PCBP-1 regulates alternative splicing of the CD44 gene and inhibits invasion in human hepatoma cell line HepG2 cells.
BACKGROUND
PCBP1 (or alpha CP1 or hnRNP E1), a member of the PCBP family, is widely expressed in many human tissues and involved in regulation of transcription, transportation process, and function of RNA molecules. However, the role of PCBP1 in CD44 variants splicing still remains elusive.


RESULTS
We found that enforced PCBP1 expression inhibited CD44 variants expression including v3, v5, v6, v8, and v10 in HepG2 cells, and knockdown of endogenous PCBP1 induced these variants splicing. Invasion assay suggested that PCBP1 played a negative role in tumor invasion and re-expression of v6 partly reversed the inhibition effect by PCBP1. A correlation of PCBP1 down-regulation and v6 up-regulation was detected in primary HCC tissues.


CONCLUSIONS
We first characterized PCBP1 as a negative regulator of CD44 variants splicing in HepG2 cells, and loss of PCBP1 in human hepatic tumor contributes to the formation of a metastatic phenotype.
Zhang
Tong
T
Beijing Institute of Radiation Medicine, Beijing, 100850, China.
Huang
Xian-Hong
XH
Dong
Lan
L
Hu
Deqing
D
Ge
Changhui
C
Zhan
Yi-Qun
YQ
Xu
Wang-Xiang
WX
Yu
Miao
M
Li
Wei
W
Wang
Xiaohui
X
Tang
Liujun
L
Li
Chang-Yan
CY
Yang
Xiao-Ming
XM
D017398:Alternative Splicing; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D004268:DNA-Binding Proteins; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics* / Q000378:metabolism; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D018960:Hyaluronan Receptors; C094604:PCBP1 protein, human; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins