Expression of vascular endothelial growth factor C (VEGF-C) and VEGF receptor-3 in human prostate cancer is associated with regional lymph node metastasis

Vascular endothelial growth factor-C and its receptor-3 signaling in tumorigenesis

The cancer-promoting ligand vascular endothelial growth factor-C (VEGF-C) activates VEGF receptor-3 (VEGFR-3). The VEGF-C/VEGFR-3 axis is expressed by a range of human tumor cells in addition to lymphatic endothelial cells. Activating the VEGF-C/VEGFR-3 signaling enhances metastasis by promoting lymphangiogenesis and angiogenesis inside and around tumors. Stimulation of VEGF-C/VEGFR-3 signaling promotes tumor metastasis in tumors, such as ovarian, renal, pancreatic, prostate, lung, skin, gastric, colorectal, cervical, leukemia, mesothelioma, Kaposi sarcoma, and endometrial carcinoma. We discuss and update the role of VEGF-C/VEGFR-3 signaling in tumor development and the research is still needed to completely comprehend this multifunctional receptor.

Vascular Endothelial Growth Factor Receptors [VEGFR] as Target in Breast Cancer Treatment: Current Status in Preclinical and Clinical Studies and Future Directions

Breast cancer [BC] is one of the most common cancers among women, one of the leading causes of a considerable number of cancer-related death globally. Among all procedures leading to the formation of breast tumors, angiogenesis has an important role in cancer progression and outcomes. Therefore, various anti-angiogenic strategies have developed so far to enhance treatment's efficacy in different types of BC. Vascular endothelial growth factors [VEGFs] and their receptors are regarded as the most well-known regulators of neovascularization. VEGF binding to vascular endothelial growth factor receptors [VEGFRs] provides cell proliferation and vascular tissue formation by the subsequent tyrosine kinase pathway. VEGF/VEGFR axis displays an attractive target for anti-angiogenesis and anti-cancer drug design. This review aims to describe the existing literature regarding VEGFR inhibitors, focusing on BC treatment reported in the last two decades.

KLK3 in the Regulation of Angiogenesis-Tumorigenic or Not?

In this focused review, we address the role of the kallikrein-related peptidase 3 (KLK3), also known as prostate-specific antigen (PSA), in the regulation of angiogenesis. Early studies suggest that KLK3 is able to inhibit angiogenic processes, which is most likely dependent on its proteolytic activity. However, more recent evidence suggests that KLK3 may also have an opposite role, mediated by the ability of KLK3 to activate the (lymph)angiogenic vascular endothelial growth factors VEGF-C and VEGF-D, further discussed in the review.

Angiogenesis and Anti-Angiogenic Treatment in Prostate Cancer: Mechanisms of Action and Molecular Targets

Prostate cancer (PC) is the most common cancer in men and the second leading cause of cancer-related death worldwide. Many therapeutic advances over the last two decades have led to an improvement in the survival of patients with metastatic PC, yet the majority of these patients still succumb to their disease. Antiagiogenic therapies have shown substantial benefits for many types of cancer but only a marginal benefit for PC. Ongoing clinical trials investigate antiangiogenic monotherapies or combination therapies. Despite the important role of angiogenesis in PC, clinical trials in refractory castration-resistant PC (CRPC) have demonstrated increased toxicity with no clinical benefit. A better understanding of the mechanism of angiogenesis may help to understand the failure of trials, possibly leading to the development of new targeted anti-angiogenic therapies in PC. These could include the identification of specific subsets of patients who might benefit from these therapeutic strategies. This paper provides a comprehensive review of the pathways involved in the angiogenesis, the chemotherapeutic agents with antiangiogenic activity, the available studies on anti-angiogenic agents and the potential mechanisms of resistance.

MAZ51 Blocks the Tumor Growth of Prostate Cancer by Inhibiting Vascular Endothelial Growth Factor Receptor 3

Vascular endothelial growth factor (VEGF) signaling plays a critical role in the carcinogenesis and tumor development of several cancer types. However, its pathological significance in prostate cancer, one of the most frequent and lethal malignancies in men, remains unclear. In the present study, we focused on a pathological role of the VEGF receptors (VEGFRs), and examined their expression and effects of MAZ51 (an inhibitor of the tyrosine kinase of VEGFR-3) on cell proliferation, migration, and tumor growth in human prostate cancer cells. The expression level of VEGFR-3 was higher in androgen-independent and highly metastatic prostate cancer PC-3 cells than in other prostate PrEC, LNCaP, and DU145 cells. In PC-3 cells, VEGFR-3 and Akt were phosphorylated following a stimulation with 50 ng/ml VEGF-C, and these phosphorylations were blocked by 3 μM MAZ51. Interestingly, PC-3 cells themselves secreted VEGF-C, which was markedly larger amount compared with PrEC, LNCaP, and DU145 cells. MAZ51 reduced the expression of VEGFR-3 but not VEGFR-1 and VEGFR-2. The proliferation of PC-3 cells was inhibited by MAZ51 (IC₅₀ = 2.7 μM) and VEGFR-3 siRNA, and partly decreased by 100 nM GSK690693 (an Akt inhibitor) and 300 nM VEGFR2 Kinase Inhibitor I. MAZ51 and VEGFR-3 siRNA also attenuated the VEGF-C-induced migration of PC-3 cells. Moreover, MAZ51 blocked the tumor growth of PC-3 cells in a xenograft mouse model. These results suggest that VEGFR-3 signaling contributes to the cell proliferation, migration, and tumor growth of androgen-independent/highly metastatic prostate cancer. Therefore, the inhibition of VEGFR-3 has potential as a novel therapeutic target for the treatment for prostate cancer.

Metastatic Spread in Prostate Cancer Patients Influencing Radiotherapy Response

Radiotherapy and surgery are curative treatment options for localized prostate cancer (PCa) with a 5-year survival rate of nearly 100%. Once PCa cells spread into distant organs, such as bone, the overall survival rate of patients drops dramatically. The metastatic cascade and organotropism of PCa cells are regulated by different cellular subtypes, organ microenvironment, and their interactions. This cross-talk leads to pre-metastatic niche formation that releases chemo-attractive factors enforcing the formation of distant metastasis. Biological characteristics of PCa metastasis impacting on metastatic sites, burden, and latency is of clinical relevance. Therefore, the implementation of modern hybrid imaging technologies into clinical routine increased the sensitivity to detect metastases at earlier stages. This enlarged the number of PCa patients diagnosed with a limited number of metastases, summarized as oligometastatic disease. These patients can be treated with androgen deprivation in combination with local-ablative radiotherapy or radiopharmaceuticals directed to metastatic sites. Unfortunately, the number of patients with disease recurrence is high due to the enormous heterogeneity within the oligometastatic patient population and the lack of available biomarkers with predictive potential for metastasis-directed radiotherapy. Another, so far unmet clinical need is the diagnosis of minimal residual disease before onset of clinical manifestation and/or early relapse after initial therapy. Here, monitoring of circulating and disseminating tumor cells in PCa patients during the course of radiotherapy may give us novel insight into how metastatic spread is influenced by radiotherapy and vice versa. In summary, this review critically compares current clinical concepts for metastatic PCa patients and discuss the implementation of recent preclinical findings improving our understanding of metastatic dissemination and radiotherapy resistance into standard of care.

Chromatin conformation changes in peripheral blood can detect prostate cancer and stratify disease risk groups

BACKGROUND

Current diagnostic blood tests for prostate cancer (PCa) are unreliable for the early stage disease, resulting in numerous unnecessary prostate biopsies in men with benign disease and false reassurance of negative biopsies in men with PCa. Predicting the risk of PCa is pivotal for making an informed decision on treatment options as the 5-year survival rate in the low-risk group is more than 95% and most men would benefit from surveillance rather than active treatment. Three-dimensional genome architecture and chromosome structures undergo early changes during tumourigenesis both in tumour and in circulating cells and can serve as a disease biomarker.

