biostudies-literatureKakoschky BDeutsche ForschungsgemeinschaftUniversity of Frankfurt, Maria Christine Held and Erika Heckere0193015https://www.ebi.ac.uk/biostudies/studies/S-EPMC5814016biostudies-literatureUnknown13(2)Tumor progression largely depends on the presence of alternatively polarized (M2) tumor-associated macrophages (TAMs), whereas the classical M1-polarized macrophages can promote anti-tumorigenic immune responses. Thus, selective inhibition of M2-TAMs is a desirable anti-cancer approach in highly resistant tumor entities such as hepatocellular carcinoma (HCC) or breast cancer. We here examined whether a peptide that selectively binds to and is internalized by in vitro-differentiated murine M2 macrophages as compared to M1 macrophages, termed M2pep, could be used to selectively target TAMs in HCC and breast carcinoma. We confirmed selectivity of M2pep for in vitro M2 polarized macrophages. Upon incubation of suspended mixed 4T1 tumor cells with M2pep, high amounts of the TAMs were found to bPloS oneSelective targeting of tumor associated macrophages in different tumor models.PMC5814016GRK1172Schmithals CWeigert APleli TKorf HWVogl TJKakoschky BZeuzem SBrune BPiiper AfalseSelective targeting of tumor associated macrophages in different tumor models.Tumor progression largely depends on the presence of alternatively polarized (M2) tumor-associated macrophages (TAMs), whereas the classical M1-polarized macrophages can promote anti-tumorigenic immune responses. Thus, selective inhibition of M2-TAMs is a desirable anti-cancer approach in highly resistant tumor entities such as hepatocellular carcinoma (HCC) or breast cancer. We here examined whether a peptide that selectively binds to and is internalized by in vitro-differentiated murine M2 macrophages as compared to M1 macrophages, termed M2pep, could be used to selectively target TAMs in HCC and breast carcinoma. We confirmed selectivity of M2pep for in vitro M2 polarized macrophages. Upon incubation of suspended mixed 4T1 tumor cells with M2pep, high amounts of the TAMs were found to b2018-01-01T00:00:00Z20182025-05-29T22:10:11.233Z2025-05-29T22:10:11.233ZS-EPMC58140162944724110.1371/journal.pone.0193015