Vascular frontiers without borders: multifaceted roles of platelet-derived growth factor (PDGF) in supporting postnatal angiogenesis and lymphangiogenesis

The inflammatory markers combined with CA125 may predict postoperative survival in endometrial cancer

BACKGROUND

Endometrial cancer (EC) has a high latency, making prognosis difficult to predict. Cancer antigen 125 (CA125) is not specific as a tumour marker for EC; however, complete blood count (CBC) inflammatory markers are associated with prognosis in various malignancies. Thus, this study investigated the value of CBC inflammatory markers combined with CA125 levels in predicting the prognosis of patients with EC.

METHODS

In this study, 517 patients with EC were recruited between January 2015 and January 2022, and clinical characteristics, CBC inflammatory markers, and CA125 levels were assessed. Differences in each index at different EC stages and the correlation between the index and EC stage were analysed, and the influence of the index on EC prognosis was evaluated.

RESULTS

Platelet distribution width (PDW) levels were significantly lower in patients with advanced EC than in those with early EC, whereas the systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and CA125 levels were significantly higher in patients with advanced EC (all P < 0.05). ROC curve and multivariate logistic regression analyses indicated that decreased PDW and increased CA125 levels were independent risk factors for EC staging progression. In addition, multivariate Cox regression analysis showed that the combination of low PDW and high CA125 (PDW + CA125 = 2) was an independent prognostic factor of survival in EC patients. Kaplan-Meier survival analysis indicated that patients with low PDW and high CA125 had worse overall survival.

CONCLUSIONS

The PDW and CA125 score may be an independent prognostic factor for postoperative overall survival in patients with EC and a useful marker for predicting the prognosis of these patients.

Lymphatic vasculature in ovarian cancer

Ovarian cancer (OVCA) is the second most common gynecological cancer and one of the leading causes of cancer related mortality among women. Recent studies suggest that among ovarian cancer patients at least 70% of the cases experience the involvement of lymph nodes and metastases through lymphatic vascular network. However, the impact of lymphatic system in the growth, spread and the evolution of ovarian cancer, its contribution towards the landscape of ovarian tissue resident immune cells and their metabolic responses is still a major knowledge gap. In this review first we present the epidemiological aspect of the OVCA, the lymphatic architecture of the ovary, we discuss the role of lymphatic circulation in regulation of ovarian tumor microenvironment, metabolic basis of the upregulation of lymphangiogenesis which is often observed during progression of ovarian metastasis and ascites development. Further we describe the implication of several mediators which influence both lymphatic vasculature as well as ovarian tumor microenvironment and conclude with several therapeutic strategies for targeting lymphatic vasculature in ovarian cancer progression in present day.

Angiogenin and Copper Crossing in Wound Healing

Angiogenesis plays a key role in the wound healing process, involving the migration, growth, and differentiation of endothelial cells. Angiogenesis is controlled by a strict balance of different factors, and among these, the angiogenin protein plays a relevant role. Angiogenin is a secreted protein member of the ribonuclease superfamily that is taken up by cells and translocated to the nucleus when the process of blood vessel formation has to be promoted. However, the chemical signaling that activates the protein, normally present in the plasma, and the transport pathways through which the protein enters the cell are still largely unclear. Copper is also an angiogenic factor that regulates angiogenin expression and participates in the activation of common signaling pathways. The interaction between angiogenin and copper could be a relevant mechanism in regulating the formation of new blood vessel pathways and paving the way to the development of new drugs for chronic non-healing wounds.

