Clinical Trials of Antiangiogenesis Therapy in Recurrent/Persistent and Metastatic Cervical Cancer.

BACKGROUND: Treatment options for women with metastatic, persistent, or recurrent cervical cancer are limited and thus the disease portends a poor prognosis. It is critical to understand the pathophysiology of cervical cancer to better delineate therapeutic targets. The development of antiangiogenic therapies and their subsequent analysis in rigorous therapeutic trials have redefined current management strategies and is an exciting area of current exploration. RESULTS: Translational trials have furthered the understanding of molecular determinants of angiogenesis. Phase II trials have shown promising trends with developing antiangiogenic therapies. A practice-changing phase III trial has recently been published. Given the potential benefits and different toxicity spectrum compared with standard cytotoxic chemotherapy, antiangiogenic options are under active investigation for this vulnerable patient population. Emerging data are promising for other antiangiogenic-directed therapeutics, as well as cervical cancer molecular biomarkers to guide diagnosis and treatment. CONCLUSION: Antiangiogenic therapies have evolved during the past 20 years and remain an exciting area of current exploration. IMPLICATIONS FOR PRACTICE: Understanding of the angiogenic microenvironment has furthered understanding of tumor biology and management. Antiangiogenic therapies show promise for women with advanced cervical cancer. A review of the evolution of these biologic agents shows them to be an effective and tolerable management strategy for many patients in this vulnerable population, with exciting future potential.

Advanced Chemoembolization by Anti-angiogenic Calcium-Phosphate Ceramic Microspheres Targeting the Vascular Heterogeneity of Cancer Xenografts.

The purpose of the present study was to develop an advanced method of anti-angiogenic chemoembolization to target morphological vascular heterogeneity in tumors and further the therapeutic efficacy of cancer treatment. This new chemoembolization approach was designed using resorbable calcium-phosphate ceramic microspheres (CPMs), in a mixture of three different sizes, which were loaded with an anti-angiogenic agent to target the tumor vasculature in highly angiogenic solid tumors in humans in vivo. The human uterine carcinosarcoma cell line, FU-MMT-3, was used in this study because the tumor is highly aggressive and exhibits a poor response to radiotherapy and chemotherapeutic agents that are in current use. CPMs loaded with TNP-470, an anti-angiogenic agent, were injected into FU-MMT-3 xenografts in nude mice three times per week for 8 weeks. The treatment with TNP-470-loaded CPMs of three different diameters achieved a greater suppression of tumor growth in comparison to treatment with single-size TNP-470-loaded CPMs alone, and the control. Severe loss of body weight was not observed in any mice treated with any size of TNP-470-loaded CPMs. These results suggest that treatment with a mixture of differently-sized anti-angiogenic CPMs might be more effective than treatment with CPMs of a single size. This advanced chemoembolization method, which incorporated an anti-angiogenic agent to target the morphological vascular heterogeneity of tumors may contribute to effective treatment of locally advanced or recurrent solid tumors.

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.

Specific cell targeting with APRPG conjugated PEG-PLGA nanoparticles for treating ovarian cancer.

Good biocompatibility, specific tumor targeting, effective drug loading capacity and persistence in the circulation in vivo are imperative prerequisites for the antitumor efficiency of nanoparticles and their further clinical application. In this study, APRPG (Ala-Pro-Arg-Pro-Gly) peptide-modified poly (ethylene glycol)-poly (lactic acid) (PEG-PLA) nanoparticles (NP-APRPG) encapsulating inhibitors of angiogenesis (TNP-470) (TNP-470-NP-APRPG) were fabricated. TNP-470-NP-APRPG was designed to feature maleimide-PEG-PLA and mPEG-PLA as carrier materials, the APRPG peptide for targeting angiogenesis, PEG for prolonging circulation in vivo and PLA for loading TNP-470. TNP-470-NP-APRPG was confirmed to be approximately 130 nm in size with negative ζ-potential (-14.3 mV), narrow distribution (PDI = 0.27) and spherical morphology according to dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses. In addition, X-ray photoelectron spectra (XPS) analyses confirmed 7.73% APRPG grafting on the TNP-470-NP. In vitro, TNP-470-NP-APRPG exhibited effective inhibition of proliferation, migration and tube formation in human umbilical vein endothelial cells (HUVECs). Similar findings were observed for the retardation of tumor growth in SKOV3 ovarian cancer-bearing mice, suggesting the significant inhibition of angiogenesis and antitumor efficiency of TNP-470-NP-APRPG. Moreover, no obvious toxic drug responses were observed. Further evidence obtained from the immunohistochemical examination demonstrated that the tumor growth inhibition was closely correlated with the high rate of apoptosis among endothelial cells and the effective blockade of endothelial cell proliferation. These results demonstrate that NP-APRPG is a promising carrier for delivering TNP-470 to treat ovarian cancer and that this approach has the potential to achieve broad tumor coverage in the clinic.

