Snail-overexpressing cancer cells modulates tumor-associated macrophages through promoting M2 polarization and suppressing inflammasome activation Speaker: Chia-Hsin Hsieh (謝佳欣)1 Advisor: Dr. Muh-Hwa Yang (楊慕華)1,2,3,4,5,6 1 Institute of Biotechnology in Medicine, National Yang-Ming University, Taipei, Taiwan 2 Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan 3 Genomic Research Center, National Yang-Ming University, Taipei, Taiwan 4 Immunity and Inflammation Research Center, National Yang-Ming University, Taipei, Taiwan 5 Division of Hematology-Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan 6 Genomic Research Center, Academia Sinica, Taipei, Taiwan

CD14+ human monocytes THP1 CD14+ human monocytes * CCL2, CCL5 are responsible for recruiting TAMs Cancer Cell 2014; 26: 534-48

Macrophages polarization M1-like M2-like

However, whether acetylated Snail also participates in polarizing macrophages toward M2-like phenotype and suppresses the activity of inflammasome of M1 macrophage is unclear. Here, we investigated the impact of Snail-expressing cancer cells on the inflammasome activity of tumor-associated macrophages.

Inhibition of inflammasome activation by FaDu-Snail supernatant in monocyte-derived macrophages

Inhibition of ASC speckles formation and NLRP3-ASC interaction by FaDu-Snail supernatant in THP-1 and monocyte-derived macrophage monocyte-derived macrophage (PLA: ASC and NLRP3) THP-1 (ASC speckles)

The neutralization of Snail-induced cytokines (IL6, IL8, CCL2 and CCL5) had no effect on FS supernatant-suppressed ASC speckles We have identified that IL-6, IL-8, CCL2, and CCL5 are the major cytokines regulated by Snail. Cancer Cell 2014; 26: 534-48 THP-1 (ASC speckles)

Exosomes mediated signaling in tumor microenvironment Exosomes are cell-derived vesicles that are present in many biological fluids and cultured medium of cell cultures. The diameter of exosomes is 30~100 nm. Exosomes contain cell-specific payloads of proteins, lipids, and genetic material (mRNA, miRNA) that are transported to other cells, where they alter function and physiology. Cancer Res. 2011 Jun 1;71(11):3792-801 Nat Med. 2012 Jun;18(6):883-91

(PLA: ASC and NLRP3) Snail-expressing cancer cells-secreted exosomes suppress the activity of NLRP3 inflammasome in activated macrophages.

miR-21 is enriched in cancer-secreted exosomes

miR-21 indeed expresses in FaDu-Snail-derived exosomes FS exosomes

miR-21 is regulated by Snail

We previously have identified that the conditioned media from Snail-expressing cancer cells not only recruit macrophages to tumors through secreting CCL2 and CCL5, but also polarize them toward an M2-like phenotype. We herein investigated the major molecule(s) that mediate Snail-induce M2-like polarization. Cancer Cell 2014; 26: 534-48 CD14+ monocyte cytokine array ELISA

Snail-overexpressing cancer cells-secreted exosomes promotes M2 polarization CD14+ monocyte FV-exo or FS-exo in FV CM for 48 hr M1, M2 markers

FaDu-Snail-conditioned macrophages demonstrates a M2-like phenotype HUVEC

Inhibition of ASC-NLRP3 assembly by miR-21 (PLA: ASC and NLRP3) 293T

miR-21 regulates NLRP3 K63-ubiquitination for inhibiting NLRP3 inflammasome assembly THP-1

miR-21 targets the K63-specific deubiquitinase BRCC3

Chemotherapy and Inflammasome activation

Cisplatin-induced activation of the NLRP3 inflammasome in macrophages is suppressed by Snail (PLA: ASC and NLRP3)

CD8+ T cell infiltration miR-21 and IFN-g signature

Snail limits chemotherapy induced NLRP3 inflammasome activation in HNSCC patients

CD68: macrophage marker PLA: NLRP3 and ASC interaction

Summary Snail-overexpressing cancer cells modulates myeloid cells/macrophages activity through the following mechanisms: CCL2/CCL5 recruit M2 macrophages (Hsu et al., Cancer Cell 2014). miR-21-containing exosomes promote M2 polarization (Hsieh et al., unpublished data). miR-21-containing exosomes repress NLRP3 inflammasome activity through targeting the NLRP3 deubiquitinase BRCC3 (Hsieh et al., unpublished data). Snail-modulated microenvironment blunts the host inflammatory responses during cancer treatment and course of disease progression.