pazopanib and Disease-Models--Animal

In order to identify more effective therapy for recalcitrant osteosarcoma, we evaluated the efficacy of an mTOR-VEGFR inhibitor combination on tumor growth in a unique osteosarcoma patient-derived orthotopic xenograft (PDOX) mouse model derived from the lung metastasis of an osteosarcoma patient who failed doxorubicin therapy. We also determined the efficacy of this inhibitor combination on angiogenesis using an in vivo Gelfoam fluorescence angiogenesis mouse model implanted with osteosarcoma patient-derived cells (OS-PDCs). PDOX models were randomly divided into five groups of seven nude mice. Group 1, control; Group 2, doxorubicin (DOX); Group 3, everolimus (EVE, an mTOR and VEGF inhibitor); Group 4, pazopanib (PAZ, a VEGFR inhibitor); Group 5, EVE-PAZ combination. Tumor volume and body weight were monitored 2 times a week. The in vivo Gelfoam fluorescence angiogenesis assay was performed with implanted OS-PDCs. The nude mice with implanted Gelfoam and OSPDCs also were divided into the four therapeutic groups and vessel length was monitored once a week. The EVE-PAZ combination suppressed tumor growth in the osteosarcoma PDOX model and decreased the vessel length ratio in the in vivo Gelfoam fluorescent angiogenesis model, compared with all other groups (p < 0.05). There was no significant body-weight loss in any group. Only the EVE-PAZ combination caused tumor necrosis. The present study demonstrates that a combination of an mTOR-VEGF inhibitor and a VEGFR inhibitor was effective for a DOX-resistant lung-metastatic osteosarcoma PDOX mouse model, at least in part due to strong anti-angiogenesis efficacy of the combination.

Topics: Adolescent; Animals; Antibiotics, Antineoplastic; Bone Neoplasms; Disease Models, Animal; Doxorubicin; Drug Resistance, Neoplasm; Drug Therapy, Combination; Everolimus; Female; Humans; Indazoles; Lung Neoplasms; Mice; Mice, Nude; Neoplasm Transplantation; Neovascularization, Pathologic; Osteosarcoma; Pyrimidines; Receptors, Vascular Endothelial Growth Factor; Sulfonamides; TOR Serine-Threonine Kinases

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Age-related macular degeneration (AMD) is the leading cause of severe vision impairment in patients over the age of 60 years. Choroidal neovascularization (CNV) is the hallmark of neovascular AMD and vascular endothelial growth factor (VEGF) plays a causal role in the formation of CNV. Although regorafenib and pazopanib, small molecule VEGF receptor (VEGFR) inhibitors, were developed as eye-drops, their efficacies were insufficient in clinical. In this study, we evaluated ocular pharmacokinetics and pharmacological activities of regorafenib and pazopanib after ocular instillation in multiple animal species. In rats, both regorafenib and pazopanib showed high enough concentrations in the posterior eye tissues to inhibit VEGFR. In laser-induced rat CNV model, regorafenib showed clear reduction in CNV area. On the other hand, the concentrations of regorafenib and pazopanib in the posterior eye tissues were much lower after ocular instillation in rabbits and monkeys compared to those in rats. Pazopanib did not show any improvement in monkey model. Regorafenib was nano-crystalized to improve its drug delivery to the posterior eye tissues. The nano-crystalized formulation of regorafenib showed higher concentrations in the posterior segments in rabbits compared to its microcrystal suspension. From these studies, large interspecies differences were found in ocular delivery to the posterior segments after ocular instillation. Such large interspecies difference could be the reason for the insufficient efficacies of regorafenib and pazopanib in clinical studies. Nano-crystallization was suggested to be one of the effective ways to overcome this issue.

