Advances in combination of antiangiogenic agents targeting VEGF-binding and conventional chemotherapy and radiation for cancer treatment

The Effect of Stem Cells and Vascular Endothelial Growth Factor on Cancer Angiogenesis

The formation of new vessels from pre-existing vessels is known as angiogenesis. The process is controlled by stimuli and inhibitors. Angiogenesis starts as a result of the unbalance of these factors, where balance has a tendency toward the stimulus. One of the most important factors promoting angiogenesis is the vascular endothelial growth factor (VEGF). In addition to being involved in vascular regeneration in normal tissues, VEGF also takes part in tumor tissue angiogenesis. These factors affect endothelial cells (ECs) directly as well as differentiate tumor cells from endothelial cells and play an active role in tumor tissue angiogenesis. Angiogenesis partakes in the growth and proliferation of tumor tissue. Because anti-angiogenic treatment is favorable in existing cancer therapies, the potential benefits should be considered. One of these new therapies is cell therapy using mesenchymal stem cells (MSCs). Research on MSCs remains controversial because much of the earlier research on MSCs has shown their effectiveness, but more recent research has identified harmful effects of these cells. This article reviews the role of stem cells and their secretions in the angiogenesis of tumor tissues.

PET-CT evaluation of the curative effect of crizotinib on malignant myofibroblastoma with rare mutation of ALK R401: a case report and literature review

Objective

The purpose of this article is to explore the targeted treatment of malignant myofibroblastoma and evaluate the role of neoplasm metabolite markers in the evaluation of efficacy after targeted therapy.

Method

This report described a case of myofibroblastic sarcoma with rare mutation of ALK R401 in a 58-year-old man prescribed with crizotinib, to evaluate its curative effect by positron emission tomography coupled with computed tomography (PET-CT). After the progressive disease in the brain, bevacizumab combined with crizotinib was administered. The Response Evaluation Criteria in Solid Tumors (RECIST), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were used to assess the efficacy. The efficacy was assessed by comparing changes in MTV and TLG.

Result

After the treatment of crizotinib, the tumor volume was decreased. However, bevacizumab combined with crizotinib had not improved the prognosis. The change of MTV and TLG was consistent with the efficacy. The increase of MTV and TLG is an early indicator of the poor prognosis of patients.

Conclusion

The treatment of the crizotinib patient with the mutation of ALK R401 was effective. The values of MTV and TLG reflected the prognosis earlier than RECIST.

SH003 represses tumor angiogenesis by blocking VEGF binding to VEGFR2

Tumor angiogenesis is a key feature of cancer progression, because a tumor requires abundant oxygen and nutrition to grow. Here, we demonstrate that SH003, a mixed herbal extract containing Astragalus membranaceus (Am), Angelica gigas (Ag) and Trichosanthes Kirilowii Maximowicz (Tk), represses VEGF-induced tumor angiogenesis both in vitro and in vivo. SH003 inhibited VEGF-induced migration, invasion and tube formation in human umbilical vein endothelial cells (HUVEC) with no effect on the proliferation. SH003 reduced CD31-positive vessel numbers in tumor tissues and retarded tumor growth in our xenograft mouse tumor model, while SH003 did not affect pancreatic tumor cell viability. Consistently, SH003 inhibited VEGF-stimulated vascular permeability in ears and back skins. Moreover, SH003 inhibited VEGF-induced VEGFR2-dependent signaling by blocking VEGF binding to VEGFR2. Therefore, our data conclude that SH003 represses tumor angiogenesis by inhibiting VEGF-induced VEGFR2 activation, and suggest that SH003 may be useful for treating cancer.

Local controllability and optimal control for a model of combined anticancer therapy with control delays

We study some control properties of a class of two-compartmental models of response to anticancer treatment which combines anti-angiogenic and cytotoxic drugs and take into account multiple control delays. We formulate sufficient local controllability conditions for semilinear systems resulting from these models. The control delays are related to PK/PD effects and some clinical recommendations, e.g., normalization of the vascular network. The optimized protocols of the combined therapy for the model, considered as solutions to an optimal control problem with delays in control, are found using necessary conditions of optimality and numerical computations. Our numerical approach uses dicretization and nonlinear programming methods as well as the direct optimization of switching times. The structural sensitivity of the considered control properties and optimal solutions is also discussed.

