Identification of the high-risk group for metastasis of gastric cancer cases by vascular endothelial growth factor receptor-1 overexpression in peripheral blood

Exploratory Analysis of Patients With Gastric/Gastroesophageal Junction Adenocarcinoma With or Without Liver Metastasis From the Phase 3 RAINBOW Study

PURPOSE

Liver metastasis (LM) is reported in approximately 40% of patients with advanced/metastatic gastric/gastroesophageal junction adenocarcinoma (metastatic esophagogastric adenocarcinoma; mGEA) and is associated with a worse prognosis. This post-hoc analysis from the RAINBOW trial reported the efficacy, safety, and biomarker outcomes of ramucirumab and paclitaxel combination treatment (RAM+PAC) in patients with (LM+) and without (LM-) LM at baseline.

MATERIALS AND METHODS

Patients (n=665) were randomly assigned on a 1:1 basis to receive either RAM+PAC (LM+: 150, LM-: 180) or placebo and paclitaxel (PL+PAC) (LM+: 138, LM-: 197). The overall survival (OS) and progression-free survival (PFS) were evaluated using stratified Kaplan-Meier and Cox regression models. The correlation of dichotomized biomarkers (VEGF-C, D; VEGFR-1,2) with efficacy in the LM+ versus LM- subgroups was analyzed using the Cox regression model with reported interaction P-values.

RESULTS

The presence of LM was associated with earlier progression than those without LM, particularly in patients receiving PL+PAC (hazard ratio [HR], 1.68). RAM+PAC treatment improved OS and PFS irrespective of LM status but showed greater improvement in LM+ than that in LM- (OS HR, 0.71 [LM+] vs. 0.88 [LM-]; PFS HR, 0.47 [LM+] vs. 0.76 [LM-]). Treatment-emergent adverse events were similar between patients with and without LM. No predictive relationship was observed between biomarker levels (VEGF-C, D; VEGFR-1,2) and efficacy outcome (OS, PFS) (all interaction P-values >0.05).

CONCLUSIONS

RAM provided a significant benefit, irrespective of LM status; however, its effect was numerically stronger in patients with LM. Therefore, RAM+PAC is a clinically meaningful therapeutic option for patients with mGEA and LM.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01170663.

Postoperative elevation in the plasma CCL2 level is a predictive biomarker of colorectal cancer recurrence

PURPOSE

There is currently no adequate biomarker for predicting colorectal cancer (CRC) recurrence. Chemokine (C-C motif) ligand 2 (CCL2) induces macrophages and fibroblasts to occupy metastatic niches in distant organs. The purpose of this study was to examine CCL2 as a potential predictive biomarker for CRC recurrence.

METHODS

Plasma samples (n = 402) were collected from 80 stage II/III/IV CRC cases and the relationship between CCL2 profiles and recurrence was investigated. The tumor immune response genes associated with CCL2 mRNA expression in a subgroup of 8 stage I/II CRC cases with 12 recurrent sites and The Cancer Genome Atlas database were also analyzed retrospectively.

RESULTS

Sixteen stage II/III/IV postoperative recurrent CRC cases experienced a significant increase in plasma CCL2 levels 6 months after surgery and continuously increased even after R0-1 resection. The 6-month postoperative CCL2 levels in recurrent cases of ≥ 1 year were significantly higher than in non-recurrent cases and recurrent cases of < 1 year. The CCL2 level in the primary tumor cases significantly correlated with the cytolytic activity, thus indicating a tumor immune response from the CD163-expressing macrophages.

CONCLUSION

Plasma CCL2 was found to be a predictive biomarker of postoperative CRC recurrence. CCL2 in metastatic sites derives from metastatic niches that surpass the host immune response.

Ultrasmall Fe@Fe3O4 nanoparticles as T1-T2 dual-mode MRI contrast agents for targeted tumor imaging

Targeted T₁-T₂ MRI contrast agents, which can eliminate the difficulty of image matching across multiple imaging instruments and permit specific localization of lesions, are promising candidates for more accurate diagnosis of tumors. In this study, ultrasmall Fe@Fe₃O₄ nanoparticles were designed and synthesized as T₁-T₂ dual-mode MRI contrast agents for accurate tumor imaging. First, to investigate the influence of nanoparticle size, Fe@Fe₃O₄ nanoparticles with diameters of 4, 8, and 12 nm were prepared, among which the 8 nm 3-(3,4-dihydroxyphenyl)propionic acid (DHCA)-modified nanoparticles exhibited the optimal T₁-T₂ dual-mode MRI performance. Next, to develop a tumor-targeted contrast agent, the DHCA-Fe@Fe₃O₄ nanoparticles were conjugated with the F56 peptide, which targets the vascular endothelial growth factor receptor, and the resulting F56-DHCA-Fe@Fe₃O₄ nanoparticles were found to exhibit good T₁-T₂ dual-mode imaging and tumor-targeting performance both in vitro and in vivo, indicating the nanoparticles represent a new research tool for accurate tumor diagnosis.