Nanomaterials for Angiogenesis in Skin Tissue Engineering

Damage to skin tissue, which causes the disorder of the patient's body homeostasis, threatens the patient's life and increases the personal and social treatment burden. Angiogenesis, a key step in the wound healing process, provides sufficient oxygen and nutrients to the wound area. However, traditional clinical interventions are not enough to stabilize the formation of the vascular system to support wound healing. Due to the unique properties and multiple functions of nanomaterials, it has made a major breakthrough in the application of medicine. Nanomaterials provide a more effective treatment to hasten the angiogenesis and wound healing, by stimulating fundamental factors in the vascular regeneration phase. In the present review article, the basic stages and molecular mechanisms of angiogenesis are analyzed, and the types, applications, and prospects of nanomaterials used in angiogenesis are detailed. Impact statement Wound healing (especially chronic wounds) is currently a clinically important issue. The long-term nonhealing of chronic wounds often plagues patients, medical systems, and causes huge losses to the social economy. There is currently no effective method of treating chronic wounds in the clinic. Angiogenesis is an important step in wound healing. Nanomaterials had properties that are not found in conventional materials, and they have been extensively studied in angiogenesis. This review article provides readers with the molecular mechanisms of angiogenesis and the types and applications of angiogenic nanomaterials, hoping to bring inspiration to overcome chronic wounds.

Noninvasive profiling of serum cytokines in breast cancer patients and clinicopathological characteristics

Cancers elicit an immune response by modifying the microenvironment. The immune system plays a pivotal role in cancer recognition and eradication. While the potential clinical value of infiltrating lymphocytes at the tumor site has been assessed in breast cancer, circulating cytokines – the molecules coordinating and fine-tuning immune response – are still poorly characterized.

Using two breast cancer cohorts (MicMa, n = 131, DCTB, n = 28) and the multiplex Luminex platform, we measured the levels of 27 cytokines in the serum of breast cancer patients prior to treatment. We investigated the cytokine levels in relation to clinicopathological characteristics and in perspective of the tumor infiltrating immune cells predicted from the bulk mRNA expression data.

Unsupervised clustering analysis of the serum cytokine levels in the MicMa cohort identified a cluster of pro-inflammatory, pro-angiogenic, and Th2-related cytokines which was associated with poor prognosis. Notably high levels of platelet derived growth factor BB (PDGF) reflected a more aggressive tumor phenotype and larger tumor size. A significant positive correlation between serum levels of interferon gamma-induced protein 10 (IP10) and its mRNA expression at the tumor site suggested that tumor-IP10-production may outflow to the bloodstream. High IP10 serum levels were associated with a worse prognosis. Finally, we found serum levels of both PDGF and IP10 associated with enrichment scores of specific tumor infiltrating immune cells.

Our study suggests that monitoring cytokine circulating levels in breast cancer could be used to characterize breast cancers and the immune composition of their microenvironment through readily available biological material.

Coculture of endothelial progenitor cells and mesenchymal stem cells enhanced their proliferation and angiogenesis through PDGF and Notch signaling

The beneficial effects of combined use of mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) on tissue repair and regeneration after injury have been demonstrated, but the underlying mechanism remains incompletely understood. This study aimed to investigate the effects of direct contact coculture of human bone marrow‐derived EPCs (hEPCs)/human bone marrow‐derived MSCs (hMSCs) on their proliferation and angiogenic capacities and the underlying mechanism. hEPCs and hMSCs were cocultured in a 2D mixed monolayer or a 3D transwell membrane cell‐to‐cell coculture system. Cell proliferation was determined by Cell Counting Kit‐8. Angiogenic capacity was evaluated by in vitro angiogenesis assay. Platelet‐derived growth factor‐BB (PDGF‐BB), PDGF receptor neutralizing antibody (AB‐PDGFR), and DAPT (a γ‐secretase inhibitor) were used to investigate PDGF and Notch signaling. Cell proliferation was significantly enhanced by hEPCs/hMSCs 3D‐coculture and PDGF‐BB treatment, but inhibited by AB‐PDGFR. Expression of cyclin D1, PDGFR, Notch1, and Hes1 was markedly enhanced by PDGF‐BB but inhibited by DAPT. In vitro angiogenesis assay showed that hEPCs/hMSCs coculture and PDGF‐BB significantly enhanced angiogenic capacity, whereas AB‐PDGFR significantly reduced the angiogenic capacity. PDGF‐BB increased the expression of kinase insert domain receptor (KDR, an endothelial marker) and activated Notch1 signaling in cocultured cells, while DAPT attenuated the promoting effect of PDGF‐BB on KDR expression of hEPCs/hMSCs coculture. hEPCs/hMSCs coculture enhanced their proliferation and angiogenic capacities. PDGF and Notch signaling pathways participated in the promoting effects of hEPCs/hMSCs coculture, and there was crosstalk between these two signaling pathways. Our findings should aid understanding of the mechanism of beneficial effects of hEPCs/hMSCs coculture.

