Objective      To investigate the expression of cathepsin D (cath-D) and matrix metalloproteinase 9 (MMP-9) in cutaneous malignant melanoma (CMM)

junctional nevus and normal skin

and its relationship with the clinical stages and lymph node metastasis of CMM.       Methods      The expression of Cath-D and MMP-9 was detected in 44 cases of CMM

22 cases of junctional nevus and 20 cases of normal skin specimens by SP immunohistochemical method.       Results      The positive expression rates of Cath-D and MMP-9 in the CMM (79.55% and 75.00%) were higher than those in the junctional nevus (45.45% and 40.91%) and normal skin

(15.00% and 30.00%) (P0.05). The positive expression rates of Cath-D and MMP-9 in the CMM increased along with the increase in the depth of tumor invasion

and higher positive expression rates of Cath-D and MMP-9 were detected in the CMM patients with lymph node metastasis than in those without lymph node metastasis. There was a positive correlation between Cath-D and MMP-9 expression in the CMM tissues (r

s

=0.488

P0.05).       Conclusion      Cath-D and MMP-9 are important in the tumorigenesis and development of CMM and are closely related to CMM invasion and metastasis

with a possible synergistic effect. Combined detection of Cath-D and MMP-9 expression may help both early diagnosis and prognosis of CMM.