Preclinical therapeutic response of residual metastatic disease is distinct from its primary tumor of origin.

Cancer-related deaths are caused principally by recurrence and metastasis arising from residual disease, whose therapeutic responses has been suggested to be substantially different from primary tumors. However, experimental animal models designed for evaluating the therapeutic responses of residual disease are mostly lacking. To overcome this deficiency, we have developed a preclinical model that recapitulates the progression for advanced nonsmall cell lung cancer (NSCLC). An archived Lewis lung carcinoma mouse tumor, propagated only through serial in vivo transplantation and never adapted to cell culture, was stably labeled using lentivirus-encoded biomarkers, consistently expressed through an RNA polymerase II promoter. Labeled tumors were inoculated into syngeneic immunocompetent mice to ensure superior tumor-host interactions. Primary tumors were resected on reaching a predetermined size, followed by treatment in a setting akin to postsurgical first-line adjuvant chemotherapy and routine imaging to monitor the progression of pulmonary metastasis. We discovered that efficacious treatment, instead of reducing disease growth rates, significantly prolonged disease-free survival and overall survival. As in the clinic, cisplatin-based regimes were more effective in this model. However, the response of metastases to specific agents could not be predicted from, and often opposed, their effects on subcutaneous "primary" tumors, possibly due to their distinct growth kinetics and host interactions. We here introduce a clinically relevant model of residual metastatic disease that may more accurately predict the therapeutic response of recurrent, metastatic disease.

Metronomic doxifluridine chemotherapy combined with the anti-angiogenic agent TNP-470 inhibits the growth of human uterine carcinosarcoma xenografts.

Uterine carcinosarcoma is a highly aggressive gynecological neoplasm that responds poorly to conventional chemotherapy and radiotherapy. Metronomic chemotherapy is accepted as a new approach for cancer treatment, and its underlying mechanism seems to involve the suppression of angiogenesis. However, the efficacy of metronomic and anti-angiogenic therapies against uterine carcinosarcoma is unknown. The anti-angiogenic effect of doxifluridine was assessed in vitro using human umbilical vein endothelial cells (HUVEC) co-cultured with FU-MMT-1 human uterine carcinosarcoma cells. The antitumor and anti-angiogenic effects of metronomic doxifluridine (delivered via oral gavage) in combination with TNP-470 were evaluated in vivo. Tumor vascularity was assessed by contrast-enhanced color Doppler ultrasound, laser Doppler and microvessel density staining. Doxifluridine suppressed tube formation of HUVEC and vascular endothelial growth factor production by FU-MMT-1 cells. Metronomic doxifluridine alone significantly suppressed tumor growth compared with the untreated (control) group, while metronomic doxifluridine in combination with TNP-470 significantly inhibited tumor growth compared with each treatment alone. A significant reduction of intratumoral vascularity was observed in FU-MMT-1 xenografts following treatment with metronomic doxifluridine in combination with TNP-470, as compared with each treatment alone. Intestinal bleeding was only observed when the maximum tolerated dose of doxifluridine was administered in combination with TNP-470. Metronomic doxifluridine chemotherapy in combination with TNP-470 might be effective for uterine carcinosarcoma without marked toxicity, possibly acting via its potent anti-angiogenic effects. Clinical studies are needed to evaluate the safety and efficacy of this treatment in humans.

