Urokinase receptor and vascular endothelial growth factor are synergistically associated with the liver metastasis of colorectal cancer

The Soluble Urokinase-Type Plasminogen Activator Receptor as a Biomarker for Survival and Early Treatment Effect in Metastatic Colorectal Cancer

The soluble urokinase-type plasminogen activator receptor (suPAR) is prognostic for overall survival (OS) in colorectal cancer (CRC). Our study explored the association between baseline suPAR and OS and progression-free survival (PFS) in metastatic CRC (mCRC). It is also the first study to explore the association between the initial change in suPAR level and OS, PFS and the first CT response evaluation. The study included 132 patients with mCRC treated with chemotherapy (FOLFIRI) with or without an EGFR-inhibitor. Blood samples were drawn before the first treatment cycle and in between the first and second treatment cycle. suPAR levels were determined using an ELISA assay. Using the Kaplan-Meyer method, we demonstrated a significantly shorter OS for patients with suPAR levels above the median (HR = 1.79, 95%CI = 1.10-2.92, p = 0.01). We also showed association between plasma suPAR level, gender and performance status (PS). However, we could not show any association with PFS, and analysis on the change in suPAR level provided no significant results. The results showing association between baseline suPAR and OS are in line with previous findings.

Prognostic Value of ACVRL1 Expression in Metastatic Colorectal Cancer Patients Receiving First-line Chemotherapy With Bevacizumab: Results From the Triplet Plus Bevacizumab (TRIBE) Study

BACKGROUND

No biomarkers exist to predict benefit from antiangiogenic therapy in metastatic colorectal cancer patients. ACVRL1 (activin receptor like-protein 1) encodes for ALK1, a member of the transforming growth factor-β receptor family, which directs pathologic angiogenesis. We examined the intratumoral expression of ACVRL1 and other angiogenesis pathway-related genes to identify molecular markers in the TRIBE study.

MATERIALS AND METHODS

Of 503 randomized patients, 228 had sufficient tissue for analysis. Formalin-fixed paraffin-embedded specimens were examined for expression of VEGF-A, VEGF-B, VEGF-C, VEGFR1, VEGFR2, ACVRL1, EphB4, and EGFL7 using reverse transcription polymerase chain reaction. A maximal χ² approach was used to determine the messenger RNA levels associated with progression-free survival (PFS), overall survival (OS), response rate, early tumor shrinkage, and depth of response. Recursive partitioning trees were constructed to identify composite prognostic biomarker profiles. External validation was conducted in silico using the Oncomine database.

RESULTS

High ACVRL1 expression was associated with superior OS in both treatment arms (FOLFOXIRI [5-fluorouracil, leucovorin, oxaliplatin, irinotecan]-bevacizumab, 32.7 vs. 13.5 months, hazard ratio [HR], 0.38, P = .023; FOLFIRI [5-fluorouracil, leucovorin, irinotecan]-bevacizumab, 35.1 vs. 22.0 months, HR, 0.36, P = .006) and prolonged PFS (11.7 vs. 5.9 months, multivariate HR, 0.17; P = .001) for patients receiving FOLFOXIRI-bevacizumab on univariate and multivariate analyses. In recursive partitioning analysis, ACVRL1 was the strongest discriminator of the response rate, PFS, and OS in patients receiving FOLFOXIRI-bevacizumab and of OS in patients receiving FOLFIRI-bevacizumab. In silico validation revealed significant associations between ACVRL1 expression, disease recurrence, and 1-year survival (P < .05) among all colorectal cancer stages.

CONCLUSION

ACVRL1 expression could serve as a prognostic biomarker in metastatic colorectal cancer patients receiving chemotherapy and bevacizumab and warrants further evaluation in prospective studies.

