TY - JOUR
T1 - Blocking Interleukin (IL)4- and IL13-Mediated Phosphorylation of STAT6 (Tyr641) Decreases M2 Polarization of Macrophages and Protects Against Macrophage-Mediated Radioresistance of Inflammatory Breast Cancer
AU - Rahal, Omar M.
AU - Wolfe, Adam R.
AU - Mandal, Pijus K.
AU - Larson, Richard
AU - Tin, Sanda
AU - Jimenez, Cristina
AU - Zhang, Dadong
AU - Horton, Janet
AU - Reuben, James M.
AU - McMurray, John S.
AU - Woodward, Wendy A.
N1 - Publisher Copyright:
© 2017 The Authors
PY - 2018/3/15
Y1 - 2018/3/15
N2 - Purpose: To determine the role of macrophage polarization on the response of inflammatory breast cancer (IBC) cells to radiation and whether modulation of macrophage plasticity can alter radiation response. Methods and Materials: The human THP-1 monocyte cell line and primary human monocytes isolated from peripheral blood mononuclear cells were differentiated into macrophages and polarized to either an “antitumor” (M1) or a “protumor” (M2) phenotype. These polarized macrophages were co-cultured with IBC cells (SUM149, KPL4, MDA-IBC3, or SUM190) without direct contact for 24 hours, then subjected to irradiation (0, 2, 4, or 6 Gy). Interleukin (IL)4/IL13-induced activation of STAT6 signaling was measured by Western blotting of phospho-STAT6 (Tyr641), and expression of M2 polarization gene markers (CD206, fibronectin, and CCL22) was measured by quantitative polymerase chain reaction. Results: Expression of M2 polarization markers was higher in M2-polarized macrophages after IL4/IL13 treatment than in control (M0) or M1-polarized macrophages. Co-culture of IBC cell lines with M1-polarized THP-1 macrophages mediated radiosensitivity of IBC cells, whereas co-culture with M2-polarized macrophages mediated radioresistance. Phosphopeptide mimetic PM37, targeting the SH2 domain of STAT6, prevented and reversed IL4/IL13-mediated STAT6 phosphorylation (Tyr641) and decreased the expression of M2 polarization markers. Pretreatment of M2-THP1 macrophages with PM37 reduced the radioresistance they induced in IBC cells after co-culture. Targeted proteomics analysis of IBC KPL4 cells using a kinase antibody array revealed induction of protein kinase C zeta (PRKCZ) in these cells only after co-culture with M2-THP1 macrophages, which was prevented by PM37 pretreatment. KPL4 cells with stable short hairpin RNA knockdown of PRKCZ exhibited lower radioresistance after M2-THP1 co-culture. Conclusions: These data suggest that inhibition of M2 polarization of macrophages by PM37 can prevent radioresistance of IBC by down-regulating PRKCZ.
AB - Purpose: To determine the role of macrophage polarization on the response of inflammatory breast cancer (IBC) cells to radiation and whether modulation of macrophage plasticity can alter radiation response. Methods and Materials: The human THP-1 monocyte cell line and primary human monocytes isolated from peripheral blood mononuclear cells were differentiated into macrophages and polarized to either an “antitumor” (M1) or a “protumor” (M2) phenotype. These polarized macrophages were co-cultured with IBC cells (SUM149, KPL4, MDA-IBC3, or SUM190) without direct contact for 24 hours, then subjected to irradiation (0, 2, 4, or 6 Gy). Interleukin (IL)4/IL13-induced activation of STAT6 signaling was measured by Western blotting of phospho-STAT6 (Tyr641), and expression of M2 polarization gene markers (CD206, fibronectin, and CCL22) was measured by quantitative polymerase chain reaction. Results: Expression of M2 polarization markers was higher in M2-polarized macrophages after IL4/IL13 treatment than in control (M0) or M1-polarized macrophages. Co-culture of IBC cell lines with M1-polarized THP-1 macrophages mediated radiosensitivity of IBC cells, whereas co-culture with M2-polarized macrophages mediated radioresistance. Phosphopeptide mimetic PM37, targeting the SH2 domain of STAT6, prevented and reversed IL4/IL13-mediated STAT6 phosphorylation (Tyr641) and decreased the expression of M2 polarization markers. Pretreatment of M2-THP1 macrophages with PM37 reduced the radioresistance they induced in IBC cells after co-culture. Targeted proteomics analysis of IBC KPL4 cells using a kinase antibody array revealed induction of protein kinase C zeta (PRKCZ) in these cells only after co-culture with M2-THP1 macrophages, which was prevented by PM37 pretreatment. KPL4 cells with stable short hairpin RNA knockdown of PRKCZ exhibited lower radioresistance after M2-THP1 co-culture. Conclusions: These data suggest that inhibition of M2 polarization of macrophages by PM37 can prevent radioresistance of IBC by down-regulating PRKCZ.
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U2 - 10.1016/j.ijrobp.2017.11.043
DO - 10.1016/j.ijrobp.2017.11.043
M3 - Article
C2 - 29485045
AN - SCOPUS:85042508117
SN - 0360-3016
VL - 100
SP - 1034
EP - 1043
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 4
ER -