Vascular endothelial growth factor-C and its receptor VEGFR-3 in non-small-cell lung cancer: concurrent expression in cancer cells from primary tumour and metastatic lymph node

Recent advances and future directions on small molecule VEGFR inhibitors in oncological conditions

"A journey of mixed emotions" is a quote that best describes the progress chart of vascular endothelial growth factor receptor (VEGFR) inhibitors as cancer therapeutics in the last decade. Exhilarated with the Food and Drug Administration (FDA) approvals of numerous VEGFR inhibitors coupled with the annoyance of encountering the complications associated with their use, drug discovery enthusiasts are on their toes with an unswerving determination to enhance the rate of translation of VEGFR inhibitors from preclinical to clinical stage. The recently crafted armory of VEGFR inhibitors is a testament to their growing dominance over other antiangiogenic therapies for cancer treatment. This review perspicuously underscores the earnest attempts of the researchers to extract the antiproliferative potential of VEGFR inhibitors through the design of mechanistically diverse structural assemblages. Moreover, this review encompasses sections on structural/molecular properties and physiological functions of VEGFR, FDA-approved VEGFR inhibitors, and hurdles restricting the activity range/clinical applicability of VEGFR targeting antitumor agents. In addition, tactics to overcome the limitations of VEGFR inhibitors are discussed. A clear-cut viewpoint transmitted through this compilation can provide practical directions to push the cart of VEGFR inhibitors to advanced-stage clinical investigations in diverse malignancies.

Association of plasma NRP2 and VEGF-C levels with prostate cancer disease severity

BACKGROUND

Neuropilin 2 (NRP2) expression in tissue is an independent prognostic factor for aggressive prostate cancer. Since the NRP2 pathway activation is thought to occur in part through secondary resistance, quantification of NRP2 in initial tissue biopsy specimens collected at diagnosis may have limited utility in identifying patients at highest risk for morbidity and mortality. Given that metastatic tissue is only occasionally obtained for analysis, there is a need for development of a plasma biomarker indicative of NRP2 pathway activation to potentially inform prostate cancer prognosis. Therefore, we investigated if plasma levels of NRP2 or vascular endothelial growth factor C (VEGF-C), a known soluble ligand of NRP2, are prognostic for prostate cancer. We hypothesized that plasma NRP2 and VEGF-C would be associated with more advanced disease or relapsed disease.

METHODS

NRP2 and VEGF-C levels were quantified by enzyme-linked immunoassay in plasma samples obtained from 145 prostate cancer patients in an opportunistic biobank. These patients were either (1) newly diagnosed (N = 28), (2) in remission (N = 56), or (3) relapsed disease (N = 61). Plasma samples from 15 adult males without known malignancy served as a comparator cohort. Statistical analysis was performed to investigate the association of plasma NRP2/VEGF-C with patient outcomes, adjusting for age, race, prostate-specific antigen (PSA), Gleason score, and tumor stage at diagnosis.

RESULTS

Neither NRP2 nor VEGF-C levels were significantly different in cancer patients compared to noncancer controls. We observed no clear association between plasma NRP2 and disease severity. Increased plasma VEGF-C was significantly associated with disease remission and correlated with Stage I/II and intermediate-risk Gleason score. Neither NRP2 nor VEGF-C correlated with PSA level.

CONCLUSIONS

Although tissue NRP2 expression correlates with severe disease, this was not observed for plasma NRP2. Plasma NRP2 levels did not correlate with disease severity or relapse. VEGF-C was highest in patients in remission and with less severe disease. Future investigation is needed to identify noninvasive methods to assess tumor NRP2 status.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Efficacy and safety of antiangiogenic agents or chemotherapy plus EGFR-TKIs in advanced non-small cell lung cancer: A systematic review and network meta-analysis

BACKGROUND

The combination of antiangiogenic agents with epidermal growth factor receptor inhibitors (EGFR-TKIs) and chemotherapy with EGFR-TKIs are the most common combination treatment options in epidermal growth factor receptor (EGFR) positive non-small cell lung cancer (NSCLC). This network meta-analysis was performed to evaluate the differences between them.

METHODS

We searched the PubMed, EMBASE and the Cochrane Controlled Trials Register up to August 2022. The primary outcomes were progression-free survival (PFS) and objective response rate (ORR). The secondary endpoints were overall survival (OS), disease control rate (DCR) and adverse events (AEs). The data of hazard ratio (HR) or risk ratio (RR) with their corresponding 95% confidence intervals (CIs) were extracted in the studies. A network meta-analysis (NMA) was used to indirectly compare the efficacy and safety of antiangiogenic agents plus EGFR-TKIs and chemotherapy plus EGFR-TKIs.

RESULTS

Pooled data of included studies were demonstrated that chemotherapy plus EGFR-TKIs had a benefit in ORR compared to antiangiogenic agents plus EGFR-TKIs in patients with EGFR mutated NSCLC (RR = 1.1, 95% CI: 1.0-1.2). However, there were no significant differences in PFS, OS and DCR between in the two group (PFS: HR = 1.0, 95% CI: 0.74-1.6; OS: HR = 0.78, 95% CI: 0.45-1.5; DCR: RR = 1.0, 95% CI: 0.94-1.1). The common treatment-related AEs in the two groups were relatively manageable.

CONCLUSION

Based on the efficacy and safety, the combination of chemotherapy with EGFR-TKIs is considered the best combination treatment options in advanced NSCLC with EGFR mutation.

Recent progress on FAK inhibitors with dual targeting capabilities for cancer treatment

Focal adhesion kinase (FAK, also known as PTK2) is a tyrosine kinase that regulates integrin and growth factor signaling pathways and is involved in the migration, proliferation and survival of cancer cells. FAK is a promising target for cancer treatment. Many small molecule FAK inhibitors have been identified and proven in both preclinical and clinical studies to be effective inhibitors of tumor growth and metastasis. There are many signaling pathways, such as those involving FAK, Src, AKT, MAPK, PI3K, and EGFR/HER-2, that provide survival signals in cancer cells. Dual inhibitors that simultaneously block FAK and another factor can significantly improve efficacy and overcome some of the shortcomings of single-target inhibitors, including drug resistance. In this review, the antitumor mechanisms and research status of dual inhibitors of FAK and other targets, such as Pyk2, IGF-IR, ALK, VEGFR-3, JAK2, EGFR, S6K1, and HDAC2, are summarized, providing new ideas for the development of effective FAK dual-target preparations.

Correlation between the Expression of VEGF and Ki67 and Lymph Node Metastasis in Non-small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background

Lymph node metastasis is the most common and important way of metastasis in NSCLC and is also the most important factor affecting lung cancer stage and prognosis. It is very important to analyze the relationship between the expression of vascular endothelial growth factor (VEGF) and Ki67 and lymph node metastasis (LNM) in non-small-cell lung cancer (NSCLC).

Methods

We searched the PubMed, EMBASE, and Cochrane Library and conducted meta-analyses using the R meta-package. Relative risk (RR) with a 95% confidence interval (95% CI) was the main indicator.

Results

Totally, 18 studies were considered eligible, with 4521 patients, including 1518 LNM-positive patients and 3033 LNM-negative patients. The incidence of LNM in Ki67-negative patients was lower than that in Ki67-positive patients (RR = 0.66, 95% CI: 0.44, 0.98). The incidence of LNM in VEGF-A-negative patients was lower than that in VEGF-A-positive patients (RR = 0.64, 95% CI: 0.49, 0.83). The incidence of LNM in VEGF-C negative patients was lower than that in VEGF-C positive patients (RR = 0.68, 95% CI: 0.53, 0.88). The incidence of LNM in VEGF-D negative and positive patients were of no significant differences (RR = 0.84, 95% CI: 0.61, 1.14).

Conclusion

The high expression of Ki67, VEGF-A, and VEGF-C significantly increases the risk of lymph node metastasis in NSCLC, while the VEGF-D expression has no correlation with lymph node metastasis. The expression levels of Ki67, VEGF-A, and VEGF-C show a good potential for lymph node metastasis prediction.

Hypoxia in Lung Cancer Management: A Translational Approach

Simple Summary

Hypoxia is a common feature of lung cancers. Nonetheless, no guidelines have been established to integrate hypoxia-associated biomarkers in patient management. Here, we discuss the current knowledge and provide translational novel considerations regarding its clinical detection and targeting to improve the outcome of patients with non-small-cell lung carcinoma of all stages.