METHODS

In this prospective study we screened whole blood of newly diagnosed, treatment naïve PCa patients (n = 140) and cancer-free controls (n = 96) for the presence of 14,241 chromosomal loops in the loci of 425 genes.

RESULTS

We have detected specific chromosome conformation changes in the loci of ETS1, MAP3K14, SLC22A3 and CASP2 genes in peripheral blood from PCa patients yielding PCa detection with 80% sensitivity and 80% specificity. Further analysis between PCa risk groups yielded prognostic validation sets consisting of HSD3B2, VEGFC, APAF1, BMP6, ERG, MSR1, MUC1, ACAT1 and DAPK1 genes that achieved 80% sensitivity and 93% specificity stratifying high-risk category 3 vs low risk category 1 and 84% sensitivity and 89% specificity stratifying high risk category 3 vs intermediate risk category 2 disease.

CONCLUSIONS

Our results demonstrate specific chromosome conformations in the blood of PCa patients that allow PCa diagnosis and risk stratification with high sensitivity and specificity.

Cytokines and Chemokines as Mediators of Prostate Cancer Metastasis

The consequences of prostate cancer metastasis remain severe, with huge impact on the mortality and overall quality of life of affected patients. Despite the convoluted interplay and cross talk between various cell types and secreted factors in the metastatic process, cytokine and chemokines, along with their receptors and signaling axis, constitute important factors that help drive the sequence of events that lead to metastasis of prostate cancer. These proteins are involved in extracellular matrix remodeling, epithelial-mesenchymal-transition, angiogenesis, tumor invasion, premetastatic niche creation, extravasation, re-establishment of tumor cells in secondary organs as well as the remodeling of the metastatic tumor microenvironment. This review presents an overview of the main cytokines/chemokines, including IL-6, CXCL12, TGFβ, CXCL8, VEGF, RANKL, CCL2, CX3CL1, IL-1, IL-7, CXCL1, and CXCL16, that exert modulatory roles in prostate cancer metastasis. We also provide extensive description of their aberrant expression patterns in both advanced disease states and metastatic sites, as well as their functional involvement in the various stages of the prostate cancer metastatic process.

KLK3/PSA and cathepsin D activate VEGF-C and VEGF-D

Vascular endothelial growth factor-C (VEGF-C) acts primarily on endothelial cells, but also on non-vascular targets, for example in the CNS and immune system. Here we describe a novel, unique VEGF-C form in the human reproductive system produced via cleavage by kallikrein-related peptidase 3 (KLK3), aka prostate-specific antigen (PSA). KLK3 activated VEGF-C specifically and efficiently through cleavage at a novel N-terminal site. We detected VEGF-C in seminal plasma, and sperm liquefaction occurred concurrently with VEGF-C activation, which was enhanced by collagen and calcium binding EGF domains 1 (CCBE1). After plasmin and ADAMTS3, KLK3 is the third protease shown to activate VEGF-C. Since differently activated VEGF-Cs are characterized by successively shorter N-terminal helices, we created an even shorter hypothetical form, which showed preferential binding to VEGFR-3. Using mass spectrometric analysis of the isolated VEGF-C-cleaving activity from human saliva, we identified cathepsin D as a protease that can activate VEGF-C as well as VEGF-D.

The lymphatic system is composed of networks of vessels that drain fluids from the body’s tissues and filter it back into the blood. Growing these vessels depends on a factor known as VEGF-C, which is released in an inactive form and must be cut by enzymes before it can work. One enzyme that is known to activate the VEGF-C signal when the early embryo is developing is ADAMTS3. If this signal fails to switch on this can result in a condition known as lymphedema – whereby problems in the lymphatic system cause tissues to swell due to insufficient drainage. However, it is unknown whether the VEGF-C signal can be activated by enzymes other than ADAMTS3.

To investigate this Jha, Rauniyar et al. tested a specific family of proteins commonly found in the human prostate, which have previously been predicted to act on VEGF-C. This revealed that the lymphatic vessel growth factor can also be activated by an enzyme found in seminal fluid called prostate specific antigen, or PSA for short. To see if enzymes in other bodily fluids could switch on VEGF-C, different components of human saliva were separated and tested to see which could cut inactive VEGF-C. This showed that VEGF-C could be converted to an active form by another enzyme called cathepsin D.

Unexpectedly, Jha, Rauniyar et al. found that VEGF-C was also present in semen. For conception to occur PSA must liquify the semen following ejaculation. It was discovered that PSA activates VEGF-C just as the semen starts to liquify, suggesting that the lymphatic vessel growth factor might also play an important role in reproduction. In addition to VEGF-C, both PSA and cathepsin D were found to activate another growth factor called VEGF-D, which has an unknown role in the human body.

VEGF-C helps the spread of tumors, and blocking the two enzymes that activate this growth factor may be a new therapeutic approach for cancer. However, more work is needed to validate which types of tumor, if any, use these enzymes to activate VEGF-C. In addition, understanding the relationship between PSA and VEGF-C could help improve our knowledge of human reproduction.

Ginsenoside Rg3 Inhibition of Thyroid Cancer Metastasis Is Associated with Alternation of Actin Skeleton

Ginsenoside Rg3, a bioactive constituent from Panax ginseng, is a worldwide well-known traditional Chinese medicine used as a tonic. It also has good antitumor activity by inhibiting tumors metastasis. Tumor metastasis is a high risk in thyroid cancer. However, the effect and molecular mechanism underlying the antimetastatic activity of Rg3 in thyroid cancer have not been reported. In our study, we found that Rg3 inhibited the growth of thyroid cancer in vitro and in vivo and significantly inhibited metastasis of thyroid cancer. Rg3 apparently inhibited the migration and invasion in four papillary thyroid cancer (PTC) cells (TPC-1, BCPAP, C643, and Ocut-2c cells) and pulmonary metastasis in lung metastasis model of C643 cells in nude mice. We further found that a possible mechanism of Rg3 inhibiting thyroid cancer cells metastasis was associated with inhibiting cells actin skeleton function. Rg3 inhibited lamellipodia formation and induced microspike formation by inhibiting Rho GTPase in thyroid cancer cells. Rg3 decreased the levels of Rac-1 and Cdc42 proteins. In addition, Rg3 decreased the expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins in four thyroid cancer cells. The results that Rg3 remarkably inhibited the expression of vascular endothelial growth factor-C (VEGF-C) protein in PTC cells and VEGF-A protein in anaplastic thyroid cancer (ATC) cells and decreased the staining of CD31 in PTC and ATC tumors hinted that Rg3 might inhibit the lymph node metastasis in PTC and angiogenesis in ATC. These studies suggested that Rg3 might be a useful agent for the treatment of metastatic thyroid cancers.

Expression of VEGFR-3 in intrahepatic cholangiocarcinoma correlates with unfavorable prognosis through lymphangiogenesis

Background & aims: VEGFR-3 has been shown of great significance in lymph node metastasis and some malignancies, however, its expression in tumors and impact on outcome of intrahepatic cholangiocarcinoma (iCCA) remains unknown. The aim of this study was to assess the role of VEGFR-3 positive tumors for prognosis of iCCA and tumor-associated lymphangiogenesis.

Methods: Clinicopathological features, prognostic factors and survival rate were analyzed to evaluate the influence of VEGFR-3 positive expression on prognosis of iCCA. In addition, tumor-associated lymphangiogenesis quantified as micro-lymphatic vessel density (MLVD) was assessed to explore the correlation between VEGFR-3 expression and lymph node metastasis for iCCA.

Results: Patients with VEGFR-3 positive tumors had increased lymph node metastasis (p=0.025) and were more likely to suffer from tumor recurrence compared with VEGFR-3 negative tumors (p<0.001). VEGFR-3 expression in tumors was identified as an independent prognostic factor for both overall and recurrence-free survival in surgical resected patients with iCCA. In addition, higher MLVD was significantly associated with VEGFR-3 positive expression in tumors (p<0.001), which facilitate lymph node metastasis and significantly worse survival rates.

