Expression of PGE2 and COX-2 in colorectal cancer and the clinical significance / 中华普通外科杂志

Objective To investigate the expressions of PGE2 and COX-2 between colorectal cancer tissue and normal colorectal mucosa tissue,and its relation to clinical pathology and significance.Methods 115 colon cancerous tissues and 69 normal colon tissues were collected in our hospital from Jan 2010 to Sept 2011.Immunohistochemistry was used to detect the PGE2 and COX-2 expression in both of the colorectal cancer and normal tissues.Results Positive expressions of PGE2 and COX-2 were 87.8％ (101/115) and 80.9％ (93/115) in the colorectal cancer tissue,and 8.7％ (6/69),21.7％ (15/69) in normal colorectal mucosa tissue respectively (x2 =110.96,62.194,all P ＜ 0.05).Expressions of PGE2 and COX-2 were closely associated with,tumor invasion,differentiation,lymph node metastasis and TNM stage (P ＜ 0.05).The Spearman rank correlation analysis indicated that the PGE2 and COX-2 expressions in tissues were closely correlated (r =0.987,P ＜ 0.05).Survival rate of the patients in both negative expressions of PGE2 and COX-2 (63.6％) were higher than that of both positive expressions (37.8％,P ＜ 0.05).Conclusion High PGE2 and COX-2 expressions in colorectal cancer tissues predicts poor patients' survival.

CXCL12 promotes CXCL8 secretion and co-operatively enhance metastatic potential of colon cancer cell lines / 中华普通外科杂志

Objective To investigate the effect of CXCL12 on the secretion of CXCL8 from colon cancer cells and the mechanism of co-regulation of proliferation and metastasis of colon cancer.Methods The expression levels of CXCL8 and CXCl12 in 5 human colon cancer cell lines (DLD-1,HT29,WiDr,CaCo-2,Colo320),fibroblasts,and human umbilical vein endothelial cells (HUVEC) were studied by Western blotting,respectively.ELISA,proliferation and invasion assay were used to explore the role of CXCL12 and CXCL8 for metastatic process of colon cancer and interaction between colon cancer cell and stromal cell in the microenvironment,respectively.Results The expression of CXCL8 was detected in all colon cancer cell lines,fibroblasts and HUVEC,while CXCL12 was expressed only in DLD-1 cell and fibroblast.The secretion level of CXCL8 in CaCo-2,WiDr,HT-29 and HUVEC (2.54-fold vs.control,2.07-fold vs.control,1.87-fold vs.control,2.79-fold vs.control) was enhanced by CXCL12 that derived from fibroblasts(P ＜ 0.01).CXCL8 could significantly promote the proliferation,migration of HUVEC (P ＜0.01).CXCL8 and CXCL12 enhanced proliferation of HUVEC (P ＜ 0.01),invasion of HUVEC and HT-29 (P ＜ 0.01) in a concentration-dependent manner.Conclusion Fibroblasts derived CXCL12 enhanced the CXCL8 secretion in colon cancer cells,and CXCL8 and CXCL12 can promote the proliferation and invasion of colon cancer cells.

Effect of polyunsaturated fatty acids ω-3 and ω-6 on angiogenesis formation in human gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of polyunsaturated fatty acids (PUFA) ω-3 and ω-6, and their middle metabolites PGE2 and PGE3 on angiogenesis formation of gastric cancer, and to explore associated mechanism.</p><p><b>METHODS</b>The effects of ω-3, ω-6, PGE2, PGE3 on the proliferation and migration of human umbilical vein endothelial cell (HUVEC) were measured by proliferation and migration assay respectively. The angiogenesis assay in vivo was used to measure the effects of ω-3, ω-6, PGE2 and PGE3 on neovascularization. In all the assays, groups without ω-3, ω-6, PGE2 and PGE3 were designed as the control.</p><p><b>RESULTS</b>With the increased concentration of ω-6 from 1 μmol/L to 10 μmol/L, the proliferation ability of HUVECs enhanced, and the number of migration cells also increased from 28.2±3.0 to 32.8±2.1, which was higher than control group (21.2±3.2) respectively (both P<0.05). With the increased concentration of ω-3 from 1 μmol/L to 10 μmol/L, the proliferation ability of HUVECs was inhibited, and the number of migration cells decreased from 15.8±2.0 to 11.0±2.1, which was lower than control group (22.1±3.0) respectively (both P<0.05). In the angiogenesis assay, compared with control group (standard number: 43 721±4 654), the angiogenesis ability of HUVECs was significantly enhanced by ω-6 in concentration-dependent manner (1 μmol/L group: 63 238±4 795, 10 μmol/L group: 78 166±6 123, all P<0.01). Meanwhile, with the increased concentration of ω-3 from 1 μmol/L to 10 μmol/L, the angiogenesis ability was significantly decreased from 30 129±3 102 to 20 012±1 541(all P<0.01). The proliferation and migration ability of HUVECs were significantly promoted by ω-6 metabolites PGE2 (P<0.05) in a concentration-dependent manner. In contrast, ω-3 metabolites PGE3 significantly inhibited the proliferation and migration ability of HUVECs in a concentration-dependent manner (all P<0.05). After rofecoxib (a COX-2 specific inhibitor) inhibited the expression of COX-2, the expression level of PGE2 was significantly decreased in a dose-dependent manner. In co-culture system, whose gastric cancer cells expressed positive COX-2, ω-6 could increase angiogenesis of gastric cancer cells(P<0.01), but ω-3 could inhibit such angiogenesis(P<0.01). In co-culture system, whose gastric cancer cells did not express COX-2, ω-3 could inhibit the angiogenesis of gastric cancer cells (P<0.05), but ω-6 had no effect on angiogenesis.</p><p><b>CONCLUSIONS</b>The PUFA ω-6 can enhance the angiogenesis via the promotion of proliferation and migration of HUVECs, and COX-2 and PGE2 may play an important role in this process, whereas, the ω-3 can inhibit the angiogenesis through its middle metabolites PGE3 to inhibit the proliferation and migration of HUVECs. Results of this experiment may provide a new approach to inhibit and prevent the spread of gastric cancer.</p>

The effect of interleukin-1 receptor antagonist on metastasis through inhibiting HGF secretion in human colon cancer cell lines / 中华普通外科杂志

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.

Effect of colon cancer cell-derived IL-1α on the migration and proliferation of vascular endothelial cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Western 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.</p><p><b>RESULTS</b>Western 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).</p><p><b>CONCLUSIONS</b>Our 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.</p>