Abstract

Lung cancer represents the first cause of death by cancer worldwide and remains a challenging public health issue. Hypoxia, as a relevant biomarker, has raised high expectations for clinical practice. Here, we review clinical and pathological features related to hypoxic lung tumours. Secondly, we expound on the main current techniques to evaluate hypoxic status in NSCLC focusing on positive emission tomography. We present existing alternative experimental approaches such as the examination of circulating markers and highlight the interest in non-invasive markers. Finally, we evaluate the relevance of investigating hypoxia in lung cancer management as a companion biomarker at various lung cancer stages. Hypoxia could support the identification of patients with higher risks of NSCLC. Moreover, the presence of hypoxia in treated tumours could help clinicians predict a worse prognosis for patients with resected NSCLC and may help identify patients who would benefit potentially from adjuvant therapies. Globally, the large quantity of translational data incites experimental and clinical studies to implement the characterisation of hypoxia in clinical NSCLC management.

Identification of differentially expressed genes between primary lung cancer and lymph node metastasis via bioinformatic analysis

Lung cancer (LC), with its high morbidity and mortality rates, is one of the most widespread and malignant neoplasms. Mediastinal lymph node metastasis (MLNM) severely affects postoperative survival of patients with LC. Additionally, the molecular mechanisms of LC with MLNM (MM LC) remain not well understood. To identify the key biomarkers in its carcinogenesis and development, the datasets GSE23822 and GSE13213 were obtained from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) were identified, and the Database for Annotation, Visualization and Integrated Discovery was used to perform functional annotations of DEGs. Search Tool for the Retrieval of Interacting Genes and Cytoscape were utilized to obtain the protein-protein interaction (PPI) network, and to analyze the most significant module. Subsequently, a Kaplan-Meier plotter was used to analyze overall survival (OS). Additionally, one co-expression network of the hub genes was obtained from cBioPortal. A total of 308 DEGs were identified in the two microarray datasets, which were mainly enriched during cellular processes, including the Gene Ontology terms ‘cell’, ‘catalytic activity’, ‘molecular function regulator’, ‘signal transducer activity’ and ‘binding’. The PPI network was composed of 315 edges and 167 nodes. Its significant module had 11 hub genes, and high expression of actin β, MYC, arginine vasopressin, vesicle associated membrane protein 2 and integrin subunit β1, and low expression of NOTCH1, synaptojanin 2 and intersectin 2 were significantly associated with poor OS. In summary, hub genes and DEGs presented in the present study may help identify underlying targets for diagnostic and therapeutic methods for MM LC.

Tumor-associated lymphangiogenesis predicts unfavorable prognosis of intrahepatic cholangiocarcinoma

Background

Tumor-associated lymphangiogenesis is considered significant in number of solid malignancies. However, its impact on prognosis of intrahepatic cholangiocarcinoma (ICC) after resection remains further confirmation. Herein, we conducted this study to evaluate prognostic impact of tumor-associated lymphangiogenesis in patients with ICC.

Methods

Extent of tumor-associated lymphangiogenesis of ICC was evaluated by quantifying microlymphatic vessel density (MLVD) from immunohistochemical staining of a lymphatic endothelial-specific antibody (podoplanin). Clinicopathological characteristics were comprehensively analyzed to identify MLVD-associated factors. The patients were stratified into high and low MLVD groups according to the distinctive correlation between the MLVD and overall survival using the Spearman’s correlation test. Kaplan-Meier estimation was performed to confirm prognostic impact of MLVD in patients with ICC. Univariate and multivariate analyses were performed using the Cox proportional hazard model.

Results

The MLVD between 4 to 12 counts showed inverse proportion to the overall survival (Spearman’s r = − 0.66; 95% confidence interval [CI], − 0.82 to − 0.39; p <  0.0001), which was set as a cut-off for the high MLVD group, whereas the MLVD between 13 to 25 showed no correlation to the overall survival (r = − 0.11; 95% CI, − 0.38 to 0.19; p = 0.4791). The high MLVD group showed more frequent lymph node metastasis (p <  0.001) and were more likely to suffer from recurrence of the tumor compared to the low MLVD group (p <  0.001). The high MLVD was found to be independently associated with reduced overall and recurrence-free survival. The 5-year overall survival of the patients with high MLVD was significantly lower compared to those with low MLVD (0% vs 48%).

Conclusions

Our study reveals that tumor-associated lymphangiogenesis is significantly associated with increased lymphatic metastasis, recurrence of the tumor, and reduced overall survival in patients with ICC, thus providing guidance when estimating postresection prognosis.

Effect of High VEGF-C mRNA Expression on Achievement of Complete Remission in Adult Acute Myeloid Leukemia

Although vascular endothelial growth factor-C (VEGF-C) is known to be expressed in acute myeloid leukemia (AML) blasts, the relevance of VEGF-C in the clinical setting remains to be fully explored. We examined the effect of VEGF-C on achievement of complete remission (CR) in adult de novo AML and immune cell population profiles according to VEGF-C mRNA expression. In comparison of VEGF-C expression between the no-CR and CR groups, the CR group showed a trend toward higher levels of plasma VEGF-C (P = .088), whereas mRNA expression of VEGF-C was downregulated (P = .008). Next, patients with continuous data for VEGF-C were divided into two groups (low vs. high) by a ROC curve analysis. The low- versus high-level groups for plasma VEGF-C (RR of 0.20, P = .030), mRNA expression of VEGF-C (RR of 18.75, P = .003), and the ratio of plasma level to mRNA expression (RR of 0.05, P = .007) were potential predictors of CR on univariate analysis. After adjusting for potential clinical factors including genetic group, multivariate analyses revealed that high VEGF-C mRNA expression was an independent risk factor for failure of induction chemotherapy. Furthermore, patients with high VEGF-C mRNA expression had a lower frequency of NKT and CD8+ cells and showed a trend for a lower frequency of NK cells. These results suggest that interruption of VEGF-C signaling might be a potential therapeutic target for antileukemic treatment in AML patients.

Prognostic and clinical significance of VEGFR-3 in gastric cancer: A meta-analysis

BACKGROUND

Recent studies have suggested that VEGFR-3 is involved in the development of gastric cancer, however, the results are contradictory. Hence, we conducted a meta-analysis to assess the correlation between VEGFR-3 and the clinicopathological characteristics of gastric cancer to assess its prognostic value.

METHODS

An electronic search for relevant articles was conducted in PubMed, Cochrane Library, Web of Science, EMBASE database, and Chinese CNKI. Correlations between VEGFR-3 expression and clinicopathological features and survival outcomes were analyzed. Pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Positive VEGFR-3 expression was not correlated with gender or tumor differentiation. However, high levels of VEGFR-3 expression were significantly associated with depth of invasion and lymph node metastasis. Moreover, VEGFR-3 expression was associated with poor three year and five year overall survival rates (OS) in GC patients.

CONCLUSIONS

Our meta-analysis found that VEGFR-3 expression was associated with depth of invasion and lymph node metastasis in gastric cancer. The results suggest that VEGFR-3 may be a useful prognostic biomarker for gastric cancer.

Expression of CXCR4 and VEGF-C is correlated with lymph node metastasis in non-small cell lung cancer

BACKGROUND

This study investigated the correlations between CXCR4 and VEGF-C expression and lymph node metastasis in non-small cell lung cancer (NSCLC).

METHODS

Tumor specimens, lymph nodes, and normal lung tissues were obtained from 110 NSCLC patients who underwent complete resection. Quantitative reverse transcription-PCR and immunohistochemistry assays were conducted to evaluate messenger RNA (mRNA) and protein expression of CXCR4 and VEGF-C. Logistic regression analysis was performed to determine the independent risk factors for lymph node metastasis in NSCLC.

RESULTS

CXCR4 and VEGF-C mRNA expression were observed in 78 (70.9%) and 64 (58.2%) lung cancer tissues, while CXCR4 and VEGF-C protein expression were observed in 76 (69.9%) and 58 (52.7%) lung cancer tissues, respectively. The expression rates of CXCR4 and VEGF-C mRNA in metastatic lymph nodes were 84.8% and 66.7%, which were higher than that in non-metastatic lymph nodes (27.3% and 18.2%), respectively. Logistic regression analysis revealed that positive expressions of CXCR4 and VEGF-C mRNA were independent risk factors for lymph node metastasis in NSCLC. Furthermore, combined expression of CXCR4 and VEGF-C showed a much higher odds ratio than CXCR4 or VEGF-C expression alone.

CONCLUSIONS

CXCR4 and VEGF-C were highly expressed in lung cancer tissues and metastatic lymph nodes. CXCR4 and VEGF-C expression levels were significantly correlated with lymph node metastasis in NSCLC. CXCR4 and VEGF-C might synergically promote lymphatic metastasis in lung cancer and might be a clinical predictor of lymph node metastasis in NSCLC patients.

