Bevacizumab enhances the therapeutic efficacy of Irinotecan against human head and neck squamous cell carcinoma xenografts

Vascularized tumor on a microfluidic chip to study mechanisms promoting tumor neovascularization and vascular targeted therapies

The cascade of events leading to tumor formation includes induction of a tumor supporting neovasculature, as a primary hallmark of cancer. Developing vasculature is difficult to evaluate in vivo but can be captured using microfluidic chip technology and patient derived cells. Herein, we established an on chip approach to investigate the mechanisms promoting tumor vascularization and vascular targeted therapies via co-culture of cancer spheroids and endothelial cells in a three dimensional environment. Methods: We investigated both, tumor neovascularization and therapy, via co-culture of human derived endothelial cells and adjacently localized metastatic renal cell carcinoma spheroids on a commercially available microfluidic chip system. Metastatic renal cell carcinoma spheroids adjacent to primary vessels model tumor, and induce vessels to sprout neovasculature towards the tumor. We monitored real time changes in vessel formation, probed the interactions of tumor and endothelial cells, and evaluated the role of important effectors in tumor vasculature. In addition to wild type endothelial cells, we evaluated endothelial cells that overexpress Prostate Specific Membrane Antigen (PSMA), that has emerged as a marker of tumor associated neovasculature. We characterized the process of neovascularization on the microfluidic chip stimulated by enhanced culture medium and the investigated metastatic renal cell carcinomas, and assessed endothelial cells responses to vascular targeted therapy with bevacizumab via confocal microscopy imaging. To emphasize the potential clinical relevance of metastatic renal cell carcinomas on chip, we compared therapy with bevacizumab on chip with an in vivo model of the same tumor. Results: Our model permitted real-time, high-resolution observation and assessment of tumor-induced angiogenesis, where endothelial cells sprouted towards the tumor and mimicked a vascular network. Bevacizumab, an antiangiogenic agent, disrupted interactions between vessels and tumors, destroying the vascular network. The on chip approach enabled assessment of endothelial cell biology, vessel's functionality, drug delivery, and molecular expression of PSMA. Conclusion: Observations in the vascularized tumor on chip permitted direct and conclusive quantification of vascular targeted therapies in weeks as opposed to months in a comparable animal model, and bridged the gap between in vitro and in vivo models.

Vascularized tumor on a microfluidic chip to study mechanisms promoting tumor neovascularization and vascular targeted therapies

The cascade of events leading to tumor formation includes induction of a tumor supporting neovasculature as a primary hallmark of cancer. Developing vasculature is difficult to evaluate in vivo but can be captured using microfluidic chip technology and patient derived cells. Herein, we established an on chip approach to investigate the mechanisms promoting tumor vascularization and vascular targeted therapies via co-culture of metastatic renal cell carcinoma spheroids and endothelial cells in a 3D environment. Our model permitted real-time, high-resolution observation and assessment of tumor-induced angiogenesis, where endothelial cells sprout towards the tumor and mimic a vascular network. Bevacizumab, an angiogenic inhibitor, disrupted interactions between vessels and tumors, destroying the vascular network. The on chip approach enabled assessment of endothelial cell biology, vessel's functionality, drug delivery, and molecular expression of PSMA. Finally, observations in the vascularized tumor on chip permitted direct and conclusive quantification of this therapy in weeks as opposed to months in a comparable animal model.

Teaser

Vascularized tumor on microfluidic chip provides opportunity to study targeted therapies and improves preclinical drug discovery.

New opportunities for RGD-engineered metal nanoparticles in cancer

The advent of nanotechnology has opened new possibilities for bioimaging. Metal nanoparticles (such as gold, silver, iron, copper, etc.) hold tremendous potential and offer enormous opportunities for imaging and diagnostics due to their broad optical characteristics, ease of manufacturing technique, and simple surface modification. The arginine-glycine-aspartate (RGD) peptide is a three-amino acid sequence that seems to have a considerably greater ability to adhere to integrin adhesion molecules that exclusively express on tumour cells. RGD peptides act as the efficient tailoring ligand with a variety of benefits including non-toxicity, greater precision, rapid clearance, etc. This review focuses on the possibility of non-invasive cancer imaging using metal nanoparticles with RGD assistance.