Enhanced anti-tumor activity and safety profile of targeted nano-scaled HPMA copolymer-alendronate-TNP-470 conjugate in the treatment of bone malignances.

Bone neoplasms, such as osteosarcoma, exhibit a propensity for systemic metastases resulting in adverse clinical outcome. Traditional treatment consisting of aggressive chemotherapy combined with surgical resection, has been the mainstay of these malignances. Therefore, bone-targeted non-toxic therapies are required. We previously conjugated the aminobisphosphonate alendronate (ALN), and the potent anti-angiogenic agent TNP-470 with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer. HPMA copolymer-ALN-TNP-470 conjugate exhibited improved anti-angiogenic and anti-tumor activity compared with the combination of free ALN and TNP-470 when evaluated in a xenogeneic model of human osteosarcoma. The immune system has major effect on toxicology studies and on tumor progression. Therefore, in this manuscript we examined the safety and efficacy profiles of the conjugate using murine osteosarcoma syngeneic model. Toxicity and efficacy evaluation revealed superior anti-tumor activity and decreased organ-related toxicities of the conjugate compared with the combination of free ALN plus TNP-470. Finally, comparative anti-angiogenic activity and specificity studies, using surrogate biomarkers of circulating endothelial cells (CEC), highlighted the advantage of the conjugate over the free agents. The therapeutic platform described here may have clinical translational relevance for the treatment of bone-related angiogenesis-dependent malignances.

Inhibitory effects of TNP-470 in combination with BCNU on tumor growth of human glioblastoma xenografts.

This study investigated the effect of TNP-470 in combination with carmustine (BCNU) on the growth of subcutaneously implanted human glioblastoma xenografts in nude mice. Human glioblastoma U-251 cells (1×10(7)) were injected into 24 nude mice subcutaneously. The tumor-bearing mice were randomly divided into 4 groups on the seventh day following tumor implantation: TNP-470 group, in which TNP-470 was given 30 mg/kg subcutaneously every other day 7 times; BCNU group, in which 20 mg/kg BCNU were injected into peritoneal cavity per 4 days 3 times; TNP-470 plus BCNU group, in which TNP-470 and BCNU were coadministered in the same manner as in the TNP-470 group and the BCNU group; control group, in which the mice were given 0.2 mL of the mixture including 3% ethanol, 5% acacia and 0.9% saline subcutaneously every other day 7 times. The tumor size and weights were measured. The tumor microvessel density (MVD) was determined by immunostaining by using goat-anti-mouse polyclonal antibody CD105. The results showed that on the 21th day following treatment, the volume of xenografts in the TNP-470 plus BCNU group was (108.93±17.63)mm(3), markedly lower than that in the TNP-470 group [(576.10±114.29)mm(3)] and the BCNU group [(473.01±48.04)mm(3)] (both P<0.01). And the xenograft volume in these 3 treatment groups was even much lower than that in the control group [(1512.61±470.25) mm(3)] (all P<0.01). There was no significant difference in the volume of xenografts between the TNP-470 group and the BCNU group (P>0.05). The inhibition rate of the tumor growth in the TNP-470 plus BCNU group was (92.80±11.37)%, notably higher than that in the TNP-470 group [(61.91±6.29)%] and the BCNU group [(68.73±9.65)%] (both P<0.01) on the 21th day following treatment. There was no significant difference in the inhibition rate of tumor growth between the TNP-470 group and the BCNU group (P>0.05). The MVD of xenografts in the TNP-470 plus BCNU group was decreased significantly as compared with that in the TNP-470 group or the BCNU group (both P<0.05). The MVD of xenografts in the 3 treatment groups was markedly reduced as compared with that in the control group (all P<0.05). No significant changes in weights were observed before and after the treatment in each group (all P>0.05). It was concluded that the combination of TNP-470 and BCNU can significantly inhibit the growth of human glioblastoma xenografts in nude mice without evident side effects.