Synaptonemal complex protein 3 is associated with lymphangiogenesis in non-small cell lung cancer patients with lymph node metastasis

Background

The interaction of vascular endothelial growth factor-C (VEGF-C)/VEGF-D/VEGF receptor-3 is considered to be a major driver of lymphangiogenesis, however the mechanism of this process remains unclear. We aimed to investigate the possible lymphangiogenic significance of synaptonemal complex protein 3 (SCP3) in non-small cell lung cancer (NSCLC).

Methods

The expression of SCP3, VEGF-C, and VEGF-D were measured and examined a correlation between SCP3 and VEGF-C or VEGF-D in various human lung cancer cell lines. Subsequently, we assessed SCP3, VEGF-A, VEGF-B, VEGF-C, and VEGF-D expression in archival tumor tissues from 89 NSCLC patients with lymph node (LN) metastasis by combined immunohistochemistry with quantitative digital image analysis.

Results

Positive correlations between SCP3 and VEGF-C expression (R² = 0.743) and VEGF-D expression (R² = 0.932) were detected in various human lung cancer cell lines. The high expression of SCP3, VEGF-A, VEGF-B, VEGF-C, and VEGF-D were detected in 24 (27.0%), 22 (24.7%), 27 (30.3%), 27 (30.3%), and 24 cases (27.0%), respectively. Notably, SCP3 positively correlated with VEGF-C and VEGF-D expression (for both, P < 0.001) and negatively correlated with VEGF-A and VEGF-B expression (P = 0.029 and P = 0.026, respectively). In multivariate analysis of patients with LN metastasis, SCP3 expression predicted worse overall survival (hazard ratio = 1.86, P = 0.008).

Conclusions

SCP3 is associated with lymphangiogenesis and provides insight into the SCP3-VEGF-C/VEGF-D axis based cancer therapy strategy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1241-5) contains supplementary material, which is available to authorized users.

Pien Tze Huang suppresses VEGF-C-mediated lymphangiogenesis in colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies worldwide. The majority of patients are not suitable for surgery due to the presence of metastatic disease at the time of diagnosis, which has led to a high mortality rate for patients with CRC. Lymphangiogenesis, formation of new lymphatic vessels, plays an critical role in cancer progression particularly in cancer metastasis. Vascular endothelial growth factor-C (VEGF-C) has been previously demonstrated to play a pivotal role in cancer metastasis and therefore has become an attractive target for anticancer treatments. Pien Tze Huang (PZH) is a well-known traditional Chinese formula, which has exhibited significant therapeutic effects against CRC. However, the molecular mechanisms underlying its anticancer effects, particularly in regards to antimetastasis activity, still require further elucidation. In the present study, we evaluated the effects of PZH on cell migration and VEGF-C expression using various human CRC cell lines. Moreover, using a VEGF‑C-stimulated human lymphatic endothelial cell (HLEC) model, we demonstrated that PZH suppresses lymphangiogenesis by attenuating cell migration and tube formation. This indicates that PZH possesses significant antimetastatic activity. Moreover, suppression of lymphangiogenesis by PZH via the downregulation of VEGF-C may be a potential molecular mechanism by which PZH inhibits metastasis in CRC.

Use of NRP1, a novel biomarker, along with VEGF-C, VEGFR-3, CCR7 and SEMA3E, to predict lymph node metastasis in squamous cell carcinoma of the tongue

Lymph node (LN) metastasis has been suggested as a major prognostic factor for oral cancer. Knockdown of the growth factors and receptors involved in these metastatic mechanisms could significantly reduce LN metastasis and improve the survival of oral cancer patients after treatment. The present study, therefore, aimed to evaluate the expression levels of the following growth factors and receptors in squamous cell carcinoma (SCC) of the tongue: the vascular endothelial growth factor (VEGF)‑C and VEGF‑D, which bind to the cell surface tyrosine kinase receptor VEGF receptor‑3 (VEGFR‑3); C‑C motif chemokine receptor 7 (CCR7); neuropilin (NRP)1 and NRP2; and semaphorin 3E (SEMA3E). Furthermore, we assessed microvessel density (MVD) and lymphatic vessel density (LVD) to demonstrate the correlation between these factors and regional LN metastasis, with respect to the clinicopathological features. Finally, we analyzed the correlation between these proteins and overall or disease‑free survival, in order to demonstrate their prognostic value. Univariate analysis revealed a significant association between LN metastasis and the expression levels of VEGF‑C, VEGFR‑3, CCR7, NRP1, and SEMA3E, as well as LVD, in SCC cells. In contrast, multivariate analysis identified associations between LN metastasis and NRP1 expression, as well as between LN metastasis and LVD; however, no correlation was found between LN metastasis and the expression levels of the other proteins. The expression levels of VEGF‑C, VEGFR‑3, NRP1, and SEMA3E, as well as LVD, were correlated with disease‑free survival time. These results indicate that LN metastasis is associated with poor survival in SCC. This study suggests that NRP1 expression and LVD are independent factors that are likely to predict the risk of LN metastasis in SCC of the tongue, whereas the expression of VEGF‑C, VEGFR‑3, CCR7, and SEMA3E are non‑independent predictive factors.

Prognostic impact of elevation of vascular endothelial growth factor family expression in patients with non-small cell lung cancer: an updated meta-analysis

BACKGROUND

The vascular endothelial growth factor family has been implicated in tumorigenesis and metastasis. The prognostic value of each vascular endothelial growth factor family member, particular VEGF/ VEGFR co-expression, in patients with non-small lung cancer remains controversial.

MATERIALS AND METHODS

Relevant literature was identified by searching PubMed, EMBASE and Web of Science. Studies evaluating expression of VEGFs and/or VEGFRs by immunohistochemistry or ELISA in lung cancer tissue were eligible for inclusion. Hazard ratios (HRs) and 95% confidence intervals (CIs) from individual study were pooled by using a fixed- or random-effect model, heterogeneity and publication bias analyses were also performed.

RESULTS

74 studies covering 7,631 patients were included in the meta-analysis. Regarding pro-angiogenesis factors, the expression of VEGFA (HR=1.633, 95%CI: 1.490-1.791) and VEGFR1 (HR=1.924, 95%CI: 1.220-3.034) was associated separately with poor survival. Especially, VEGFA over-expression was an independent prognostic factor in adenocarcinoma (ADC) (HR=1.775, 95%CI: 1.384-2.275) and SCC (HR=2.919, 95%CI: 2.060-4.137). Co-expression of VEGFA/VEGFR2 (HR=2.011, 95%CI: 1.405-2.876) was also significantly associated with worse survival. For lymphangiogenesis factors, the expression of VEGFC (HR=1.611, 95%CI: 1.407-1.844) predicted a poor prognosis. Co-expression of VEGFC/VEGFR3 (HR=2.436, 95%CI: 1.468-4.043) emerged as a preferable prognostic marker.

CONCLUSIONS

The expression of VEGFA (particularly in SCC and early stage NSCLC), VEGFC, VEGFR1 indicates separately an unfavorable prognosis in patients with NSCLC. Co-expression VEGFA/ VEGFR2 is comparable with VEGFC/VEGFR3, both featuring sufficient discrimination value as preferable as prognostic biologic markers.

Lymphangiogenic Markers and Their Impact on Nodal Metastasis and Survival in Non-Small Cell Lung Cancer--A Structured Review with Meta-Analysis

Background

In non-small cell lung cancer (NSCLC), nodal metastasis is an adverse prognostic factor. Several mediating factors have been implied in the development of nodal metastases and investigated for predictive and prognostic properties in NSCLC. However, study results differ. In this structured review and meta-analysis we explore the published literature on commonly recognized pathways for molecular regulation of lymphatic metastasis in NSCLC.

Methods

A structured PubMed search was conducted for papers reporting on the expression of known markers of lymhangiogenesis in NSCLC patients. Papers of sufficient quality, presenting survival and/or correlation data were included.

Results

High levels of vascular endothelial growth factor C (VEGF-C, HR 1.57 95% CI 1.34–1.84) and high lymphatic vascular density (LVD, HR 1.84 95% CI 1.18–2.87) were significant prognostic markers of poor survival and high expression of VEGF-C, vascular endothelial growth factor receptor 3 (VEGFR3) and LVD was associated with lymph node metastasis in NSCLC.

Conclusion

Lymphangiogenic markers are prognosticators of survival and correlate with lymph node metastasis in NSCLC. Their exact role and clinical implications should be further elucidated.