Conclusions: Our study reveals that VEGFR-3 positive expression in tumors represents an independent prognostic factor for both overall and recurrence-free survival in hepatic resected patients with iCCA. VEGFR-3 positive tumors favor lymph node metastasis, tumor recurrence and worse outcomes through tumor-associated lymphangiogenesis.

LPA1/3 signaling mediates tumor lymphangiogenesis through promoting CRT expression in prostate cancer

Lysophosphatidic acid (LPA) is a bioactive lipid growth factor which is present in high levels in serum and platelets. LPA binds to its specific G-protein-coupled receptors, including LPA₁ to LPA₆, thereby regulating various physiological functions, including cancer growth, angiogenesis, and lymphangiogenesis. Our previous study showed that LPA promotes the expression of the lymphangiogenic factor vascular endothelial growth factor (VEGF)-C in prostate cancer (PCa) cells. Interestingly, LPA has been shown to regulate the expression of calreticulin (CRT), a multifunctional chaperone protein, but the roles of CRT in PCa progression remain unclear. Here we investigated the involvement of CRT in LPA-mediated VEGF-C expression and lymphangiogenesis in PCa. Knockdown of CRT significantly reduced LPA-induced VEGF-C expression in PC-3 cells. Moreover, LPA promoted CRT expression through LPA receptors LPA₁ and LPA₃, reactive oxygen species (ROS) production, and phosphorylation of eukaryotic translation initiation factor 2α (eIF2α). Tumor-xenografted mouse experiments further showed that CRT knockdown suppressed tumor growth and lymphangiogenesis. Notably, clinical evidence indicated that the LPA-producing enzyme autotaxin (ATX) is related to CRT and that CRT level is highly associated with lymphatic vessel density and VEGF-C expression. Interestingly, the pharmacological antagonist of LPA receptors significantly reduced the lymphatic vessel density in tumor and lymph node metastasis in tumor-bearing nude mice. Together, our results demonstrated that CRT is critical in PCa progression through the mediation of LPA-induced VEGF-C expression, implying that targeting the LPA signaling axis is a potential therapeutic strategy for PCa.

Therapeutic Potency of Nanoformulations of siRNAs and shRNAs in Animal Models of Cancers

RNA Interference (RNAi) has brought revolutionary transformations in cancer management in the past two decades. RNAi-based therapeutics including siRNA and shRNA have immense scope to silence the expression of mutant cancer genes specifically in a therapeutic context. Although tremendous progress has been made to establish catalytic RNA as a new class of biologics for cancer management, a lot of extracellular and intracellular barriers still pose a long-lasting challenge on the way to clinical approval. A series of chemically suitable, safe and effective viral and non-viral carriers have emerged to overcome physiological barriers and ensure targeted delivery of RNAi. The newly invented carriers, delivery techniques and gene editing technology made current treatment protocols stronger to fight cancer. This review has provided a platform about the chronicle of siRNA development and challenges of RNAi therapeutics for laboratory to bedside translation focusing on recent advancement in siRNA delivery vehicles with their limitations. Furthermore, an overview of several animal model studies of siRNA- or shRNA-based cancer gene therapy over the past 15 years has been presented, highlighting the roles of genes in multiple cancers, pharmacokinetic parameters and critical evaluation. The review concludes with a future direction for the development of catalytic RNA vehicles and design strategies to make RNAi-based cancer gene therapy more promising to surmount cancer gene delivery challenges.

Utilizing Zebrafish to Identify Anti-(Lymph)Angiogenic Compounds for Cancer Treatment: Promise and Future Challenges

Cancer metastasis which predominantly occurs through blood and lymphatic vessels, is the leading cause of death in cancer patients. Consequently, several anti-angiogenic agents have been approved as therapeutic agents for human cancers such as metastatic renal cell carcinoma. Also, anti-lymphangiogenic drugs such as monoclonal antibodies VGX-100 and IMC-3C5 have undergone phase I clinical trials for advanced and metastatic solid tumors. Although anti-tumor-associated angiogenesis has proven to be a promising therapeutic strategy for human cancers, this approach is fraught with toxicities and development of drug resistance. This emphasizes the need for alternative anti-(lymph)angiogenic drugs. The use of zebrafish has become accepted as an established model for high-throughput screening, vascular biology, and cancer research. Importantly, various zebrafish transgenic lines have now been generated that can readily discriminate different vascular compartments. This now enables detailed in vivo studies that are relevant to both human physiological and tumor (lymph)angiogenesis to be conducted in zebrafish. This review highlights recent advancements in the zebrafish anti-vascular screening platform and showcases promising new anti-(lymph)angiogenic compounds that have been derived from this model. In addition, this review discusses the promises and challenges of the zebrafish model in the context of anti-(lymph)angiogenic compound discovery for cancer treatment.

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.

Association between protocadherin 8 promoter hypermethylation and the pathological status of prostate cancer

Promoter hypermethylation of tumor suppressor genes has been confirmed to serve a pivotal role in tumorigenesis. Protocadherin 8 (PCDH8), a novel tumor suppressor gene, has been reported to be inactivated by promoter hypermethylation a number of cancer types, including bladder cancer and renal cell carcinoma. The aim of the present study was to investigate the occurrence of PCDH8 hypermethylation in prostate cancer and its potential as a novel biomarker of prostate cancer. The transcriptional levels of PCDH8 were examined by quantitative polymerase chain reaction (PCR) in 82 prostate cancer tissues as well as 30 prostate hyperplasia tissues, and verified the protein level by western blot analysis of representative samples. PCDH8 expression levels were found to be reduced to 0.30±0.10 in 70.7% (58/82) of prostate cancer tissues. To identify the possible reason for mRNA downregulation, the methylation status of the PCDH8 promoter was assessed in prostate cancer tissues and prostate hyperplasia tissues by methylation-specific PCR (MSP). A total of 47 prostate cancer patients who exhibited reduced PCDH8 expression (57.3%; 47/82) also showed promoter hypermethylation (47/58). None of the samples (0/30) in the benign prostate hyperplasia group were positive on MSP. Furthermore, the associations between the methylation status of the PCDH8 promoter and various clinicopathological features of prostate cancer were analyzed, revealing that the methylation status of PCDH8 was closely associated with tumor size, tumor shape (papillary/non-papillary), tumor stage and tumor grade (all P<0.05), while there were no correlations with the age of the patients or the number of tumors (P>0.05). Additionally, patients with hypermethylation of the PCDH8 gene promoter had a relapse rate of 36.17% and a mortality rate of 29.79%, which were significantly higher than the hypermethylation-negative patients (P<0.05), indicating a poorer prognosis. Therefore, the methylation status of the PCDH8 gene in prostate cancer may be an important marker for use in the early diagnosis and prediction of prognosis in prostate cancer.

Effect of VEGF-C siRNA and endostatin on ring formation and proliferation of esophageal squamous cell carcinoma lymphatic endothelial cells

Objective

To study the effects of vascular endothelial growth factor C small interfering RNA and endostatin on esophageal squamous cell carcinoma-related ring formation in vitro and proliferation of lymphatic endothelial cells.

Materials and methods

KYSE150 cells were subjected to analysis of cell transfection and endostatin operation. The groups were as follows: negative group, blank group, negative plus endostatin group, endostatin group, SG1 group, SG2 group, SG1 plus endostatin group, and SG2 plus endostatin group. The esophageal cancer-related microlymphatic endothelial cells were three-dimensionally cultured. Cell Counting Kit-8 (CCK-8) assay was employed to detect cell proliferation.

Results

The negative group’s three-dimensional culture result was the highest, followed by the blank group, negative plus endostatin group, endostatin group, SG2 group, SG1 group, SG1 plus endostatin group, and SG2 plus endostatin group. The quantity of living cells in the blank group was the highest, followed by the negative control, endostatin, SG2, SG1, negative plus endostatin, SG1 plus endostatin, and SG2 plus endostatin groups.

