PMID- 38360682 OWN - NLM STAT- MEDLINE DCOM- 20240219 LR - 20240228 IS - 1476-4598 (Electronic) IS - 1476-4598 (Linking) VI - 23 IP - 1 DP - 2024 Feb 15 TI - 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. PG - 34 LID - 10.1186/s12943-024-01940-0 [doi] LID - 34 AB - BACKGROUND: Clear 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. METHODS: The 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. RESULTS: CircPDHK1 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. CONCLUSIONS: Our 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. CI - (c) 2024. The Author(s). FAU - Huang, Bo AU - Huang B AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. AD - Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, 563006, P.R. China. FAU - Ren, Junwu AU - Ren J AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Ma, Qiang AU - Ma Q AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Yang, Feifei AU - Yang F AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Pan, Xiaojuan AU - Pan X AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Zhang, Yuying AU - Zhang Y AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Liu, Yuying AU - Liu Y AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Wang, Cong AU - Wang C AD - Department of Urology, Southwest Hospital, Army Medical University, Chongqing, 400038, P.R. China. FAU - Zhang, Dawei AU - Zhang D AD - Department of Urology, Southwest Hospital, Army Medical University, Chongqing, 400038, P.R. China. FAU - Wei, Ling AU - Wei L AD - Department of Urology, Southwest Hospital, Army Medical University, Chongqing, 400038, P.R. China. FAU - Ran, Lingyu AU - Ran L AD - Department of Kidney, Southwest Hospital, Army Medical University, Chongqing, 400038, P.R. China. FAU - Zhao, Hongwen AU - Zhao H AD - Department of Kidney, Southwest Hospital, Army Medical University, Chongqing, 400038, P.R. China. FAU - Liang, Ce AU - Liang C AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Wang, Xiaolin AU - Wang X AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Wang, Shiming AU - Wang S AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Li, Haiping AU - Li H AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Ning, Hao AU - Ning H AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Ran, Ai AU - Ran A AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. FAU - Li, Wei AU - Li W AD - Department of Pharmacy, Chongqing University Cancer Hospital, Chongqing, 400030, P.R. China. liwei.tmmu@163.com. FAU - Wang, Yongquan AU - Wang Y AD - Department of Urology, Southwest Hospital, Army Medical University, Chongqing, 400038, P.R. China. wangyongquan@aliyun.com. FAU - Xiao, Bin AU - Xiao B AD - College of Pharmacy, Chongqing Medical University, Chongqing, 400016, P.R. China. binxiaocqmu@cqmu.edu.cn. LA - eng GR - BJRC202105/Top Graduate Talent Cultivation Program of Chongqing Medical University/ GR - CSTC2020JCYJ-MSXMX0022/Natural Science Foundation of Chongqing/ GR - CSTC2020JCYJ-MSXMX0337/Natural Science Foundation of Chongqing/ GR - CSTB2022NSCQ-BHX0707/Postdoctoral Science Foundation of Chongqing/ GR - 82373001/National Natural Science Foundation of China/ GR - CQYC202005044/Chongqing Talents-Exceptional Young Talents Project/ GR - CSTB2022NSCQ-LZX0043/Chongqing Natural Science Foundation Innovation and Development Joint Fund/ GR - KJZD-K202100405/Science and Technology Research Project of Chongqing Municipal Education Commission/ GR - W0042/Future Medical Youth Innovation Team Project of Chongqing Medical University/ GR - CQMUDSTD202210/Graduate Tutor Team Construction Project of Chongqing/ PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20240215 PL - England TA - Mol Cancer JT - Molecular cancer JID - 101147698 RN - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt) RN - 0 (RNA, Circular) RN - EC 2.7.11.1 (TOR Serine-Threonine Kinases) RN - 0 (Peptides) RN - EC 3.1.3.16 (PPP1CA protein, human) RN - EC 3.1.3.16 (Protein Phosphatase 1) SB - IM MH - Animals MH - Mice MH - Humans MH - *Carcinoma, Renal Cell/metabolism MH - Proto-Oncogene Proteins c-akt/metabolism MH - RNA, Circular/genetics MH - Mice, Nude MH - In Situ Hybridization, Fluorescence MH - Cell Line, Tumor MH - Signal Transduction/genetics MH - *Kidney Neoplasms/genetics MH - TOR Serine-Threonine Kinases/metabolism MH - Cell Proliferation/genetics MH - Peptides/genetics MH - Gene Expression Regulation, Neoplastic MH - Protein Phosphatase 1/genetics/metabolism PMC - PMC10870583 OTO - NOTNLM OT - CircPDHK1 OT - Clear cell renal cell carcinoma OT - Dephosphorylation OT - Novel peptide OT - PPP1CA COIS- The authors declare no competing interests. EDAT- 2024/02/16 00:42 MHDA- 2024/02/19 06:42 PMCR- 2024/02/15 CRDT- 2024/02/15 23:39 PHST- 2023/10/03 00:00 [received] PHST- 2024/01/12 00:00 [accepted] PHST- 2024/02/19 06:42 [medline] PHST- 2024/02/16 00:42 [pubmed] PHST- 2024/02/15 23:39 [entrez] PHST- 2024/02/15 00:00 [pmc-release] AID - 10.1186/s12943-024-01940-0 [pii] AID - 1940 [pii] AID - 10.1186/s12943-024-01940-0 [doi] PST - epublish SO - Mol Cancer. 2024 Feb 15;23(1):34. doi: 10.1186/s12943-024-01940-0.