Prognostic impact of tissue inhibitor of matrix metalloproteinase-1 in esophageal carcinoma

TIMP1 is an early biomarker for detection and prognosis of lung cancer

BACKGROUND

Lung cancer remains the major cause of cancer-related deaths worldwide. Early stages of lung cancer are characterized by long asymptomatic periods that are ineffectively identified with the current screening programs. This deficiency represents a lost opportunity to improve the overall survival of patients. Serum biomarkers are among the most effective strategies for cancer screening and follow up.

METHODS

Using bead-based multiplexing assays we screened plasma and tumours of the KrasG12D/+; Lkb1f/f (KL) mouse model of lung cancer for cytokines that could be used as biomarkers. We identified tissue inhibitor of metalloproteinase 1 (TIMP1) as an early biomarker and validated this finding in the plasma of lung cancer patients. We used immunohistochemistry (IHC), previously published single-cell RNA-seq and bulk RNA-seq data to assess the source and expression of TIMP1in the tumour. The prognostic value of TIMP1 was assessed using publicly available human proteomic and transcriptomic databases.

RESULTS

We found that TIMP1 is a tumour-secreted protein with high sensitivity and specificity for aggressive cancer, even at early stages in mice. We showed that TIMP1 levels in the tumour and serum correlate with tumour burden and worse survival in mice. We validated this finding using clinical samples from our institution and publicly available human proteomic and transcriptomic databases. These data support the finding that high tumour expression of TIMP1 correlates with an unfavorable prognosis in lung cancer patients.

CONCLUSION

TIMP1 is a suitable biomarker for lung cancer detection.

Evaluation of MMP-9 and MMP-2 and their suppressor TIMP-1 and TIMP-2 in adenocarcinoma of esophagogastric junction

OBJECTIVE

Adenocarcinoma of esophagogastric junction (AEG) is a lethal malignancy featured with early metastasis, poor prognosis, and few treatment options. Matrix metalloproteinase (MMP) and metalloproteinase suppressor (TIMP) have been considered to be associated with cancer invasion and metastasis. In our study, we evaluated expressions of MMP-9, MMP-2, TIMP-1, and TIMP-2 in AEG and their correlation with clinicopathological parameters and the overall survival rate.

METHODS

Expressions of MMP-9, MMP-2, TIMP-1, and TIMP-2 in specimens from 120 AEGs were detected by immunohistochemistry. The correlations between expressions of these four proteins and clinicopathological characters were analyzed by chi-square test. Moreover, the prognostic value of these four biomarkers was evaluated by univariate analysis with Kaplan-Meier method and multivariate analysis with Cox regression model.

RESULTS

The positive expression rate of MMP-9, MMP-2, TIMP-1, and TIMP-2 was 65%, 53%, 70%, and 49%, respectively, in the detected 120 AEG samples. MMP-9 was significantly associated with poorly histological differentiation (P=0.001), lymph node metastasis (P=0.007), and UICC stage (P=0.008). TIMP-1 showed significantly reversed correlations with histological differentiation (P=0.001), lymph node metastasis (P=0.007), and Union for International Cancer Control stage (P=0.008). Univariate analysis revealed that lymph node metastasis (P=0.002), depth of invasion (P=0.050), and MMP-9+/TIMP-1 phonotype (P<0.001) were significantly associated with the overall survival rate. Multivariate analyses demonstrated that MMP-9+/TIMP-1-phenotype was an independent prognostic factor in AEGs.

CONCLUSION

Detection of MMP-9 and TIMP-1 expression allows stratification of AEG patients into different survival categories and can be useful for precise individual evaluation and survival prediction.

Tissue Inhibitor of Metalloproteinase-1 Is Confined to Tumor-Associated Myofibroblasts and Is Increased With Progression in Gastric Adenocarcinoma