Topics: Angiogenesis Inhibitors; Animals; Choroidal Neovascularization; Crystallization; Disease Models, Animal; Drug Evaluation, Preclinical; Eye; Female; Humans; Indazoles; Macaca fascicularis; Macular Degeneration; Male; Nanoparticles; Ophthalmic Solutions; Particle Size; Phenylurea Compounds; Pyridines; Pyrimidines; Rabbits; Rats; Receptors, Vascular Endothelial Growth Factor; Species Specificity; Sulfonamides; Vascular Endothelial Growth Factor A

Vandetanib and pazopanib are clinically available, multi-targeted inhibitors of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) receptor tyrosine kinases. Short-term VEGF receptor inhibition is associated with hypertension in 15%-60% of patients, which may limit the use of these anticancer therapies over the longer term. To evaluate the longer-term cardiovascular implications of treatment, we investigated the "on"-treatment (21 days) and "off"-treatment (10 days) effects following daily administration of vandetanib, pazopanib, or vehicle, in conscious rats. Cardiovascular variables were monitored in unrestrained Sprague-Dawley rats instrumented with radiotelemetric devices. In Study 1, rats were randomly assigned to receive either daily intraperitoneal injections of vehicle (volume 0.5 mL; n = 5) or vandetanib 25 mg/kg/day (volume 0.5 mL; n = 6). In Study 2, rats received either vehicle (volume 0.5 mL; n = 4) or pazopanib 30 mg/kg/day (volume 0.5 mL; n = 7), dosed once every 24 hours for 21 days. All solutions were in 2% Tween, 5% propylene glycol in 0.9% saline solution. Vandetanib caused sustained increases in mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) compared to baseline and vehicle. Vandetanib also significantly altered the circadian cycling of MAP, SBP, and DBP. Elevations in SBP were detectable 162 hours after the last dose of vandetanib. Pazopanib also caused increases in MAP, SBP, and DBP. However, compared to vandetanib, these increases were of slower onset and a smaller magnitude. These data suggest that the cardiovascular consequences of vandetanib and pazopanib treatment are sustained, even after prolonged cessation of drug treatment.

Topics: Animals; Arterial Pressure; Disease Models, Animal; Drug Administration Schedule; Humans; Hypertension; Indazoles; Male; Piperidines; Pyrimidines; Quinazolines; Random Allocation; Rats; Rats, Sprague-Dawley; Sulfonamides

Liposarcoma (LS) is a chemotherapy-resistant disease. The aim of the present study was to find precise therapy for a recurrent dedifferentiated liposarcoma (DDLS) in a patient-derived orthotopic xenograft (PDOX) model. The DDLS PDOX models were established orthotopically in the right inguinal area of nude mice. The DDLS PDOX models were randomized into five groups: untreated; doxorubicin (DOX); gemcitabine (GEM) combined with docetaxel (DOC); pazopanib (PAZ); and yondelis (YON). On day 15, all mice were sacrificed. Measurement of tumor volume and body weight were done two times a week. The DDLS PDOX was resistant to DOX (P > 0.184). YON suppressed tumor growth significantly compared to control group (P < 0.027). However, only GEM combined with DOC arrested the tumor growth (P < 0.001). These findings suggest that GEM combined with DOC has clinical potential for this and possibly other DDLS patients.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Deoxycytidine; Disease Models, Animal; Docetaxel; Doxorubicin; Drug Resistance, Neoplasm; Gemcitabine; Heterografts; Humans; Indazoles; Liposarcoma; Male; Mice; Mice, Nude; Neoplasm Recurrence, Local; Pyrimidines; Sulfonamides; Tumor Burden; Xenograft Model Antitumor Assays

In the setting of metastatic RCC (mRCC), pazopanib is approved as first line therapy. Unfortunately treatment may lead to cardiotoxicity such as hypertension, heart failure, and myocardial ischemia.. Define the in vivo role of pazopanib in the development of cardiotoxicity.. Wild type mice were dosed for 42 days via oral gavage, and separated into control and treatment (pazopanib) groups. Baseline ECG's, echocardiograms, and blood pressures were recorded. At the conclusion of the study functional parameters were again recorded, and animals were used for pathological, histological, and protein analysis.. After 2 weeks of dosing with pazopanib, the treatment group exhibited a statistically significant increase in mean arterial pressure compared to control mice (119 ± 11.7 mmHg versus 108 ± 8.2 mmHg, p = 0.049). Treatment with pazopanib led to a significant reduction in the cardiac output of mice.. Our findings in mice clearly demonstrate that treatment with pazopanib leads to a significant elevation in blood pressure after 2 weeks of dosing and this persists for the duration of dosing. The continued development of the cardio-oncology field will be paramount in providing optimal oncologic care while simultaneously improving cardiac outcomes through further investigation into the mechanisms of CV toxicity.