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

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

Antitumor effects of bevacizumab in combination with fluoropyrimidine drugs on human oral squamous cell carcinoma

Vascular endothelial growth factor (VEGF) serves an important role in new blood vessel formation or angiogenesis, which is a critical event in tumor growth and metastasis. Bevacizumab is a humanized monoclonal antibody against VEGF-A, whereas S-1 is a fluoropyrimidine antineoplastic agent that induces apoptosis in various types of cancer cells. The present study evaluated the antitumor effects of bevacizumab in combination with 5-fluorouracil (5-FU) or S-1 against oral squamous cell carcinoma (OSCC) in vitro and in vivo. Two human OSCC cell lines were used, namely the high VEGF-A-expressing HSC-2 cells and the low VEGF-A-expressing SAS cells. MTT assay was used to evaluate the effect of bevacizumab and/or 5-FU against HSC-2 and SAS cell proliferation. Additionally, the antitumor effect of bevacizumab was evaluated alone and in combination with S-1 against HSC-2 tumors in nude mice. S-1 (6.9 mg/kg/day) was administered orally every day for 3 weeks, and bevacizumab (5 ml/kg/day) was injected intraperitoneally twice per week for 3 weeks. Apoptotic cells in mouse tumors were detected using the TUNEL method, and cell proliferation and microvessel density (MVD) were determined by immunohistochemical staining of Ki-67 and CD31, respectively. Bevacizumab alone did not inhibit OSCC cell proliferation in vitro, and did not exhibit any synergistic inhibitory effect in combination with 5-FU in vitro. However, combined bevacizumab and S-1 therapy exerted synergistic and significant antitumor effects in vivo on HSC-2 tumor xenografts, and induced apoptosis in tumor cells. Furthermore, this combination therapy led to decreased MVD and cell proliferative abilities, as well as increased apoptosis in residual tumors. The present findings suggested that the bevacizumab plus S-1 combination therapy may exert antitumor effects in high VEGF-A-expressing OSCC cells.

Exosomal Delivery of AntagomiRs Targeting Viral and Cellular MicroRNAs Synergistically Inhibits Cancer Angiogenesis

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated cancer characterized by a high degree of recurrence, angiogenesis, and metastasis. The importance of alternative pro-angiogenesis pathways including viral factors has emerged after decades of directly targeting various signaling components. Using NPC as a model, we identified an essential oncogenic pathway underlying angiogenesis regulation that involves the inhibition of a tumor suppressor, Spry3, and its downstream targets by EBV-miR-BART10-5p (BART10-5p) and hsa-miR-18a (miR-18a). Overexpression of EBV-miR-BART10-5p and hsa-miR-18a strongly promotes angiogenesis in vitro and in vivo by regulating the expression of VEGF and HIF1-α in a Spry3-dependent manner. In vitro or in vivo treatment with iRGD-tagged exosomes containing antagomiR-BART10-5p and antagomiR-18a preferentially suppressed the angiogenesis and growth of NPC. Our findings first highlight the role of EBV-miR-BART10-5p and oncogenic hsa-miR-18a in NPC angiogenesis and also shed new insights into the clinical intervention and therapeutic strategies for nasopharyngeal carcinoma and other virus-associated tumors.

Drug repositioning in head and neck squamous cell carcinoma: An integrated pathway analysis based on connectivity map and differential gene expression

The severe damage to health and social burden caused by head and neck squamous cell carcinoma (HNSCC) generated an urgent need to develop novel anti-cancer therapy. Currently, drug repositioning has risen in responses to the proper time as an efficient approach to invention of new anti-cancer therapies. In the present study, we aimed to screen candidate drugs for HNSCC by integrating HNSCC-related pathways from differentially expressed genes (DEGs) and drug-affected pathways from connectivity map (CMAP). We also endeavored to unveil the molecular mechanism of HNSCC through creating drug-target network and protein-to-protein (PPI) network of component DEGs in key overlapping pathways. As a result, a total of 401 DEGs were obtained from TCGA and GTEx mRNA-seq data. Taking the intersection part of 27 HNSCC-related Kyoto Encyclopedia of Genes and Genomes pathways and 33 drug-affected pathways, we retained 22 candidate drugs corresponding to two key pathways (cell cycle and p53 signaling pathways) of the five overlapping pathways. Two of the hub genes (PCNA and CCND1) identified from the PPI network of component DEGs in cell cycle and p53 signaling pathways were defined as the critical targets of candidate drugs with increased protein expression in HNSCC tissues, which was reported by the human protein atlas (HPA) database and cBioPortal. Finally, we validated via molecular docking analysis that two drugs with unknown effects in HNSCC: MG-262 and bepridil might perturb the development of HNSCC through targeting PCNA. These candidate drugs possessed broad application prospect as medication for HNSCC.

