Biomarkers for anti-angiogenic therapy in cancer

PEG-conjugated bovine haemoglobin enhances efficiency of chemotherapeutic agent doxorubicin with alleviating DOX-induced splenocardiac toxicity in the breast cancer

Doxorubicin (DOX) is an effective chemotherapeutic agent widely used for cancer treatment. However, hypoxia in tumour tissue and obvious adverse effects particularly cardiotoxicity restricts the clinical usage of DOX. Our study is based on the co-administration of haemoglobin-based oxygen carriers (HBOCs) and DOX in a breast cancer model to investigate HBOCs' ability to enhance chemotherapeutic effectiveness and its capabilities to alleviate the side effects induced by DOX. In an in-vitro study, the results suggested the cytotoxicity of DOX was significantly improved when combined with HBOCs in a hypoxic environment, and produced more γ-H2AX indicating higher DNA damage than free DOX did. Compared with administration of free DOX, combined therapy exhibited a stronger tumour suppressive effect in an in-vivo study. Further mechanism studies showed that the expression of various proteins such as hypoxia-inducible factor-1α (HIF-1α), CD31, CD34, and vascular endothelial growth factor (VEGF) in tumour tissues was also significantly reduced in the combined treatment group. In addition, HBOCs can significantly reduce the splenocardiac toxicity induced by DOX, according to the results of the haematoxylin and eosin (H&E) staining and histological investigation. This study suggested that PEG-conjugated bovine haemoglobin may not only reduce the hypoxia in tumours and increase the efficiency of chemotherapeutic agent DOX, but also alleviate the irreversible heart toxicity caused by DOX-inducted splenocardiac dysregulation.

Cediranib in Combination with Olaparib in Patients without a Germline BRCA1/2 Mutation and with Recurrent Platinum-Resistant Ovarian Cancer: Phase IIb CONCERTO Trial

PURPOSE

The efficacy, safety, and tolerability of cediranib plus olaparib (cedi/ola) were investigated in patients with nongermline-BRCA-mutated (non-gBRCAm) platinum-resistant recurrent ovarian cancer.

PATIENTS AND METHODS

PARP inhibitor-naïve women aged ≥18 years with platinum-resistant non-gBRCAm ovarian cancer, ECOG performance status of 0-2, and ≥3 prior lines of therapy received cediranib 30 mg once daily plus olaparib 200 mg twice daily in this single-arm, multicenter, phase IIb trial. The primary endpoint was objective response rate (ORR) by independent central review (ICR) using RECIST 1.1. Progression-free survival (PFS), overall survival (OS), and safety and tolerability were also examined.

RESULTS

Sixty patients received cedi/ola, all of whom had confirmed non-gBRCAm status. Patients had received a median of four lines of chemotherapy; most (88.3%) had received prior bevacizumab. ORR by ICR was 15.3%, median PFS was 5.1 months, and median OS was 13.2 months. Forty-four (73.3%) patients reported a grade ≥3 adverse event (AE), with one patient experiencing a grade 5 AE (sepsis), considered unrelated to the study treatment. Dose interruptions, reductions, and discontinuations due to AEs occurred in 55.0%, 18.3%, and 18.3% of patients, respectively. Patients with high global loss of heterozygosity (gLOH) had ORR of 26.7% [4/15; 95% confidence interval (CI), 7.8-55.1], while ORR was 12.5% (4/32; 95% CI, 3.5-29.0) in the low gLOH group.

CONCLUSIONS

Clinical activity was shown for the cedi/ola combination in heavily pretreated, non-gBRCAm, platinum-resistant patients with ovarian cancer despite failing to meet the target ORR of 20%, highlighting a need for further biomarker studies.

Aptamer grafted nanoparticle as targeted therapeutic tool for the treatment of breast cancer

Breast carcinomas repeat their number and grow exponentially making it extremely frequent malignancy among women. Approximately, 70-80% of early diagnosed or non-metastatic conditions are treatable while the metastatic cases are considered ineffective to treat with current ample amount of therapy. Target based anti-cancer treatment has been in the limelight for decades and is perceived significant consideration of scientists. Aptamers are the 'coming of age' therapeutic approach, selected using an appropriate tool from the library of sequences. Aptamers are non-immunogenic, stable, and high-affinity ligand which are poised to reach the clinical benchmark. With the heed in nanoparticle application, the delivery of aptamer to the specific site could be enhanced which also protects them from nuclease degradation. Moreover, nanoparticles due to robust structure, high drug entrapment, and modifiable release of cargo could serve as a successful candidate in the treatment of breast carcinoma. This review would showcase the method and modified method of selection of aptamers, aptamers that were able to make its way towards clinical trial and their targetability and selectivity towards breast cancers. The appropriate usage of aptamer-based biosensor in breast cancer diagnosis have also been discussed.

Anti-vascular endothelial growth factor therapy in breast cancer: Molecular pathway, potential targets, and current treatment strategies

As the highest incidence of female malignancy, breast cancer is likewise the leading cause of cancer-related deaths. The development of cancer relies on neo-vascularization, which provides sufficient nutrition and oxygen, and supplies a pathway for distant metastasis. Angiogenesis represents the formation of new blood vessels, and is a principal pathogenetic action in breast cancer. Vascular endothelial growth factor (VEGF) is a major angiogenesis regulator that modulates the maintenance and function of mature vascular networks. Therefore, the VEGF pathway is a promising oncotherapeutic target. This review elaborates an update on the prognostic value of VEGF in breast cancer, summarizes clinical experience and lessons of anti-VEGF therapeutics, meanwhile, provides an overview of biomarkers that predict the effectiveness of anti-angiogenic treatment.

Cediranib, an inhibitor of vascular endothelial growth factor receptor kinases, inhibits proliferation and invasion of prostate adenocarcinoma cells

Prostate Cancer is the second cause of cancer-related death in men and development of metastatic castration-resistant prostate cancer (mCRPC) is the major reason for its high mortality rate. Despite various treatments, all patients succumb to resistant disease, suggesting that there is a pressing need for novel and more efficacious treatments. Members of the vascular endothelial growth factor (VEGF) family play key roles in the tumorigenesis of mCRPC, indicating that VEGF-targeted therapies may have potential anti-tumor efficacy in this malignancy. However, due to compensatory activation of other family members, clinical trials with single-targeted VEGF inhibitors were discouraging. Here, we determined the anti-neoplastic activity of Cediranib, a pan-VEGF receptor inhibitor, in the mCRPC cell lines. Anti-growth effects of Cediranib were studied by MTT and BrdU cell proliferation assays and crystal violet staining. Annexin V/PI, radiation therapy and cell motility assays were carried out to examine the effects of Cediranib on apoptosis, radio-sensitivity and cell motility. Quantitative reverse transcription-PCR (qRT-PCR) and Western blot analyses were conducted to determine the molecular mechanisms underlying the anti-tumor activity of Cediranib. Cediranib decreased cell viability and induced apoptosis via inhibition of the anti-apoptotic proteins. Combination with Cediranib synergistically increased Docetaxel sensitivity and potentiated the effects of radiation therapy. Furthermore, Cediranib impaired cell motility via decrease in the expression of the epithelial-to-mesenchymal transition markers. These findings suggest that Cediranib may have anti-tumor activity in mCRPC cells and warrant further investigation on the therapeutic activity of this pan-VEGF receptor inhibitor in mCRPC.

