1. 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

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

3. Macrophages polarization
M1-like
M2-like

5. 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.

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

7. 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)

8. 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:
THP-1 (ASC speckles)

9. 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 Jun 1;71(11):
Nat Med Jun;18(6):883-91

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

11. miR-21 is enriched in cancer-secreted exosomes

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

13. miR-21 is regulated by Snail

14. 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:
CD14+ monocyte
cytokine array
ELISA

15. 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

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

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

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

20. miR-21 targets the K63-specific deubiquitinase BRCC3

21. Chemotherapy and Inflammasome activation

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

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

25. Snail limits chemotherapy induced NLRP3 inflammasome activation in HNSCC patients

26. CD68: macrophage marker
PLA: NLRP3 and ASC interaction

28. 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.