NOTCH Signaling Is Activated through Mechanical Strain in Human Bone Marrow-Derived Mesenchymal Stromal Cells

Skeletal development and remodeling of adult bone are critically controlled by activated NOTCH signaling in genetically modified mice. It is yet unclear whether NOTCH signaling is activated by mechanical strain sensed by bone cells. We found that expression of specific NOTCH target genes is induced after in vivo tibial mechanical loading in wild-type mice. We further applied mechanical strain through cyclic stretching in human bone marrow-derived mesenchymal stromal cells (BMSCs) in vitro by using a bioreactor system and detected upregulation of NOTCH target gene expression. Inhibition of the NOTCH pathway in primary BMSCs as well as telomerase-immortalized human BMSCs (hMSC-TERT) through the gamma-secretase inhibitor GSI XII blocked mechanotransduction and modulated actin cytoskeleton organization. Short-hairpin RNA gene silencing identified NOTCH2 as the key receptor mediating NOTCH effects on hMSC-TERT cells. Our data indicate a functional link between NOTCH activation and mechanotransduction in human BMSCs. We suggest that NOTCH signaling is an important contributor to molecular mechanisms that mediate the bone formation response to mechanical strain.

Vascular endothelial growth receptor 1 acts as a stress-associated protein in the therapeutic response to thalidomide

Thalidomide (THD) exhibits antitumor effects in several types of cancer. However, the failure of THD to inhibit tumor growth has also been observed in a number of murine models in vivo. The mechanism involved in the therapeutic failure of THD remains unclear. The present study demonstrated that, accompanied by growth-arresting and apoptosis-inducing effects (P<0.05), THD upregulated vascular endothelial growth factor receptor 1 (VEGFR1) expression levels in CT26 murine colorectal carcinoma cell lines. This in vitro phenomenon was also observed in various other cell lines, including human umbilical vein endothelial cells, SW480, SW620 and HCT116. Reactive oxygen species (ROS) levels were increased compared with those in the untreated control when cells were exposed to THD (P<0.05). Furthermore, results suggested that ROS suppression may have provoked the induction of VEGFR1 expression to some extent. In addition, the results revealed that THD failed to inhibit CT26 tumor growth in vivo and the expression of VEGFR1 protein was elevated by THD treatment compared with the control group in the murine colorectal tumor model (P<0.05). The results of further experiments suggested that VEGFR1 was elevated in response to various stress-associated situations, including chemotherapy, radiotherapy and thermotherapy, which indicate that it may act as a stress-associated protein. The present findings provide a foundation for the future study of VEGFR1-targeted therapy to enhance the efficacy of current therapies.

Pre-metastatic niches: organ-specific homes for metastases

It is well established that organs of future metastasis are not passive receivers of circulating tumour cells, but are instead selectively and actively modified by the primary tumour before metastatic spread has even occurred. Sowing the 'seeds' of metastasis requires the action of tumour-secreted factors and tumour-shed extracellular vesicles that enable the 'soil' at distant metastatic sites to encourage the outgrowth of incoming cancer cells. In this Review, we summarize the main processes and new mechanisms involved in the formation of the pre-metastatic niche.

125I-F56 Peptide as Radioanalysis Agent Targeting VEGFR1 in Mice Xenografted with Human Gastric Tumor

¹²⁵I-Radiolabeled F56 peptide was designed as a radioactive analogue of F56 (peptide WHSDMEWWYLLG) to bind with VEGFR1 receptor. It was synthesized in high radiochemical yield and specific activity. The in vitro stability of ¹²⁵I-F56 was tested, and the bioactivity of ¹²⁵I-F56 was confirmed by both cell uptake and binding affinity measurement in VEGFR1 positive BGC-823 cells. The time-radioactivity relationship and biodistribution of ¹²⁵I-F56 tracer were conducted using nude mice bearing human gastric carcinoma BGC-823, by noninvasive micro-SPECT/CT imaging. The tracer's tumor uptake was further confirmed by autoradiography and HE stain of ¹²⁵I-F56 in tumor tissues ex vivo. Those results demonstrated that ¹²⁵I-F56 holds great potential as a diagnostic agent in both molecular imaging and radioanalysis probe for gastric cancer.

