Correlation analysis between tumor-associated macrophages and epithelial-mesenchymal transition in cutaneous malignant melanoma

Abstract

Objective To investigate the relationship of tumor-associated macrophage (TAM) infiltration in lesions with clinicopathologic features of cutaneous malignant melanoma (CMM) and epithelial-mesenchymal transition (EMT) -related indicators. Methods Fifty-four CMM and 15 benign melanocytic nevus paraffin-embedded tissue samples were collected. An immunohistochemical study was performed to determine the expression pattern and intensity of the TAM marker CD163 as well as EMT indicators epithelial cadherin (E-cadherin) , neurologic cadherin (N-cadherin) and vimentin in these tissue samples. Count data were expressed as mean ± standard deviation. Statistical analysis was carried out using t test, one-way analysis of variance (ANOVA) and multivariate linear regression analysis with the software SPSS 17.0. Results CD163-positive TAMs were detected in CMM samples, but not in benign melanocytic nevus samples. The mean TAM count per high power field in tissue samples was significantly different between invasive and in situ CMM (35.08 ± 13.78 vs. 16.97 ± 8.74, P 0.05) . No significant difference was observed in TAM count between patients of different gender or age groups, between acral and non-acral melanoma, or between ulcerated and non-ulcerated melanoma (all P ≥ 0.05) . Multivariate linear regression analysis showed that TAM count in CMM was associated with five factors: Clark level, ulceration, tumor progression, N-cadherin and vimentin. Conclusion TAMs may accelerate tumor progression and increase tumor malignancy by promoting EMT in CMM. Key words: Melanoma; Nevi and melanomas; Macrophages; Epithelial-mesenchymal transition; Pathology