The tissue inhibitor of metalloproteinase-1 (TIMP-1) inhibits the extracellular matrix-degrading activity of several matrix metalloproteinases, thereby regulating cancer cell invasion and metastasis. Studies describing the expression pattern and cellular localization of TIMP-1 in gastric cancer are, however, highly discordant. We addressed these inconsistencies by performing immunohistochemistry and in situ hybridization analyses in a set of 49 gastric cancer lesions to reexamine the TIMP-1 localization. In addition, we correlated these findings to clinicopathological parameters. We show that strong expression of TIMP-1 protein and mRNA was observed in a subpopulation of stromal fibroblast-like cells at the periphery of the cancer lesions. In a few cases, a small fraction of cancer cells showed weak expression of TIMP-1 protein and mRNA. The stromal TIMP-1-expressing cells were mainly tumor-associated myofibroblasts. In the normal-appearing mucosa, scattered TIMP-1 protein was only found in chromogranin A positive cells. TIMP-1-positive myofibroblasts at the invasive front of the tumors were more frequently seen in intestinal than in diffuse histological subtype cases (p=0.009). A significant trend to a higher number of cases showing TIMP-1 staining in myofibroblasts with increasing tumor, node, metastasis (TNM) stage was also revealed (p=0.041). In conclusion, tumor-associated myofibroblasts are the main source of increased TIMP-1 expression in gastric cancer.

Antidiabetic drug metformin inhibits esophageal adenocarcinoma cell proliferation in vitro and in vivo

Esophageal carcinoma is the eighth most common cancer worldwide and the sixth leading cause of cancer-related deaths, with one of the worst prognoses of any form of cancer. Treatment with the anti-diabetic drug metformin has been associated with reduced cancer incidence in patients with type 2 diabetes. This study therefore evaluated the effects of metformin on the proliferation, in vitro and in vivo, of human esophageal adenocarcinoma cells, as well as the microRNAs associated with the antitumor effects of metformin. Metformin inhibited the proliferation of the esophageal adenocarcinoma cell lines OE19, OE33, SK-GT4 and OACM 5.1C, blocking the G0 to G1 transition in the cell cycle. This was accompanied by strong reductions in G1 cyclins, especially cyclin D1, cyclin-dependent kinase (Cdk)4, and Cdk6, and decreases in retinoblastoma protein phosphorylation. In addition, metformin reduced the phosphorylation of epidermal growth factor receptor and insulin-like growth factor and insulin-like growth factor-1 receptor, as well as angiogenesis-related proteins, such as vascular endothelial growth factor, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2. Metformin also markedly altered microRNA expression. Treatment with metformin of athymic nude mice bearing xenograft tumors reduced tumor proliferation. These findings suggest that metformin may have clinical use in the treatment of esophageal adenocarcinoma.

Serum tissue inhibitor of metalloproteinase 1 (TIMP-1) and vascular endothelial growth factor A (VEGF-A) are associated with prognosis in esophageal cancer patients

PURPOSE

The matrix metalloproteinases, tissue inhibitors of metalloproteinases and angiogenesis contribute to growth and spread of cancer. We investigated the correlation between pretreatment serum levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) and vascular endothelial growth factor A (VEGF-A), and clinicopathologic features and survival in patients with esophageal cancer (EC).

MATERIAL/METHODS

Serum TIMP-1 and VEGF-A were measured by enzyme-linked immunosorbent assay (ELISA) in 89 patients with EC, and 30 healthy controls.

RESULTS

Serum TIMP-1 and VEGF-A levels were significantly higher in patients with esophageal carcinoma than in the control group (p=0.001 and p<0.001, respectively). High levels of TIMP-1 were associated with histological type (p<0.001), tumor depth (p<0.001), stage (p<0.001) and lymph node metastases (p=0.001). Subgroup analysis showed that tumor size (p<0.001), tumor depth (p<0.001), stage (p<0.001), lymph node metastases (p=0.002), distant metastases (p=0.009) and resectability (p=0.003), were correlated with an elevated level of VEGF-A. Patients with elevated levels of TIMP-1 and VEGF-A had a significantly lower overall survival (p=0.02 and p=0.048, respectively), and disease-free survival (TIMP-1, p<0.001).

CONCLUSION

High serum levels of TIMP-1 and VEGF-A were found to be associated with tumor progression and unfavorable prognosis in patients with EC.

