Angiogenesis in prostate cancer: its role in disease progression and possible therapeutic approaches

The Pros and Cons of Estrogens in Prostate Cancer: An Update with a Focus on Phytoestrogens

The role of estrogens in prostate cancer (PCa) is shrouded in mystery, with its actions going from angelic to devilish. The findings by Huggins and Hodges establishing PCa as a hormone-sensitive cancer have provided the basis for using estrogens in therapy. However, despite the clinical efficacy in suppressing tumor growth and the panoply of experimental evidence describing its anticarcinogenic effects, estrogens were abolished from PCa treatment because of the adverse secondary effects. Notwithstanding, research work over the years has continued investigating the effects of estrogens, reporting their pros and cons in prostate carcinogenesis. In contrast with the beneficial therapeutic effects, many reports have implicated estrogens in the disruption of prostate cell fate and tissue homeostasis. On the other hand, epidemiological data demonstrating the lower incidence of PCa in Eastern countries associated with a higher consumption of phytoestrogens support the beneficial role of estrogens in counteracting cancer development. Many studies have investigated the effects of phytoestrogens and the underlying mechanisms of action, which may contribute to developing safe estrogen-based anti-PCa therapies. This review compiles the existing data on the anti- and protumorigenic actions of estrogens and summarizes the anticancer effects of several phytoestrogens, highlighting their promising features in PCa treatment.

Differential tempol effects in prostatic cancer: angiogenesis and short- and long-term treatments

Prostate cancer (PCa) is the second cause of cancer death among men worldwide. Several processes are involved in the development and progression of PCa such as angiogenesis, inflammation and oxidative stress. The present study investigated the effect of short- or long-term Tempol treatment at different stages of prostate adenocarcinoma progression, focusing on angiogenic, proliferative, and stromal remodeling processes in TRAMP mice. The dorsolateral lobe of the prostate of TRAMP mice were evaluated at two different stages of PCa progression; early and late stages. Early stage was again divided into, short- or long-term. 50 mg/kg Tempol dose was administered orally. The results demonstrated that Tempol mitigated the prostate histopathological lesion progressions in the TRAMP mice in all treated groups. However, Tempol increased molecules involved in the angiogenic process such as CD31 and VEGFR2 relative frequencies, particularly in long-term treatment. In addition, Tempol upregulated molecule levels involved in angiogenesis and stromal remodeling process VEGF, TGF-β1, VE-cadherin and vimentin, particularly, in T8-16 group. Thus, it was concluded that Tempol treatment delayed prostatic lesion progression in the dorsolateral lobe of the TRAMP mice. However, Tempol also led to pro-angiogenic effects and glandular stromal microenvironment imbalance, especially, in the long-term treatment.

Deep learning-based automated pipeline for blood vessel detection and distribution analysis in multiplexed prostate cancer images

Introduction: Prostate cancer is a highly heterogeneous disease, presenting varying levels of aggressiveness and response to treatment. Angiogenesis is one of the hallmarks of cancer, providing oxygen and nutrient supply to tumors. Micro vessel density has previously been correlated with higher Gleason score and poor prognosis. Manual segmentation of blood vessels (BVs) In microscopy images is challenging, time consuming and may be prone to inter-rater variabilities. In this study, an automated pipeline is presented for BV detection and distribution analysis in multiplexed prostate cancer images. Methods: A deep learning model was trained to segment BVs by combining CD31, CD34 and collagen IV images. In addition, the trained model was used to analyze the size and distribution patterns of BVs in relation to disease progression in a cohort of prostate cancer patients (N = 215). Results: The model was capable of accurately detecting and segmenting BVs, as compared to ground truth annotations provided by two reviewers. The precision (P), recall (R) and dice similarity coefficient (DSC) were equal to 0.93 (SD 0.04), 0.97 (SD 0.02) and 0.71 (SD 0.07) with respect to reviewer 1, and 0.95 (SD 0.05), 0.94 (SD 0.07) and 0.70 (SD 0.08) with respect to reviewer 2, respectively. BV count was significantly associated with 5-year recurrence (adjusted p = 0.0042), while both count and area of blood vessel were significantly associated with Gleason grade (adjusted p = 0.032 and 0.003 respectively). Discussion: The proposed methodology is anticipated to streamline and standardize BV analysis, offering additional insights into the biology of prostate cancer, with broad applicability to other cancers.

Integrative Analysis of Bulk RNA-Seq and Single-Cell RNA-Seq Unveils the Characteristics of the Immune Microenvironment and Prognosis Signature in Prostate Cancer

The immune microenvironment is a culmination of the collaborative effort of immune cells and is important in cancer development. The underlying mechanisms of the tumor immune microenvironment in regulating prostate cancer (PRAD) are unclear. In the current study, 144 natural killer cell-related genes were identified using differential expression, single-sample gene set enrichment analysis, and weighted gene coexpression network analysis. Furthermore, VCL, ACTA2, MYL9, MYLK, MYH11, TPM1, ACTG2, TAGLN, and FLNC were selected as hub genes via the protein-protein interaction network. Based on the expression patterns of the hub genes, endothelial, epithelial, and tissue stem cells were identified as key cell subpopulations, which could regulate PRAD via immune response, extracellular signaling, and protein formation. Moreover, 27 genes were identified as prognostic signatures and used to construct the risk score model. Receiver operating characteristic curves revealed the good performance of the risk score model in both the training and testing datasets. Different chemotherapeutic responses were observed between the low- and high-risk groups. Additionally, a nomogram based on the risk score and other clinical features was established to predict the 1-, 3-, and 5-year progression-free interval of patients with PRAD. This study provides novel insights into the molecular mechanisms of the immune microenvironment and its role in the pathogenesis of PARD. The identification of key cell subpopulations has a potential therapeutic and prognostic use in PRAD.

Use of conditional reprogramming cell, patient derived xenograft and organoid for drug screening for individualized prostate cancer therapy: Current and future perspectives (Review)

Prostate cancer mortality is ranked second among all cancer mortalities in men worldwide. There is a great need for a method of efficient drug screening for precision therapy, especially for patients with existing drug‑resistant prostate cancer. Based on the concept of bacterial cell culture and drug sensitivity testing, the traditional approach of cancer drug screening is inadequate. The current and more innovative use of cancer cell culture and in vivo tumor models in drug screening for potential individualization of anti‑cancer therapy is reviewed and discussed in the present review. An ideal screening model would have the ability to identify drug activity for the targeted cells resembling what would have occurred in the in vivo environment. Based on this principle, three available cell culture/tumor screening models for prostate cancer are reviewed and considered. The culture conditions, advantages and disadvantages for each model together with ideas to best utilize these models are discussed. The first screening model uses conditional reprogramed cells derived from patient cancer cells. Although these cells are convenient to grow and use, they are likely to have different markers and characteristics from original tumor cells and thus not likely to be informative. The second model employs patient derived xenograft (PDX) which resembles an in vivo approach, but its main disadvantages are that it cannot be easily genetically modified and it is not suitable for high‑throughput drug screening. Finally, high‑throughput screening is more feasible with tumor organoids grown from patient cancer cells. The last system still needs a large number of tumor cells. It lacks in situ blood vessels, immune cells and the extracellular matrix. Based on these current models, future establishment of an organoid data bank would allow the selection of a specific organoid resembling that of an individual's prostate cancer and used for screening of suitable anticancer drugs. This can be further confirmed using the PDX model. Thus, this combined organoid‑PDX approach is expected to be able to provide the drug sensitivity testing approach for individualization of prostate cancer therapy in the near future.

Dynamic contrast-enhanced magnetic resonance imaging for risk stratification in patients with prostate cancer

BACKGROUND

To investigate the usefulness of perfusion parameters derived from dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) of patients diagnosed as prostate cancer (PCa) in differentiating clinically significant cancer [CSC, Gleason score (GS) ≥7] from non-CSC (GS 6).

METHODS

A total of 94 patients diagnosed between August 2018 and September 2020 as PCa by radical prostatectomy were included in this retrospective study (mean age: 68.7 years, range, 47-83 years). All of the patients had undergone DCE-MRI on a single 3T-MR scanner. Whole-tumor volume was measured by reviewing a pathologic topographic map as a reference standard. The quantitative DCE perfusion parameters, including volume transfer constant (K^trans), rate constant (k_ep), extracellular extravascular space (EES) volume fraction (v_e), plasma volume fraction (v_p) and area of region of interest (ROI) were calculated under an extended Tofts model. A receiver operating characteristic (ROC) curve analysis by pair-wise comparison was performed to compare the diagnostic performances of the perfusion parameters.