Conclusion

Both vascular endothelial growth factor C small interfering RNA and endostatin could inhibit ring formation in esophageal squamous cell carcinoma and proliferation of lymphatic endothelial cells.

Activity of Artemisia annua and artemisinin derivatives, in prostate carcinoma

BACKGROUND

Artemisia annua L, artemisinin and artesunate reveal profound activity not only against malaria, but also against cancer in vivo and clinical trials. Longitudinal observations on the efficacy of A. annua in patients are, however missing as of yet.

METHODS

Clinical diagnosis was performed by imaging techniques (MRT, scintigraphy, SPECT/CT) and blood examinations of standard parameters from clinical chemistry. Immunohistochemistry of formalin-fixed, paraffin-embedded tumor material was performed to determine the expression of several biomarkers (cycloxygenase-2 (COX2), epidermal growth factor receptor (EGFR), glutathione S-transferase P1 (GSTP1), Ki-67, MYC, oxidized low density lipoprotein (lectin-like) receptor 1 (LOX1), p53, P-glycoprotein, transferrin receptor (TFR, CD71), vascular endothelial growth factor (VEGF), von Willebrand factor (CD31)). The immunohistochemical expression has been compared with the microarray-based mRNA expression of these markers in two prostate carcinoma cell lines (PC-3, DU-145).

RESULTS

A patient with prostate carcinoma (pT3bN1M1, Gleason score 8 (4+4)) presented with a prostate specific antigen (PSA) level >800 µg/l. After short-term treatment with bacalitumide (50 mg/d for 14 days) and long-term oral treatment with A. annua capsules (continuously 5 × 50 mg/d), the PSA level dropped down to 0.98 µg/l. MRT, scintigraphy and SPECT/CT verified tumor remission. Seven months later, PSA and ostase levels increased, indicating tumor recurrence and skeletal metastases. Substituting A. annua capsules by artesunate injections (2 × 150 mg twice weekly i.v.) did not prohibit tumor recurrence. PSA and ostase levels rose to 1245 µg/l and 434 U/l, respectively, and MRT revealed progressive skeletal metastases, indicating that the tumor acquired resistance. The high expression of MYC, TFR, and VEGFC in the patient biopsy corresponded with high expression of these markers in the artemisinin-sensitive PC-3 cells compared to artemisinin-resistant DU-145 cells.

CONCLUSION

Long-term treatment with A. annua capsules combined with short-term bicalitumide treatment resulted in considerable regression of advanced metastasized prostate carcinoma. Controlled clinical trials are required to evaluate the clinical benefit of A. annua in prostate cancer.

Prolactin- and testosterone-induced carboxypeptidase-D correlates with increased nitrotyrosines and Ki67 in prostate cancer

BACKGROUND

Carboxypeptidase-D (CPD) cleaves C-terminal arginine for conversion to nitric oxide (NO) by nitric oxide synthase (NOS). Prolactin (PRL) and androgens stimulate CPD gene transcription and expression, which increases intracellular production of NO to promote viability of prostate cancer (PCa) cells in vitro. The current study evaluated whether hormonal upregulation of CPD and NO promote PCa cell viabilty in vivo, by correlating changes in expression of CPD and nitrotyrosine residues (products of NO action) with proliferation marker Ki67 and associated proteins during PCa development and progression.

METHODS

Fresh prostate tissues, obtained from 40 men with benign prostatic hyperplasia (BPH) or PCa, were flash-frozen at the time of surgery and used for RT-qPCR analysis of CPD, androgen receptor (AR), PRL receptor (PRLR), eNOS, and Ki67 levels. Archival paraffin-embedded tissues from 113 men with BPH or PCa were used for immunohistochemical (IHC) analysis of CPD, nitrotyrosines, phospho-Stat5 (for activated PRLR), AR, eNOS/iNOS, and Ki67.

RESULTS

RT-qPCR and IHC analyses showed strong AR and PRLR expression in benign and malignant prostates. CPD mRNA levels increased ∼threefold in PCa compared to BPH, which corresponded to a twofold increase in Ki67 mRNA levels. IHC analysis showed a progressive increase in CPD from 11.4 ± 2.1% in benign to 21.8 ± 3.2% in low-grade (P = 0.007), 40.7 ± 4.0% in high-grade (P < 0.0001) and 50.0 ± 9.5% in castration-recurrent PCa (P < 0.0001). Immunostaining for nitrotyrosines and Ki67 mirrored these increases during PCa progression. CPD, nitrotyrosines, and Ki67 tended to co-localize, as did phospho-Stat5.

CONCLUSIONS

CPD, nitrotyrosine, and Ki67 levels were higher in PCa than in benign and tended to co-localize, along with phospho-Stat5. The strong correlation in expression of these proteins in benign and malignant prostate tissues, combined with abundant AR and PRLR, supports in vitro evidence that the CPD-Arg-NO pathway is involved in the regulation of PCa cell proliferation. It further highlights a role for PRL in the development and progression of PCa.

Dysregulation of the vascular endothelial growth factor and semaphorin ligand-receptor families in prostate cancer metastasis

Background

The vascular endothelial growth factor (VEGF) family is central to cancer angiogenesis. However, targeting VEGF as an anti-cancer therapeutic approach has shown success for some tumor types but not others. Here we examine the expression of the expanded VEGF family in prostate cancer, including the Semaphorin (Sema) family members that compete with VEGFs for Neuropilin binding and can themselves have pro- or anti-angiogenic activity.

Results

First, we used multivariate statistical methods, including partial least squares and clustering, to examine VEGF/Sema gene expression variability in previously published prostate cancer microarray datasets. We show that unlike some cancers, such as kidney cancer, primary prostate cancer is characterized by both a down-regulation of the pro-angiogenic members of the VEGF family and a down-regulation of anti-angiogenic members of the Sema family. We found pro-lymphangiogenic signatures, including the genes encoding VEGFC and VEGFD, associated with primary tumors that ultimately became aggressive. In contrast to primary prostate tumors, prostate cancer metastases showed increased expression of key pro-angiogenic VEGF family members and further repression of anti-angiogenic class III Sema family members. Given the lack of success of VEGF-targeting molecules so far in prostate cancer, this suggests that the reduction in anti-angiogenic Sema signaling may potentiate VEGF signaling and even promote resistance to VEGF-targeting therapies. Inhibition of the VEGF ‘accelerator’ may need to be accompanied by promotion of the Sema ‘brake’ to block cancer angiogenesis. To leverage our mechanistic understanding, and to link multigene expression changes to outcomes, we performed individualized computational simulations of competitive VEGF and Sema receptor binding across many tumor samples. The simulations suggest that loss of Sema expression promotes angiogenesis by lowering plexin signaling, not by potentiating VEGF signaling via relaxation of competition.

Conclusions

The combined analysis of bioinformatic data with computational modeling of ligand-receptor interactions demonstrated that enhancement of angiogenesis in prostate cancer metastases may occur through two different routes: elevation of VEGFA and reduction of class 3 Semaphorins. Therapeutic inhibition of angiogenesis in metastatic prostate cancer should account for both of these routes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12918-015-0201-z) contains supplementary material, which is available to authorized users.

