Differential roles of matrix metalloproteinase-9 and -2, depending on proliferation or differentiation of retinoblastoma cells.
OBJECTIVE
To investigate the differential roles of matrix metalloproteinase (MMP)-9 and MMP-2 in the proliferation or differentiation of retinoblastoma cells.


METHODS
Cell proliferation assay with an MMP-9 inhibitor and cell viability assay with an MMP-2 inhibitor were performed in retinoblastoma cells with 5 ng/mL fibroblast growth factor 2 for proliferation, 0.1% bovine serum albumin for differentiation, or reverse transcriptase-polymerase chain reaction (RT-PCR) for MMP-9, MMP-2, and their tissue inhibitors TIMP-1 and TIMP-2. Immunohistochemistry for MMP-2 and nm23 was performed using an experimental model of retinoblastoma. With the use of an MMP-2 inhibitor, Western blot analysis was performed for neurofilament, extracellular signal-regulated kinases 1 and 2 (ERK 1/2), and phospho-ERK 1/2, and neurite length was measured in differentiated retinoblastoma cells.


RESULTS
With the proliferation of retinoblastoma cells, MMP-9 expression was upregulated without alteration of MMP-2, TIMP-1, or TIMP-2. However, proliferation was not affected by the inhibition of MMP-9 activity. Interestingly, only MMP-2 expression, colocalized with differentiated cells in retinoblastoma tissue, was significantly increased in the differentiation of retinoblastoma cells. Inhibition of MMP-2 activity did not affect cellular viability but attenuated neurite outgrowth and neurofilament expression of differentiated retinoblastoma cells, which was mediated through the suppression of ERK 1/2 activation.


CONCLUSIONS
The authors suggest that differential expression of MMP-9 and -2 could reflect biological features, such as proliferation and differentiation, of retinoblastoma cells. In particular, MMP-2 could be directly involved in the regulation of differentiation of retinoblastoma cells. Therefore, therapeutic targeting to MMP-2 may prove useful for reducing malignancy through the differentiation of retinoblastoma cells.
Kim
Jeong Hun
JH
Fight Against Angiogenesis-Related Blindness Laboratory, Department of Ophthalmology, College of Medicine, Seoul National University, Seoul, Korea.
Kim
Jin Hyoung
JH
Cho
Chang Sik
CS
Jun
Hyoung Oh
HO
Kim
Dong Hun
DH
Yu
Young Suk
YS
Kim
Kyu-Won
KW
D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D049109:Cell Proliferation; D002470:Cell Survival; D004195:Disease Models, Animal; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000502:physiology*; D020780:Matrix Metalloproteinase 9 / Q000502:physiology*; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D048053:Mitogen-Activated Protein Kinase 6 / Q000378:metabolism; D054778:NM23 Nucleoside Diphosphate Kinases / Q000378:metabolism; D016501:Neurites / Q000502:physiology; D019572:Retinal Neoplasms / Q000201:enzymology* / Q000473:pathology; D012175:Retinoblastoma / Q000201:enzymology* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D014407:Tumor Cells, Cultured
D061965:Matrix Metalloproteinase Inhibitors; D054778:NM23 Nucleoside Diphosphate Kinases; D019715:Tissue Inhibitor of Metalloproteinase-1; D016222:Fibroblast Growth Factor 2; D019716:Tissue Inhibitor of Metalloproteinase-2; D012710:Serum Albumin, Bovine; D048052:Mitogen-Activated Protein Kinase 3; D048053:Mitogen-Activated Protein Kinase 6; C517938:NME1 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9