Maximum standardized uptake value in 18F-fluoro-2-deoxyglucose positron emission tomography is associated with advanced tumor factors in esophageal cancer

Positron emission tomography/computed tomography (PET/CT) with ¹⁸F-fluoro-2-deoxyglucose (FDG-PET/CT) has become established in cancer imaging, and derived maximum standardized uptake values (SUVmax) add functional information regarding cancer, including esophageal squamous cell carcinoma (ESCC). The aim of the present study was to determine the clinical significance and association of tumor progression using SUVmax derived from PET/CT images in patients with ESCC. In total, 101 patients with ESCC were assessed using FDG-PET/CT and the SUVmax was then compared with the clinical backgrounds and prognoses of the patients. Endoscopic ESCC biopsy specimens were obtained in order to analyze mRNA expression relative to tumor progression. The results showed that values for SUVmax were significantly higher in patients with tumor progression factors, particularly those with lymph node metastasis. Analysis of receiver operating characteristics curves revealed an optimum SUVmax cut-off value of 10.26 for node-positive disease. Patients with SUVmax ≥10.26 had gene alterations with epithelial-mesenchymal transition (EMT) and significantly worse overall survival (P=0.0012). A higher SUVmax in patients with ESCC was associated with lymph node metastasis and a poorer prognosis. Thus, the SUVmax may reflect the potential of EMT in patients with ESCC.

Levels of matrix metalloproteinase-1 and tissue inhibitors of metalloproteinase-1 in gastric cancer

AIM: To evaluate the levels of preoperative serum matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in gastric cancer.

METHODS: One hundred gastric cancer patients who underwent gastrectomy were enrolled in this study. The serum concentrations of MMP-1 and TIMP-1 in these patients and in fifty healthy controls were determined using an enzyme-linked immunosorbent assay.

RESULTS: Higher serum MMP-1 and TIMP-1 levels were observed in patients than in controls (P < 0.001). Serum MMP-1 and TIMP-1 levels were positively associated with morphological appearance, tumor size, depth of wall invasion, lymph node metastasis, liver metastasis, perineural invasion, and pathological stage. They were not significantly associated with age, gender, tumor location, or histological type.

CONCLUSION: Increased MMP-1 and TIMP-1 were associated with gastric cancer. Although these markers are not good markers for diagnosis, these markers show in advanced gastric cancer.

Lack of relationship between TIMP-1 tumour cell immunoreactivity, treatment efficacy and prognosis in patients with advanced epithelial ovarian cancer

Background

Tissue inhibitor of metalloproteinase 1 (TIMP-1) is a natural inhibitor of the matrix metalloproteinases (MMPs) which are proteolytic enzymes involved in degradation of extracellular matrix thereby favoring tumour cell invasion and metastasis. TIMP-1 activity in tumour tissue may therefore play an essential role in the progression of a malignant tumour.

The primary aim of the present study was to evaluate TIMP-1 protein immunoreactivity in tissue from primary ovarian cancer patients and associate these findings with the course of the disease including response to treatment in the individual patient.

Methods

TIMP-1 was assessed by immunohistochemistry (in tissue micro arrays) in a total of 163 ovarian cancer specimens obtained from primary debulking surgery during 1991-1994 as part of a randomized clinical protocol.

Results

Positive TIMP-1 immunoreactivity was found in 12.3% of the tumours. The median survival time for the 143 patients with TIMP-1 negative tumours was 23.7 months [19.0-29.4] 95% CI, while the median survival time for the 20 patients with TIMP-1 positive tumours was 15.9 months [12.3-27.4] 95% CI. Although a difference of 7.8 months in median overall survival in favor of the TIMP-1 tumour negative patients was found, this difference did not reach statistical significance (p = 0.28, Kaplan-Meier, log-rank test). Moreover, TIMP-1 immunoreactivity was not associated with CA125 response (p = 0.53) or response at second look surgery (p = 0.72).

Conclusion

TIMP-1 immunoreactivity in tumour tissue from patients with primary epithelial ovarian cancer did not correlate with patient survival or response to combination platinum/cyclophosphamide therapy.

Activin A Causes Cancer Cell Aggressiveness in Esophageal Squamous Cell Carcinoma Cells

BACKGROUND

Expression of activin A is associated with lymph node metastasis and clinical stage in esophageal cancer.

METHODS

To clarify the aggressive behavior of tumors with high activin A expression, we used the beta subunit of activin A to establish stable activin betaA (Act-betaA)-transfected carcinoma cells in two human esophageal carcinoma cell lines, KYSE110 and KYSE140. The biological behavior of these cells was compared with that in mock-transfected cells from the same cell lines. We focused our attention on cell growth and tumorigenesis, and proliferation and apoptosis.