Immunohistochemical study of vascular endothelial growth factor-C/vascular endothelial growth factor receptor-3 expression in oral tongue squamous cell carcinoma: Correlation with the induction of lymphangiogenesis

The aim of the present study was to elucidate the associations between the expression of the vascular endothelial growth factor-C (VEGF-C)/VEGF receptor-3 (VEGFR-3) axis and lymphangiogenesis, regional lymph node metastasis and clinicopathological factors in oral tongue squamous cell carcinoma (OTSCC) using immunohistochemistry. The expression of VEGF-C, VEGFR-3 and podoplanin was immunohistochemically evaluated in specimens obtained from 65 patients with OTSCC (T1-2, N0) who had undergone radical surgery alone. The associations between the expression of VEGF-C, VEGFR-3 and podoplanin, and lymphangiogenesis, regional lymph node metastasis and clinocopathological factors were determined by immunohistochemical analysis. VEGF-C, VEGFR-3 and combined VEGF-C/VEGFR-3 expression was significantly higher in cases with regional recurrence compared with those without lymph node involvement (P<0.001). As regards lymphangiogenesis, a significant correlation was observed between podoplanin expression and VEGF-C, VEGFR-3 and combined VEGF-C/VEGFR-3 expression (P<0.001). Therefore, lymphangiogenesis in the peritumoral stroma was associated with lymph node metastasis. However, podoplanin expression did not exhibit a significant correlation with the progression of lymph node metastasis. The results of the present study suggest that the VEGF-C/VEGFR-3 axis may be associated with lymph node metastasis through lymphangiogenesis. Determining the VEGF-C/VEGFR-3 expression status may help predict which patients will develop regional recurrence and provide novel targets for therapies to suppress lymph node metastasis in the treatment of OTSCC.

Non-caveolar caveolin-1 expression in prostate cancer cells promotes lymphangiogenesis

Lymphangiogenesis allows prostate cancer (PCa) lymphatic metastasis, which is associated with poor prognosis and short survival rates. Caveolin-1 (Cav-1) is a membrane protein localized in caveolae, but also exists in non-caveolar, cellular or extracellular forms. Cav-1 is overexpressed in PCa, promotes prostate tumour progression and metastasis. We investigated the effect of caveolar and non-caveolar Cav-1 on PCa lymphangiogenic potential. Cav-1 was down-regulated in PC3 and DU145, and ectopically expressed in LNCaP cells. The effect of PCa cell conditioned media on lymphatic endothelial cell (LEC) viability, chemotaxis, chemokinesis and differentiation was assessed. The effect of Cav-1 on PCa cell expression of lymphangiogenesis-modulators VEGF-A and VEGF-C was assessed using qPCR and ELISA of the conditioned medium. Non-caveolar Cav-1, whether exogenous or endogenous (in LNCaP and PC3 cells, respectively) enhanced LEC proliferation, migration and differentiation. In contrast, caveolar Cav-1 (in DU145 cells) did not significantly affect PCa cell lymphangiogenic potential. The effect of non-caveolar Cav-1 on LECs was mediated by increased expression of VEGF-A as demonstrated by neutralization by anti-VEGF-A antibody. This study unveils for the first time a crucial role for non-caveolar Cav-1 in modulating PCa cell expression of VEGF-A and subsequent LEC proliferation, migration and tube formation.

Pivotal role of vascular endothelial growth factor pathway in tumor angiogenesis

The shaping of new blood vessels is a significant event in cancer growth and metastasis. Therefore, the molecular system of cancer angiogenesis has garnered considerable interest in cancer research. The vascular endothelial growth factor (VEGF) and VEGF receptor pathway are recognized as the key regulators of the angiogenic process. Activation of the VEGF/VEGF-receptor pathway initiates signaling cascades that promote endothelial cell growth, migration, and differentiation. Recently, VEGF was shown to play a role in the recruitment of bone marrow-derived endothelial progenitor cells to neovascularization sites. The role of VEGF in promoting tumor angiogenesis and the occurrence of human cancers has led to the rational design and development of agents that selectively target this pathway. Moreover, these anti-VEGF/VEGF receptor agents show therapeutic potential by inhibition of angiogenesis and tumor growth in preclinical models. In this review, we summarize the role of the VEGF pathway during tumor angiogenesis.

The non-canonical role of vascular endothelial growth factor-C axis in cancer progression

It has been shown in many clinical studies that the level of vascular endothelial growth factor-C (VEGF-C) positively correlates with lymph node metastasis. Nevertheless, beyond the canonical role of VEGF-C in stimulating lymphangiogenesis and thus promoting lymph node/distant metastasis, emerging evidence indicates that expression of VEGF-C contributes to various aspects of carcinogenicity via autocrine regulation. The newly identified functions of VEGF-C include but are not limited to proliferation, migration, invasion, and chemo-resistance. Besides tumor cell autocrine regulation, VEGF-C can also modulate the immune system such that tumor cells more easily escape immune surveillance. Therefore, understanding the functional roles and regulatory mechanisms related to the VEGF-C axis may lead to alternative strategies for cancer treatment. This mini-review will focus on summarizing recent discoveries regarding the unconventional functions of VEGF-C in cancer progression.

Comprehensive analysis of vascular endothelial growth factor-C related factors in stomach cancer

BACKGROUND

Vascular endothelial growth factor-C (VEGF-C), which contributes to lymphatic metastasis (LM) in malignant disease, is one of the most important factors involved in physical and pathological lymphangiogenesis. Some VEGF-C related factors such as sine oculis homeobox homolog (SIX) 1, contactin (CNTN) 1 and dual specificity phosphatase (DUSP) 6 have been extensively studied in malignancies, but their expression levels and associations have still to be elucidated in stomach cancer.

METHODS

We detected their expression levels in 30 paired stomach cancer tissues using quantitative real-time reverse transcription-PCR (qRT-PCR). The expression and clinical significance of each factor was analyzed using Wilcoxon signed rank sum test. The correlation among all the factors was performed by Spearman rank correlation analysis.

RESULTS

The results suggest that VEGF-C and CNTN1 are significantly correlated with tumor size, SIX1 with the age and CNTN1 also with the cTNM stage. There are significant correlations of expression levels among VEGF-C, SIX1, CNTN1 and DUSP6.

CONCLUSIONS

There exists an important regulatory crosstalk involving SIX1, VEGF-C, CNTN1 and DUSP6 in stomach cancer.

PTRF/Cavin-1 decreases prostate cancer angiogenesis and lymphangiogenesis

Caveolae are specialized plasma membrane subdomains implicated in cellular functions such as migration, signalling and trafficking. Caveolin-1 and polymerase I and transcript release factor (PTRF)/cavin-1 are essential for caveola formation. Caveolin-1 is overexpressed and secreted in prostate tumors and promotes aggressiveness and angiogenesis. In contrast, a lack of PTRF expression is reported in prostate cancer, and ectopic PTRF expression in prostate cancer cells inhibits tumor growth and metastasis. We experimentally manipulated PTRF expression in three prostate cancer cell lines, namely the caveolin-1 positive cells PC3 and DU145 and the caveolin-1-negative LNCaP cells, to evaluate angiogenesis- and lymphangiogenesis-regulating functions of PTRF. We show that the conditioned medium of PTRF-expressing prostate cancer cells decreases ECs proliferation, migration and differentiation in vitro and ex vivo. This can occur independently from caveolin-1 expression and secretion or caveola formation, since the anti-angiogenic effects of PTRF were detected in caveolin-1-negative LNCaP cells. Additionally, PTRF expression in PC3 cells significantly decreased blood and lymphatic vessel densities in orthotopic tumors in mice. Our results suggest that the absence of PTRF in prostate cancer cells contributes significantly to tumour progression and metastasis by promoting the angiogenesis and lymphangiogenesis potential of the cancer cells, and this could be exploited for therapy.

[How do metastases of urological tumors develop?]

This overview mainly focuses on the topic of epithelial tumors (carcinomas) because urological tumors are generally of this type. The importance of the topic is reflected by the fact that patients rarely die of the primary tumor, but the majority die of metastases that cause life-threatening situations. More recent findings show that treatment decisions should be based on the metastasis site and less on the tumor's tissue of origin. Given the progression of clinical oncology toward individualized medicine, a better understanding of the biology of metastases is therefore acute and includes some important challenges.