Hyaluronan/RHAMM interactions in mesenchymal tumor pathogenesis: role of growth factors

Fibrosarcoma belongs to the sarcoma cancer group, which are spindle cell malignancies of mesenchymal origin, and owe their name to the predominant cell line that is present within the tumor. The extracellular matrix (ECM) is a complicated structure that surrounds and supports cells within tissues. Its main components are proteoglycans, collagens, glycoproteins, hyaluronan (HA), and several matrix-degrading enzymes. During cancer progression, significant changes can be observed in the structural and mechanical properties of ECM components. The ECM provides a physical scaffold to which tumor cells attach and migrate. Thus, it is required for key cellular events such as cell motility, adhesion, proliferation, invasion, and metastasis. Importantly, fibrosarcomas were shown to have a high content and turnover of ECM components including HA, proteoglycans, collagens, fibronectin, and laminin. In this review, we will focus on the HA component of fibrosarcoma ECM and critically discuss its role and involved mechanisms during fibrosarcoma pathogenesis.

Elevated Platelet-Derived Growth Factor AB/BB is Associated with a Lower Risk of Recurrent Vascular Events in Stroke Patients

Background

Platelet-derived growth factor (PDGF)-AB and BB have been shown to possess angiogenic properties in vivo, and decreased levels have been linked to plaque instability in atherosclerosis. Little work has been done to determine if PDGF is associated with outcomes after stroke, in particular cognitive outcomes. Therefore, in this sudy, we investigated the association between PDGFand both vascular and cognitive outcomes in a cohort of patients with recent nondisabling ischemic stroke.

Methods

Three hundred nine patients recruited within six-months of a transient ischemic attack or nondisabling ischemic stroke [modified Rankin Scale (mRS) ⩽ 3] were followed for up to five-years. Cox proportional-hazard regression analyses were performed to investigate the association of PDGF levels with the risk of death, recurrent vascular events, dependency, and incident dementia, while logistic regression analyses were performed to investigate the association of PDGF levels with the risk of significant cognitive decline. Significant cognitive decline was defined as: (a) a decline of cognitive status from no cognitive impairment or mild cognitive impairment with no dementia to moderate cognitive impairment with no dementia or (b) conversion to dementia.

Results

Patients (mean age 60 years) were mostly male (64%) and of Chinese ethnicity (85%) and had posterior circulation or lacunar infarcts (73%). In univariate analysis, PDGF was significantly associated with a lower risk of recurrent vascular events [hazard ratio (HR) 0·61; 95% confidence interval (CI) 0·44–0·84]. In multivariate analysis adjusting for treatment, PDGF was independently associated with a lower risk of recurrent vascular events (HR 0·62; 95% CI 0·46–0·85). PDGF levels were not associated with the risk of the other outcomes of interest.

Conclusions

Higher levels of PDGF-AB/BB were independently associated with a lower risk of recurrent vascular events in a cohort of convalescent nondisabled stroke patients. Our findings suggest that PDGF-AB/BB may potentially serve as a prognostic marker for outcomes pos- stroke and, if this result is validated in larger samples, a potential therapeutic target.

Application of peripheral-blood-derived endothelial progenitor cell for treating ischemia-reperfusion injury and infarction: a preclinical study in rat models

Background

Our aim was to explore the therapeutic effects of peripheral blood-derived endothelial progenitor cells (PB-EPC) in cardiac ischemia-reperfusion infarction models in rats and in in vitro culture systems.

Methods

Rat models of ischemia reperfusion and myocardial infarction were developed using male, Sprague–Dawley rats. Cardiomyocyte and endothelial cell cultures were also established. Therapeutic effects of PB-EPCs were examined in vivo and in vitro in both models. Rats underwent either cardiac ischemia-reperfusion (n = 40) or infarction (n = 56) surgeries and were transplanted with genetically modified EPCs. Treatment efficacy in the ischemia-reperfusion group was measured by infarct size, myocardial contraction velocity, and myeloperoxidase activity after transplantation. Cardiomyocyte survival and endothelial cell apoptosis were investigated in vitro. Vascular growth-associated protein expression and cardiac function were evaluated in the myocardial infarction group by western blot and echocardiography, respectively.