Broad spectrum antiangiogenic treatment for ocular neovascular diseases.

UNLABELLED: Pathological neovascularization is a hallmark of late stage neovascular (wet) age-related macular degeneration (AMD) and the leading cause of blindness in people over the age of 50 in the western world. The treatments focus on suppression of choroidal neovascularization (CNV), while current approved therapies are limited to inhibiting vascular endothelial growth factor (VEGF) exclusively. However, this treatment does not address the underlying cause of AMD, and the loss of VEGF's neuroprotective can be a potential side effect. Therapy which targets the key processes in AMD, the pathological neovascularization, vessel leakage and inflammation could bring a major shift in the approach to disease treatment and prevention. In this study we have demonstrated the efficacy of such broad spectrum antiangiogenic therapy on mouse model of AMD. METHODS AND FINDINGS: Lodamin, a polymeric formulation of TNP-470, is a potent broad-spectrum antiangiogenic drug. Lodamin significantly reduced key processes involved in AMD progression as demonstrated in mice and rats. Its suppressive effects on angiogenesis, vascular leakage and inflammation were studied in a wide array of assays including; a Matrigel, delayed-type hypersensitivity (DTH), Miles assay, laser-induced CNV and corneal micropocket assay. Lodamin significantly suppressed the secretion of various pro-inflammatory cytokines in the CNV lesion including monocyte chemotactic protein-1 (MCP-1/Ccl2). Importantly, Lodamin was found to regress established CNV lesions, unlike soluble fms-like tyrosine kinase-1 (sFlk-1). The drug was found to be safe in mice and have little toxicity as demonstrated by electroretinography (ERG) assessing retinal and by histology. CONCLUSIONS: Lodamin, a polymer formulation of TNP-470, was identified as a first in its class, broad-spectrum antiangiogenic drug that can be administered orally or locally to treat corneal and retinal neovascularization. Several unique properties make Lodamin especially beneficial for ophthalmic use. Our results support the concept that broad spectrum antiangiogenic drugs are promising agents for AMD treatment and prevention.

Reversal of TNP-470-induced endothelial cell growth arrest by guanine and guanine nucleosides.

The mechanism of action of TNP-470 [O-(chloroacetyl-carbamoyl) fumagillol], which potently and selectively inhibits the proliferation of endothelial cells, is incompletely understood. Previous studies have established its binding protein and the most distal effector of its growth arrest activity as methionine aminopeptidase 2 (MetAP-2) and p21(WAF1/CIP1), respectively. However, the mechanistic steps between these two effectors have not been identified. We have found that addition of exogenous guanine and guanine-containing nucleosides to culture medium will completely reverse the cytostatic effect of TNP-470 on both cultured bovine aortic and mouse pulmonary endothelial cells. Western blotting showed that supplementation with exogenous guanosine reverses the induction of p21(WAF1/CIP1) by TNP-470. This "rescue" by guanine/guanosine was abolished when the guanine salvage pathway of nucleotide biosynthesis was inhibited with Immucillin H, suggesting that TNP-470 might reduce de novo guanine synthesis in endothelial cells. However, an analysis of inosine 5'-monophosphate dehydrogenase, the rate-limiting enzyme in de novo guanine synthesis and target of the antiangiogenic drug mycophenolic acid, showed no TNP-470-induced changes. Curiously, quantitation of cellular nucleotides confirmed that GTP levels were not reduced after TNP-470 treatment. Addition of guanosine at the start of G(1) phase causes a doubling in GTP levels that persists to the G(1)/S phase transition, where commitment to TNP-470 growth arrest occurs. Thus, guanine rescue involves an augmentation of cellular GTP beyond physiological levels rather than a restoration of a drug-induced GTP deficit. Determining the mechanism whereby this causes restoration of endothelial cell proliferation is an ongoing investigation.

Novel chemoembolization using calcium-phosphate ceramic microsphere incorporating TNP-470, an anti-angiogenic agent.