Semaphorin 4D expression is associated with a poor clinical outcome in cervical cancer patients

Lymphangiogenesis is thought to be essential for cancer progression, making it an important target in cancer therapy. Lymphangiogenic factors (VEGF-C and VEGF-D) are upregulated in various tumors/cancers, and play an important role in lymphangiogenesis and lymph node metastasis. Similarly, semaphorin 4D (Sema4D) is a potent inducer of angiogenesis, and its overexpression is associated with tumor progression and poor prognosis in a variety of malignancies. However, little is known regarding the functional relationship between Sema4D and VEGF-C/VEGF-D and in the mediation of lymphangiogenesis and lymph node metastasis and clinical outcome. The current study aimed to evaluate the effect of Sema4D expression on outcome in patients with cervical cancer, and to explore the molecular mechanism of Sema4D in tumor progression. We evaluated Sema4D expression, density of lymphatic vessels, and invasion of lymphatic vessels with immunohistochemical methods in 232 human cervical cancers with long-term follow-up. Sema4D expression was correlated with patho-clinical parameters and patients' outcome. A cervical cancer cell line was used to investigate the contribution of sema4D to tumor progression by studying the role of Sema4D in VEGF-C/-D and cell migration using reverse transcription-polymerase chain reaction and Western blotting. We observed that Sema4D expression was higher in metastatic cervical cancer than in nonmetastatic cervical cancer (P<0.001). CD34-positive or D2-40-positive lymphatic vessel density was significantly increased in cases with lymph node metastasis compared with those without lymph node metastasis. The increased Sema4D expression was associated with VEGF-C/-D, the presence of lymphatic invasion, the occurrence of lymph node metastasis, and FIGO stage. We also observed a novel association between Sema4D upregulation and poor prognosis in cervical cancer. In vitro, the Sema4D inhibitory antibody and Sema4D-shRNA suppressed VEGF-C and VEGF-D in the human cervical carcinoma cell lines HeLa, Siha, and Caski cells. Invasiveness assay demonstrated that Sema4D could augment the invasive potential of the tumor cells in the cervical cancer lines and induction of cellular invasiveness by Sema4D stimulation could be inhibited by knockdown of plexinB1 by siRNA. Further mechanistic investigations of tumor cell invasiveness showed that Sema4D could induce activation of GTPase Ras homolog gene family, member A (RhoA), MAPK and AKT. In addition, plexinB1 knockdown by siRNA could suppress the Sema4D signal transmitted to MAPK and Akt. Taken together, these results suggest that Sema4D autocrine within tumor cells contributes to enhanced invasion and tumor progression through increased motility of cervical cancer and VEGF-C/-D-mediated lymphangiogenesis. Sema4D might be useful as a molecular marker of poor prognosis in cervical 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.

Expression of vascular endothelial growth factor-C and vascular endothelial growth factor receptor-3 in esophageal squamous cell carcinoma

Lymph node metastasis is one of the most important prognostic factors in esophageal squamous cell carcinoma (ESCC). Vascular endothelial growth factor (VEGF)-C and its receptor, VEGF receptor-3 (VEGFR-3), are key in the process of lymphangiogenesis. The present study immunohistochemically examined the expression of VEGF-C, VEGFR-3 and D2-40 in 119 patients with ESCC, and microlymphatic vessel density (MLVD) was calculated based on D2-40 expression counts. Positive expression of VEGF-C was found to correlate significantly with depth of tumor invasion, lymphatic invasion and lymph node metastasis (P<0.001, P<0.0001 and P<0.0001, respectively). Patients with deeper tumor invasion showed higher positivity of VEGFR-3 expression (P<0.05), while patients with lymph node metastasis showed higher MLVD (P<0.05). When patients were divided into three groups according to the expression of VEGF-C and VEGFR-3, patients with coexpression of VEGF-C and VEGFR-3 exhibited poorer prognosis and higher MLVD. The VEGF-C/VEGFR-3 axis is important in tumor lymphangiogenesis.

Prostate cancer: the need for biomarkers and new therapeutic targets

Prostate cancer (PCa) incidence and mortality have decreased in recent years. Nonetheless, it remains one of the most prevalent cancers in men, being a disquieting cause of men's death worldwide. Changes in many cell signaling pathways have a predominant role in the onset, development, and progression of the disease. These include prominent pathways involved in the growth, apoptosis, and angiogenesis of the normal prostate gland, such as androgen and estrogen signaling, and other growth factor signaling pathways. Understanding the foundations of PCa is leading to the discovery of key molecules that could be used to improve patient management. The ideal scenario would be to have a panel of molecules, preferably detectable in body fluids, that are specific and sensitive biomarkers for PCa. In the early stages, androgen deprivation is the gold standard therapy. However, as the cancer progresses, it eventually becomes independent of androgens, and hormonal therapy fails. For this reason, androgen-independent PCa is still a major therapeutic challenge. By disrupting specific protein interactions or manipulating the expression of some key molecules, it might be possible to regulate tumor growth and metastasis formation, avoiding the systemic side effects of current therapies. Clinical trials are already underway to assess the efficacy of molecules specially designed to target key proteins or protein interactions. In this review, we address that recent progress made towards understanding PCa development and the molecular pathways underlying this pathology. We also discuss relevant molecular markers for the management of PCa and new therapeutic challenges.

Cyclooxygenase-2 expression is associated with vascular endothelial growth factor-c and lymph node metastasis in human oral tongue cancer

OBJECTIVE

This study aimed to determine the relationship of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-c (VEGF-C) expression with lymphangiogenesis, lymph node metastasis (LNM), and other clinicopathologic features in human oral tongue cancers.

STUDY DESIGN

Forty tongue cancer specimens were immunohistochemically examined for COX-2 and VEGF-C expression and for lymphatic vessel density (LVD). We analyzed the relationships between COX-2 and VEGF-C expression and the relationships of such expression with clinicopathologic findings and survival of patients.

RESULTS

Eighteen tumors out of 40 (45%) showed COX-2 expression, and 18 tumors (45%) expressed VEGF-C. Twelve tumors (30%) coexpressed COX-2/VEGF-C. A significant correlation was found between COX-2 and VEGF-C expression (P < .01). Of note, COX-2/VEGF-C coexpression significantly correlated with lymphangiogenesis, LNM, TNM stage (P < .01), and LVD (P < .05). In Cox regression for survival, COX-2/VEGF-C coexpression was identified as an independent prognostic factor (P < .05).

CONCLUSIONS

Our results suggest that examination of immunohistochemical expression of COX-2 and VEGF-C predicts LNM and survival in human oral tongue cancers.

Immunohistochemical expression of PDGFR, VEGF-C, and proteins of the mToR pathway before and after androgen deprivation therapy in prostate carcinoma: significant decrease after treatment

Targeted therapy in hormone refractory prostate cancer (HRPC) is currently under evaluation in many trials. The effect of androgen deprivation therapy (ADT) on many targets in prostate cancer is incompletely known. For the first time, immunohistochemical expression of the platelet-derived growth factor receptor (PDGFR), epidermal growth factor receptor (EGFR), vascular endothelial growth factor C (VEGF-C), mammalian target of rapamycin (mToR), p70 ribosomal protein S6 kinase 1 (PS6K), human epidermal growth factor receptor 2 (c-erbB-2), and carbonic anhydrase IX (CA9) was evaluated in 44 patients with prostate carcinoma treated with or without ADT, at biopsy time and after radical prostatectomy. PDGFR, VEGF-C, mToR, and PS6K expression was significantly reduced (p = 0.002, p = 0.035, p = 0.025, and p = 0.033, respectively) after ADT, whereas expression of EGFR, c-erbB-2, and CA9 was not influenced by ADT. In conclusion, targeting PDGFR, VEGF-C, mToR, or PS6K after ADT should be considered with precaution, as those targets can severely be altered or functionally deregulated by ADT.