Angiogenesis in Breast Cancer Progression, Diagnosis, and Treatment

Angiogenesis is a significant event in a wide range of healthy and diseased conditions. This process frequently involves vasodilation and an increase in vascular permeability. Numerous players referred to as angiogenic factors, work in tandem to facilitate the outgrowth of endothelial cells (EC) and the consequent vascularity. Conversely, angiogenic factors could also feature in pathological conditions. Angiogenesis is a critical factor in the development of tumors and metastases in numerous cancers. An increased level of angiogenesis is associated with decreased survival in breast cancer patients. Therefore, a good understanding of the angiogenic mechanism holds a promise of providing effective treatments for breast cancer progression, thereby enhancing patients' survival. Disrupting the initiation and progression of this process by targeting angiogenic factors such as vascular endothelial growth factor (Vegf)-one of the most potent member of the VEGF family- or by targeting transcription factors, such as Hypoxia-Inducible Factors (HIFs) that act as angiogenic regulators, have been considered potential treatment options for several types of cancers. The objective of this review is to highlight the mechanism of angiogenesis in diseases, specifically its role in the progression of malignancy in breast cancer, as well as to highlight the undergoing research in the development of angiogenesis-targeting therapies.

In silico mouse study identifies tumour growth kinetics as biomarkers for the outcome of anti-angiogenic treatment

Angiogenesis is a crucial step in tumour progression, as this process allows tumours to recruit new blood vessels and obtain oxygen and nutrients to sustain growth. Therefore, inhibiting angiogenesis remains a viable strategy for cancer therapy. However, anti-angiogenic therapy has not proved to be effective in reducing tumour growth across a wide range of tumours, and no reliable predictive biomarkers have been found to determine the efficacy of anti-angiogenic treatment. Using our previously established computational model of tumour-bearing mice, we sought to determine whether tumour growth kinetic parameters could be used to predict the outcome of anti-angiogenic treatment. A model trained with datasets from six in vivo mice studies was used to generate a randomized in silico tumour-bearing mouse population. We analysed tumour growth in untreated mice (control) and mice treated with an anti-angiogenic agent and determined the Kaplan–Meier survival estimates based on simulated tumour volume data. We found that the ratio between two kinetic parameters, k₀ and k₁, which characterize the tumour's exponential and linear growth rates, as well as k₁ alone, can be used as prognostic biomarkers of the population survival outcome. Our work demonstrates a robust, quantitative approach for identifying tumour growth kinetic parameters as prognostic biomarkers and serves as a template that can be used to identify other biomarkers for anti-angiogenic treatment.

Tyrosine Kinase Inhibitor-Induced Hypertension: Role of Hypertension as a Biomarker in Cancer Treatment

:

Cancer treatment is an area of continuous improvement. Therapy is becoming more targeted and the use of anti-angiogenic agents in multiple cancers, specifically tyrosine kinase inhibitors (TKIs), has demonstrated prolonged survival outcomes compared with previous drugs. Therefore, they have become a well-established part of the treatment.

:

Despite good results, there is a broad range of moderate to severe adverse effects associated with treatment. Hypertension (HTN) is one of the most frequent adverse effects and has been associated with favourable outcomes (in terms of cancer treatment) of TKI treatment.

:

High blood pressure is considered a class effect of TKI treatment, although the mechanisms have not been fully described. Three current hypotheses of TKI-associated HTN are highlighted in this narrative review. These include nitric oxide decrease, a change in endothelin-1 levels and capillary rarefaction.

:

Several studies have investigated HTN as a potential biomarker of TKI efficacy. HTN is easy to measure and adding this factor to prognostic models has been shown to improve specificity. HTN may become a potential biomarker in clinical practice involving treating advanced cancers. However, data are currently limited by the number of studies and knowledge of the mechanism of action.

The roles and role-players in thyroid cancer angiogenesis

Thyroid cancer is the most prevalent endocrine cancer worldwide. Angiogenesis, the formation of new blood vessels, plays a pivotal role in the development and progression of tumors. Over the past years, cancer research has focused on the ability of tumors to induce newly formed blood vessel, because tumor growth and the process of cancer metastasis mainly depends on angiogenesis. Tumor neovascularization occurs following the imbalance between pro-angiogenic and anti-angiogenic factors until the tumor switches to an angiogenic phenotype. A number of signaling factors and receptors that are implicated in the regulation of angiogenesis have been identified and characterized; most notably, the vascular endothelial growth factors (VEGFs) family and their receptors, which are the main pro-angiogenic molecules during early development and in pathological conditions such as cancer. Although thyroid is a highly vascularized organ, angiogenic switch in tumors of this organ leads to the formation of a vast network of blood vessels that favors the dissemination of tumor cells to distant organs and results in deterioration of patient conditions. Accordingly, the identification of key angiogenic biomarkers for thyroid cancer can facilitate diagnosis, prognosis and clinical decision-making and also may help to discover targeting factors for effective cancer therapy as well as monitoring response to therapy. Hence, the main purposes of this review are to summarize the types and mechanisms of angiogenesis emphasizing the prominent factors implicated in thyroid cancer angiogenesis.

The impact of tumor receptor heterogeneity on the response to anti-angiogenic cancer treatment

Multiple promoters and inhibitors mediate angiogenesis, the formation of new blood vessels, and these factors represent potential targets for impeding vessel growth in tumors. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor targeted in anti-angiogenic cancer therapies. In addition, thrombospondin-1 (TSP1) is a major endogenous inhibitor of angiogenesis, and TSP1 mimetics are being developed as an alternative type of anti-angiogenic agent. The combination of bevacizumab, an anti-VEGF agent, and ABT-510, a TSP1 mimetic, has been tested in clinical trials to treat advanced solid tumors. However, the patients' responses are highly variable and show disappointing outcomes. To obtain mechanistic insight into the effects of this combination anti-angiogenic therapy, we have constructed a novel whole-body systems biology model including the VEGF and TSP1 reaction networks. Using this molecular-detailed model, we investigated how the combination anti-angiogenic therapy changes the amounts of pro-angiogenic and anti-angiogenic complexes in cancer patients. We particularly focus on answering the question of how the effect of the combination therapy is influenced by tumor receptor expression, one aspect of patient-to-patient variability. Overall, this model complements the clinical administration of combination anti-angiogenic therapy, highlights the role of tumor receptor variability in the heterogeneous responses to anti-angiogenic therapy, and identifies the tumor receptor profiles that correlate with a high likelihood of a positive response to the combination therapy. Our model provides novel understanding of the VEGF-TSP1 balance in cancer patients at the systems-level and could be further used to optimize combination anti-angiogenic therapy.