Anti-angiogenic Therapy in Cancer: Downsides and New Pivots for Precision Medicine

Primary solid tumors originate close to pre-existing tissue vasculature, initially growing along such tissue blood vessels, and this phenomenon is important for the metastatic potential which frequently occurs in highly vascularized tissues. Unfortunately, preclinic and clinic anti-angiogenic approaches have not been very successful, and multiple factors have been found to contribute to toxicity and tumor resistance. Moreover, tumors can highlight intrinsic or acquired resistances, or show adaptation to the VEGF-targeted therapies. Furthermore, different mechanisms of vascularization, activation of alternative signaling pathways, and increased tumor aggressiveness make this context even more complex. On the other hand, it has to be considered that the transitional restoration of normal, not fenestrated, microvessels allows the drug to reach the tumor and act with the maximum efficiency. However, these effects are time-limited and different, depending on the various types of cancer, and clearly define a specific “normalization window.” So, new horizons in the therapeutic approaches consist on the treatment of the tumor with pro- (instead of anti-) angiogenic therapies, which could strengthen a network of well-structured blood vessels that facilitate the transport of the drug.

Strategies for optimizing the response of cancer and normal tissues to radiation

Approximately 50% of all patients with cancer receive radiation therapy at some point during the course of their treatment, and the majority of these patients are treated with curative intent. Despite recent advances in the planning of radiation treatment and the delivery of image-guided radiation therapy, acute toxicity and potential long-term side effects often limit the ability to deliver a sufficient dose of radiation to control tumours locally. In the past two decades, a better understanding of the hallmarks of cancer and the discovery of specific signalling pathways by which cells respond to radiation have provided new opportunities to design molecularly targeted therapies to increase the therapeutic window of radiation therapy. Here, we review efforts to develop approaches that could improve outcomes with radiation therapy by increasing the probability of tumour cure or by decreasing normal tissue toxicity.

Effects of biophysical parameters in enhancing radiation responses of prostate tumors with ultrasound-stimulated microbubbles

We show here that ultrasound-stimulated microbubbles can enhance cell death within tumors when combined with radiation. The aim of this study was to investigate how different ultrasound parameters, different microbubble concentrations and different radiation doses interact to enhance cell death. Prostate xenograft tumors (PC-3) in severe combined immunodeficiency mice were subjected to ultrasound treatment at various peak negative pressures (250, 570 and 750 kPa) at a center frequency of 500 kHz, different microbubble concentrations (8, 80 and 1000 μL/kg) and different radiation doses (0, 2 and 8 Gy). Twenty-four hours after treatment, tumors were excised and assessed for cell death. Histologic analyses revealed that increases in radiation dose, microbubble concentration and ultrasound pressure promoted apoptotic cell death and disruption within tumors by as much as 21%, 30% and 43%, respectively. Comparable increases in ceramide, a cell death mediator, were identified using immunohistochemistry. We also show here that even clinically used microbubble concentrations combined with ultrasound can induce significant enhancement of cell death.

Comparison of simple models of periodic protocols for combined anticancer therapy

Several simple ordinary differential equation (ODE) models of tumor growth taking into account the development of its vascular network are discussed. Different biological aspects are considered from the simplest model of Hahnfeldt et al. proposed in 1999 to a model which includes drug resistance of cancer cells to chemotherapy. Some of these models can be used in clinical oncology to optimize antiangiogenic and cytostatic drugs delivery so as to ensure maximum efficacy. Simple models of continuous and periodic protocols of combined therapy are implemented. Discussion on the dynamics of the models and their complexity is presented.

Antitumor effect of FP3 in a breast cancer xenograft model

FP3 is a novel vascular endothelial growth factor (VEGF) blocker proposed to have antiangiogenic properties. Previous studies revealed that FP3 is a new promising agent for treating human choroidal neovascularization (CNV)-associated age-associated macular degeneration (AMD) and has an inhibitory effect on VEGF-mediated proliferation and migration of human umbilical vein endothelial cells and VEGF-mediated vessel sprouting of the rat aortic ring in vitro. Previous studies have also revealed that FP3 has antitumor effects and antiangiogenic effects in a non-small cell lung cancer cell line (A549), as well as in patient-derived tumor tissue xenograft models of gastric cancer and colon carcinoma with lymphatic and hepatic metastases in nude mice. In the present study, the antitumor effect of FP3 in an MDA-MB-231 breast cancer xenograft model was investigated. Treatment with FP3 for 3 weeks significantly suppressed xenograft growth and this inhibition was associated with a significant decrease in angiogenesis and direct inhibition of tumor cells. The results of the present study indicate that FP3 inhibits breast cancer tumor growth via the indirect inhibition of angiogenesis as well as a direct effect on tumor cells.