Effects of peritumoral bevacizumab injection against oral squamous cell carcinoma in a nude mouse xenograft model: A preliminary study

Angiogenesis serves a crucial role in tumor growth. Vascular endothelial growth factor (VEGF) is a potent regulator of tumor angiogenesis and is highly expressed in oral squamous cell carcinoma (OSCC). Bevacizumab, which binds to VEGF-A, inhibits the biological activity of VEGF and is clinically administered by intravenous injection. As intravenous chemotherapy intensifies the side effects experienced by OSCC patients, an alternative treatment option is desirable, particularly for older patients with OSCC who present with systemic disease complications. Generally, local injections of antitumor agents enhance tumoricidal activity and decrease side effects. However, the antitumor effects of peritumoral bevacizumab injections in OSCC are not fully understood. Therefore, the present study examined the effects of peritumoral bevacizumab injections in an experimental nude mouse model of OSCC through immunohistochemical staining for cluster of differentiation (CD)31 and α-smooth muscle actin (α-SMA) and apoptosis assays. It was identified that peritumoral injections of bevacizumab significantly inhibited tumor growth in OSCC xenografts compared with peritumoral saline injections or no treatment (controls), and it was also revealed that treatment with bevacizumab significantly reduced CD31- and α-SMA-positive microvessel density (P<0.01) and increased level of tumor cell apoptosis (P<0.01) compared with the controls. In conclusion, these results collectively support the experimental basis for the clinical development of peritumoral bevacizumab injections for the treatment of OSCC.

Selenium targets resistance biomarkers enhancing efficacy while reducing toxicity of anti-cancer drugs: preclinical and clinical development

Selenium (Se)-containing molecules exert antioxidant properties and modulate targets associated with tumor growth, metastasis, angiogenesis, and drug resistance. Prevention clinical trials with low-dose supplementation of different types of Se molecules have yielded conflicting results. Utilizing several xenograft models, we earlier reported that the enhanced antitumor activity of various chemotherapeutic agents by selenomethione and Se-methylselenocysteine in several human tumor xenografts is highly dose- and schedule-dependent. Further, Se pretreament offered selective protection of normal tissues from drug-induced toxicity, thereby allowing higher dosing than maximum tolerated doses. These enhanced therapeutic effects were associated with inhibition of hypoxia-inducible factor 1- and 2-alpha (HIF1α, HIF2α) protein, nuclear factor (erythyroid-derived 2)-like 2 (Nrf2) and pair-related homeobox-1 (Prx1) transcription factors, downregulation of oncogenic- and upregulation of tumor suppressor miRNAs. This review provides: 1) a brief update of clinical prevention trials with Se; 2) advances in the use of specific types, doses, and schedules of Se that selectively modulate antitumor activity and toxicity of anti-cancer drugs; 3) identification of targets selectively modulated by Se; 4) plasma and tumor tissue Se levels achieved after oral administration of Se in xenograft models and cancer patients; 5) development of a phase 1 clinical trial with escalating doses of orally administered selenomethionine in sequential combination with axitinib to patients with advanced clear cell renal cell carcinoma; and 6) clinical prospects for future therapeutic use of Se in combination with anticancer drugs.

The feasibility of 18F-AlF-NOTA-PRGD2 PET/CT for monitoring early response of Endostar antiangiogenic therapy in human nasopharyngeal carcinoma xenograft model compared with 18F-FDG

Purpose

Radiolabeled arginine-glycine-aspartic acid (RGD) peptides have been developed for PET imaging of integrin avβ3 in the tumor vasculature, leading to great potential for noninvasively evaluating tumor angiogenesis and monitoring antiangiogenic treatment. The aim of this study was to investigate a novel one-step labeled integrin-targeted tracer, ¹⁸F-AlF-NOTA-PRGD2, for PET/CT for detecting tumor angiogenesis and monitoring the early therapeutic efficacy of antiangiogenic agent Endostar in human nasopharyngeal carcinoma (NPC) xenograft model.