Cyclin A1 modulates the expression of vascular endothelial growth factor and promotes hormone-dependent growth and angiogenesis of breast cancer

Alterations in cellular pathways related to both endocrine and vascular endothelial growth factors (VEGF) may contribute to breast cancer progression. Inhibition of the elevated levels of these pathways is associated with clinical benefits. However, molecular mechanisms by which endocrine-related pathways and VEGF signalling cooperatively promote breast cancer progression remain poorly understood. In the present study, we show that the A-type cyclin, cyclin A1, known for its important role in the initiation of leukemia and prostate cancer metastasis, is highly expressed in primary breast cancer specimens and metastatic lesions, in contrasting to its barely detectable expression in normal human breast tissues. There is a statistically significant correlation between cyclin A1 and VEGF expression in breast cancer specimens from two patient cohorts (p<0.01). Induction of cyclin A1 overexpression in breast cancer cell line MCF-7 results in an enhanced invasiveness and a concomitant increase in VEGF expression. In addition, there is a formation of protein–protein complexes between cyclin A1 and estrogen receptor ER-α cyclin A1 overexpression increases ER-α expression in MCF-7 and T47D cells. In mouse tumor xenograft models in which mice were implanted with MCF-7 cells that overexpressed cyclin A1 or control vector, cyclin A1 overexpression results in an increase in tumor growth and angiogenesis, which is coincident with an enhanced expression of VEGF, VEGFR1 and ER-α Our findings unravel a novel role for cyclin A1 in growth and progression of breast cancer, and suggest that multiple cellular pathways, including cell cycle regulators, angiogenesis and estrogen receptor signalling, may cooperatively contribute to breast cancer progression.

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.

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.

Differential expression of VEGF ligands and receptors in prostate cancer

BACKGROUND

Prostate cancer disseminates to regional lymph nodes, however the molecular mechanisms responsible for lymph node metastasis are poorly understood. The vascular endothelial growth factor (VEGF) ligand and receptor family have been implicated in the growth and spread of prostate cancer via activation of the blood vasculature and lymphatic systems. The purpose of this study was to comprehensively examine the expression pattern of VEGF ligands and receptors in the glandular epithelium, stroma, lymphatic vasculature and blood vessels in prostate cancer.

METHODS

The localization of VEGF-A, VEGF-C, VEGF-D, VEGF receptor (VEGFR)-1, VEGFR-2, and VEGFR-3 was examined in cancerous and adjacent benign prostate tissue from 52 subjects representing various grades of prostate cancer.

RESULTS

Except for VEGFR-2, extensive staining was observed for all ligands and receptors in the prostate specimens. In epithelial cells, VEGF-A and VEGFR-1 expression was higher in tumor tissue compared to benign tissue. VEGF-D and VEGFR-3 expression was significantly higher in benign tissue compared to tumor in the stroma and the endothelium of lymphatic and blood vessels. In addition, the frequency of lymphatic vessels, but not blood vessels, was lower in tumor tissue compared with benign tissue.

CONCLUSIONS

These results suggest that activation of VEGFR-1 by VEGF-A within the carcinoma, and activation of lymphatic endothelial cell VEGFR-3 by VEGF-D within the adjacent benign stroma may be important signaling mechanisms involved in the progression and subsequent metastatic spread of prostate cancer. Thus inhibition of these pathways may contribute to therapeutic strategies for the management of prostate cancer.

Small breast epithelial mucin tumor tissue expression is associated with increased risk of recurrence and death in triple-negative breast cancer patients

Background

Small breast epithelial mucin (SBEM) has been implicated in tumor genesis and micrometastasis in breast cancer. Triple-negative breast cancer (TNBC) was characterized by high incidence in young women,early relapse and a very poor prognosis. The aim of this study was to evaluate the association of SBEM expression in tissues of TNBC with disease-free survival (DFS) and overall survival (OS).

Methods

SBEM protein expression was detected in 87 available formalin-fixed paraffin-embedded (FFPE) tissue specimens from TNBC patients by means of immunohistochemistry (IHC). We analyzed the correlation between the SBEM protein expression and DFS and OS during a 5 year follow-up period, respectively. And a SBEM cut-off value of prognosis was established associated with DFS and OS. SBEM was analyzed against other risk factors in multivariate analysis.

Results

SBEM 3+ score was cut-off value of prognosis and significantly correlated with DFS (p = 0.000) and OS (p = 0.001) in TNBC patients. There was a marked associations (p <0.05) between SBEM 3+ score and tumor size, grade, node status, TNM stage and Ki67. Multivariate analysis showed that patients with SBEM 3+ represented a higher risk of recurrence and mortality than those with a lower SBEM expression (HR = 3.370 with p = 0.008 for DFS and HR = 4.185 with p = 0.004 for OS).

Conclusions

SBEM is an independent risk predictor and may offer utility as a prognostic marker in TNBC patients.

Virtual Slides

http://www.diagnosticpathology.diagnomx.eu/vs/1624613061936917

Impact of VEGF-C gene polymorphisms and environmental factors on oral cancer susceptibility in Taiwan

Background

Oral cancer, which is the fourth most common male cancer, is associated with environmental carcinogens in Taiwan. Vascular endothelial growth factor (VEGF)-C, an angiogenic/lymphangiogenic factor with high expression levels in tumor tissues, plays important roles in the development of several malignancies. This study was designed to examine associations of five VEGF-C gene polymorphisms with the susceptibility to and clinicopathological characteristics of oral squamous cell carcinoma.

Methodology/Principal Findings

Five single-nucleotide polymorphisms (SNPs) of VEGF-C were analyzed by a real-time polymerase chain reaction (PCR) in 470 male patients with oral cancer and 426 cancer-free controls. In this study, we found that the VEGF-C rs7664413 and rs2046463 polymorphisms were associated with oral-cancer susceptibility but not with any clinicopathological parameters. The GGACA or GACTG haplotype of five VEGF-C SNPs (rs3775194, rs11947611, rs1485766, rs7664413, and rs2046463) combined was also related to the risk of oral cancer. Among 611 male smokers, VEGF-C polymorphism carriers who also chewed betel quid were found to have a 14.5–24.2-fold risk of having oral cancer compared to the VEGF-C wild-type carrier who did not chew betel quid. Among 461 male betel-quid chewers, VEGF-C polymorphism carriers who also smoked had a 2.7–18.1-fold risk of having oral cancer compared to those who carried the wild type but did not smoke.

Conclusions

Our results suggest that the two SNPs of VEGF-C (rs7664413 and rs2046463) and either of two haplotypes of five SNPs combined have potential predictive significance in oral carcinogenesis. Gene-environmental interactions among VEGF-C polymorphisms, smoking, and betel-quid chewing might alter one's susceptibility to oral cancer.

Expression and significances of contactin-1 in human gastric cancer

Background. This study aimed at determining the relationship between vascular endothelial growth factor-C (VEGF-C), vascular endothelial growth factor receptor-3 (VEGFR-3), and contactin-1 (CNTN-1) expression in gastric cancer (GC). Methods. The expression level of CNTN-1 mRNA and CNTN-1 protein of 33 cases was determined using RT-PCR and Western Blot. And 105 cases were immunohistochemically examined for VEGF-C, VEGFR-3, and CNTN-1 expressions. Assessment of lymphatic vessel density (LVD) was also performed by D2-40 immunostaining. Then we analyzed the relationships between VEGF-C, VEGFR-3, and CNTN-1, as well as their correlations with clinicopathologic features, LVD, and survival time. Results. The positivity rate of VEGF-C, VEGFR-3, and CNTN-1 in primary tumor was 56.19%, 64.76%, and 58.09%. The expression of CNTN-1 significantly correlated with VEGF-C (P < 0.001) and VEGFR-3 (P < 0.001). All of them were closely related to TNM stage, lymphatic invasion, and lymph node involvement (P < 0.05). LVD was significantly correlated with VEGF-C (P = 0.001), VEGFR-3 (P = 0.011), and CNTN-1 expression (P < 0.001). VEGF-C, VEGFR-3, and CNTN-1 expression significantly associated with poorer prognosis (P < 0.001, P = 0.034, P = 0.012, resp.). Conclusion. CNTN-1 associated with VEGF-C and VEGFR-3 expression in GC. All of them correlated with lymphatic metastasis, which might play an important role in the lymphatic invasion via lymphangiogenesis pathway in GC.

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.

