The Distribution of Macrophages with a M1 or M2 Phenotype in Relation to Prognosis and the Molecular Characteristics of Colorectal Cancer

• DOI: 10.1371/journal.pone.0047045
• Publication Date: 2012-10-15T21:43:12Z
• Authors: Sofia Edin; Maria L. Wikberg; Anna M. Dahlin; Jörgen Rutegård; Åke Öberg; Per-Arne Oldenborg; Richard Palmqvist
• Keywords: CD163; Microsatellite Instability; M2 Macrophage

High macrophage infiltration has been correlated to improved survival in colorectal cancer (CRC). Tumor associated macrophages (TAMs) play complex roles tumorigenesis since they are believed hold both tumor preventing (M1 macrophages) and promoting (M2 activities. Here we have applied an immunohistochemical approach determine the degree of infiltrating with a M1 or M2 phenotype clinical specimens CRC relation prognosis, general but also subgroups defined by microsatellite instability (MSI) screening status CpG island methylator (CIMP). A total 485 consecutive were stained for nitric oxide synthase 2 (NOS2) (also denoted iNOS) as marker scavenger receptor CD163 phenotype. The average NOS2 expressing along invasive front was semi-quantitatively evaluated using four-graded scale. Two subtypes macrophages, displaying (NOS2+) (CD163+) phenotypes, recognized. We observed significant correlation between amount NOS2+ CD163+ cells (P<0.0001). strong inverse stage found (P<0.0001) infiltration. Furthermore, patients harbouring tumors highly infiltrated had significantly better prognosis than those few cells, this be independent MSI CIMP status. No difference on cancer-specific groups different NOS2/CD163 ratios. In conclusion, increased at is accompanied concomitant increase phenotype, dependent manner CRC.