Experimental design and results

Mice bearing NPC underwent ¹⁸F-AlF-NOTA-PRGD2 PET/CT at baseline and after 2, 4, 7, and 14 days of consecutive treatment with Endostar or PBS, compared with ¹⁸F-FDG PET/CT. Tumors were harvested at all imaging time points for histopathological analysis with H & E and microvessel density (MVD) and integrin avβ3 immunostaining. The maximum percent injected dose per gram of body weight (%ID/gmax) tumor uptake of ¹⁸F-AlF-NOTA-PRGD2 PET/CT was significantly lower than that in the control group starting from day 2 (p < 0.01), much earlier and more accurately than that of ¹⁸F-FDG PET/CT. Moreover, a moderate linear correlation was observed between tumor MVD and the corresponding tumor uptake of ¹⁸F-AlF-NOTA-PRGD2 PET/CT (r = 0.853, p < 0.01).

Conclusions

¹⁸F-AlF-NOTA-PRGD2 PET/CT can be used for in vivo angiogenesis imaging and monitoring early response to Endostar antiangiogenic treatment in NPC xenograft model, favoring its potential clinical translation.

Tumor rim cells: From resistance to vascular targeting agents to complete tumor ablation

Current vascular targeting strategies pursue two main goals: anti-angiogenesis agents aim to halt sprouting and the formation of new blood vessels, while vascular disrupting agents along with coaguligands seek to compromise blood circulation in the vessels. The ultimate goal of such therapies is to deprive tumor cells out of oxygen and nutrients long enough to succumb cancer cells to death. Most of vascular targeting agents presented promising therapeutic potential, but the final goal which is cure is rarely achieved. Nevertheless, in both preclinical and clinical settings, tumors tend to grow back, featuring a highly invasive, metastatic, and extremely resistant form. This review highlights the critical significance of tumor rim cells as the main factor, determining therapy success with vascular targeting agents. We present an overview of different single and combination treatments with vascular targeting agents that enable efficient targeting of tumor rim cells and long-lasting tumor cure. Understanding the nature of tumor rim cells, how they establish, how they manage to survive of vascular targeting agents, and how they contribute in tumor refractoriness, may open new avenues to the development of beneficial strategies, capable to eliminate residual rim cells, and enable tumor ablation once and forever.

Noninvasive monitoring of early antiangiogenic therapy response in human nasopharyngeal carcinoma xenograft model using MRI with RGD-conjugated ultrasmall superparamagnetic iron oxide nanoparticles

Purpose

Arginine-glycine-aspartic acid (RGD)-based nanoprobes allow specific imaging of integrin αvβ3, a protein overexpressed during angiogenesis. Therefore, this study applied a novel RGD-coupled, polyacrylic acid (PAA)-coated ultrasmall superparamagnetic iron oxide (USPIO) (referred to as RGD-PAA-USPIO) in order to detect tumor angiogenesis and assess the early response to antiangiogenic treatment in human nasopharyngeal carcinoma (NPC) xenograft model by magnetic resonance imaging (MRI).

Materials and methods

The binding specificity of RGD-PAA-USPIO with human umbilical vein endothelial cells (HUVECs) was confirmed by Prussian blue staining and transmission electron microscopy in vitro. The tumor targeting of RGD-PAA-USPIO was evaluated in the NPC xenograft model. Later, mice bearing NPC underwent MRI at baseline and after 4 and 14 days of consecutive treatment with Endostar or phosphate-buffered saline (n=10 per group).

Results

The specific uptake of the RGD-PAA-USPIO nanoparticles was mainly dependent on the interaction between RGD and integrin αvβ3 of HUVECs. The tumor targeting of RGD-PAA-USPIO was observed in the NPC xenograft model. Moreover, the T2 relaxation time of mice in the Endostar-treated group decreased significantly compared with those in the control group both on days 4 and 14, consistent with the immunofluorescence results of CD31 and CD61 (P<0.05).

Conclusion

This study demonstrated that the magnetic resonance molecular nanoprobes, RGD-PAA-USPIOs, allow noninvasive in vivo imaging of tumor angiogenesis and assessment of the early response to antiangiogenic treatment in NPC xenograft model, favoring its potential clinical translation.

Phase II randomized trial of radiation therapy, cetuximab, and pemetrexed with or without bevacizumab in patients with locally advanced head and neck cancer

BACKGROUND

We previously reported the safety of concurrent cetuximab, an antibody against epidermal growth factor receptor (EGFR), pemetrexed, and radiation therapy (RT) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN). In this non-comparative phase II randomized trial, we evaluated this non-platinum combination with or without bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF).

