Nucleotide-binding domain of phosphoglycerate kinase 1 reduces tumor growth by suppressing COX-2 expression.
Phosphoglycerate kinase 1 (PGK-1) is a multifunctional protein that is involved in the glycolytic pathway and the generation of the angiogenesis inhibitor angiostatin. In a previous study, we showed that the overexpression of full-length PGK-1 in Lewis lung carcinoma (LLC-1) can reduce tumor growth in vivo by downregulation of COX-2 expression. Phosphoglycerate kinase 1 has two functional domains: a catalytic domain (CD); and a nucleotide-binding domain (NBD). To identify the functional domain of PGK-1 responsible for its antitumor effects, we evaluated the tumorigenicity of LLC-1 cells overexpressing full-length PGK-1 (LLC-1/PGK), CD (LLC-1/CD), and NBD (LLC-1/NBD). Although no difference in tumor cell growth was observed in vitro, the tumor invasiveness was reduced in the LLC-1/PGK, LLC-1/CD, and LLC-1/NBD cells compared to parental LLC-1 cells in vivo. In addition, in vivo tumor growth retardation by LLC-1/CD and LLC-1/NBD cells was observed, similar to that by LLC-1/PGK cells. However, the reduced stability of COX-2 mRNA and downregulation of the COX-2 protein and its metabolite, prostaglandin E2, was only found in LLC-1/PGK and LLC-1/NBD cells. Low levels of COX-2 were also observed in the tumor mass formed by the modified cells when injected into mice. The results indicate that COX-2 suppression by PGK-1 is independent of its catalytic activity. COX-2 targeting by PGK-1 can be attributed to its NBD and is probably a result of the destabilization of COX-2 gene transcripts brought about by the mRNA-binding property of PGK-1.
Ho
Ming-Yi
MY
Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Department of Education and Research, Taipei City Hospital, Taipei, Taiwan.
Tang
Shye-Jye
SJ
Ng
Wailap V
WV
Yang
Winnie
W
Leu
Shr-Jeng J
SJ
Lin
Ying-Chun
YC
Feng
Chi-Kuang
CK
Sung
Jung-Sung
JS
Sun
Kuang-Hui
KH
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D018827:Carcinoma, Lewis Lung / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D015972:Gene Expression Regulation, Neoplastic; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009711:Nucleotides / Q000378:metabolism; D010735:Phosphoglycerate Kinase / Q000235:genetics / Q000378:metabolism*; D020871:RNA Stability; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D047368:Tumor Burden
D009711:Nucleotides; D053773:Transforming Growth Factor beta1; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; C528165:Pgk1 protein, mouse; D010735:Phosphoglycerate Kinase; D015232:Dinoprostone