Tumor-associated Macrophages and Neuroendocrine Differentiation Decrease the Efficacy of Bevacizumab Plus Chemotherapy in Patients With Advanced Colorectal Cancer

BACKGROUND

In the present study, we investigated the prognostic and predictive role of neuroendocrine differentiation (NED) and tumor-associated macrophage (TAM) infiltration in tumor tissue from patients with advanced colorectal cancer who had received bevacizumab plus chemotherapy.

PATIENTS AND METHODS

A total of 123 consecutive patients with advanced colorectal cancer who had received bevacizumab plus irinotecan/oxaliplatin-based combination chemotherapy were included in the present study. In addition to the clinicopathologic parameters, the presence of NED and the level of TAM infiltration were studied as covariates for survival analysis.

RESULTS

The median patient age was 57 years (range, 30-76 years). The chemotherapy backbone was FOLFIRI (folinic acid, 5-fluorouracil, irinotecan) for 75% of the patients. Univariate analysis showed that only NED and TAM infiltration were significant predictive factors for progression-free survival. Left-sided tumors and low TAM infiltration were favorable factors for overall survival on univariate analysis. However, the TAM level was the only independent prognostic factor for overall survival (hazard ratio, 0.301; 95% confidence interval, 0.102-0.892).

CONCLUSION

Our results suggest that increased TAM infiltration in tumor tissue and NED could decrease the efficacy of bevacizumab plus combination chemotherapy in patients with advanced colorectal cancer. TAM infiltration in the tumor tissue could be used as a biomarker in patients with advanced colorectal cancer receiving bevacizumab plus chemotherapy.

Enhancer of zeste homolog 2 (EZH2) regulates tumor angiogenesis and predicts recurrence and prognosis of intrahepatic cholangiocarcinoma

BACKGROUND

Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of the polycomb repressive complex 2 (PRC2) and regulates tumor malignancy by gene silencing via histone methylation. In this study we investigate the role of EZH2 in angiogenesis of intrahepatic cholangiocarcinoma (ICC).

METHODS

The influence of EZH2 on tumor angiogenesis was examined by bioinformatics analysis of a public database. We also assessed the correlation between EZH2 and vasohibin 1 (VASH1) expression in 47 patients with ICC by immunohistochemical (IHC) staining and in vitro gene silencing assays. The prognostic significance of EZH2 and VASH1 expression by IHC was also examined in the ICC cohort.

RESULTS

Bioinformatics analysis showed that EZH2 was associated with several angiogenesis gene sets in the public database. EZH2 suppressed VASH1 expression in in vitro assays and IHC studies. EZH2-high/VASH1-low status was independently associated with poor disease-free survival (P = 0.019) and poor overall survival (P = 0.0055).

CONCLUSION

The current study demonstrated that high EZH2 expression was associated with activation of tumor angiogenesis, and activation of the EZH2-mediated angiogenesis pathway predicted the prognosis of patients with ICC.

Characterizing Glioblastoma Heterogeneity via Single-Cell Receptor Quantification

Dysregulation of tyrosine kinase receptor (RTK) signaling pathways play important roles in glioblastoma (GBM). However, therapies targeting these signaling pathways have not been successful, partially because of drug resistance. Increasing evidence suggests that tumor heterogeneity, more specifically, GBM-associated stem and endothelial cell heterogeneity, may contribute to drug resistance. In this perspective article, we introduce a high-throughput, quantitative approach to profile plasma membrane RTKs on single cells. First, we review the roles of RTKs in cancer. Then, we discuss the sources of cell heterogeneity in GBM, providing context to the key cells directing resistance to drugs. Finally, we present our provisionally patented qFlow cytometry approach, and report results of a "proof of concept" patient-derived xenograft GBM study.

Serum MMP-2 as a potential predictive marker for papillary thyroid carcinoma

OBJECTIVE

The prevalence of papillary thyroid carcinoma (PTC) is rising rapidly. However, there are no reliable serum biomarkers for PTC. This study aimed to investigate the validity of preoperative serum matrix metalloproteinase-2 (MMP-2) as a biomarker for predicting prognosis of PTC after total or partial thyroidectomy.

METHODS

Male patients with PTC or a benign thyroid nodule (BTN) and healthy controls (HCs) were retrospectively included. Receiver operating characteristic (ROC) curves were constructed to evaluate the performance of preoperative serum MMP-2 in diagnosing PTC, predicting lymph node metastasis (LNM), and predicting structurally persistent/recurrent disease (SPRD). Multivariate logistic regression and Cox regression were applied to identify independent risk factors for SPRD.

RESULTS

The preoperative serum MMP-2 concentration in the PTC group was higher than those in BTN and HC groups. The concentration of postoperative serum MMP-2 decreased in comparison with pre-operation. ROC curves showed that serum MMP-2 could differentially diagnose PTC from BTN at the cutoff value of 86.30 ng/ml with an area under the curve (AUC) of 0.905 and could predict central LNM (CLNM) at the cutoff value of 101.55 ng/ml with an AUC of 0.711. Serum MMP-2 ≥101.55 ng/ml, age ≥45 years, and advanced TNM stage were independent risk factors for CLNM. Patients with SPRD had a higher median MMP-2 level (149.22 ng/ml) than patients without SPRD (104.55 ng/ml). Serum MMP-2 at the cutoff value of 144.04 ng/ml could predict SPRD in PTC patients with an AUC of 0.803. Advanced TNM stage and serum MMP-2 ≥144.04 ng/ml were independent risk factors for SPRD. Patients with serum MMP-2 ≥144.04 ng/ml had a worse clinical outcome than those with MMP-2 <144.04 ng/ml.

CONCLUSION

Preoperative serum MMP-2 may serve as a biomarker for diagnosing PTC and a predictive indicator for LNM and SPRD in male patients with PTC.

Treatment response assessment with (R)-[11CPAQ PET in the MMTV-PyMT mouse model of breast cancer

Background

The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[¹¹C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models.

Methods

MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[¹¹C]PAQ PET as standardized uptake value (SUV)_mean, SUV_max relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[¹¹C]PAQ radiotracer uptake and therapy response biomarkers.

Results

The (R)-[¹¹C]PAQ SUV_max in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p < 0.0005 and p < 0.003, respectively). No significant change was observed in the PTX monotherapy group. There was a significant difference in the SUV_max change between the VEH group and B20-4.1.1/PTX combinational group, as well as between the VEH group and the B20-4.1.1 monotherapy group (p < 0.05). MRI revealed significant decreases in TV in the B20-4.1.1/PTX treatment group (p < 0.005) but not the other therapy groups. A positive trend was observed between the (R)-[¹¹C]PAQ SUV_max change and TV reduction in the B20-4.1.1/PTX group. Statistical testing showed a significant difference in the blood vessel density between the B20-4.1.1/PTX combinational group and the VEH group (p < 0.05) but no significant difference in the Ki67 positive signal between treatment groups.