KISS1 tumor suppressor restricts angiogenesis of breast cancer brain metastases and sensitizes them to oncolytic virotherapy in vitro

KISS1 tumor suppressor protein regulates cancer cell invasion via MMP9 metalloproteinase. Downregulation of KISS1 gene expression promotes progression of breast cancer and melanoma, resulting in the development of distant metastases. In the current study, we investigated whether restoration of KISS1 expression in KISS1-deficient human metastatic breast cancer cells holds potential as an advanced anticancer strategy. To this end we engineered an infectivity-enhanced conditionally-replicative human adenovirus type 5 encoding KISS1 as an "arming" transgene in the Ad5 E3 region for an ectopic KISS1 expression in transduced cancer cells. The oncolytic potential of the vector was examined using brain-invading metastatic clones of CN34 and MDA-MB-231 breast cancer cells, which supported high levels of AdKISS1 replication, correlating with a robust CRAd-mediated cytotoxicity. Secretion of cellular factors responsible for tumor angiogenesis, cell-to-cell communication and anti-tumoral immune responses upon KISS1 expression in breast cancer cells was analyzed by a RayBiotech Kiloplex Quantibody array. Overall, our results indicate that KISS1 transgene expression provides an important benefit for CRAd-mediated cytotoxicity in breast cancer cells and holds potential as an anticancer treatment in conjunction with oncolytic virotherapy of breast and other metastatic cancers.

Intact and cleaved plasma soluble urokinase receptor in patients with metastatic colorectal cancer treated with oxaliplatin with or without cetuximab

Circulating forms of the urokinase plasminogen activator receptor (uPAR) are associated with prognosis in patients with colorectal cancer. Preclinical studies have shown that uPAR can influence the state of phosphorylation and signalling activity of the epidermal growth factor receptor (EGFR) in a ligand-independent manner. The purpose of the study was to evaluate whether plasma soluble intact and cleaved uPAR(I-III)+(II-III) levels could identify a subpopulation of patients with metastatic colorectal cancer (mCRC) where treatment with cetuximab would have a beneficial effect. Plasma samples were available from 453 patients treated in the NORDIC VII study. Patients were randomized between FLOX and FLOX + cetuximab. The levels of uPAR(I-III)+(II-III) were determined by time-resolved fluorescence immunoassay. We demonstrated that higher baseline plasma uPAR(I-III)+(II-III) levels were significantly associated with shorter progression-free survival (PFS) (HR = 1.30, 1.14-1.48, p = 0.0001) and overall survival (OS) (HR = 1.75, 1.52-2.02, p < 0.0001). Multivariate Cox analysis showed that plasma uPAR(I-III)+(II-III) was an independent biomarker of short OS (HR = 1.45, 1.20-1.75, p = 0.0001). There were no significant interactions between plasma uPAR(I-III)+(II-III) levels, KRAS mutational status and treatment either PFS (p = 0.43) or OS (p = 0.095). However, further explorative analyses indicated that patients with low levels of circulating suPAR and a KRAS wild-type tumor have improved effect from treatment with FLOX + cetuximab as compared to patients with KRAS wild-type and high levels of suPAR. These results thus support the preclinical findings and should be further tested in an independent clinical data set.

Involvement of urokinase-type plasminogen activator system in cancer: an overview

Currently, there are several studies supporting the role of urokinase-type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI-1 and PAI-2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer-targeted therapies.

High concentration of urokinase-type plasminogen activator receptor in the serum of women with primary breast cancer

Aim of the study

The purpose of this study was to assess the concentration of urokinase-type plasminogen activator receptor (uPAR) in the serum of 103 women with breast cancer. Commonly recognized prognostic factors were taken into account, including age, histological grade of malignancy, stage of clinical advancement of the disease, status of local axillary lymph nodes and the size of the primary tumour.

Material and methods

The concentration of uPAR was assessed using an enzyme-linked immunosorbent assay (R&D Systems).

Results

The concentration of uPAR in women with breast cancer was found to be higher than in a control group and the difference was statistically significant. The concentration of uPAR was found to increase in line with increasing disease stage and this too was of statistical significance. Raised levels of uPAR were found in women with breast cancer both with and without metastases to the lymph nodes of the axilla. A positive relationship was also found between the concentration of the tested receptor and the size of the primary tumour. No significant relationship, however, was found between the concentration of uPAR and the histological grade of malignancy of the tumour. No statistically significant results were obtained regarding the menopausal status of the women, that is, whether they were pre- or post-menopausal.

