A novel peptide PDHK1-241aa encoded by circPDHK1 promotes ccRCC progression via interacting with PPP1CA to inhibit AKT dephosphorylation and activate the AKT-mTOR signaling pathway

作者全名："Huang, Bo; Ren, Junwu; Ma, Qiang; Yang, Feifei; Pan, Xiaojuan; Zhang, Yuying; Liu, Yuying; Wang, Cong; Zhang, Dawei; Wei, Ling; Ran, Lingyu; Zhao, Hongwen; Liang, Ce; Wang, Xiaolin; Wang, Shiming; Li, Haiping; Ning, Hao; Ran, Ai; Li, Wei; Wang, Yongquan; Xiao, Bin"

作者地址："[Huang, Bo; Ren, Junwu; Ma, Qiang; Yang, Feifei; Pan, Xiaojuan; Zhang, Yuying; Liu, Yuying; Liang, Ce; Wang, Xiaolin; Wang, Shiming; Li, Haiping; Ning, Hao; Ran, Ai; Xiao, Bin] Chongqing Med Univ, Coll Pharm, Chongqing 400016, Peoples R China; [Huang, Bo] Zunyi Med Univ, Key Lab Basic Pharmacol, Minist Educ, Zunyi 563006, Guizhou, Peoples R China; [Huang, Bo] Zunyi Med Univ, Joint Int Res Lab Ethnomed, Minist Educ, Zunyi 563006, Guizhou, Peoples R China; [Wang, Cong; Zhang, Dawei; Wei, Ling; Wang, Yongquan] Army Med Univ, Southwest Hosp, Dept Urol, Chongqing 400038, Peoples R China; [Ran, Lingyu; Zhao, Hongwen] Army Med Univ, Southwest Hosp, Dept Kidney, Chongqing 400038, Peoples R China; [Li, Wei] Chongqing Univ Canc Hosp, Dept Pharm, Chongqing 400030, Peoples R China"

通信作者："Xiao, B (通讯作者)，Chongqing Med Univ, Coll Pharm, Chongqing 400016, Peoples R China.; Wang, YQ (通讯作者)，Army Med Univ, Southwest Hosp, Dept Urol, Chongqing 400038, Peoples R China.; Li, W (通讯作者)，Chongqing Univ Canc Hosp, Dept Pharm, Chongqing 400030, Peoples R China."

来源：MOLECULAR CANCER

ESI学科分类：MOLECULAR BIOLOGY & GENETICS

WOS号：WOS:001163067900001

JCR分区：Q1

影响因子：27.7

年份：2024

卷号：23

期号：1

开始页：　

结束页：　

文献类型：Article

关键词：Clear cell renal cell carcinoma; CircPDHK1; Novel peptide; PPP1CA; Dephosphorylation

摘要："BackgroundClear cell renal cell carcinoma (ccRCC) is the most prevalent kidney cancer with high aggressive phenotype and poor prognosis. Accumulating evidence suggests that circRNAs have been identified as pivotal mediators in cancers. However, the role of circRNAs in ccRCC progression remains elusive.MethodsThe differentially expressed circRNAs in 4 paired human ccRCC and adjacent noncancerous tissues ccRCC were screened using circRNA microarrays and the candidate target was selected based on circRNA expression level using weighted gene correlation network analysis (WGCNA) and the gene expression omnibus (GEO) database. CircPDHK1 expression in ccRCC and adjacent noncancerous tissues (n = 148) were evaluated along with clinically relevant information. RT-qPCR, RNase R digestion, and actinomycin D (ActD) stability test were conducted to identify the characteristics of circPDHK1. The subcellular distribution of circPDHK1 was analyzed by subcellular fractionation assay and fluorescence in situ hybridization (FISH). Immunoprecipitation-mass spectrometry (IP-MS) and immunofluorescence (IF) were employed to evaluate the protein-coding ability of circPDHK1. ccRCC cells were transfected with siRNAs, plasmids or lentivirus approach, and cell proliferation, migration and invasion, as well as tumorigenesis and metastasis in nude mice were assessed to clarify the functional roles of circPDHK1 and its encoded peptide PDHK1-241aa. RNA-sequencing, western blot analysis, immunoprecipitation (IP) and chromatin immunoprecipitation (ChIP) assays were further employed to identify the underlying mechanisms regulated by PDHK1-241aa.ResultsCircPDHK1 was upregulated in ccRCC tissues and closely related to WHO/ISUP stage, T stage, distant metastasis, VHL mutation and Ki-67 levels. CircPDHK1 had a functional internal ribosome entry site (IRES) and encoded a novel peptide PDHK1-241aa. Functionally, we confirmed that PDHK1-241aa and not the circPDHK1 promoted the proliferation, migration and invasion of ccRCC. Mechanistically, circPDHK1 was activated by HIF-2A at the transcriptional level. PDHK1-241aa was upregulated and interacted with PPP1CA, causing the relocation of PPP1CA to the nucleus. This thereby inhibited AKT dephosphorylation and activated the AKT-mTOR signaling pathway.ConclusionsOur data indicated that circPDHK1-encoded PDHK1-241aa promotes ccRCC progression by interacting with PPP1CA to inhibit AKT dephosphorylation. This study provides novel insights into the multiplicity of circRNAs and highlights the potential use of circPDHK1 or PDHK1-241aa as a therapeutic target for ccRCC."

基金机构：Top Graduate Talent Cultivation Program of Chongqing Medical University; College of Pharmacy at Army Medical University

基金资助正文：We express our gratitude to Professor Qin Ouyang from the College of Pharmacy at Army Medical University and Professor Qianqian Zhao from the College of Pharmacy at Chongqing Medical University for generously providing the protein structure analyses.