[Inhibitory effect of endostar on lymphangiogenesis in non-small cell lung cancer and its effect on circulating tumor cells]

背景与目的

血管内皮抑素可以抑制肿瘤新生血管的生成，但对肿瘤微淋巴管的形成与发展是否存在抑制效应引起我们关注。本研究旨在探讨重组人血管内皮抑素（recombinant human endostatin injection）对非小细胞肺癌组织中血管内皮生长因子（vascular endothelial growth factor, VEGF）-C、VEGF-D和VEGF受体（VEGFR）-3表达及对外周血循环肿瘤细胞数目的影响。

方法

荷瘤裸鼠随机分为空白对照组、顺铂组、不同浓度重组人血管内皮抑素组及重组人血管内皮抑素+顺铂组，连续给药2周。1周后检测肿瘤组织中VEGF-C、VEGF-D、VEGFR-3的表达水平和微淋巴管密度。免疫荧光染色诊断和计数循环肿瘤细胞。

结果

重组人血管内皮抑素组与重组人血管内皮抑素联合顺铂组的表达阳性率、微淋巴管密度均明显低于空白对照组与顺铂组（P < 0.05）；较高浓度的重组人血管内皮抑素联合顺铂组与重组人血管内皮抑素组表达阳性率和微淋巴管密度低于相应较低重组人血管内皮抑素浓度的组别（P < 0.05）。各组微淋巴管密度与VEGF-C、VEGF-D、VEGFR-3表达阳性率存在正相关。重组人血管内皮抑素联合顺铂各组的循环肿瘤细胞数目明显低于单独使用顺铂或重组人血管内皮抑素（P < 0.05）。

结论

重组人血管内皮抑素可以抑制肿瘤新生淋巴管生成，减少循环肿瘤细胞，作用大小与浓度有关。与顺铂联合使用能够更有效的减少循环肿瘤细胞。

Pazopanib diminishes non-small cell lung cancer (NSCLC) growth and metastases in vivo

Background

Anti-angiogenesis has been demonstrated to have a critical role in lung cancer pathogenesis. Here, we characterized the effect of the small-molecule angiogenesis inhibitor pazopanib on non-small cell lung cancer (NSCLC) cells.

Methods

NSCLC cells were tested for viability and migration after incubation with varying concentrations of pazopanib. Further, the phosphorylation status of extracellular signal-regulated kinase, protein kinase B, and MEK were assessed in vitro. For in vivo testing, mice grafted with NSCLC cell lines L9981 and A549 were treated orally with pazopanib.

Results

Pazopanib inhibits signaling pathways in tumor cells, thus blocking NSCLC cell growth and migration in vitro and inducing tumor cell arrest at G0/G1 phase. We show that pazopanib could inhibit tumor cell growth, decrease metastases, and prolong survival in two mouse xenograft models of human NSCLC.

Conclusion

These preclinical studies of pazopanib show the possibility of clinical application and, ultimately, improvement in patient outcome.

Inhibition of FAK and VEGFR-3 binding decreases tumorigenicity in neuroblastoma

Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for over 15% of pediatric cancer deaths. Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that is important in many facets of tumor development and progression. Vascular endothelial growth factor receptor-3 (VEGFR-3), another tyrosine kinase, has also been found to be important in the development of many human tumors including neuroblastoma. Recent reports have found that FAK and VEGFR-3 interact, and we have previously shown that both of these kinases interact in neuroblastoma. We have hypothesized that interruption of the FAK-VEGFR-3 interaction would lead to decreased neuroblastoma cell survival. In the current study, we examined the effects of a small molecule, chloropyramine hydrochloride (C4), designed to disrupt the FAK-VEGFR-3 interaction, upon cellular attachment, migration, and survival in two human neuroblastoma cell lines. We also utilized a murine xenograft model to study the impact of C4 upon tumor growth. In these studies, we showed that disruption of the FAK-VEGFR-3 interaction led to decreased cellular attachment, migration, and survival in vitro. In addition, treatment of murine xenografts with chloropyramine hydrochloride decreased neuroblastoma xenograft growth. Further, this molecule acted synergistically with standard chemotherapy to further decrease neuroblastoma xenograft growth. The findings from this current study help to further our understanding of the regulation of neuroblastoma tumorigenesis, and may provide novel therapeutic strategies and targets for neuroblastoma and other solid tumors of childhood.

Radiation-induced VEGF-C expression and endothelial cell proliferation in lung cancer

BACKGROUND

The present study was undertaken to investigate whether radiation induces the expression of vascular endothelial growth factor C (VEGF-C) through activation of the PI3K/Akt/mTOR pathway,subsequently affecting endothelial cells.

MATERIALS AND METHODS

Radiotherapy-induced tumor micro-lymphatic vessel density (MLVD) was determined in a lung cancer xenograft model established in SCID mice. The protein expression and phosphorylation of members of the PI3K/Akt/mTOR pathway and VEGF-C secretion and mRNA expression in irradiated lung cancer cells were assessed by Western blot analysis, enzyme-linked immunosorbent assays (ELISAs), and reverse transcriptase-polymerase chain reaction (RT-PCR). Moreover, specific chemical inhibitors were used to evaluate the role of the PI3K/Akt/mTOR signaling pathway. Conditioned medium (CM) from irradiated control-siRNA or VEGF-C-siRNA-expressing A549 cells was used to evaluate the proliferation of endothelial cells by the MTT assay.

RESULTS

Radiation increased VEGF-C expression in a dose-dependent manner over time at the protein but not at the mRNA level. Radiation also up-regulated the phosphorylation of Akt, mTOR, 4EBP, and eIF4E, but not of p70S6K. Radiation-induced VEGF-C expression was down-regulated by LY294002 and rapamycin (both p < 0.05). Furthermore, CM from irradiated A549 cells enhanced human umbilical vein endothelial cell (HUVEC) and lymphatic endothelial cell (LEC) proliferation, which was not observed with CM from irradiated VEGF-C-siRNA-expressing A549 cells.

CONCLUSIONS

Radiation-induced activation of the PI3K/Akt/mTOR signaling pathway increases VEGF-C expression in lung cancer cells, thereby promoting endothelial cell proliferation.

Associations of nm23H1, VEGF-C, and VEGF-3 receptor in human prostate cancer

We studied the expression of the non-metastatic clone 23 type 1 (nm23H1) gene, vascular endothelial growth factor (VEGF)-C, and its receptor VEGFR-3 using an in situ hybridization technique and immunohistochemical analyses with prostate cancer tissues and adjacent benign tissues of 52 human archival cases. The association between VEGF-C expression, microlymphatic count (MLC), and staining intensity for nm23H1 and VEGFR-3 was used to evaluate tumor metastasis and survival rate. MLC values were significantly higher in tumorous tissue than in non-cancerous tissue. VEGF-C mRNA, VEGFR-3, and nm23H1 were highly expressed in tumorous tissue. VEGFR-3 expression was greater in VEGF-C mRNA-positive tumors than in VEGF-C mRNA-negative tumors. The association of VEGFR-3 expression with VEGF-C mRNA and MLC suggested that the poor prognosis and tumor metastasis associated with VEGFR-3 expression may be due, in part, to its role in promoting angiogenesis. VEGF-C expression was significantly associated with tumor lymphangiogenesis, angiogenesis, and immune response as a potent multifunctional stimulating factor in prostate cancer. Expression of nm23H1 was significantly inversely correlated with lymph node metastasis. Furthermore, there was a strong negative correlation between the expression of nm23H1, VEGF-C mRNA, and MLC. These findings provide important information for prophylactic, diagnostic, and therapeutic strategies for prostate cancer.

Inhibition of the focal adhesion kinase and vascular endothelial growth factor receptor-3 interaction leads to decreased survival in human neuroblastoma cell lines

Neuroblastoma continues to be a devastating childhood solid tumor and is responsible for over 15% of all childhood cancer-related deaths. Focal adhesion kinase (FAK) and vascular endothelial growth factor receptor-3 (VEGFR-3) are protein tyrosine kinases that are overexpressed in a number of human cancers, including neuroblastoma. These two kinases can directly interact and provide survival signals to cancer cells. In this study, we utilized siRNA to VEGFR-3 to demonstrate the biologic importance of this kinase in neuroblastoma cell survival. We also used confocal microscopy and immunoprecipitation to show that FAK and VEGFR-3 bind in neuroblastoma. Finally, employing a 12-amino-acid peptide (AV3) specific to VEGFR-3, we showed that the colocalization between FAK and VEGFR-3 could be disrupted, and that disruption resulted in decreased neuroblastoma cell survival. These studies provide insight to the FAK-VEGFR-3 interaction in neuroblastoma and demonstrate its importance in this tumor type. Focusing upon the FAK-VEGFR-3 interaction may provide a novel therapeutic target for the development of new strategies for treatment of neuroblastoma.

