Evaluating antiangiogenesis agents in the clinic: the Eastern Cooperative Oncology Group Portfolio of Clinical Trials

A rectovaginal fistula after treatment with bevacizumab. A dangerous side effect needing emergency treatment

Despite its effectiveness in the treatment of malignant tumors, bevacizumab is associated with a variety of side effects such as the formation of fistulas (i.e., tracheoesophageal, colovaginal, or rectovaginal). It is important to recognize immediately the emergence of this entity in order to discontinue bevacizumab permanently and treat the fistula.

Use of Vacuum-assisted closure in management of open abdominal wound with multiple enterocutaneous fistulae during chemotherapy: A case report

INTRODUCTION

Vacuum-assisted closure (VAC) is useful for treating complex wounds because it promotes granulation. In the present report, a successful case of VAC used for an open abdominal wound with enterocutaneous fistulae after multiple intestinal perforations during chemotherapy is described.

PRESENTATION OF CASE

A 73-year-old man was admitted to our hospital with severe abdominal pain. He underwent surgical resection for ascending colon cancer 4 years ago and was administered chemotherapy with bevacizumab for recurrence. Physical examination and computed tomography revealed perforation of the intestine, and an emergency operation was performed. Following this procedure, other intestinal perforations occurred, resulting in an open abdominal wound at postoperative day (POD) 10. To isolate enteric contents and promote granulation, VAC was applied to the abdominal wound with enterocutaneous fistulae. Oral intake started at POD 21 and the wound size became smaller. Further, an ostomy bag was directly attached to the most oral perforation site. The patient recovered from life-threatening events without severe infection and was transferred to another hospital close to his home at POD 180.

DISCUSSION

Gastrointestinal perforation is known to be one of the fatal adverse events of bevacizumab. In this case four gastrointestinal perforations were observed. Isolation of enteric contents is important to heal the wound and VAC is an effective therapy for the management of open abdominal wounds even with enterocutaneous fistulae.

CONCLUSION

Innovative VAC use for the management of open abdominal wounds can improve the nutritional status and overall wound healing of the patient.

RLIP76 regulates HIF-1 activity, VEGF expression and secretion in tumor cells, and secretome transactivation of endothelial cells

This study was undertaken to reveal the mechanisms by which RLIP76 regulates endothelial cell angiogenic responses. RLIP76 is an effector of the angiogenic modulator, R-Ras. RLIP76 is overexpressed in many tumors, required for tumor angiogenesis, and blockade of RLIP76 results in tumor regression in multiple models. We report here that RLIP76 was required for expression and secretion of vascular endothelial growth factor (VEGF) in carcinoma and melanoma cells. Conditioned medium derived from RLIP76-depleted tumor cells, but not control knockdown cells, could not stimulate proliferation, migration, or Matrigel cord formation in endothelial cell cultures, which indicates that RLIP76 regulates angiogenic components of the tumor cell secretome. Recombinant VEGF added to conditioned medium from RLIP76-knockdown tumor cells restored these endothelial cell functions. Transcriptional activity of hypoxia-inducible factor 1 (HIF-1), which drives VEGF expression, was blocked in RLIP76-depleted tumor cells. RLIP76 was required for PI3-kinase activation, known to regulate HIF-1, in these cells. However, HIF-1α expression and nuclear localization were unaffected by RLIP76 knockdown, which suggests that RLIP76 regulates HIF-1 at the functional level. Thus, RLIP76 regulates tumor cell transactivation of endothelial cells via control of VEGF expression and secretion, providing a new important link in the mechanism of tumor cell induction of angiogenesis.

Updated and new perspectives on diagnosis, prognosis, and therapy of malignant pheochromocytoma/paraganglioma

