Western blot analysis revealed the presence of collagenase-3 protein in those carcinomas with high levels of mRNA expression, whereas no protein was detected in the carcinomas with negative mRNA expression, or in any of the normal tissues.
Collagenase 3 (MMP-13) is a recently identified member of the matrix metalloproteinase (MMP) gene family that is expressed at high levels in diverse human carcinomas and in articular cartilage from arthritic patients.
MMP-13 mRNAs were detected in 9 of 11 cell lines established from vulvar carcinomas and in 4 of 6 cell lines from cervical carcinomas, whereas endometrial (n = 10) and ovarian (n = 9) carcinoma cell lines were negative forMMP-13 mRNA.
The tumour/normal (T/N) ratios of collagenase-3 and MT1-MMP mRNA expression in 45 human oesophageal carcinomas were determined by northern blot analysis.
Western blot analysis revealed the presence of MMP-13 protein in those cell lines and carcinomas that expressed its mrna. on zymography, almost all cell lines that expressed MMP-13 showed gelatinolytic bands corresponding to the active form of MMP-13 or one of its intermediate forms.
Furthermore, human squamous cell carcinomas of the tongue with high expression of alphavbeta6 showed lower MMP-13 levels than carcinomas with low levels of alphavbeta6.