[Lymphatic extension and lymphangiogenesis in non-small cell lung cancer]

Lymph node metastasis is a major adverse prognostic factor of malignant tumors, including non-small cell lung carcinoma (NSCLC). However the characterization of tumor associated lymphatic vessels and lymphangiogenic mediators in NSCLC are recent and their prognostic role is debated. Lymphatic vascular invasion (LVI) appears like a robust adverse prognostic factor when reported in NSCLC. This parameter should be better standardized and could be of use in adjuvant therapy indications. Moreover, anti-lymphangiogenesis therapies are currently under investigation and may become part of the anti-cancer strategy.

Evaluation of VEGF-C and tumor markers in bronchoalveolar lavage fluid for lung cancer diagnosis

A total of 87 patients were enrolled and bronchoalveolar lavage fluid (BALF) samples were obtained from all subjects. A significant difference was found in BALF VEGF-C level between patients with squamous cell carcinoma and benign diseases (P = 0.043). In addition, the concentration of NSE in BALF form the malignant group was significantly higher compared with that of the benign groups (P = 0.018). However, no statistical difference was observed in BALF CEA (P = 0.375) or CYFRA21-1 (P = 0.838) between lung cancer patients and nonmalignant controls. With a cut-off value of 2.06 ng/ml, NSE had a sensitivity of 72.9%, a specificity of 69.2%, respectively, in predicting the malignant nature of pulmonary mass. Our study observed that the level of VEGF-C was increased in BALF of patients with squamous cell carcinoma. Moreover, we found that NSE was significantly higher in BALF of lung cancer patients than in benign diseases.

A gene signature combining the tissue expression of three angiogenic factors is a prognostic marker in early-stage non-small cell lung cancer

BACKGROUND

Angiogenesis and lymphangiogenesis are key mechanisms for tumor growth and dissemination. They are mainly regulated by the vascular endothelial growth factor (VEGF) family of ligands and receptors. The aim of this study was to analyze relative expression levels of angiogenic markers in resectable non-small cell lung cancer patients in order to asses a prognostic signature that could improve characterization of patients with worse clinical outcomes.

METHODS

RNA was obtained from tumor and normal lung specimens from 175 patients. Quantitative polymerase chain reaction was performed to analyze the relative expression of HIF1A, PlGF, VEGFA, VEGFA165b, VEGFB, VEGFC, VEGFD, VEGFR1, VEGFR2, VEGFR3, NRP1 and NRP2.

RESULTS

Univariate analysis showed that tumor size and ECOG-PS are prognostic factors for time to progression (TTP) and overall survival (OS). This analysis in the case of angiogenic factors also revealed that PlGF, VEGFA, VEGFB and VEGFD distinguish patients with different outcomes. Taking into account the complex interplay between the different ligands of the VEGF family and to more precisely predict the outcome of the patients, we considered a new analysis combining several VEGF ligands. In order to find independent prognostic variables, we performed a multivariate Cox analysis, which showed that the subgroup of patients with higher relative expression of VEGFA plus lower VEGFB and VEGFD presented the poorest outcome for both TTP and OS.

CONCLUSIONS

The relative expression of these three genes can be considered as an angiogenic gene signature whose applicability for the selection of candidates for targeted therapies needs to be further validated.

Morphometry analysis of lymphatics in pulmonary adenocarcinomas with a lepidic growth pattern

Lymph vessels play an important role in tumor progression. Pulmonary adenocarcinomas, accounting for half of non-small-cell lung carcinomas, compose a spectrum of histological types, exclusively or without a lepidic growth pattern (LGP) along preserved interalveolar septa. In that context, this study was designed to investigate the lymphatic vascular pattern associated with LGP and the concomitant invasive component of pulmonary adenocarcinomas. Using the D2-40 monoclonal antibody as a marker of lymphatic endothelial cells, the lymphatic vessel density (LVD) and vessel-area fraction (LVAF) were morphometrically analyzed in four adenocarcinomas in situ (AIS) and the LGP of eight invasive adenocarcinomas (LPIA), and compared with their invasive pattern (IPIA). LVD in AIS (2.1 ± 0.7 mm(-2)) and LPIA (2.4 ± 1 mm(-2)) were significantly lower than that in IPIA (14.9 ± 13.6 mm(-2)) (p=0.001). Moreover, the lymphatic vascular pattern in LGP was similar to that of normal lung, with isolated small lymphatic vessels within the interalveolar septa. Our results showing the scarcity of lymphatics in LGP suggest an absence of septal lymphangiogenesis associated with the LGP pattern in lung adenocarcinomas, which could explain, at least partially, the better prognosis observed in tumors with exclusive or predominant lepidic spread compared with other subtypes.

Cell survival signaling in neuroblastoma

Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for over 15% of pediatric cancer deaths. Neuroblastoma tumorigenesis and malignant transformation is driven by overexpression and dominance of cell survival pathways and a lack of normal cellular senescence or apoptosis. Therefore, manipulation of cell survival pathways may decrease the malignant potential of these tumors and provide avenues for the development of novel therapeutics. This review focuses on several facets of cell survival pathways including protein kinases (PI3K, AKT, ALK, and FAK), transcription factors (NF-κB, MYCN and p53), and growth factors (IGF, EGF, PDGF, and VEGF). Modulation of each of these factors decreases the growth or otherwise hinders the malignant potential of neuroblastoma, and many therapeutics targeting these pathways are already in the clinical trial phase of development. Continued research and discovery of effective modulators of these pathways will revolutionize the treatment of neuroblastoma.

Endobronchial ultrasound doppler image features correlate with mRNA expression of HIF1-α and VEGF-C in patients with non-small-cell lung cancer

INTRODUCTION

We attempted to assess the correlation between the Doppler mode image patterns during endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration and the expression of angiogenesis-related molecules within lymph nodes in patients with non-small-cell lung cancer.

METHODS

Thirty-eight archived EBUS- transbronchial needle aspiration samples of lymph nodes (27 metastatic and 11 nonmetastatic) in patients with non-small-cell lung cancer with Doppler mode ultrasound image were analyzed. The Doppler mode image of the vasculature of the targeted lymph node was categorized into the following groups: normal blood flow, low blood flow (LBF), and high blood flow (HBF). Vascular index ratio (vascular area/lymph node area) of each metastatic lymph node was calculated. Total RNA and protein was extracted and analyzed for expression of HIF-1α, VEGF-A, and VEGF-C by quantitative RT-PCR and enzyme-linked immunosorbent assay.

RESULTS

Within the 27 metastatic lymph nodes, eight were categorized into the LBF group and 19 into the HBF group. Vascular index ratio was significantly higher in HBF than LBF (p = 0.0003). mRNA expression of HIF-1α and VEGF-A was significantly higher in metastatic lymph nodes than in benign lymph nodes (p < 0.0001). Compared with LBF and HBF, HIF-1α mRNA expression was significantly higher in LBF (p = 0.01) and VEGF-C mRNA expression was significantly higher in HBF (p = 0.0315). There was no significant difference in protein expression by enzyme-linked immunosorbent assay analysis.

CONCLUSIONS

The vascularity of metastatic lymph nodes observed by EBUS correlates with the mRNA expression of HIF-1α and VEGF-C (not VEGF-A). This correlation is a clinical utility that needs to be evaluated further.

[Prognostic value of lymphangiogenesis and lymphatic vessel invasion in non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

Studies have shown that tumor metastasis in a variety of tumors is associated with lymphangiogenesis and lymphatic vessel invasion (LVI). Tumor metastasis is an important factor that affects the prognosis of patients. The aim of this study is to determine the prognostic value of lymphangiogenesis and LVI in non-small cell lung cancer (NSCLC).

METHODS

We marked the endothelial cells of lymph vessels in lymphangiogenesis with specific monoclonal antibody D2-40. Immunohistochemistry was used to detect the expression of lymphangiogenesis and LVI in 79 cases of stage I-III NSCLC.

RESULTS

The intratumoral lymphatic vessel density (ITLVD) was significantly higher in patients with N2 disease than those with N0 disease (P=0.015). The ITLVD was significantly higher in patients with LVI+ than that in those with LVI- (P = 0.009). The ITLVD was also remarkably higher in poorly differentiated tumors than that in highly differentiated ones (P = 0.007). The ITLVD was remarkably higher in adenocarcinoma than that in squamous cell carcinomas (P = 0.025). Kaplan-Meier revealed that the survival rates of patients with higher ITLVD were remarkably poorer than those with lower ITLVD (P = 0.007). Thus, the ITLVD is an important prognostic factor of NSCLC. The peritumoral lymphatic vessel density is not correlated with the prognosis.

CONCLUSIONS

The ITLVD level is an important prognostic factor of NSCLC.