RESULTS

Both Act-betaA-transfected carcinoma cell lines showed a higher growth rate than the mock-transfected carcinoma cells. In an in vitro invasion assay and a xenograft analysis, the Act-betaA-transfected carcinoma cells showed far higher proliferation in vitro and a higher potency for tumorigenesis in vivo, respectively. Moreover, in an analysis of apoptosis via Fas stimulation, the Act-betaA-transfected carcinoma cells showed a higher tolerance to apoptosis compared with the mock-transfected carcinoma cells. Moreover, anti-activin-neutralizing antibody-treated squamous cell cancer cell lines inhibited their migration.

CONCLUSIONS

Collectively, these data indicate that continuous high expression of activin A in esophageal carcinoma cells is not related to tumor suppression, but rather to tumor progression in vitro and in vivo. The inhibition of activin might be one of the methods to attenuate tumor aggressiveness.

[The role of matrix metalloproteinases and tissue inhibitors of metalloproteinases in invasion of tumours of neuroepithelial tissue]

Tumour invasion requires degradation of extracellular matrix components and migration of cells through degraded structures into surrounding tissues. Matrix metalloproteinases (MMP) constitute a family of zinc and calcium-dependent endopeptidases that play a key role in the breakdown of extracellular matrix, and in processing of cytokines, growth factors, chemokines and cell surface receptors. Their activity is regulated at the levels of transcription, activation and inhibition by tissue inhibitors of metalloproteinases (TIMP). Changes in expression of MMP and TIMP are implicated in tumour invasion, because they may contribute to both migration of tumour cells and angiogenesis. Alterations of MMP expression observed in brain tumours arouse interest in the development and evaluation of synthetic matrix metalloproteinase inhibitors as antitumour agents.

Protein levels of tissue inhibitor of metalloproteinase-1 in tumor extracts as a marker for prognosis and recurrence in patients with gastric cancer

BACKGROUND

Tissue inhibitor of metalloproteinase-1 (TIMP-1) correlates with tumor progression in patients with gastric cancer; however, the clinical significance of TIMP-1 as a marker for prognosis and recurrence has not been fully clarified.

METHODS

TIMP-1 protein was measured by an enzyme-linked immunosorbent assay in tumor samples from 86 patients who had undergone surgical resection. An intratumoral TIMP-1 value of 10.0 ng/mg protein or more was defined as positive. Patients were followed up for more than 5 years prospectively.

RESULTS

Thirty-one of the 86 patients (36.0%) were positive for TIMP-1. Kaplan-Meier curves for overall survival were significantly different between patients who were positive and those who were negative for TIMP-1. Univariate analysis of factors affecting overall survival showed that depth of tumor invasion; lymph node metastasis; peritoneal dissemination; lymphatic invasion; venous invasion; Lauren classification of histology; curability; and TIMP-1 were statistically significant. Stepwise multivariate analysis for overall survival demonstrated that depth of tumor invasion, nodal metastasis, peritoneal dissemination, and TIMP-1 remained independent prognostic factors. Kaplan-Meier curves for disease-free survival were significantly different between patients who were positive and those who were negative for TIMP-1. The incidence of recurrence was significantly higher in patients positive for TIMP-1 than in those who were negative for TIMP-1. The frequency at each site of recurrence was higher in patients positive for TIMP-1.

CONCLUSION

These results suggested that the protein concentration of TIMP-1 in the tumor extracts was a useful marker for overall survival, disease-free survival, and disease recurrence in patients with gastric cancer. Thus, tumor TIMP-1 may serve to identify a high-risk group, for whom optimal surgical and medical treatment can be given.

TIMP-3 deficiency in the host, but not in the tumor, enhances tumor growth and angiogenesis

Tumor cells, stromal cell compartment and the extracellular matrix (ECM) together generate a multifaceted tumor microenvironment. Matrix metalloproteinases and their tissue inhibitors (TIMPs) provide a means for tumor-stromal interaction during tumorigenesis. Among TIMPs, TIMP-3 is uniquely localized to the ECM and is frequently silenced in human cancers. Here, we asked whether the absence of TIMP-3 in the tumor cell or the host affects the process of tumorigenesis. Timp-3(-/-) ES-cell clones were generated and used to develop teratomas in nude mice. Timp-3(-/-) teratomas showed similar tumor take, growth, and angiogenesis compared to timp-3(+/+) teratomas. To study the effect of TIMP-3 ablation in the host stroma, we measured the growth kinetics of subcutaneous B16F10 melanomas in timp-3(-/-) and wild-type littermates. Tumors grew significantly faster in timp-3(-/-) than in wild-type mice and their CD31 content was significantly higher indicating increased angiogenesis. Augmented angiogenesis in timp-3(-/-) mice was directly tested using Matrigel plug and Gelfoam assays. In response to FGF-2, timp-3(-/-) endothelial cells invaded more efficiently, leading to enhanced formation of functional blood vessels. Thus, TIMP-3 deficiency in the host, but not in the tumor per se, leads to enhanced tumor growth and angiogenesis. TIMP-3 located within the tumor microenvironment inhibits tumorigenesis.

