Higher CO_2-insufflation pressure inhibits the expression of adhesion molecules and the invasion potential of colon cancer cells

AIM： To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS： With an/n vitro artificial pneumoperitoneum model, SW1116 human colon carcinoma cells were exposed to CO2-insufflation in 5 different pressure groups： 6 mmHg, 9 mmHg, 12 mmHg, 15 mmHg and control group, respectively for 1 h. Expression of E-cadherin, ICAM-I, CD44 and E-selectin was meas- ured at 0, 12, 24, 48 and 72 h after CO2-insufflation using flow cytometry. The adhesion and invasion capacity of SW1116 cells before and after exposure to CO2-insufflation was detected by cell adhesion/invasion assay in vitro. Each group of cells was injected intraperitoneally into 16 BALB/C mice. The number of visible abdominal cavity tumor nodules, visceral metas-tases and survival of the mice were recorded in each group. RESULTS： The expression of E-cadherin, ICAM-1, CD44 and E-selectin in SWl116 cells were changed significantly following exposure to CO2 insufflation at different pressures （P 〈 0.05）. The expression of E-cadherin, CD44 and ICAM-1 decreased with increasing CO2-insufflation pressure. The adhesive/ invasive cells also decreased gradually with increasing pressure as determined by the adhesion/invasion assay. In animal experiments, the number of abdominal cavity tumor nodules in the 15 mmHg group was also significantly lower than that in the 6 mmHg group （29.7± 9.91 vs 41.7±14.90, P = 0.046）. However, the survival in each group was not statistically different. CONCLUSION： CO2-insufflation induced a temporary change in the adhesion and invasion capacity of cancer cells in vitro. Higher CO2-insufflation pressure inhibited adhesion, invasion and metastatic potential in vitro and in vivo, which was associated with reduced expression of adhesion molecules.

Expression of γ-synuclein in colorectal cancer tissues and its role on colorectal cancer cell line HCT116

AIM: To investigate the expression pattern of γ-synuclein in colorectal cancer (CRC) tissues, and to study the effects of γ-synuclein on CRC cell line HCT116 biological features in vitro.METHODS: The expression pattern of γ-synuclein was determined in 54 CRC tissues and 30 tumor-matched nonneoplastic adjacent tissues (NNAT) 5 cm away from the tumor via real-time quantitative reverse transcription PCR (RT-PCR) and immunohistochemistry. The relationship between γ-synuclein protein expression and clinicopathological factors of CRC tissues was analyzed. Three small interfering RNA (siRNA) targeting γ-synuclein mRNA plasmids were constructed and transfected into the CRC cell line HCT116. The stable cell lines were selected with G-418 for 28 d, and the biological features of these cells were examined by cell growth curve, soft agar assay, and cell migration and invasion assays in vitro. RESULTS: The expression of γ-synuclein mRNA and protein was much higher in CRC tissue samples than in NNAT samples (P = 0.02, P = 0.036). There was a significant correlation between the γ-synuclein protein expression and clinical stage and lymph node involvement of CRC (P = 0.02, P = 0.033). In functional analysis we found that down-regulation of γ-synuclein expression in HCT116 cells could inhibit the growth, colony formation rate, and migration and invasion ability of HCT116 cells.CONCLUSION: Increased expression of γ-synuclein in CRC tissues and the biological effects of reduced γ-synuclein expression on HCT116 cells suggest that γ-synuclein may play a positive role in the progression of CRC.

Circulating osteopontin per tumor volume as a prognostic biomarker for resectable intrahepatic cholangiocarcinoma

Background:The role of osteopontin(OPN)in intrahepatic cholangiocarcinoma(ICC)remains controversial.This study aimed to explore the prognostic value of OPN in patients with ICC undergoing curative resection.Methods:Patients undergoing curative resection from 2005 to 2016 were identified for inclusion in this retrospective study.The expression level of OPN in tumors was measured in each of the 228 patients by immunohistochemistry.Circulating OPN in serum was tested in 124 patients by ELISA.Tumor volume was calculated according to preoperative imaging or operation record.Proliferation assay,wound healing assay,and invasion assay were performed to investigate the biological function.Results:Low expression of OPN in tissue was associated with lymph node metastasis(P=0.009)and shorter overall survival(OS)(P=0.001).A low level of circulating OPN/volume was associated with multiple tumors(P<0.001),vascular invasion(P=0.027),visceral peritoneal perforation(P=0.001),and lymph node metastasis(P=0.002).It was also able to predict the invasive behavior,lymph node metastasis,and early recurrence with the area under the receiver operating curve(AUC)of being 0.719,0.708 and 0.622 respectively.Patients with a low level of circulating OPN/volume had shorter OS(P=0.028)and disease-free survival(DFS)(P=0.004)and could benefit from adjuvant chemotherapy(P=0.011).Compared with negative controlled cells,ICC cell lines,which expressed more OPN,showed a decelerated proliferation rate,the weaker ability of migration and invasion,while the opposite was true for the cells expressed less OPN.MMP1,MMP10,and CXCR4 were negatively regulated by OPN.Conclusions:A low level of circulating OPN/volume could indicate aggressive characteristics,along with poor prognosis and efficacy of adjuvant chemotherapy in ICC patients.Over expression of OPN may inhibit phenotypes facilitating ICC metastasis by negatively regulating MMP1,MMP10,and CXCR4.