RESULTS

The study population comprised GS 6 (n=17), GS 7 (n=57), GS 8 (n=9) and GS 9 (n=11) cases. Among the perfusion parameters, v_e differed significantly between CSC (0.238±0.095) and non-CSC (0.300±0.126) (P=0.0308). Area under the curve (AUC) was 0.643 (95% CI, 0.538-0.739), and a maximum accuracy of 64%, a sensitivity of 66%, and a specificity of 53% were estimated. Area of ROI also differed significantly between CSC (201.89±163.87 mm²) and non-CSC (84.99±85.82 mm²) (P=0.0054). AUC was 0.807 (95% CI, 0.713-0.881), and maximum accuracy, sensitivity, and specificity were 81%, 82%, and 76%, respectively.

CONCLUSIONS

Size of the tumor and interstitial space volume fraction are significant parameters in differentiating aggressiveness in PCa.

Vasohibin-1 expression as a biomarker of aggressive nature in ductal adenocarcinoma of the prostate: a retrospective cohort study at two centres in Japan

OBJECTIVES

Vasohibin-1 (VASH1) is an endogenous angiogenesis regulator expressed in activated vascular endothelial cells. We previously reported that high VASH1 expression is a predictor of progression in acinar adenocarcinoma of the prostate. In this study, we evaluated the characteristics of ductal adenocarcinoma of the prostate by comparing the level of VASH1 expression between ductal and acinar adenocarcinoma specimens.

DESIGN AND SETTING

A retrospective cohort study at two centres in Japan.

PARTICIPANTS

Among the 1495 patients who underwent radical prostatectomy or transurethral resection for the past 15 years, a total of 14 patients diagnosed with ductal adenocarcinoma and 20 patients diagnosed with acinar adenocarcinoma with a Gleason score of 4+4 were included.

INTERVENTIONS

We immunohistochemically examined the CD34 expression as the microvessel density (MVD) and activated endothelial cells as the VASH1 density (vessels per mm²).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the association of MVD and VASH1 density between ductal and acinar adenocarcinoma, and the secondary outcome was their oncological outcomes.

RESULTS

Nine patients (64.3%) with ductal adenocarcinoma were diagnosed at an advanced clinical stage, and five patients (35.7%) died from cancer during a median follow-up of 56.0 months. The VASH1 densities (mean±SD) in ductal and acinar adenocarcinoma were 45.1±18.5 vs 16.1±21.0 (p<0.001), respectively, while the MVD (mean±SD) in ductal and acinar adenocarcinoma were 65.3±21.9 vs 80.8±60.7 (p=0.666), respectively. The 5-year cancer-specific survival rates for high and low VASH1 expression were 70.0% and 100.0% (p=0.006), respectively. High VASH1 expression and a diagnosis of ductal adenocarcinoma were significant predictors of cancer-specific survival.

CONCLUSIONS

Ductal adenocarcinoma was more aggressive and had higher VASH1 expression than acinar adenocarcinoma, although MVD was equivalent. These results indicate that VASH1 expression may serve as a novel biomarker for the aggressive nature of ductal adenocarcinoma.

Quantitative colour Doppler and greyscale ultrasound for evaluating prostate cancer

Introduction

Although transrectal ultrasound is routinely performed for imaging prostate lesions, colour Doppler imaging visualizing vascularity is not commonly used for diagnosis. The goal of this study was to measure vascular and echogenic differences between malignant and benign lesions of the prostate by quantitative colour Doppler and greyscale transrectal ultrasound.

Methods

Greyscale and colour Doppler ultrasound images of the prostate were acquired in 16 subjects with biopsy-proven malignant or benign lesions. Echogenicity and microvascular flow velocity of each lesion were measured by quantitative image analysis. Flow velocity was measured over several cardiac cycles and the velocity-time waveform was used to determine microvascular pulsatility index and microvascular resistivity index. The Wilcoxon rank sum test was used to compare the malignant and benign groups.

Results

Median microvascular flow velocity of the malignant lesions was 1.25 cm/s compared to 0.36 cm/s for the benign lesions. Median pulsatility and resistive indices of the malignant lesions were 1.55 and 0.68, respectively versus 6.38 and 1.0 for the benign lesions. Malignant lesions were more hypoechoic relative to the surrounding tissue, with median echogenicity of 0.24 compared to 0.76 for the benign lesions. The differences between the malignant and benign groups for each measurement were significant (p < 0.01).

Conclusion

Marked differences were observed in flow velocity, microvascular pulsatility, microvascular resistance, and echogenicity of prostate cancer measured with quantitative colour Doppler and greyscale ultrasound imaging. Vascular differences measured together with echogenicity have the combined potential to characterize malignant and benign prostate lesions.

Tumor Microenvironment in Prostate Cancer: Toward Identification of Novel Molecular Biomarkers for Diagnosis, Prognosis, and Therapy Development

Prostate cancer (PCa) is by far the most commonly diagnosed cancer in men worldwide. Despite sensitivity to androgen deprivation, patients with advanced disease eventually develop resistance to therapy and may die of metastatic castration-resistant prostate cancer (mCRPC). A key challenge in the management of PCa is the clinical heterogeneity that is hard to predict using existing biomarkers. Defining molecular biomarkers for PCa that can reliably aid in diagnosis and distinguishing patients who require aggressive therapy from those who should avoid overtreatment is a significant unmet need. Mechanisms underlying the development of PCa are not confined to cancer epithelial cells, but also involve the tumor microenvironment. The crosstalk between epithelial cells and stroma in PCa has been shown to play an integral role in disease progression and metastasis. A number of key markers of reactive stroma has been identified including stem/progenitor cell markers, stromal-derived mediators of inflammation, regulators of angiogenesis, connective tissue growth factors, wingless homologs (Wnts), and integrins. Here, we provide a synopsis of the stromal-epithelial crosstalk in PCa focusing on the relevant molecular biomarkers pertaining to the tumor microenvironment and their role in diagnosis, prognosis, and therapy development.

Oncolytic Virus Encoding a Master Pro-Inflammatory Cytokine Interleukin 12 in Cancer Immunotherapy

Oncolytic viruses (OVs) are genetically modified or naturally occurring viruses, which preferentially replicate in and kill cancer cells while sparing healthy cells, and induce anti-tumor immunity. OV-induced tumor immunity can be enhanced through viral expression of anti-tumor cytokines such as interleukin 12 (IL-12). IL-12 is a potent anti-cancer agent that promotes T-helper 1 (Th1) differentiation, facilitates T-cell-mediated killing of cancer cells, and inhibits tumor angiogenesis. Despite success in preclinical models, systemic IL-12 therapy is associated with significant toxicity in humans. Therefore, to utilize the therapeutic potential of IL-12 in OV-based cancer therapy, 25 different IL-12 expressing OVs (OV-IL12s) have been genetically engineered for local IL-12 production and tested preclinically in various cancer models. Among OV-IL12s, oncolytic herpes simplex virus encoding IL-12 (OHSV-IL12) is the furthest along in the clinic. IL-12 expression locally in the tumors avoids systemic toxicity while inducing an efficient anti-tumor immunity and synergizes with anti-angiogenic drugs or immunomodulators without compromising safety. Despite the rapidly rising interest, there are no current reviews on OV-IL12s that exploit their potential efficacy and safety to translate into human subjects. In this article, we will discuss safety, tumor-specificity, and anti-tumor immune/anti-angiogenic effects of OHSV-IL12 as mono- and combination-therapies. In addition to OHSV-IL12 viruses, we will also review other IL-12-expressing OVs and their application in cancer therapy.