Autophagy control by the VEGF-C/NRP-2 axis in cancer and its implication for treatment resistance

A major contributor to cancer mortality is recurrence and subsequent metastatic transformation following therapeutic intervention. Therefore, in order to develop new treatment modalities and improve the efficacy of current ones, it is important to understand the molecular mechanisms that promote resistance to therapy in cancer cells. One pathway contributing to therapy resistance is autophagy, a self-digestive process that can eliminate unnecessary or damaged organelles to protect cancer cells from death. We have found that the VEGF-C/NRP-2 axis is involved in the activation of autophagy, which helps cancer cell survival following treatment. Inhibition of mTOR complex 1 activity by this axis is the underlying mechanism for the activation of autophagy. Furthermore, we identified two VEGF-C/NRP-2-regulated genes, LAMP-2 and WDFY-1, that have previously been suggested to participate in autophagy and vesicular trafficking. Upregulation of WDFY-1 following VEGF-C or NRP-2 depletion contributes to cytotoxic drug-mediated cell death. Together, these data suggest a link between the VEGF-C/NRP-2 axis and cancer cell survival despite the presence of chemotherapy-induced stress. Effective targeting of this pathway may lead to the development of new cancer therapies.

The extra domain A of fibronectin increases VEGF-C expression in colorectal carcinoma involving the PI3K/AKT signaling pathway

The extra domain A (EDA)-containing fibronectin (EDA-FN), an alternatively spliced form of the extracellular matrix protein fibronectin, is predominantly expressed in various malignancies but not in normal tissues. In the present study, we investigated the potential pro-lymphangiogenesis effects of extra domain A (EDA)-mediated vascular endothelial growth factor-C (VEGF-C) secretion in colorectal carcinoma (CRC). We detected the expressions of EDA and VEGF-C in 52 human colorectal tumor tissues and their surrounding mucosae by immunohistochemical analysis, and further tested the correlation between the expressions of these two proteins in aforementioned CRC tissues. Both EDA and VEGF-C were abundantly expressed in the specimens of human CRC tissues. And VEGF-C was associated with increased expression of EDA in human CRC according to linear regression analysis. Besides, EDA expression was significantly correlated with lymph node metastasis, tumor differentiation and clinical stage by clinicopathological analysis of tissue microarrays containing tumor tissues of 115 CRC patients. Then, human CRC cell SW480 was transfected with lentivectors to elicit expression of shRNA against EDA (shRNA-EDA), and SW620 was transfected with a lentiviral vector to overexpress EDA (pGC-FU-EDA), respectively. We confirmed that VEGF-C was upregulated in EDA-overexpressed cells, and downregulated in shRNA-EDA cells. Moreover, a PI3K-dependent signaling pathway was found to be involved in EDA-mediated VEGF-C secretion. The in vivo result demonstrated that EDA could promote tumor growth and tumor-induced lymphangiogenesis in mouse xenograft models. Our findings provide evidence that EDA could play a role in tumor-induced lymphangiogenesis via upregulating autocrine secretion of VEGF-C in colorectal cancer, which is associated with the PI3K/Akt-dependent pathway.

[Expression and prognostic value of VEGF-C and lymphangeogenesis in lung adenocarcinoma and squamous cell carcinoma]

BACKGROUND AND OBJECTIVE

Vascular endothelial growth factor-C (VEGF-C), a member of the VEGF family, has been proven to be a relatively special VEGF. When binding to its receptor VEGFR-3, it activates lymphangiogenesis, which likely induces lymph node metastasis in tumors. The aim of this study is to characterize the expression and prognostic value of VEGF-C and lymphangiogenesis in lung adenocarcinoma and squamous cell carcinoma.

METHODS

Through immunohistochemistry, the lymph vessel endothelial cells undergoing lymphangiogenesis were stained with podoplanin to detect the expression of VEGF-C and lymphangiogenesis in 98 cases with stage IIIa (N2) lung adenocarcinoma and squamous cell carcinoma.

RESULTS

The expression rate of the VEGF-C was positively correlated with the lymphatic microvessel density (LMVD; r=0.783, P<0.01). The LMVD was remarkably higher in VEGF-C positive expression group than that in the VEGF-C negative expression group. The expression rate of VEGF-C and lymphangiogenesis in lung adenocarcinoma was significantly higher than that in lung squamous cell carcinoma (P<0.01). Kaplan-Meier analysis showed that the survival rates in patients with positive VEGF-C expression were significantly lower than those in patients with negative VEGF-C expression (P<0.05).

CONCLUSIONS

Lymphangiogenesis rates are significantly higher in lung adenocarcinoma than that in squamous cell carcinoma. VEGF-C expression is an independent prognostic factor of stage IIIa (N2) lung adenocarcinoma and squamous cell carcinoma.

Endothelial cell Bcl-2 and lymph node metastasis in patients with oral squamous cell carcinoma

BACKGROUND

Loco-regional spread of disease causes high morbidity and is associated with the poor prognosis of malignant oral tumors. Better understanding of mechanisms underlying the establishment of lymph node metastasis is necessary for the development of more effective therapies for patients with oral cancer. The aims of this work were to evaluate a possible correlation between endothelial cell Bcl-2 and lymph node metastasis in patients with oral squamous cell carcinoma (OSCC), and to study signaling pathways that regulate Bcl-2 expression in lymphatic endothelial cells.

METHODS

Endothelial cells were selectively retrieved from paraffin-embedded tissue sections of primary human OSCC from patients with or without lymph node metastasis by laser capture microdissection. RT-PCR was used to evaluate Bcl-2 expression in tumor-associated endothelial cells and in tumor cells. In vitro, mechanistic studies were performed to examine the effect of vascular endothelial growth factor (VEGF)-C on the expression of Bcl-2 in primary human lymphatic endothelial cells.

RESULTS

We observed that Bcl-2 expression is upregulated in the endothelial cells of human oral tumors with lymph node metastasis as compared to endothelial cells from stage-matched tumors without metastasis. VEGF-C induced Bcl-2 expression in lymphatic endothelial cells via VEGFR-3 and PI3k/Akt signaling. Notably, OSCC cells express VEGF-C and induce Bcl-2 in lymphatic endothelial cells.

CONCLUSIONS

Collectively, this work unveiled a mechanism for the induction of Bcl-2 in lymphatic endothelial cells and suggested that endothelial cell Bcl-2 contributes to lymph node metastasis in patients with oral squamous cell carcinoma.

Polysaccharide of Cordyceps sinensis enhances cisplatin cytotoxicity in non-small cell lung cancer H157 cell line

BACKGROUND AND OBJECTIVE

The extracts of Cordyceps sinensis (Berk) Sacc (CS) have been used as a traditional medicine for centuries. However, few studies have examined the adjuvant action of CS in the treatment of non-small cell lung cancer (NSCLC). So the aim of this study is to investigate the adjuvant role of CS in the treatment of NSCLC.

METHODOLOGY

The effects of the combination treatment of the polysaccharide-rich fraction of CS and cisplatin on H157 NSCLC cells were investigated through MTT assay for cell viability, lactate dehydrogenase and fluorescein diacetate and propidium iodide assay for cytotoxicity, and with flow cytometric analysis for apoptosis. The expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in H157 cells were detected by immunohistochemistry.

RESULTS

Compared with the cells treated with cisplatin alone, cell viability was significantly decreased and the expression levels of VEGF and bFGF protein were significantly reduced in the cells treated with a combination of CS and cisplatin.

CONCLUSION

The current study indicates that the polysaccharide of CS inhibits tumor growth in NSCLC and that CS may be a potential adjuvant chemotherapeutic agent in NSCLC therapy.

Increased expression of vascular endothelial growth factor-C and nuclear CXCR4 in hepatocellular carcinoma is correlated with lymph node metastasis and poor outcome

PURPOSE

Lymph node metastasis (LNM) is a chief cause of morbidity and mortality in patients with hepatocellular carcinoma (HCC) after hepatectomy. The aim of this study was to investigate the relationship between the expression of CXCR4 and vascular endothelial cell growth factor (VEGF)-C and the clinicopathological features of HCC with LNM.

METHODS

Immunohistochemical staining for CXCR4 and VEGF-C was performed on tissue microarrays that were constructed using tumor specimens from patients with HCC with (N = 123) or without (N = 145) LNM. The relationship between the clinicopathological features of HCC and the expression of CXCR4 and VEGF-C was analyzed using the Pearson chi(2) test, logistical regression analysis, and receiver operating characteristic analysis.

