Circulating lymphangiogenic growth factors in gastrointestinal solid tumors, could they be of any clinical significance?

Dual pH- and temperature-responsive poly(dimethylaminoethyl methacrylate)-coated mesoporous silica nanoparticles as a smart drug delivery system

A robust drug delivery system was created by grafting poly(dimethylaminoethyl methacrylate) (PDMAEMA) onto silica nanoparticles with two different lengths using an in situ atom transfer radical polymerization, resulting in the formation of a pH- and temperature-sensitive shell. The high molecular weight PDMAEMA demonstrated effective controlled drug release, and prevented drug release in healthy cells. Drug release occurred through polymer shell protonation at pH 5. The critical temperature of 41 °C facilitated rapid solvation of the shell polymers in the blood, preventing tissue accumulation and reducing toxicity compared to systems with lower critical solution temperatures. Field-emission scanning electron microscopy analysis and nitrogen adsorption/desorption analysis showed that the nanoparticles have a fine network, mesoporous structure, and a mean size of around 17 nm that show their excellent capacity for loading drugs. Fourier-transform infrared spectroscopy showed that all the modification steps and polymerization were successfully implemented. Thermogravimetric analysis showed PDMAEMA chains with two different lengths grafted onto the nanoparticles. Transmission electron microscopy analysis also showed grafted polymer chains on the hybrid nanoparticles. The release profile of model cancer drugs (doxorubicin and methotrexate) varied with pH and temperature, with high molecular weight PDMAEMA shells effectively preventing drug release at neutral pH. In vitro analysis using the HeLa cell line showed minimal toxicity in blank samples and significant release profile in acidic environment.

Lymphangiogenesis and colorectal cancer

Lymphatic metastasis is an important event in the progress of metastasis in colorectal cancer (CRC). The purpose of this article is to assess the role of lymphangiogenesis on CRC. In peritumoral areas of CRC, the lymphatic microvessel density (LMVD) is higher than those in normal colorectal tissues. Morever, the high LMVD is correlated with DFS and local recurrence in CRC. The VEGF-C/VEGF-D/VEGFR-3 pathway, sonic hedgehog (Shh) signaling pathway and extracellular matrix (ECM) are involved in the regulation of lymphangiogenesis in CRC. Inhibition of the VEGF-C/VEGF-D/VEGFR-3 pathway by specific antibodies has been reported to efficiently inhibit experimental tumor lymphangiogenesis and metastasis in animal experiments. Although lymphangiogenesis has been reported to play an important role in the occurrence of colon cancer and to be associated with prognosis, it remains unclear whether it is a valid therapeutic target molecule. Further study of the potential of targeting this process for anti-lymphatic therapies is worthwhile.

Correlation between serum levels of vascular endothelial growth factor-C and sentinel lymph node status in early breast cancer

Axillary lymph nodes status is the most important prognosis factor in early breast cancer. This status is known by a selective sentinel lymph node biopsy (SLNB) and/or lymphadenectomy. Immunohistochemical studies of breast cancer tumour tissue have reported a relation between the increased expression of vascular endothelial growth factor-C (VEGF-C) and the risk of lymph node metastasis. We researched whether serum levels of VEGF-C could be a predictor factor of sentinel lymph node status in these patients. A prospective analysis was performed on serum from 174 patients with early breast cancer who underwent SLNB. The level of VEGF-C was determined by enzyme-linked immunosorbent assay. Clinical-pathologic variables were collected. Univariate analysis and multivariate logistic regression were conducted, taking SLNB positivity as the segmentation variable. The predictive value of VEGF-C was assessed using ROC curves. Of the sample group of 167 patients, 64 (38.3 %) had affected lymph node. Eighteen patients (28.1 %) presented micrometastasis; there were isolated tumour cells in 11 cases (17.2 %) and macrometastasis in 35 (54.6 %). The median value of VEGF-C was 6561.5 pg/ml. These values did not correlate with any clinical variables, and there was no association between the level of VEGF-C and SLNB status (p = 0.626). In the multivariate analysis, tumour size (p = 0.009) and the presence of vascular invasion (p < 0.001) were independently associated with sentinel lymph node affected. Serum levels of VEGF-C do not appear to predict sentinel lymph node status in patients with early breast cancer who undergo SLNB.

