Elevated Plasma Levels of MT4-MMP and MT6-MMP; A New Observation in Patients with Thyroid Nodules

BACKGROUND

Based on the critical role of MT4-MMP and MT6-MMP in carcinogenesis, we focused on MT4-MMP and MT6-MMP circulating levels in patients with thyroid nodules.

METHODS

Plasma samples were collected from three groups, including papillary thyroid cancer (PTC; n=30), multinodular goiter (MNG; n=30), and healthy subjects (n=22). Enzyme-linked immunosorbent assay (ELISA) was used to obtain the concentration of MT4-MMP and MT6-MMP in the three groups.

RESULTS

Analysis of data demonstrated increased levels of MT4-MMP (PTC: 4.90±1.35, MNG: 4.89±1.37, and healthy: 3.13±1.42) and MT6-MMP (PTC: 8.29±2.50, MNG: 7.34±2.09, and healthy:5.01±2.13) in thyroid nodules by comparison with healthy subjects (P<0.05). There were no significant differences in the levels of the two MT-MMPs between PTC and MNG (P>0.05). Increased plasma levels of MT4-MMP (odds ratio=2.48; 95% CI: 1.46-4.19; P=0.001) or MT6-MMP (odds ratio=1.81; 95% CI: 1.29-2.53; P=0.001) were associated with increased risk of PTC tumorigenesis. Interestingly, a strong positive association was observed between MT4-MMP and MT6-MMP in the three groups (PTC: r=0.766**, P=0.000; MNG: r=0.856**, P=0.000; healthy r=0.947**, P=0.000). Areas under the ROC curve for MT4-MMP and MT6-MMP were 0.82 and 0.96, respectively. At the cutoff value>4.7 (ng/mL), MT4-MMP and MT6-MMP showed a sensitivity of 63.3% and 90.0%, respectively, with 100% specificity.

CONCLUSION

Our work has led us to imply that the higher levels of MT4-MMP and MT6-MMP are closely linked with both PTC and MNG tumorigenesis. They may probably promote the development of thyroid lesions; however, more research is needed to further clarify the current findings.

Mmp25β facilitates elongation of sensory neurons during zebrafish development

Matrix metalloproteinases (MMPs) are a large and complex family of zinc-dependent endoproteinases widely recognized for their roles in remodeling the extracellular matrix (ECM) during embryonic development, wound healing, and tissue homeostasis. Their misregulation is central to many pathologies, and they have therefore been the focus of biomedical research for decades. These proteases have also recently emerged as mediators of neural development and synaptic plasticity in vertebrates, however, understanding of the mechanistic basis of these roles and the molecular identities of the MMPs involved remains far from complete. We have identified a zebrafish orthologue of mmp25 (a.k.a. leukolysin; MT6-MMP), a membrane-type, furin-activated MMP associated with leukocytes and invasive carcinomas, but which we find is expressed by a subset of the sensory neurons during normal embryonic development. We detect high levels of Mmp25β expression in the trigeminal, craniofacial, and posterior lateral line ganglia in the hindbrain, and in Rohon-Beard cells in the dorsal neural tube during the first 48 h of embryonic development. Knockdown of Mmp25β expression with morpholino oligonucleotides results in larvae that are uncoordinated and insensitive to touch, and which exhibit defects in the development of sensory neural structures. Using in vivo zymography, we observe that Mmp25β morphant embryos show reduced Type IV collagen degradation in regions of the head traversed by elongating axons emanating from the trigeminal ganglion, suggesting that Mmp25β may play a pivotal role in mediating ECM remodeling in the vicinity of these elongating axons.