Histological characterization of tumor-associated macrophages in patients with different stages of hepatocellular carcinoma (HCC) (TUM4P.914)

Abstract

Abstract Tumor-associated macrophages, major leukocytes detected in tumor tissues, have been characterized as M2Mφ. Recently, M2Mφ have been classified into different subsets; M2aMφ, M2bMφ and M2cMφ. Therefore, in this study, the subset of M2Mφ present in tumor tissues of HCC patients was determined. Tumor tissues were obtained by liver biopsy and liver resection from patients with early and advanced stages of HCC. Paraffin embedded tissue specimens were stained for PE-conjugated anti-CD68 Ab. Also, the same tissue specimens were stained for FITC-conjugated anti-IL-12 Ab, PE-conjugated anti-IL-10 Ab, FITC-conjugated anti-CCL1 Ab, and FITC-conjugated anti-CD206 Ab. Stained histologic specimens were examined microscopically. In the results, large numbers of CD68+cells were predominantly present in the edge of the tumors. Large numbers of Mφ were not isolated from the tumor nests. CD68+cells isolated from advanced stage HCC patients were determined as IL-10+CD206+ cells, while a few numbers of these cells were demonstrated in the tumor tissues of early stage HCC patients. IL-10+CCL1+ cells and IL-12+CD68+ cells were not isolated from both advanced stage and early stage HCC patients. These results indicate that a majority of M2Mφ present in advanced stage HCC patients are M2aMφ and/or M2cMφ.