Limits...
Lung tumor exosomes induce a pro-inflammatory phenotype in mesenchymal stem cells via NFκB-TLR signaling pathway.

Li X, Wang S, Zhu R, Li H, Han Q, Zhao RC - J Hematol Oncol (2016)

Bottom Line: Secretion of inflammation-associated cytokines in exosome-treated MSCs were analyzed by RT-PCR and ELISA.The growth-promoting effect of exosome-treated MSCs on lung tumor cells was evaluated by in vivo mouse xenograft model.We further found that Hsp70 present on the surface of lung tumor exosomes contributed to the induction of P-MSCs by A549 exosomes.

View Article: PubMed Central - PubMed

Affiliation: Center of Excellence in Tissue Engineering, Key Laboratory of Beijing, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.

ABSTRACT

Background: In tumor microenvironment, a continuous cross-talk between cancer cells and other cellular components is required to sustain tumor progression. Accumulating evidence suggests that exosomes, a novel way of cell communication, play an important role in such cross-talk. Exosomes could facilitate the direct intercellular transfer of proteins, lipids, and miRNA/mRNA/DNAs between cells. Since mesenchymal stem cells (MSCs) can be attracted to tumor sites and become an important component of the tumor microenvironment, there is an urgent need to reveal the effect of tumor exosomes on MSCs and to further explore the underlying molecular mechanisms.

Methods: Exosomes were harvested from lung cancer cell line A549 and added to MSCs. Secretion of inflammation-associated cytokines in exosome-treated MSCs were analyzed by RT-PCR and ELISA. The growth-promoting effect of exosome-treated MSCs on lung tumor cells was evaluated by in vivo mouse xenograft model. Signaling pathway involved in exosomes-treated MSCs was detected by PCR array of human toll-like receptor signaling pathway, RT-PCR, and Western blot.

Results: Data showed that lung tumor cell A549-derived exosomes could induce a pro-inflammatory phenotype in MSCs named P-MSCs, which have significantly elevated secretion of IL-6, IL-8, and MCP-1. P-MSCs possess a greatly enhanced ability in promoting lung tumor growth in mouse xenograft model. Analysis of the signaling pathways in P-MSCs revealed a fast triggering of NF-κB. Genetic ablation of Toll-like receptor 2 (TLR2) by siRNA and TLR2-neutralizing antibody could block NF-κB activation by exosomes. We further found that Hsp70 present on the surface of lung tumor exosomes contributed to the induction of P-MSCs by A549 exosomes.

Conclusions: Our studies suggest a novel mechanism by which lung tumor cell-derived exosomes induce pro-inflammatory activity of MSCs which in turn get tumor supportive characteristics.

No MeSH data available.


Related in: MedlinePlus

A549 cells derived exosomes significantly stimulate inflammatory cytokines production in MSCs. a Cytokine secretion profile of MSCs and exosomes-treated MSCs. MSCs were incubated with 200ug/ml exosomes for 24 h. b, c The mRNA level and protein level of IL-6, IL-8, and MCP-1 at different time points across a concentration gradient of exosomes (0, 100, 200, 400 μg/ml). d The mRNA expression changes of IL-6, IL-8 and MCP-1of MSCs treated with exosomes-depleted A549 cells culture medium (*P < 0.05, **P < 0.01, ***P < 0.001)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4836087&req=5

Fig2: A549 cells derived exosomes significantly stimulate inflammatory cytokines production in MSCs. a Cytokine secretion profile of MSCs and exosomes-treated MSCs. MSCs were incubated with 200ug/ml exosomes for 24 h. b, c The mRNA level and protein level of IL-6, IL-8, and MCP-1 at different time points across a concentration gradient of exosomes (0, 100, 200, 400 μg/ml). d The mRNA expression changes of IL-6, IL-8 and MCP-1of MSCs treated with exosomes-depleted A549 cells culture medium (*P < 0.05, **P < 0.01, ***P < 0.001)

Mentions: In our previous report about mRNA expression microarray [19], we noticed a remarkable elevation of genes associated with inflammation. Given the important link between inflammation and cancer progression, we began to explore whether A549 exosomes could change inflammatory response in MSCs. MSCs were exposed to 200 ug/ml A549 exosomes for 24 h, and the cytokine secretion profile of exosome-treated MSCs were detected by ELISA. Enhanced release of IL-6, IL-8, and MCP-1 was shown (Fig. 2a). To examine whether enhanced release of cytokines in exosome-treated MSCs was time- or concentration-dependent; we treated MSCs with different concentrations of A549 exosomes for 24 and 48 h. As shown in Fig. 2b for cytokine mRNA expression or Fig. 2c for cytokine protein release, no obvious time- or concentration-dependent manner was observed. To further confirm that the enhanced release of these cytokines was caused by exosome, we treated MSCs with exosome-depleted culture medium. As expected, enhanced expression of IL-6, IL-8, and MCP-1 was not observed (Fig. 2d). These data suggest that after exposure to cancer cell-derived exosomes, a new kind of pro-inflammatory MSCs (P-MSC) was generated.Fig. 2


Lung tumor exosomes induce a pro-inflammatory phenotype in mesenchymal stem cells via NFκB-TLR signaling pathway.