Molecular Links Between Angiogenesis and Neuroendocrine Phenotypes in Prostate Cancer Progression

As a common therapy for prostate cancer, androgen deprivation therapy (ADT) is effective for the majority of patients. However, prolonged ADT promotes drug resistance and progression to an aggressive variant with reduced androgen receptor signaling, so called neuroendocrine prostate cancer (NEPC). Until present, NEPC is still poorly understood, and lethal with no effective treatments. Elevated expression of neuroendocrine related markers and increased angiogenesis are two prominent phenotypes of NEPC, and both of them are positively associated with cancers progression. However, direct molecular links between the two phenotypes in NEPC and their mechanisms remain largely unclear. Their elucidation should substantially expand our knowledge in NEPC. This knowledge, in turn, would facilitate the development of effective NEPC treatments. We recently showed that a single critical pathway regulates both ADT-enhanced angiogenesis and elevated expression of neuroendocrine markers. This pathway consists of CREB1, EZH2, and TSP1. Here, we seek new insights to identify molecules common to pathways promoting angiogenesis and neuroendocrine phenotypes in prostate cancer. To this end, our focus is to summarize the literature on proteins reported to regulate both neuroendocrine marker expression and angiogenesis as potential molecular links. These proteins, often described in separate biological contexts or diseases, include AURKA and AURKB, CHGA, CREB1, EZH2, FOXA2, GRK3, HIF1, IL-6, MYCN, ONECUT2, p53, RET, and RB1. We also present the current efforts in prostate cancer or other diseases to target some of these proteins, which warrants testing for NEPC, given the urgent unmet need in treating this aggressive variant of prostate cancer.

Association of anti-inflammatory and antiangiogenic therapies negatively influences prostate cancer progression in TRAMP mice

BACKGROUND

Chronic inflammation has been implicated in cancer etiology and angiogenesis is stimulated in this disease. In prostate, the crosstalk between malignant epithelial cells and their microenvironment is an essential step of tumorigenesis during which glandular stroma undergo changes designated as reactive stroma. Thus, the aim herewith was to evaluate the effects of associating anti-inflammatory and antiangiogenic therapies on cancer progression, correlating them with steroid hormone receptor (AR and ERα), reactive stroma (vimentin, αSMA, and TGF-β), and cell proliferation (PCNA) markers expression in the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model.

METHODS

TRAMP mice (12-week old) were divided into the groups: Control (TRCON): received the vehicles used for drug dilution; Celecoxib (TRCEL): received oral doses of the anti-inflammatory drug celecoxib (15 mg/kg) twice daily; Nintedanib (TRNTB): received oral doses of the antiangiogenic drug nintedanib (10 mg/kg) daily; Nintedanib+Celecoxib (TRNTCEL): received the combination of drugs. After 6 weeks, mice were euthanized and ventral prostate samples were harvested for morphological, immunohistochemical, and Western blotting analyses.

RESULTS

While celecoxib led to fibromuscular hypertrophy attenuation, nintedanib significantly reduced the incidence of well-differentiated adenocarcinoma (WDAC) foci in relation to controls, both when administered per se or in association to celecoxib. Furthermore, drug combination was associated with unique effects, including lower incidence of HGPIN lesions; lower AR stromal distribution; changes in ERα localization from epithelial nuclei to stroma as well as significant decrease of TGF-β levels and associated angiogenesis. In parallel, all treatments applied resulted in reduced inflammatory marker and vimentin (VIM) expression.

CONCLUSIONS

Celecoxib plus nintedanib is an effective antitumor combination against prostate cancer progression in TRAMP mice, showing remarkable efficacy in relation to isolated therapies. Importantly, this efficacy might be due to drug association effect on driving AR and mainly ERα distribution in the prostatic tissue towards benign patterns. In addition, celecoxib and nintedanib impaired the development of a stromal reaction by reducing the recruitment of reactive stroma cells and maintaining a normal smooth muscle cell-rich prostate stroma in TRAMP mice. Collectively, these findings pointed to the beneficial effects of combining anti-inflammatory and antiangiogenic strategies to prevent or delay prostatic tumorigenesis.

Neuropeptide-induced modulation of carcinogenesis in a metastatic breast cancer cell line (MDA-MB-231LUC+)

Background

Metastatic cancer to bone is well-known to produce extreme pain. It has been suggested that the magnitude of this perceived pain is associated with disease progression and poor prognosis. These data suggest a potential cross-talk between cancer cells and nociceptors that contribute not only to pain, but also to cancer aggressiveness although the underlying mechanisms are yet to be stablished.

Methods

The in vitro dose dependent effect of neuropeptides (NPs) (substance P [SP], calcitonin gene-related peptide and neurokinin A [NKA]) and/or its combination, on the migration and invasion of MDA-MB-231^LUC+ were assessed by wound healing and collagen-based cell invasion assays, respectively. The effect of NPs on the expression of its receptors (SP [NK1] and neurokinin A receptors [NK2], CALCRL and RAMP1) and kininogen (high-molecular-weight kininogen) release to the cell culture supernatant of MDA-MB-231^LUC+, were measured using western-blot analysis and an ELISA assay, respectively. Statistical significance was tested using one-way ANOVA, repeated measures ANOVA, or the paired t-test. Post-hoc testing was performed with correction for multiple comparisons as appropriate.

Results

Our data show that NPs strongly modify the chemokinetic capabilities of a cellular line commonly used as a model of metastatic cancer to bone (MDA-MB-231^LUC+) and increased the expression of their receptors (NK1R, NK2R, RAMP1, and CALCRL) on these cells. Finally, we demonstrate that NPs also trigger the acute release of HMWK (Bradykinin precursor) by MDA-MB-231^LUC+, a molecule with both tumorigenic and pro-nociceptive activity.

Conclusions

Based on these observations we conclude that NPs exposure modulates this breast cancer cellular line aggressiveness by increasing its ability to migrate and invade new tissues. Furthermore, these results also support the pro nociceptive and cancer promoter role of the peripheral nervous system, during the initial stages of the disease.

The Value of Contrast-Enhanced Ultrasonography Combined with Real-Time Strain Elastography in the Early Diagnosis of Prostate Cancer

To evaluate the performance of a combination of real-time strain elastography (RTSE) and contrast-enhanced transrectal ultrasound (CETRUS) for prostate cancer detection. Patients with serum prostate-specific antigen (PSA) levels of ≥4.0 ng/ml were prospectively enrolled between June 2014 and December 2016. 153 prostate nodules diagnosed by conventional ultrasound were prospectively enrolled and examined by CETRUS and RTSE before a biopsy. Multivariate logistic regression models were established for CETRUS, and CETRUS combined with RTSE to diagnose prostate malignancy. The diagnostic performances of CETRUS, RTSE, and their combined use were evaluated with the receiver operating characteristic (ROC) curve. The multivariate logistic regression for CETRUS combined with RTSE showed that enhanced strength, enhanced uniformity, and elasticity scores were the independent predictors of prostate malignancy. The area under the ROC curve of CETRUS combined with RTSE (0.921±0.023) was higher than that of CETRUS and RTSE (0.88±0.029 and 0.80±0.038, respectively; both p<0.05). Moreover, the sensitivity, accuracy and negative predictive value of CETRUS combined with RTSE were 92.1%, 86.2%, and 84.6%, respectively. The omission diagnostic rate of CETRUS combined with RTSE (7.9%) was reduced. And the diagnostic accuracy of CETRUS combined with RTSE was significantly higher than that of CETRUS and RTSE (p<0.05). While the diagnostic accuracy of CETRUS was close to the RTSE, the difference was not statistically significant (p>0.05). The combined RTSE with CETRUS approach significantly improved the sensitivity and overall accuracy for correctly identifying prostate cancer.

Engulfment of platelets delays endothelial cell aging via girdin and its phosphorylation

Endothelial cells are critical in angiogenesis and maintain the homeostasis of the blood‑brain barrier (BBB). Platelets (PLTs) are essential in vascular biology, including angiogenesis. The present study aimed to investigate the effect of PLTs on the aging of endothelial cells. Human brain microvascular endothelial cells (HBMECs) and human astrocytes were co‑cultured to mimic the BBB. Transmission electron microscopy was used to observe the engulfment of PLTs. Confocal microscopy was used to observe the co‑localization of PLTs, girders of actin filament (girdin) and phosphorylated (p‑)girdin. Senescence‑associated β‑galactosidase (β‑gal) staining, 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide and flow cytometry were performed to examine the cell senescence, viability and apoptosis, respectively. Transwell assays were performed to examine cell invasion and migration. Western blot analysis was performed to detect the expression of girdin, AKT and p‑AKT. PLTs delayed senescence, and promoted the viability and resistance to apoptosis of the HBMECs. Cell invasion and migration were enhanced by PLTs. In addition, girdin and p‑girdin were essential to the engulfment of HBMECs to PLTs. Mechanically, the inhibition of AKT signals reversed the effect of PLTs on HBMECs by increasing the activity of β‑gal, decreasing the cell viability, and inhibiting the invasion and migration of the HBMECs. The engulfment of PLTs assisted in delaying the aging of endothelial cells via girdin and p‑girdin, in which the AKT signal was involved. The present study indicated a potential strategy for delaying endothelial cell aging in the treatment of central nervous system diseases.