Malignant pheochromocytomas/paragangliomas are rare tumors with a poor prognosis. Malignancy is diagnosed by the development of metastases as evidenced by recurrences in sites normally devoid of chromaffin tissue. Histopathological, biochemical, molecular and genetic markers offer only information on potential risk of metastatic spread. Large size, extraadrenal location, dopamine secretion, SDHB mutations, a PASS score higher than 6, a high Ki-67 index are indexes for potential malignancy. Metastases can be present at first diagnosis or occur years after primary surgery. Measurement of plasma and/or urinary metanephrine, normetanephrine and metoxytyramine are recommended for biochemical diagnosis. Anatomical and functional imaging using different radionuclides are necessary for localization of tumor and metastases. Metastatic pheochromocytomas/paragangliomas is incurable. When possible, surgical debulking of primary tumor is recommended as well as surgical or radiosurgical removal of metastases. I-131-MIBG radiotherapy is the treatment of choice although results are limited. Chemotherapy is reserved to more advanced disease stages. Recent genetic studies have highlighted the main pathways involved in pheochromocytomas/paragangliomas pathogenesis thus suggesting the use of targeted therapy which, nevertheless, has still to be validated. Large cooperative studies on tissue specimens and clinical trials in large cohorts of patients are necessary to achieve better therapeutic tools and improve patient prognosis.

Changing paradigms in the treatment of malignant pheochromocytoma

BACKGROUND

Pheochromocytomas and paragangliomas are intra- and extra-adrenal neoplasms that are rarely malignant. The treatment of those that are malignant has remained a challenge because little was known about the molecular pathways involved in its malignant transformation. Recently, however, the genetic and molecular changes involved in malignant pheochromocytoma have come to be understood.

METHODS

The authors review the recent literature about the changing treatment options for malignant pheochromocytomas and paragangliomas.

RESULTS

Traditional treatments for malignant pheochromocytoma remain unsuccessful. With the advances made in genomics and proteomics, novel pathways in pheochromocytoma carcinogenesis are becoming the targets of new treatment strategies and show promising results.

CONCLUSIONS

Although several studies and clinical trials show great promise for improving the treatment of pheochromocytomas and paragangliomas, the hope is that future collaborative efforts will allow for prospective clinical trials using an evidenced-based approach.

Role of endoglin and VEGF family expression in colorectal cancer prognosis and anti-angiogenic therapies

Colorectal cancer (CRC) is one of the cancer models and most of the carcinogenic steps are presently well understood. Therefore, successful preventive measures are currently used in medical practice. However, CRC is still an important public health problem as it is the third most common cancer and the fourth most frequent cause of cancer death worldwide. Nowadays, pathologic stage is a unique and well-recognized prognostic indicator, however, more accurate indicators of the biologic behavior of CRC are expected to improve the specificity of medical treatment. Angiogenesis plays an important role in the growth and progression of cancer but its role as a prognostic factor is still controversial. Probably the most important clinical implication of tumor angiogenesis is the development of anti-angiogenic therapy. The goal of this review is to critically evaluate the role of angiogenic markers, assessed by either endoglin-related microvessel density or expression of vascular endothelial growth factor family members in the CRC setting and discuss the role of these angiogenic markers in anti-angiogenic therapies.

PG545, a dual heparanase and angiogenesis inhibitor, induces potent anti-tumour and anti-metastatic efficacy in preclinical models

Background:

PG545 is a heparan sulfate (HS) mimetic that inhibits tumour angiogenesis by sequestering angiogenic growth factors in the extracellular matrix (ECM), thus limiting subsequent binding to receptors. Importantly, PG545 also inhibits heparanase, the only endoglycosidase which cleaves HS chains in the ECM. The aim of the study was to assess PG545 in various solid tumour and metastasis models.

Methods:

The anti-angiogenic, anti-tumour and anti-metastatic properties of PG545 were assessed using in vivo angiogenesis, solid tumour and metastasis models. Pharmacokinetic (PK) data were also generated in tumour-bearing mice to gain an understanding of optimal dosing schedules and regimens.

Results:

PG545 was shown to inhibit angiogenesis in vivo and induce anti-tumour or anti-metastatic effects in murine models of breast, prostate, liver, lung, colon, head and neck cancers and melanoma. Enhanced anti-tumour activity was also noted when used in combination with sorafenib in a liver cancer model. PK data revealed that the half-life of PG545 was relatively long, with pharmacologically relevant concentrations of radiolabeled PG545 observed in liver tumours.

Conclusion:

PG545 is a new anti-angiogenic clinical candidate for cancer therapy. The anti-metastatic property of PG545, likely due to the inhibition of heparanase, may prove to be a critical attribute as the compound enters phase I clinical trials.