Li X, Wang S, Zhu R, Li H, Han Q, Zhao RC - J Hematol Oncol (2016)

A549 cells derived exosomes significantly stimulate inflammatory cytokines production in MSCs. a Cytokine secretion profile of MSCs and exosomes-treated MSCs. MSCs were incubated with 200ug/ml exosomes for 24 h. b, c The mRNA level and protein level of IL-6, IL-8, and MCP-1 at different time points across a concentration gradient of exosomes (0, 100, 200, 400 μg/ml). d The mRNA expression changes of IL-6, IL-8 and MCP-1of MSCs treated with exosomes-depleted A549 cells culture medium (*P < 0.05, **P < 0.01, ***P < 0.001)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4836087&req=5

Fig2: A549 cells derived exosomes significantly stimulate inflammatory cytokines production in MSCs. a Cytokine secretion profile of MSCs and exosomes-treated MSCs. MSCs were incubated with 200ug/ml exosomes for 24 h. b, c The mRNA level and protein level of IL-6, IL-8, and MCP-1 at different time points across a concentration gradient of exosomes (0, 100, 200, 400 μg/ml). d The mRNA expression changes of IL-6, IL-8 and MCP-1of MSCs treated with exosomes-depleted A549 cells culture medium (*P < 0.05, **P < 0.01, ***P < 0.001)
Mentions: In our previous report about mRNA expression microarray [19], we noticed a remarkable elevation of genes associated with inflammation. Given the important link between inflammation and cancer progression, we began to explore whether A549 exosomes could change inflammatory response in MSCs. MSCs were exposed to 200 ug/ml A549 exosomes for 24 h, and the cytokine secretion profile of exosome-treated MSCs were detected by ELISA. Enhanced release of IL-6, IL-8, and MCP-1 was shown (Fig. 2a). To examine whether enhanced release of cytokines in exosome-treated MSCs was time- or concentration-dependent; we treated MSCs with different concentrations of A549 exosomes for 24 and 48 h. As shown in Fig. 2b for cytokine mRNA expression or Fig. 2c for cytokine protein release, no obvious time- or concentration-dependent manner was observed. To further confirm that the enhanced release of these cytokines was caused by exosome, we treated MSCs with exosome-depleted culture medium. As expected, enhanced expression of IL-6, IL-8, and MCP-1 was not observed (Fig. 2d). These data suggest that after exposure to cancer cell-derived exosomes, a new kind of pro-inflammatory MSCs (P-MSC) was generated.Fig. 2

Bottom Line: Secretion of inflammation-associated cytokines in exosome-treated MSCs were analyzed by RT-PCR and ELISA.The growth-promoting effect of exosome-treated MSCs on lung tumor cells was evaluated by in vivo mouse xenograft model.We further found that Hsp70 present on the surface of lung tumor exosomes contributed to the induction of P-MSCs by A549 exosomes.

View Article: PubMed Central - PubMed

Affiliation: Center of Excellence in Tissue Engineering, Key Laboratory of Beijing, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.

ABSTRACT

Background: In tumor microenvironment, a continuous cross-talk between cancer cells and other cellular components is required to sustain tumor progression. Accumulating evidence suggests that exosomes, a novel way of cell communication, play an important role in such cross-talk. Exosomes could facilitate the direct intercellular transfer of proteins, lipids, and miRNA/mRNA/DNAs between cells. Since mesenchymal stem cells (MSCs) can be attracted to tumor sites and become an important component of the tumor microenvironment, there is an urgent need to reveal the effect of tumor exosomes on MSCs and to further explore the underlying molecular mechanisms.

Methods: Exosomes were harvested from lung cancer cell line A549 and added to MSCs. Secretion of inflammation-associated cytokines in exosome-treated MSCs were analyzed by RT-PCR and ELISA. The growth-promoting effect of exosome-treated MSCs on lung tumor cells was evaluated by in vivo mouse xenograft model. Signaling pathway involved in exosomes-treated MSCs was detected by PCR array of human toll-like receptor signaling pathway, RT-PCR, and Western blot.

Results: Data showed that lung tumor cell A549-derived exosomes could induce a pro-inflammatory phenotype in MSCs named P-MSCs, which have significantly elevated secretion of IL-6, IL-8, and MCP-1. P-MSCs possess a greatly enhanced ability in promoting lung tumor growth in mouse xenograft model. Analysis of the signaling pathways in P-MSCs revealed a fast triggering of NF-κB. Genetic ablation of Toll-like receptor 2 (TLR2) by siRNA and TLR2-neutralizing antibody could block NF-κB activation by exosomes. We further found that Hsp70 present on the surface of lung tumor exosomes contributed to the induction of P-MSCs by A549 exosomes.

Conclusions: Our studies suggest a novel mechanism by which lung tumor cell-derived exosomes induce pro-inflammatory activity of MSCs which in turn get tumor supportive characteristics.

No MeSH data available.


Related in: MedlinePlus