Antiangiogenic effects of AA-PMe on HUVECs in vitro and zebrafish in vivo

Angiogenesis plays a vital role in many physiological and pathological processes and several diseases are connected with its dysregulation. Asiatic acid (AA) has demonstrated anticancer properties and we suspect this might be attributable to an effect on angio-genesis. A modified derivative of AA, N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-L-proline methyl ester (AA-PMe), has improved efficacy over its parent compound, but its effect on blood vessel development remains unclear.

Methods

In this study, we investigated the antiangiogenic activity of AA and AA-PMe in zebrafish embryos and human umbilical vein endothelial cells (HUVECs). First of all, we treated HUVECs with increasing concentrations of AA-PMe or AA, with or without vascular endothelial growth factor (VEGF) present, and assessed cell viability, tube formation, and cell migration and invasion. Quantitative real-time polymerase chain reaction and Western blot analysis were later used to determine the role of vascular endothelial growth factor receptor 2 (VEGFR2)-mediated signaling in AA-PMe inhibition of angiogenesis. We extended these studies to follow angiogenesis using Tg(fli:EGFP) transgenic zebrafish embryos. For these experiments, embryos were treated with varying concentrations of AA-PMe or AA from 24 to 72 hours postfertilization prior to morphological observation, angiogenesis assessment, and endogenous alkaline phosphatase assay. VEGFR2 expression in whole embryos following AA-PMe treatment was also determined.

Results

We found AA-PMe decreased cell viability and inhibited migration and tube formation in a dose-dependent manner in HUVECs. Similarly, AA-PMe disrupted the formation of intersegmental vessels, the dorsal aorta, and the posterior cardinal vein in zebrafish embryos. Both in vitro and in vivo AA-PMe surpassed AA in its ability to block angiogenesis by suppressing VEGF-induced phosphorylation of VEGFR2 and disrupting downstream extracellular regulated protein kinase and AKT signaling.

Conclusion

For the first time, this study reveals that AA-PMe acts as a potent VEGFR2 kinase inhibitor and exerts powerful antiangiogenic activity, suggesting it to be a promising therapeutic candidate for further research.

Utility of Ultrasound in the Diagnosis, Treatment, and Follow-up of Prostate Cancer: State of the Art

Prostate cancer screening currently consists of serum prostate-specific antigen and digital rectal examination, followed by transrectal ultrasound-guided biopsy for diagnostic confirmation. Although the current paradigm of prostate cancer screening has led to a decrease in advanced disease and cancer-related mortality, these techniques have limitations in terms of sensitivity and specificity, resulting in missed cancers that are clinically significant and the overdetection of clinically insignificant cancers. New imaging techniques and technologies are required to improve the detection of prostate cancer. This article summarizes the use of novel ultrasound techniques and technologies in the detection, biopsy, and treatment of prostate cancer.

Endocrine Gland-Derived Vascular Endothelial Growth Factor/Prokineticin-1 in Cancer Development and Tumor Angiogenesis

A lot of data suggests endocrine gland-derived vascular endothelial growth factor (EG-VEGF) to be restricted to endocrine glands and to some endocrine-dependent organs. Many evidences show that EG-VEGF stimulates angiogenesis and cell proliferation, although it is not a member of the VEGF family. At the time, a lot of data regarding the role of this growth factor in normal development are available. However, controversial results have been published in the case of pathological conditions and particularly in malignant tumors. Thus, our present paper has been focused on the role of EG-VEGF in normal tissues and various malignant tumors and their angiogenic processes.

Ganoderma Lucidum(Reishi) in Cancer Treatment

The popular edible mushroom Ganoderma lucidum(Reishi) has been widely used for the general promotion of health and longevity in Asian countries. The dried powder of Ganoderma lucidumwas popular as a cancer chemotherapy agent in ancient China. The authors recently demonstrated that Ganoderma luciduminhibits constitutively active transcription factors nuclear factor kappa B (NF-.B) and AP-1, which resulted in the inhibition of expression of urokinasetype plasminogen activator (uPA) and its receptor uPAR. Ganoderma lucidumalso suppressed cell adhesion and cell migration of highly invasive breast and prostate cancer cells, suggesting its potency to reduce tumor invasiveness. Thus, Ganoderma lucidumclearly demonstrates anticancer activity in experiments with cancer cells and has possible therapeutic potential as a dietary supplement for an alternative therapy for breast and prostate cancer. However, because of the availability of Ganoderma lucidum from different sources, it is advisable to test its biologic activity.

AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells

Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G₀/G₁ phase and blocked G₁-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy.

Transrectal Elastographic Biopsy and Contrast-Enhanced Transrectal Biopsy May Offer Improvements Over the Current Transrectal Systemic Biopsy Technique

Prostate cancer is a common cause of cancer-related death of men in the United States. The purpose of this review is to compare the validity of transrectal ultrasound–guided systemic biopsy with contrast-enhanced transrectal ultrasound–guided systemic biopsy and transrectal elastography–guided systemic biopsy for the detection of prostate cancer. Adding contrast-enhanced or transrectal elastography core targeting to transrectal ultrasound–guided biopsy is a feasible approach to increase detection rates of higher-grade prostate cancers. Because contrast-enhanced imaging of the prostate is not approved for use in the United States, elastography is the most effective sonographic solution to improve prostate cancer detection with current screening techniques.

Fibroblasts prolong serum prostate-specific antigen decline after androgen deprivation therapy in prostate cancer

In patients with prostate cancer (PCa), serum prostate-specific antigen (PSA) is a useful marker for evaluating the effects of androgen deprivation therapy (ADT). Intuitively, most urologists expect that a more rapid PSA decline in response to ADT would be positively associated with extended survival. Recently, we have reported that prolonged gradual serum PSA decline after ADT is strongly associated with favorable prognosis in PCa patients, however, the mechanism remains unknown. We investigated the role of fibroblasts in serum PSA decline after ADT. We performed in vitro experiments using androgen-sensitive, androgen receptor (AR)-positive prostate epithelial cell lines (LNCaP, 22Rv1, and RWPE-1 cells), commercially available prostate stromal cells (PrSC), and primary cultures of prostate fibroblasts (pcPrFs). In LNCaP and 22Rv1 cells, PSA production was increased by co-culture with fibroblasts under androgen-deprived conditions. In an in vivo model using LNCaP cells, serum PSA declined rapidly after ADT becoming undetectable within 14 days in mice inoculated with LNCaP cells alone. In contrast, when LNCaP cells were co-inoculated with fibroblasts, serum PSA levels were still high on 14 days post ADT and did not drop to undetectable levels until 21 days post ADT. Tumor volumes and Ki67 labeling indices were not altered between days 14 and 21 post ADT in mice inoculated with LNCaP cells; however, those in mice inoculated with LNCaP cells plus fibroblasts decreased gradually. PSA protein was detected in all tumors on 21 days post ADT by immunohistochemical staining. Microvessel densities were higher on 14 days post ADT for tumors from mice inoculated with LNCaP cells plus fibroblasts as compared with LNCaP cells alone. In summary, co-inoculation of fibroblasts with LNCaP cells prolonged serum PSA decline after ADT and enhanced the efficacy of ADT. Prolonged serum PSA decline may indicate the presence of protective fibroblasts that preserve the AR dependence of PCa cells, improving treatment efficacy.

Design, synthesis and biological evaluation of indazole–pyrimidine based derivatives as anticancer agents with anti-angiogenic and antiproliferative activities

Three series of novel indazole–pyrimidine based compounds were designed, synthesized and biologically evaluated as VEGFR-2 kinase inhibitors.