Vitamin D binding protein-macrophage activating factor inhibits HCC in SCID mice

BACKGROUND

A high incidence of recurrence after treatment is the most serious problem in hepatocellular carcinoma (HCC). Therefore, a new strategy for the treatment of the disease is needed. The aim of the present study was to investigate whether vitamin D binding protein-macrophage activating factor (DBP-maf) is able to inhibit the growth of HCC.

METHODS

The effects of DBP-maf on endothelial cells and macrophage were evaluated by WST-1 assay and phagocytosis assay, respectively. Human HCC cells (HepG2) were implanted into the dorsum of severe combined immunodeficiency (SCID) mice. These mice were divided into control and DBP-maf treatment groups (n = 10/group). The mice in the treatment group received 40 ng/kg/d of DBP-maf for 21 d.

RESULTS

DBP-maf showed anti-proliferative activity against endothelial cells and also activated phagocytosis by macrophages. DBP-maf inhibited the growth of HCC cells (treatment group: 126 ± 18mm(3), untreated group: 1691.5 ± 546.9mm(3), P = 0.0077). Histologic examinations of the tumors revealed the microvessel density was reduced and more macrophage infiltration was demonstrated in the tumor of mice in the treatment group.

CONCLUSION

DBP-maf has at least two novel functions, namely, an anti-angiogenic activity and tumor killing activity through the activation of macrophages. DBP-maf may therefore represent a new strategy for the treatment of HCC.

Angiogenesis in melanoma

The process of angiogenesis is crucial for progression and metastasis of the majority of solid tumors including melanomas. The current review summarizes existing knowledge of the mechanisms of angiogenesis in melanoma, as well as current anti-angiogenic therapeutic strategies and their targets. We focus primarily on the role of key growth factors that are secreted by melanoma cells and known to trigger angiogenic responses, and their receptors as expressed on both endothelial and melanoma cells. Many of these growth factors function in synergy with receptors for extracellular matrix, integrins, and matrix metalloproteinases (MMPs). All of these systems of molecules are activated during major stages of angiogenesis such as endothelial migration, proliferation, and reorganization of surrounding extracellular matrix. The blockade of these molecules and their downstream pathways leads to inhibition of melanoma vascularization. Thus, these classes of molecules are essential for melanoma angiogenesis and, therefore, might serve as promising targets for therapeutic intervention. Many recently developed compounds targeting key pathways in angiogenesis are in their final stages of clinical trials.

Characterization of thalidomide using Raman spectroscopy

Thalidomide is a potent anticancer therapeutic drug whose mechanism of action has not yet been elucidated. In this report, experimental Raman spectroscopy is used to determine and characterize the vibrational frequencies of the drug. These normal modes are then compared to their quantum mechanical counterparts, which have been computed using density functional theory. Upon analysis of the spectra, we found that there was a high level of agreement between the wavenumbers. As such, this spectroscopic technique may be a viable tool for examining the way in which this drug interacts with its target molecules.

Challenges of antiangiogenic cancer therapy: trials and errors, and renewed hope

Angiogenesis inhibition has been proposed as a general strategy to fight cancer. However, in spite of the promising preclinical results, a first generation of antiangiogenic compounds yielded poor results in clinical trials. Conceptual errors and mistakes in the design of trials and in the definition of clinical end-points could account for these negative results. In this context of discouraging results, a second generation of antiangiogenic therapies is showing positive results in phases II and III trials at the beginning of the twenty-first century. In fact, several combined treatments with conventional chemotherapy and antiangiogenic compounds have been recently approved. The discovery and pharmacological development of future generations of angiogenesis inhibitors will benefit from further advances in the understanding of the mechanisms involved in human angiogenesis. New styles of trials are necessary, to avoid missing potential therapeutic effects. Different clinical end-points, new surrogate biomarkers and methods of imaging will be helpful in this process. Real efficacy in clinical trials may come with the combined use of antiangiogenic agents with conventional chemotherapy or radiotherapy, and combinations of several antiangiogenic compounds with different mechanisms of action. Finally, the existing antiangiogenic strategies should include other approaches such as vascular targeting or angioprevention.