PATIENTS AND METHODS

Patients with previously untreated stage III-IVB SCCHN were randomized to receive: conventionally fractionated radiation (70 Gy), concurrent cetuximab, and concurrent pemetrexed (arm A); or the identical regimen plus concurrent bevacizumab followed by bevacizumab maintenance for 24 weeks (arm B). The primary end point was 2-year progression-free survival (PFS), with each arm compared with historical control. Exploratory analyses included the relationship of established prognostic factors to PFS and quality of life (QoL).

RESULTS

Seventy-eight patients were randomized: 66 oropharynx (42 HPV-positive, 15 HPV-negative, 9 unknown) and 12 larynx; 38 (49%) had heavy tobacco exposure. Two-year PFS was 79% [90% confidence interval (CI) 0.69-0.92; P < 0.0001] for arm A and 75% (90% CI 0.64-0.88; P < 0.0001) for arm B, both higher than historical control. No differences in PFS were observed for stage, tobacco history, HPV status, or type of center (community versus academic). A significantly increased rate of hemorrhage occurred in arm B. SCCHN-specific QoL declined acutely, with marked improvement but residual symptom burden 1 year post-treatment.

CONCLUSIONS

RT with a concurrent non-platinum regimen of cetuximab and pemetrexed is feasible in academic and community settings, demonstrating expected toxicities and promising efficacy. Adding bevacizumab increased toxicity without apparent improvement in efficacy, countering the hypothesis that dual EGFR-VEGF targeting would overcome radiation resistance, and enhance clinical benefit. Further development of cetuximab, pemetrexed, and RT will require additional prospective study in defined, high-risk populations where treatment intensification is justified.

The Proton-Sensing G-Protein Coupled Receptor GPR4 Promotes Angiogenesis in Head and Neck Cancer

Squamous cell carcinoma of the head and neck (SCCHN) is an aggressive disease with poor survival and is the sixth most common cancer worldwide. Gastroesophageal reflux is a common event in SCCHN patients. GPR4 is a proton-sensing G-protein coupled receptor, which can be activated by acidosis. The objective of this study was to explore the role of GPR4 in acid exposure and tumor angiogenesis in SCCHN. In this study, we confirmed that overexpressing GPR4 in SCCHN cells could increase the expression and secretion of IL6, IL8 and VEGFA at pH 5.9. This effect could be inhibited by SB203580 (a p38 inhibitor). Western blot analysis indicated that phosphorylation of p38 increased in GPR4 infected cells at pH 5.9, which could be inhibited by SB203580. In tube formation assay, HMEC-1 cells were incubated with conditioned medium (CM, pH 5.9, 6.5, 7.4) derived from control and GPR4 infected SCCHN cells. Tube length was significantly increased in HMEC-1 cells incubated with CM from GPR4 infected cells compared with control cells at pH5.9, which indicated the pro-angiogenic effect of GPR4 in acidic pH. The neutralizing antibodies of IL6, IL8 and VEGFA could inhibit tube formation of HMEC-1 cells. In vivo, the effect of GPR4 on angiogenesis was investigated with the chick chorioallantoic membrane (CAM) model. Control and GPR4 infected SCCHN cells were seeded onto the upper CAM surface (n = 5 in each group) and 5 μL DMEM/F12 (pH 5.9, 6.5, 7.4) was added to the surface of the cell every 24 h. Four days later, the upper CAM were harvested and the ratio of the vascular area to the CAM area was quantified using Image-Pro Plus 6.0 software. GPR4 infected cells could recruit more vascular than control cells at pH5.9. In conclusion, we suggested that GPR4 induces angiogenesis via GPR4-induced p38-mediated IL6, IL8 and VEGFA secretion at acidic extracellular pH in SCCHN.