The purpose of the present study was to develop a new method of chemoembolization to improve the therapeutic effectiveness and safety profile of cancer treatment. A chemoembolization approach was designed for human solid tumors using resorbable calcium-phosphate ceramic microspheres loaded with an agent anti-angiogenic to tumor vasculature in vivo. The human uterine sarcoma cell line FU-MMT-3 was used in this study because this tumor is aggressive and also exhibits a poor response to radiotherapy or any chemotherapy currently used. The calcium-phosphate ceramic microspheres loaded with TNP-470, an anti-angiogenic agent, were injected into FU-MMT-3 xenografts in nude mice three times per week for 8 weeks. The treatment using TNP-470-loaded microspheres suppressed tumor growth, compared to treatment with TNP-470 alone, microspheres alone, and the control. The mean tumor weight after treatment using TNP-470-loaded microspheres was significantly lower than that after treatment with microspheres alone. These ceramic microspheres were remarkably embolized in tumor microvessels as well as in the feeding arteries and a significant reduction of intratumoral vascularity was also demonstrated following treatment with TNP-470-loaded microspheres. Severe loss of body weight was not observed in any mice treated with the TNP-470-loaded microspheres, compared to treatment with TNP-470 alone. These results suggest that targeting tumor vasculature in human uterine sarcoma using calcium-phosphate microspheres might be more effective and safer than the treatment that employs anti-angiogenic agent alone. This new chemoembolization method incorporating an anti-angiogenic agent may contribute to the effective treatment of locally advanced or recurrent solid tumors.

Anti-tumor effect of angiogenesis inhibitor TNP-470 and 5-FU combined therapy on human gastric cancer xenograft.

BACKGROUND/AIMS: TNP-470, an angiogenesis inhibitor, has already been used in combination with chemotherapy to enhance its antitumor activity. The mechanism of enhanced antitumor activity in combination therapy has not been clarified, however, and few studies have described the combined effect of TNP-470 and 5-fluorouracil (5-FU) on gastric cancer. The present study was conducted to investigate the effect of TNP-470 + 5-FU on gastric cancer cell line MKN-45 in vivo and in vitro. METHODOLOGY: MKN-45 cells were subcutaneously injected into mice that were divided into 4 groups: a control group, a 5-FU treated group, a TNP-470 treated group, and a 5-FU + TNP-470 treated group. After the inoculation, the volume of subcutaneous tumors was measured. Blood and lymphatic vessels were also analyzed for the assessment of lymphangiogenesis. RESULTS: Compared with 5-FU or TNP-470 alone, the combined effect of TNP-470 and 5-FU significantly inhibited and suppressed tumor growth in a synergistic fashion. The combined therapy significantly suppressed both angiogenesis and lymphagenesis. CONCLUSIONS: The study suggests that the combined therapy provides an enhanced antitumor effect on human gastric cancer. The enhanced antitumor activity is explained mainly by the stronger inhibition of angiogenesis.

Angiogenesis inhibition as a therapeutic approach for inflammatory synovitis.

Angiogenesis inhibition, long studied in the treatment of malignancies, has begun to emerge as a potential therapeutic approach in managing inflammatory arthritis, particularly rheumatoid arthritis. The growth of new vessels is required for the development of the rheumatoid pannus, which then leads to extensive synovial inflammation and joint destruction. Vascular endothelial growth factor is the best studied mediator of angiogenesis, and several therapies have been developed that specifically target this molecule. Several other angiogenesis mediators, such as the angiopoietin-TIE system, hypoxia inducible factor and integrin alpha(V)beta(3), as well as naturally occurring inhibitors of angiogenesis, are also being investigated as potential therapeutic targets. Additionally, there are a number of drugs, including paclitaxel, 2-methoxyestradiol and fumagillin analogs, that might have a role in inhibiting angiogenesis and, thus, in treating proliferative synovitis.

Antitumor effect of TNP-470, an angiogenesis inhibitor, combined with ultrasound irradiation for human uterine sarcoma xenografts evaluated using contrast color Doppler ultrasound.