Topics: Angiogenesis Inhibitors; Animals; Arterial Pressure; Body Weight; Carcinoma, Renal Cell; Cardiac Output; Disease Models, Animal; Echocardiography; Electrocardiography; Heart; Hypertension; Indazoles; Kidney; Kidney Neoplasms; Mice; Myocardium; Pyrimidines; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Sulfonamides; Vascular Endothelial Growth Factor A

Mycobacterial infection leads to the formation of characteristic immune aggregates called granulomas, a process accompanied by dramatic remodeling of the host vasculature. As granuloma angiogenesis favors the infecting mycobacteria, it may be actively promoted by bacterial determinants during infection. Using Mycobacterium marinum-infected zebrafish as a model, we identify the enzyme proximal cyclopropane synthase of alpha-mycolates (PcaA) as an important bacterial determinant of granuloma-associated angiogenesis. cis-Cyclopropanation of mycobacterial mycolic acids by pcaA drives the activation of host Vegf signaling within granuloma macrophages. Cyclopropanation of the mycobacterial cell wall glycolipid trehalose dimycolate is both required and sufficient to induce robust host angiogenesis. Inducible genetic inhibition of angiogenesis and Vegf signaling during granuloma formation results in bacterial growth deficits. Together, these data reveal a mechanism by which PcaA-mediated cis-cyclopropanation of mycolic acids promotes bacterial growth and dissemination in vivo by eliciting granuloma vascularization and suggest potential approaches for host-directed therapies.

Topics: Angiogenesis Inhibitors; Animals; Bacterial Proteins; Cord Factors; Disease Models, Animal; Humans; Indazoles; Macrophages; Methyltransferases; Mycobacterium Infections, Nontuberculous; Mycobacterium marinum; Mycolic Acids; Neovascularization, Pathologic; Pyrimidines; Receptors, Vascular Endothelial Growth Factor; Signal Transduction; Sulfonamides; Tuberculoma; Zebrafish

Essentials Antiangiogenic drugs are indicated as therapies for hereditary hemorrhagic telangiectasia. We interrogated the response to four antiangiogenic drugs for anemia and intestinal bleeding. Sorafenib and a pazopanib analog significantly improved while erlotinib worsened anemia. Some oral antiangiogenic drugs were effective in reducing intestinal bleeding.. Background Epistaxis and gastrointestinal (GI) tract hemorrhages are common symptoms of aged hereditary hemorrhagic telangiectasia (HHT) patients that result in anemia. Clinical as well as animal studies have suggested that vascular endothelial growth factor (VEGF) neutralizing antibodies lessen hemorrhage associated with adult-onset arteriovenous malformations (AVMs). Objectives The goal of this study is to evaluate potential therapeutic effects of oral delivery of four antiangiogenic tyrosine-kinase inhibitors (TKIs) in the development of adult-onset AVMs in a murine model of HHT. Methods An adult activin receptor-like kinase 1 (Alk1)-inducible knockout (iKO) model was utilized to evaluate the effect of oral administration of sorafenib, sunitinib, erlotinib and a pazopanib analog (GW771806) on hemoglobin level, GI hemorrhages and formation of wound-induced skin AVMs. Results and Conclusions Sorafenib and GW771806 significantly improved, yet erlotinib worsened, anemia and GI-bleeding in the Alk1-iKO model. However, none of these TKIs appeared to be effective for inhibiting the development of wound-induced skin AVMs. Taken together, these results suggest that oral delivery of antiangiogenic TKIs is selectively more effective for GI bleeding than mucocutaneous AVMs, and it may provide an experimental basis for selective therapeutic options depending on the symptoms of HHT.