Conclusions

The results of this study are promising. However, additional studies are necessary before (R)-[¹¹C]PAQ can be approved as a predictive radiotracer for cancer therapy response.

Mechanistic modeling quantifies the influence of tumor growth kinetics on the response to anti-angiogenic treatment

Tumors exploit angiogenesis, the formation of new blood vessels from pre-existing vasculature, in order to obtain nutrients required for continued growth and proliferation. Targeting factors that regulate angiogenesis, including the potent promoter vascular endothelial growth factor (VEGF), is therefore an attractive strategy for inhibiting tumor growth. Computational modeling can be used to identify tumor-specific properties that influence the response to anti-angiogenic strategies. Here, we build on our previous systems biology model of VEGF transport and kinetics in tumor-bearing mice to include a tumor compartment whose volume depends on the “angiogenic signal” produced when VEGF binds to its receptors on tumor endothelial cells. We trained and validated the model using published in vivo measurements of xenograft tumor volume, producing a model that accurately predicts the tumor’s response to anti-angiogenic treatment. We applied the model to investigate how tumor growth kinetics influence the response to anti-angiogenic treatment targeting VEGF. Based on multivariate regression analysis, we found that certain intrinsic kinetic parameters that characterize the growth of tumors could successfully predict response to anti-VEGF treatment, the reduction in tumor volume. Lastly, we use the trained model to predict the response to anti-VEGF therapy for tumors expressing different levels of VEGF receptors. The model predicts that certain tumors are more sensitive to treatment than others, and the response to treatment shows a nonlinear dependence on the VEGF receptor expression. Overall, this model is a useful tool for predicting how tumors will respond to anti-VEGF treatment, and it complements pre-clinical in vivo mouse studies.

One hallmark of cancer is angiogenesis, the formation of new blood capillaries from pre-existing vessels. Angiogenesis promotes tumor growth by enabling the tumor to obtain oxygen and nutrients from the surrounding microenvironment. Cancer drugs that inhibit angiogenesis ("anti-angiogenic therapies") have focused on inhibiting proteins that promote the growth of new blood vessels. The response to anti-angiogenic therapy is highly variable, and some tumors do not respond at all. Therefore, identifying a biomarker that predicts how specific tumors will respond would be extremely valuable. This work uses a computational model of tumor-bearing mice to investigate the response to anti-angiogenic treatment that targets the potent promoter of angiogenesis, vascular endothelial growth factor (VEGF), and how the response is influenced by tumor growth kinetics. We show that certain properties of tumor growth can be used to predict how much the tumor volume will be reduced upon administration of an anti-VEGF drug. This work identifies tumor growth parameters that may be reliable biomarkers for predicting how tumors will respond to anti-VEGF therapy. Our computational model generates novel, testable hypotheses and nicely complements pre-clinical studies of anti-angiogenic therapeutics.

Hypertension Caused by Lenvatinib and Everolimus in the Treatment of Metastatic Renal Cell Carcinoma

Multikinase inhibitors (MKI) and mammalian target of rapamycin (mTOR) inhibitors prolong progression-free (PFS) and overall survival (OS) in the treatment of metastatic renal cell carcinoma (mRCC) by reducing angiogenesis and tumor growth. In this regard, the MKI lenvatinib and the mTOR inhibitor everolimus proved effective when applied alone, but more effective when they were administered combined. Recently, both drugs were included in clinical trials, resulting in international clinical guidelines for the treatment of mRCC. In May 2016, lenvatinib was approved by the American Food and Drug Administration (FDA) for the use in combination with everolimus, as treatment of advanced renal cell carcinoma following one prior antiangiogenic therapy. A major problem of treating mRCC with lenvatinib and everolimus is the serious adverse event (AE) of arterial hypertension. During the treatment with everolimus and lenvatinib combined, 42% of the patients developed hypertension, while 10% of the patients treated with everolimus alone and 48% of the of the lenvatinib only treated patients developed hypertension. Lenvatinib carries warnings and precautions for hypertension, cardiac failure, and other adverse events. Therefore, careful monitoring of the patients is necessary.

Revision of the concept of anti-angiogenesis and its applications in tumor treatment

Anti-angiogenesis therapy, by blocking formation of new blood vessels in tumors, is the standard-of-care therapy for various cancer types. The classic concept of anti-angiogenesis is expected to turn a tumor into a "dormant" disease. However, the combination of anti-angiogenesis agents with conventional therapeutics has generally produced only modest survival benefits for cancer patients in clinical trials. Therefore, the concept and applications of anti-angiogenesis have evolved dramatically along with lessons learned from recent clinical experience. In this article, we will discuss the revised concept of anti-angiogenesis therapy and the applications of anti-angiogenesis drugs, and focus particularly on how to utilize current anti-angiogenesis agents and develop new approaches to provide more benefits to patients with cancer.

The Adverse Effect of Hypertension in the Treatment of Thyroid Cancer with Multi-Kinase Inhibitors

The treatment of thyroid cancer has promising prospects, mostly through the use of surgical or radioactive iodine therapy. However, some thyroid cancers, such as progressive radioactive iodine-refractory differentiated thyroid carcinoma, are not remediable with conventional types of treatment. In these cases, a treatment regimen with multi-kinase inhibitors is advisable. Unfortunately, clinical trials have shown a large number of patients, treated with multi-kinase inhibitors, being adversely affected by hypertension. This means that treatment of thyroid cancer with multi-kinase inhibitors prolongs progression-free and overall survival of patients, but a large number of patients experience hypertension as an adverse effect of the treatment. Whether the prolonged lifetime is sufficient to develop sequelae from hypertension is unclear, but late-stage cancer patients often have additional diseases, which can be complicated by the presence of hypertension. Since the exact mechanisms of the rise of hypertension in these patients are still unknown, the only available strategy is treating the symptoms. More studies determining the pathogenesis of hypertension as a side effect to cancer treatment as well as outcomes of dose management of cancer drugs are necessary to improve future therapy options for hypertension as an adverse effect to cancer therapy with multi-kinase inhibitors.

Effects and Side Effects of Using Sorafenib and Sunitinib in the Treatment of Metastatic Renal Cell Carcinoma

In recent years, targeted therapies have proven beneficial in terms of progression-free survival (PFS) and overall survival (OS) in the treatment of metastatic renal cell carcinoma (mRCC). The tyrosine kinase inhibitors (TKIs) sorafenib and sunitinib are included in international clinical guidelines as first-line and second-line therapy in mRCC. Hypertension is an adverse effect of these drugs and the degree of hypertension associates with the anti-tumour effect. Studies have compared newer targeted drugs to sorafenib and sunitinib in terms of PFS, OS, quality of life and safety profiles. Phase III studies presented promising response rates and acceptable safety profiles of axitinib and tivozanib compared to sorafenib, and a phase II study reported greater efficacy using a combination of bevacizumab and IFN-α compared to sunitinib. Treatment with nintedanib exhibited a notably low prevalence of hypertension compared to sunitinib. The use of sorafenib and sunitinib are challenged by new drugs, but do not appear likely to be substituted in the near future. To clarify whether newer targeted drugs should replace sorafenib and sunitinib, more research is needed. This manuscript reviews the current utility and adverse effects of sorafenib and sunitinib and newer targeted therapies in the treatment of mRCC.