Pleiotrophin is highly expressed by myeloma cells and promotes myeloma tumor growth

Pleiotrophin (PTN) is an important developmental cytokine that is highly expressed during embryogenesis but shows very limited expression in adult tissues, where it is largely restricted to the brain. High PTN serum levels are associated with a variety of solid tumors. We recently showed that patients with multiple myeloma (MM) also have elevated serum levels of this protein and the amount of PTN correlated with the patients' disease status and response to treatment. In this study, we demonstrate that MM cell lines and the malignant cells from MM patients' bone marrow produced PTN and secreted PTN protein into the supernatants during short-term culture. Moreover, Ptn gene expression correlated with the patients' disease status. Inhibition of PTN with a polyclonal anti-PTN antibody reduced growth and enhanced apoptosis of MM cell lines and freshly isolated bone marrow tumor cells from MM patients in vitro. Importantly, this antibody also markedly suppressed the growth of MM in vivo using a severe combined immunodeficiency (SCID)-hu murine model. This represents the first study showing the importance of PTN in the growth of any hematological disorder. Because the expression of this protein is very limited in normal adult tissues, PTN may represent a new target for the treatment of MM.

EGFR targeting therapies: monoclonal antibodies versus tyrosine kinase inhibitors. Similarities and differences

Current development of targeted therapy in oncology is particularly active and concerns principally two types of agents which are monoclonal antibodies (Mabs) and tyrosine kinase inhibitors (TKIs). Epidermal growth factor receptor (EGFR) signaling pathways play a key role in the regulation of cell proliferation, survival and differentiation. Consequently, EGFR is one of the most-studied ligand-receptor systems and specific EGFR inhibition approaches are currently among the most promising and the most advanced in the clinical setting. Cetuximab (Erbitux), belonging to the Mabs family, gefitinib (Iressa) and erlotinib (Tarceva), belonging to the TKIs family, are among the most advanced anti-EGFR drugs at the clinical level. The aim of this review article is to compare at both experimental and clinical levels the key points which govern the activity of these two types of targeting agents.

Cellules dendritiques et gliomes : un espoir en immunothérapie ?

Immunotherapy has been explored for several decades to try to improve the prognosis of gliomas, but until recently no therapeutic benefit has been achieved. The discovery of dendritic cells, the most potent professional antigen presenting cells to initiate specific immune response, and the possibility of producing them ex vivo gave rise to new protocols of active immunotherapy. In oncology, promising experimental and clinical therapeutic results were obtained using these dendritic cells loaded with tumor antigen. Patients bearing gliomas have deficit antigen presentation making this approach rational. In several experimental glioma models, independent research teams have showed specific antitumor responses using these dendritic cells. Phase I/II clinical trials have demonstrated the feasibility and the tolerance of this immunotherapeutic approach. In neuro-oncology, the efficiency of such an approach remains to be established, similarly in oncology where positive phase III studies are missing. Nevertheless, dendritic cells comprise a complex network which is only partially understood and capable of generating either immunotolerance or immune response. Numerous parameters remain to be explored before any definitive conclusion about their utility as an anticancer weapon can be drawn. It seems however logical that immunotherapy with dendritic cells could prevent or delay tumor recurrence in patients with minor active disease. A review on glioma and dendritic cells is presented.

Oncolytic HSV armed with platelet factor 4, an antiangiogenic agent, shows enhanced efficacy

Oncolytic herpes simplex viruses (HSV) have emerged as a promising platform for cancer therapy. However, efficacy as single agents has thus far been unsatisfactory. Tumor vasculature is critical in supporting tumor growth, but successful antiangiogenic approaches often require maintaining constant levels of antiangiogenic products. We hypothesized that oncolytic HSV has the potential to destroy tumor vasculature and that this effect can be enhanced by combination with antiangiogenic gene transfer. We examined the strategy of arming oncolytic HSV with an antiangiogenic transgene, platelet factor 4 (PF4). The PF4 transgene was inserted into oncolytic HSV G47Delta utilizing a bacterial artificial chromosome construction system. Whereas bG47Delta-empty showed robust cell killing and migration inhibition of proliferating endothelial cells (HUVEC and Py-4-1), the effect was further enhanced by PF4 expression. Importantly, enhanced potency did not impede viral replication. In vivo, bG47Delta-PF4 was more efficacious than its nonexpressing parent bG47Delta-empty at inhibiting tumor growth and angiogenesis in both human U87 glioma and mouse 37-3-18-4 malignant peripheral nerve sheath tumor models. Enhancing the antiangiogenic properties of oncolytic HSV through the expression of antiangiogenic factors such as PF4 is a powerful new strategy that targets both the tumor cells and tumor vasculature.