Cytokines association with clinical and pathological changes in esophageal squamous cell carcinoma

Carcinogenic transformation of cells in esophageal squamous cell carcinoma (ESCC) is characterized on molecular level by, among other things, changes in protein expression. Among all proteins related to inflammation, cytokines may be implicated as possible biological markers of esophageal cancer. These biomarkers, near imaging techniques, may be helpful in diagnosis and monitoring therapy in ESCC patients. This review demonstrates findings of researches on dysregulation of cytokines in ESCC and their clinical and pathological implications. Articles on cytokines were selected according to the following criteria: (i) the study was performed at protein level, (ii) the differences in cytokines expression or concentration were detected in tissues or serum from ESCC patients, (iii) the alterations of cytokines levels were detected by: immunohistochemistry (IHC), western blot (WB) and enzyme-linked immunosorbent assay (ELISA). Members of VEGF family seem to play an essential role as potential markers in ESCC. The results of all cytokines researches are promising but further studies are necessary to establish the biological significance of these peptydes in ESCC, their potential usefulness for early diagnosis, pre- and postoperative prognosis and monitoring of the respond to chemo- and radiotherapy of cancer patients.

Metastasis via Peritumoral Lymphatic Dilation in Oral Squamous Cell Carcinoma

PURPOSE

Nodal metastasis is the main prognostic factor in the patients with oral squamous cell carcinoma (OSCC). We investigated the association between tumor-associated lymphatics and OSCC characteristics.

METHODS

Thirty-four specimens were used for the immunohistochemical staining with the antibody for vascular endothelial growth factor (VEGF)-C, VEGF-D, VEGF receptor (VEGFR)-3, phosphorylated VEGFR-3, D2-40, and matrix metallproteinases (MMPs). We observed the distribution of the lymphangiogenic factors and quantified the degree of expression. We determined lymphatic vessel density (LVD) and lymphatic vessel dilatation with D2-40 immunostaining. We assessed the association of LVD or lymphatic vessel dilatation with tumor progression or tumor differentiation.

RESULTS

OSCC cells expressed lymphangiogenic ligands. Lymphangiogenic receptor, VEGFR-3, was expressed and activated in some tumor cells as well as in tumor-associated endothelial cells. LVD was not associated with tumor size or nodal status, but lymphatic vessel dilatation was higher in tumors with nodal metastasis, and also higher in poorly differentiated tumors. In stromal area of OSCC, MMP-1 and MMP-10 were up-regulated and the basement membrane of tumor-associated endothelial cells was destroyed by these collagenases.

CONCLUSION

In the primary tumors with nodal metastasis, especially in poorly differentiated OSCC, tumor cells invaded the dilated lymphatic vessels via ruptured sites. MMP-1 and MMP-10 are important in the lysis of the glycocalyx inside the tumor-associated lymphatic endothelial cells.

Prognostic value of vascular endothelial growth factor expression in resected gastric cancer

BACKGROUND AND AIMS

Vascular endothelial growth factor (VEGF) is a potential prognostic biomarker for patients with resected gastric cancer. However, its role remains controversial. The objective of this study was to conduct a systematic review and meta-analysis of published literature.

METHODS

Relevant literature was identified using Medline and survival data from published studies were collected following a methodological assessment. Quality assessment of eligible studies and meta-analysis of hazard ratio (HR) were performed to review the correlation of VEGF overexpression with survival and recurrence in patients with gastric cancer.

RESULTS

Our meta-analysis included 44 published studies with 4,794 resected patients. VEGF subtype for the prediction of overall survival (OS) included tissue VEGF (HR=2.13, 95% CI 1.71-2.65), circulating VEGF (HR=4.22, 95% CI 2.47-7.18), tissue VEGF-C (HR=2.21, 95% CI 1.58-3.09), tissue VEGF-D (HR=1.73, 95% CI 1.25-2.40). Subgroup analysis showed that HRs of tissue VEGF for OS were, 1.78 (95% CI 0.90-3.51) and 2.31 (95% CI 1.82-2.93) in non-Asians and Asians, respectively. The meta-analysis was also conducted for disease free survival (DFS) and disease specific survival (DSS).

CONCLUSION

Positive expression of tissue VEGF, circulating VEGF, VEGF-C and VEGF-D were all associated with poor prognosis in resected gastric cancer. However, VEGF demonstrated no significant prognostic value for non-Asian populations. Circulating VEGF may be better than tissue VEGF in predicting prognosis.