Aptamer-functionalized hybrid nanoparticle for the treatment of breast cancer

PURPOSE

Resistance to chemotherapeutic agents such as doxorubicin is a major reason for cancer treatment failure. At present the treatment option for metastatic breast cancer is very poor. Therefore, development of an effective therapeutic strategy to circumvent MDR of metastatic breast cancer is highly anticipated. The MDR of metastatic breast cancer cells was accompanied with the overexpression of P-gp transporter. Even though the overexpression of P-gp could be minimized by silencing with siRNA, the question is how they can be selectively targeted to the cancer cells. We propose that aptamer surface labeling of the nanoparticles could enhance the selectively delivery of p-gp siRNA into the metastatic breast cancer cells. Our hypothesis is that conjugating nanoparticles with a cancer cell specific aptamer should allow selective delivery of therapeutic drugs to tumor cells leading to enhanced cellular toxicity and antitumor effect as compared to unconjugated nanoparticles. The primary objective of this study is to develop a targeted nanocarrier delivery system for siRNA into breast cancer cells.

DESIGN METHODS

For targeted delivery, Aptamer A6 has been used which can bind to Her-2 receptors on breast cancer cells. For aptamer binding to particle surface, maleimide-terminated PEG-DSPE (Mal-PEG) was incorporated into the nanoparticles. Initially, three blank hybrid nanoparticles (i.e. F21, F31, and F40) out of nine different formulations prepared by high pressure homogenization (HPH) using different amount of DOTAP, cholesterol, PLGA or PLGA-PEG and Mal-PEG were chosen. Then protamine sulfate-condensed GAPDH siRNA (TRITC conjugated; red) or P-gp siRNA was encapsulated into those nanoparticles. Finally, the particles were incubated with aptamer A6 (FITC conjugated; green) for surface labeling.

RESULTS

Aptamer labeled-nanoparticles having PLGA are smaller in size than those having PLGA-PEG. Surface charge was reduced when the particles were labeled with aptamer. Cell transfection was increased significantly in Her-2 (+) SKBR-3 and 4T1-R cells but not in Her-2 poorly expressed MDA MB-231 and MCF-7 cells. The knockdown of P-gp was increased significantly when the particles were labeled with aptamer. No significant cellular toxicity was observed for any of these formulations.

CONCLUSION

This preliminary study concludes that aptamer-functionalized hybrid nanoparticles could be used to deliver P-gp targeted siRNA into the breast cancer cells to overcome chemoresistance.

Limited Tumor Tissue Drug Penetration Contributes to Primary Resistance against Angiogenesis Inhibitors

Resistance mechanisms against antiangiogenic drugs are unclear. Here, we correlated the antitumor and antivascular properties of five different antiangiogenic receptor tyrosine kinase inhibitors (RTKIs) (motesanib, pazopanib, sorafenib, sunitinib, vatalanib) with their intratumoral distribution data obtained by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). In the first mouse model, only sunitinib exhibited broad-spectrum antivascular and antitumor activities by simultaneously suppressing vascular endothelial growth factor receptor-2 (VEGFR2) and desmin expression, and by increasing intratumoral hypoxia and inhibiting both tumor growth and vascularisation significantly. Importantly, the highest and most homogeneous intratumoral drug concentrations have been found in sunitinib-treated animals. In another animal model, where - in contrast to the first model - vatalanib was detectable at homogeneously high intratumoral concentrations, the drug significantly reduced tumor growth and angiogenesis. In conclusion, the tumor tissue penetration and thus the antiangiogenic and antitumor potential of antiangiogenic RTKIs vary among the tumor models and our study demonstrates the potential of MALDI-MSI to predict the efficacy of unlabelled small molecule antiangiogenic drugs in malignant tissue. Our approach is thus a major technical and preclinical advance demonstrating that primary resistance to angiogenesis inhibitors involves limited tumor tissue drug penetration. We also conclude that MALDI-MSI may significantly contribute to the improvement of antivascular cancer therapies.

Metronomic chemotherapy: A relook at its basis and rationale

Metronomic administration of chemotherapy has long been recognized as having a different biological effect from maximal tolerated dose (MTD) administration. Preclinical studies have demonstrated these differences quite elegantly and many clinical trials have also demonstrated reproducible activity albeit small, in varied solid malignancies even in patients who were heavily pretreated. However, the concept of metronomic chemotherapy has been plagued by lack of a clear definition resulting in the published literature that is rather varied and confusing. There is a need for a definition that is mechanism(s)-based allowing metronomics to be distinguished from standard MTD concept. With significant advances made in understanding cancer biology and biotechnology, it is now possible to attain that goal. What is needed is both a concerted effort and adequate funding to work towards it. This is the only way for the oncology community to determine how metronomic chemotherapy fits in the overall cancer management schema.

Angiogenic cytokines and their influence on circulating tumour cells in sera of patients with the primary diagnosis of breast cancer before treatment

Background

Circulating tumour cells (CTCs) have been found to be a prognostic marker for reduced disease free survival, breast cancer–specific survival, and overall survival before the start of systemic treatment.

Methods

A total of 200 patients’ sera were included in this study, 100 patients being CTC positive and 100 patients being CTC negative. Matching criteria were histo-pathological grading, lymph node metastasis, hormone receptor status, TNM classification and survived breast cancer patients vs. deceased tumor associated patients. A multi cytokine/chemokine array was used to screen the sera for the angiogenic markers.

Results

Statistical significant correlation was exposed for sFlt1 values in regard to the CTC-Status. CTC negative patients displayed increased sFlt1 expression opposed to CTC positive breast cancer patients. Furthermore, significant enhanced PIGF values were also disclosed in CTC negative patients compared to patients being CTC positive. Analyzing the living patient collective we found significant differences in sFlt1 and PlGF values in regard to CTC negative and CTC positive patients.

Conclusion

Both vascular markers showed enhanced expression in the CTC negative patient collective. To continue, the collective graded G2 showed significantly enhanced sFlt1 expressions amongst patients with no CTCs. Moreover, the patient collective with no lymph node metastasis and CTC negativity indicated statistically significant increased sFlt1 values. A functional interaction of sFlt1 and PlGF was found, suggesting that their overexpression in tumour cells inhibits CTCs entering the peripheral blood. Furthermore, in regard to CTC negativity, sFlt1 and PlGF values may potentially serve as predictive markers.

Trial registration

The TRN of this study is NCT02181101 and the date of registration was the 4^th of June 2014. The study was retrospectively registered.