Conclusions

Concentration of uPAR in serum of women with breast cancer is positively correlated with the stage of advancement of the disease. Thus, the assessment of this parameter can be useful in the clinical evaluation of women with breast cancer.

Hypoxia-related proteins in patients with rectal cancer undergoing neoadjuvant combined modality therapy

BACKGROUND

We have previously demonstrated the prognostic significance of rectal cancer pathologic response to neoadjuvant chemoradiation. Recent studies in other cancers have reported that hypoxia influences response to neoadjuvant chemoradiation.

OBJECTIVE

This study aimed to 1) characterize hypoxia-related protein expression in locally advanced rectal cancer before neoadjuvant chemoradiation, 2) determine the comodulation of hypoxia-related protein expression, and 3) evaluate the relationship between hypoxia-related protein expression and overall survival, time to recurrence, and tumor regression grade.

DESIGN

Immunohistochemical analysis of 4 hypoxia-related proteins (HIF-1α, CA-IX, VEGF, and GLUT-1) was performed on archival pretreatment rectal cancer biopsies.

PATIENTS

: Eighty-five patients with locally advanced rectal cancer treated with neoadjuvant radiation and 5-fluorouracil-based chemotherapy were included.

MAIN OUTCOME MEASURES

The impact of hypoxia-related protein expression on outcome was evaluated by use of Cox proportional hazards model. Hypoxia-related protein expression was correlated with tumor regression grade by use of Spearman correlation coefficients.

RESULTS

Median follow-up was 54 months. CA-IX expression was associated with overall survival (p = 0.01). HIF-1α expression was weakly correlated with VEGF (r = 0.26, p = 0.02) and GLUT-1 (r = 0.35, p = 0.001). Hypoxia-related protein expression was not associated with time to recurrence or Mandard tumor regression grade.

CONCLUSIONS

Elevated CA-IX expression may be associated with poorer overall survival in locally advanced rectal cancer treated by neoadjuvant chemoradiation and resection. The expression of the hypoxia-related proteins HIF-1α, VEGF, and GLUT-1 may be comodulated in locally advanced rectal cancer. Further studies are needed to evaluate the mechanisms governing hypoxia regulation and the role of hypoxia in rectal cancer response to neoadjuvant chemoradiation.

A New Assay for Measurement of the Liberated Domain I of the Urokinase Receptor in Plasma Improves the Prediction of Survival in Colorectal Cancer

BACKGROUND

The liberated domain I of the urokinase plasminogen activator receptor [uPAR(I)] is a significant prognostic marker in lung and ovarian cancer, although the uPAR(I) concentration is below the limit of quantification (LOQ) in a substantial proportion of patient samples (Lung Cancer 2005;48:349–55; Clin Cancer Res 2008;14:5785–93; APMIS 2009;117:755–61). This study was undertaken to design an immunoassay with improved functional sensitivity for measuring uPAR(I) and to evaluate the prognostic value of uPAR(I) for colorectal cancer (CRC) patients.

METHODS

Surface plasmon resonance analysis identified 2 monoclonal antibodies, R3 and R20, that simultaneously bind to the liberated uPAR(I) but not to intact uPAR. We used R3 for capture and Eu-labeled R20 for detection in designing a 2-site sandwich time-resolved fluorescence immunoassay (TR-FIA 4) for measuring liberated uPAR(I). TR-FIA 4 was validated for use with citrated plasma. The prognostic value of the uPAR(I) concentration was evaluated in 298 CRC patients. The Cox proportional hazards model was used for the uni- and multivariate survival analyses.

RESULTS

The LOQ was 0.65 pmol/L. Liberated uPAR(I) was measurable in all patient samples with TR-FIA 4. In the multivariate analysis that included sex, age, tumor stage, tumor localization, and adjuvant treatment, the uPAR(I) concentration measured with TR-FIA 4 (hazard ratio, 1.72; 95% CI, 1.15–2.57; P = 0.009), as well as the concentration of intact soluble uPAR plus the cleaved uPAR fragment containing domains II and III, tumor stage, and age were independent predictors of prognosis.