PI3Kα activates integrin α4β1 to establish a metastatic niche in lymph nodes

Lymph nodes are initial sites of tumor metastasis, yet whether the lymph node microenvironment actively promotes tumor metastasis remains unknown. We show here that VEGF-C/PI3Kα-driven remodeling of lymph nodes promotes tumor metastasis by activating integrin α4β1 on lymph node lymphatic endothelium. Activated integrin α4β1 promotes expansion of the lymphatic endothelium in lymph nodes and serves as an adhesive ligand that captures vascular cell adhesion molecule 1 (VCAM-1)(+) metastatic tumor cells, thereby promoting lymph node metastasis. Experimental induction of α4β1 expression in lymph nodes is sufficient to promote tumor cell adhesion to lymphatic endothelium and lymph node metastasis in vivo, whereas genetic or pharmacological blockade of integrin α4β1 or VCAM-1 inhibits it. As lymph node metastases accurately predict poor disease outcome, and integrin α4β1 is a biomarker of lymphatic endothelium in tumor-draining lymph nodes from animals and patients, these results indicate that targeting integrin α4β1 or VCAM to inhibit the interactions of tumor cells with the lymph node microenvironment may be an effective strategy to suppress tumor metastasis.

Decreased serum vascular endothelial growth factor-D levels in metastatic patients with differentiated thyroid carcinoma

OBJECTIVE

Vascular endothelial growth factor-D (VEGF-D) has been identified as one of the lymphangiogenic growth factors involved in metastatic diffusion. The aim of this study is to evaluate the serum VEGF-D levels in patients with differentiated thyroid cancer at different conditions of disease.

DESIGN AND PATIENTS

We studied prospectively the VEGF-D plasma levels in 96 subjects affected by differentiated thyroid cancer. The patients were divided into three groups according to the clinical and biochemical findings: patients with no evidence of disease (Cured), patients with pathological (>1 ng/ml) stimulated thyroglobulin (Tg) (Path-Tg/rhTSH) levels only after rhTSH and patients with elevated basal Tg levels (Path-Tg/LT4).

RESULTS

The serum VEGF-D concentrations in patients of group Cured were not different from the controls, while group Path-Tg/rhTSH showed baseline serum VEGF-D levels significantly lower than group Cured and controls (P < 0·001 and P < 0·01, respectively). Moreover, the patients of group Path-Tg/LT4 showed median serum cytokine concentrations at baseline not significantly different from the patients of group Path-Tg/rhTSH. The rhTSH stimulation did not modify the difference in serum VEGF-D levels in patients of group Cured and group Path-Tg/rhTSH.

CONCLUSIONS

Our data demonstrate that the VEGF-D serum levels are reduced in patients with metastases of differentiated thyroid cancer, regardless of the degree of metastatic spread. It is possible that some other molecule produced by the tumoral tissue could affect the VEGF-D physiologically produced of from different tissues, thus conducting to a decrease in the VEGF-D found in blood of patients with evidence of metastatic differentiated thyroid cancer.

Mucin 1 and vascular endothelial growth factor C expression correlates with lymph node metastatic recurrence in patients with N0 esophageal cancer after Ivor-Lewis esophagectomy

BACKGROUND

The purpose of the present study was to investigate the risk factors associated with lymph node metastatic recurrence in patients with N0 esophageal cancer after Ivor-Lewis esophagectomy based on the detection of Mucin 1 mRNA and vascular endothelial growth factor (VEGF) C mRNA.

METHODS

The subjects were 82 patients with pN0 esophageal cancer who underwent Ivor-Lewis esophagectomy with two-field lymph node dissection from January 2001 to January 2005. A total of 501 lymph nodes obtained from these patients were re-evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) to detect mucin l (MUC1) mRNA; VEGF-C mRNA was also detected in esophageal cancer issues by RT-PCR. The diagnosis of lymph node micrometastasis (LNMM) was based on the detection of MUC1 mRNA. The Kaplan-Meier method was used to calculate the survival rate and lymph nodal metastatic rate, the log-rank test was performed to compare the recurrence rate, and Cox regression multivariate analysis was performed to determine independent prognostic factors.

RESULTS

MUC1 mRNA was detected in 29 lymph nodes from 23 patients, which accounted for 5.79% of all the 501 lymph nodes and 28.05% of all 82 patients, respectively. Vascular endothelial growth factor C mRNA was identified in esophageal cancer issues from 42 (51.22%) patients. The overall 3- and 5-year survival rates of 82 patients were 78.0 and 51.2%, respectively. First recurrence exhibiting lymph nodal metastasis was recognized in 37 patients (45.1%) in the first 3 years after operation. The lymph node metastatic rate in patients in the first 3 years after operation was significantly associated with T status (p < 0.05) and the lymph node metastatic rate of the patients with LNMM was significantly higher than that of the patients without LNMM (p < 0.01). The lymph node metastatic rate of the patients with VEGF-C mRNA expression in esophageal cancer tissues was significantly higher than that of the patients without VEGF-C mRNA expression (p < 0.01).The results of multivariate analysis confirmed that VEGF-C mRNA expression in esophageal cancer tissues, LNMM, and T status in patients with N0 esophageal cancer were independent relevant factors for 3-year lymph node metastatic recurrence after Ivor-Lewis esophagectomy.