Results

Infarct size and myeloperoxidase activity were significantly decreased in the ischemia-reperfusion group, whereas myocardial contractility was significantly increased in the EPC and Tβ4 groups compared with that in the control group. In contrast, no differences were found between EPC + shRNA Tβ4 and control groups. Rates of cardiomyocyte survival and endothelial cell apoptosis were significantly higher and lower, respectively, in the EPC and Tβ4 groups than in the control group, whereas no differences were found between the EPC + shRNA Tβ4 and control group. Four weeks after myocardial infarction, cardiac function was significantly better in the EPC group than in the control group. Expressions of PDGF, VEGF, and Flk-1 were significantly higher in EPC group than in control group.

Conclusions

Study findings suggest that PB-EPCs are able to protect cardiomyocytes from ischemia-reperfusion or infarction-induced damage via a Tβ4-mediated mechanism. EPCs may also provide protection through increased expression of proteins involved in mediating vascular growth. Autologous peripheral-blood-derived EPCs are readily available for efficient therapeutic use without the concerns of graft rejection.

Lymphangiogenesis, myeloid cells and inflammation

The lymphatic system is essential for the maintenance of tissue fluid balance, immune surveillance and the absorption of fatty acids in the gastrointestinal tract. The lymphatic circulation is also a key player in disease processes such as cancer metastasis, lymphedema and various inflammatory disorders. With the identification of specific growth factors for lymphatic endothelial cells and markers that distinguish blood and lymphatic vessels, as well as the development of in vivo imaging technologies that provide new tools to examine the lymphatic drainage function in real time, many advancements have been made in lymphatic vascular research during the past few years. Despite these significant achievements, our understanding of the role of lymphatics in disease processes other than cancer metastasis is still rather limited. The current review will focus on the recent progress made in studies of lymphatics in inflammatory disorders.

Role of tumor-associated lymphatic endothelial cells in metastasis: a study of epithelial ovarian tumor in vitro

Tumor-associated lymphatic endothelial cells (TLEC) could play a key role in the process of tumor metastasis. The aim of this study was to investigate the effect of TLECs that were isolated from human epithelial ovarian tumor (EOT) on ovarian cancer cell line CAOV-3 in vitro. First, TLECs in EOT were detected by immunochemistry and flow cytometry, then marked by lymphatic endothelial cell (LEC) marker LYVE-1, isolated by magnetic beads, and cultured in vitro. The cells were identified by immunostaining of LEC markers LYVE-1, Prox-1, Podoplanin, VEGFR-3, and pan-endothelial cell marker CD31. TLECs from EOT can be detected, cultured, and identified in vitro successfully. The effects of TLECs on invasion and migration of CAOV-3 cells were investigated by 12-well Boyden chamber; the proliferation effect was studied by counting the Trypan blue exclusion cell number. Furthermore, changes in MMP-2/9 secreted by CAOV-3 cells treated with TLEC were shown using real-time PCR and zymography, and TIMP-1/2 was detected by real-time PCR. In vitro, TLECs can enhance invasion and migration of CAOV-3 cells, but have no significant effect on proliferation. It was clear that the expression of MMP-9 increased and TIMP-2 decreased in CAOV-3 cells treated by TLECs, and the increasing of MMP-9 was confirmed by zymography. TLECs from EOT can enhance migration and invasion of human ovarian carcinoma cell line in vitro, and the possible mechanism was through activation of MMP-9/TIMP-2.

A comparative study of carotid atherosclerotic plaque microvessel density and angiogenic growth factor expression in symptomatic versus asymptomatic patients

OBJECTIVE

A challenge facing clinicians is identifying patients with asymptomatic carotid disease at risk of plaque instability. We hypothesise that locally released angiogenic growth factors contribute to plaque instability.

METHODS

Carotid endarterectomy specimens from eight symptomatic and eight asymptomatic patients were interrogated for microvessel density and angiogenic growth factor expression histologically using immunofluorescence, and biochemically using quantitative real-time polymerase chain reaction (q-RT-PCR). Bio-Plex suspension array was used to assess circulating biomarkers in venous blood from the same patients and six healthy age-matched controls.

