Collagenolytic and gelatinolytic matrix metalloproteinases and their inhibitors in basal cell carcinoma of skin: comparison with normal skin

Abstract

Tissue from 54 histologically-identified basal cell carcinomas of the skin was obtained at surgery and assayed using a combination of functional and immunochemical procedures for matrix metalloproteinases (MMPs) with collagenolytic activity and for MMPs with gelatinolytic activity. Collagenolytic enzymes included MMP-1 (interstitial collagenase), MMP-8 (neutrophil collagenase) and MMP-13 (collagenase-3). Gelatinolytic enzymes included MMP-2 (72-kDa gelatinase A/type IV collagenase) and MMP-9 (92-kDa gelatinase B/type IV collagenase). Inhibitors of MMP activity including tissue inhibitor of metalloproteinases-1 and -2 (TIMP-1 and TIMP-2) were also assessed. All three collagenases and both gelatinases were detected immunochemically. MMP-1 appeared to be responsible for most of the functional collagenolytic activity while gelatinolytic activity reflected both MMP-2 and MMP-9. MMP inhibitor activity was also present, and appeared, based on immunochemical procedures, to reflect the presence of TIMP-1 but not TIMP-2. As a group, tumours identified as having aggressive-growth histologic patterns were not distinguishable from basal cell carcinomas with less aggressive-growth histologic patterns. In normal skin, the same MMPs were detected by immunochemical means. However, only low to undetectable levels of collagenolytic and gelatinolytic activities were present. In contrast, MMP inhibitor activity was comparable to that seen in tumour tissue. In previous studies we have shown that exposure of normal skin to epidermal growth factor in organ culture induces MMP up-regulation and activation. This treatment concomitantly induces stromal invasion by the epithelium (Varani et al (1995) Am J Pathol146: 210–217; Zeigler et al (1996 b) Invasion Metastasis16: 11–18). Taken together with these previous data, the present findings allow us to conclude that the same profile of MMP/MMP inhibitors that is associated with stromal invasion in the organ culture model is expressed endogenously in basal cell carcinomas of skin. © 2000 Cancer Research Campaign

Matrix metalloproteinases (MMPs) in fresh human prostate tumour tissue and organ-cultured prostate tissue: Levels of collagenolytic and gelatinolytic MMPs are low, variable and different in fresh tissue versus organ-cultured tissue

“…Tissue frozen in OCT was examined by immunoperoxidase staining for MMP-1, MMP-2, MMP-9 and MMP-13 expression as described previously (Varani et al, 2000). Briefly, frozen sections were mounted on glass slides coated with poly-L-lysine and stained using the ABC method (Vector Labs; Burlingame, CA).…”

“…Enzyme levels measured in vitro appear to primarily reflect production by nonmalignant components rather than malignant cells. Perhaps most interesting, overall levels of the collagenolytic and gelatinoltyic MMPs are low in prostate tissue relative to other tumours (for example, basal cell carcinomas of skin) that have been examined in the past with the same approaches (Varani et al, 2000). The lack of tissue destruction and the relatively low invasive potential of the majority of prostate tumours may be reflective of this.…”

“…Even after 6 days, however, there was only a low level of gelatin-hydrolytic activity and no measurable collagenhydrolytic activity. In past studies we used organ cultures of normal skin and malignant skin tumours (basal cell carcinomas) to help elucidate the role of collagenolytic and gelatinolytic MMPs in epithelial cell invasion (Varani et al, 2000). Compared to MMP levels observed in skin, levels of these enzymes in prostate are low.…”

“…Monoclonal antibodies to MMP-2, MMP-9 and MMP-13 were obtained from Oncogene Sciences (Cambridge, MA). Antibody specificity was established based on reactivity with purified MMPs in Western blots, reactivity with appropriately sized moieties in organ culture fluids and a lack of reactivity with other sized moieties in the same culture fluids (Varani et al, 2000). A mouse monoclonal IgG1 antibody (Oncogene Sciences) and a rabbit polyclonal IgG antibody (R & D Systems, Minneapolis, MN) were used as controls.…”

“…At the end of the 18-hour incubation period, samples were resolved by SDS-PAGE. The presence of active enzyme was determined, based on the disappearance of the parental α1(I) and α2(I) collagen (or gelatin) bands and the appearance of lower molecular weight fragments (Mulligan et al, 1993;Varani et al, 2000). …”