Cell membrane-associated MT1-MMP dependent activation of MMP-2 in SiHa (human cervical cancer) cells.
Among the soluble MMPs, MMP-2 (gelatinase A) is particularly important in the invasive property of tumor cells. Cell membrane-associated MMP-2 activation is one of the challenging areas in tumor biology. In the present communication, we studied the membrane dependent activation of MMP-2 in SiHa cells.


METHODS
Activation of pro-MMP-2 by membrane fraction, membrane extract, and live SiHa cells was studied by gelatin zymography. The role of MT1-MMP in MMP-2 activation was studied by incubating SiHa cells and cell membrane fractions with anti-MT1-MMP antibody.


RESULTS
Activation of purified pro-MMP-2 by membrane fraction isolated from SiHa cells, by SiHa cell membrane extract and by SiHa cells, pro-MMP-2 from Con A treated HT-1080 conditioned medium by SiHa cells, and pro-MMP-2 from serum free culture medium of SiHa cells and cervical tissue homogenate by SiHa cell membrane fraction was shown by gelatin zymography. SiHa membrane fraction activated only pro-MMP-2 from purified MMP-9/MMP-2 mixture, indicating that the activation is specific for MMP-2. Inhibition of MMP-2 activation in the presence of anti-MT1-MMP antibody strongly indicated that the cell membrane mediated MMP-2 activation is MT1-MMP dependent. Immunocytochemistry of SiHa cells demonstrated expression of MT1-MMP at focal points. Invasion assay showed that invasiveness of anti-MT1-MMP antibody treated SiHa cells through Matrigel was drastically reduced compared to control SiHa cells.


CONCLUSIONS
Our findings furnish an example of the cell membrane-associated MT1-MMP mediated MMP-2 activation in SiHa cells and suggest that this MT1-MMP mediated MMP-2 activation is of importance in tumor invasion and metastasis. This MT1-MMP mediated MMP-2 activation on tumor cell surface could be a realistic target for managing metastatic diseases.
Mitra
Aparna
A
Department of Receptor Biology and Tumor Metastasis, Chittaranjan National Cancer Institute, 37 S.P. Mukherjee Road, Kolkata-700 026, India.
Chakrabarti
Jayati
J
Banerji
Aniruddha
A
Chatterjee
Amitava
A
D002458:Cell Fractionation; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000201:enzymology*; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D002583:Uterine Cervical Neoplasms / Q000201:enzymology / Q000473:pathology
D020778:Matrix Metalloproteinase 2; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14