Prostate-specific membrane antigen can promote in vivo osseous metastasis of prostate cancer cells in mice

Reports remain insufficient on whether and how prostate-specific membrane antigen (PSMA) can influence in vivo osseous metastasis of prostate cancer (PCa). In the present study, the authors induced stable expression of PSMA in mouse PCa cell line RM-1. In vivo osseous metastasis was induced in 37 6-week-old female C57BL/6 mice weighing 22.45 ± 0.456 g. RM-1 cells were actively injected into the femoral bone cavity, leading to bilateral dissymmetry of bone density in the femoral bone. Tumor cells were also detected in bone tissue by pathological examination. The impact on bone density was demonstrated by the significant difference between animals injected with RM-PSMA cells (0.0738 ± 0.0185 g/cm²) and animals injected with RM-empty plasmid cells (0.0895 ± 0.0241 g/cm²). The lytic bone lesion of the RM-PSMA group (68.4%) was higher than that of the control group (27.8%). Immunohistochemistry showed that the expression of both vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) was distinctly higher in the RM-PSMA group than in the control group, while ELISA and Western blot assay indicated that VEGF and MMP-9 were higher in the RM-PSMA group compared to the control group (in vitro). Thus, the present study proposed and then confirmed for the first time that PSMA can promote in vivo osseous metastasis of PCa by increasing sclerotic destruction of PCa cells. Further analyses also suggested that PSMA functions positively on the invasive ability of RM-1 by increasing the expression of MMP-9 and VEGF by osseous metastases in vivo.

Cell-to-cell signaling influences the fate of prostate cancer stem cells and their potential to generate more aggressive tumors

An increasing number of malignancies has been shown to be initiated and propelled by small subpopulations of cancer stem cells (CSC). However, whether tumor aggressiveness is driven by CSC and by what extent this property may be relevant within the tumor mass is still unsettled. To address this issue, we isolated a rare tumor cell population on the basis of its CD44⁺CD24⁻ phenotype from the human androgen-independent prostate carcinoma cell line DU145 and established its CSC properties. The behavior of selected CSC was investigated with respect to the bulk DU145 cells. The injection of CSC in nude mice generated highly vascularized tumors infiltrating the adjacent tissues, showing high density of neuroendocrine cells and expressing low levels of E-cadherin and β-catenin as well as high levels of vimentin. On the contrary, when a comparable number of unsorted DU145 cells were injected the resulting tumors were less aggressive. To investigate the different features of tumors in vivo, the influence of differentiated tumor cells on CSC was examined in vitro by growing CSC in the absence or presence of conditioned medium from DU145 cells. CSC grown in permissive conditions differentiated into cell populations with features similar to those of cells held in aggressive tumors generated from CSC injection. Differently, conditioned medium induced CSC to differentiate into a cell phenotype comparable to cells of scarcely aggressive tumors originated from bulk DU145 cell injection. These findings show for the first time that CSC are able to generate differentiated cells expressing either highly or scarcely aggressive phenotype, thus influencing prostate cancer progression. The fate of CSC was determined by signals released from tumor environment. Moreover, using microarray analysis we selected some molecules which could be involved in this cell-to-cell signaling, hypothesizing their potential value for prognostic or therapeutic applications.

Expression of vascular endothelial growth factor-C in gastric carcinoma and the effect of its antisense gene transfection on the proliferation of human gastric cancer cell line SGC-7901

PURPOSE

The aim of this study was to investigate the relationship between the expression of vascular endothelial growth factor-C (VEGF-C) in gastric carcinoma and tumor lymphangiogenesis and to determine the effect of antisense-VEGF-C gene transfection on proliferation.

METHODS

Adjacent cancer tissues were collected from 72 gastric carcinoma cases and compared with 10 nongastric carcinoma tissues to detect the expression of VEGF-C and its messenger RNA (mRNA) and calculate the density of neonatal lymphatic microvessels. The in vitro-cultured gastric cancer cell line SGC-7901 was transfected with recombinant plasmid pCI-neo-anti VEGF-C. The expression in the transfected cells and the proliferation were determined.

RESULTS

The positive rate of VEGF-C mRNA in the lymph node metastasis tissues was 85.7% compared with negative controls (20%, P < .05). The density of lymphatic vessels in the metastasis group was 6.65 ± 1.57 compared with the negative group (3.75 ± 1.47, P < .05). Protein and mRNA of VEGF-C were reduced in transfected cells. Proliferation was inhibited as well.

CONCLUSIONS

VEGF-C can increase the invasiveness of gastric cancer and promote lymphangiogenesis in adjacent tissues. Transfection with antisense VEGF-C can reduce the expression of VEGF-C and inhibit the proliferation. VEGF-C can inhibit the tumor growth and reduce its metastasis and recurrence.

Conserved signaling through vascular endothelial growth (VEGF) receptor family members in murine lymphatic endothelial cells

Lymphatic vessels guide interstitial fluid, modulate immune responses by regulating leukocyte and antigen trafficking to lymph nodes, and in a cancer setting enable tumor cells to track to regional lymph nodes. The aim of the study was to determine whether primary murine lymphatic endothelial cells (mLECs) show conserved vascular endothelial growth factor (VEGF) signaling pathways with human LECs (hLECs). LECs were successfully isolated from murine dermis and prostate. Similar to hLECs, vascular endothelial growth factor (VEGF) family ligands activated MAPK and pAkt intracellular signaling pathways in mLECs. We describe a robust protocol for isolation of mLECs which, by harnessing the power of transgenic and knockout mouse models, will be a useful tool to study how LEC phenotype contributes to alterations in lymphatic vessel formation and function.

Experimental models to study lymphatic and blood vascular metastasis

As a model system for the understanding of human cancer, the mouse has proved immensely valuable. Indeed, studies of mouse models have helped to define the nature of cancer as a genetic disease and demonstrated the causal role of genetic events found in tumors. As an experimental platform, they have provided critical insight into the process of tumor metastasis in the lymphovascular system. Once viewed with skepticism, mouse models are now an integral arm of basic and clinical cancer research. The use of a genetically tractable organism that shares organ systems and an immense degree of genetic similarity to humans provides a means to examine multiple features of human disease. Mouse models enable development and testing of new approaches to disease prevention and treatment, identification of early diagnostic markers and novel therapeutic targets, and an understanding of the in vivo biology and genetics of tumor initiation, promotion, progression, and metastasis. This review summarizes recent mouse models for lymphangiogenesis and the process of lymphovascular metastasis, focusing on the use of the cornea as an experimental platform for lymphangiogenesis in inflammation and immunity, and on the use of molecular and viral vector mediated imaging and to identify and monitor lymph node metastases of prostate cancer.

The rate of polymyalgia rheumatica (PMR) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome in a clinic where primary care physicians are working in Japan

We analyzed the rate of polymyalgia rheumatica (PMR) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome, both characterized as seronegative inflammatory arthritis in elderly, in an outpatient unit where primary care physicians are working in Japan to better understand the epidemiological characteristics of the diseases in Japan. Consecutive outpatients who newly visited at Department of General Medicine, Asahikawa Medical University Hospital, Japan, between April 2004 and March 2010 were analyzed. Each parameter such as age, sex, diagnosis, and biochemical examination was investigated. During the 6 years, 10 or 3 patients were diagnosed as PMR or RS3PE syndrome, respectively. The patients with PMR were 7 women and 3 men, and the average age at diagnosis was 69. Out of all patients aged over 50 (n = 3,347), the rate of PMR was 0.22% in men or 0.36% in women, respectively. On the other hand, RS3PE syndrome was diagnosed in 3 men (76, 76, and 81 years old). The rate of patients with RS3PE syndrome was 0.09% among outpatients aged over 50 indicating that the rate of PMR in an outpatient clinic in Japan is not far from previous findings reported from western countries. When compared with PMR, the rate of RS3PE syndrome was approximately one-third, providing for the first time the rate of RS3PE syndrome when compared with PMR. These epidemilogical data might help us pick up the diseases in primary care setting in Japan.