Objective The aim of this study was to investigate the co-operative role of HGF and IL-1ra in metastatic processes by interactions between colon cancer cells and stromal cells in their microenvironment.Methods Expression of IL-1α,HGF and c-Met mRNA and proteins were determined by RT-PCR and Western blot.The effect of HGF on metastatic potential was evaluated by proliferation,invasion,and angiogenesis assays using an in vitro system consisting of co-cultured tumor cells and stromal cells.Results IL-1α expression was closely correlated with metastatic potential,and cancer cell-derived IL-1α significantly promoted HGF expression by fibroblasts (P ＜ 0.01).HGF enhanced the migration and proliferation of human umbilical vein endothelial cells (HUVECs),and angiogenesis (P ＜ 0.01).The high liver-metastatic colon cancer cell line (HT-29),which secretes IL-1 α,significantly enhanced angiogenesis compared to the low liver-metastatic cell line (CaCo-2),which does not produce IL-1 α (P ＜ 0.01).IL-1 ra significantly inhibit migration,proliferation and angiogenesis (P ＜ 0.01).Conclusions Autocrine IL-1α and paracrine HGF enhance the metastatic potential of colon cancer cells;IL-1ra inhibit the metastatic potential of colon cancer cells by blocking IL-1α and HGF signaling pathways.

OBJECTIVETo explore the effect of colon cancer cell-derived interleukin-1α on the migration and proliferation of human umbilical vein endothelial cells as well as the role of IL-1α and IL-1ra in the angiogenesis process.

METHODSWestern blot was used to detect the expression of IL-1α and IL-1R1 protein in the colon cancer cell lines with different liver metastatic potential. We also examined how IL-1α and IL-1ra influence the proliferation and migration of umbilical vascular endothelial cells assessed by PreMix WST-1 assay and migration assay, respectively. Double layer culture technique was used to detect the effect of IL-1α on the proliferation and migration of vascular endothelial cells and the effect of IL-1ra on the vascular endothelial cells.

RESULTSWestern blot analysis showed that IL-1α protein was only detected in highly metastatic colon cancer HT-29 and WiDr cells, but not in the lowly metastatic CaCo-2 and CoLo320 cells.Migration assay showed that there were significant differences in the number of penetrated cells between the control (17.9±3.6) and 1 ng/ml rIL-1α group (23.2±4.2), 10 ng/ml rIL-1α group (31.7±4.5), and 100 ng/ml rIL-1α group (38.6±4.9), showing that it was positively correlated with the increasing concentration of rIL-1α (P<0.01 for all). The proliferation assay showed that the absorbance values were 1.37±0.18 in the control group, and 1.79±0.14 in the 1 ng/ml rIL-1α group, 2.14±0.17 in the 10 ng/ml rIL-1α group, and 2.21±0.23 in the 100 ng/ml rIL-1α group, showing a positive correlation with the increasing concentration of rIL-1α(P<0.01 for all). IL-1ra significantly inhibited the proliferation and migration of vascular endothelial cells (P<0.01). The levels of VEGF protein were (1.697±0.072) ng/ml, (3.507±0.064)ng/ml and (4.139±0.039)ng/ml in the control, HUVECs+ IL-1α and HUVECs+ HT-29 co-culture system groups, respectively, showing a significant difference between the control and HUVECs+ 10 pg/ml rIL-1α groups and between the control and HUVECs+ HT-29 groups (P<0.01 for both).

CONCLUSIONSOur findings indicate that colon cancer cell-derived IL-1α plays an important role in the liver metastasis of colon cancer through increased VEGF level of the colon cancer cells and enhanced vascular endothelial cells proliferation, migration and angiogenesis, while IL-1ra can suppress the effect of IL-1α and inhibit the angiogenesis in colon cancer.