Topics: Activin Receptors, Type I; Activin Receptors, Type II; Administration, Oral; Administration, Topical; Anemia; Angiogenesis Inhibitors; Animals; Arteriovenous Malformations; Disease Models, Animal; Erlotinib Hydrochloride; Gastrointestinal Hemorrhage; Hemoglobins; Image Processing, Computer-Assisted; Indazoles; Mice; Mice, Knockout; Niacinamide; Phenylurea Compounds; Protein Kinase Inhibitors; Pyrimidines; Skin; Sorafenib; Sulfonamides; Sulfones; Telangiectasia, Hereditary Hemorrhagic; Tyrosine; Vascular Endothelial Growth Factor A; Wound Healing

To compare the efficacy of microneedle-delivered suprachoroidal (SC) pazopanib to intravitreal (Ivit) delivery of pazopanib, bevacizumab, or a fusion protein hI-con1 versus vehicle controls on choroidal neovascularization (CNV) growth in a pig model.. Forty-one pigs were injected on the day of CNV induction (hI-con1 on postinduction day 14) with either 2.5 mg Ivit bevacizumab (n = 9), 1 mg Ivit pazopanib (n = 9), 300 Ivit μg hI-con1 (n = 4), or 1 mg SC pazopanib (n = 9), vs. 10 vehicle controls (3 SC + 7 Ivit = 10). Pigs were euthanized at week 2 (11), 3 (8), 4 (11), and 8 (11), and eyes were fixed for histology. The size of the CNV was determined from histology, and CNV height was the primary outcome measure. Immunostaining for cytotoxic T-cells was performed in the hI-con1 study.. In 39 of 41 (95%) eyes, type 2 CNV lesions were identified. One CNV lesion was lost during dissection. One animal was euthanized due to surgical complications. For mean CNV size comparisons, Ivit pazopanib had smaller mean height measurements (90 ± 20 μm) versus controls (180 ± 20 μm; P = 0.009), and Ivit pazopanib had smaller maximum CNV height (173 ± 43 μm) compared to SC pazopanib (478 ± 105 μm; P = 0.018). The mean lesion size in hI-con1-treated animals trended smaller than in controls (P = 0.11). Immunostaining did not detect cytotoxic T-cells.. Intravitreal pazopanib and to a lesser extent hI-con1 reduced the size of CNV lesions. The pig model has nearly a 100% rate of type 2 CNV induction and is a reliable preclinical model with pharmacodynamics similar to humans.

Topics: Angiogenesis Inhibitors; Animals; Bevacizumab; Choroidal Neovascularization; Disease Models, Animal; Fluorescein Angiography; Immunoconjugates; Indazoles; Intravitreal Injections; Pyrimidines; Sulfonamides; Swine; T-Lymphocytes, Cytotoxic; Vascular Endothelial Growth Factor A

Hyperphosphorylation and aggregation of tau protein is a critical factor in many neurodegenerative diseases. These diseases are increasing in prevalence, and there are currently no cures. Previous work from our group and others has shown that tyrosine kinase inhibitors (TKIs) can stimulate autophagy, decrease pathological proteins, and improve symptoms in models of neurodegeneration. Here we examined the role of pazopanib in mouse models that express either human mutant P301L tau (TauP301L) or triple mutant amyloid precursor protein (3x-AβPP). The TauP301L mouse expresses P301L tau under the control of a prion promoter in both neurons and astrocytes, reminiscent of some human tauopathies. Pazopanib crosses the blood-brain barrier with no detectable peripheral off-side effects, and decreases p-tau in TauP301L mice. Pazopanib reaches a brain concentration sufficient for inhibition of several tyrosine kinases, including vascular endothelial growth factor receptors (VEGFRs). Further, pazopanib does not affect microglia but reduces astrocyte levels toward nontransgenic controls in TauP301L mice. Pazopanib does not alter amyloid beta levels or astrocytes in 3x-AβPP mice but modulates a number of inflammatory markers (IP-10, MIP-1α, MIP-1β, and RANTES). These data suggest that pazopanib may be involved in p-tau clearance and modulation of astrocytic activity in models of tauopathies.

