High level of urokinase-type plasminogen activator is a new prognostic marker in patients with gastric carcinoma

Relationship between matrix metalloproteinase-2 mRNA expression and clinicopathological and urokinase-type plasminogen activator system parameters and prognosis in human gastric cancer

AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric cancer.

METHODS: Expression of MMP-2 mRNA, uPA, and uPA-R mRNA in tumor tissues and ≥5 cm adjacent normal tissues from 67 cases of gastric cancer was studied using RT-PCR and Northern blot respectively. Survival analyses were done using the Kaplan-Meier method.

RESULTS: The expression rates of MMP-2 mRNA, uPA and uPA-R mRNA in tumor tissues (31%, 41%, and 51%, respectively) were significantly higher than those in ≥5 cm adjacent tissues (19%, 11%, and 9%; χ² = 4.59, 43.58, and 53.24 respectively, P<0.05, 0.0001, and 0.0001, respectively). Expression of MMP-2 mRNA was significantly correlated with lymph node metastasis (metastasis: 61.9%, no metastasis: 39.1%, χ² = 7.61, P<0.05), Lauren’s classification of diffuse/mixed types: 54.2%, intestinal type: 26.3%, χ² = 4.25, P<0.05, expression of uPA and uPA-R mRNA (uPA+: 55.1%, uPA-: 22.2% and uPA-R+: 54.9%, uPA-R-: 18.8%, χ² = 5.72 and 6.40 respectively, P<0.05). Kaplan-Meier survival analysis of MMP-2 mRNA expression did not show significant difference in all 67 cases, but revealed an association of the expression of MMP-2 mRNA, uPA, and uPA-R mRNA with worse prognosis (P = 0.0083, 0.0160, and 0.0094, respectively).

CONCLUSION: MMP-2 may play an important role in the development of invasion and metastasis of gastric cancer.

Correlation between metastatic potential and variants from colorectal tumor cell line HT-29

AIM: To evaluate the relationship between uPA, PAI-1, CEA, PI3K and metastatic potential in three colorectal tumor cell lines.

METHODS: Metastatic model in nude rats was established by variants HT-29c and HT-29d cell lines and the metastatic potential of two tumor cell variants was compared. Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) were determined using ELISA in colorectal carcinoma WiDr, HT-29 and HT-29d cell lines with different metastatic potentials. Expression of carcinoembryonic antigen (CEA) and phosphoinositide 3-kinase (PI3-Kinase) was analyzed using immunohistochemistry (IHC) in these cell lines in vitro and in vivo. CEA expression was compared using fluorescence activated cell sorter (FACS) in vitro.

RESULTS: The number of HT-29d cells arrested in liver dramatically decreased within the initial 24 h after injection. The taking rate of liver metastases in the variant HT-29d increased as compared with parental HT-29 cells (70% versus 50%) and a variant HT-29b cells (70% versus 60%), and extensive organs were synchronously involved in metastases. The uPA concentration of variant HT-29d cell line was significantly higher than that of the non-metastatic WiDr and the low metastatic HT-29 cell lines. The variant HT-29d cells produced stronger PI3-kinase expression as compared with the non-metastatic WiDr cells and the low metastatic HT-29 cells in vivo.

CONCLUSION: The selected variant HT-29d cell exhibited an enhanced metastatic potential. The level of uPA and PAI-1 is positively correlated with the metastatic capacity of tumor cells. The expression of PI3-kinase correlates with tumor development and metastasis.