Gene-expression profile changes correlated with tumor progression and lymph node metastasis in esophageal cancer

PURPOSE

The purpose of this research was to identify molecular clues to tumor progression and lymph node metastasis in esophageal cancer and to test their value as predictive markers.

EXPERIMENTAL DESIGN

We explored the gene expression profiles in cDNA array data of a 36-tissue training set of esophageal squamous cell carcinoma (ESCC) by using generalized linear model-based regression analysis and a feature subset selection algorithm. By applying the identified optimal feature sets (predictive gene sets), we trained and developed ensemble classifiers consisting of multiple probabilistic neural networks combined with AdaBoosting to predict tumor stages and lymph node metastasis. We validated the classifier abilities with 18 independent cases of ESCC.

RESULTS

We identified 71 genes of 1289 cancer-related genes of which the expression correlated with tumor stages. Of the 71 genes, 47 significantly differed between the Tumor-Node-Metastasis pT1/2 and pT3/4 stages. Cell cycle regulators and transcriptional factors possibly promoting the growth of tumor cells were highly expressed in the early stages of ESCC, whereas adhesion molecules and extracellular matrix-related molecules possibly promoting invasiveness increased in the later stages. For lymph node metastasis, we identified 44 genes with predictive values, which included cell adhesion molecules and cell membrane receptors showing higher expression in node-positive cases and cell cycle regulators and intracellular signaling molecules showing higher expression in node-negative cases. The ensemble classifiers trained with the selected features predicted tumor stage and lymph node metastasis in the 18 validation cases with respective accuracies of 94.4% and 88.9%. This demonstrated the reproducibility and predictive value of the identified features.

CONCLUSION

We suggest that these characteristic genes will provide useful information for understanding the malignant nature of ESCC as well as information useful for personalizing the treatments.

An immunohistochemical study of TIMP-3 expression in oesophageal squamous cell carcinoma

Tissue inhibitor of metalloproteinase-3 (TIMP-3) inhibits the activity of matrix metalloproteinase, which may play an important role in carcinoma invasion and metastasis. We have investigated the relationship between TIMP-3 reduction and clinicopathological factors in oesophageal squamous cell carcinoma (ESCC). We examined tissue specimens that had been removed from 90 patients with thoracic oesophageal cancer who had undergone surgery between 1983 and 2001. Immunohistochemical staining was performed by the standard streptavidin–biotin method. Immunostaining of TIMP-3 was seen in the cytoplasm of cancer cells and normal oesophageal epithelial cells, particularly in cells located in shallow areas of the tumour. TIMP-3 preserved (+), moderate (±), and reduced (−) cases accounted for 30, 27, and 33 of the 90 patients, respectively (33, 30, 37%). Significant correlations were observed between TIMP-3 expression and depth of tumour invasion (P=0.001), number of lymph node metastases (P=0.003), infiltrative growth pattern (P=0.003), and disease stage (P=0.005). The survival rates of patients with TIMP-3 (−) cancer were significantly lower than those of patients with TIMP-3 (+) and TIMP-3 (±) cancer (P=0.0003). The mean 5-year survival rates of patients with TIMP-3 (+), (±), and (−) were 50, 58, and 21%, respectively. In conclusion, decreased expression of TIMP-3 protein correlates with invasive activity and metastasis. This makes the prognosis for patients with cancer that has lost TIMP-3 significantly less favourable than that for patients with cancer that has maintained TIMP-3.

N-Cadherin Is Regulated by Activin A and Associated with Tumor Aggressiveness in Esophageal Carcinoma

PURPOSE

Activin A is a member of the transforming growth factor beta superfamily and plays an important role in the differentiation of embryonic stem cells. We have reported previously that the expression of activin A is associated with lymph node metastasis in esophageal cancer, and our purpose in the current work is to clarify the molecular mechanism of the aggressive behavior of tumors that have high activin A expression.

