Intracellular co-localization of trypsin-2 and matrix metalloprotease-9: Possible proteolytic cascade of trypsin-2, MMP-9 and enterokinase in carcinoma

• Published in: Experimental cell research Vol. 314; no. 4; pp. 914 - 926
• Main Authors: Vilen, Suvi-Tuuli, Nyberg, Pia, Hukkanen, Mika, Sutinen, Meeri, Ylipalosaari, Merja, Bjartell, Anders, Paju, Annukka, Haaparanta, Virpi, Stenman, Ulf-Håkan, Sorsa, Timo, Salo, Tuula
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.02.2008; Elsevier BV
• Subjects: Bone Neoplasms - enzymology; Cancer; Cancer and Oncology; Cancer och onkologi; Carcinoma - enzymology; Carcinoma, Squamous Cell - enzymology; Carcinoma, Squamous Cell - genetics; Cell Line, Tumor; Cells; Cellular biology; Clinical Medicine; Enterokinase; Enteropeptidase - metabolism; Enzyme Precursors - metabolism; Enzymes; Humans; Intracellular vesicle; Klinisk medicin; Matrix Metalloproteinase 9 - analysis; Matrix Metalloproteinase 9 - metabolism; Medical and Health Sciences; Medicin och hälsovetenskap; MMP-9; Mouth Neoplasms - enzymology; Mouth Neoplasms - genetics; Oral carcinoma; Proteolysis; Trypsin - analysis; Trypsin - genetics; Trypsin - metabolism; Trypsin-2; Trypsinogen - analysis; Trypsinogen - genetics; Trypsinogen - metabolism; Tumors; Urologi och njurmedicin; Urology and Nephrology; PBS; Intracellular vesicle; Oral carcinoma; OSCC; Enterokinase; DAB; TAT; ECM; ECL; mAb; pAb; BSA; MMP; SDS-PAGE; Proteolysis; RT-PCR; Trypsin-2; APMA; MMP-9; AEC
• ISSN: 0014-4827; 1090-2422; 1090-2422
• DOI: 10.1016/j.yexcr.2007.10.025

Tumor-associated trypsin-2 and matrix metalloprotease-9 (MMP-9) are associated with cancer, particularly with invasive squamous cell carcinomas. They require activation for catalytical competence via proteolytic cascades. One cascade is formed by enterokinase, trypsin-2 and MMP-9; enterokinase activates trypsinogen-2 to trypsin-2, which is an efficient proMMP-9 activator. We describe here that oral squamous cell carcinomas express all members of this cascade: MMP-9, trypsin-2 and enterokinase. The expression of enterokinase in a carcinoma cell line not derived from the duodenum was shown here for the first time. Enterokinase directly cleaved proMMP-9 at the Lys 65-Ser 66 site, but failed to activate it in vitro. We demonstrated by confocal microscopy that MMP-9 and trypsin-2 co-localized in intracellular vesicles of the carcinoma cells. This co-localization of trypsin-2 and MMP-9 resulted in intracellular proMMP-9 processing that represented fully or partially activated MMP-9. However, although both proteases were present also in various bone tumor tissues, MMP-9 and trypsin-2 never co-localized at the cellular level in these tissues. This suggests that the intracellular vesicular co-localization, storage and possible activation of these proteases may be a unique feature for aggressive epithelial tumors, such as squamous cell carcinomas, but not for tumors of mesenchymal origin.