CONCLUSIONS

TR-FIA 4 has a functional sensitivity improved 4-fold over that of the previous uPAR(I) assay. The uPAR(I) concentration measured with TR-FIA 4 is an independent predictor of prognosis in CRC patients.

Prognostic value of intact and cleaved forms of the urokinase plasminogen activator receptor in a retrospective study of 518 colorectal cancer patients

BACKGROUND

The levels of the soluble urokinase plasminogen activator receptor (suPAR) in blood have been shown to correlate with prognosis in various cancers. Plasma levels of the combined suPAR forms have previously shown to be a strong prognostic marker in the present cohort of CRC patients and could potentially identify high-risk patients among those with early stage disease. In order to investigate whether the individual suPAR forms are stronger prognostic markers than the combined amount we measured the different uPAR forms in serum from the same cohort and evaluated their prognostic significance.

MATERIAL AND METHODS

The different suPAR forms were measured in serum preoperatively collected from 518 patients. Patients were followed up to nine years (median 7.9 years) and the primary endpoint was overall survival. The different suPAR forms were measured using Time Resolved Fluorescence Immunoassays(TR-FIAs): Intact, suPAR(I-III) by TR-FIA 1; intact and cleaved, suPAR(I-III)+(II-III) by TR-FIA 2; and liberated uPAR(I) by TR-FIA 3.

RESULTS

All three uPAR variants demonstrated prognostic significance when evaluated individually. In a multivariable analysis suPAR(I-III)+(II-III) and the liberated uPAR(I) were shown to be independent markers of prognosis (HR=1.74, CI:1.33-2.26; p <0.0001 and HR=1.32; CI:1.02-1.71; p=0.036 respectively), and independent of the clinical baseline variables: age, gender, tumor stage and localization.

CONCLUSION

This study demonstrated that suPAR(I-III)+(II-III) and the liberated uPAR(I) in serum are independent prognostic markers in CRC.

Urokinase-type plasminogen activator is a marker of aggressive phenotype and an independent prognostic factor in mismatch repair-proficient colorectal cancer

The aim of this study was to determine the prognostic significance of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in colorectal cancer stratified by mismatch repair status and to determine their contribution to the aggressive phenotype predicted by loss of E-cadherin and apoptosis protease activating factor-1 (APAF-1). Immunohistochemistry for uPA and uPAR was performed on a tissue microarray comprising 811 mismatch repair-proficient and 164 mismatch repair-deficient colorectal cancers. Immunoreactivity was scored semiquantitatively and the interobserver agreement between multiple pathologists was determined. Optimal cutoff scores for uPA and uPAR positivity were obtained by receiver operating characteristic curve analysis. Agreement between pathologists was excellent for uPA and uPAR. Cutoff scores of 60% for uPA and 75% for uPAR were validated by resampling of the data. In mismatch repair-proficient colorectal cancer, overexpression of uPA and uPAR was associated with advanced pT stage (P = .009, both), an infiltrating margin (P = .009 and P = .033, respectively), and poor prognosis (P = .002 and P < .001, respectively). uPA, but not uPAR, maintained its significant prognostic effect in multivariable analysis (P = .037). In addition to loss of APAF-1 (P = .002) and E-cadherin (P < .001), uPA independently predicted an infiltrating margin (P = .016). Our findings suggest that uPA, but not uPAR, is an independent prognostic factor and that this negative effect on survival is relevant specifically for mismatch repair-proficient colorectal cancers. Moreover, the combination of uPA with E-cadherin and APAF-1 is linked to an aggressive tumor phenotype and highly predictive of an infiltrating growth pattern.