EXPERIMENTAL DESIGN

We have compared the gene expression profiles of human esophageal carcinoma cell lines that were stably transfected with activin beta A, which is a subunit of activin A, with those of control human esophageal carcinoma cell lines, using a cDNA microarray.

RESULTS

We found that the expression level of neuronal cadherin (N-cadherin) was higher in the transfectants than in the control cells. N-cadherin was located on the cell surface of the transfectants, irrespective of the expression of epithelial cadherin (E-cadherin), and the expression of N-cadherin mRNA was significantly associated with that of activin beta A mRNA in clinical samples of esophageal carcinoma (n = 51; r = 0.855). A clinicopathologic analysis suggested that expression of N-cadherin mRNA was associated with the depth of tumor wall invasion, and a group of patients with high expression of N-cadherin mRNA showed a significantly poorer prognosis than a group of patients with low N-cadherin expression (P = 0.046).

CONCLUSIONS

These results indicate that activin A might mediate the expression of N-cadherin and that this may be associated with depth of invasion and poor prognosis.

The favorable prognostic impact of tissue inhibitor of matrix metalloproteinases-1 protein overexpression in breast cancer cells

The tissue inhibitor of metalloproteinases-1 (TIMP1) inhibits tumor cell invasion and metastasis in experimental models; in addition, TIMP1 is supposed to possess another important function, cell growth promotion. The potential prognostic significance of TIMP1 in breast cancer remains unclear. We evaluated the significance of the immunohistochemical expression of TIMP1 in a well-documented series of 133 infiltrating breast carcinomas by examining any possible statistical association between this expression and numerous clinicopathological parameters as well as patients' disease-free interval. TIMP1 was generally expressed in both stromal and cancer cells in our specimens. TIMP1 was overexpressed in cancer cells of 60.15% of all cases. Tumors of high histological and nuclear grade were found to overexpress TIMP1 less frequently than the rest (p=0.003 and p=0.057, respectively). Interestingly, TIMP1 overexpression was inversely associated with cell proliferation, the latter being evidenced by Ki67 immunoreactivity (p=0.028). TIMP1 immunostaining was in parallel with metalloproteinase-2 (MMP2) immunoexpression in both cancer and stromal cells. Multivariate analysis disclosed that TIMP1 overexpression in cancer cells was an independent determining factor for prognosis (p=0.006); TIMP1 overexpression in malignant cells appeared to correlate with favorable outcome, particularly in patients with lack of nodal metastases and in patients with MMP2-negative immunophenotype (p=0.0252). The upregulation of TIMP1 cancer cell expression in breast cancer may suggest that this marker has a multifunctional role apart from that of metalloproteinase inhibitor since it was found to be related to malignant cells' differentiation and proliferation. TIMP1 overexpression in cancer cells appears for the first time to be a promising indicator of favorable prognosis in breast cancer.

Platelet-derived endothelial cell growth factor mediates Rho-associated coiled-coil domain kinase messenger RNA expression and promotes cell motility

BACKGROUND

Platelet-derived endothelial cell growth factor (PD-ECGF), whose expression is increased in several cancers, is an endothelial cell mitogen and has chemotactic activity in vitro and angiogenic activity in vivo. Tumors with high PD-ECGF expression tend to have frequent lymph node metastasis and are associated with poor outcome.

METHODS

We screened genes transduced by PD-ECGF transfection to the colon cancer cell line DLD-1 by using a complementary DNA microarray. Cell motility was evaluated by in vitro migration assay. Actin fiber polymerization was visualized by immunofluorescent detection of phalloidin.

RESULTS

Rho-associated coiled-coil domain kinase (ROCK1) was found to be significantly overexpressed in PD-ECGF transfectants compared with mock cells. PD-ECGF transfectants showed higher cell motility than mock cells. The parental cell, DLD-1, with recombinant PD-ECGF showed higher cell motility than that without recombinant PD-ECGF, in which motility was blocked by the neutralizing antibody of PD-ECGF or Y-27632, a specific inhibitor of ROCK1. Moreover, the actin fiber polymerization, which is a marker of activation of ROCK1, was higher in PD-ECGF transfectants than in mock cells.

CONCLUSIONS

PD-ECGF expression may be associated with cancer cell migration via activation of ROCK1. This may explain one mechanism by which tumors with high expression of PD-ECGF show aggressive behavior.