Topics: Animals; Astrocytes; Calcium-Binding Proteins; Cell Line, Tumor; Cognition; Collagen Type IV; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Glial Fibrillary Acidic Protein; Indazoles; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microfilament Proteins; Motor Activity; Mutation; Neuroblastoma; Phosphorylation; Pyrimidines; Receptors, Vascular Endothelial Growth Factor; RNA, Small Interfering; Silver Staining; Sulfonamides; tau Proteins; Tauopathies; Transfection; Treatment Outcome

Colon cancer is still the third most common cancer which has a high mortality but low five-year survival rate. Novel tyrosine kinase inhibitors (TKI) such as pazopanib become effective antineoplastic agents that show promising clinical activity in a variety of carcinoma, including colon cancer. However, the precise underlying mechanism against tumor is unclear. Here, we demonstrated that pazopanib promoted colon cancer cell apoptosis through inducing PUMA expression. Pazopanib induced p53-independent PUMA activation by inhibiting PI3K/Akt signaling pathway, thereby activating Foxo3a, which subsequently bound to the promoter of PUMA to activate its transcription. After induction, PUMA activated Bax and triggered the intrinsic mitochondrial apoptosis pathway. Furthermore, administration of pazopanib highly suppressed tumor growth in a xenograft model. PUMA deletion in cells and tumors led to resistance of pazopanib, indicating PUMA-mediated pro-apoptotic and anti-tumor effects in vitro and in vivo. Combing pazopanib with some conventional or novel drugs, produced heightened and synergistic antitumor effects that were associated with potentiated PUMA induction via different pathways. Taken together, these results establish a critical role of PUMA in mediating the anticancer effects of pazopanib in colon cancer cells and provide the rationale for clinical evaluation.

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Cell Line, Tumor; Colonic Neoplasms; Disease Models, Animal; Forkhead Box Protein O3; Gene Expression Regulation, Neoplastic; Humans; Indazoles; Mice; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Pyrimidines; Signal Transduction; Sulfonamides; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays

We aimed to compare the effects of pazopanib, sunitinib, and sorafenib on endometriotic tissue morphology and histological characteristics as well as ovarian reserve in a rat model. Experimental endometriosis was established in 32 rats. They were randomly divided into 4 groups (8 rats for each group) to administer study drugs: pazopanib, sunitinib, sorafenib, and normal saline. Histological examination with hematoxylin and eosin staining to determine endometriosis score and immunostaining with primary vascular endothelial growth factor (VEGF), CD117, and Bax antibodies were performed. Bilateral ovaries excised to determine the ovarian follicle number. The endometriosis score was significantly reduced by pazopanib compared to other study drugs and by sunitinib compared to sorafenib and normal saline (P < .05). Sorafenib did not affect endometriosis score (P > .05). The VEGF score was significantly decreased similarly by pazopanib, sunitinib, and sorafenib compared to normal saline (P < .05). The CD117 score was reduced by pazopanib and sunitinib similarly compared to both sorafenib and normal saline that provided similar effect on the score (P < .05). The Bax scores of all the groups were found similar (P > .05). No study drugs caused meaningful change in the ovarian follicle number (P > .05). Pazopanib reduces the growth of endometriotic implants. This effect may be related to the suppressive effect of pazopanib on the endometriotic tissue expressions of VEGF and CD117 but not Bax. The study drugs do not affect ovarian reserve. The inconsistent effects of study drugs regarding study parameters require further studies to elucidate the molecular bases of their effects on the growth of endometriotic implants.

Topics: Angiogenesis Inhibitors; Animals; Apoptosis; bcl-2-Associated X Protein; Cell Proliferation; Disease Models, Animal; Endometriosis; Endometrium; Female; Indazoles; Indoles; Niacinamide; Ovarian Reserve; Phenylurea Compounds; Proto-Oncogene Proteins c-kit; Pyrimidines; Pyrroles; Rats, Wistar; Signal Transduction; Sorafenib; Sulfonamides; Sunitinib; Vascular Endothelial Growth Factor A

A patient-derived nude-mouse model of soft-tissue sarcoma has been established and treated in the following groups: (1) untreated controls; (2) gemcitabine (GEM) (80 mg/kg, ip, weekly, 3 weeks); (3) Pazopanib (100 mg/kg, orally, daily, 3 weeks) and (4) Salmonella typhimurium A1-R (5 × 10(7) CFU/body, ip, weekly, 3 weeks). The sarcoma was resistant to GEM (p = 0.879). Pazopanib tended to reduce the tumor volume compared to the untreated mice, but there was no significant difference (p = 0.115). S. typhimurium A1-R significantly inhibited tumor growth compared to the untreated mice (p = 0.001). S. typhimurium A1-R was the only effective treatment for the soft-tissue sarcoma nude mouse model among all treatments including a newly approved multiple tyrosine kinase inhibitor; Pazopanib. These results suggest tumor-targeting S. typhimurium A1-R is a promising treatment for chemo-resistant soft-tissue sarcoma.