Therapeutic potential of targeting protein for Xklp2 silencing for pancreatic cancer

The targeting protein for Xklp2 (TPX2) is a microtubule- and, cell cycle-associated protein who’s overexpression has been reported in various malignancies. In this study, we verified the overexpression of TPX2 in both surgically resected specimens of pancreatic cancer and multiple pancreatic cancer cell lines. Subsequently, we found that TPX2 siRNA effectively suppressed the proliferation of pancreatic cancer cells in culture, and the direct injection of TPX2 siRNA into subcutaneously implanted pancreatic cancer cells in nude mice revealed antiproliferative effects. These results implied a therapeutic potential of TPX2 siRNA in pancreatic cancer. Among 56 angiogenesis-related factors examined using angiogenesis arrays, the average protein levels of insulin-like growth factor-binding protein-3 (IGFBP-3) were significantly higher in TPX2 siRNA-treated tumors than in the Control siRNA-treated tumors. Moreover, we demonstrated that CD34-positive microvessels were significantly reduced in tumors treated with TPX2 siRNA compared to tumors that treated with Control siRNA. The attenuated expression of CD34 in TPX2 siRNA-treated tumors coincided with the overexpression of IGFBP-3. These results indicated that TPX2 has an impact on tumor angiogenesis in pancreatic cancer. The results also implied that the antiangiogenic effect observed in TPX2 siRNA-treated pancreatic cancer cells may be partly explained by the upregulation of IGFBP-3.

Randomized phase II study of nintedanib in metastatic castration-resistant prostate cancer postdocetaxel

This open-label, phase II trial assessed the efficacy and safety of two doses of nintedanib, a triple angiokinase inhibitor targeting vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor signaling, in patients with metastatic castration-resistant prostate cancer (mCRPC) following progression on docetaxel-based regimens. Patients were randomized to nintedanib 150 mg (arm A, n=40) or 250 mg (arm B, n=41) twice daily for 6 months unless disease progression or adverse events (AEs) led to discontinuation. The primary endpoint was the prostate-specific antigen (PSA) response rate (confirmed PSA decline of ≥20% from baseline). Eighty-one patients were enrolled. The PSA response rate was 0% (0/32) in arm A versus 11.1% (4/36) in arm B (P=0.12); 5.6% of patients (2/36) in arm B showed a PSA reduction of at least 50%. In arm B, the rate of PSA increase was significantly decelerated on treatment versus before treatment (P=0.002). The median progression-free survival was 73.5 and 76.0 days for arm A and arm B, respectively (P=0.3). AEs included gastrointestinal disorders, asthenia, hypertension, and reversible elevated transaminases. The incidence of drug-related serious AEs (no drug-related deaths) was 20.0% (arm A) and 24.4% (arm B). The primary endpoint was not met. Nintedanib (250 mg) showed only modest activity with manageable AEs in patients with mCRPC post-docetaxel.

Prostatic angiogenic responses in late life: antiangiogenic therapy influences and relation with the glandular microenvironment in the transgenic adenocarcinoma of mouse prostate (TRAMP) model

BACKGROUND

Aging is considered one of the main predisposing factors for the development of prostate malignancies. Angiogenesis is fundamental for tumor growth and its inhibition represents a promising therapeutic approach in cancer treatment. Thus, we sought to determine angiogenic responses and the effects of antiangiogenic therapy in the mouse prostate during late life, comparing these findings with the prostatic microenvironment in the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model.

METHODS

Male mice (52 week-old FVB) were submitted to treatments with SU5416 (6 mg/kg; i.p.) and/or TNP-470 (15 mg/kg; s.c.). Finasteride was administered (20 mg/kg; s.c.), alone or in association to both inhibitors. The dorsolateral prostate was collected for VEGF, HIF-1α, FGF-2 and endostatin immunohistochemical and Western Blotting analyses and for microvessel density (MVD) count.

RESULTS

Senescence led to increased MVD and VEGF, HIF-1α and FGF-2 protein levels in the prostatic microenvironment, similarly to what was observed in TRAMP mice prostate. The angiogenic process was impaired in all the treated groups, demonstrating significantly decreased MVD. Antiangiogenic and/or finasteride treatments resulted in decreased VEGF and HIF-1α levels, especially following TNP-470 administration, either alone or associated to SU5416. The combination of these agents resulted in increased endostatin levels, regardless of the presence of finasteride.

CONCLUSIONS

Prostatic angiogenesis stimulation during senescence favored the development of neoplastic lesions, considering the pro-angiogenic microenvironment as a common aspect also observed during cancer progression in TRAMP mice. The combined antiangiogenic therapy was more efficient, leading to enhanced imbalance towards angiogenic inhibition in the organ. Finally, finasteride administration might secondarily upregulate the expression of pro-angiogenic factors, pointing to the harmful effects of this therapy.

Association between single-nucleotide polymorphisms in growth factor genes and quality of life in men with prostate cancer and the general population

PURPOSE

Improved survival for men with prostate cancer has led to increased attention to factors influencing quality of life (QOL). As protein levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor 1 (IGF-1) have been reported to be associated with QOL in people with cancer, we sought to identify whether single-nucleotide polymorphisms (SNPs) of these genes were associated with QOL in men with prostate cancer.

METHODS

Multiple linear regression of two data sets (including approximately 750 men newly diagnosed with prostate cancer and 550 men from the general population) was used to investigate SNPs of VEGF and IGF-1 (10 SNPs in total) for associations with QOL (measured by the SF-36v2 health survey).

RESULTS

Men with prostate cancer who carried the minor 'T' allele for IGF-1 SNP rs35767 had higher mean Role-Physical scale scores (≥0.3 SD) compared to non-carriers (p < 0.05). While this association was not identified in men from the general population, one IGF-1 SNP rs7965399 was associated with higher mean Bodily Pain scale scores in men from the general population that was not found in men with prostate cancer. Men from the general population who carried the rare 'C' allele had higher mean Bodily Pain scale scores (≥0.3 SD) than non-carriers (p < 0.05).

CONCLUSIONS

Through identifying SNPs that are associated with QOL in men with prostate cancer and men from the general population, this study adds to the mapping of complex interrelationships that influence QOL and suggests a role for IGF-I in physical QOL outcomes. Future research may identify biomarkers associated with increased risk of poor QOL that could assist in the provision of pre-emptive support for those identified at risk.

Combined therapeutic effects of vinblastine and Astragalus saponins in human colon cancer cells and tumor xenograft via inhibition of tumor growth and proangiogenic factors

Our previous study had demonstrated that Astragalus saponins (AST) could reduce the side effects of orthodox chemotherapeutic drugs, while concurrently promote antitumor activity. In the present study, we attempted to investigate the potential synergistic anticarcinogenic effects of AST and a vinca alkaloid vinblastine (VBL). Reduced expression of key proangiogenic and metastatic factors including VEGF, bFGF, metalloproteinase (MMP)-2, and MMP-9 was detected in VBL-treated colon cancer cells, with further downregulation by combined VBL/AST treatment. Subsequently, VBL or AST decreased LoVo cell invasiveness, with further reduction when the drugs were cotreated. Significant growth inhibition and cell cycle arrest at G2/M phase were achieved by either drug treatment with apparent synergistic effects. VBL-induced apoptosis was confirmed but found to be unrelated to induction of the novel apoptotic protein NSAID-activated gene 1. In vivo study in tumor xenograft indicates that combined VBL/AST treatment resulted in sustained regression of tumor growth, with attenuation of the neutropenic and anemic effects of VBL. In addition, downregulation of proangiogenic and proliferative factors was also visualized, with boosting effect by combined drug treatment. These findings have provided evidence that AST combined with adjuvant chemotherapeutics like VBL could alleviate cancer development through diversified modes of action, including the regulation of angiogenesis.