Antitumor effects of FP3 in combination with capecitabine on PDTT xenograft models of primary colon carcinoma and related lymphatic and hepatic metastases

FP3 is an engineered protein which contains the extracellular domain 2 of VEGF receptor 1 (Flt-1) and extracellular domain 3 and 4 of VEGF receptor 2 (Flk-1, KDR) fused to the Fc portion of human immunoglobulin G 1. Previous studies demonstrated its antiangiogenic effects in vitro and in vivo, and its antitumor activity in vivo. In this study, patient-derived tumor tissue (PDTT) xenograft models of primary colon carcinoma and lymphatic and hepatic metastases were established for assessment of the antitumor activity of FP3 in combination with capecitabine. Xenografts were treated with FP3, capecitabine, alone or in combination. After tumor growth was confirmed, volume and microvessel density in tumors were evaluated. Levels of VEGF, and PCNA in the tumor were examined by immunohistonchamical staining, level of thymidine phosphorylase (TP) was examined by ELISA, and levels of related cell signaling pathways proteins expression were examined by western blotting. FP3 in combination with capecitabine showed significant antitumor activity in three xenograft models (primary colon carcinoma, lymphatic metastasis, and hepatic metastasis). The microvessel density in tumor tissues treated with FP3 in combination with capecitabine was lower than that of the control. Antitumor activity of FP3 in combination with capecitabine was significantly higher than that of each agent alone in three xenograft models (primary colon carcinoma, lymphatic metastasis, and hepatic metastasis). This study indicated that addition of FP3 to capecitabine significantly improved tumor growth inhibition in the PDTT xenograft models of primary colon carcinoma and lymphatic and hepatic metastases.

FP3: a novel VEGF blocker with antiangiogenic effects in vitro and antitumour effects in vivo

BACKGROUND Vascular endothelial growth factor (VEGF) is a critical promoter of blood vessel growth during embryonic development and neovascularisation in tumours. VEGF serves as a logical target for antiangiogenic cancer therapy because of its fundamental role in tumour angiogenesis. This study is to investigate the inhibitory effects of FP3, a novel VEGF blocker, on angiogenesis in vitro and tumour growth in vivo. METHODS The inhibitory effects of FP3 on angiogenesis in vitro were evaluated by using human umbilical vein endothelial cells (HUVECs) and rat aortic ring. The inhibitory effects of FP3 on tumour growth and angiogenesis in vivo were evaluated in a human non-small-cell lung cancer (NSCLC) cell line A549 tumour xenograft model with the methods of tumour growth regression assay and immunohistochemical staining, respectively. RESULTS In experiments with HUVECs, FP3 inhibited cell proliferation and migration. In rat aortic ring assay, FP3 suppressed VEGF-induced vessel sprouting. In tumour growth regression assay, FP3 significantly blocked the growth of A549 tumour in the subcutaneous tumour xenograft model and dramatically decreased the vessel density of tumour. CONCLUSIONS FP3 has excellent inhibitory effects on tumour angiogenesis both in vitro and in vivo, therefore it could be used as an effective antiangiogenic agent.

Antitumor effect of FP3 in a patient-derived tumor tissue xenograft model of gastric carcinoma through an antiangiogenic mechanism

FP3 (KH902/KH903) is a novel vascular endothelial growth factor (VEGF) blocker with antiangiogenic properties. Previous studies revealed that FP3, a humanized fusion protein that combines ligand binding elements from the extracellular domains of VEGF receptors 1 and 2 and the Fc portion of IgG1, has an inhibitory effect on the VEGF-mediated proliferation and migration of human umbilical vein endothelial cells, and VEGF-mediated vessel sprouting of rat aortic rings in vitro. Thus, FP3 was considered as a new promising agent in treating human choroidal neovascularization (CNV) caused by age-related macular degeneration (AMD). FP3 also has an antitumor effect in a non-small cell lung cancer cell line (A549) xenograft model in nude mice. However, little is known of the direct effects of FP3 on tumor vessels. In this study, we investigated the effects of FP3 on blood vessels in a patient-derived tumor tissue (PDTT) xenograft model of gastric carcinoma, using large tumors with established vasculature. Treatment with FP3 caused robust and early changes in endothelial cells and pericytes of vessels in the PDTT xenograft model. Vascular density decreased and vascular sprouting was suppressed by treatment with FP3. Pericytes did not degenerate to the same extent as endothelial cells, and those on surviving tumor vessels achieved a more normal phenotype. Our results revealed that FP3 has a direct and rapid antiangiogenic effect on tumor vessels, which was achieved mainly via regression of tumor vasculature, inhibition of new and recurrent vessel growth, and normalization of existing tumor vasculature.