Intact and cleaved forms of the urokinase receptor enhance discrimination of cancer from non-malignant conditions in patients presenting with symptoms related to colorectal cancer

Background:

Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality in developed countries. It is known that early detection results in improved survival, and consequently there is a need for improved diagnostic tools in CRC. The plasma level of soluble urokinase plasminogen activator receptor (suPAR) was proposed as a marker in CRC patients. This study was undertaken to evaluate the individual molecular forms of suPAR as discriminators in a group of patients undergoing endoscopical examination following symptoms related to colorectal cancer.

Methods:

In a case–control study comprising 308 patients undergoing endoscopical examination following CRC-related symptoms, 77 CRC patients with adenocarcinoma were age and gender matched to: 77 patients with adenomas; 77 with other non-malignant findings, and 77 with no findings. The different uPAR forms were measured in citrate plasma collected before endoscopical examination, using three different Time Resolved – Fluorescence Immuno Assays (TR-FIA's).

Results:

All soluble uPAR forms were found to be significantly higher in cancer patients than in patients presenting with other non-malignant findings; uPAR(I) P=0.0006, suPAR(I–III) P<0.0001 and suPAR(I–III)+(II–III) P<0.0001, whereas no significant difference was found when performing similar comparisons for patients presenting with adenomas. The odds ratio (OR) for the comparison of uPAR(I) in patients with CRC to subjects with other non-malignant findings was 3.44 (95% CI:1.86–6.37). CRC patients had a mean elevated level of 20.9% (95% CI:10.2–32.6) for suPAR(I–III) and 18.5% (95% CI:9.0–28.8) for suPAR(I–III)+(II–III) compared with subjects with non-malignant findings.

Conclusions:

The findings confirm reports on increased uPAR expression in cancer patients and in particular elevated levels of suPAR in blood from CRC patients and indicate that suPAR levels in blood are increasing during carcinogenesis. Although none of the measured uPAR forms were cancer specific, our findings suggest that uPAR expression could be useful in the early detection of CRC when combined with other markers and clinical variables.

Involvement of cyclooxygenase-2 and vascular endothelial growth factor in vascularization and lymph node metastasis of colorectal cancers with submucosal invasion

BACKGROUND AND AIMS

Although patients with early colorectal cancer invading the submucosa (CRC-sm) may be treated with endoscopic mucosal resection alone, they generally undergo additional surgery because of the risk of lymph node metastasis. The aims of the present study were to examine the roles of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in tumor vascularization and to investigate whether COX-2 and VEGF expression and tumor vascularity are useful markers for predicting lymph node metastasis in CRC-sm.

METHODS

Twenty-seven resected specimens of CRC-sm with lymph node dissection were examined, and expression of COX-2 and VEGF was evaluated immunohistochemically and scored. Microvessel density (MVD) in CRC-sm tissues was estimated using a Macscope system after CD34 immunostaining. The relationships among clinicopathological parameters, COX-2 and VEGF expression, and MVD in CRC-sm tissues were then analyzed.

RESULTS

Scores for COX-2, VEGF and MVD were all significantly higher in patients with CRC-sm with lymphatic invasion or lymph node metastasis. COX-2 score (P < 0.0001) and VEGF score (P = 0.035) were significantly correlated with MVD in CRC-sm tissues. In addition, COX-2 score was significantly correlated with VEGF score in the CRC-sm specimens examined.

CONCLUSIONS

Both COX-2 and VEGF are involved in tumor vascularization in CRC-sm. COX-2 expression, VEGF expression, and MVD are possible markers for predicting lymph node metastasis in patients with CRC-sm, and use of COX-2 expression may be clinically practical.

Correlations of epidermal growth factor-mediated nuclear factor-kappa B and matrix proteinase activity with invasions of cholangiocarcinoma cells

AIM: To explore the mechanism of epidermal growth factor (EGF) in the promotion of human cholangiocarcinoma cell invasion.

METHODS: Invasion assay and cell proliferation assay were performed in human cholangiocarcinoma cell line HuCCT1 treated with different concentrations of EGF. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of matrix metalloproteinases (MMPs), urokinase type plasminogen activator (uPA) and plasminogen activator inhibitor (PAI-1) in HuCCT1 cells. The activity of nuclear factor-kappa B (NF-κB) was determined by electrophoretic mobility shift assay (EMSA). After pretreatment with pyrrolidine dithiocarbamate or ibuprofen, the invasion of HuCCT1 cells was observed.

