Fig 2: ELN increases human colon cancer epithelial cell proliferation and invasion. Human colon cancer epithelial cells (Caco-2) were seeded onto plates coated with recombinant ELN protein and cultured in medium with (or without) ELN peptide. Control plates were coated with PBS only. a Cell proliferation was assessed after 6, 12, 24 and 48 h incubation by MTT assay. b A straight scratch was performed in each well and cancer cells invasion and migration were assessed by wound healing. c Wound area was assessed by measuring the wound closure size after 6 and 12 h post scratch, scale bar is 200 µm. n = 4. Results are mean ± SEM. *P < 0.05, ***P < 0.001 compared to cells cultured in normal medium on control plates. ††† < 0.001, compared to cells cultured in medium contain ELN peptide on control plates. #P < 0.05 compared to cells cultured in normal medium on ELN coated plates

Fig 3: ELN induces epithelial mesenchymal transition (EMT) in human colon cancer epithelial cells. Human colon cancer epithelial cells (Caco-2) were seeded onto plates coated with recombinant elastin proteins. Control plates were coated with PBS only. Cells were cultured in medium with (or without) ELN peptide for 48 h a Total protein were collected from cell lysates and a-SMA, vimentin (VIM) and E-cadherin proteins were assessed by immunoblot. Fold change of densitometry of b a-SMA c VIM and d E-cadherin were normalized to ß-actin. n = 4, Results are mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 compared to cells cultured in normal media on control plates. ††† < 0.001, †††† < 0.0001 compared to cells cultured in medium containing ELN peptide on control plates. #P < 0.05, ##P < 0.01, ###P < 0.001 compared to cell cultured in normal medium on ELN coated plates. Uncropped blots were shown in Additional file 1: Fig. S4

Fig 4: ELN mRNA expression is increased in colorectal cancer (CRC) patients, and ELN protein is increased in colon cancer epithelial cells. aELN gene expression was analyzed from colon tissues from healthy controls (n = 5) and CRC patients (n = 31) based on a GSE128449 dataset. bELN gene expression was analyzed from colon tissues from tumor and adjacent non-tumor tissues from the same CRC patients (n = 17) according to a GSE110224 dataset. Colon cancer epithelial cells and normal colon epithelial cells were cultured. c ELN protein was assessed in cell lysates after 24 and 48 h incubation by immunoblot, and d fold change of densitometry normalized to ß-actin, n = 4. Results are mean ± SEM. *P < 0.05 compared to normal colon epithelial cells

Fig 5: TNF mRNA is increased in CRC patients and ELN recombinant protein increases TNF protein from bone marrow derived macrophages (BMDM) after LPS challenge. aTNF gene expression was analyzed from colon tissues from healthy controls (n = 5) and CRC patients (n = 31) based on a GSE128449 dataset. bTNF gene expression was analyzed from colon tissues from tumor and adjacent non-tumor tissues from the same CRC patients (n = 17) according to a GSE110224 dataset. c BMDM were isolated from mice and the purity of macrophages were assessed by flow cytometry. d BMDM were cultured on plates coated with recombinant ELN protein, and control plates were coated with PBS only. BMDM cell lysates were collected 24 and 48 h after LPS challenge, and TNF proteins measured by ELISA. n = 6. Results are mean ± SEM. **P < 0.01, ***P < 0.001 compared to control plates. #P < 0.05 compared to plates coated with LPS only