VEGF, Flt-1, and microvessel density in primary tumors as predictive factors of colorectal cancer prognosis

Angiogenesis in the primary tumor is known to be necessary for tumor progression in adenocarcinomas of the colon. However, whether angiogenesis in the primary tumors of patients with colorectal cancer affects their prognosis has yet to be fully elucidated. The aim of the present study was to assess the association between selected pathoclinical parameters and overall survival of resectable colorectal cancer patients with the expression of angiogenesis-promoting factors, including vascular endothelial growth factor (VEGF) and Fms-like tyrosine kinase receptor (Flt-1), and microvessel density (MVD) in the primary tumor. VEGF and Flt-1 expression were assessed, as well as MVD (with anti-CD34) by immunohistochemistry in 139 archived primary colorectal cancer tissue samples. These results were compared with the overall survival of the patients and potential prognostic pathoclinical parameters. A higher MVD in the tumors expressing Flt-1 (P=0.04) was identified. However, there was no correlation between the pathoclinical parameters of colon cancer and Flt-1 expression, VEGF expression, or MVD in the tumor. Furthermore, the intensity of VEGF expression, Flt-1 expression and tumor MVD did not correlate with the overall survival of the patients. Therefore, although increased expression of VEGF and Flt-1 was correlated with an increased expression of MVD in the primary tumors of resectable colorectal cancer patients, these factors were not correlated with prognostic pathoclinical factors and overall survival.

A novel kinase mutation in VEGFR-1 predisposes its αC-helix/activation loop towards allosteric activation: Atomic insights from protein simulation

Vascular endothelial growth factor receptor 1 (VEGFR-1) has been implicated in diverse pathologies, including cancers. Although VEGFR-1 is considered as functionally impaired kinase, its decoy characteristics make it an important regulator of VEGFR-mediated signaling, particularly in tumor angiogenesis. VEGFR-1 conveys signaling via its tyrosine kinase (TK) domain whose activation is regulated by phosphorylation of specific tyrosine residues. Thus dysregulation of VEGFR-1 signaling, as reported in most of the cancers, might be a consequence of altered phosphorylation that could be attributed to genotypic variations in its TK domain. Considering the importance of TK domain of VEGFR-1, we carried out its mutational screening in 84 clinically validated and histopathologically confirmed colorectal cancer patients. By means of direct DNA sequencing and SNP analyses, eight novel variations, including one synonymous, two deletion, one missense and four intronic variations, were reported in the TK domain of VEGFR-1. rs730882263:C>G variation specifically reported in colon cancer, representing a single-atomic change (Sulfur to Oxygen) in the predicted (p.Cys1110Ser) protein, was observed as potentially deleterious variation as assessed by multiple single-nucleotide polymorphism prediction servers. Molecular dynamics simulations of VEGFR-1 Wt and (p.Cys1110Ser) variant models revealed major conformational changes in variant protein presumptuously generating an open conformation thereby exposing the activation domain and consequently increasing the probability of phosphorylation events: a condition frequently reported in cancers.

Radiolabeling and evaluation of (64)Cu-DOTA-F56 peptide targeting vascular endothelial growth factor receptor 1 in the molecular imaging of gastric cancer

Noninvasive imaging of vascular endothelial growth factor receptor 1 (VEGFR1) remains a great challenge in early diagnosis of gastric cancer. Here we reported the synthesis, radiolabeling, and evaluation of a novel (64)Cu-radiolabeled peptide for noninvasive positron emission tomography (PET) imaging of VEGFR1 positive gastric cancer. The binding of modified peptide WHSDMEWWYLLG (termed as F56) to VEGER-1 expressed in gastric cancer cell BCG823 has been confirmed by immune-fluorescence overlap. DOTA-F56 was designed and prepared by solid-phase synthesis and folded in vitro. (64)Cu-DOTA-F56 was synthesized in high radiochemical yield and high specific activity (S.A. up to 255.6 GBq/mmol). It has excellent in vitro stability. Micro-PET imaging of (64)Cu-DOTA-F56 identifies tumor in BCG823 tumor-bearing mice, while that of (18)F-FDG does not. Immunohistochemical analysis of excised BCG823 xenograft showed colocalization between the PET images and the staining of VEGFR1. These results demonstrated that (64)Cu-DOTA-F56 peptide has potential as a noninvasive imaging agent in VEGFR1 positive tumors.