Drugs to suppress cough

Cough is an important defensive reflex of the airway and also a common symptom of respiratory disease. Cough after common respiratory virus infection is transient but is more persistent when associated with conditions such as asthma, rhinosinusitis, gastro-oesophageal reflux, chronic obstructive pulmonary disease and lung cancer. Persistent cough may be due to peripheral and/or central sensitisation of cough reflexes initiated by cough receptors, rapidly adapting receptors or nociceptors. Treatment directed at associated conditions such as asthma (with anti-inflammatories) and gastro-oesophageal reflux (with proton-pump inhibitors) improve cough. There remains a need to use drugs that suppress the neural activity of cough (termed nonspecific), as treatments directed at the clinical cause(s) of the underlying cough (termed specific) may not be effective. The most effective indirect antitussives are opioids such as morphine, codeine or pholcodeine, but they produce side effects such as drowsiness, nausea, constipation and physical dependence. Opioids such as kappa- and delta-receptor agonists, non-opioids such as nociceptin, neurokinin and bradykinin receptor antagonists, cannabinoids, vanilloid receptor-1 antagonists, blockers of Na+-dependent channels, and large conductance Ca2+-dependent K+-channel activators of afferent nerves may represent novel antitussives.

Antiprotease therapy in cancer: hot or not?

The activity of a set of peptidases (proteases) involved in cancer progression is collectively known as the cancer 'degradome'. Invasion and metastasis were initially considered as late events in cancer development and the processes in which proteases were involved. However, recent studies indicate that invasion and metastasis are not late events, but can occur during early stages as well. Moreover, other processes occurring in various stages of cancer progression are also protease-dependent, such as (upregulation of) cell proliferation, (downregulation of) apoptosis, involvement of white blood cells, angiogenesis and induction of multi-drug resistance. Proteolytic activity in tumours is regulated in a complex manner, as both genetically unstable cancer cells and stable stromal cells, such as fibroblasts, endothelial cells and inflammatory cells, are involved. In vitro studies and studies using animal models have clearly shown protease dependency of many processes in carcinogenesis. However, clinical trials using protease inhibitors have thus far been unsuccessful except for a few applications of matrix metalloprotease (MMP) inhibitors when used in combination with cytostatic anticancer agents and/or in the early stages of cancer. Antithrombotics, such as low-molecular-weight heparin and warfarin, were also successful in clinical trials, probably by interfering with proteases of the coagulation cascade. The two-way association between cancer and thrombosis has long been recognised in the clinic. The poor outcome of other clinical trials of protease inhibitors is probably due to the late stages of cancer of the patient populations included, and the limited understanding of the complex regulation and effects of the activity of the various proteases in tumours depending on, among others, tumour type and stage, interactions between the cancer cells, other cells and the extracellular matrix in tumours. Therefore, a better fundamental understanding of the proteolytic complexity in tumours is essential before clinical trials can be rationally designed. At present, antithrombotics, the urokinase-type plasminogen activator system, the membrane-bound membrane-type 1-MMP, cathepsin L and the proteasome seem the most promising candidates as targets for anticancer strategies in early stages of cancer in combination with cytotoxic drugs. Moreover, metronomic therapy is an attractive approach using low doses of inhibitors for prolonged periods of time without interruption to specifically target endothelial cells that are involved in angiogenesis.

Matrix metalloproteinases in cancer: comparison of known and novel aspects of their inhibition as a therapeutic approach