Regorafenib for the Treatment of Advanced Gastric Cancer (INTEGRATE): A Multinational Placebo-Controlled Phase II Trial

PURPOSE

We evaluated the activity of regorafenib, an oral multikinase inhibitor, in advanced gastric adenocarcinoma.

PATIENTS AND METHODS

We conducted an international (Australia and New Zealand, South Korea, and Canada) randomized phase II trial in which patients were randomly assigned at a two-to-one ratio and stratified by lines of prior chemotherapy for advanced disease (one v two) and region. Eligible patients received best supportive care plus regorafenib 160 mg or matching placebo orally on days 1 to 21 of each 28-day cycle until disease progression or prohibitive adverse events occurred. The primary end point was progression-free survival (PFS). Final analysis included data to December 31, 2014.

RESULTS

A total of 152 patients were randomly assigned from November 7, 2012, to February 25, 2014, yielding 147 evaluable patients (regorafenib, n = 97; placebo, n = 50). Baseline characteristics were balanced. Median PFS significantly differed between groups (regorafenib, 2.6 months; 95% CI, 1.8 to 3.1 and placebo, 0.9 months; 95% CI, 0.9 to 0.9; hazard ratio [HR], 0.40; 95% CI, 0.28 to 0.59; P < .001). The effect was greater in South Korea than in Australia, New Zealand, and Canada combined (HR, 0.12 v 0.61; interaction P < .001) but consistent across age, neutrophil-to-lymphocyte ratio, primary site, lines of chemotherapy, peritoneal metastasis presence, number of metastatic sites, and plasma vascular endothelial growth factor A. A survival trend in favor of regorafenib was seen (median, 5.8 months; 95% CI, 4.4 to 6.8 v 4.5 months; 95% CI, 3.4 to 5.2; HR, 0.74; P = .147). Twenty-nine patients assigned to placebo received open-label regorafenib after disease progression. Regorafenib toxicity was similar to that previously reported.

CONCLUSION

In this phase II trial, regorafenib was effective in prolonging PFS in refractory advanced gastric adenocarcinoma. Regional differences were found, but regorafenib was effective in both regional groups. A phase III trial is planned.

Survivin Modulates Squamous Cell Carcinoma-Derived Stem-Like Cell Proliferation, Viability and Tumor Formation in Vivo

Squamous Cell Carcinoma-derived Stem-like Cells (SCC-SC) originate from alterations in keratinocyte stem cells (KSC) gene expression and sustain tumor development, invasion and recurrence. Since survivin, a KSC marker, is highly expressed in SCC-SC, we evaluate its role in SCC-SC cell growth and SCC models. Survivin silencing by siRNA decreases clonal growth of SCC keratinocytes and viability of total, rapidly adhering (RAD) and non-RAD (NRAD) cells from primary SCC. Similarly, survivin silencing reduces the expression of stem cell markers (OCT4, NOTCH1, CD133, β₁-integrin), while it increases the level of differentiation markers (K10, involucrin). Moreover, survivin silencing improves the malignant phenotype of SCC 3D-reconstruct, as demonstrated by reduced epidermal thickness, lower Ki-67 positive cell number, and decreased expression of MMP9 and psoriasin. Furthermore, survivin depletion by siRNA in Ras^G12V-IκBα-derived tumors leads to smaller tumor formation characterized by lower mitotic index and reduced expression of the tumor-associated marker HIF1α, VEGF and CD51. Therefore, our results indicate survivin as a key gene in regulating SCC cancer stem cell formation and cSCC development.

The Extraordinary Progress in Very Early Cancer Diagnosis and Personalized Therapy: The Role of Oncomarkers and Nanotechnology

The impact of nanotechnology on oncology is revolutionizing cancer diagnosis and therapy and largely improving prognosis. This is mainly due to clinical translation of the most recent findings in cancer research, that is, the application of bio- and nanotechnologies. Cancer genomics and early diagnostics are increasingly playing a key role in developing more precise targeted therapies for most human tumors. In the last decade, accumulation of basic knowledge has resulted in a tremendous breakthrough in this field. Nanooncology, through the discovery of new genetic and epigenetic biomarkers, has facilitated the development of more sensitive biosensors for early cancer detection and cutting-edge multifunctionalized nanoparticles for tumor imaging and targeting. In the near future, nanooncology is expected to enable a very early tumor diagnosis, combined with personalized therapeutic approaches.

Elevated Serum MicroRNA Let-7c in Moyamoya Disease

BACKGROUND

Few studies have examined the relationship between mircroRNAs and moyamoya disease (MMD). We performed a study of the significance of let-7c expression in the serum of MMD patients.

METHODS

The experimental group includes 49 MMD patients, and the control group consists of 30 normal people, 20 cerebral hemorrhage patients, 20 massive cerebral infarction patients, 20 nonmassive cerebral infarction patients, and 20 neurological autoimmune disease patients. Let-7 family levels were determined by polymerase chain reaction. A dual luciferase assay was used to test whether let-7c recognized the 3'UTR of RNF213.

RESULTS

The expression level of let-7c in MMD patients is higher than that observed in the control groups (P < .001). The luciferase assay results indicated that hsa-let-7c could diminish luciferase activity from a reporter vector containing the 3'-UTR of RNF213 (P < .05). The suppression of luciferase activity is not found in mutRNF213 (P > .05).

CONCLUSIONS

Increased expression of let-7c in MMD patients may contribute to MMD pathogenesis by targeting RNF213. Thus, let-7c may be a potential biomarker for the diagnosis of MMD.

An immature B cell population from peripheral blood serves as surrogate marker for monitoring tumor angiogenesis and anti-angiogenic therapy in mouse models

Tumor growth depends on the formation of new blood vessels (tumor angiogenesis) either from preexisting vessels or by the recruitment of bone marrow-derived cells. Despite encouraging results obtained with preclinical cancer models, the therapeutic targeting of tumor angiogenesis has thus far failed to deliver an enduring clinical response in cancer patients. One major obstacle for improving anti-angiogenic therapy is the lack of validated biomarkers, which allow patient stratification for suitable treatment and a rapid assessment of therapy response. Toward these goals, we have employed several mouse models of tumor angiogenesis to identify cell populations circulating in their blood that correlated with the extent of tumor angiogenesis and therapy response. Flow cytometry analyses of different combinations of cell surface markers that define subsets of bone marrow-derived cells were performed on peripheral blood mononuclear cells from tumor-bearing and healthy mice. We identified one cell population, CD45(dim)VEGFR1(-)CD31(low), that was increased in levels during active tumor angiogenesis in a variety of transgenic and syngeneic transplantation mouse models of cancer. Treatment with various anti-angiogenic drugs did not affect CD45(dim)VEGFR1(-)CD31(low) cells in healthy mice, whereas in tumor-bearing mice, a consistent reduction in their levels was observed. Gene expression profiling of CD45(dim)VEGFR1(-)CD31(low) cells characterized these cells as an immature B cell population. These immature B cells were then directly validated as surrogate marker for tumor angiogenesis and of pharmacologic responses to anti-angiogenic therapies in various mouse models of cancer.