Microvascular endothelial cells, which are recruited by tumors, have become an important target in cancer therapy. This study firstly examined the antitumor effect of angiogenesis inhibitor combined with ultrasound (US) irradiation for human cancer in vivo and evaluated its vascularity using color Doppler US in real time with a microbubble US contrast agent. A human uterine sarcoma cell line, FU-MMT-1, was used in vivo because this tumor is one of the most malignant neoplasms of the human solid tumors and it also has a poor response to any of the chemotherapeutic agents currently used, as well as to radiotherapy. In angiogenic inhibitors, TNP-470 was selected to use in an in vivo study, because this agent showed a higher inhibitory effect in tube formation assay in vitro, than that of FR118487, or thalidomide. The FU-MMT-1 xenografts in nude mice were treated using US at a low-intensity (2.0 w/cm(2), 1MHZ) for 4 min three times per week each after the subcutaneous injection of TNP-470 (30 mg/kg), an angiogenesis inhibitor, and this treatment was continued for 8 weeks. Either treatment of US alone or TNP-470 alone showed a suppression of tumor growth, in comparison to the non-treatment group (control), and a significantly enhanced effect was obtained using the combined treatment. A reduction in the intratumoral vascularity, which was evaluated using both color Doppler and immunohistochemistry, was significantly demonstrated using the combined treatment, in comparison to each treatment alone, and the control. No side-effect was observed in any mice in the combined treatment group. These results suggest that the antitumor effect of TNP-470 for uterine sarcoma was accelerated by US irradiation in vivo and this combination might be a potentially effective for new cancer therapy.

Assessment of the anti-obesity effects of the TNP-470 analog, CKD-732.

The systemic treatment with angiogenesis inhibitor has been shown to result in weight reduction and adipose tissue loss in various models of obesity. To verify the mechanism of CKD-732 (TNP-470 analog) against obesity, we evaluated CKD-732's peripheral and central anti-obesity effects. CKD-732 was injected subcutaneously (s.c.) for 7 days in various animal models and intracerebroventricularly (i.c.v.) in arcuate nucleus (ARC) lesion mice, ob/ob mice, and normal littermates. Modulation of the hypothalamic neuropeptide mRNAs after i.c.v. injection was evaluated in ARC lesion mice and normal littermates. A conditioned taste aversion (CTA) was performed using lithium chloride (LiCl) as a positive control agent in Long-Evans Tokushima Otsuka and Otsuka Long-Evans Tokushima fatty (OLETF) rats. As a result, 7 days of CKD-732 s.c. injection reduced the cumulative food intake and the body weight significantly in both treated obese (e.g. 114.8 +/- 13.4 g vs 170.7 +/- 20.6 g, 7.9 +/- 0.5% decrease vs 0.3 +/- 2.2% decrease; in treated OLETF rat versus control OLETF rat, P < 0.01 respectively) and non-obese models. Epididymal and mesenteric fat pads, and the size of adipocytes were significantly decreased in treated rats. A single i.c.v. injection decreased food intake and body weight in ARC lesion mice and ob/ob mice but not in normal littermates. Unexpectedly, the hypothalamic neuropeptide mRNAs were not altered by single i.c.v. injection. CKD-732 also induced a dose-dependent CTA comparable with LiCl injection, which is a commonly used agent to produce a CTA. In conclusion, CKD-732 causes significant body weight and appetite reduction, possibly by decreasing adiposity directly and inducing central anorexia, which is partly explained by a CTA. These results should be carefully verified to assess the utility of CKD-732 as an anti-obesity drug.

A mechanism-based combination therapy reduces local tumor growth and metastasis in an orthotopic model of prostate cancer.