Blotting, Western ; Caco-2 Cells ; Cell Line, Tumor ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Coculture Techniques ; Colonic Neoplasms ; blood supply ; metabolism ; pathology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Interleukin 1 Receptor Antagonist Protein ; metabolism ; physiology ; Interleukin-1alpha ; metabolism ; physiology ; Liver Neoplasms ; secondary ; Neovascularization, Pathologic ; etiology

Objective To explore the molecular genetic characteristics of primary and recurrent glioblastomas (GBMs) from the same patient in vivo, primary glioma stem cells cultured in vitro, and patient-derived xenograft (PDX). Methods (1) The primary and recurrent GBM specimens from one patient during surgical resection were collected; and the expressions of glial fibrillary acidic protein (GFAP), nestin and Ki-67 were detected by immunohistochemical staining; the methylation of O6-methylguanine DNA methyltransferase (MGMT) gene, mutation of isocitrate dehydrogenase (IDH) gene and amplification of epidermal growth factor receptor (EGFR) gene were analyzed. (2) The primary and recurrent GBM stem cells were cultured in vitro and named as SU5-1 and SU5-2 cells, respectively; the expressions of nestin and CD133 were detected by immunohistochemical staining; GFAP expression was detected by immunohistochemical staining after induced differentiation, and the growth curve was detected by CCK-8 assay; Transwell invasion assay was used to detect the invasion ability; cell resistance to temozolomide (TMZ), carboplatin (CBP), cisplatin (DDP) and adriamycin (ADM) was detected by CCK-8 assay; the protein expression of programmed death receptor-ligand 1 (PD-L1) was detected by Western blotting. The rate of PD-L1 positive cells was detected by flow cytometry; genetic testing analysis was as above. (3) The primary and recurrent in situ PDX models in nude mice were established, and the expressions of nestin, GFAP and Ki-67 were detected by immunohistochemical staining. Results (1) As compared with the primary GBM, the recurrent GBM had significantly higher percentages of Ki-67 and nestin positive cells, while statistically lower percentage of GFAP positive cells (P<0.05); genetic analysis showed that there was no mutation in IDH gene in the primary GBM tissues and recurrent GBM tissues; the MGMT gene in the primary GBM tissues was methylated and EGFR gene was not amplified, while the MGMT gene in recurrent GBM tissues was demethylated and EGFR gene amplification was positive. (2) Both SU5-1 and SU5-2 cells expressed nestin and CD133, and GFAP was expressed after induced differentiation; the growth curve showed that the proliferation of SU5-2 cells started earlier than that of SU5-1 cells, the two were equal on the 3rd, 4th, and 5th d, and the proliferation of SU5-1 cells was faster than that of SU5-2 cells from the 6th d; the invasion ability of SU5-2 cells was statistically stronger than that of SU5-1 cells (P<0.05); the inhibition rates of SU5-2 cells treated with 5, 10, and 15 mmol/L CBP, 0.3125, 1.25, and 5 mmol/L DDP, 0.5 and 2 mmol/L ADM, and 125 and 500 mmol/L TMZ were significantly lower than those of SU5-1 cells treated with the same concentrations and same drugs (P<0.05); the protein expression of PD-L1 in SU5-2 cells was higher than that in SU5-1 cells; the positive rate of PD-L1 in SU5-2 cells was statistically higher than that in SU5-1 cells (P<0.05); the results of genetic analysis were consistent with those of the primary and recurrent GBM samples. (3) As compared with those in the primary PDX model, the nestin and Ki-67 expressions were significantly higher and GFAP expression was significantly lower in the recurrent PDX model (P<0.05); the results of genetic analysis were consistent with those of the primary and recurrent GBM samples. Conclusions Genetic differences are detected between primary and recurrent GBMs; recurrent GBM has stronger invasive capacity and multi-drug resistance. The primary stem cells derived from surgical specimens and corresponding PDX models could replicate the molecular genetic characteristics of original tumors, which provide a reliable experimental platform for both tumor translation researches and screening of molecular therapeutic targets.