Targeting Angiogenesis in Cancer Therapy: Moving Beyond Vascular Endothelial Growth Factor

Angiogenesis, or the formation of new capillary blood vessels, occurs primarily during human development and reproduction; however, aberrant regulation of angiogenesis is also a fundamental process found in several pathologic conditions, including cancer. As a process required for invasion and metastasis, tumor angiogenesis constitutes an important point of control of cancer progression. Although not yet completely understood, the complex process of tumor angiogenesis involves highly regulated orchestration of multiple signaling pathways. The proangiogenic signaling molecule vascular endothelial growth factor (VEGF) and its cognate receptor (VEGF receptor 2 [VEGFR-2]) play a central role in angiogenesis and often are highly expressed in human cancers, and initial clinical efforts to develop antiangiogenic treatments focused largely on inhibiting VEGF/VEGFR signaling. Such approaches, however, often lead to transient responses and further disease progression because angiogenesis is regulated by multiple pathways that are able to compensate for each other when single pathways are inhibited. The platelet-derived growth factor (PDGF) and PDGF receptor (PDGFR) and fibroblast growth factor (FGF) and FGF receptor (FGFR) pathways, for example, provide potential escape mechanisms from anti-VEGF/VEGFR therapy that could facilitate resumption of tumor growth. Accordingly, more recent treatments have focused on inhibiting multiple signaling pathways simultaneously. This comprehensive review discusses the limitations of inhibiting VEGF signaling alone as an antiangiogenic strategy, the importance of other angiogenic pathways including PDGF/PDGFR and FGF/FGFR, and the novel current and emerging agents that target multiple angiogenic pathways for the treatment of advanced solid tumors.

IMPLICATIONS FOR PRACTICE

Significant advances in cancer treatment have been achieved with the development of antiangiogenic agents, the majority of which have focused on inhibition of the vascular endothelial growth factor (VEGF) pathway. VEGF targeting alone, however, has not proven to be as efficacious as originally hoped, and it is increasingly clear that there are many interconnected and compensatory pathways that can overcome VEGF-targeted inhibition of angiogenesis. Maximizing the potential of antiangiogenic therapy is likely to require a broader therapeutic approach using a new generation of multitargeted antiangiogenic agents.

Comparison of the blood and lymphatic microvessel density of pleomorphic adenoma and Basal cell adenoma

BACKGROUND

Pleomorphic adenoma (PA) is the most common tumor of the salivary gland, while basal cell adenoma (BCA) is an uncommon neoplasm. Blood and lymphatic vessels are crucial for tumor metabolism. The aim of this study was to compare the blood and lymphatic vascular density and vascular and endothelial growth factor (VEGF) expression in PA and BCA tumors. In addition, cell proliferation was evaluated in these tumors.

METHODS

Blood and lymphatic vessel content, VEGF expression, and cell proliferation were analyzed in 30 cases of PA and 13 cases of BCA by immu-nohistochemistry using antibodies for CD34, CD105, D2–40, VEGF, and Mcm−2.

RESULTS

Regarding CD34 and CD105 expression, PA demonstrated a high vascularity and a low number of positive vessels, respectively. D2–40-positive lymphatic vessels were mainly located in the tumor capsules, with small intratumoral lymphatic vessels observed occasionally. VEGF expression revealed a remarkably heterogeneous immunoreactivity, alternating from weak or negative to positive or intense. BCA presented significantly higher CD34, CD34, CD105, D2–40, and VEGF expression compared to PA. No significant difference was found in cell proliferation between the tumors.

CONCLUSION

Although PA and BCA are considered part of the same spectrum of differentiation, this study showed that the blood and lymphatic vascularization of these tumors is different.

Anti-vascular endothelial growth factor therapy in breast cancer

Neo-angiogenesis is a critical process for tumor growth and invasion and has become a promising target in cancer therapy. This manuscript reviews three currently relevant anti-angiogenic agents targeting the vascular endothelial growth factor system: bevacizumab, ramucirumab and sorafenib. The efficacy of anti-angiogenic drugs in adjuvant therapy or as neo-adjuvant treatment has been estimated in clinical trials of advanced breast cancer. To date, the overall observed clinical improvements are unconvincing, and further research is required to demonstrate the efficacy of anti-angiogenic drugs in breast cancer treatments. The outcomes of anti-angiogenic therapy have been highly variable in terms of tumor response. New methods are needed to identify patients who will benefit from this regimen. The development of biomarkers and molecular profiling are relevant research areas that may strengthen the ability to focus anti-angiogenic therapy towards suitable patients, thereby increase the cost-effectiveness, currently estimated to be inadequate.

Circulating endothelial cells as a biomarker in non-small cell lung cancer patients: correlation with clinical outcome

BACKGROUND

Circulating endothelial cells (CECs) have been proposed as a biomarker for the assessment of patients with solid tumors. However, few data are available in non-small cell lung cancer (NSCLC). We therefore analyzed the clinical significance of CECs in newly diagnosed NSCLC patients. In addition, we tried to determine the prognostic value of CECs in NSCLC.

METHODS

In this prospective study, 151 newly diagnosed NSCLC patients and 25 healthy volunteers were included. Furthermore, 25 patients with a partial response (n=15) or stable disease (n=10) after treatment were evaluated at recurrence with a mean follow-up of 117 days (range: 47-364 days). CECs were counted using magnetic beads coupled to a specific antibody against CD146.

RESULTS

The pre-treatment CEC count was significantly higher in patients with all histological subtypes of NSCLC than in healthy volunteers (p&lt;0.0001). High baseline CEC counts were significantly correlated with advanced clinical stages (p=0.026), weight loss (p=0.03), and poorly differentiated NSCLC (p=0.02). The amount of CECs increased significantly at recurrence compared with their amount after treatment in 20/21 assessable patients (p=0.0001). Nevertheless, there was no significant correlation between baseline CEC count and median duration of progression-free survival (p=0.402).

CONCLUSIONS

Increased CEC counts were present in patients with newly diagnosed NSCLC compared with healthy subjects. Elevated levels of baseline CECs correlated with high-risk factors in NSCLC. In addition, increased CEC count during follow-up seems to be correlated with recurrence in NSCLC patients.

Screening of antiangiogenic potential of twenty two marine invertebrate extracts of phylum Mollusca from South East Coast of India

OBJECTIVE

To evaluate the antiangiogenic potential of twenty two marine invertebrate species of Phylum Mollusca from south east coast of India.

METHODS

Live specimens of molluscan species were collected and their methanolic extracts were evaluated for preliminary antiangiogenic activity using the in ovo chick chorio-allantoic membrane assay. The extracts were further evaluated for in vivo antiangiogenic activity using chemical cautery induced corneal neovascularization assay in rats and oxygen induced retinopathy assay in rat pups.