Antiangiogenic therapy effects on age-associated matrix metalloproteinase-9 (MMP-9) and insulin-like growth factor receptor-1 (IGFR-1) responses: a comparative study of prostate disorders in aged and TRAMP mice

Senescence is associated with hormonal imbalance and prostatic disorders. Angiogenesis is fundamental for the progression of malignant lesions and is a promising target for prostate cancer treatment. The aim was to characterize matrix metalloproteinase-9 (MMP-9) and insulin-like growth factor receptor-1 (IGFR-1) responses in the prostate during senescence and following antiangiogenic and/or androgen ablation therapies, comparing them to cancer progression features in TRAMP mice. Aged male mice (52-week-old FVB) were submitted to antiangiogenic treatments with SU5416 (6 mg/kg; i.p.) and/or TNP-470 (15 mg/kg; s.c). Finasteride (20 mg/kg; s.c.) was administered alone or associated to both inhibitors. Dorsolateral prostate was collected for light microscopy, and immunohistochemistry and Western blotting collected for MMP-9 and IGFR-1. Senescence led to inflammation and different proliferative lesions in the prostate, as well as to increased MMP-9 and IGFR-1, resembling TRAMP mice prostatic microenvironment. Antiangiogenic therapies promoted recovery and/or interruption of age-associated alterations, presenting differential effects on the molecules studied. SU5416 acted mainly on MMP-9, whereas TNP-470 showed its best influence on IGFR-1 levels. Finasteride administration, alone or in combination with antiangiogenic agents, also resulted in regression of inflammation and neoplastic lesions, besides having a negative modulatory effect on both MMP-9 and IGFR-1. We concluded that stimulated tissue remodeling and proliferative processes during senescence predisposed the prostate to malignant disorders. The combination of different agents was more effective to minimize prostatic imbalance during this period, probably due to the differential action of each drug on factors involved in cell proliferation and extracellular matrix remodeling, resulting in a broader spectrum of effects following the combined treatment.

A novel aptamer functionalized CuInS2 quantum dots probe for daunorubicin sensing and near infrared imaging of prostate cancer cells

In this paper, a novel daunorubicin (DNR)-loaded MUC1 aptamer-near infrared (NIR) CuInS2 quantum dot (DNR-MUC1-QDs) conjugates were developed, which can be used as a targeted cancer imaging and sensing system. After the NIR CuInS2 QDs conjugated with the MUC1 aptamer-(CGA)7, DNR can intercalate into the double-stranded CG sequence of the MUC1-QDs. The incorporation of multiple CG sequences within the stem of the aptamers may further increase the loading efficiency of DNR on these conjugates. DNR-MUC1-QDs can be used to target prostate cancer cells. We evaluated the capacity of MUC1-CuInS2 QDs for delivering DNR to cancer cells in vitro, and its binding affinity to MUC1-positive and MUC1-negative cells. This novel aptamer functionalized QDs bio-nano-system can not only deliver DNR to the targeted prostate cancer cells, but also can sense DNR by the change of photoluminescence intensity of CuInS2 QDs, which concurrently images the cancer cells. The quenched fluorescence intensity of MUC1-QDs was proportional to the concentration of DNR in the concentration ranges of 33-88 nmol L(-1). The detection limit (LOD) for DNR was 19 nmol L(-1). We demonstrate the specificity and sensitivity of this DNR-MUC1-QDs probe as a cancer cell imaging, therapy and sensing system in vitro.

Suppression of DHT-induced paracrine stimulation of endothelial cell growth by estrogens via prostate cancer cells

BACKGROUND

Androgen modulation of angiogenesis in prostate cancer may be not directly mediated by androgen receptor (AR) as AR is not detected in the prostatic endothelial cells.

METHODS

We examined the paracrine stimulation of cell proliferation by prostate tumor cells and its modulation by androgen and estrogens in a murine endothelial cell line (MEC) that does not express AR.

RESULTS

Tumor cell conditioned media (TCM) collected from LAPC-4 or LNCaP prostatic tumor cells produced a time- and concentration-dependent induction of cell growth in MECs, which was parallel to the VEGF concentration in the TCM. This TCM-induced cell growth in MECs was enhanced by the treatment of prostatic tumor cells with dihydrotestosterone (DHT). Both the TCM-stimulation and DHT-enhancement effects in MECs were completely blocked by SU5416, a specific VEGF receptor antagonist. Co-administration of 17α-estradiol or 17β-estradiol with DHT in prostatic tumor cells completely inhibited the DHT-enhancement effect while treatment with DHT, 17α-estradiol or 17β-estradiol did not produce any significant direct effect in MECs. Moreover, administration of 17α-estradiol or 17β-estradiol in xenograft animals with LAPC-4 or LNCaP prostate tumor significantly decreased the microvessel number in the tumor tissues.

CONCLUSIONS

Our study indicated that prostate tumor cells regulate endothelial cell growth through a paracrine mechanism, which is mainly mediated by VEGF; and DHT is able to modulate endothelial cell growth via tumor cells, which is inhibited by 17α-estradiol and 17β-estradiol. Thus, both17α-estradiol and 17β-estradiol are potential agents for anti-angiogenesis therapy in androgen-responsive prostate cancer.

Vascular endothelial growth factor (VEGF) expression in locally advanced prostate cancer: secondary analysis of radiation therapy oncology group (RTOG) 8610

Background

Angiogenesis is a key element in solid-tumor growth, invasion, and metastasis. VEGF is among the most potent angiogenic factor thus far detected. The aim of the present study is to explore the potential of VEGF (also known as VEGF-A) as a prognostic and predictive biomarker among men with locally advanced prostate cancer.

Methods

The analysis was performed using patients enrolled on RTOG 8610, a phase III randomized control trial of radiation therapy alone (Arm 1) versus short-term neoadjuvant and concurrent androgen deprivation and radiation therapy (Arm 2) in men with locally advanced prostate carcinoma. Tissue samples were obtained from the RTOG tissue repository. Hematoxylin and eosin slides were reviewed, and paraffin blocks were immunohistochemically stained for VEGF expression and graded by Intensity score (0–3). Cox or Fine and Gray’s proportional hazards models were used.

Results

Sufficient pathologic material was available from 103 (23%) of the 456 analyzable patients enrolled in the RTOG 8610 study. There were no statistically significant differences in the pre-treatment characteristics between the patient groups with and without VEGF intensity data. Median follow-up for all surviving patients with VEGF intensity data is 12.2 years. Univariate and multivariate analyses demonstrated no statistically significant correlation between the intensity of VEGF expression and overall survival, distant metastasis, local progression, disease-free survival, or biochemical failure. VEGF expression was also not statistically significantly associated with any of the endpoints when analyzed by treatment arm.

Conclusions

This study revealed no statistically significant prognostic or predictive value of VEGF expression for locally advanced prostate cancer. This analysis is among one of the largest sample bases with long-term follow-up in a well-characterized patient population. There is an urgent need to establish multidisciplinary initiatives for coordinating further research in the area of human prostate cancer biomarkers.

Validation of a multiplex immunoassay for serum angiogenic factors as biomarkers for aggressive prostate cancer

BACKGROUND

Assays used for discovery of biomarkers should be robust and high-throughput, capable of analyzing a sufficiently large number of samples over a sufficiently long period of time with good precision.

METHODS

We evaluated the analytical performance of the Bio-Plex Pro™ Human Cancer Biomarker Panel 1, a 16-plex multiplex immunoassay, in serum for composite profiling of angiogenic factors. Because prostate cancer progression and metastasis are pathological events closely linked to angiogenesis, serum angiogenic factors are ideal candidates as prognostic biomarkers.

RESULTS

Our 5-day evaluation indicated that all 16 assays in the panel had good reproducibility (total precisions over 5 independent plates in 5 days of <20%), adequate sensitivity (LOQs of majority of the assays less than 100 pg/ml), and wide dynamic ranges (linearity of majority of the assays spanning across 3 logs in concentrations).

CONCLUSIONS

Applying the panel to sera from prostate cancer patients with Gleason scores of 6, 7, 8-10, tumor stages that correlated with clinical outcome, we identified that the levels of sTIE-2, a soluble form of the transmembrane tyrosine kinase receptor for angiopoietins, were increased in patients with Gleason score of 8-10. Future studies are necessary to determine whether sTIE-2 could be used as a prognostic biomarker for identifying aggressive prostate cancer.

