NSCLC cell malignant behaviors through miR-330-5p/PDK1/AKT pathway.
蛋白激酶Cα（PRKCA）在包括非小细胞肺癌（NSCLC）在内的多种癌症中是一种癌基因，并且可以转录成多种环状PRKCA（circPRKCA）。在此，我们旨在阐述circPRKCA_024（circPRKCA）在NSCLC恶性进展中的作用及机制。
通过实时定量PCR和蛋白质印迹法检测circPRKCA、微小RNA（miR）-330-5p和3-磷酸肌醇依赖性蛋白激酶-1（PDK1）的表达，并通过双荧光素酶报告基因检测、RNA免疫沉淀和RNA下拉检测来验证它们之间的关系。通过细胞计数试剂盒（CCK）-8、流式细胞术和Transwell检测评估细胞行为。通过蛋白质印迹法确认AKT活性。异种移植实验评估肿瘤生长情况。
在NSCLC组织和细胞系中，circPRKCA和PDK1的表达上调，而miR-330-5p的表达下调。高circPRKCA与NSCLC患者的TNM分期和淋巴结转移相关。沉默circPRKCA可抑制A549和H1299细胞的活力、迁移和侵袭，并促进细胞凋亡率。此外，circPRKCA敲低可抑制A549细胞在体内的肿瘤生长。在分子水平上，circPRKCA可吸附miR-330-5p，且PDK1是miR-330-5p的靶标。抑制miR-330-5p可减弱circPRKCA敲低对细胞生长、迁移和侵袭的抑制作用；相反，促进miR-330-5p可通过下调PDK1对这些细胞行为产生抑制作用。类似地，在体外和体内，NSCLC细胞中circPRKCA下调和miR-330-5p上调均可抑制AKT活性。
消耗circPRKCA可通过miR-330-5p/PDK1/AKT途径抑制PDK1，从而抑制NSCLC细胞的恶性行为。