Wogonoside inhibits angiogenesis in breast cancer via suppressing Wnt/β-catenin pathway

Wogonoside, a main flavonoid component derived from the root of Scutellaria baicalensis Georgi, has been reported to have anti-angiogenesis and anti-leukemia activities. However, whether it can inhibit tumor angiogenesis is unclear. In this study, we investigate the inhibitory effect of wogonoside on angiogenesis in breast cancer and its underlying mechanisms. ELISA assay shows that wogonoside (25, 50, and 100 µM) decreases the secretion of VEGF in MCF-7 cells by 30.0%, 35.4%, and 40.1%, respectively. We find it inhibits angiogenesis induced by the conditioned media from MCF-7 cells in vitro and in vivo by migration, tube formation, rat aortic ring, and chicken chorioallantoic membrane (CAM) assay. Meanwhile, wogonoside can inhibit the growth and angiogenesis of MCF-7 cells xenografts in nude mice. The reduction of tumor weight can be found both in wogonoside (80 mg/kg) and bevacizumab (20 mg/kg) treated group, and the tumor inhibition rate is 42.1% and 48.7%, respectively. In addition, mechanistic studies demonstrate that wogonoside suppresses the activation of Wnt/β-catenin pathway in MCF-7 cells. Wogonoside (100 µM) decreases the intracellular level of Wnt3a, increases the expression of GSK-3β, AXIN, and promotes the phosphorylation of β-catenin for proteasome degradation significantly. Furthermore, the nuclear accumulation of β-catenin and the DNA-binding activity of β-catenin/TCF/Lef complex are inhibited by 49.2% and 28.7%, respectively, when treated with 100 µM wogonoside. Taken together, our findings demonstrate that wogonoside is a potential inhibitor of tumor angiogenesis and can be developed as a therapeutic agent for breast cancer. © 2015 Wiley Periodicals, Inc.

Bevacizumab might potentiate the chemotherapeutic effect in breast cancer patients with leptomeningeal carcinomatosis

BACKGROUND/PURPOSE

Patients with leptomeningeal carcinomatosis (LC) from breast cancer is generally resistant to systemic chemotherapy. Bevacizumab may increase intratumor concentration of the chemotherapeutic agents through vascular normalization, although the overall clinical benefit of bevacizumab for metastatic breast cancer is under debate.

METHODS

Successful treatment of two breast cancer patients who developed LC after whole brain irradiation treatment for the brain metastases is reported here. Both patients have refractory disease to taxane and anthracycline, and both of them have disease progression under intrathecal methotrexate treatment for LC.

RESULTS

The two patients received systemic chemotherapy with bevacizumab (7.5 mg/kg infusion on Day 1), cisplatin (80 mg/m(2) infusion for 24 hours on Day 2), and etoposide (80 mg/m(2) infusion for 2 hours on Days 2-4) at 21-28 day intervals. Both patients achieved best response of negative cerebral spinal fluid cytology study and dramatic improvement of neurologic deficit after treatment. Their overall survival after development of LC was 8 months and 7.5 months respectively.

CONCLUSION

Bevacizumab plus etoposide and cisplatin might be a new option for breast cancer patients with LC. Further prospective study is warranted.

Interleukin-8 as a modulator of response to bevacizumab in preclinical models of head and neck squamous cell carcinoma

OBJECTIVES

Bevacizumab, a monoclonal antibody to VEGF-A, is under active clinical evaluation in head and neck squamous cell carcinoma (HNSCC) and appears to be a promising therapy in at least a subset of patients. However, there are no reliable predictive biomarkers to identify those patients most likely to benefit. In this study, we assessed the efficacy of bevacizumab in HNSCC xenograft models to characterize escape mechanisms underlying intrinsic resistance and identify potential biomarkers of drug response.

MATERIALS AND METHODS

We evaluated the angiogenic profile of HNSCC cells from sensitive and resistant cell lines using antibody array. We further examined the role of interleukin-8 (IL-8) in contributing to resistance both in vitro and in vivo, using a loss- and gain-of-function approach.

RESULTS

Angiogenic profiling indicated that resistant cells expressed higher levels of proangiogenic factors including IL-8, interleukin-1α (IL-1α), vascular endothelial growth factor (VEGF), fibroblast growth factor-a (FGF-a), and tumor necrosis factor-α (TNF-α). IL-8 was the most differentially expressed protein. IL-8 signaling compensated for VEGF inhibition in endothelial cells. Downregulation of IL-8 resulted in sensitization of resistant tumors to bevacizumab by disrupting angiogenesis and enhancing endothelial cell apoptosis. Overexpression of IL-8 in sensitive tumors conferred resistance to bevacizumab. Serum analysis of HNSCC patients treated with a bevacizumab-containing regime revealed high baseline IL-8 levels in a subset of patients refractory to treatment but not in responders.

CONCLUSIONS

These results implicate IL-8 in mediating intrinsic resistance to bevacizumab in HNSCC. Hence, co-targeting of VEGF and IL-8 may help overcome resistance and enhance therapeutic efficacy.