Matrix dissolution is a crucial step during tumor progression that converts a premalignant cell to an overtly malignant one. Main players in this step are the various matrix metalloproteinases (MMPs), which differ in substrate specificity and tissue distribution, and thereby also differ in presence and function during various stages of initial and systemic tumor spread. Accordingly, the inhibition of MMP synthesis and/or activity represents novel potential therapeutic strategies for the treatment of cancer patients. Considerable work has already been carried out on synthetic inhibitors of MMP activity, but with little or even adverse effects in recent clinical studies. The reasons may be inappropriate patient populations in too advanced tumor stages, or inappropriate enzymes as targets for inhibition. Upregulation of endogenous tissue inhibitors of MMP (TIMPs) also provided ambiguous results, since TIMPs possess biologic functions in addition to MMP inhibition, for example, TIMP-2 is a main player in the MMP-2 activation cascade. This may explain, at least in part, the adverse effects of TIMP application/upregulation. Other strategies have been sought in order to overcome these problems. These include the downregulation of MMP transcription by cytokines. However, the effects of cytokines (other than MMP inhibition) may also limit the use of this approach. Finally, empiric evidence for control and modulation of MMP transcription and/or activation by several naturally occurring substances, such as flavonoids, green tea polyphenols and curcumin, represent novel options for the control of MMP activity even in early tumor stages. Additionally, these substances have little or no toxic side effects and good bioavailability, and therefore their continuing analysis provides intriguing insight into tumor pathophysiology and possibly new therapeutic options.

Molecularly targeted therapy for melanoma

Effective therapy for melanoma remains an unmet goal, with most traditional therapies representing inadequate trade-offs among the several goals of specificity, efficacy, and toxicity. Targeted molecular therapeutics are tailored to genetic abnormalities that are associated with tumor progression. Modulation of aberrant signaling pathways in cancer cells has the potential to provide more effective and potentially nontoxic therapy for a broad range of cancers, including melanoma. Among the possible targets in melanoma are the Ras-MAPK and PI3K/AKT signal transduction pathways, the proteasome, histone deacetylases, methyltransferases, and melanoma-induced angiogenesis.

Treatment for multiple bilobar liver metastases of colorectal cancer

BACKGROUND

Recent advances have extended indications for hepatectomy to include multiple bilobar colorectal liver metastases (CLM). Staging systems based on the biological malignancy of primary and metastatic tumors provide appropriate indications for hepatectomy in CLM. However, suitability for resection in patients with complex and extensive hepatic metastases is controversial.

METHODS

A medline search was performed to identify papers reporting the resection for CLM. Techniques, indication, and results were reviewed.

RESULTS

If the anticipated remnant liver volume is small (25-40% of total), suggesting a high risk of postoperative liver failure, portal vein embolization (PVE) is recommended prior to hepatectomy. However, curative resections are not always possible. Specifically in synchronous multiple bilobar CLM, two-stage hepatectomy, comprising bilateral hepatectomy and primary resection with or without PVE, can prevent growth of ipsilateral metastatic nodules in the remnant liver and reduce surgical risk. Several local ablation techniques can complement surgery if hepatic resection alone increases the risk of postoperative liver failure or is not curative. Chemotherapy combined with targeted treatment can suppress recurrence and extend indications for hepatectomy by reducing the size and number of primary irresectable tumors.

CONCLUSION

PVE or staged procedure combining with local ablation or neoadjuvant, downstaging or adjuvant therapies extends indications for hepatectomy to include multiple bilobar CLM. The 5-year survival rate for multiple bilobar CLM treated with alternating hepatectomy and chemotherapy is comparable to the values reported for single and hemilateral CLM.

Therapeutic renaissance of thalidomide in the treatment of haematological malignancies

Very few drugs had a history similar to that of thalidomide (alpha-N-[phthalimido] gluramide). First introduced in the late 1950s in Germany, in 1961 thalidomide was withdrawn due to its teratogenic effects. More than three decades after, it is attracting growing interest because of its reported immunomodulatory and anti-inflammatory properties. The discovery that thalidomide inhibits angiogenesis led to preclinical and clinical trials as an anticancer agent in the treatment of solid tumours and haematological malignancies, as summarized in this review article. More recently, structural analogues of thalidomide have been synthesized in order to explore potential molecular targets of thalidomide, as well as to identify new agents with improved therapeutic efficacy.

Improved therapeutic effectiveness by combining recombinant CXC chemokine ligand 10 with Cisplatin in solid tumors

PURPOSE

CXC chemokine ligand 10 (CXCL10) is a potent inhibitor of angiogenesis. We wonder whether the combination of CXCL10 with cisplatin would improve the therapeutic antitumor efficacy.

