Abstract: HUANG Ying-xue, ZHOU Lu, ZHANG Wei, SHAO Xue-bao, LI A-mei, XU Xiu-lian，SUN Jian-fang. Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China Corresponding authors: XU Xiu-lian, Email: xxlqjl@sina.com; SUN Jian-fang, Email: fangmin5758@yahoo.com.cn 【Abstract】 Objective To detect the expression of tissue inhibitor of metalloproteinase-4（TIMP-4） in cutaneous malignant melanoma （CMM） tissue and to assess its relationship with melanoma proliferation, invasion and metastasis. Methods Western blot was conducted to measure the protein expression of TIMP-4 in five fresh lesional and paratumoral tissue specimens of CMM and three fresh tissue specimens of nevi. Immunohistochemistry was carried out to quantify the expression of TIMP-4, Ki-67, matrix metalloproteinase-2 （MMP-2）, vascular endothelial growth factor （VEGF） and CD63 in paraffin-embedded tissue samples from 43 cases of CMM and 51 cases of nevi. The degree of malignancy of melanoma was evaluated in these lesions. Results Western blot analysis showed that the expression of TIMP-4 was significantly higher in 4 of 5 CMM tissue specimens than in corresponding paratumoral tissue specimens and nevus tissue specimens. Immunohistochemistry revealed that the expression rate of TIMP-4 was 86.04% （37/43） in melanoma tissue, compared to 19.6% （10/51） in nevus tissue （χ2 = 31.55, P < 0.05）. The expression of TIMP-4 increased sequentially from in situ melanoma to invasive and metastatic melanoma （rs = 0.309, P < 0.05）. As far as CMM was concerned, the TIMP-4 expression was uncorrelated with any of the known prognostic variables including clinical stage, Clark level, Breslow depth, presence of ulcer, and Ki-67 expression （all P > 0.05）, but positively correlated with the expressions of VEGF （rs = 0.345, P < 0.05） and CD63 （rs = 0.555，P < 0.01）. The median expression level of TIMP-4 was significantly higher in MMP-2-positive than in MMP-2-negative melanoma tissue samples （3 vs. 0, P < 0.01）. Conclusions TIMP-4 protein is highly expressed in CMM tissue, which may be closely associated with the initiation and progression of CMM, especially with the metastasis of and angiogenesis in CMM. 【Key words】 Melanoma; Tissue inhibitor of metalloproteinases; Matrix metalloproteinases

Key words: Matrix metalloproteinases