RESULTS

Nuclear CXCR4 expression and VEGF-C expression were positively correlated with LNM and poor outcome in HCC. Moreover, nuclear CXCR4 expression was positively correlated with VEGF-C expression (correlation coefficient 0.256). Receiver operating characteristic analysis revealed that both factors were predictive of HCC LNM {CXCR4: area under the curve, 0.695 [95% confidence interval (CI), 0.630-0.759; VEGF-C: area under the curve, 0.629 (95% CI, 0.562-0.695]}. Patients with tumors exhibiting high nuclear CXCR4 expression or high VEGF-C expression had significantly poorer overall survival than those with low tumor expression of the corresponding factors. Multivariate analysis showed that UICC T stage [odds ratio (OR), 1.615, 95% CI, 1.306-1.997], nuclear CXCR4 expression (OR, 3.998; 95% CI, 2.706-5.907), and VEGF-C expression (OR, 1.903; 95% CI, 1.203-3.011) were independent risk factors for developing HCC LNM.

DISCUSSION

These findings suggest that nuclear CXCR4 expression and VEGF-C expression can be used to identify patients with HCC at high risk for developing LNM.

Role of interleukin-17 in lymphangiogenesis in non-small-cell lung cancer: Enhanced production of vascular endothelial growth factor C in non-small-cell lung carcinoma cells

Interleukin-17 (IL-17), a potent pro-inflammatory cytokine, plays an active role in inflammation and cancer. Recently, we found that increased IL-17-producing cells correlate with poor survival and increased lymphangiogenesis in non-small-cell lung cancer (NSCLC), but the mechanism is unknown. Here, we show that IL-17 promotes lymphangiogenesis via inducing vascular endothelial growth factor-C (VEGF-C) production by lung cancer cells. We found that IL-17 receptor (IL-17R) is expressed on the surface of Lewis lung carcinoma (LLC) cells but not on lymphatic endothelial cells (LEC). Moreover, LEC chemotaxis and tube formation (measures of net lymphangiogenic potential) were increased by conditioned medium from recombinant mouse IL-17 (rmIL-17)-stimulated LLC but not by rmIL-17. Interleukin-17 increased production of VEGF-C in lung cancer cell lines. The enhanced chemotaxis and endothelial cord formation in the presence of LLC/rmIL-17 was inhibited by addition of recombinant mouse VEGF R3/Fc chimera. Treatment of the A549 cells with rIL-17 significantly increased VEGF-C expression, which was extracellular signal-regulated protein kinase 1/2 (ERK 1/2) dependent. Importantly, we found significant correlations between IL-17 expression, VEGF-C expression and lymphatic vascular density (LVD) in NSCLC. We conclude that IL-17 is involved in lymphangiogenesis in NSCLC by enhancing production of VEGF-C, and IL-17 may be an important target for the treatment of NSCLC.

High VEGFC expression is associated with unique gene expression profiles and predicts adverse prognosis in pediatric and adult acute myeloid leukemia

High VEGFC mRNA expression of acute myeloid leukemia (AML) blasts is related to increased in vitro and in vivo drug resistance. Prognostic significance of VEGFC on long-term outcome and its associated gene expression profiles remain to be defined. We studied effect of VEGFC on treatment outcome and investigated gene expression profiles associated with VEGFC using microarray data of 525 adult and 100 pediatric patients with AML. High VEGFC expression appeared strongly associated with reduced complete remission rate (P = .004), reduced overall and event-free survival (OS and EFS) in adult AML (P = .002 and P < .001, respectively). Multivariable analysis established high VEGFC as prognostic indicator independent of cytogenetic risk, FLT3-ITD, NPM1, CEBPA, age, and white blood cell count (P = .038 for OS; P = .006 for EFS). Also, in pediatric AML high VEGFC was related to reduced OS (P = .041). A unique series of differentially expressed genes was identified that distinguished AML with high VEGFC from AML with low VEGFC, that is, 331 up-regulated genes (representative of proliferation, vascular endothelial growth factor receptor activity, signal transduction) and 44 down-regulated genes (eg, related to apoptosis) consistent with a role in enhanced chemoresistance. In conclusion, high VEGFC predicts adverse long-term prognosis and provides prognostic information in addition to well-known prognostic factors.

Vascular endothelial growth factor receptors VEGFR-2 and VEGFR-3 are localized primarily to the vasculature in human primary solid cancers

PURPOSE

Vascular endothelial growth factor (VEGF) signaling is key to tumor angiogenesis and is an important target in the development of anticancer drugs. However, VEGF receptor (VEGFR) expression in human cancers, particularly the relative expression of VEGFR-2 and VEGFR-3 in tumor vasculature versus tumor cells, is poorly defined.

EXPERIMENTAL DESIGN

VEGFR-2- and VEGFR-3-specific antibodies were identified and used in the immunohistochemical analysis of human primary cancers and normal tissue. The relative vascular localization of both receptors in colorectal and breast cancers was determined by coimmunofluorescence with vascular markers.

RESULTS

VEGFR-2 and VEGFR-3 were expressed on vascular endothelium but not on malignant cells in 13 common human solid tumor types (n > 400, bladder, breast, colorectal, head and neck, liver, lung, skin, ovarian, pancreatic, prostate, renal, stomach, and thyroid). The signal intensity of both receptors was significantly greater in vessels associated with malignant colorectal, lung, and breast than adjacent nontumor tissue. In colorectal cancers, VEGFR-2 was expressed on both intratumoral blood and lymphatic vessels, whereas VEGFR-3 was found predominantly on lymphatic vessels. In breast cancers, both receptors were localized to and upregulated on blood vessels.

CONCLUSIONS

VEGFR-2 and VEGFR-3 are primarily localized to, and significantly upregulated on, tumor vasculature (blood and/or lymphatic) supporting the majority of solid cancers. The primary clinical mechanism of action of VEGF signaling inhibitors is likely to be through the targeting of tumor vessels rather than tumor cells. The upregulation of VEGFR-3 on tumor blood vessels indicates a potential additional antiangiogenic effect for dual VEGFR-2/VEGFR-3-targeted therapy.

Advances in the research on lymphangiogenesis in carcinoma tissues (Review)

Metastatic spread of tumors is an important prognostic factor for cancer patients. The effect of angiogenesis on cancer cell proliferation and metastatic spread has been confirmed. However, less attention has been focused on research involving tumor lymphangiogenesis as opposed to research on tumor angiogenesis, due to the lack of specific markers for lymphatic vessel endothelial cells (LVECs). Recently, the improvement of isolation techniques for LVECs and the discovery of specific LVEC markers such as vascular endothelial growth factor receptor-3 (VEGFR-3), podoplanin, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and Prox1 have led to advances in research involving lymphangiogenesis in carcinoma tissues. New lymphatic vessels in tumor tissues may originate from bone marrow endothelial progenitor cells, directly from the preexisting lymphatic vessels, and even by cell transformation. Peritumoral lymphatic vessels play a more important role in the process of tumor metastasis by providing more channels for lymphatic invasion and metastatic spread. The molecular mechanism of tumor lymphangiogenesis is complicated, and numerous factors such as VEGF-A, platelet-derived growth factors (PDGFs), hepatocyte growth factor (HGF), fibroblast growth factor-2 (FGF-2), and angiopoietins (Ang) are directly or indirectly involved in the process. However, it has been demonstrated that the VEGF-C/VEGF-D/VEGFR-3 signaling pathways are the most important mechanism underlying tumor lymphangiogenesis.

Role of vascular endothelial growth factor receptor-3/Flt-4 in early-stage cervical cancer

The present study was designed to investigate the role of vascular endothelial growth factor receptor (VEGFR)-3/Flt-4 in the early stages of cervical cancer. VEGFR-3/Flt-4 expression, vascular endothelial growth factor (VEGF)-C and VEGF-D in the early stages (Ia-IIa) of cervical cancer in 41 patients was examined by immunohistochemical analysis. Additionally, the VEGFR-3/Flt-4-marked vascular density (MVD) was examined and the relationship of these factors with clinicopathological factors was analyzed. VEGFR-3/Flt-4 was found to be expressed in lymphatic endothelial cells and, to a certain extent, in vascular endothelial cells. The VEGFR-3/Flt-4-positive vessels were largely distributed in the stroma surrounding the tumor tissues, and these vessels were morphologically divided into blood and lymphatic vessels, respectively. Cancer cells were found to express VEGF-C, VEGF-D and VEGFR-3/Flt-4, and their positive expression rate was 48.7% (20/41), 58.5% (24/41) and 63.4% (26/41), respectively. VEGFR-3/Flt-4 expression in the cancer cells of the cervical cancer patients in our study was found to be correlated to the clinical stage, lymph node metastasis, lymphatic invasion and expression of VEGF-C and VEGF-D. However, this expression was unrelated to menstrual status, histological grade and histological classification. MVD was correlated to the clinical stage and expression of VEGF-C and VEGF-D, but was unrelated to menstrual status, histological grade, histological classification, lymph node metastasis and lymphatic invasion. In conclusion, VEGFR-3/Flt-4 plays an important role in the early stages of cervical cancer.