RESULTS: EGF treatment resulted in increased invasions of HuCCT1 cells in a dose-dependent manner (cell number as EGF at 10, 100 μg/L vs 0 μg/L: 35.4 ± 6.2, 57.2 ± 7.6 vs 16.3 ± 3.1; t = 4.77, P = 0.009; t = 8.63, P = 0.001, respectively). However, EGF did not affect the proliferation in HuCCT1 cells. RT-PCR and Western blot showed that EGF dramatically increased the expression of MMP-9, uPA and PAI-1 mRNA and protein in HuCCT1 cells, but it did not change the expression of MMP-2. The activity of NF-κB was significantly increased after EGF treatment, while EGF-induced invasion of HuCCT1 cells was markedly inhibited by pretreatment with PDTC or ibuprofen (cell number: 46.6 ± 4.6 vs 62.3 ± 5.2, t = 3.168, P = 0.037; 35.3 ± 5.4 vs62.3 ± 5.2, t = 6.30, P = 0.003).

CONCLUSION: EGF promotes the invasion of human cholangiocarcinoma cells, and the up-regulation of MMP-9, uPA , PAI-1 and NF-κB activity is involved in this process.

Molecular mechanisms of hepatic metastasis in colorectal cancer

BACKGROUND

Colorectal cancer currently accounts for 11% of all cancers in the United States and is the second leading cause of cancer-related death, with the majority of deaths attributable to hepatic metastases. Many new studies are elucidating the complex molecular factors involved in this event, which could be used to generate clinically applicable screening and therapeutic tools.

METHODS

An initial Pubmed and Medline literature search using keywords such as, molecular factor, colorectal cancer, hepatic metastasis/es, and main headings, such as angiogenesis, was reviewed. Since there are many molecular factors involved in this process not all could be included in this review. The list of discussed gene products was limited to the most studied factors, identified by the number of references in the literature search, and additional recently discovered gene products with in-vivo evidence of strong metastasis association.

RESULTS

Twenty molecular factors were identified and included in the discussion of this review article. The molecular factors were separated into four groups based on their function, they are: proteolysis, adhesion, angiogenesis, and cell survival. All factors have a promising role as a screening or therapeutic target.

CONCLUSION

This review has identified the many recent advances in elucidating the pathways involved in colorectal cancer hepatic metastasis. By better understanding the many complex molecular events involved in metastasis, novel screening and therapeutic tools may be developed with the ultimate goal of preventing metastasis and increasing patient survival.

Association of interleukin-8 and plasminogen activator system in the progression of colorectal cancer

The aim of this study was to investigate the relationship of Interleukin-8 (IL-8) with vascular endothelial growth factor (VEGF) and plasminogen activator system (PA system) in the progression of colorectal cancer (CRC). In eighty-seven patients with CRC, the levels of IL-8, and VEGF as representative angiogenic factors and urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1), and PAI-2 as representative invasive factors were quantitatively assayed in tumor and adjacent normal tissues. The levels of IL-8, VEGF, and PA system factors in tumor tissues were all significantly higher than those in normal tissues. The IL-8 level was significantly associated with tumor size, depth of infiltration, Dukes stage, and liver metastasis, and also significantly correlated with the levels of VEGF, uPAR, uPA, and PAI-1. The VEGF level was significantly associated with tumor size, vascular involvement. The levels of uPAR and PAI-1 were significantly associated with tumor size and depth of infiltration, and the uPAR level was associated with liver metastasis. The VEGF level was significantly correlated with the levels of uPAR and PAI-1. These results reveal that IL-8, VEGF, and PA system factors are contributed to tumor growth, invasion, and metastasis in CRC. Univariate analysis revealed that high levels of IL-8, VEGF, and uPAR were significantly associated with a shorter overall survival time; however, multivariate analysis identified only liver metastasis as an independent prognostic factor. In conclusion, IL-8 is responsible to tumor progression and liver metastasis of CRC, and the activation of PAS induced by IL-8 as well as VEGF may play an important role in the progression of CRC.

