Clinical significance of RECK and MMP-9 expression in cutaneous squamous cell carcinoma

Abstract

Matrix metalloproteinase 9 (MMP-9) is recognized for its ability to promote tumor invasion and metastasis. However, its role and that of a novel regulator of MMP-9, reversion-inducing-cysteine-rich protein with kazal motifs (RECK), have not been explored in cutaneous squamous cell carcinoma (SCC). We investigated expression of MMP-9 and RECK in SCC to determine the clinical significance of their expression and potential uses for diagnostic, prognostic and therapeutic approaches. Immunohistochemistry was used to analyze expression in 36 SCC and 13 healthy skin samples collected at our hospital. RECK expression was detected in 33.3% of SCC samples, significantly fewer than for control samples (84.6%, P<0.05). In contrast, MMP-9 was expressed in 77.8% of SCC samples, significantly more than in control samples (30.8%, P<0.05). RECK and MMP-9 expression in SCC samples were negatively correlated (r = -0.406, P<0.05). Furthermore, negative RECK and positive MMP-9 expression in SCC tissues were correlated with differentiation degree and lymph node metastasis (P<0.05) but not with gender or age. Thus, low/absent expression of RECK and increased expression of MMP-9 correspond to increased disease severity. These proteins may play opposing roles in pathogenesis of SCC and may serve as future diagnostic or prognostic markers. Therefore RECK should be further investigated for therapeutic potential as an MMP-9 inhibitor.

Keywords: Cutaneous squamous cell carcinoma, RECK, MMP-9, immunohistochemistry, clinicopathological parameter