Using intravital microscopy to observe bevacizumab-mediated anti-angiogenesis in human head and neck squamous cell carcinoma xenografts

CONCLUSION

The study showed the value of using intravital microscopy (IVM) analysis for the study of neoangiogenesis. It demonstrated that the model and the analytical methodology could be used to evaluate in detail the effects of treatment strategies for solid tumours.

OBJECTIVES

Neoangiogenesis is a key component of tumour progression, invasion and metastasis. In clinical trials monoclonal antibodies specific for vascular endothelial growth factor - VEGF (bevacizumab) - have been shown to significantly affect tumour progression when given in combination with standard chemotherapy, and also to improve the overall survival of patients. For squamous cell carcinoma of the head and neck (HNSCC), we still await definitive evidence of the effect of such treatment. The present study was designed to investigate the anti-angiogenesis effect of beviacizumab in green fluorescent protein (GFP)-labelled HNSCC xenografts using IVM technology.

METHODS

We performed IVM and used image analysis for quantification of angiogenesis and of effects of bevacizumab on cell viability, combined with histochemical and immunohistochemical analysis to standardize the digital analysis of changes in tumour vascularization and cell viability.

RESULTS

We found significant effects of bevacizumab on angiogenesis and cancer cell survival in HNSCC. Repeated injections of bevacizumab were found to provide the greatest effects.

The role of antiangiogenic agents in the treatment of head and neck cancer

Despite progress in the treatment of locally advanced head and neck squamous cell cancer (HNSCC), the prognosis remains dismal and 5-year survival does not exceed 40%. In metastatic and recurrent disease, in spite of the introduction of cetuximab in combination with platinum and fluorouracil, the median overall survival rate remains lower than 11 months. There are many possible reasons for these disappointing results including acquired drug resistance and tumor hypoxia. Angiogenesis plays an important role in HNSCC development and proliferation. Promising preclinical results with antiangiogenic therapies have engendered a number of clinical trials, but so far there have not been any conclusive results on the value of such treatments. This paper aims to review the role of angiogenesis in head and neck cancer and to suggest future perspectives.

Biologic therapy in head and neck cancer: a road with hurdles

The epidermal growth factor receptor (EGFR) is overexpressed in the vast majority of cases of squamous cell carcinoma of the head and neck (SCCHN). A high EGFR expression is associated with an unfavorable prognosis. Cetuximab is a chimeric human/murine IgG1 antibody which binds with high affinity to the EGFR. It is the only targeted agent which got approval for the treatment of SCCHN from the regulatory agencies of Europe and the United States, both in locoregionally advanced disease, in association with radiation, and in recurrent/metastatic disease. The outcome of trials involving other EGFR-directed monoclonal antibodies, that is, zalutumumab and panitumumab, was consistent with the results with cetuximab. However these trials failed to meet their primary endpoint. The results with EGFR-directed tyrosine kinase inhibitors have been disappointing. Other potential targets for treatment in SCCHN include the entire ErbB family, the vascular endothelial growth factor (VEGF) and its receptor (VEGFR), the insulin-like growth factor 1 receptor (IGF-1R), the insulin receptor (IR), histone deacetylases (HDAC), the mammalian target of rapamycin (mTOR), the platelet-derived growth factor receptor (PDGFR), heat-shock protein 90 (HSP90), nuclear factor-kappa B (NF-κB), aurora A or B, and phosphatidylinositol 3-kinase (PIK3CA).

Lipid-based nanoformulation of irinotecan: dual mechanism of action allows for combination chemo/angiogenic therapy

A number of studies have outlined the antiangiogenic effects of cytotoxic agents when administered frequently at low doses. These studies suggest that the effect of the cytotoxic agent is on the vasculature within the tumor and it is assumed that there is little or negligible cytotoxicity. Liposomal drug delivery systems have the ability to provide a dual mechanism of activity where tumor accumulation can deliver high local concentrations of the drug at the site of action with concomitant slow release of the drug from carriers in the blood compartment that results in antivascular effects, similar to that achieved when dosing frequently at low levels. Although this dual mechanism of activity may be linked to other lipid nanoparticle formulations of anticancer drugs, this article summarizes the evidence supporting direct (cytotoxic) and indirect (antivascular) actions of a liposomal formulation of irinotecan.