title: Glycosylphosphatidylinositol Anchor Modification Machinery Deficiency Is Responsible for the Formation of Pro-Prion Protein (PrP) in BxPC-3 Protein and Increases Cancer Cell Motility.
abstract: The normal cellular prion protein (PrP) is a glycosylphosphatidylinositol (GPI)-anchored cell surface glycoprotein. However, in pancreatic ductal adenocarcinoma cell lines, such as BxPC-3, PrP exists as a pro-PrP retaining its glycosylphosphatidylinositol (GPI) peptide signaling sequence. Here, we report the identification of another pancreatic ductal adenocarcinoma cell line, AsPC-1, which expresses a mature GPI-anchored PrP. Comparison of the 24 genes involved in the GPI anchor modification pathway between AsPC-1 and BxPC-3 revealed 15 of the 24 genes, including PGAP1 and PIG-F, were down-regulated in the latter cells. We also identified six missense mutations in DPM2, PIG-C, PIG-N, and PIG-P alongside eight silent mutations. When BxPC-3 cells were fused with Chinese hamster ovary (CHO) cells, which lack endogenous PrP, pro-PrP was successfully converted into mature GPI-anchored PrP. Expression of the individual gene, such as PGAP1, PIG-F, or PIG-C, into BxPC-3 cells does not result in phosphoinositide-specific phospholipase C sensitivity of PrP. However, when PIG-F but not PIG-P is expressed in PGAP1-expressing BxPC-3 cells, PrP on the surface of the cells becomes phosphoinositide-specific phospholipase C-sensitive. Thus, low expression of PIG-F and PGAP1 is the major factor contributing to the accumulation of pro-PrP. More importantly, BxPC-3 cells expressing GPI-anchored PrP migrate much slower than BxPC-3 cells bearing pro-PrP. In addition, GPI-anchored PrP-bearing AsPC-1 cells also migrate slower than pro-PrP bearing BxPC-3 cells, although both cells express filamin A. "Knocking out" PRNP in BxPC-3 cell drastically reduces its migration. Collectively, these results show that multiple gene irregularity in BxPC-3 cells is responsible for the formation of pro-PrP, and binding of pro-PrP to filamin A contributes to enhanced tumor cell motility.
authors.affiliation: From the Wuhan Institute of Virology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 44 Xiao Hong Shan Zhong Qu, Wuhan, 430071, China, the Department of Virology, School of Life Sciences, Wuhan University, State Key Laboratory of Virology, Wuhan, 430071, China.
authors.forename: Liheng
authors.initials: L
authors.lastname: Yang
authors.affiliation: From the Wuhan Institute of Virology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 44 Xiao Hong Shan Zhong Qu, Wuhan, 430071, China, the Department of Virology, School of Life Sciences, Wuhan University, State Key Laboratory of Virology, Wuhan, 430071, China.
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Gao
authors.affiliation: From the Wuhan Institute of Virology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 44 Xiao Hong Shan Zhong Qu, Wuhan, 430071, China.
authors.forename: Lipeng
authors.initials: L
authors.lastname: Hu
authors.affiliation: From the Wuhan Institute of Virology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 44 Xiao Hong Shan Zhong Qu, Wuhan, 430071, China.
authors.forename: Guiru
authors.initials: G
authors.lastname: Wu
authors.affiliation: the Department of the First Abdominal Surgery, Jiangxi Tumor Hospital, Nanchang 330029, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Yang
authors.affiliation: the Department of Pathology, Zhongda Hospital, Southeast University, Nanjing, 210009, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: the Department of Virology, School of Life Sciences, Wuhan University, State Key Laboratory of Virology, Wuhan, 430071, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: the Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Boon-Seng
authors.initials: BS
authors.lastname: Wong
authors.affiliation: the Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44102, and.
authors.forename: Wei
authors.initials: W
authors.lastname: Xin
authors.affiliation: the Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44102, and.
authors.forename: Man-Sun
authors.initials: MS
authors.lastname: Sy
authors.affiliation: the State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Hubei Collaborative Innovation Center for Industrial Fermentation, 44 Xiao Hong Shan Zhong Qu, Wuhan 430071, China cyli@wh.iov.cn.
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Li
mesh_terms: D000818:Animals; D016466:CHO Cells; D002465:Cell Movement; D006224:Cricetinae; D003412:Cricetulus; D064448:Filamins / Q000235:genetics / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational
chemical_list: D064448:Filamins; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C098069:PIGF protein, human; D011328:Prions; C484857:PGAP1 protein, human; D010744:Phosphoric Monoester Hydrolases
keywords: GPI anchor synthesis; cancer cell motility; cell migration; cell surface; glycosylphosphatidylinositol (GPI anchor); pancreatic cancer; pancreatic ductal adenocarcinoma cell; prion; prion protein