EXPERIMENT DESIGN

We evaluated the antitumor activity of the combination therapy in the immunocompetent C57BL/6 and BALB/c mice bearing LL/2 Lewis lung cancer and CT26 colon adenocarcinoma, respectively. Mice were treated with either CXCL10 s.c. at 25 mug per kg per day once daily for 30 days, cisplatin cycled twice (5 mg/kg i.p. on days 14 and 21 after the initiation of CXCL10), or both agents together. Tumor volume and survival time were observed. Antiangiogenesis of CXCL10 in vivo were determined by alginate capsule models and CD31 immunohistochemistry. Histologic analysis and assessment of apoptotic cells were also conducted in tumor tissues.

RESULTS

CXCL10 + cisplatin reduced tumor growth in LL/2 and CT26 tumor model, respectively, more effectively, although cisplatin or CXCL10 individually resulted in suppression of tumor growth and improved survival time of tumor-bearing mice. CXCL10 successfully inhibited angiogenesis as assessed by alginate model and CD31 (P < 0.05). Histologic analysis of tumors exhibited that CXCL10 in combination with cisplatin led to the increased rate of apoptosis, tumor necrosis, and elevated lymphocyte infiltration.

CONCLUSIONS

Our data suggest that the combination of CXCL10, a well-tolerated angiogenesis inhibitor, with cisplatin can enhance the antitumor activity. The present findings may be of importance to the further exploration of the potential application of this combined approach in the treatment of lung and colon carcinoma.

Bevacizumab in combination chemotherapy for colorectal and other cancers

PURPOSE

The pharmacology, pharmacokinetics, pharmacodynamics, clinical efficacy, adverse effects, and dosage and administration of bevacizumab in patients with colorectal and other cancers are reviewed.

SUMMARY

Bevacizumab is a recombinant human monoclonal antibody that inhibits the biological activities of vascular endothelial growth factor (VEGF), a protein involved in the neovascularization of multiple malignant tumors. A single dose of bevacizumab 0.1-10 mg/kg yields a maximum concentration of 2.8-284 microg/mL and shows a dose-response relationship. Pre-clinical and clinical studies have shown that bevacizumab has both cytostatic and cytotoxic effects, resulting in a reduction in tumor growth and increases in median survival time and time to tumor progression. Bevacizumab is available as an intravenous agent and carries FDA-approved labeling for use in the first-line treatment of meta-static colorectal cancer in combination with fluorouracil-based chemotherapy. Bevacizumab 5 mg/kg is infused intravenously over 30-90 minutes every two weeks. No dosage reductions are required for patients with renal or hepatic dysfunction. Bevacizumab has also yielded preliminary evidence of efficacy for breast, non-small-cell lung, pancreatic, prostate, renal, and hepatic cancers, as well as for melanoma and acute myelogenous leukemia. The most frequent adverse effects are nausea, vomiting, headache, epistaxis, anorexia, stomatitis, dyspnea, and constipation.

CONCLUSION

Bevacizumab combined with fluorouracil-based chemotherapy has become the standard of care for the first-line treatment of metastatic colorectal cancer and may prove useful for other tumors as well.

New antiangiogenic strategies for the treatment of proliferative synovitis

Angiogenesis inhibition, which has been extensively studied for the treatment of various malignancies, is beginning to emerge as a new potential therapy for proliferative synovitis, particularly rheumatoid arthritis (RA). The rheumatoid pannus, the site of inflammation and joint destruction in the rheumatoid synovium, relies on the development of new vasculature to sustain its growth. A host of mediators have been shown to induce angiogenesis at the site of the inflamed synovium; these include vascular endothelial growth factor, fibroblast growth factor, integrin alpha(V)beta3, angiopoietin, prosta-glandin E1 and prostaglandin E2, and matrix metalloproteinases. In addition, hypoxia at the site of synovial inflammation contributes to angiogenesis stimulation. Several naturally-occurring inhibitors exist, such angiostatin and endostatin. There are a number of drugs undergoing study in the treatment of proliferative synovitis, which capitalise on the correlation between angiogenesis inhibition and the reduction of signs and symptoms of RA. Paclitaxel and an anti-integrin alpha(V)beta3 antibody, LM-609, are currently in clinical trials. Other drugs that may inhibit angiogenesis in RA include TNP-470 (formerly called AGM-1470), PPI-2458, PTK-787, bevacizumab and thalidomide. Many of these drugs have shown promise for the treatment of oncologic disorders, and are now being evaluated for the treatment of proliferative synovitis.