RESULTS

Immunofluorescence demonstrated significantly greater neovessel density in symptomatic plaques (P=0.010) with elevated expression of hepatocyte growth factor (HGF) (P=0.001) and its receptor MET (P=0.011) than in asymptomatic plaques. The q-RT-PCR demonstrated up-regulation of Endoglin (CD105), HGF (P=0.001) and MET (P=0.011) in the plaques of symptomatic versus asymptomatic patients. Bio-Plex suspension array demonstrated elevated HGF (P=0.002) serum levels in symptomatic versus asymptomatic patients and healthy controls, and decreased platelet-derived growth factor (PDGF) (P=0.036) serum levels in symptomatic versus asymptomatic patients.

CONCLUSION

Plaque instability may be mediated by HGF-induced formation of new microvessels, and decreased vessel stability resulting from decreased PDGF. Suspension array technology has the potential to identify circulating biomarkers that correlate with plaque rupture risk.

Changes in PDGF concentration in surgically treated colorectal carcinoma

PURPOSE

The aim of the present study was to asses the effect of tumor advancement, differentiation grade and surgery treatment on PDGF- AB level and platelet (PLT) count depending on the site of blood collection.

MATERIAL AND METHODS

The study included 38 patients submitted to surgical treatment due to diagnosis of colorectal cancer (CRC) without remote metastasis: G2- 20 patients and group G3- 18 patients. The control group consisted of 24 healthy subjects. In CRC patients the blood samples was collected three times: 1) before surgery, 2) intrasurgically and 3) 90 days after surgery. Serum PDGF- AB concentration was determined by ELISA- Kit reagents.

RESULTS

PDGF concentration in all the patients was several times higher than in the control group, irrespective of tumor differentiation grade and the site of blood collection. However the level of PDGF- AB in intraoperatively collected arterial blood and venous blood in group G3 (arterial blood- 379.9+/-12.1 ng/ml; venous blood- 398.4+/-13.2 ng/ml) was significantly higher than in group G2 (arterial blood- 169.4+/-88.6 ng/ml; venous blood- 194.2+/-84.0 ng/ml). No significant differences were observed between venous and arterial blood. No correlation was found between the PLT count and PDGF- AB concentration.

CONCLUSION

High blood PDGF- AB concentration in CRC patients but no significant positive correlation observed between the PLT count and PDGF-AB suggest its neoplastic origin beside PLT. Determination of this factor in blood serum may have an important implication in early diagnosis of CRC, which is the second most common malignant neoplasm with high recurrence rates.

Modeling lymphangiogenesis in a three-dimensional culture system

A lack of appropriate in vitro models of three-dimensional lymph vessel growth hampers the study of lymphangiogenesis. We developed a lymphatic ring assay--a potent, reproducible and quantifiable three-dimensional culture system for lymphatic endothelial cells that reproduces spreading of endothelial cells from a pre-existing vessel, cell proliferation, migration and differentiation into capillaries. In the assay, mouse thoracic duct fragments are embedded in a collagen gel, leading to the formation of lumen-containing lymphatic capillaries, which we assessed by electron microscopy and immunostaining. We developed a computerized method to quantify the lymphatic network. By applying this model to gene-deficient mice, we found evidence for involvement of the matrix metalloproteinase, MMP-2, in lymphangiogenesis. The lymphatic ring assay bridges the gap between two-dimensional in vitro models and in vivo models of lymphangiogenesis, can be used to exploit the potential of existing transgenic mouse models, and rapidly identify regulators of lymphangiogenesis.

Opinion: emerging mechanisms of tumour lymphangiogenesis and lymphatic metastasis

Malignant tumours can spread to lymph nodes through lymphatic vessels. Recent studies show that tumours produce a range of growth factors that directly or indirectly stimulate lymphatic vessel growth (lymphangiogenesis) and lymphatic metastasis. These findings indicate that tumour lymphangiogenesis, similar to haemangiogenesis, is a complex process that is regulated by multiple growth factors. Understanding the underlying mechanisms by which tumours induce lymphangiogenesis might provide important information for the therapeutic intervention of metastatic spread.