Insulin-like growth factor binding protein-3 suppresses vascular endothelial growth factor expression and tumor angiogenesis in head and neck squamous cell carcinoma

Angiogenesis, the process by which new blood vessels are recruited to existing ones, is essential for tumor development. Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3), which modulates bioavailability of IGF, has been studied for its potential role in angiogenesis during tissue regeneration and cancer development. In this study, we assessed the role of IGFBP-3 in tumor angiogenesis in head and neck squamous cell carcinoma (HNSCC) and human umbilical vein endothelial cells (HUVECs) using adenoviral (Ad-BP3) and recombinant (rBP3) IGFBP-3. Using an in vivo orthotopic tongue tumor model, we confirmed that both Ad-BP3 and rBP3 suppress the growth of UMSCC38 HNSCC cells in vivo. Ad-BP3 inhibited vascularization in tongue tumors and chorio-allantoic membrane, and suppressed angiogenesis-stimulating activities in UMSCC38 cells. In HUVECs, Ad-BP3 decreased migration, invasion, and tube formation. rBP3 also suppressed production of vascular endothelial growth factor (VEGF) in HUVECs and UMSCC38 cells. IGFBP-3-GGG, a mutant IGFBP-3 with loss of IGF binding capacity, suppressed VEGF production. In addition, we found that IGFBP-3 suppressed VEGF expression, even in mouse embryonic fibroblasts from an IGF-1R-null mouse. Finally, we demonstrated that IGFBP-3-GGG inhibits tumor angiogenesis and growth to the same degree as wild-type IGFBP-3. Taken together, these results support the hypothesis that IGFBP-3 has anti-angiogenic activity in HNSCC, at least in part due to IGF-independent suppression of VEGF production from vascular endothelial cells and cancer cells.

Inhibition of androgen-responsive LNCaP prostate cancer cell tumor xenograft growth by dietary phenethyl isothiocyanate correlates with decreased angiogenesis and inhibition of cell attachment

Phenethyl isothiocyanate (PEITC) is a candidate anticancer compound found in certain cruciferous vegetables. In our tumor cell xenograft model, dietary administration of PEITC (100–150 mg/kg body weight/d) inhibited androgen-responsive LNCaP human prostate cancer cell tumor growth. We found that dietary treatment with PEITC significantly inhibited tumor platelet/endothelial cell adhesion molecule (PECAM-1/CD31) expression, a marker of angiogenesis. By contrast, we did not find the inhibitory effects of PEITC on tumor growth to be associated with alteration of specific markers for apoptosis, cell proliferation or androgen receptor-mediated pathways. Consistent with in vivo results, PEITC exerted little effects on cell proliferation, cell cycle and androgen-dependent pathways. Interestingly, PEITC significantly attenuated LNCaP cell plating efficiency that correlated with inhibition of integrin family proteins integrin β1, α2 and α6 mRNA expression. Thus, PEITC may be a dietary factor that inhibits androgen-responsive prostate tumor growth indirectly by selectively targeting factors involved in the tumor microenvironment.

The angiogenic switch for vascular endothelial growth factor-A and cyclooxygenase-2 in prostate carcinoma: correlation with microvessel density, androgen receptor content and Gleason grade

OBJECTIVE

Angiogenesis is essential for tumor growth and metastasis; however, angiogenic factors are not uniformly expressed in prostate carcinoma. Our aim was to determine the expression of vascular endothelial growth factor-A (VEGF-A) and cyclooxygenase-2 (COX-2) in prostate carcinomas in relation to intratumoral microvessel density (MVD), tumor grade and androgen receptor (AR) status.

MATERIALS AND METHODS

The expression of AR, VEGF-A and COX-2 was immunohistochemically evaluated in 24 benign prostatic hyperplasia (BPH) and 139 prostate carcinoma cases. MVD was evaluated by CD34 immunostaining.

RESULTS

Nuclear AR expression was inversely related to tumor grade (p < 0.001). MVD was strongly related to tumor grade, VEGF-A and COX-2 (p < 0.001 in all comparisons). VEGF-A expression increased with tumor grade (p < 0.01) and was inversely related to stromal AR expression. COX-2 was present in both BPH and prostate carcinoma, but its expression increased with tumor grade (p < 0.01). High-grade neoplasms presented low-to-moderate VEGF staining intensity compared to strong COX-2 expression.

CONCLUSIONS

Both VEGF-A and COX-2 expression is positively correlated with tumor grade and MVD. However, in Gleason 8-10 tumors, VEGF expression is moderate while COX-2 immunostaining is intense, suggesting a possible switch in the role of these two angiogenic factors in poorly differentiated neoplasms.

Asiatic acid inhibits pro-angiogenic effects of VEGF and human gliomas in endothelial cell culture models

Malignant gliomas are one of the most devastating and incurable tumors. Sustained excessive angiogenesis by glioma cells is the major reason for their uncontrolled growth and resistance toward conventional therapies resulting in high mortality. Therefore, targeting angiogenesis should be a logical strategy to prevent or control glioma cell growth. Earlier studies have shown that Asiatic Acid (AsA), a pentacyclic triterpenoid, is effective against glioma and other cancer cells; however, its efficacy against angiogenesis remains unknown. In the present study, we examined the anti-angiogenic efficacy of AsA using human umbilical vein endothelial cells (HUVEC) and human brain microvascular endothelial cells (HBMEC). Our results showed that AsA (5–20 µM) inhibits HUVEC growth and induces apoptotic cell death by activating caspases (3 and 9) and modulating the expression of apoptosis regulators Bad, survivin and pAkt-ser473. Further, AsA showed a dose-dependent inhibition of HUVEC migration, invasion and capillary tube formation, and disintegrated preformed capillary network. AsA also inhibited the VEGF-stimulated growth and capillary tube formation by HUVEC and HBMEC. Next, we analyzed the angiogenic potential of conditioned media collected from human glioma LN18 and U87-MG cells treated with either DMSO (control conditioned media, CCM) or AsA 20 µM (AsA20 conditioned media, AsA20CM). CCM from glioma cells significantly enhanced the capillary tube formation in both HUVEC and HBMEC, while capillary tube formation in both endothelial cell lines was greatly compromised in the presence of AsA20CM. Consistent with these results, VEGF expression was lesser in AsA20CM compared to CCM, and indeed AsA strongly inhibited VEGF level (both cellular and secreted) in glioma cells. AsA also showed dose-dependent anti-angiogenic efficacy in Matrigel plug assay, and inhibited the glioma cells potential to attract HUVEC/HBMEC. Overall, the present study clearly showed the strong anti-angiogenic potential of AsA and suggests its usefulness against malignant gliomas.

The Aqueous Soluble Polyphenolic Fraction of Psidium guajava Leaves Exhibits Potent Anti-Angiogenesis and Anti-Migration Actions on DU145 Cells

The aqueous extract of Psidium guajava budding leaves (PE) bears an extremely high content of polyphenolic and isoflavonoids. Whether it could be used as an anti-tumor chemopreventive in view of anti-angiogenesis and anti-migration, we performed the assay methods including the MTT assay to examine the cell viability; the ELISA assay to test the expressions of VEGF, IL-6 and IL-8; the western blot analysis to detect TIMP-2; the gelatinolytic zymography to follow the expression of MMPs; the wound scratch assay to examine the migration capability; and the chicken chorioallantoic membrane assay to detect the suppressive angiogenesis. Results indicated that the IC50 of PE for DU145 cells was ∼0.57 mg ml(-1). In addition, PE effectively inhibited the expressions of VEGF, IL-6 and IL-8 cytokines, and MMP-2 and MMP-9, and simultaneously activated TIMP-2 and suppressed the cell migration and the angiogenesis. Conclusively, PE potentially possesses a strong anti-DU145 effect. Thus, clinically it owns the potential to be used as an effective adjuvant anti-cancer chemopreventive.

Antiangiogenic antitumor activities of IGFBP-3 are mediated by IGF-independent suppression of Erk1/2 activation and Egr-1-mediated transcriptional events

Most antiangiogenic therapies currently being evaluated in clinical trials target the vascular endothelial growth factor pathway; however, the tumor vasculature can acquire resistance to vascular endothelial growth factor-targeted therapy by shifting to other angiogenesis mechanisms. Insulin-like growth factor binding protein-3 (IGFBP-3) has been reported to suppress tumor growth and angiogenesis by both IGF-dependent and IGF-independent mechanisms; however, understanding of its IGF-independent mechanisms is limited. We observed that IGFBP-3 blocked tumor angiogenesis and growth in non-small cell lung cancer and head and neck squamous cell carcinoma. Conditioned media from an IGFBP-3-treated non-small cell lung cancer cell line displayed a significantly decreased capacity to induce HUVEC proliferation and aortic sprouting. In cancer cells, IGFBP-3 directly interacted with Erk1/2, leading to inactivation of Erk1/2 and Elk-1, and suppressed transcription of early growth response protein 1 and its target genes, basic fibroblast growth factor and platelet-derived growth factor. These data suggest that IGF-independent Erk1/2 inactivation and decreased IGFBP-3-induced Egr-1 expression block the autocrine and paracrine loops of angiogenic factors in vascular endothelial and cancer cells. Together, these findings provide a molecular framework of IGFBP-3's IGF-independent antiangiogenic antitumor activities. Future studies are needed for development of IGFBP-3 as a new line of antiangiogengic cancer drug.