Impact of vascular endothelial growth factor-A expression, thrombospondin-2 expression, and microvessel density on the treatment effect of bevacizumab in metastatic colorectal cancer

PURPOSE

Bevacizumab is a monoclonal antibody to vascular endothelial growth factor-A (VEGF). In the pivotal trial in metastatic colorectal cancer (mCRC), addition of bevacizumab to first-line irinotecan, fluorouracil, and leucovorin (IFL) significantly prolonged median survival. The aim of these retrospective subset analyses was to evaluate VEGF, thrombospondin-2 (THBS-2), and microvessel density (MVD) as prognostic factors and/or predictors of benefit from bevacizumab.

PATIENTS AND METHODS

In the pivotal trial, 813 patients with untreated mCRC were randomly assigned to receive IFL plus bevacizumab or placebo. Of 312 tissue samples collected (285 primaries, 27 metastases), outcome data were available for 278 (153 bevacizumab, 125 placebo). Epithelial and stromal VEGF expression were assessed by in situ hybridization (ISH) and immunohistochemistry on tissue microarrays and whole sections. Stromal THBS-2 expression was examined by ISH on tissue microarrays. MVD was quantified by Chalkley count. Overall survival was associated with these variables in retrospective subset analyses.

RESULTS

In all subgroups, estimated hazard ratios (HRs) for risk of death were < 1 for bevacizumab-treated patients regardless of the level of VEGF or THBS-2 expression or MVD. Patients with a high THBS-2 score showed a nonsignificant improvement in survival following bevacizumab treatment (HR = 0.11; 95% CI, 0.02 to 0.51) compared to patients with a low score (HR = 0.65; 95% CI, 0.41 to 1.02); interaction analysis P = .22. VEGF or THBS-2 expression and MVD were not significant prognostic factors.

CONCLUSION

These exploratory analyses suggest that in patients with mCRC addition of bevacizumab to IFL improves survival regardless of the level of VEGF or THBS-2 expression, or MVD.

Relationship between urokinase-type plasminogen activator receptor and vascular endothelial growth factor expression and metastasis of gallbladder cancer

AIM: To investigate the relationship of urokinase type plasminogen activator receptor (uPAR) and vascular endothelial growth factor (VEGF) expression with clinical and pathological characteristics of human gallbladder cancer.

METHODS: uPAR and VEGF expressions in 68 gallbladder cancer tissues were detected with anti-receptor immunohistochemical stain.

RESULTS: Expression rate of uPAR was 57.4% (39/68), and VEGF 51.5% (35/68) in gallbladder cancer tissues. Expression of both uPAR and VEGF was significantly related to metastasis, but not significantly correlated with differentiation stage and size of gallbladder cancer.

CONCLUSION: Expression of uPAR and VEGF may be an invasive phenotype of gallbladder cancer and indicator for predicting prognoses, and uPAR expression is significantly correlated with the expression of VEGF.

An antibody to VEGF upregulates factor VIII via interleukin-1 in activated adrenal cortex-derived capillary endothelial cells

We have previously shown in an in vitro wounding system of cultured endothelial cells (EC) that vascular endothelial growth factor (VEGF(165)) treatment upregulated the level of factor VIII (FVIII) in the cells facing an experimental wound. The FVIII upregulation induced by VEGF(165) could be abolished by rhuMab VEGF, a humanized antibody that blocks VEGF functions and inhibits tumorigenesis. Because the thrombotic system is actively involved in angiogenesis, we further investigated the effects of rhuMab VEGF on the regulation of FVIII. Although non-disturbed cells distant from a wound were not affected by rhuMab VEGF treatment, FVIII was also significantly upregulated in the cells along the wound in cultures treated with the antibody alone. RhuMab VEGF stimulation of FVIII could be blocked by VEGF(165). When cells were treated with rhuMab VEGF and VEGF(165) combined together, the stimulation or inhibition of FVIII expression was dose-related and dependent on the amount of excess free rhuMab VEGF and rhuMab VEGF:VEGF(165) immune complexes. Thus, both VEGF(165) and rhuMab VEGF used as single reagents enhanced FVIII in activated endothelial cells, while the immune complexes suppressed the upregulation. Following rhuMab VEGF treatment, two distinct activated endothelial subpopulations that differ in their ability to internalize rhuMab VEGF and express interleukin-1 (IL-1) were identified. IL-1beta but not IL-1alpha appeared to be acting as a mediator between the two endothelial subpopulations as the FVIII upregulation induced by rhuMab VEGF could be totally abolished by treatment with type II soluble IL-1 receptor (sIL-1RII).