Association between lymphangiogenesis-/micrometastasis- and adhesion-related molecules in resected stage I NSCLC

BACKGROUND

The purpose of this study was to clarify the role and clinical significance of lymphangiogenesis/micrometastases and adhesion molecules in resected stage I non-small cell lung cancer (NSCLC).

METHODS

Immunohistochemical (IHC) staining was used to analyze the protein expression of vascular endothelial growth factor-C (VEGF-C), VEGF, E-cadherin, alpha-catenin, beta-catenin, and gamma-catenin in paraffin-embedded tumor samples from 117 well-characterized stage I NSCLC patients and to compare the protein expression, clinical variables and survival outcome. As a micrometastatic parameter in lymph nodes (LNs), cytokeratin (CK) staining was performed.

RESULTS

The positive expression of VEGF-C and VEGF were detected in 54 (48.7%) and 86 (73.5%), respectively. We identified micrometastatic tumor cells in pathological N0 LNs in 34 (29.1%) of 117 patients. E-cadherin, alpha-catenin, beta-catenin, and gamma-catenin were identified in 70 (59.8%), 41 (35.0%), 83 (70.9%), and 61 (52.1%) specimens, respectively. The VEGF-C expression was found more frequently in squamous cell carcinoma (SQ) and in the tumors with negative expression of beta-catenin than counter features. The VEGF expression was found more frequently in the tumors with a negative expression of E-cadherin. Micrometastasis was found more frequently in a pathological T2 status and in the tumors with a negative expression of alpha-catenin. Beta-catenin and gamma-catenin expressions were found less and more frequently in SQ, respectively. A univariate and multivariate survival analysis demonstrated that old age, pathological T2 status, and micrometastasis were independently associated with an increased risk of poor survival in the patients who underwent a surgical resection of stage I NSCLC.

CONCLUSIONS

Complicated relationships exist between lymphangiogenesis/micrometastases and adhesion molecules with a specific histology. The detection of lymph nodal micrometastasis by CK may therefore be a useful marker for predicting a poor prognosis in patients who undergo a complete resection of stage I NSCLC.

Vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), and thrombospondin-1 (TSP-1) expression in urothelial carcinomas

Angiogenesis is a multistep process that depends on the balance of proangiogenic factors and inhibitors as well as on interactions with the extracellular matrix. We examined the immunohistochemical expression of the defining angiogenic agents, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9), and the antiangiogenic agent thrombospondin-1 (TSP-1) in 131 patients with urothelial carcinoma and correlated their expression levels with clinicopathological parameters. VEGF and MMP-9 expression was higher in high-grade tumors than in low-grade tumors (p=0.000 and p=0.001, respectively), whereas the reverse was true for TSP-1 (p=0.000). VEGF and MMP-9 expression was higher in deeper tumors compared to superficial tumors and in invasive tumors compared to non-invasive tumors (p=0.001 and p=0.001, respectively), while TSP-1 was lower (p=0.000). We could differentiate 22 of 41 muscle-invasive (T2) cases as superficial (T2a; n=7) or deep (T2b; n=15), but no difference was found between them regarding VEGF, MMP-9, or TSP-1 expression (p=0.783, p=0.289, and p=0.783, respectively). There was a positive correlation between VEGF and MMP-9 expression (p=0.008, r=0.23) but a negative correlation between MMP-9 and TSP-1 expression (p=0.014, r=-0.21). Increased VEGF and MMP-9 expression as well as decreased TSP-1 expression may play considerable roles in the invasion and differentiation of urothelial carcinoma.

Vascular endothelial growth factor-C protects prostate cancer cells from oxidative stress by the activation of mammalian target of rapamycin complex-2 and AKT-1

Recurrence and subsequent metastatic transformation of cancer develops from a subset of malignant cells, which show the ability to resist stress and to adopt to a changing microenvironment. These tumor cells have distinctly different growth factor pathways and antiapoptotic responses compared with the vast majority of cancer cells. Long-term therapeutic success can only be achieved by identifying and targeting factors and signaling cascades that help these cells survive during stress. Both microarray and immunohistochemical analysis on human prostate cancer tissue samples have shown an increased expression of vascular endothelial growth factor-C (VEGF-C) in metastatic prostate cancer. We have discovered that VEGF-C acts directly on prostate cancer cells to protect them against oxidative stress. VEGF-C increased the survival of prostate cancer cells during hydrogen peroxide stress by the activation of AKT-1/protein kinase Balpha. This activation was mediated by mammalian target of rapamycin complex-2 and was not observed in the absence of oxidative stress. Finally, the transmembrane nontyrosine kinase receptor neuropilin-2 was found to be essential for the VEGF-C-mediated AKT-1 activation. Indeed, our findings suggest a novel and distinct function of VEGF-C in protecting cancer cells from stress-induced cell death, thereby facilitating cancer recurrence and metastasis. This is distinctly different from the known function of VEGF-C in inducing lymphangiogenesis.

IL-12 can target human lung adenocarcinoma cells and normal bronchial epithelial cells surrounding tumor lesions

Background

Non small cell lung cancer (NSCLC) is a leading cause of cancer death. We have shown previously that IL-12rb2 KO mice develop spontaneously lung adenocarcinomas or bronchioalveolar carcinomas.

Aim of the study was to investigate i) IL-12Rβ2 expression in human primary lung adenocarcinomas and in their counterparts, i.e. normal bronchial epithelial cells (NBEC), ii) the direct anti-tumor activity of IL-12 on lung adenocarcinoma cells in vitro and vivo, and the mechanisms involved, and iii) IL-12 activity on NBEC.

Methodology/Principal Findings

Stage I lung adenocarcinomas showed significantly (P = 0.012) higher frequency of IL-12Rβ2 expressing samples than stage II/III tumors. IL-12 treatment of IL-12R⁺ neoplastic cells isolated from primary adenocarcinoma (n = 6) inhibited angiogenesis in vitro through down-regulation of different pro-angiogenic genes (e.g. IL-6, VEGF-C, VEGF-D, and laminin-5), as assessed by chorioallantoic membrane (CAM) assay and PCR array. In order to perform in vivo studies, the Calu6 NSCLC cell line was transfected with the IL-12RB2 containing plasmid (Calu6/β2). Similar to that observed in primary tumors, IL-12 treatment of Calu6/β2⁺ cells inhibited angiogenesis in vitro. Tumors formed by Calu6/β2 cells in SCID/NOD mice, inoculated subcutaneously or orthotopically, were significantly smaller following IL-12 vs PBS treatment due to inhibition of angiogenesis, and of IL-6 and VEGF-C production. Explanted tumors were studied by histology, immuno-histochemistry and PCR array. NBEC cells were isolated and cultured from lung specimens of non neoplastic origin. NBEC expressed IL-12R and released constitutively tumor promoting cytokines (e.g. IL-6 and CCL2). Treatment of NBEC with IL-12 down-regulated production of these cytokines.

Conclusions

This study demonstrates that IL-12 inhibits directly the growth of human lung adenocarcinoma and targets the adjacent NBEC. These novel anti-tumor activities of IL-12 add to the well known immune-modulatory properties of the cytokine and may provide a rational basis for the development of a clinical trial.

Astrocytoma derived short-term cell cultures retain molecular signatures characteristic of the tumour in situ

The heterogeneity of tumours and uncertainties surrounding derived short-term cell cultures and established cell lines fundamentally challenge the research and understanding of tumour growth and development. When tumour cells are cultured, changes are inevitably induced due to the artificial growth conditions. Several recent studies have questioned how representative established cell lines or derived short-term cell cultures are of the tumour in situ. We have characterised gene expression changes induced by short-term culture in astrocytoma in order to determine whether derived short-term cell cultures are representative of the tumour in situ. In comparison to the majority of studies, paired biopsies and derived short-term cultures were investigated to reduce the effects of long-term culture and inter-tumour variability when comparing biopsies and derived cultures from tumours with the same histology from different individuals. We have used the Affymetrix GeneChip U133A to generate gene expression profiles of 6 paediatric pilocytic astrocytoma (PA) biopsies and derived short-term cell cultures and 3 adult glioblastoma multiforme (GBM) biopsies and derived short-term cultures. Significant differential gene expression is induced by short-term culture. However, when the biopsy and derived short-term cell culture samples were grouped according to tumour type (PA and GBM) a molecular signature of 608 genes showed significant differential expression between the groups. This gene cohort can distinguish PA and GBM tumours, regardless of the sample source, suggesting that astrocytoma derived short-term cultures do retain key aspects of the global tumour expression profile and are representative of the tumour in situ. Furthermore, these genes are involved in pathways and functions characteristic of adult GBM including VEGF signalling, hypoxia and TP53 signalling.