Circulating tumor cells (CTCs) detected by RT-PCR and its prognostic role in gastric cancer: a meta-analysis of published literature

Objective

The prognostic significance of circulating tumor cells (CTCs) is controversial in gastric cancer (GC). We performed a meta-analysis of available studies to assess its prognostic value detected by RT-PCR for patients diagnosed with GC.

Methods

EMBase, PubMed, Ovid, Web of Science, Cochrane library and Google Scholar database search was conducted on all studies reporting the outcomes of interest. The studies were set up according to the inclusion/exclusion criteria. Meta-analysis was performed by using a random-effects model; hazard ratio (HR), risk ratio (RR) and their 95% confidence intervals (95% CIs) were set as effect measures. The information about trial design, results from the data was independently extracted. Heterogeneity of the studies was tested for each pooled analysis.

Results

Nineteen studies published matched the selection criteria and were included in this meta-analysis. CTCs positivity was significantly associated with poor relapse free survival (RFS) (HR 2.42, 95% CI: [1.94–3.02]; P<0.001) and poor overall survival (OS) (HR 2.42, 95% CI: [1.94–3.02]; P<0.001). CTCs positivity were also significantly associated with regional lymph nodes (RLNs) metastasis (RR 1.42, 95% CI: [1.20–1.68]; p<0.0001), depth of infiltration (RR 1.51, 95% CI: [1.27–1.79]; p<0.0001), vascular invasion (RR  = 1.43, 95% CI: [1.18–1.74], p = 0.0002) and TNM stage(I,II versus III) (RR 0.63, 95% CI [0.48–0.84]; p = 0.001).

Conclusion

Preoperative CTCs positivity indicates poor prognosis in patients with gastric cancer, and associated with poor clinicopathological prognostic factors.

Microarray analysis of cell cycle gene expression in adult human corneal endothelial cells

Corneal endothelial cells (ECs) form a monolayer that controls the hydration of the cornea and thus its transparency. Their almost nil proliferative status in humans is responsible, in several frequent diseases, for cell pool attrition that leads to irreversible corneal clouding. To screen for candidate genes involved in cell cycle arrest, we studied human ECs subjected to various environments thought to induce different proliferative profiles compared to ECs in vivo. Donor corneas (a few hours after death), organ-cultured (OC) corneas, in vitro confluent and non-confluent primary cultures, and an immortalized EC line were compared to healthy ECs retrieved in the first minutes of corneal grafts. Transcriptional profiles were compared using a cDNA array of 112 key genes of the cell cycle and analysed using Gene Ontology classification; cluster analysis and gene map presentation of the cell cycle regulation pathway were performed by GenMAPP. Results were validated using qRT-PCR on 11 selected genes. We found several transcripts of proteins implicated in cell cycle arrest and not previously reported in human ECs. Early G1-phase arrest effectors and multiple DNA damage-induced cell cycle arrest-associated transcripts were found in vivo and over-represented in OC and in vitro ECs. Though highly proliferative, immortalized ECs also exhibited overexpression of transcripts implicated in cell cycle arrest. These new effectors likely explain the stress-induced premature senescence that characterizes human adult ECs. They are potential targets for triggering and controlling EC proliferation with a view to increasing the cell pool of stored corneas or facilitating mass EC culture for bioengineered endothelial grafts.

Bone recurrence after curative resection of gastric cancer

BACKGROUND

Standard follow up for bone recurrence has not yet been established for gastric cancer after surgical resection. The aim of this study was to investigate the incidence of and related risk factors for bone recurrence after surgical resection of gastric cancer.

METHODS

A cohort of 3035 gastric cancer patients after curative resection was reviewed. We analyzed the patients who had bone scintigraphy before the surgery as well as during the follow-up period. The incidence of and the risk factors for bone recurrence after surgical resection of gastric cancer were investigated.

RESULTS

In a total of 1683 patients analyzed, bone recurrence was detected in 30 patients (1.8%). The incidence of bone recurrence was significantly higher in advanced gastric cancers than in early lesions (3.5 vs. 0.4%, p < 0.01). The most common recurrence site was the spine, followed by pelvic bone and rib. Most patients had multiple bone metastases. The median time for recurrence was 28 months (range 4-111) from the surgery. In univariate analysis, the recurrence rate was higher in the tumors with large size, undifferentiated pathology, location in the body, and advanced stage. In multivariate analysis, lymph node metastasis (N2/N3 vs. N0/N0I) was the most predictable risk factor for bone recurrence [hazard ratio [HR] 1.44 (95% confidence interval [CI] 1.217-1.694)] and depth of invasion (T2-4 vs. T1) was also independently associated with bone recurrence.