Topics: Animals; Antineoplastic Agents; Deoxycytidine; Disease Models, Animal; Gemcitabine; Indazoles; Mice; Mice, Nude; Pyrimidines; Salmonella Infections; Salmonella typhimurium; Sarcoma; Soft Tissue Neoplasms; Sulfonamides; Xenograft Model Antitumor Assays

Clear cell sarcoma (CCS) is a therapeutically unresolved, aggressive, soft tissue sarcoma (STS) that predominantly affects young adults. This sarcoma is defined by t(12;22)(q13;q12) translocation, which leads to the fusion of Ewing sarcoma gene (EWS) to activating transcription factor 1 (ATF1) gene, producing a chimeric EWS-ATF1 fusion gene. We established a novel CCS cell line called Hewga-CCS and developed an orthotopic tumor xenograft model to enable comprehensive bench-side investigation for intensive basic and preclinical research in CCS with a paucity of experimental cell lines.. Hewga-CCS was derived from skin metastatic lesions of a CCS developed in a 34-year-old female. The karyotype and chimeric transcript were analyzed. Xenografts were established and characterized by morphology and immunohistochemical reactivity. Subsequently, the antitumor effects of pazopanib, a recently approved, novel, multitargeted, tyrosine kinase inhibitor (TKI) used for the treatment of advanced soft tissue sarcoma, on Hewga-CCS were assessed in vitro and in vivo.. Hewga-CCS harbored the type 2 EWS-ATF1 transcript. Xenografts morphologically mimicked the primary tumor and expressed S-100 protein and antigens associated with melanin synthesis (Melan-A, HMB45). Pazopanib suppressed the growth of Hewga-CCS both in vivo and in vitro. A phospho-receptor tyrosine kinase array revealed phosphorylation of c-MET, but not of VEGFR, in Hewga-CCS. Subsequent experiments showed that pazopanib exerted antitumor effects through the inhibition of HGF/c-MET signaling.. CCS is a rare, devastating disease, and our established CCS cell line and xenograft model may be a useful tool for further in-depth investigation and understanding of the drug-sensitivity mechanism.

Topics: Adult; Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Cell Cycle; Cell Line, Tumor; Cell Survival; Chromosome Breakpoints; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Humans; Indazoles; Mice; Oncogene Proteins, Fusion; Proto-Oncogene Proteins c-met; Pyrimidines; Sarcoma, Clear Cell; Signal Transduction; Soft Tissue Neoplasms; Sulfonamides; Transcription Factors; Tumor Burden; Xenograft Model Antitumor Assays

Cisplatin (CDDP) resistance in testicular germ cell tumors (GCTs) is still a clinical challenge, and one associated with poor prognosis. The purpose of this work was to test pazopanib, an anti-tumoral and anti-angiogenic multikinase inhibitor, and its combination with lapatinib (an anti-ErbB inhibitor) in mouse orthotopic models of human testicular GCTs.. We used two different models of human testicular GCTs orthotopically grown in nude mice; a CDDP-sensitive choriocarcinoma (TGT38) and a new orthotopic model generated from a metastatic GCT refractory to first-line CDDP chemotherapy (TGT44). Nude mice implanted with these orthotopic tumors were treated with the inhibitors and the effect on tumoral growth and angiogenesis was evaluated.. TGT44 refractory tumor had an immunohistochemical profile similar to the original metastasis, with characteristics of yolk sac tumor. TGT44 did not respond when treated with cisplatin. In contrast, pazopanib had an anti-angiogenic effect and anti-tumor efficacy in this model. Pazopanib in combination with lapatinib in TGT38, an orthotopic model of choriocarcinoma had an additive effect blocking tumor growth.. We present pazopanib as a possible agent for the alternative treatment of CDDP-sensitive and CDDP-refractory GCT patients, alone or in combination with anti-ErbB therapies.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Blotting, Western; Disease Models, Animal; Fluorescent Antibody Technique; Humans; Indazoles; Male; Mice; Mice, Nude; Neoplasms, Germ Cell and Embryonal; Pyrimidines; Real-Time Polymerase Chain Reaction; Sulfonamides; Testicular Neoplasms; Xenograft Model Antitumor Assays