Control of tumor and microenvironment cross-talk by miR-15a and miR-16 in prostate cancer

The interaction between cancer cells and microenvironment has a critical role in tumor development and progression. Although microRNAs regulate all the major biological mechanisms, their influence on tumor microenvironment is largely unexplored. Here, we investigate the role of microRNAs in the tumor-supportive capacity of stromal cells. We demonstrated that miR-15 and miR-16 are downregulated in fibroblasts surrounding the prostate tumors of the majority of 23 patients analyzed. Such downregulation of miR-15 and miR-16 in cancer-associated fibroblasts (CAFs) promoted tumor growth and progression through the reduced post-transcriptional repression of Fgf-2 and its receptor Fgfr1, which act on both stromal and tumor cells to enhance cancer cell survival, proliferation and migration. Moreover, reconstitution of miR-15 and miR-16 impaired considerably the tumor-supportive capability of stromal cells in vitro and in vivo. Our data suggest a molecular circuitry in which miR-15 and miR-16 and their correlated targets cooperate to promote tumor expansion and invasiveness through the concurrent activity on stromal and cancer cells, thus providing further support to the development of therapies aimed at reconstituting miR-15 and miR-16 in advanced prostate cancer.

Comparison of real-time sonoelastography with T2-weighted endorectal magnetic resonance imaging for prostate cancer detection

OBJECTIVES

The purpose of this study was to compare the value of real-time sonoelastography with T2-weighted endorectal magnetic resonance imaging (MRI) for prostate cancer detection.

METHODS

Thirty-three patients with an elevated prostate-specific antigen level were investigated with real-time sonoelastography and T2-weighted endorectal MRI for prostate cancer diagnosis before systematic prostate biopsy. Real-time sonoelastography was performed to assess prostate tissue elasticity, and hard areas were considered suspicious for prostate cancer. Low-signal intensity nodules on T2-weighted endorectal MRI were considered suspicious for prostate cancer. Imaging findings were assigned to 6 areas of the peripheral zone (sextants), and their cancer detection rates were compared.

RESULTS

Overall, prostate cancer was detected in 13 of 33 patients (39.4%). Both real-time sonoelastography and T2-weighted endorectal MRI detected 11 cancer-positive patients (84.6%). Real-time sonoelastography showed 27 suspicious lesions in 198 sextants, and 15 (55.6%) were cancer positive. T2-weighted endorectal MRI showed 31 suspicious lesions in 198 sextants, and 13 (40.6%) were cancer positive. These findings resulted in sensitivity rates and negative predictive values per patient of 84.6% and 86.7%, respectively, for sonoelastography and 84.6% and 83.3% for MRI. The per-sextant analysis showed sensitivity rates and negative predictive values of 57.7% and 93.6% for sonoelastography and 50.0% and 92.2% for MRI.

CONCLUSIONS

Real-time sonoelastography showed comparable results as T2-weighted endorectal MRI for prostate cancer detection.

Effect of combined hormonal and insulin therapy on the steroid hormone receptors and growth factors signalling in diabetic mice prostate

Diabetes causes harmful effects on prostatic morphology and function. However, there still are doubts about the occurrence of various diseases in the prostate, as well as abnormal angiogenesis in relation to diabetes. Thus, the aim of this study was to correlate and quantify the level of the steroid hormone receptors and the angiogenic and antiangiogenic factors in non-obese diabetic mice (Nod) after combined hormonal and insulin therapy. Sixty mice were divided into six groups after 20 days of diabetes: the control group received 0.9% NaCl, as did the diabetic group. The diabetic-insulin group received insulin, the diabetic-testosterone group received testosterone cypionate, the diabetic-oestrogen group received 17β-oestradiol, and the diabetic-insulin-testosterone-oestrogen group received insulin, testosterone and oestrogen simultaneously. After 20 days, the ventral lobe was processed for immunocytochemical and hormonal analyses. The results showed that the lowest serum testosterone and androgen receptor levels were found in the diabetic group and the highest testosterone and androgen receptor levels in the diabetic-insulin-testosterone-oestrogen group. The serum oestrogen level and its receptor showed changes opposite to those of testosterone and its receptor. The endostatin reactivity was mainly decreased in diabetic mice. The greatest IGFR-1 and VEGF reactivities occurred in diabetic mice. Thus, diabetes led to the prostatic hormonal imbalance, affecting molecular dynamics and angiogenesis in this organ. Combined insulin and steroid hormone therapy partially restored the hormonal and angiogenic imbalance caused by diabetes.

Mapping pro- and antiangiogenic factors on the surface of prostasomes of normal and malignant cell origin

BACKGROUND

Angiogenesis is the formation of new blood vessels by capillary sprouting from pre-existing vessels. Tumor growth is angiogenesis-dependent and the formation of new blood vessels is associated with the increased expression of angiogenic factors. Prostasomes are secretory granules produced, stored and released by the glandular epithelial cells of the prostate. We investigated the expression of selected angiogenic and anti-angiogenic factors on the surface of prostasomes of different origins as well as the direct effect of prostasomes on angiogenesis.

METHODS

VEGF, endothelin-1, endostatin, and thrombospondin-1 were determined on prostasomes from seminal fluid and human prostate cancer cell lines (DU145,PC-3,LNCaP) using different immunochemical techniques. Human dermal microvascular endothelial cells were incubated with seminal and DU145 cell-prostasomes and with radioactive thymidine. The effect of prostasomes on angiogenesis was judged by measuring the uptake of labeled thymidine. The presence of any deleterious effects of prostasomes on the endothelial cells was investigated using thymidine assay and confocal laser microscopy.

RESULTS

VEGF and endothelin-1 were determined on malignant cell-prostasomes (no difference between cell lines) but not determined on seminal prostasomes. The same applies for the expression of endostatin but with much higher expression on malignant cell-prostasomes with obvious differences between them. Seminal and DU145 cell-prostasomes were found to have anti-angiogenic effect which was more expressed by DU145 cell-prostasomes. No deleterious effect of prostasomes on endothelial function was detected using either thymidine assay or microscopy.

CONCLUSIONS

Prostasomes contain pro- and anti-angiogenic factors that function to counteract each other unless the impact from one side exceeds the other to bring about dysequilibrium.

CASPASE-3 and CD-34 expression in prostate adenocarcinoma

OBJECTIVE

1. To evaluate the percentage of caspase-3 and CD-34 expression on adenocarcinoma; 2. to quantify caspase-3 and CD-34 in tumor cells; 3. to verify the relationship between biomarkers and its malignancy; 4. to correlate biomarkers themselves.

METHODS

Thirty-eight human malignant prostate specimens, Gleason's score, were immunohistochemically stained for caspase-3 and CD-34 protein. Quantification was done under Samba 4000 Immuno System reading, yielding two variables: label index and optical density. Statistical analyses were based on cross-methods involving univariate and bivariate as well as correlation factors among independent variables.

RESULTS

Immunostaining was revealed in 25 plates for caspase-3 and 34 for CD-34. Caspase-3 expression for label index was over 50 in 76%, while for optical density was below 50 in 96%. CD-34 expression demonstrated label index over 50 in 59% and optical density below 50 in 56%. Correlation among expression and severity did not demonstrate to be statistically significant. There was no correlation between protein expression and Gleason's score.

CONCLUSION

1. Caspase-3 and CD-34 were present respectively in 73.5% and 100% of samples; 2. caspase-3 and CD-34 showed high expression regarding label index and low expression in optical density; 3. there was no statistical significance among expressions and tumor severity according to Gleason's score; 4. no significant correlation could be set between the biomarkers themselves.