CONCLUSIONS

Vascular endothelial growth factor C mRNA expression in esophageal cancer tissues, LNMM, and T status in patients with N0 esophageal cancer were independent risk factors for 3-year lymph node metastatic recurrence after Ivor-Lewis esophagectomy. Adjunctive therapy might be beneficial in controlling the locoregional recurrence and elevated healing rates for certain patients.

Lymphangiogenesis: A new player in cancer progression

Lymph node metastasis is the hallmark of colon cancer progression, and is considered one of the most important prognostic factors. Recently, there has been growing evidence that tumor lymphangiogenesis (formation of new lymphatic vessels) plays an important role in this process. Here, we review the latest findings of the role of lymphangiogenesis in colorectal cancer progression, and discuss its clinical application as a biomarker and target for new therapy. Understanding the molecular pathways that regulate lymphangiogenesis is mandatory to pave the way for the development of new therapies for cancer. In the future, tailored treatments consisting of combinations of chemotherapy, other targeted therapies, and anti-lymphangiogenesis agents will hopefully improve patient outcomes. This progression to the clinic must be guided by new avenues of research, such as the identification of biomarkers that predict response to treatment.

Impact of the transfer of sFlt-1 gene fragments on the ERK1/2 pathway of VEGF in vitro

PURPOSE

To investigate whether various sFlt-1 gene fragments affect the biological functions and ERK1/2 pathway of vascular endothelial growth factor (VEGF) under conditions of hypoxia or in the presence of high glucose concentrations in vitro.

METHODS

Plasmids expressing loops 2-3 and loops 2-4 of sFlt-1 were packed in carboxymethylated dextran-coated nanoparticles and transferred into human umbilical vein endothelial cells (HUVECs), which were then cultured under hypoxia or in a high-glucose environment. The proliferation and migration of HUVECs were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and low-power microscopy, respectively. Western blot analyses were performed to detect p-ERK1/2 protein expression.

RESULTS

After transfection with the sFlt-1(2-3) or sFlt-1(2-4) gene fragment, the proliferation and migration of HUVECs were markedly reduced, and p-ERK1/2 protein expression was down-regulated under both hypoxic and high-glucose conditions. The impacts on the proliferation, migration of HUVECs, and on p-ERK1/2 protein expression did not differ significantly between the sFlt-1(2-3) and sFlt-1(2-4) gene fragments.

CONCLUSIONS

Both sFlt-1(2-3) and sFlt-1(2-4) gene fragments inhibited the proliferation and migration of HUVECs, as well as signal transduction in the ERK1/2 pathway of VEGF.

Polymorphisms of TGFB1 and VEGF genes and survival of patients with gastric cancer

Background

Some TGFB1 and VEGF polymorphisms are believed to be functional. Given that these genes are involved in tumor growth and progression including angiogenesis, dissemination, and invasiveness, we hypothesized that these polymorphisms would be associated with survival in patients with gastric cancer.

Methods

We genotyped TGFB1 -509 C>T, +1869 T>C, and +915 G>C and VEGF -1498T>C, -634G>C, and +936C>T in 167 patients with gastric cancer. Using the Kaplan and Meier method, log-rank tests, and Cox proportional hazard models, we evaluated associations among TGFB1 and VEGF variants with overall, 1-year, and 2-year survival rates.

Results

Although there were no significant differences in overall survival rates among all polymorphisms tested, patients with TGFB1+915CG and CC genotypes had a poorer 2-year survival (adjusted hazard ratio (HR), 3.06; 95% confidence interval (CI), 1.09–8.62; P = 0.034) than patients with the GG genotype had. In addition, patients heterozygous for VEGF -634CG also had a poorer 1-year survival (adjusted HR, 2.08; 95% CI, 1.03–4.22; P = 0.042) than patients with the -634GG genotype.

Conclusion

Our study suggested that TGFB1+915CG/CC and VEGF -634CG genotypes may be associated with short-term survival in gastric cancer patients. However, larger studies are needed to verify these findings.