RESULTS

In the chick chorio-allantoic membrane assay, four methanolic extracts of marine molluscan species viz. Meretrix meretrix, Meretrix casta, Telescopium telescopium and Bursa crumena methanolic extracts exhibited noticeable antiangiogenic activity at the tested concentration of 200 µg whereby they significantly inhibited the VEGF induced proliferation of new blood vessels. Among these four extracts, the methanolic extract of Meretrix casta exhibited relatively higher degree of antiangiogenic activity with an inhibitiory percentage (64.63%) of the VEGF induced neovascularization followed by the methanolic extracts of Telescopium telescopium (62.02%), Bursa crumena (60.48%) and Meretrix meretrix (47.01%). These four methanolic extracts were further evaluated for in vivo antiangiogenic activity whereby the methanolic extract of Telescopium telescopium exhibited most noticeable inhibition (42.58%) of the corneal neovascularization in rats in comparison to the sham treated group, and also exhibited most noticeable inhibition (31.31%) of the oxygen induced retinal neovascularization in rat pups in comparison to the hyperoxia group that was observed for considerable retinal neovascularization.

CONCLUSIONS

The significant antiangiogenic activity evinced by the extract of Telescopium telescopium merits further investigation for ocular neovascular diseases.

Bidirectional regulation of angiogenesis and miR-18a expression by PNS in the mouse model of tumor complicated by myocardial ischemia

Background

Panax Notoginseng Saponins (PNS) is the major class of active constituents of notoginseng, a natural product extensively used as a therapeutic agent in China. Tumor when accompanied by cardiovascular disorders poses a greater challenge for clinical management given the paradoxical involvement of angiogenesis, therefore gaining increased research attention. This study aim to investigate effects of PNS and its activity components in the mouse model of tumor complicated with myocardial ischemia.

Methods

Tumor complexed with myocardial ischemia mouse model was first established, which was followed by histological and immunohistochemistry examination to assess the effect of indicated treatments on tumor, myocardial ischemia and tissue specific angiogenesis. MicroRNA (miRNA) profiling was further carried out to identify potential miRNA regulators that might mechanistically underline the therapeutic effects of PNS in this complex model.

Results

PNS and its major activity components Rg1, Rb1 and R1 suppressed tumor growth and simultaneously attenuated myocardial ischemia. PNS treatment led to decreased expression of CD34 and vWF in tumor and increased expression of these vascular markers in heart. PNS treatment resulted in reduced expression of miR-18a in tumor and upregulated expression of miR-18a in heart.

Conclusions

Our data demonstrated for the first time that PNS exerts tissue specific regulatory effects on angiogenesis in part through modulating the expression of miR-18a, which could be responsible for its bidirectional effect on complex disease conditions where paradoxical angiogenesis is implicated. Therefore, our study provides experimental evidence warranting evaluation of PNS and related bioactive component as a rational therapy for complex disease conditions including co-manifestation of cancer and ischemic cardiovascular disease.

Critical role of aberrant angiogenesis in the development of tumor hypoxia and associated radioresistance

Newly formed microvessels in most solid tumors show an abnormal morphology and thus do not fulfil the metabolic demands of the growing tumor mass. Due to the chaotic and heterogeneous tumor microcirculation, a hostile tumor microenvironment develops, that is characterized inter alia by local hypoxia, which in turn can stimulate the HIF-system. The latter can lead to tumor progression and may be involved in hypoxia-mediated radioresistance of tumor cells. Herein, cellular and molecular mechanisms in tumor angiogenesis are discussed that, among others, might impact hypoxia-related radioresistance.

Immunohistochemical levels of cyclo-oxygenase-2, matrix metalloproteinase-9 and vascular endothelial growth factor in papillary thyroid carcinoma and their clinicopathological correlations

OBJECTIVE

To measure the levels of cyclo-oxygenase (COX)-2, matrix metalloproteinase (MMP)-9 and vascular endothelial growth factor (VEGF) immunostaining in papillary thyroid carcinoma (PTC) and benign thyroid tumours, and to investigate potential correlations between their levels and clinicopathological characteristics.

METHODS

The levels of immunohistochemical staining of COX-2, MMP-9 and VEGF proteins were measured in tumours from patients with PTC and compared with specimens from patients with benign thyroid tumours. The association between the levels of COX-2, MMP-9 and VEGF proteins and clinicopathological characteristics in patients with PTC was also analysed.

RESULTS

A total of 66 patients with PTC and 40 patients with benign thyroid tumours participated in the study. The rates of positive immunostaining for COX-2, MMP-9 and VEGF in PTC tumours were significantly higher than those in benign thyroid tumours. There were significant positive associations between positive immunostaining for COX-2, MMP-9 and VEGF proteins and age (≥45 years), clinical stage (III-IV) and tumour diameter (≥ 2 cm).

CONCLUSION

Combined immunohistochemical evaluation of the levels of COX-2, MMP-9 and VEGF in PTC might be a useful marker for the diagnosis of PTC.

Compartment model predicts VEGF secretion and investigates the effects of VEGF trap in tumor-bearing mice

Angiogenesis, the formation of new blood vessels from existing vasculature, is important in tumor growth and metastasis. A key regulator of angiogenesis is vascular endothelial growth factor (VEGF), which has been targeted in numerous anti-angiogenic therapies aimed at inhibiting tumor angiogenesis. Systems biology approaches, including computational modeling, are useful for understanding this complex biological process and can aid in the development of novel and effective therapeutics that target the VEGF family of proteins and receptors. We have developed a computational model of VEGF transport and kinetics in the tumor-bearing mouse, which includes three-compartments: normal tissue, blood, and tumor. The model simulates human tumor xenografts and includes human (VEGF121 and VEGF165) and mouse (VEGF120 and VEGF164) isoforms. The model incorporates molecular interactions between these VEGF isoforms and receptors (VEGFR1 and VEGFR2), as well as co-receptors (NRP1 and NRP2). We also include important soluble factors: soluble VEGFR1 (sFlt-1) and α-2-macroglobulin. The model accounts for transport via macromolecular transendothelial permeability, lymphatic flow, and plasma clearance. We have fit the model to available in vivo experimental data on the plasma concentration of free VEGF Trap and VEGF Trap bound to mouse and human VEGF in order to estimate the rates at which parenchymal cells (myocytes and tumor cells) and endothelial cells secrete VEGF. Interestingly, the predicted tumor VEGF secretion rates are significantly lower (0.007-0.023 molecules/cell/s, depending on the tumor microenvironment) than most reported in vitro measurements (0.03-2.65 molecules/cell/s). The optimized model is used to investigate the interstitial and plasma VEGF concentrations and the effect of the VEGF-neutralizing agent, VEGF Trap (aflibercept). This work complements experimental studies performed in mice and provides a framework with which to examine the effects of anti-VEGF agents, aiding in the optimization of such anti-angiogenic therapeutics as well as analysis of clinical data. The model predictions also have implications for biomarker discovery with anti-angiogenic therapies.