Urokinase-type plasminogen activator expression correlates with tumor angiogenesis and poor outcome in gastric cancer

Urokinase plasminogen activating system (PA system) and vascular endothelial growth factor (VEGF) were recently suggested to contribute synergistically to tumor progression. To evaluate the roles of the PA system and VEGF in gastric cancer, the effects of the PA system and VEGF on tumor angiogenesis and the survival of patients with gastric cancer were investigated. Cancer tissues from 101 gastric cancer patients were assayed immunohistochemically for expression of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), PA inhibitor-1 (PAI-1) and VEGF protein. The positive rates of uPA, uPAR, PAI-1, VEGF expression were 22.8%, 32.7%, 36.6% and 26.7%, respectively. Positive staining was observed in tumor cells (uPA, uPAR, VEGF), or in both tumor cells and stromal cells (PAI-1). The expressions of uPA, uPAR, PAI-1 and VEGF were significantly correlated with the clinicopathological factors: uPA, depth of tumor invasion, differentiation, lymphatic and vascular invasion; uPAR, tumor size, depth, lymph node involvement, differentiation, vascular invasion; PAI-1, tumor size, depth, lymph node involvement, differentiation, vascular invasion; VEGF, differentiation, vascular invasion. The microvessel density (MVD) assessed immunohistochemically was significantly higher in the patients with expression of uPA, uPAR or VEGF, and stepwise analysis identified uPA as an independent correlated factor with MVD. Furthermore, multivariate analysis demonstrated that depth of tumor invasion, lymph node involvement and uPA expression were independent prognostic factors. uPA is a key factor in the PA system, being associated with a poor outcome of gastric cancer, and contributing not only to invasive activity, but also to angiogenesis.

Cyclooxygenase-2 expression correlates with uPAR levels and is responsible for poor prognosis of colorectal cancer

Considering recent findings that cyclooxygensase-2 (COX-2) is involved in the progression of colorectal carcinoma (CRC), the role of COX-2 in promoting invasion and angiogenesis was investigated by evaluating the relationship of COX-2 expression to various clinicopathological variables, including plasminogen activating system (PA system) and vascular endothelial growth factor (VEGF). Tumor tissues from 71 patients with CRC were assayed to determine the antigen levels of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), and plasminogen activator inhibitor-1 and -2 (PAI-1 and PAI-2), as well as immunohistochemical expression of VEGF. COX-2 was assayed immunohistochemically in 56 patients. COX-2 expression was detected in cancer cells and it was also expressed by stromal cells in some patients. Fourteen patients (25%) were COX-2 positive, whereas 42 were negative. COX-2 expression was significantly related to lymphatic invasion (P = 0.0317), but was not related to microvessel density or VEGF expression. In the PA system, uPAR antigen levels were significantly higher in tumors with COX-2 expression than in tumors without (P = 0.0233). Univariate analysis showed that significant prognostic variables for survival were tumor size, lymph node involvement, lymphatic invasion, vascular invasion, liver metastasis, high uPAR level, and COX-2 expression, but only liver metastasis was an independent prognostic factor (P = 0.0065) in multivariate analysis. COX-2 expression was a more important prognostic indicator than any other factor except liver metastasis (P = 0.0526). The significant relationship between the presence of COX-2 protein and uPAR antigen levels contributed to the enhancement of tumor invasion and the poor outcome in patients with CRC.