Therapy-induced stimulation of angiogenic molecules can promote tumor angiogenesis leading to enhanced tumor growth and cancer metastasis. Several standard and emerging therapies, such as radiation and photodynamic therapy (PDT), can induce angiogenic molecules, thus limiting their effectiveness. PDT is approved for the treatment of several cancers; however, its induction of vascular endothelial growth factor (VEGF) creates conditions favorable to enhanced tumor growth and metastasis, therefore mitigating its cytotoxic and antivascular effects. This is the first report showing that subcurative PDT in an orthotopic model of prostate cancer (LNCaP) increases not only VEGF secretion (2.1-fold) but also the fraction of animals with lymph node metastases. PDT followed by administration of an antiangiogenic agent, TNP-470, abolished this increase and reduced local tumor growth. On the other hand, administration of TNP-470 before PDT was less effective at local tumor control. In addition, animals in all groups, except in the PDT + TNP-470 group, had a weight loss of >3 g at the time of sacrifice; the weight of the animals in the PDT + TNP-470 group did not change. The significant reduction (P < 0.05) in tumor weight and volume observed between the PDT + TNP-470 group and the control group suggests that the combination of PDT and antiangiogenic treatment administered in the appropriate sequence was not only more effective at controlling local tumor growth and metastases but also reduced disease-related toxicities. Such molecular response-based combinations merit further investigations as they enhance both monotherapies and lead to improved treatment outcomes.

Synergistic antitumor effect of an angiogenesis inhibitor (TNP-470) and tumor necrosis factor in mice.

PURPOSE: We investigated the potentiation of combination therapy using tumor necrosis factor (TNF) with TNP-470, a potent angiogenesis inhibitor. METHODS: We evaluated the antitumor effect in vivo against subcutaneous (s.c.) MC38 mouse colon adenocarcinoma tumors in C57BL/6 mice. The mice were treated with a single bolus injection via the tail vein of 3 or 8 microg rhTNF in 0.5% bovine serum albumin/normal saline (BSA/NS), or with 0.5% BSA/NS alone as a control, with or without TNP-470 pretreatment, given as 30 or 60 mg/kg x 2 days, s.c. DNA synthesis in human umbilical endothelial cells (HUVEC) was assessed by [(3)H]thymidine uptake after incubation with TNF, with or without TNP-470. RESULTS: The antitumor effect of TNP-470 pretreatment combined with 3 microg recombinant human (rh) TNF injection resulted in an 80% reduction of tumor volume compared with the control. This was significantly better than that induced by 3 microg rhTNF alone (P < 0.005). DNA synthesis in HUVEC was inhibited by TNF with TNP-470 in a dose-dependent manner, but there was no enhanced effect against MC38 in vitro. CONCLUSIONS: These results suggest that the combination of the angiogenesis inhibitor TNP-470 and TNF might have a synergistic antitumor effect on solid tumors in vivo.

Inhibition of expression of vascular endothelial growth factor and its receptors in pulmonary adenocarcinoma cell by TNP-470 in combination with gemcitabine.

Angiogenesis is required for solid tumor growth and facilitates tumor progression and metastasis. The inhibition effects of O-(chloroacetyl-carbamoyl) fumagillol (TNP-470), an angiogenesis inhibitor, and gemcitabine, a chemotherapeutic agent, on expression of growth factors were investigated using human pulmonary adenocarcinoma cell line, A549. The A549 cells were divided into four groups: control group, 10(-6) mg/ml gemcitabine treated group, 10(-4) mg/ml TNP-470 treated group and gemcitabine+TNP-470 treated group. The mRNA and protein expression of vascular endothelial growth factor (VEGF) and its receptors, FMS-like tyrosine kinase-1 (FLT-1) and kinase insert domain-containing receptor (KDR), in different groups were measured. The growth of A549 cell cultured with gemcitabine or TNP-470 was inhibited in an almost dose-dependent manner. Although gemcitabine (10(-6) mg/ml) alone and TNP-470 (10(-4) mg/ml) alone had no effect on the mRNA and protein expression of VEGF and its receptors (FLT-1, KDR) in A549 cells compared to the control (P>0.05), 10(-6) mg/ml gemcitabine in combination with 10(-4) mg/ml TNP-470 had significant effect (P<0.01). Moreover, combination of the two drugs significantly inhibited the mRNA expression of VEGF, FLT-1 and KDR compared to either drug alone (P<0.05). This study suggests that combined treatment with TNP-470 plus gemcitabine may augment the antiangiogenic and antineoplastic effects in lung cancer cells in vitro.