CONCLUSIONS

The incidence of bone recurrence was low after curative surgery in patients with gastric cancer. Intensive follow up with bone scintigraphy seems to be unnecessary in these patients.

Aberrations in Angiogenic Signaling and MYC Amplifications are Distinguishing Features of Angiosarcoma

Angiosarcomas are very aggressive, rare malignant tumors that originate from vascular or lymphatic vessels and primarily occur following chemical exposure or radiation therapy. Tumor response to either chemotherapy, radiation, or novel anti-angiogenic therapeutics is very low, and because little is known regarding the aberrant signaling that controls these tumors, personalized treatment options for many of these patients are lacking. In this review, we summarize several recent findings regarding the genomics of angiosarcomas, including new discoveries regarding aberrant angiogenic signaling and Myc amplification as key features of this tumor type.

Vascular endothelial growth factor receptor-1 mRNA overexpression in peripheral blood as a useful prognostic marker in breast cancer

INTRODUCTION

Identification of useful markers associated with poor prognosis in breast cancer patients is critically needed. We previously showed that expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood may be useful to predict distant metastasis in gastric cancer patients. However, expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood of breast cancer patients has not yet been studied.

METHODS

Real-time reverse transcriptase-PCR was used to analyze vascular endothelial growth factor receptor-1 mRNA expression status with respect to various clinical parameters in 515 patients with breast cancer and 25 controls.

RESULTS

Expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood was higher in breast cancer patients than in controls. Increased vascular endothelial growth factor receptor-1 mRNA expression was associated with large tumor size, lymph node metastasis and clinical stage. Patients with high vascular endothelial growth factor receptor-1 mRNA expression also experienced a poorer survival rate than those with low expression levels, including those patients with triple-negative type and luminal-HER2(-) type disease.

CONCLUSIONS

Expression of vascular endothelial growth factor receptor-1 mRNA in peripheral blood may be useful for prediction of poor prognosis in breast cancer, especially in patients with triple-negative type and luminal-HER2(-) type disease.

Expression of mesenchymal markers vimentin and fibronectin: the clinical significance in esophageal squamous cell carcinoma

BACKGROUND

The importance of mesenchymal characteristics has not been fully elucidated in esophageal cancer.

METHODS

Ten normal and 77 tumor specimens were collected. Microarray analysis was performed to analyze the expression patterns of epithelial markers, mesenchymal markers, epithelial mesenchymal transition (EMT)-related genes and stem cell markers. RT-PCR analysis was conducted to confirm the results of microarray analysis. Immunohistochemical analysis was performed to verify the level of protein expression. Statistical analysis was performed to investigate the correlation between selected genes and clinicopathological factors.

RESULTS

Microarray analysis showed that epithelial markers were significantly down-regulated whereas mesenchymal markers and EMT transcription factors were up-regulated in cancer cells. Two types of gene expression patterns were found in the clustering analysis, type 1 tumors and type 2 tumors. Type 1 tumor clusters did not reveal a fixed gene expression pattern whereas type 2 tumor clusters revealed up-regulation of mesenchymal markers EMT inducers and related genes. Vimentin and fibronectin were selected to distinguish between tumor types 1 and 2. Type 2 tumors showed significantly larger tumor sizes (p < 0.0001), wider ranges of lymph node metastasis (p = 0.0057), and a more severe clinical stage (p < 0.0001) than did type 1 tumors. The prognosis of patients with type 2 tumors was significantly worse than that of patients with type 1 tumors. Univariate and multivariate analyses revealed that classification of type 2 tumors was an independent prognostic factor.

CONCLUSIONS

The analysis of mesenchymal markers in esophageal cancer is useful in distinguishing patients with a poor prognosis.

α-fetoprotein, vascular endothelial growth factor receptor-1 and early recurrence of hepatoma

AIM: To investigate whether α-fetoprotein (AFP) and vascular endothelial growth factor receptor (VEGFR)-1 correlate with early recurrence of hepatoma/hepatocellular carcinoma (HCC).

