Figure 1. MT3-MMP is expressed in melanoma lymph node metastases and metastatic cell lines.

MT3-MMP (A) and MT1-MMP (B) mRNA expression levels in human tissue biopsies from normal skin (n = 8), nevus (n = 11), and melanoma metastases (n = 77) were assessed by qPCR. cDNAs were normalized against beta-actin. Soft tissue comprise metastases obtained from subcutaneous tissue of groin (n = 2), pelvis (n = 1) and thigh (n = 1). Other organs comprise single or double biopsies from melanoma metastases to skin, stomach, liver, mediastinum, ovary, kidney and brain. *p = 0.028 (p = 0.031 if the highest outlying lymph node metastasis value of 84.4 is excluded). (C) Relative values of average MT1-, MT2- and MT3-MMP mRNA expression were analyzed by qPCR in 7 melanoma cell lines as indicated. (D) The melanoma cells were embedded inside 3D collagen type I gels. After 4-d culture, the 3D cell/matrix constructs were fixed and stained with TRITC-phalloidin (red) and DAPI (blue). Fluorescence micrographs of the collagen gels show representative cell colonies.