Assessment of a novel VEGF targeted agent using patient-derived tumor tissue xenograft models of colon carcinoma with lymphatic and hepatic metastases

The lack of appropriate tumor models of primary tumors and corresponding metastases that can reliably predict for response to anticancer agents remains a major deficiency in the clinical practice of cancer therapy. It was the aim of our study to establish patient-derived tumor tissue (PDTT) xenograft models of colon carcinoma with lymphatic and hepatic metastases useful for testing of novel molecularly targeted agents. PDTT of primary colon carcinoma, lymphatic and hepatic metastases were used to create xenograft models. Hematoxylin and eosin staining, immunohistochemical staining, genome-wide gene expression analysis, pyrosequencing, qRT-PCR, and western blotting were used to determine the biological stability of the xenografts during serial transplantation compared with the original tumor tissues. Early passages of the PDTT xenograft models of primary colon carcinoma, lymphatic and hepatic metastases revealed a high degree of similarity with the original clinical tumor samples with regard to histology, immunohistochemistry, genes expression, and mutation status as well as mRNA expression. After we have ascertained that these xenografts models retained similar histopathological features and molecular signatures as the original tumors, drug sensitivities of the xenografts to a novel VEGF targeted agent, FP3 was evaluated. In this study, PDTT xenograft models of colon carcinoma with lymphatic and hepatic metastasis have been successfully established. They provide appropriate models for testing of novel molecularly targeted agents.

Protease-activated receptors in cancer: A systematic review

The traditional view of the role of proteases in tumor growth, progression and metastasis has significantly changed. Apart from their contribution to cancer progression, it is evident that a subclass of proteases, such as thrombin, serves as signal molecules controlling cell functions through the protease-activated receptors (PARs). Among the four types of PAR (PAR1-4; cloned and named in order of their discovery), PAR1, PAR3 and PAR4 are activated by thrombin, unlike PAR2, which is activated by trypsin-like serine proteases. Thrombin has been proven to be a significant factor in both the behavior of cancer in its involvement in hemostasis and blood coagulation. Thrombin is a key supporter of various cellular effects relevant to tumor growth and metastasis, as well as a potent activator of angiogenesis, which is essential for the growth and development of all solid tumor types. This review presents an overview of the role of PAR-mediated thrombin in angiogenesis and cancer, focusing on the ability of PAR1- and PAR4-mediated thrombin to affect tumorigenesis and angiogenesis.

A novel antiangiogenic approach for adjuvant therapy of pancreatic carcinoma

INTRODUCTION

Surgical therapy remains the only curative option for pancreatic ductal adenocarcinoma. But even after complete resection, almost all patients suffer from local tumor recurrence. Current standard adjuvant therapy with gemcitabine does not impressively affect the recurrence rate. The aim of this study was to evaluate a novel anti-angiogenic adjuvant treatment strategy by targeting the vascular endothelial growth factor receptor (VEGFR). We assayed the effects of a novel VEGFR inhibitor (ZK261991) on pancreatic carcinoma. ZK261991 is a highly selective and potent VEGFR-kinase inhibitor, which is orally available.

METHODS

We used a previously established nude mouse orthotopic pancreatic cancer resection model. Subcutaneous donor tumor fragments (1 mm(3)) derived from human pancreatic cancer cell lines HPAF-2 and AsPC-1 were implanted in the pancreatic tail of 48 nude mice. Fourteen days afterwards, all mice underwent a histologically confirmed curative tumor resection followed by daily adjuvant oral therapy with ZK261991 (50 mg/kg; n = 24) vs. placebo (n = 24). The mice were sacrificed after 12 weeks of therapy or in case of defined endpoints. All sacrificed mice underwent autopsy. A dissemination score (local and systemic tumor spread), size of recurrent tumor mass, survival, and weight loss/gain were surveyed.

RESULTS

Kaplan-Meier analysis of survival showed a significant benefit for mice treated with ZK261991 after HPAF-2 tumor resection: 83.8 days (95% CI 73.9-93.6) vs. 60.9 days (95% CI 48.9-73.0), p = 0.006. Adjuvant treatment with ZK261991 of AsPC-1-derived tumors showed a tendency towards a benefit compared to control but no significant difference: 75.8 days (95% CI 59.7-91.9) vs. 65.7 days (95% CI 51.6-79.7). There were no significant differences in dissemination score and size of recurrent tumor mass between the treatment groups.

CONCLUSION

Adjuvant anti-angiogenic therapy with the novel VEGFR-inhibitor ZK261991 resulted in a significant survival benefit after curative tumor resection in a clinically relevant orthotopic animal model of pancreatic cancer. Combination of anti-angiogenic treatment with cytotoxic agents may further improve the results of adjuvant therapy.