METHODS: From 2000 to 2005, 114 consecutive patients with HCC underwent primary curative hepatectomy. The mean age was 60.7 (8.7) years and 94 patients were male. The median follow-up period was 71.2 mo (range: 43-100 mo). Immediately prior to commencing laparotomy, 5 mL bone marrow was aspirated from the sternum and collected in citrate-coated test tubes. The initial 2 mL of bone marrow aspirate was discarded in each case. AFP mRNA and VEGFR-1 mRNA in the bone marrow and peripheral blood (BM- and PH-AFP mRNA and BM- and PH-VEGFR-1 mRNA, respectively) were measured by real-time quantitative reverse transcription polymerase chain reaction. As normal controls, VEGFR-1 mRNA in the bone marrow and peripheral blood was also measured in 11 living liver donors. These data were evaluated for any correlation with early recurrence, comparing clinical and pathological outcomes.

RESULTS: The cut-off value of the BM-AFP mRNA and PH-AFP mRNA level in patients with HCC was set at 1.92 × 10^-7 and zero, respectively, based on data from the controls. A total of 34 (29.8%) and six (5.4%) patients were positive for BM-AFP mRNA and PH-AFP mRNA, respectively. The BM-VEGFR-1 mRNA levels in all HCC patients were higher than those in the normal controls, and this was the case also for PH-VEGFR-1mRNA. The 25-percentile values for the BM- and PH-VEGFR-1 mRNA in HCC patients were used as the cut-off values for assigning the patients into two groups based on these transcript levels. The High group for BM- VEGFR-1 mRNA contained 81 (71.1%) HCC cases and the Low group was assigned 33 (28.9%) patients. These numbers for PH-VEGFR-1mRNA were 78 (75.0%) and 26 (25.0%), respectively. HCC recurred in 80 patients; in the remnant liver in 48 cases, in the remnant liver and remote tissue in 20, and in the remote tissue alone in 12. BM-AFP mRNA-positive cases showed a significantly higher rate of early recurrence (within 1 year of surgical treatment) compared with BM-AFP mRNA-negative patients (P = 0.0091). Patients were classified into four groups according to the level/status of their BM-VEGFR-1 and BM-AFP mRNA as follows: group A (n = 23), BM-VEGFR-1/BM-AFP mRNA = low/negative; group B (n = 57) high/negative; group C (n = 10) low/positive; group D (n = 24), high/positive. This classification was found to correlate with a recurrence of this disease within 1 year (P = 0.0228). The disease-free survival curve of group A was significantly better than that of groups B, C or D (P = 0.0437, P = 0.0325, P = 0.0225). No other classification (i.e., PH-VEGF-R1/BM-AFP, BM-VEGF-R1/PH-AFP, and PH-VEGF-R1/PH-AFP mRNA) showed such a correlation.

CONCLUSION: The evaluation of BM-AFP and BM-VEGFR-1 mRNA in patients with HCC may be a valuable predictor of disease recurrence following curative resection.

Clinical significance of molecular detection of matrix metalloproteinase-1 in bone marrow and peripheral blood in patients with gastric cancer

PURPOSE

Matrix metalloproteinases are responsible for proteolytic degradation of basement membrane and extracellular matrix. In tumor tissues, elevated expression of matrix metalloproteinase-1 (MMP-1) has been associated with tumor invasion and metastasis. However, little is known about the expression of MMP-1 in peripheral blood (PB) and bone marrow (BM) in gastric cancer patients. Thus, the aim of the present study is to determine MMP-1 messenger RNA (mRNA) expression levels in BM and PB of patients with gastric cancer.

METHODS

The study group consisted of 857 patients with gastric cancer (577 males and 280 females) ranging in age from 27 to 87 years (average 61.6 years). MMP-1 mRNA expression levels in BM and PB were evaluated quantitatively by real-time reverse-transcription polymerase chain reaction (RT-PCR).

RESULTS

Expression of MMP-1 mRNA in BM and PB of patients with gastric cancer was significantly higher than in noncancer patients. High levels of MMP-1 mRNA expression were significantly associated with differentiated histology, tumor size, tumor invasiveness, lymph node metastasis, liver metastasis, and clinical stage. Particularly importantly, MMP-1 mRNA expression in PB was an independent factor of distant metastasis.

CONCLUSIONS

We disclosed that MMP-1 mRNA expression in peripheral blood and bone marrow of gastric cancer patients was very high, precisely reflecting staging of gastric cancer. MMP-1 mRNA expression in peripheral blood may be a useful marker for distant metastasis in gastric cancer.

Vascular endothelial growth factor receptor-1 activation mediates epithelial to mesenchymal transition in hepatocellular carcinoma cells

PURPOSE

To explore the molecular mechanism of Vascular endothelial growth factor receptor-1 (VEGFR-1) in invasion and metastasis of hepatocellular carcinoma.

