c-Met identifies a population of matrix metalloproteinase 9-producing monocytes in peritumoural stroma of hepatocellular carcinoma
Macrophages (Mϕ) are prominent components of solid tumours and exhibit distinct phenotypes in different microenvironments. Previously, we found that tumours could alter the normal developmental process of Mϕ to trigger transient activation of monocytes in the peritumoural stroma of human hepatocellu...
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| Published in | The Journal of pathology Vol. 237; no. 3; pp. 319 - 329 |
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| Main Authors | , , , , , |
| Format | Journal Article |
| Language | English |
| Published |
Chichester, UK
John Wiley & Sons, Ltd
01.11.2015
Wiley Subscription Services, Inc |
| Subjects | |
| Online Access | Get full text |
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| Summary: | Macrophages (Mϕ) are prominent components of solid tumours and exhibit distinct phenotypes in different microenvironments. Previously, we found that tumours could alter the normal developmental process of Mϕ to trigger transient activation of monocytes in the peritumoural stroma of human hepatocellular carcinoma (HCC). In the present study, we showed that a fraction of monocytes in the peritumoural stroma, but not in HCC cancer nests, expressed surface c‐Met molecules. Monocytes exposed to tumours strongly expressed c‐Met proteins with kinetics similar to their activation status, and significant correlations were found between c‐Met levels and HLA‐DR expression on tumour‐infiltrating monocytes. NF‐κB‐mediated autocrine TNF‐α stimulated the expression of c‐Met on activated monocytes, and by interacting with its ligand hepatocyte growth factor (HGF), c‐Met increased the motility and matrix metalloproteinase (MMP) 9‐producing capacity of tumour‐associated monocytes. The intensity of c‐Met expression on tumour‐infiltrating monocytes was associated with high mortality and reduced survival of patients with HCC. Therefore, the expression of c‐Met on activated monocytes/Mϕ may represent a novel mechanism by which a tumour actively and precisely regulates the distribution and functions of these cells to facilitate disease progression. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. |
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| Bibliography: | ark:/67375/WNG-PDCVQPMH-3 Appendix S1. Supplementary materials and methodsFigure S1. mRNA levels of c-Met are increased in tumour-infiltrating monocytes. Monocytes were purified from non-tumour or tumour tissues of 7 patients with HCC. Levels of c-Met expression were analyzed by RT-PCR.Figure S2. CD68+c-Met+ monocytes are enriched in the peritumoural stroma of HCC patients. Distribution of CD68+c-Met+ monocytes in the peritumoural stroma of HCC samples was analyzed by confocal microscopy. Red: CD68, Green: c-Met. One out of 10 representative micrographs is shown.Figure S3. Expression of c-Met on tumour cells shows no correlation with either OS or DFS of HCC patients. Serial sections of paraffin-embeded tissues were stained with anti-c-Met antibody. (A) Tumour cells showed different levels of c-Met expression. (B) Patients with follow-up data were divided into two groups (Group 1: tumour cells showed no expression of c-Met; n = 49; Group 2: tumour cells showed different levels of c-Met expression; n = 74). Cumulative OS and DFS time were calculated using the Kaplan-Meier method and analyzed by the log-rank test. Red lines, positive staining of c-Met; blue lines, negative staining of c-Met.Figure S4. Erk and AKT signalling pathways are partially involved in the regulation of c-Met expression on TSN-exposed monocytes. Healthy PBMC-derived monocytes were pretreated with medium (Med), DMSO, DMSO-dissolved U0126, DMSO-dissolved LY294002 (LY), or DMSO-dissolved SP600125 (SP) for 30 min, and then incubated with medium or SK TSN for 15 min (A) or 16 hours (B). Levels of p-Erk, t-Erk, p-AKT, t-AKT, p-JNK, and t-JNK were determined by western blotting. Levels of c-Met expression were detected by FACS. Data shown are representative of at least three separate experiments.Figure S5. HGF production and distribution of fibroblasts and neutrophils in HCC tissues. (A) Monocytes (MO), neutrophils (Neu), fibroblasts (Fibro), and the remaining cells (RCs) were isolated from fresh HCC tissues (n = 5). Cells were cultured for 12 hours in vitro and the production of HGF was determined by ELISA. (B) Accumulation of fibroblasts and neutrophils in the peritumoural stroma of human HCC. Sections of paraffin-embedded HCC samples were stained with anti-human-CD15 or anti-human-α-SMA Ab. One out of 10 representative micrographs is shown.Figure S6. Workflow of the mouse experiments. i.v., intravenous.Figure S7. A scheme illustrating the interactions between tumour cells, stromal cells, and monocytes. ①Tumour-derived soluble factors activated peritumoural monocytes to produce large amounts of cytokines, including TNF-α. ②Autocrine TNF-α induced the expression of c-Met on activated monocytes. ③Stromal cell-derived HGF interacted with c-Met on peritumoal monocytes. ④c-Met+ monocytes accumulated in peritumoural stroma of HCC and produced large amounts of MMP9 to facilitate tumour progression.Table S1. Characteristics of the 149 clinical samplesTable S2. Proteins differentially expressed between medium- and SK-TSN-treated monocytes istex:6AA9339F0F566582370C7641F7084A1B168CCBBB ArticleID:PATH4578 National Natural Science Foundation of China - No. 81472644; No. 81230073; No. 91442205 Ministry of Health of China - No. 2012ZX10002-011 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0022-3417 1096-9896 |
| DOI: | 10.1002/path.4578 |