Brain metastases of breast cancer contribute significantly to patient morbidity and mortality. We have tested pazopanib, a recently approved antiangiogenic drug that targets VEGFR1, VEGFR2, VEGFR3, PDGFRβ, PDGFRα, and c-kit, for prevention of experimental brain metastases and mechanism of action.. In vitro assays included B-Raf enzymatic assays, Western blots, and angiogenesis assays. For in vivo assays, HER2 transfectants of the brain seeking sublines of MDA-MB-231 cells (231-BR-HER2) and MCF7 cells (MCF7-HER2-BR3, derived herein) were injected into the left cardiac ventricle of mice and treated with vehicle or pazopanib beginning on day 3 postinjection. Brain metastases were counted histologically, imaged, and immunostained.. Treatment with 100 mg/kg of pazopanib resulted in a 73% decline in large 231-BR-HER2 metastases (P < 0.0001) and a 39% decline in micrometastases (P = 0.004). In vitro, pazopanib was directly antiproliferative to 231-BR-HER2 breast cancer cells and inhibited MEK and ERK activation in vitro despite B-Raf and Ras mutations. Enzymatic assays demonstrated that pazopanib directly inhibited the wild type and exon 11 oncogenic mutant, but not the V600E mutant forms of B-Raf. Activation of the B-Raf targets pERK1/2 and pMEK1/2 was decreased in pazopanib-treated brain metastases whereas blood vessel density was unaltered. In the MCF7-HER2-BR3 experimental brain metastasis model, pazopanib reduced overall brain metastasis volume upon magnetic resonance imaging (MRI) by 55% (P = 0.067), without affecting brain metastasis vascular density.. The data identify a new activity for pazopanib directly on tumor cells as a pan-Raf inhibitor and suggest its potential for prevention of brain metastatic colonization of HER2(+) breast cancer.

Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Endothelial Cells; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Indazoles; Mice; Mice, Inbred BALB C; Mice, Nude; Mutation; Proto-Oncogene Proteins B-raf; Pyrimidines; Receptor, ErbB-2; Signal Transduction; Sulfonamides; Xenograft Model Antitumor Assays

To investigate pazopanib hydrochloride, a multitargeted kinase inhibitor, for treatment of choroidal neovascularization (CNV).. Choroidal neovascularization was induced in mice by rupture of Bruch membrane with laser photocoagulation. Mice were treated with pazopanib by gavage or periocular injection, and the area of CNV was measured.. Twice-daily gavage of pazopanib, 100 mg/kg, suppressed the development of CNV by 93%. Treatment of established CNV between days 7 and 14 with 8, 40, or 200 mg/kg per day reduced CNV by 0%, 58%, and 71%, respectively. Substantial regression (40%) of CNV was also achieved after periocular injection of pazopanib. A single oral dose of 4 or 100 mg/kg resulted in an area under the curve from time 0 to the last quantifiable concentration of 129.6 and 752.0 microg x h/mL, respectively. After 7 days of 4, 20, or 100 mg/kg twice a day by gavage, plasma levels were 1300, 4900, and 5800 ng/mL and levels in the retina/choroid were 4800, 28 800, and 38 000 ng/g of tissue.. Orally administered pazopanib has good bioavailability to the retina/choroid and strongly suppresses CNV in mice. Treatment with pazopanib after CNV is established causes dose-dependent regression of CNV.. Pazopanib may be useful for treatment of CNV in humans.

Topics: Administration, Oral; Angiogenesis Inhibitors; Animals; Biological Availability; Choroid; Choroidal Neovascularization; Chromatography, High Pressure Liquid; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Indazoles; Mice; Mice, Inbred C57BL; Protein Kinase Inhibitors; Pyrimidines; Retina; Sulfonamides; Tissue Distribution