METHODS

Reverse transcription polymerase chain reaction was performed to test expression of VEGFR-1 and its ligand VEGF-B19 in four hepatoma carcinoma cell. Fluorescent immunohistochemistry and western blotting were used to test the change of expression of E-cadherin or α-catenin.

RESULTS

VEGF-B-treated cells exhibited a change in E-cadherin from an organized, membrane-bound structure to a disorganized state that was dispersed throughout the cytoplasm. The maximal changes in E-cadherin were observed 24 hr after treatment of cells with VEGF-B. α-catenin was observed to translocate to the nucleus from its usual membrane-bound location 24 hr after treatment with either VEGF-B. Expression of the epithelial adhesion molecules E-cadherin was observed to decrease 48 hours after VEGF-B treatment. The nuclear expression of α-catenin was observed to increase 24 hr after treatment with VEGF-B.

CONCLUSIONS

VEGFR-1 on tumor cells may contribute to the aggressive behavior of hepatocellular carcinoma cells by inducing epithelial to mesenchymal transition (EMT). Targeting VEGFR-1 and downstream mediators of EMT may provide the foundation for the development of novel therapeutic approaches for this morbid and lethal disease.

Overt bone metastasis and bone marrow micrometastasis of early gastric cancer

Recently we encountered two cases of early gastric cancer (EGC) with bone metastasis after surgery. As they were not accompanied by overt liver, lung, or peritoneal metastasis, we examined the clinical significance of bone metastasis in EGC and its mechanisms by a review of the literature. We found only 10 cases of EGC complicated with overt bone metastasis in the English literature, so we also examined the Japanese reports of such cases. The main histologic type of cases of bone metastasis from EGC was the diffuse type, and there were long intervals between surgery and overt bone metastasis. One reason for such long intervals may have been the tumor dormancy. Two types of dormancy, dynamic and static, and two types of postoperative overt metastases, that of micrometastatic origin (normograde metastatic process) and that of bone marrow origin (retrograde metastatic process), were considered. We speculated that there may be specific routes by which the cancer cells infiltrate the bone marrow directly from EGC or lymph node metastasis. The procedures for diagnosing bone micrometastasis using monoclonal antibodies have recently been improved, but their accuracy rates are still not universally accepted. New, more reliable examinations are required to improve the survival rates of EGC.

Vascular endothelial growth factor receptor 1 expression in pelvic lymph nodes predicts the risk of cancer progression after radical prostatectomy

Recent studies suggest that vascular endothelial growth factor receptor (VEGFR) 1-positive hematopoietic progenitor cells precede the arrival of tumor cells and form clusters that may portend sites of future metastatic disease. The aim of the present study was to clarify whether VEGFR1 expression in pelvic lymph nodes predicts the risk of prostate cancer progression after radical prostatectomy. VEGFR1 expression in pelvic lymph nodes was examined by immunohistochemistry in 95 patients who underwent radical prostatectomy for prostate cancer. A cluster of VEGFR1-positive cells was considered positive. Expression of VEGFR1 in pelvic lymph nodes and biochemical recurrence after radical prostatectomy were examined by univariate survival analysis and multivariate Cox proportional hazards regression analysis. Thirty-seven of 79 lymph node-negative patients (46.8%) were found to have VEGFR1-positive cells in their pelvic lymph nodes, whereas 16 of 16 lymph node metastasis-positive patients (100%) had VEGFR1 clusters. There was a significant correlation between pathological stage and VEGFR1 staining (P = 0.002). Univariate analysis showed that pathological stage > or = pT3 and VEGFR1 expression in pelvic lymph nodes were each significantly associated with biochemical recurrence after radical prostatectomy. Multivariate analysis showed VEGFR1 expression to be an independent predictor of biochemical recurrence after radical prostatectomy (risk ratio = 5.715, P = 0.010), as was preoperative prostate-specific antigen (PSA) level > or = 10 ng/mL. Although larger validation studies are required, our results suggest that VEGFR1 expression in pelvic lymph nodes predicts the risk of biochemical PSA recurrence after radical prostatectomy.

Impact of vascular endothelial growth factor receptor 1, 2, and 3 expression on the outcome of patients with gastric cancer

Tumor angiogenesis is a multistep interactive process in which vascular endothelial growth factor (VEGF) and its receptors have a major role. However, the clinical significance of these molecules in gastric cancer (GC) remains unclear. Our study group comprised 86 patients who underwent gastrectomy and subsequently received chemotherapy for recurrent or residual tumor. Using immunohistochemical techniques, we analyzed the expression of VEGF receptors (VEGF-R) 1, 2, and 3. VEGF-R1 expression (defined as >5% staining) was found in the tumor cells of 65 tumors (76%) and in the stromal vessels of 36 tumors (42%). VEGF-R2 expression was found in tumor cells and stromal vessels of 0 and 46 tumors (0 and 53%), respectively, and VEGF-R3 expression was found in tumor cells and stromal vessels of 0 and 75 tumors (0 and 87%), respectively. Univariate analysis revealed that VEGF-R expression correlated with shorter survival (VEGF-R1 in stromal vessels, P = 0.001; VEGF-R2 in stromal vessels, P = 0.009; VEGF-R3 in stromal vessels, P = 0.005) and lower response to S-1 (VEGF-R1 in stromal vessels, P = 0.039). Multivariate analysis of potential prognostic factors showed that VEGF-R1 and VEGF-R2 in stromal vessels were independent predictors of poor outcome. Our data suggest that VEGF-R expression can be a predictor of unfavorable clinical outcome in GC. VEGF-R are promising candidates as therapeutic targets.

Hematogenous metastasis in gastric cancer requires isolated tumor cells and expression of vascular endothelial growth factor receptor-1

PURPOSE

Recent studies of cancer metastasis have focused on the role of premetastatic gene expression and circulating tumor cells. We did a blind prospective study in gastric cancer to assess the significance of isolated tumor cells (ITC) and to test the hypothesis that vascular endothelial growth factor receptor-1 (VEGFR-1) is expressed within the bone marrow at tumor-specific, premetastatic sites.

EXPERIMENTAL DESIGN

Both bone marrow and peripheral blood samples from 810 gastric cancer patients were collected at the Central Hospital, National Cancer Center (Tokyo, Japan). The samples were transferred to Kyushu University Hospital (Beppu, Japan) where they were analyzed by quantitative real-time reverse transcription-PCR for three epithelial cell markers, carcinoembryonic antigen, cytokeratin-19, and cytokeratin-7, as well as VEGFR-1.

RESULTS

ITCs were observed in peripheral blood and bone marrow even in early stages of gastric cancer. The frequency of ITC in bone marrow was significantly associated with the stage of disease by ANOVA (P < 0.01). Gastric cancer metastasized when ITCs were observed in the presence of VEGFR-1. In the 380 patients who were ITC negative and showed low VEGFR-1 expression, synchronous (at the time of surgery) and heterochronous (recurrent) metastases were not observed.

CONCLUSIONS

ITCs circulate even in early stages of disease. Furthermore, elevated expression of VEGFR-1 facilitates the establishment of hematogenous metastases in gastric cancer. This study indicates that the simultaneous presence of ITC and VEGFR-1 expression at premetastatic sites is clinically significant for disease progression.

Lymphatic and/or blood vessel invasion in gastric cancer: relationship with clinicopathological parameters, biological factors and prognostic significance

BACKGROUND

Lymphatic and/or blood vessel tumoral invasion (LBVI) is a common histopathologic finding of gastric carcinomas, which could make it an additional cost efficient marker and help in the detection of patients at risk for recurrence.

MATERIALS AND METHODS

The subjects of this study were 144 patients with primary gastric adenocarcinoma, who consecutively underwent surgery. LBVI was evaluated by H&E staining and complementary with immunohistochemical staining with anti-CD34. Intratumoral levels of EGFR were analyzed with a radioligand technique, whereas c-erbB-2 and tPA were determined by ELISA methods; pS2, cathepsin D and hyaluronic acid by immunoradiometric assays; and VEGFR-1 and -2 by immunohistochemical assays. The mean follow-up period for these patients was 33.1 months.

RESULTS

LBVI was present in 46 patients (31.9%). The presence of LBVI correlated significantly with tumor stage, lymph node involvement, surgical resectability, histological type and histological grade, being present in a higher percentage among II-IV tumor stage (P = 0.0001), poorly differentiated (P = 0.01), diffuse type (P = 0.009), R1-R2 (P = 0.002) and lymph node-positive (P = 0.005) tumors. In addition, statistical analysis demonstrated that LBVI was significantly associated with a poorer overall patients' survival in the univariate analysis (P = 0.0001) as well as in the multivariate analysis (P = 0.009). However, our results failed to show any significant relationship between LBVI and any of the intratumoral biological parameters studied.

CONCLUSION

LBVI provides additional useful information that could be applied to identify gastric cancer patients at risk for recurrence, who might be candidates for further adjuvant therapies.